diff --git a/vendor/golang.org/x/image/ccitt/reader.go b/vendor/golang.org/x/image/ccitt/reader.go deleted file mode 100644 index 340de05..0000000 --- a/vendor/golang.org/x/image/ccitt/reader.go +++ /dev/null @@ -1,795 +0,0 @@ -// Copyright 2019 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -//go:generate go run gen.go - -// Package ccitt implements a CCITT (fax) image decoder. -package ccitt - -import ( - "encoding/binary" - "errors" - "image" - "io" - "math/bits" -) - -var ( - errIncompleteCode = errors.New("ccitt: incomplete code") - errInvalidBounds = errors.New("ccitt: invalid bounds") - errInvalidCode = errors.New("ccitt: invalid code") - errInvalidMode = errors.New("ccitt: invalid mode") - errInvalidOffset = errors.New("ccitt: invalid offset") - errMissingEOL = errors.New("ccitt: missing End-of-Line") - errRunLengthOverflowsWidth = errors.New("ccitt: run length overflows width") - errRunLengthTooLong = errors.New("ccitt: run length too long") - errUnsupportedMode = errors.New("ccitt: unsupported mode") - errUnsupportedSubFormat = errors.New("ccitt: unsupported sub-format") - errUnsupportedWidth = errors.New("ccitt: unsupported width") -) - -// Order specifies the bit ordering in a CCITT data stream. -type Order uint32 - -const ( - // LSB means Least Significant Bits first. - LSB Order = iota - // MSB means Most Significant Bits first. - MSB -) - -// SubFormat represents that the CCITT format consists of a number of -// sub-formats. Decoding or encoding a CCITT data stream requires knowing the -// sub-format context. It is not represented in the data stream per se. -type SubFormat uint32 - -const ( - Group3 SubFormat = iota - Group4 -) - -// AutoDetectHeight is passed as the height argument to NewReader to indicate -// that the image height (the number of rows) is not known in advance. -const AutoDetectHeight = -1 - -// Options are optional parameters. -type Options struct { - // Align means that some variable-bit-width codes are byte-aligned. - Align bool - // Invert means that black is the 1 bit or 0xFF byte, and white is 0. - Invert bool -} - -// maxWidth is the maximum (inclusive) supported width. This is a limitation of -// this implementation, to guard against integer overflow, and not anything -// inherent to the CCITT format. -const maxWidth = 1 << 20 - -func invertBytes(b []byte) { - for i, c := range b { - b[i] = ^c - } -} - -func reverseBitsWithinBytes(b []byte) { - for i, c := range b { - b[i] = bits.Reverse8(c) - } -} - -// highBits writes to dst (1 bit per pixel, most significant bit first) the -// high (0x80) bits from src (1 byte per pixel). It returns the number of bytes -// written and read such that dst[:d] is the packed form of src[:s]. -// -// For example, if src starts with the 8 bytes [0x7D, 0x7E, 0x7F, 0x80, 0x81, -// 0x82, 0x00, 0xFF] then 0x1D will be written to dst[0]. -// -// If src has (8 * len(dst)) or more bytes then only len(dst) bytes are -// written, (8 * len(dst)) bytes are read, and invert is ignored. -// -// Otherwise, if len(src) is not a multiple of 8 then the final byte written to -// dst is padded with 1 bits (if invert is true) or 0 bits. If inverted, the 1s -// are typically temporary, e.g. they will be flipped back to 0s by an -// invertBytes call in the highBits caller, reader.Read. -func highBits(dst []byte, src []byte, invert bool) (d int, s int) { - // Pack as many complete groups of 8 src bytes as we can. - n := len(src) / 8 - if n > len(dst) { - n = len(dst) - } - dstN := dst[:n] - for i := range dstN { - src8 := src[i*8 : i*8+8] - dstN[i] = ((src8[0] & 0x80) >> 0) | - ((src8[1] & 0x80) >> 1) | - ((src8[2] & 0x80) >> 2) | - ((src8[3] & 0x80) >> 3) | - ((src8[4] & 0x80) >> 4) | - ((src8[5] & 0x80) >> 5) | - ((src8[6] & 0x80) >> 6) | - ((src8[7] & 0x80) >> 7) - } - d, s = n, 8*n - dst, src = dst[d:], src[s:] - - // Pack up to 7 remaining src bytes, if there's room in dst. - if (len(dst) > 0) && (len(src) > 0) { - dstByte := byte(0) - if invert { - dstByte = 0xFF >> uint(len(src)) - } - for n, srcByte := range src { - dstByte |= (srcByte & 0x80) >> uint(n) - } - dst[0] = dstByte - d, s = d+1, s+len(src) - } - return d, s -} - -type bitReader struct { - r io.Reader - - // readErr is the error returned from the most recent r.Read call. As the - // io.Reader documentation says, when r.Read returns (n, err), "always - // process the n > 0 bytes returned before considering the error err". - readErr error - - // order is whether to process r's bytes LSB first or MSB first. - order Order - - // The high nBits bits of the bits field hold upcoming bits in MSB order. - bits uint64 - nBits uint32 - - // bytes[br:bw] holds bytes read from r but not yet loaded into bits. - br uint32 - bw uint32 - bytes [1024]uint8 -} - -func (b *bitReader) alignToByteBoundary() { - n := b.nBits & 7 - b.bits <<= n - b.nBits -= n -} - -// nextBitMaxNBits is the maximum possible value of bitReader.nBits after a -// bitReader.nextBit call, provided that bitReader.nBits was not more than this -// value before that call. -// -// Note that the decode function can unread bits, which can temporarily set the -// bitReader.nBits value above nextBitMaxNBits. -const nextBitMaxNBits = 31 - -func (b *bitReader) nextBit() (uint64, error) { - for { - if b.nBits > 0 { - bit := b.bits >> 63 - b.bits <<= 1 - b.nBits-- - return bit, nil - } - - if available := b.bw - b.br; available >= 4 { - // Read 32 bits, even though b.bits is a uint64, since the decode - // function may need to unread up to maxCodeLength bits, putting - // them back in the remaining (64 - 32) bits. TestMaxCodeLength - // checks that the generated maxCodeLength constant fits. - // - // If changing the Uint32 call, also change nextBitMaxNBits. - b.bits = uint64(binary.BigEndian.Uint32(b.bytes[b.br:])) << 32 - b.br += 4 - b.nBits = 32 - continue - } else if available > 0 { - b.bits = uint64(b.bytes[b.br]) << (7 * 8) - b.br++ - b.nBits = 8 - continue - } - - if b.readErr != nil { - return 0, b.readErr - } - - n, err := b.r.Read(b.bytes[:]) - b.br = 0 - b.bw = uint32(n) - b.readErr = err - - if b.order != MSB { - reverseBitsWithinBytes(b.bytes[:b.bw]) - } - } -} - -func decode(b *bitReader, decodeTable [][2]int16) (uint32, error) { - nBitsRead, bitsRead, state := uint32(0), uint64(0), int32(1) - for { - bit, err := b.nextBit() - if err != nil { - if err == io.EOF { - err = errIncompleteCode - } - return 0, err - } - bitsRead |= bit << (63 - nBitsRead) - nBitsRead++ - - // The "&1" is redundant, but can eliminate a bounds check. - state = int32(decodeTable[state][bit&1]) - if state < 0 { - return uint32(^state), nil - } else if state == 0 { - // Unread the bits we've read, then return errInvalidCode. - b.bits = (b.bits >> nBitsRead) | bitsRead - b.nBits += nBitsRead - return 0, errInvalidCode - } - } -} - -// decodeEOL decodes the 12-bit EOL code 0000_0000_0001. -func decodeEOL(b *bitReader) error { - nBitsRead, bitsRead := uint32(0), uint64(0) - for { - bit, err := b.nextBit() - if err != nil { - if err == io.EOF { - err = errMissingEOL - } - return err - } - bitsRead |= bit << (63 - nBitsRead) - nBitsRead++ - - if nBitsRead < 12 { - if bit&1 == 0 { - continue - } - } else if bit&1 != 0 { - return nil - } - - // Unread the bits we've read, then return errMissingEOL. - b.bits = (b.bits >> nBitsRead) | bitsRead - b.nBits += nBitsRead - return errMissingEOL - } -} - -type reader struct { - br bitReader - subFormat SubFormat - - // width is the image width in pixels. - width int - - // rowsRemaining starts at the image height in pixels, when the reader is - // driven through the io.Reader interface, and decrements to zero as rows - // are decoded. Alternatively, it may be negative if the image height is - // not known in advance at the time of the NewReader call. - // - // When driven through DecodeIntoGray, this field is unused. - rowsRemaining int - - // curr and prev hold the current and previous rows. Each element is either - // 0x00 (black) or 0xFF (white). - // - // prev may be nil, when processing the first row. - curr []byte - prev []byte - - // ri is the read index. curr[:ri] are those bytes of curr that have been - // passed along via the Read method. - // - // When the reader is driven through DecodeIntoGray, instead of through the - // io.Reader interface, this field is unused. - ri int - - // wi is the write index. curr[:wi] are those bytes of curr that have - // already been decoded via the decodeRow method. - // - // What this implementation calls wi is roughly equivalent to what the spec - // calls the a0 index. - wi int - - // These fields are copied from the *Options (which may be nil). - align bool - invert bool - - // atStartOfRow is whether we have just started the row. Some parts of the - // spec say to treat this situation as if "wi = -1". - atStartOfRow bool - - // penColorIsWhite is whether the next run is black or white. - penColorIsWhite bool - - // seenStartOfImage is whether we've called the startDecode method. - seenStartOfImage bool - - // truncated is whether the input is missing the final 6 consecutive EOL's - // (for Group3) or 2 consecutive EOL's (for Group4). Omitting that trailer - // (but otherwise padding to a byte boundary, with either all 0 bits or all - // 1 bits) is invalid according to the spec, but happens in practice when - // exporting from Adobe Acrobat to TIFF + CCITT. This package silently - // ignores the format error for CCITT input that has been truncated in that - // fashion, returning the full decoded image. - // - // Detecting trailer truncation (just after the final row of pixels) - // requires knowing which row is the final row, and therefore does not - // trigger if the image height is not known in advance. - truncated bool - - // readErr is a sticky error for the Read method. - readErr error -} - -func (z *reader) Read(p []byte) (int, error) { - if z.readErr != nil { - return 0, z.readErr - } - originalP := p - - for len(p) > 0 { - // Allocate buffers (and decode any start-of-image codes), if - // processing the first or second row. - if z.curr == nil { - if !z.seenStartOfImage { - if z.readErr = z.startDecode(); z.readErr != nil { - break - } - z.atStartOfRow = true - } - z.curr = make([]byte, z.width) - } - - // Decode the next row, if necessary. - if z.atStartOfRow { - if z.rowsRemaining < 0 { - // We do not know the image height in advance. See if the next - // code is an EOL. If it is, it is consumed. If it isn't, the - // bitReader shouldn't advance along the bit stream, and we - // simply decode another row of pixel data. - // - // For the Group4 subFormat, we may need to align to a byte - // boundary. For the Group3 subFormat, the previous z.decodeRow - // call (or z.startDecode call) has already consumed one of the - // 6 consecutive EOL's. The next EOL is actually the second of - // 6, in the middle, and we shouldn't align at that point. - if z.align && (z.subFormat == Group4) { - z.br.alignToByteBoundary() - } - - if err := z.decodeEOL(); err == errMissingEOL { - // No-op. It's another row of pixel data. - } else if err != nil { - z.readErr = err - break - } else { - if z.readErr = z.finishDecode(true); z.readErr != nil { - break - } - z.readErr = io.EOF - break - } - - } else if z.rowsRemaining == 0 { - // We do know the image height in advance, and we have already - // decoded exactly that many rows. - if z.readErr = z.finishDecode(false); z.readErr != nil { - break - } - z.readErr = io.EOF - break - - } else { - z.rowsRemaining-- - } - - if z.readErr = z.decodeRow(z.rowsRemaining == 0); z.readErr != nil { - break - } - } - - // Pack from z.curr (1 byte per pixel) to p (1 bit per pixel). - packD, packS := highBits(p, z.curr[z.ri:], z.invert) - p = p[packD:] - z.ri += packS - - // Prepare to decode the next row, if necessary. - if z.ri == len(z.curr) { - z.ri, z.curr, z.prev = 0, z.prev, z.curr - z.atStartOfRow = true - } - } - - n := len(originalP) - len(p) - if z.invert { - invertBytes(originalP[:n]) - } - return n, z.readErr -} - -func (z *reader) penColor() byte { - if z.penColorIsWhite { - return 0xFF - } - return 0x00 -} - -func (z *reader) startDecode() error { - switch z.subFormat { - case Group3: - if err := z.decodeEOL(); err != nil { - return err - } - - case Group4: - // No-op. - - default: - return errUnsupportedSubFormat - } - - z.seenStartOfImage = true - return nil -} - -func (z *reader) finishDecode(alreadySeenEOL bool) error { - numberOfEOLs := 0 - switch z.subFormat { - case Group3: - if z.truncated { - return nil - } - // The stream ends with a RTC (Return To Control) of 6 consecutive - // EOL's, but we should have already just seen an EOL, either in - // z.startDecode (for a zero-height image) or in z.decodeRow. - numberOfEOLs = 5 - - case Group4: - autoDetectHeight := z.rowsRemaining < 0 - if autoDetectHeight { - // Aligning to a byte boundary was already handled by reader.Read. - } else if z.align { - z.br.alignToByteBoundary() - } - // The stream ends with two EOL's. If the first one is missing, and we - // had an explicit image height, we just assume that the trailing two - // EOL's were truncated and return a nil error. - if err := z.decodeEOL(); err != nil { - if (err == errMissingEOL) && !autoDetectHeight { - z.truncated = true - return nil - } - return err - } - numberOfEOLs = 1 - - default: - return errUnsupportedSubFormat - } - - if alreadySeenEOL { - numberOfEOLs-- - } - for ; numberOfEOLs > 0; numberOfEOLs-- { - if err := z.decodeEOL(); err != nil { - return err - } - } - return nil -} - -func (z *reader) decodeEOL() error { - return decodeEOL(&z.br) -} - -func (z *reader) decodeRow(finalRow bool) error { - z.wi = 0 - z.atStartOfRow = true - z.penColorIsWhite = true - - if z.align { - z.br.alignToByteBoundary() - } - - switch z.subFormat { - case Group3: - for ; z.wi < len(z.curr); z.atStartOfRow = false { - if err := z.decodeRun(); err != nil { - return err - } - } - err := z.decodeEOL() - if finalRow && (err == errMissingEOL) { - z.truncated = true - return nil - } - return err - - case Group4: - for ; z.wi < len(z.curr); z.atStartOfRow = false { - mode, err := decode(&z.br, modeDecodeTable[:]) - if err != nil { - return err - } - rm := readerMode{} - if mode < uint32(len(readerModes)) { - rm = readerModes[mode] - } - if rm.function == nil { - return errInvalidMode - } - if err := rm.function(z, rm.arg); err != nil { - return err - } - } - return nil - } - - return errUnsupportedSubFormat -} - -func (z *reader) decodeRun() error { - table := blackDecodeTable[:] - if z.penColorIsWhite { - table = whiteDecodeTable[:] - } - - total := 0 - for { - n, err := decode(&z.br, table) - if err != nil { - return err - } - if n > maxWidth { - panic("unreachable") - } - total += int(n) - if total > maxWidth { - return errRunLengthTooLong - } - // Anything 0x3F or below is a terminal code. - if n <= 0x3F { - break - } - } - - if total > (len(z.curr) - z.wi) { - return errRunLengthOverflowsWidth - } - dst := z.curr[z.wi : z.wi+total] - penColor := z.penColor() - for i := range dst { - dst[i] = penColor - } - z.wi += total - z.penColorIsWhite = !z.penColorIsWhite - - return nil -} - -// The various modes' semantics are based on determining a row of pixels' -// "changing elements": those pixels whose color differs from the one on its -// immediate left. -// -// The row above the first row is implicitly all white. Similarly, the column -// to the left of the first column is implicitly all white. -// -// For example, here's Figure 1 in "ITU-T Recommendation T.6", where the -// current and previous rows contain black (B) and white (w) pixels. The a? -// indexes point into curr, the b? indexes point into prev. -// -// b1 b2 -// v v -// prev: BBBBBwwwwwBBBwwwww -// curr: BBBwwwwwBBBBBBwwww -// ^ ^ ^ -// a0 a1 a2 -// -// a0 is the "reference element" or current decoder position, roughly -// equivalent to what this implementation calls reader.wi. -// -// a1 is the next changing element to the right of a0, on the "coding line" -// (the current row). -// -// a2 is the next changing element to the right of a1, again on curr. -// -// b1 is the first changing element on the "reference line" (the previous row) -// to the right of a0 and of opposite color to a0. -// -// b2 is the next changing element to the right of b1, again on prev. -// -// The various modes calculate a1 (and a2, for modeH): -// - modePass calculates that a1 is at or to the right of b2. -// - modeH calculates a1 and a2 without considering b1 or b2. -// - modeV* calculates a1 to be b1 plus an adjustment (between -3 and +3). - -const ( - findB1 = false - findB2 = true -) - -// findB finds either the b1 or b2 value. -func (z *reader) findB(whichB bool) int { - // The initial row is a special case. The previous row is implicitly all - // white, so that there are no changing pixel elements. We return b1 or b2 - // to be at the end of the row. - if len(z.prev) != len(z.curr) { - return len(z.curr) - } - - i := z.wi - - if z.atStartOfRow { - // a0 is implicitly at -1, on a white pixel. b1 is the first black - // pixel in the previous row. b2 is the first white pixel after that. - for ; (i < len(z.prev)) && (z.prev[i] == 0xFF); i++ { - } - if whichB == findB2 { - for ; (i < len(z.prev)) && (z.prev[i] == 0x00); i++ { - } - } - return i - } - - // As per figure 1 above, assume that the current pen color is white. - // First, walk past every contiguous black pixel in prev, starting at a0. - oppositeColor := ^z.penColor() - for ; (i < len(z.prev)) && (z.prev[i] == oppositeColor); i++ { - } - - // Then walk past every contiguous white pixel. - penColor := ^oppositeColor - for ; (i < len(z.prev)) && (z.prev[i] == penColor); i++ { - } - - // We're now at a black pixel (or at the end of the row). That's b1. - if whichB == findB2 { - // If we're looking for b2, walk past every contiguous black pixel - // again. - oppositeColor := ^penColor - for ; (i < len(z.prev)) && (z.prev[i] == oppositeColor); i++ { - } - } - - return i -} - -type readerMode struct { - function func(z *reader, arg int) error - arg int -} - -var readerModes = [...]readerMode{ - modePass: {function: readerModePass}, - modeH: {function: readerModeH}, - modeV0: {function: readerModeV, arg: +0}, - modeVR1: {function: readerModeV, arg: +1}, - modeVR2: {function: readerModeV, arg: +2}, - modeVR3: {function: readerModeV, arg: +3}, - modeVL1: {function: readerModeV, arg: -1}, - modeVL2: {function: readerModeV, arg: -2}, - modeVL3: {function: readerModeV, arg: -3}, - modeExt: {function: readerModeExt}, -} - -func readerModePass(z *reader, arg int) error { - b2 := z.findB(findB2) - if (b2 < z.wi) || (len(z.curr) < b2) { - return errInvalidOffset - } - dst := z.curr[z.wi:b2] - penColor := z.penColor() - for i := range dst { - dst[i] = penColor - } - z.wi = b2 - return nil -} - -func readerModeH(z *reader, arg int) error { - // The first iteration finds a1. The second finds a2. - for i := 0; i < 2; i++ { - if err := z.decodeRun(); err != nil { - return err - } - } - return nil -} - -func readerModeV(z *reader, arg int) error { - a1 := z.findB(findB1) + arg - if (a1 < z.wi) || (len(z.curr) < a1) { - return errInvalidOffset - } - dst := z.curr[z.wi:a1] - penColor := z.penColor() - for i := range dst { - dst[i] = penColor - } - z.wi = a1 - z.penColorIsWhite = !z.penColorIsWhite - return nil -} - -func readerModeExt(z *reader, arg int) error { - return errUnsupportedMode -} - -// DecodeIntoGray decodes the CCITT-formatted data in r into dst. -// -// It returns an error if dst's width and height don't match the implied width -// and height of CCITT-formatted data. -func DecodeIntoGray(dst *image.Gray, r io.Reader, order Order, sf SubFormat, opts *Options) error { - bounds := dst.Bounds() - if (bounds.Dx() < 0) || (bounds.Dy() < 0) { - return errInvalidBounds - } - if bounds.Dx() > maxWidth { - return errUnsupportedWidth - } - - z := reader{ - br: bitReader{r: r, order: order}, - subFormat: sf, - align: (opts != nil) && opts.Align, - invert: (opts != nil) && opts.Invert, - width: bounds.Dx(), - } - if err := z.startDecode(); err != nil { - return err - } - - width := bounds.Dx() - for y := bounds.Min.Y; y < bounds.Max.Y; y++ { - p := (y - bounds.Min.Y) * dst.Stride - z.curr = dst.Pix[p : p+width] - if err := z.decodeRow(y+1 == bounds.Max.Y); err != nil { - return err - } - z.curr, z.prev = nil, z.curr - } - - if err := z.finishDecode(false); err != nil { - return err - } - - if z.invert { - for y := bounds.Min.Y; y < bounds.Max.Y; y++ { - p := (y - bounds.Min.Y) * dst.Stride - invertBytes(dst.Pix[p : p+width]) - } - } - - return nil -} - -// NewReader returns an io.Reader that decodes the CCITT-formatted data in r. -// The resultant byte stream is one bit per pixel (MSB first), with 1 meaning -// white and 0 meaning black. Each row in the result is byte-aligned. -// -// A negative height, such as passing AutoDetectHeight, means that the image -// height is not known in advance. A negative width is invalid. -func NewReader(r io.Reader, order Order, sf SubFormat, width int, height int, opts *Options) io.Reader { - readErr := error(nil) - if width < 0 { - readErr = errInvalidBounds - } else if width > maxWidth { - readErr = errUnsupportedWidth - } - - return &reader{ - br: bitReader{r: r, order: order}, - subFormat: sf, - align: (opts != nil) && opts.Align, - invert: (opts != nil) && opts.Invert, - width: width, - rowsRemaining: height, - readErr: readErr, - } -} diff --git a/vendor/golang.org/x/image/ccitt/table.go b/vendor/golang.org/x/image/ccitt/table.go deleted file mode 100644 index 8b3794b..0000000 --- a/vendor/golang.org/x/image/ccitt/table.go +++ /dev/null @@ -1,972 +0,0 @@ -// generated by "go run gen.go". DO NOT EDIT. - -package ccitt - -// Each decodeTable is represented by an array of [2]int16's: a binary tree. -// Each array element (other than element 0, which means invalid) is a branch -// node in that tree. The root node is always element 1 (the second element). -// -// To walk the tree, look at the next bit in the bit stream, using it to select -// the first or second element of the [2]int16. If that int16 is 0, we have an -// invalid code. If it is positive, go to that branch node. If it is negative, -// then we have a leaf node, whose value is the bitwise complement (the ^ -// operator) of that int16. -// -// Comments above each decodeTable also show the same structure visually. The -// "b123" lines show the 123'rd branch node. The "=XXXXX" lines show an invalid -// code. The "=v1234" lines show a leaf node with value 1234. When reading the -// bit stream, a 0 or 1 bit means to go up or down, as you move left to right. -// -// For example, in modeDecodeTable, branch node b005 is three steps up from the -// root node, meaning that we have already seen "000". If the next bit is "0" -// then we move to branch node b006. Otherwise, the next bit is "1", and we -// move to the leaf node v0000 (also known as the modePass constant). Indeed, -// the bits that encode modePass are "0001". -// -// Tables 1, 2 and 3 come from the "ITU-T Recommendation T.6: FACSIMILE CODING -// SCHEMES AND CODING CONTROL FUNCTIONS FOR GROUP 4 FACSIMILE APPARATUS" -// specification: -// -// https://www.itu.int/rec/dologin_pub.asp?lang=e&id=T-REC-T.6-198811-I!!PDF-E&type=items - -// modeDecodeTable represents Table 1 and the End-of-Line code. -// -// +=XXXXX -// b009 +-+ -// | +=v0009 -// b007 +-+ -// | | +=v0008 -// b010 | +-+ -// | +=v0005 -// b006 +-+ -// | | +=v0007 -// b008 | +-+ -// | +=v0004 -// b005 +-+ -// | +=v0000 -// b003 +-+ -// | +=v0001 -// b002 +-+ -// | | +=v0006 -// b004 | +-+ -// | +=v0003 -// b001 +-+ -// +=v0002 -var modeDecodeTable = [...][2]int16{ - 0: {0, 0}, - 1: {2, ^2}, - 2: {3, 4}, - 3: {5, ^1}, - 4: {^6, ^3}, - 5: {6, ^0}, - 6: {7, 8}, - 7: {9, 10}, - 8: {^7, ^4}, - 9: {0, ^9}, - 10: {^8, ^5}, -} - -// whiteDecodeTable represents Tables 2 and 3 for a white run. -// -// +=XXXXX -// b059 +-+ -// | | +=v1792 -// b096 | | +-+ -// | | | | +=v1984 -// b100 | | | +-+ -// | | | +=v2048 -// b094 | | +-+ -// | | | | +=v2112 -// b101 | | | | +-+ -// | | | | | +=v2176 -// b097 | | | +-+ -// | | | | +=v2240 -// b102 | | | +-+ -// | | | +=v2304 -// b085 | +-+ -// | | +=v1856 -// b098 | | +-+ -// | | | +=v1920 -// b095 | +-+ -// | | +=v2368 -// b103 | | +-+ -// | | | +=v2432 -// b099 | +-+ -// | | +=v2496 -// b104 | +-+ -// | +=v2560 -// b040 +-+ -// | | +=v0029 -// b060 | +-+ -// | +=v0030 -// b026 +-+ -// | | +=v0045 -// b061 | | +-+ -// | | | +=v0046 -// b041 | +-+ -// | +=v0022 -// b016 +-+ -// | | +=v0023 -// b042 | | +-+ -// | | | | +=v0047 -// b062 | | | +-+ -// | | | +=v0048 -// b027 | +-+ -// | +=v0013 -// b008 +-+ -// | | +=v0020 -// b043 | | +-+ -// | | | | +=v0033 -// b063 | | | +-+ -// | | | +=v0034 -// b028 | | +-+ -// | | | | +=v0035 -// b064 | | | | +-+ -// | | | | | +=v0036 -// b044 | | | +-+ -// | | | | +=v0037 -// b065 | | | +-+ -// | | | +=v0038 -// b017 | +-+ -// | | +=v0019 -// b045 | | +-+ -// | | | | +=v0031 -// b066 | | | +-+ -// | | | +=v0032 -// b029 | +-+ -// | +=v0001 -// b004 +-+ -// | | +=v0012 -// b030 | | +-+ -// | | | | +=v0053 -// b067 | | | | +-+ -// | | | | | +=v0054 -// b046 | | | +-+ -// | | | +=v0026 -// b018 | | +-+ -// | | | | +=v0039 -// b068 | | | | +-+ -// | | | | | +=v0040 -// b047 | | | | +-+ -// | | | | | | +=v0041 -// b069 | | | | | +-+ -// | | | | | +=v0042 -// b031 | | | +-+ -// | | | | +=v0043 -// b070 | | | | +-+ -// | | | | | +=v0044 -// b048 | | | +-+ -// | | | +=v0021 -// b009 | +-+ -// | | +=v0028 -// b049 | | +-+ -// | | | | +=v0061 -// b071 | | | +-+ -// | | | +=v0062 -// b032 | | +-+ -// | | | | +=v0063 -// b072 | | | | +-+ -// | | | | | +=v0000 -// b050 | | | +-+ -// | | | | +=v0320 -// b073 | | | +-+ -// | | | +=v0384 -// b019 | +-+ -// | +=v0010 -// b002 +-+ -// | | +=v0011 -// b020 | | +-+ -// | | | | +=v0027 -// b051 | | | | +-+ -// | | | | | | +=v0059 -// b074 | | | | | +-+ -// | | | | | +=v0060 -// b033 | | | +-+ -// | | | | +=v1472 -// b086 | | | | +-+ -// | | | | | +=v1536 -// b075 | | | | +-+ -// | | | | | | +=v1600 -// b087 | | | | | +-+ -// | | | | | +=v1728 -// b052 | | | +-+ -// | | | +=v0018 -// b010 | | +-+ -// | | | | +=v0024 -// b053 | | | | +-+ -// | | | | | | +=v0049 -// b076 | | | | | +-+ -// | | | | | +=v0050 -// b034 | | | | +-+ -// | | | | | | +=v0051 -// b077 | | | | | | +-+ -// | | | | | | | +=v0052 -// b054 | | | | | +-+ -// | | | | | +=v0025 -// b021 | | | +-+ -// | | | | +=v0055 -// b078 | | | | +-+ -// | | | | | +=v0056 -// b055 | | | | +-+ -// | | | | | | +=v0057 -// b079 | | | | | +-+ -// | | | | | +=v0058 -// b035 | | | +-+ -// | | | +=v0192 -// b005 | +-+ -// | | +=v1664 -// b036 | | +-+ -// | | | | +=v0448 -// b080 | | | | +-+ -// | | | | | +=v0512 -// b056 | | | +-+ -// | | | | +=v0704 -// b088 | | | | +-+ -// | | | | | +=v0768 -// b081 | | | +-+ -// | | | +=v0640 -// b022 | | +-+ -// | | | | +=v0576 -// b082 | | | | +-+ -// | | | | | | +=v0832 -// b089 | | | | | +-+ -// | | | | | +=v0896 -// b057 | | | | +-+ -// | | | | | | +=v0960 -// b090 | | | | | | +-+ -// | | | | | | | +=v1024 -// b083 | | | | | +-+ -// | | | | | | +=v1088 -// b091 | | | | | +-+ -// | | | | | +=v1152 -// b037 | | | +-+ -// | | | | +=v1216 -// b092 | | | | +-+ -// | | | | | +=v1280 -// b084 | | | | +-+ -// | | | | | | +=v1344 -// b093 | | | | | +-+ -// | | | | | +=v1408 -// b058 | | | +-+ -// | | | +=v0256 -// b011 | +-+ -// | +=v0002 -// b001 +-+ -// | +=v0003 -// b012 | +-+ -// | | | +=v0128 -// b023 | | +-+ -// | | +=v0008 -// b006 | +-+ -// | | | +=v0009 -// b024 | | | +-+ -// | | | | | +=v0016 -// b038 | | | | +-+ -// | | | | +=v0017 -// b013 | | +-+ -// | | +=v0004 -// b003 +-+ -// | +=v0005 -// b014 | +-+ -// | | | +=v0014 -// b039 | | | +-+ -// | | | | +=v0015 -// b025 | | +-+ -// | | +=v0064 -// b007 +-+ -// | +=v0006 -// b015 +-+ -// +=v0007 -var whiteDecodeTable = [...][2]int16{ - 0: {0, 0}, - 1: {2, 3}, - 2: {4, 5}, - 3: {6, 7}, - 4: {8, 9}, - 5: {10, 11}, - 6: {12, 13}, - 7: {14, 15}, - 8: {16, 17}, - 9: {18, 19}, - 10: {20, 21}, - 11: {22, ^2}, - 12: {^3, 23}, - 13: {24, ^4}, - 14: {^5, 25}, - 15: {^6, ^7}, - 16: {26, 27}, - 17: {28, 29}, - 18: {30, 31}, - 19: {32, ^10}, - 20: {^11, 33}, - 21: {34, 35}, - 22: {36, 37}, - 23: {^128, ^8}, - 24: {^9, 38}, - 25: {39, ^64}, - 26: {40, 41}, - 27: {42, ^13}, - 28: {43, 44}, - 29: {45, ^1}, - 30: {^12, 46}, - 31: {47, 48}, - 32: {49, 50}, - 33: {51, 52}, - 34: {53, 54}, - 35: {55, ^192}, - 36: {^1664, 56}, - 37: {57, 58}, - 38: {^16, ^17}, - 39: {^14, ^15}, - 40: {59, 60}, - 41: {61, ^22}, - 42: {^23, 62}, - 43: {^20, 63}, - 44: {64, 65}, - 45: {^19, 66}, - 46: {67, ^26}, - 47: {68, 69}, - 48: {70, ^21}, - 49: {^28, 71}, - 50: {72, 73}, - 51: {^27, 74}, - 52: {75, ^18}, - 53: {^24, 76}, - 54: {77, ^25}, - 55: {78, 79}, - 56: {80, 81}, - 57: {82, 83}, - 58: {84, ^256}, - 59: {0, 85}, - 60: {^29, ^30}, - 61: {^45, ^46}, - 62: {^47, ^48}, - 63: {^33, ^34}, - 64: {^35, ^36}, - 65: {^37, ^38}, - 66: {^31, ^32}, - 67: {^53, ^54}, - 68: {^39, ^40}, - 69: {^41, ^42}, - 70: {^43, ^44}, - 71: {^61, ^62}, - 72: {^63, ^0}, - 73: {^320, ^384}, - 74: {^59, ^60}, - 75: {86, 87}, - 76: {^49, ^50}, - 77: {^51, ^52}, - 78: {^55, ^56}, - 79: {^57, ^58}, - 80: {^448, ^512}, - 81: {88, ^640}, - 82: {^576, 89}, - 83: {90, 91}, - 84: {92, 93}, - 85: {94, 95}, - 86: {^1472, ^1536}, - 87: {^1600, ^1728}, - 88: {^704, ^768}, - 89: {^832, ^896}, - 90: {^960, ^1024}, - 91: {^1088, ^1152}, - 92: {^1216, ^1280}, - 93: {^1344, ^1408}, - 94: {96, 97}, - 95: {98, 99}, - 96: {^1792, 100}, - 97: {101, 102}, - 98: {^1856, ^1920}, - 99: {103, 104}, - 100: {^1984, ^2048}, - 101: {^2112, ^2176}, - 102: {^2240, ^2304}, - 103: {^2368, ^2432}, - 104: {^2496, ^2560}, -} - -// blackDecodeTable represents Tables 2 and 3 for a black run. -// -// +=XXXXX -// b017 +-+ -// | | +=v1792 -// b042 | | +-+ -// | | | | +=v1984 -// b063 | | | +-+ -// | | | +=v2048 -// b029 | | +-+ -// | | | | +=v2112 -// b064 | | | | +-+ -// | | | | | +=v2176 -// b043 | | | +-+ -// | | | | +=v2240 -// b065 | | | +-+ -// | | | +=v2304 -// b022 | +-+ -// | | +=v1856 -// b044 | | +-+ -// | | | +=v1920 -// b030 | +-+ -// | | +=v2368 -// b066 | | +-+ -// | | | +=v2432 -// b045 | +-+ -// | | +=v2496 -// b067 | +-+ -// | +=v2560 -// b013 +-+ -// | | +=v0018 -// b031 | | +-+ -// | | | | +=v0052 -// b068 | | | | +-+ -// | | | | | | +=v0640 -// b095 | | | | | +-+ -// | | | | | +=v0704 -// b046 | | | +-+ -// | | | | +=v0768 -// b096 | | | | +-+ -// | | | | | +=v0832 -// b069 | | | +-+ -// | | | +=v0055 -// b023 | | +-+ -// | | | | +=v0056 -// b070 | | | | +-+ -// | | | | | | +=v1280 -// b097 | | | | | +-+ -// | | | | | +=v1344 -// b047 | | | | +-+ -// | | | | | | +=v1408 -// b098 | | | | | | +-+ -// | | | | | | | +=v1472 -// b071 | | | | | +-+ -// | | | | | +=v0059 -// b032 | | | +-+ -// | | | | +=v0060 -// b072 | | | | +-+ -// | | | | | | +=v1536 -// b099 | | | | | +-+ -// | | | | | +=v1600 -// b048 | | | +-+ -// | | | +=v0024 -// b018 | +-+ -// | | +=v0025 -// b049 | | +-+ -// | | | | +=v1664 -// b100 | | | | +-+ -// | | | | | +=v1728 -// b073 | | | +-+ -// | | | +=v0320 -// b033 | | +-+ -// | | | | +=v0384 -// b074 | | | | +-+ -// | | | | | +=v0448 -// b050 | | | +-+ -// | | | | +=v0512 -// b101 | | | | +-+ -// | | | | | +=v0576 -// b075 | | | +-+ -// | | | +=v0053 -// b024 | +-+ -// | | +=v0054 -// b076 | | +-+ -// | | | | +=v0896 -// b102 | | | +-+ -// | | | +=v0960 -// b051 | | +-+ -// | | | | +=v1024 -// b103 | | | | +-+ -// | | | | | +=v1088 -// b077 | | | +-+ -// | | | | +=v1152 -// b104 | | | +-+ -// | | | +=v1216 -// b034 | +-+ -// | +=v0064 -// b010 +-+ -// | | +=v0013 -// b019 | | +-+ -// | | | | +=v0023 -// b052 | | | | +-+ -// | | | | | | +=v0050 -// b078 | | | | | +-+ -// | | | | | +=v0051 -// b035 | | | | +-+ -// | | | | | | +=v0044 -// b079 | | | | | | +-+ -// | | | | | | | +=v0045 -// b053 | | | | | +-+ -// | | | | | | +=v0046 -// b080 | | | | | +-+ -// | | | | | +=v0047 -// b025 | | | +-+ -// | | | | +=v0057 -// b081 | | | | +-+ -// | | | | | +=v0058 -// b054 | | | | +-+ -// | | | | | | +=v0061 -// b082 | | | | | +-+ -// | | | | | +=v0256 -// b036 | | | +-+ -// | | | +=v0016 -// b014 | +-+ -// | | +=v0017 -// b037 | | +-+ -// | | | | +=v0048 -// b083 | | | | +-+ -// | | | | | +=v0049 -// b055 | | | +-+ -// | | | | +=v0062 -// b084 | | | +-+ -// | | | +=v0063 -// b026 | | +-+ -// | | | | +=v0030 -// b085 | | | | +-+ -// | | | | | +=v0031 -// b056 | | | | +-+ -// | | | | | | +=v0032 -// b086 | | | | | +-+ -// | | | | | +=v0033 -// b038 | | | +-+ -// | | | | +=v0040 -// b087 | | | | +-+ -// | | | | | +=v0041 -// b057 | | | +-+ -// | | | +=v0022 -// b020 | +-+ -// | +=v0014 -// b008 +-+ -// | | +=v0010 -// b015 | | +-+ -// | | | +=v0011 -// b011 | +-+ -// | | +=v0015 -// b027 | | +-+ -// | | | | +=v0128 -// b088 | | | | +-+ -// | | | | | +=v0192 -// b058 | | | | +-+ -// | | | | | | +=v0026 -// b089 | | | | | +-+ -// | | | | | +=v0027 -// b039 | | | +-+ -// | | | | +=v0028 -// b090 | | | | +-+ -// | | | | | +=v0029 -// b059 | | | +-+ -// | | | +=v0019 -// b021 | | +-+ -// | | | | +=v0020 -// b060 | | | | +-+ -// | | | | | | +=v0034 -// b091 | | | | | +-+ -// | | | | | +=v0035 -// b040 | | | | +-+ -// | | | | | | +=v0036 -// b092 | | | | | | +-+ -// | | | | | | | +=v0037 -// b061 | | | | | +-+ -// | | | | | | +=v0038 -// b093 | | | | | +-+ -// | | | | | +=v0039 -// b028 | | | +-+ -// | | | | +=v0021 -// b062 | | | | +-+ -// | | | | | | +=v0042 -// b094 | | | | | +-+ -// | | | | | +=v0043 -// b041 | | | +-+ -// | | | +=v0000 -// b016 | +-+ -// | +=v0012 -// b006 +-+ -// | | +=v0009 -// b012 | | +-+ -// | | | +=v0008 -// b009 | +-+ -// | +=v0007 -// b004 +-+ -// | | +=v0006 -// b007 | +-+ -// | +=v0005 -// b002 +-+ -// | | +=v0001 -// b005 | +-+ -// | +=v0004 -// b001 +-+ -// | +=v0003 -// b003 +-+ -// +=v0002 -var blackDecodeTable = [...][2]int16{ - 0: {0, 0}, - 1: {2, 3}, - 2: {4, 5}, - 3: {^3, ^2}, - 4: {6, 7}, - 5: {^1, ^4}, - 6: {8, 9}, - 7: {^6, ^5}, - 8: {10, 11}, - 9: {12, ^7}, - 10: {13, 14}, - 11: {15, 16}, - 12: {^9, ^8}, - 13: {17, 18}, - 14: {19, 20}, - 15: {^10, ^11}, - 16: {21, ^12}, - 17: {0, 22}, - 18: {23, 24}, - 19: {^13, 25}, - 20: {26, ^14}, - 21: {27, 28}, - 22: {29, 30}, - 23: {31, 32}, - 24: {33, 34}, - 25: {35, 36}, - 26: {37, 38}, - 27: {^15, 39}, - 28: {40, 41}, - 29: {42, 43}, - 30: {44, 45}, - 31: {^18, 46}, - 32: {47, 48}, - 33: {49, 50}, - 34: {51, ^64}, - 35: {52, 53}, - 36: {54, ^16}, - 37: {^17, 55}, - 38: {56, 57}, - 39: {58, 59}, - 40: {60, 61}, - 41: {62, ^0}, - 42: {^1792, 63}, - 43: {64, 65}, - 44: {^1856, ^1920}, - 45: {66, 67}, - 46: {68, 69}, - 47: {70, 71}, - 48: {72, ^24}, - 49: {^25, 73}, - 50: {74, 75}, - 51: {76, 77}, - 52: {^23, 78}, - 53: {79, 80}, - 54: {81, 82}, - 55: {83, 84}, - 56: {85, 86}, - 57: {87, ^22}, - 58: {88, 89}, - 59: {90, ^19}, - 60: {^20, 91}, - 61: {92, 93}, - 62: {^21, 94}, - 63: {^1984, ^2048}, - 64: {^2112, ^2176}, - 65: {^2240, ^2304}, - 66: {^2368, ^2432}, - 67: {^2496, ^2560}, - 68: {^52, 95}, - 69: {96, ^55}, - 70: {^56, 97}, - 71: {98, ^59}, - 72: {^60, 99}, - 73: {100, ^320}, - 74: {^384, ^448}, - 75: {101, ^53}, - 76: {^54, 102}, - 77: {103, 104}, - 78: {^50, ^51}, - 79: {^44, ^45}, - 80: {^46, ^47}, - 81: {^57, ^58}, - 82: {^61, ^256}, - 83: {^48, ^49}, - 84: {^62, ^63}, - 85: {^30, ^31}, - 86: {^32, ^33}, - 87: {^40, ^41}, - 88: {^128, ^192}, - 89: {^26, ^27}, - 90: {^28, ^29}, - 91: {^34, ^35}, - 92: {^36, ^37}, - 93: {^38, ^39}, - 94: {^42, ^43}, - 95: {^640, ^704}, - 96: {^768, ^832}, - 97: {^1280, ^1344}, - 98: {^1408, ^1472}, - 99: {^1536, ^1600}, - 100: {^1664, ^1728}, - 101: {^512, ^576}, - 102: {^896, ^960}, - 103: {^1024, ^1088}, - 104: {^1152, ^1216}, -} - -const maxCodeLength = 13 - -// Each encodeTable is represented by an array of bitStrings. - -// bitString is a pair of uint32 values representing a bit code. -// The nBits low bits of bits make up the actual bit code. -// Eg. bitString{0x0004, 8} represents the bitcode "00000100". -type bitString struct { - bits uint32 - nBits uint32 -} - -// modeEncodeTable represents Table 1 and the End-of-Line code. -var modeEncodeTable = [...]bitString{ - 0: {0x0001, 4}, // "0001" - 1: {0x0001, 3}, // "001" - 2: {0x0001, 1}, // "1" - 3: {0x0003, 3}, // "011" - 4: {0x0003, 6}, // "000011" - 5: {0x0003, 7}, // "0000011" - 6: {0x0002, 3}, // "010" - 7: {0x0002, 6}, // "000010" - 8: {0x0002, 7}, // "0000010" - 9: {0x0001, 7}, // "0000001" -} - -// whiteEncodeTable2 represents Table 2 for a white run. -var whiteEncodeTable2 = [...]bitString{ - 0: {0x0035, 8}, // "00110101" - 1: {0x0007, 6}, // "000111" - 2: {0x0007, 4}, // "0111" - 3: {0x0008, 4}, // "1000" - 4: {0x000b, 4}, // "1011" - 5: {0x000c, 4}, // "1100" - 6: {0x000e, 4}, // "1110" - 7: {0x000f, 4}, // "1111" - 8: {0x0013, 5}, // "10011" - 9: {0x0014, 5}, // "10100" - 10: {0x0007, 5}, // "00111" - 11: {0x0008, 5}, // "01000" - 12: {0x0008, 6}, // "001000" - 13: {0x0003, 6}, // "000011" - 14: {0x0034, 6}, // "110100" - 15: {0x0035, 6}, // "110101" - 16: {0x002a, 6}, // "101010" - 17: {0x002b, 6}, // "101011" - 18: {0x0027, 7}, // "0100111" - 19: {0x000c, 7}, // "0001100" - 20: {0x0008, 7}, // "0001000" - 21: {0x0017, 7}, // "0010111" - 22: {0x0003, 7}, // "0000011" - 23: {0x0004, 7}, // "0000100" - 24: {0x0028, 7}, // "0101000" - 25: {0x002b, 7}, // "0101011" - 26: {0x0013, 7}, // "0010011" - 27: {0x0024, 7}, // "0100100" - 28: {0x0018, 7}, // "0011000" - 29: {0x0002, 8}, // "00000010" - 30: {0x0003, 8}, // "00000011" - 31: {0x001a, 8}, // "00011010" - 32: {0x001b, 8}, // "00011011" - 33: {0x0012, 8}, // "00010010" - 34: {0x0013, 8}, // "00010011" - 35: {0x0014, 8}, // "00010100" - 36: {0x0015, 8}, // "00010101" - 37: {0x0016, 8}, // "00010110" - 38: {0x0017, 8}, // "00010111" - 39: {0x0028, 8}, // "00101000" - 40: {0x0029, 8}, // "00101001" - 41: {0x002a, 8}, // "00101010" - 42: {0x002b, 8}, // "00101011" - 43: {0x002c, 8}, // "00101100" - 44: {0x002d, 8}, // "00101101" - 45: {0x0004, 8}, // "00000100" - 46: {0x0005, 8}, // "00000101" - 47: {0x000a, 8}, // "00001010" - 48: {0x000b, 8}, // "00001011" - 49: {0x0052, 8}, // "01010010" - 50: {0x0053, 8}, // "01010011" - 51: {0x0054, 8}, // "01010100" - 52: {0x0055, 8}, // "01010101" - 53: {0x0024, 8}, // "00100100" - 54: {0x0025, 8}, // "00100101" - 55: {0x0058, 8}, // "01011000" - 56: {0x0059, 8}, // "01011001" - 57: {0x005a, 8}, // "01011010" - 58: {0x005b, 8}, // "01011011" - 59: {0x004a, 8}, // "01001010" - 60: {0x004b, 8}, // "01001011" - 61: {0x0032, 8}, // "00110010" - 62: {0x0033, 8}, // "00110011" - 63: {0x0034, 8}, // "00110100" -} - -// whiteEncodeTable3 represents Table 3 for a white run. -var whiteEncodeTable3 = [...]bitString{ - 0: {0x001b, 5}, // "11011" - 1: {0x0012, 5}, // "10010" - 2: {0x0017, 6}, // "010111" - 3: {0x0037, 7}, // "0110111" - 4: {0x0036, 8}, // "00110110" - 5: {0x0037, 8}, // "00110111" - 6: {0x0064, 8}, // "01100100" - 7: {0x0065, 8}, // "01100101" - 8: {0x0068, 8}, // "01101000" - 9: {0x0067, 8}, // "01100111" - 10: {0x00cc, 9}, // "011001100" - 11: {0x00cd, 9}, // "011001101" - 12: {0x00d2, 9}, // "011010010" - 13: {0x00d3, 9}, // "011010011" - 14: {0x00d4, 9}, // "011010100" - 15: {0x00d5, 9}, // "011010101" - 16: {0x00d6, 9}, // "011010110" - 17: {0x00d7, 9}, // "011010111" - 18: {0x00d8, 9}, // "011011000" - 19: {0x00d9, 9}, // "011011001" - 20: {0x00da, 9}, // "011011010" - 21: {0x00db, 9}, // "011011011" - 22: {0x0098, 9}, // "010011000" - 23: {0x0099, 9}, // "010011001" - 24: {0x009a, 9}, // "010011010" - 25: {0x0018, 6}, // "011000" - 26: {0x009b, 9}, // "010011011" - 27: {0x0008, 11}, // "00000001000" - 28: {0x000c, 11}, // "00000001100" - 29: {0x000d, 11}, // "00000001101" - 30: {0x0012, 12}, // "000000010010" - 31: {0x0013, 12}, // "000000010011" - 32: {0x0014, 12}, // "000000010100" - 33: {0x0015, 12}, // "000000010101" - 34: {0x0016, 12}, // "000000010110" - 35: {0x0017, 12}, // "000000010111" - 36: {0x001c, 12}, // "000000011100" - 37: {0x001d, 12}, // "000000011101" - 38: {0x001e, 12}, // "000000011110" - 39: {0x001f, 12}, // "000000011111" -} - -// blackEncodeTable2 represents Table 2 for a black run. -var blackEncodeTable2 = [...]bitString{ - 0: {0x0037, 10}, // "0000110111" - 1: {0x0002, 3}, // "010" - 2: {0x0003, 2}, // "11" - 3: {0x0002, 2}, // "10" - 4: {0x0003, 3}, // "011" - 5: {0x0003, 4}, // "0011" - 6: {0x0002, 4}, // "0010" - 7: {0x0003, 5}, // "00011" - 8: {0x0005, 6}, // "000101" - 9: {0x0004, 6}, // "000100" - 10: {0x0004, 7}, // "0000100" - 11: {0x0005, 7}, // "0000101" - 12: {0x0007, 7}, // "0000111" - 13: {0x0004, 8}, // "00000100" - 14: {0x0007, 8}, // "00000111" - 15: {0x0018, 9}, // "000011000" - 16: {0x0017, 10}, // "0000010111" - 17: {0x0018, 10}, // "0000011000" - 18: {0x0008, 10}, // "0000001000" - 19: {0x0067, 11}, // "00001100111" - 20: {0x0068, 11}, // "00001101000" - 21: {0x006c, 11}, // "00001101100" - 22: {0x0037, 11}, // "00000110111" - 23: {0x0028, 11}, // "00000101000" - 24: {0x0017, 11}, // "00000010111" - 25: {0x0018, 11}, // "00000011000" - 26: {0x00ca, 12}, // "000011001010" - 27: {0x00cb, 12}, // "000011001011" - 28: {0x00cc, 12}, // "000011001100" - 29: {0x00cd, 12}, // "000011001101" - 30: {0x0068, 12}, // "000001101000" - 31: {0x0069, 12}, // "000001101001" - 32: {0x006a, 12}, // "000001101010" - 33: {0x006b, 12}, // "000001101011" - 34: {0x00d2, 12}, // "000011010010" - 35: {0x00d3, 12}, // "000011010011" - 36: {0x00d4, 12}, // "000011010100" - 37: {0x00d5, 12}, // "000011010101" - 38: {0x00d6, 12}, // "000011010110" - 39: {0x00d7, 12}, // "000011010111" - 40: {0x006c, 12}, // "000001101100" - 41: {0x006d, 12}, // "000001101101" - 42: {0x00da, 12}, // "000011011010" - 43: {0x00db, 12}, // "000011011011" - 44: {0x0054, 12}, // "000001010100" - 45: {0x0055, 12}, // "000001010101" - 46: {0x0056, 12}, // "000001010110" - 47: {0x0057, 12}, // "000001010111" - 48: {0x0064, 12}, // "000001100100" - 49: {0x0065, 12}, // "000001100101" - 50: {0x0052, 12}, // "000001010010" - 51: {0x0053, 12}, // "000001010011" - 52: {0x0024, 12}, // "000000100100" - 53: {0x0037, 12}, // "000000110111" - 54: {0x0038, 12}, // "000000111000" - 55: {0x0027, 12}, // "000000100111" - 56: {0x0028, 12}, // "000000101000" - 57: {0x0058, 12}, // "000001011000" - 58: {0x0059, 12}, // "000001011001" - 59: {0x002b, 12}, // "000000101011" - 60: {0x002c, 12}, // "000000101100" - 61: {0x005a, 12}, // "000001011010" - 62: {0x0066, 12}, // "000001100110" - 63: {0x0067, 12}, // "000001100111" -} - -// blackEncodeTable3 represents Table 3 for a black run. -var blackEncodeTable3 = [...]bitString{ - 0: {0x000f, 10}, // "0000001111" - 1: {0x00c8, 12}, // "000011001000" - 2: {0x00c9, 12}, // "000011001001" - 3: {0x005b, 12}, // "000001011011" - 4: {0x0033, 12}, // "000000110011" - 5: {0x0034, 12}, // "000000110100" - 6: {0x0035, 12}, // "000000110101" - 7: {0x006c, 13}, // "0000001101100" - 8: {0x006d, 13}, // "0000001101101" - 9: {0x004a, 13}, // "0000001001010" - 10: {0x004b, 13}, // "0000001001011" - 11: {0x004c, 13}, // "0000001001100" - 12: {0x004d, 13}, // "0000001001101" - 13: {0x0072, 13}, // "0000001110010" - 14: {0x0073, 13}, // "0000001110011" - 15: {0x0074, 13}, // "0000001110100" - 16: {0x0075, 13}, // "0000001110101" - 17: {0x0076, 13}, // "0000001110110" - 18: {0x0077, 13}, // "0000001110111" - 19: {0x0052, 13}, // "0000001010010" - 20: {0x0053, 13}, // "0000001010011" - 21: {0x0054, 13}, // "0000001010100" - 22: {0x0055, 13}, // "0000001010101" - 23: {0x005a, 13}, // "0000001011010" - 24: {0x005b, 13}, // "0000001011011" - 25: {0x0064, 13}, // "0000001100100" - 26: {0x0065, 13}, // "0000001100101" - 27: {0x0008, 11}, // "00000001000" - 28: {0x000c, 11}, // "00000001100" - 29: {0x000d, 11}, // "00000001101" - 30: {0x0012, 12}, // "000000010010" - 31: {0x0013, 12}, // "000000010011" - 32: {0x0014, 12}, // "000000010100" - 33: {0x0015, 12}, // "000000010101" - 34: {0x0016, 12}, // "000000010110" - 35: {0x0017, 12}, // "000000010111" - 36: {0x001c, 12}, // "000000011100" - 37: {0x001d, 12}, // "000000011101" - 38: {0x001e, 12}, // "000000011110" - 39: {0x001f, 12}, // "000000011111" -} - -// COPY PASTE table.go BEGIN - -const ( - modePass = iota // Pass - modeH // Horizontal - modeV0 // Vertical-0 - modeVR1 // Vertical-Right-1 - modeVR2 // Vertical-Right-2 - modeVR3 // Vertical-Right-3 - modeVL1 // Vertical-Left-1 - modeVL2 // Vertical-Left-2 - modeVL3 // Vertical-Left-3 - modeExt // Extension -) - -// COPY PASTE table.go END diff --git a/vendor/golang.org/x/image/ccitt/writer.go b/vendor/golang.org/x/image/ccitt/writer.go deleted file mode 100644 index 87130ab..0000000 --- a/vendor/golang.org/x/image/ccitt/writer.go +++ /dev/null @@ -1,102 +0,0 @@ -// Copyright 2019 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -package ccitt - -import ( - "encoding/binary" - "io" -) - -type bitWriter struct { - w io.Writer - - // order is whether to process w's bytes LSB first or MSB first. - order Order - - // The high nBits bits of the bits field hold encoded bits to be written to w. - bits uint64 - nBits uint32 - - // bytes[:bw] holds encoded bytes not yet written to w. - // Overflow protection is ensured by using a multiple of 8 as bytes length. - bw uint32 - bytes [1024]uint8 -} - -// flushBits copies 64 bits from b.bits to b.bytes. If b.bytes is then full, it -// is written to b.w. -func (b *bitWriter) flushBits() error { - binary.BigEndian.PutUint64(b.bytes[b.bw:], b.bits) - b.bits = 0 - b.nBits = 0 - b.bw += 8 - if b.bw < uint32(len(b.bytes)) { - return nil - } - b.bw = 0 - if b.order != MSB { - reverseBitsWithinBytes(b.bytes[:]) - } - _, err := b.w.Write(b.bytes[:]) - return err -} - -// close finalizes a bitcode stream by writing any -// pending bits to bitWriter's underlying io.Writer. -func (b *bitWriter) close() error { - // Write any encoded bits to bytes. - if b.nBits > 0 { - binary.BigEndian.PutUint64(b.bytes[b.bw:], b.bits) - b.bw += (b.nBits + 7) >> 3 - } - - if b.order != MSB { - reverseBitsWithinBytes(b.bytes[:b.bw]) - } - - // Write b.bw bytes to b.w. - _, err := b.w.Write(b.bytes[:b.bw]) - return err -} - -// alignToByteBoundary rounds b.nBits up to a multiple of 8. -// If all 64 bits are used, flush them to bitWriter's bytes. -func (b *bitWriter) alignToByteBoundary() error { - if b.nBits = (b.nBits + 7) &^ 7; b.nBits == 64 { - return b.flushBits() - } - return nil -} - -// writeCode writes a variable length bitcode to b's underlying io.Writer. -func (b *bitWriter) writeCode(bs bitString) error { - bits := bs.bits - nBits := bs.nBits - if 64-b.nBits >= nBits { - // b.bits has sufficient room for storing nBits bits. - b.bits |= uint64(bits) << (64 - nBits - b.nBits) - b.nBits += nBits - if b.nBits == 64 { - return b.flushBits() - } - return nil - } - - // Number of leading bits that fill b.bits. - i := 64 - b.nBits - - // Fill b.bits then flush and write remaining bits. - b.bits |= uint64(bits) >> (nBits - i) - b.nBits = 64 - - if err := b.flushBits(); err != nil { - return err - } - - nBits -= i - b.bits = uint64(bits) << (64 - nBits) - b.nBits = nBits - return nil -} diff --git a/vendor/golang.org/x/image/vp8/decode.go b/vendor/golang.org/x/image/vp8/decode.go new file mode 100644 index 0000000..2aa9fee --- /dev/null +++ b/vendor/golang.org/x/image/vp8/decode.go @@ -0,0 +1,403 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package vp8 implements a decoder for the VP8 lossy image format. +// +// The VP8 specification is RFC 6386. +package vp8 // import "golang.org/x/image/vp8" + +// This file implements the top-level decoding algorithm. + +import ( + "errors" + "image" + "io" +) + +// limitReader wraps an io.Reader to read at most n bytes from it. +type limitReader struct { + r io.Reader + n int +} + +// ReadFull reads exactly len(p) bytes into p. +func (r *limitReader) ReadFull(p []byte) error { + if len(p) > r.n { + return io.ErrUnexpectedEOF + } + n, err := io.ReadFull(r.r, p) + r.n -= n + return err +} + +// FrameHeader is a frame header, as specified in section 9.1. +type FrameHeader struct { + KeyFrame bool + VersionNumber uint8 + ShowFrame bool + FirstPartitionLen uint32 + Width int + Height int + XScale uint8 + YScale uint8 +} + +const ( + nSegment = 4 + nSegmentProb = 3 +) + +// segmentHeader holds segment-related header information. +type segmentHeader struct { + useSegment bool + updateMap bool + relativeDelta bool + quantizer [nSegment]int8 + filterStrength [nSegment]int8 + prob [nSegmentProb]uint8 +} + +const ( + nRefLFDelta = 4 + nModeLFDelta = 4 +) + +// filterHeader holds filter-related header information. +type filterHeader struct { + simple bool + level int8 + sharpness uint8 + useLFDelta bool + refLFDelta [nRefLFDelta]int8 + modeLFDelta [nModeLFDelta]int8 + perSegmentLevel [nSegment]int8 +} + +// mb is the per-macroblock decode state. A decoder maintains mbw+1 of these +// as it is decoding macroblocks left-to-right and top-to-bottom: mbw for the +// macroblocks in the row above, and one for the macroblock to the left. +type mb struct { + // pred is the predictor mode for the 4 bottom or right 4x4 luma regions. + pred [4]uint8 + // nzMask is a mask of 8 bits: 4 for the bottom or right 4x4 luma regions, + // and 2 + 2 for the bottom or right 4x4 chroma regions. A 1 bit indicates + // that region has non-zero coefficients. + nzMask uint8 + // nzY16 is a 0/1 value that is 1 if the macroblock used Y16 prediction and + // had non-zero coefficients. + nzY16 uint8 +} + +// Decoder decodes VP8 bitstreams into frames. Decoding one frame consists of +// calling Init, DecodeFrameHeader and then DecodeFrame in that order. +// A Decoder can be re-used to decode multiple frames. +type Decoder struct { + // r is the input bitsream. + r limitReader + // scratch is a scratch buffer. + scratch [8]byte + // img is the YCbCr image to decode into. + img *image.YCbCr + // mbw and mbh are the number of 16x16 macroblocks wide and high the image is. + mbw, mbh int + // frameHeader is the frame header. When decoding multiple frames, + // frames that aren't key frames will inherit the Width, Height, + // XScale and YScale of the most recent key frame. + frameHeader FrameHeader + // Other headers. + segmentHeader segmentHeader + filterHeader filterHeader + // The image data is divided into a number of independent partitions. + // There is 1 "first partition" and between 1 and 8 "other partitions" + // for coefficient data. + fp partition + op [8]partition + nOP int + // Quantization factors. + quant [nSegment]quant + // DCT/WHT coefficient decoding probabilities. + tokenProb [nPlane][nBand][nContext][nProb]uint8 + useSkipProb bool + skipProb uint8 + // Loop filter parameters. + filterParams [nSegment][2]filterParam + perMBFilterParams []filterParam + + // The eight fields below relate to the current macroblock being decoded. + // + // Segment-based adjustments. + segment int + // Per-macroblock state for the macroblock immediately left of and those + // macroblocks immediately above the current macroblock. + leftMB mb + upMB []mb + // Bitmasks for which 4x4 regions of coeff contain non-zero coefficients. + nzDCMask, nzACMask uint32 + // Predictor modes. + usePredY16 bool // The libwebp C code calls this !is_i4x4_. + predY16 uint8 + predC8 uint8 + predY4 [4][4]uint8 + + // The two fields below form a workspace for reconstructing a macroblock. + // Their specific sizes are documented in reconstruct.go. + coeff [1*16*16 + 2*8*8 + 1*4*4]int16 + ybr [1 + 16 + 1 + 8][32]uint8 +} + +// NewDecoder returns a new Decoder. +func NewDecoder() *Decoder { + return &Decoder{} +} + +// Init initializes the decoder to read at most n bytes from r. +func (d *Decoder) Init(r io.Reader, n int) { + d.r = limitReader{r, n} +} + +// DecodeFrameHeader decodes the frame header. +func (d *Decoder) DecodeFrameHeader() (fh FrameHeader, err error) { + // All frame headers are at least 3 bytes long. + b := d.scratch[:3] + if err = d.r.ReadFull(b); err != nil { + return + } + d.frameHeader.KeyFrame = (b[0] & 1) == 0 + d.frameHeader.VersionNumber = (b[0] >> 1) & 7 + d.frameHeader.ShowFrame = (b[0]>>4)&1 == 1 + d.frameHeader.FirstPartitionLen = uint32(b[0])>>5 | uint32(b[1])<<3 | uint32(b[2])<<11 + if !d.frameHeader.KeyFrame { + return d.frameHeader, nil + } + // Frame headers for key frames are an additional 7 bytes long. + b = d.scratch[:7] + if err = d.r.ReadFull(b); err != nil { + return + } + // Check the magic sync code. + if b[0] != 0x9d || b[1] != 0x01 || b[2] != 0x2a { + err = errors.New("vp8: invalid format") + return + } + d.frameHeader.Width = int(b[4]&0x3f)<<8 | int(b[3]) + d.frameHeader.Height = int(b[6]&0x3f)<<8 | int(b[5]) + d.frameHeader.XScale = b[4] >> 6 + d.frameHeader.YScale = b[6] >> 6 + d.mbw = (d.frameHeader.Width + 0x0f) >> 4 + d.mbh = (d.frameHeader.Height + 0x0f) >> 4 + d.segmentHeader = segmentHeader{ + prob: [3]uint8{0xff, 0xff, 0xff}, + } + d.tokenProb = defaultTokenProb + d.segment = 0 + return d.frameHeader, nil +} + +// ensureImg ensures that d.img is large enough to hold the decoded frame. +func (d *Decoder) ensureImg() { + if d.img != nil { + p0, p1 := d.img.Rect.Min, d.img.Rect.Max + if p0.X == 0 && p0.Y == 0 && p1.X >= 16*d.mbw && p1.Y >= 16*d.mbh { + return + } + } + m := image.NewYCbCr(image.Rect(0, 0, 16*d.mbw, 16*d.mbh), image.YCbCrSubsampleRatio420) + d.img = m.SubImage(image.Rect(0, 0, d.frameHeader.Width, d.frameHeader.Height)).(*image.YCbCr) + d.perMBFilterParams = make([]filterParam, d.mbw*d.mbh) + d.upMB = make([]mb, d.mbw) +} + +// parseSegmentHeader parses the segment header, as specified in section 9.3. +func (d *Decoder) parseSegmentHeader() { + d.segmentHeader.useSegment = d.fp.readBit(uniformProb) + if !d.segmentHeader.useSegment { + d.segmentHeader.updateMap = false + return + } + d.segmentHeader.updateMap = d.fp.readBit(uniformProb) + if d.fp.readBit(uniformProb) { + d.segmentHeader.relativeDelta = !d.fp.readBit(uniformProb) + for i := range d.segmentHeader.quantizer { + d.segmentHeader.quantizer[i] = int8(d.fp.readOptionalInt(uniformProb, 7)) + } + for i := range d.segmentHeader.filterStrength { + d.segmentHeader.filterStrength[i] = int8(d.fp.readOptionalInt(uniformProb, 6)) + } + } + if !d.segmentHeader.updateMap { + return + } + for i := range d.segmentHeader.prob { + if d.fp.readBit(uniformProb) { + d.segmentHeader.prob[i] = uint8(d.fp.readUint(uniformProb, 8)) + } else { + d.segmentHeader.prob[i] = 0xff + } + } +} + +// parseFilterHeader parses the filter header, as specified in section 9.4. +func (d *Decoder) parseFilterHeader() { + d.filterHeader.simple = d.fp.readBit(uniformProb) + d.filterHeader.level = int8(d.fp.readUint(uniformProb, 6)) + d.filterHeader.sharpness = uint8(d.fp.readUint(uniformProb, 3)) + d.filterHeader.useLFDelta = d.fp.readBit(uniformProb) + if d.filterHeader.useLFDelta && d.fp.readBit(uniformProb) { + for i := range d.filterHeader.refLFDelta { + d.filterHeader.refLFDelta[i] = int8(d.fp.readOptionalInt(uniformProb, 6)) + } + for i := range d.filterHeader.modeLFDelta { + d.filterHeader.modeLFDelta[i] = int8(d.fp.readOptionalInt(uniformProb, 6)) + } + } + if d.filterHeader.level == 0 { + return + } + if d.segmentHeader.useSegment { + for i := range d.filterHeader.perSegmentLevel { + strength := d.segmentHeader.filterStrength[i] + if d.segmentHeader.relativeDelta { + strength += d.filterHeader.level + } + d.filterHeader.perSegmentLevel[i] = strength + } + } else { + d.filterHeader.perSegmentLevel[0] = d.filterHeader.level + } + d.computeFilterParams() +} + +// parseOtherPartitions parses the other partitions, as specified in section 9.5. +func (d *Decoder) parseOtherPartitions() error { + const maxNOP = 1 << 3 + var partLens [maxNOP]int + d.nOP = 1 << d.fp.readUint(uniformProb, 2) + + // The final partition length is implied by the remaining chunk data + // (d.r.n) and the other d.nOP-1 partition lengths. Those d.nOP-1 partition + // lengths are stored as 24-bit uints, i.e. up to 16 MiB per partition. + n := 3 * (d.nOP - 1) + partLens[d.nOP-1] = d.r.n - n + if partLens[d.nOP-1] < 0 { + return io.ErrUnexpectedEOF + } + if n > 0 { + buf := make([]byte, n) + if err := d.r.ReadFull(buf); err != nil { + return err + } + for i := 0; i < d.nOP-1; i++ { + pl := int(buf[3*i+0]) | int(buf[3*i+1])<<8 | int(buf[3*i+2])<<16 + if pl > partLens[d.nOP-1] { + return io.ErrUnexpectedEOF + } + partLens[i] = pl + partLens[d.nOP-1] -= pl + } + } + + // We check if the final partition length can also fit into a 24-bit uint. + // Strictly speaking, this isn't part of the spec, but it guards against a + // malicious WEBP image that is too large to ReadFull the encoded DCT + // coefficients into memory, whether that's because the actual WEBP file is + // too large, or whether its RIFF metadata lists too large a chunk. + if 1<<24 <= partLens[d.nOP-1] { + return errors.New("vp8: too much data to decode") + } + + buf := make([]byte, d.r.n) + if err := d.r.ReadFull(buf); err != nil { + return err + } + for i, pl := range partLens { + if i == d.nOP { + break + } + d.op[i].init(buf[:pl]) + buf = buf[pl:] + } + return nil +} + +// parseOtherHeaders parses header information other than the frame header. +func (d *Decoder) parseOtherHeaders() error { + // Initialize and parse the first partition. + firstPartition := make([]byte, d.frameHeader.FirstPartitionLen) + if err := d.r.ReadFull(firstPartition); err != nil { + return err + } + d.fp.init(firstPartition) + if d.frameHeader.KeyFrame { + // Read and ignore the color space and pixel clamp values. They are + // specified in section 9.2, but are unimplemented. + d.fp.readBit(uniformProb) + d.fp.readBit(uniformProb) + } + d.parseSegmentHeader() + d.parseFilterHeader() + if err := d.parseOtherPartitions(); err != nil { + return err + } + d.parseQuant() + if !d.frameHeader.KeyFrame { + // Golden and AltRef frames are specified in section 9.7. + // TODO(nigeltao): implement. Note that they are only used for video, not still images. + return errors.New("vp8: Golden / AltRef frames are not implemented") + } + // Read and ignore the refreshLastFrameBuffer bit, specified in section 9.8. + // It applies only to video, and not still images. + d.fp.readBit(uniformProb) + d.parseTokenProb() + d.useSkipProb = d.fp.readBit(uniformProb) + if d.useSkipProb { + d.skipProb = uint8(d.fp.readUint(uniformProb, 8)) + } + if d.fp.unexpectedEOF { + return io.ErrUnexpectedEOF + } + return nil +} + +// DecodeFrame decodes the frame and returns it as an YCbCr image. +// The image's contents are valid up until the next call to Decoder.Init. +func (d *Decoder) DecodeFrame() (*image.YCbCr, error) { + d.ensureImg() + if err := d.parseOtherHeaders(); err != nil { + return nil, err + } + // Reconstruct the rows. + for mbx := 0; mbx < d.mbw; mbx++ { + d.upMB[mbx] = mb{} + } + for mby := 0; mby < d.mbh; mby++ { + d.leftMB = mb{} + for mbx := 0; mbx < d.mbw; mbx++ { + skip := d.reconstruct(mbx, mby) + fs := d.filterParams[d.segment][btou(!d.usePredY16)] + fs.inner = fs.inner || !skip + d.perMBFilterParams[d.mbw*mby+mbx] = fs + } + } + if d.fp.unexpectedEOF { + return nil, io.ErrUnexpectedEOF + } + for i := 0; i < d.nOP; i++ { + if d.op[i].unexpectedEOF { + return nil, io.ErrUnexpectedEOF + } + } + // Apply the loop filter. + // + // Even if we are using per-segment levels, section 15 says that "loop + // filtering must be skipped entirely if loop_filter_level at either the + // frame header level or macroblock override level is 0". + if d.filterHeader.level != 0 { + if d.filterHeader.simple { + d.simpleFilter() + } else { + d.normalFilter() + } + } + return d.img, nil +} diff --git a/vendor/golang.org/x/image/vp8/filter.go b/vendor/golang.org/x/image/vp8/filter.go new file mode 100644 index 0000000..e34a811 --- /dev/null +++ b/vendor/golang.org/x/image/vp8/filter.go @@ -0,0 +1,273 @@ +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package vp8 + +// filter2 modifies a 2-pixel wide or 2-pixel high band along an edge. +func filter2(pix []byte, level, index, iStep, jStep int) { + for n := 16; n > 0; n, index = n-1, index+iStep { + p1 := int(pix[index-2*jStep]) + p0 := int(pix[index-1*jStep]) + q0 := int(pix[index+0*jStep]) + q1 := int(pix[index+1*jStep]) + if abs(p0-q0)<<1+abs(p1-q1)>>1 > level { + continue + } + a := 3*(q0-p0) + clamp127(p1-q1) + a1 := clamp15((a + 4) >> 3) + a2 := clamp15((a + 3) >> 3) + pix[index-1*jStep] = clamp255(p0 + a2) + pix[index+0*jStep] = clamp255(q0 - a1) + } +} + +// filter246 modifies a 2-, 4- or 6-pixel wide or high band along an edge. +func filter246(pix []byte, n, level, ilevel, hlevel, index, iStep, jStep int, fourNotSix bool) { + for ; n > 0; n, index = n-1, index+iStep { + p3 := int(pix[index-4*jStep]) + p2 := int(pix[index-3*jStep]) + p1 := int(pix[index-2*jStep]) + p0 := int(pix[index-1*jStep]) + q0 := int(pix[index+0*jStep]) + q1 := int(pix[index+1*jStep]) + q2 := int(pix[index+2*jStep]) + q3 := int(pix[index+3*jStep]) + if abs(p0-q0)<<1+abs(p1-q1)>>1 > level { + continue + } + if abs(p3-p2) > ilevel || + abs(p2-p1) > ilevel || + abs(p1-p0) > ilevel || + abs(q1-q0) > ilevel || + abs(q2-q1) > ilevel || + abs(q3-q2) > ilevel { + continue + } + if abs(p1-p0) > hlevel || abs(q1-q0) > hlevel { + // Filter 2 pixels. + a := 3*(q0-p0) + clamp127(p1-q1) + a1 := clamp15((a + 4) >> 3) + a2 := clamp15((a + 3) >> 3) + pix[index-1*jStep] = clamp255(p0 + a2) + pix[index+0*jStep] = clamp255(q0 - a1) + } else if fourNotSix { + // Filter 4 pixels. + a := 3 * (q0 - p0) + a1 := clamp15((a + 4) >> 3) + a2 := clamp15((a + 3) >> 3) + a3 := (a1 + 1) >> 1 + pix[index-2*jStep] = clamp255(p1 + a3) + pix[index-1*jStep] = clamp255(p0 + a2) + pix[index+0*jStep] = clamp255(q0 - a1) + pix[index+1*jStep] = clamp255(q1 - a3) + } else { + // Filter 6 pixels. + a := clamp127(3*(q0-p0) + clamp127(p1-q1)) + a1 := (27*a + 63) >> 7 + a2 := (18*a + 63) >> 7 + a3 := (9*a + 63) >> 7 + pix[index-3*jStep] = clamp255(p2 + a3) + pix[index-2*jStep] = clamp255(p1 + a2) + pix[index-1*jStep] = clamp255(p0 + a1) + pix[index+0*jStep] = clamp255(q0 - a1) + pix[index+1*jStep] = clamp255(q1 - a2) + pix[index+2*jStep] = clamp255(q2 - a3) + } + } +} + +// simpleFilter implements the simple filter, as specified in section 15.2. +func (d *Decoder) simpleFilter() { + for mby := 0; mby < d.mbh; mby++ { + for mbx := 0; mbx < d.mbw; mbx++ { + f := d.perMBFilterParams[d.mbw*mby+mbx] + if f.level == 0 { + continue + } + l := int(f.level) + yIndex := (mby*d.img.YStride + mbx) * 16 + if mbx > 0 { + filter2(d.img.Y, l+4, yIndex, d.img.YStride, 1) + } + if f.inner { + filter2(d.img.Y, l, yIndex+0x4, d.img.YStride, 1) + filter2(d.img.Y, l, yIndex+0x8, d.img.YStride, 1) + filter2(d.img.Y, l, yIndex+0xc, d.img.YStride, 1) + } + if mby > 0 { + filter2(d.img.Y, l+4, yIndex, 1, d.img.YStride) + } + if f.inner { + filter2(d.img.Y, l, yIndex+d.img.YStride*0x4, 1, d.img.YStride) + filter2(d.img.Y, l, yIndex+d.img.YStride*0x8, 1, d.img.YStride) + filter2(d.img.Y, l, yIndex+d.img.YStride*0xc, 1, d.img.YStride) + } + } + } +} + +// normalFilter implements the normal filter, as specified in section 15.3. +func (d *Decoder) normalFilter() { + for mby := 0; mby < d.mbh; mby++ { + for mbx := 0; mbx < d.mbw; mbx++ { + f := d.perMBFilterParams[d.mbw*mby+mbx] + if f.level == 0 { + continue + } + l, il, hl := int(f.level), int(f.ilevel), int(f.hlevel) + yIndex := (mby*d.img.YStride + mbx) * 16 + cIndex := (mby*d.img.CStride + mbx) * 8 + if mbx > 0 { + filter246(d.img.Y, 16, l+4, il, hl, yIndex, d.img.YStride, 1, false) + filter246(d.img.Cb, 8, l+4, il, hl, cIndex, d.img.CStride, 1, false) + filter246(d.img.Cr, 8, l+4, il, hl, cIndex, d.img.CStride, 1, false) + } + if f.inner { + filter246(d.img.Y, 16, l, il, hl, yIndex+0x4, d.img.YStride, 1, true) + filter246(d.img.Y, 16, l, il, hl, yIndex+0x8, d.img.YStride, 1, true) + filter246(d.img.Y, 16, l, il, hl, yIndex+0xc, d.img.YStride, 1, true) + filter246(d.img.Cb, 8, l, il, hl, cIndex+0x4, d.img.CStride, 1, true) + filter246(d.img.Cr, 8, l, il, hl, cIndex+0x4, d.img.CStride, 1, true) + } + if mby > 0 { + filter246(d.img.Y, 16, l+4, il, hl, yIndex, 1, d.img.YStride, false) + filter246(d.img.Cb, 8, l+4, il, hl, cIndex, 1, d.img.CStride, false) + filter246(d.img.Cr, 8, l+4, il, hl, cIndex, 1, d.img.CStride, false) + } + if f.inner { + filter246(d.img.Y, 16, l, il, hl, yIndex+d.img.YStride*0x4, 1, d.img.YStride, true) + filter246(d.img.Y, 16, l, il, hl, yIndex+d.img.YStride*0x8, 1, d.img.YStride, true) + filter246(d.img.Y, 16, l, il, hl, yIndex+d.img.YStride*0xc, 1, d.img.YStride, true) + filter246(d.img.Cb, 8, l, il, hl, cIndex+d.img.CStride*0x4, 1, d.img.CStride, true) + filter246(d.img.Cr, 8, l, il, hl, cIndex+d.img.CStride*0x4, 1, d.img.CStride, true) + } + } + } +} + +// filterParam holds the loop filter parameters for a macroblock. +type filterParam struct { + // The first three fields are thresholds used by the loop filter to smooth + // over the edges and interior of a macroblock. level is used by both the + // simple and normal filters. The inner level and high edge variance level + // are only used by the normal filter. + level, ilevel, hlevel uint8 + // inner is whether the inner loop filter cannot be optimized out as a + // no-op for this particular macroblock. + inner bool +} + +// computeFilterParams computes the loop filter parameters, as specified in +// section 15.4. +func (d *Decoder) computeFilterParams() { + for i := range d.filterParams { + baseLevel := d.filterHeader.level + if d.segmentHeader.useSegment { + baseLevel = d.segmentHeader.filterStrength[i] + if d.segmentHeader.relativeDelta { + baseLevel += d.filterHeader.level + } + } + + for j := range d.filterParams[i] { + p := &d.filterParams[i][j] + p.inner = j != 0 + level := baseLevel + if d.filterHeader.useLFDelta { + // The libwebp C code has a "TODO: only CURRENT is handled for now." + level += d.filterHeader.refLFDelta[0] + if j != 0 { + level += d.filterHeader.modeLFDelta[0] + } + } + if level <= 0 { + p.level = 0 + continue + } + if level > 63 { + level = 63 + } + ilevel := level + if d.filterHeader.sharpness > 0 { + if d.filterHeader.sharpness > 4 { + ilevel >>= 2 + } else { + ilevel >>= 1 + } + if x := int8(9 - d.filterHeader.sharpness); ilevel > x { + ilevel = x + } + } + if ilevel < 1 { + ilevel = 1 + } + p.ilevel = uint8(ilevel) + p.level = uint8(2*level + ilevel) + if d.frameHeader.KeyFrame { + if level < 15 { + p.hlevel = 0 + } else if level < 40 { + p.hlevel = 1 + } else { + p.hlevel = 2 + } + } else { + if level < 15 { + p.hlevel = 0 + } else if level < 20 { + p.hlevel = 1 + } else if level < 40 { + p.hlevel = 2 + } else { + p.hlevel = 3 + } + } + } + } +} + +// intSize is either 32 or 64. +const intSize = 32 << (^uint(0) >> 63) + +func abs(x int) int { + // m := -1 if x < 0. m := 0 otherwise. + m := x >> (intSize - 1) + + // In two's complement representation, the negative number + // of any number (except the smallest one) can be computed + // by flipping all the bits and add 1. This is faster than + // code with a branch. + // See Hacker's Delight, section 2-4. + return (x ^ m) - m +} + +func clamp15(x int) int { + if x < -16 { + return -16 + } + if x > 15 { + return 15 + } + return x +} + +func clamp127(x int) int { + if x < -128 { + return -128 + } + if x > 127 { + return 127 + } + return x +} + +func clamp255(x int) uint8 { + if x < 0 { + return 0 + } + if x > 255 { + return 255 + } + return uint8(x) +} diff --git a/vendor/golang.org/x/image/vp8/idct.go b/vendor/golang.org/x/image/vp8/idct.go new file mode 100644 index 0000000..929af2c --- /dev/null +++ b/vendor/golang.org/x/image/vp8/idct.go @@ -0,0 +1,98 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package vp8 + +// This file implements the inverse Discrete Cosine Transform and the inverse +// Walsh Hadamard Transform (WHT), as specified in sections 14.3 and 14.4. + +func clip8(i int32) uint8 { + if i < 0 { + return 0 + } + if i > 255 { + return 255 + } + return uint8(i) +} + +func (z *Decoder) inverseDCT4(y, x, coeffBase int) { + const ( + c1 = 85627 // 65536 * cos(pi/8) * sqrt(2). + c2 = 35468 // 65536 * sin(pi/8) * sqrt(2). + ) + var m [4][4]int32 + for i := 0; i < 4; i++ { + a := int32(z.coeff[coeffBase+0]) + int32(z.coeff[coeffBase+8]) + b := int32(z.coeff[coeffBase+0]) - int32(z.coeff[coeffBase+8]) + c := (int32(z.coeff[coeffBase+4])*c2)>>16 - (int32(z.coeff[coeffBase+12])*c1)>>16 + d := (int32(z.coeff[coeffBase+4])*c1)>>16 + (int32(z.coeff[coeffBase+12])*c2)>>16 + m[i][0] = a + d + m[i][1] = b + c + m[i][2] = b - c + m[i][3] = a - d + coeffBase++ + } + for j := 0; j < 4; j++ { + dc := m[0][j] + 4 + a := dc + m[2][j] + b := dc - m[2][j] + c := (m[1][j]*c2)>>16 - (m[3][j]*c1)>>16 + d := (m[1][j]*c1)>>16 + (m[3][j]*c2)>>16 + z.ybr[y+j][x+0] = clip8(int32(z.ybr[y+j][x+0]) + (a+d)>>3) + z.ybr[y+j][x+1] = clip8(int32(z.ybr[y+j][x+1]) + (b+c)>>3) + z.ybr[y+j][x+2] = clip8(int32(z.ybr[y+j][x+2]) + (b-c)>>3) + z.ybr[y+j][x+3] = clip8(int32(z.ybr[y+j][x+3]) + (a-d)>>3) + } +} + +func (z *Decoder) inverseDCT4DCOnly(y, x, coeffBase int) { + dc := (int32(z.coeff[coeffBase+0]) + 4) >> 3 + for j := 0; j < 4; j++ { + for i := 0; i < 4; i++ { + z.ybr[y+j][x+i] = clip8(int32(z.ybr[y+j][x+i]) + dc) + } + } +} + +func (z *Decoder) inverseDCT8(y, x, coeffBase int) { + z.inverseDCT4(y+0, x+0, coeffBase+0*16) + z.inverseDCT4(y+0, x+4, coeffBase+1*16) + z.inverseDCT4(y+4, x+0, coeffBase+2*16) + z.inverseDCT4(y+4, x+4, coeffBase+3*16) +} + +func (z *Decoder) inverseDCT8DCOnly(y, x, coeffBase int) { + z.inverseDCT4DCOnly(y+0, x+0, coeffBase+0*16) + z.inverseDCT4DCOnly(y+0, x+4, coeffBase+1*16) + z.inverseDCT4DCOnly(y+4, x+0, coeffBase+2*16) + z.inverseDCT4DCOnly(y+4, x+4, coeffBase+3*16) +} + +func (d *Decoder) inverseWHT16() { + var m [16]int32 + for i := 0; i < 4; i++ { + a0 := int32(d.coeff[384+0+i]) + int32(d.coeff[384+12+i]) + a1 := int32(d.coeff[384+4+i]) + int32(d.coeff[384+8+i]) + a2 := int32(d.coeff[384+4+i]) - int32(d.coeff[384+8+i]) + a3 := int32(d.coeff[384+0+i]) - int32(d.coeff[384+12+i]) + m[0+i] = a0 + a1 + m[8+i] = a0 - a1 + m[4+i] = a3 + a2 + m[12+i] = a3 - a2 + } + out := 0 + for i := 0; i < 4; i++ { + dc := m[0+i*4] + 3 + a0 := dc + m[3+i*4] + a1 := m[1+i*4] + m[2+i*4] + a2 := m[1+i*4] - m[2+i*4] + a3 := dc - m[3+i*4] + d.coeff[out+0] = int16((a0 + a1) >> 3) + d.coeff[out+16] = int16((a3 + a2) >> 3) + d.coeff[out+32] = int16((a0 - a1) >> 3) + d.coeff[out+48] = int16((a3 - a2) >> 3) + out += 64 + } +} diff --git a/vendor/golang.org/x/image/vp8/partition.go b/vendor/golang.org/x/image/vp8/partition.go new file mode 100644 index 0000000..72288bd --- /dev/null +++ b/vendor/golang.org/x/image/vp8/partition.go @@ -0,0 +1,129 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package vp8 + +// Each VP8 frame consists of between 2 and 9 bitstream partitions. +// Each partition is byte-aligned and is independently arithmetic-encoded. +// +// This file implements decoding a partition's bitstream, as specified in +// chapter 7. The implementation follows libwebp's approach instead of the +// specification's reference C implementation. For example, we use a look-up +// table instead of a for loop to recalibrate the encoded range. + +var ( + lutShift = [127]uint8{ + 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4, + 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, + 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, + 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, + } + lutRangeM1 = [127]uint8{ + 127, + 127, 191, + 127, 159, 191, 223, + 127, 143, 159, 175, 191, 207, 223, 239, + 127, 135, 143, 151, 159, 167, 175, 183, 191, 199, 207, 215, 223, 231, 239, 247, + 127, 131, 135, 139, 143, 147, 151, 155, 159, 163, 167, 171, 175, 179, 183, 187, + 191, 195, 199, 203, 207, 211, 215, 219, 223, 227, 231, 235, 239, 243, 247, 251, + 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, + 159, 161, 163, 165, 167, 169, 171, 173, 175, 177, 179, 181, 183, 185, 187, 189, + 191, 193, 195, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, + 223, 225, 227, 229, 231, 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, + } +) + +// uniformProb represents a 50% probability that the next bit is 0. +const uniformProb = 128 + +// partition holds arithmetic-coded bits. +type partition struct { + // buf is the input bytes. + buf []byte + // r is how many of buf's bytes have been consumed. + r int + // rangeM1 is range minus 1, where range is in the arithmetic coding sense, + // not the Go language sense. + rangeM1 uint32 + // bits and nBits hold those bits shifted out of buf but not yet consumed. + bits uint32 + nBits uint8 + // unexpectedEOF tells whether we tried to read past buf. + unexpectedEOF bool +} + +// init initializes the partition. +func (p *partition) init(buf []byte) { + p.buf = buf + p.r = 0 + p.rangeM1 = 254 + p.bits = 0 + p.nBits = 0 + p.unexpectedEOF = false +} + +// readBit returns the next bit. +func (p *partition) readBit(prob uint8) bool { + if p.nBits < 8 { + if p.r >= len(p.buf) { + p.unexpectedEOF = true + return false + } + // Expression split for 386 compiler. + x := uint32(p.buf[p.r]) + p.bits |= x << (8 - p.nBits) + p.r++ + p.nBits += 8 + } + split := (p.rangeM1*uint32(prob))>>8 + 1 + bit := p.bits >= split<<8 + if bit { + p.rangeM1 -= split + p.bits -= split << 8 + } else { + p.rangeM1 = split - 1 + } + if p.rangeM1 < 127 { + shift := lutShift[p.rangeM1] + p.rangeM1 = uint32(lutRangeM1[p.rangeM1]) + p.bits <<= shift + p.nBits -= shift + } + return bit +} + +// readUint returns the next n-bit unsigned integer. +func (p *partition) readUint(prob, n uint8) uint32 { + var u uint32 + for n > 0 { + n-- + if p.readBit(prob) { + u |= 1 << n + } + } + return u +} + +// readInt returns the next n-bit signed integer. +func (p *partition) readInt(prob, n uint8) int32 { + u := p.readUint(prob, n) + b := p.readBit(prob) + if b { + return -int32(u) + } + return int32(u) +} + +// readOptionalInt returns the next n-bit signed integer in an encoding +// where the likely result is zero. +func (p *partition) readOptionalInt(prob, n uint8) int32 { + if !p.readBit(prob) { + return 0 + } + return p.readInt(prob, n) +} diff --git a/vendor/golang.org/x/image/vp8/pred.go b/vendor/golang.org/x/image/vp8/pred.go new file mode 100644 index 0000000..58c2689 --- /dev/null +++ b/vendor/golang.org/x/image/vp8/pred.go @@ -0,0 +1,201 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package vp8 + +// This file implements parsing the predictor modes, as specified in chapter +// 11. + +func (d *Decoder) parsePredModeY16(mbx int) { + var p uint8 + if !d.fp.readBit(156) { + if !d.fp.readBit(163) { + p = predDC + } else { + p = predVE + } + } else if !d.fp.readBit(128) { + p = predHE + } else { + p = predTM + } + for i := 0; i < 4; i++ { + d.upMB[mbx].pred[i] = p + d.leftMB.pred[i] = p + } + d.predY16 = p +} + +func (d *Decoder) parsePredModeC8() { + if !d.fp.readBit(142) { + d.predC8 = predDC + } else if !d.fp.readBit(114) { + d.predC8 = predVE + } else if !d.fp.readBit(183) { + d.predC8 = predHE + } else { + d.predC8 = predTM + } +} + +func (d *Decoder) parsePredModeY4(mbx int) { + for j := 0; j < 4; j++ { + p := d.leftMB.pred[j] + for i := 0; i < 4; i++ { + prob := &predProb[d.upMB[mbx].pred[i]][p] + if !d.fp.readBit(prob[0]) { + p = predDC + } else if !d.fp.readBit(prob[1]) { + p = predTM + } else if !d.fp.readBit(prob[2]) { + p = predVE + } else if !d.fp.readBit(prob[3]) { + if !d.fp.readBit(prob[4]) { + p = predHE + } else if !d.fp.readBit(prob[5]) { + p = predRD + } else { + p = predVR + } + } else if !d.fp.readBit(prob[6]) { + p = predLD + } else if !d.fp.readBit(prob[7]) { + p = predVL + } else if !d.fp.readBit(prob[8]) { + p = predHD + } else { + p = predHU + } + d.predY4[j][i] = p + d.upMB[mbx].pred[i] = p + } + d.leftMB.pred[j] = p + } +} + +// predProb are the probabilities to decode a 4x4 region's predictor mode given +// the predictor modes of the regions above and left of it. +// These values are specified in section 11.5. +var predProb = [nPred][nPred][9]uint8{ + { + {231, 120, 48, 89, 115, 113, 120, 152, 112}, + {152, 179, 64, 126, 170, 118, 46, 70, 95}, + {175, 69, 143, 80, 85, 82, 72, 155, 103}, + {56, 58, 10, 171, 218, 189, 17, 13, 152}, + {114, 26, 17, 163, 44, 195, 21, 10, 173}, + {121, 24, 80, 195, 26, 62, 44, 64, 85}, + {144, 71, 10, 38, 171, 213, 144, 34, 26}, + {170, 46, 55, 19, 136, 160, 33, 206, 71}, + {63, 20, 8, 114, 114, 208, 12, 9, 226}, + {81, 40, 11, 96, 182, 84, 29, 16, 36}, + }, + { + {134, 183, 89, 137, 98, 101, 106, 165, 148}, + {72, 187, 100, 130, 157, 111, 32, 75, 80}, + {66, 102, 167, 99, 74, 62, 40, 234, 128}, + {41, 53, 9, 178, 241, 141, 26, 8, 107}, + {74, 43, 26, 146, 73, 166, 49, 23, 157}, + {65, 38, 105, 160, 51, 52, 31, 115, 128}, + {104, 79, 12, 27, 217, 255, 87, 17, 7}, + {87, 68, 71, 44, 114, 51, 15, 186, 23}, + {47, 41, 14, 110, 182, 183, 21, 17, 194}, + {66, 45, 25, 102, 197, 189, 23, 18, 22}, + }, + { + {88, 88, 147, 150, 42, 46, 45, 196, 205}, + {43, 97, 183, 117, 85, 38, 35, 179, 61}, + {39, 53, 200, 87, 26, 21, 43, 232, 171}, + {56, 34, 51, 104, 114, 102, 29, 93, 77}, + {39, 28, 85, 171, 58, 165, 90, 98, 64}, + {34, 22, 116, 206, 23, 34, 43, 166, 73}, + {107, 54, 32, 26, 51, 1, 81, 43, 31}, + {68, 25, 106, 22, 64, 171, 36, 225, 114}, + {34, 19, 21, 102, 132, 188, 16, 76, 124}, + {62, 18, 78, 95, 85, 57, 50, 48, 51}, + }, + { + {193, 101, 35, 159, 215, 111, 89, 46, 111}, + {60, 148, 31, 172, 219, 228, 21, 18, 111}, + {112, 113, 77, 85, 179, 255, 38, 120, 114}, + {40, 42, 1, 196, 245, 209, 10, 25, 109}, + {88, 43, 29, 140, 166, 213, 37, 43, 154}, + {61, 63, 30, 155, 67, 45, 68, 1, 209}, + {100, 80, 8, 43, 154, 1, 51, 26, 71}, + {142, 78, 78, 16, 255, 128, 34, 197, 171}, + {41, 40, 5, 102, 211, 183, 4, 1, 221}, + {51, 50, 17, 168, 209, 192, 23, 25, 82}, + }, + { + {138, 31, 36, 171, 27, 166, 38, 44, 229}, + {67, 87, 58, 169, 82, 115, 26, 59, 179}, + {63, 59, 90, 180, 59, 166, 93, 73, 154}, + {40, 40, 21, 116, 143, 209, 34, 39, 175}, + {47, 15, 16, 183, 34, 223, 49, 45, 183}, + {46, 17, 33, 183, 6, 98, 15, 32, 183}, + {57, 46, 22, 24, 128, 1, 54, 17, 37}, + {65, 32, 73, 115, 28, 128, 23, 128, 205}, + {40, 3, 9, 115, 51, 192, 18, 6, 223}, + {87, 37, 9, 115, 59, 77, 64, 21, 47}, + }, + { + {104, 55, 44, 218, 9, 54, 53, 130, 226}, + {64, 90, 70, 205, 40, 41, 23, 26, 57}, + {54, 57, 112, 184, 5, 41, 38, 166, 213}, + {30, 34, 26, 133, 152, 116, 10, 32, 134}, + {39, 19, 53, 221, 26, 114, 32, 73, 255}, + {31, 9, 65, 234, 2, 15, 1, 118, 73}, + {75, 32, 12, 51, 192, 255, 160, 43, 51}, + {88, 31, 35, 67, 102, 85, 55, 186, 85}, + {56, 21, 23, 111, 59, 205, 45, 37, 192}, + {55, 38, 70, 124, 73, 102, 1, 34, 98}, + }, + { + {125, 98, 42, 88, 104, 85, 117, 175, 82}, + {95, 84, 53, 89, 128, 100, 113, 101, 45}, + {75, 79, 123, 47, 51, 128, 81, 171, 1}, + {57, 17, 5, 71, 102, 57, 53, 41, 49}, + {38, 33, 13, 121, 57, 73, 26, 1, 85}, + {41, 10, 67, 138, 77, 110, 90, 47, 114}, + {115, 21, 2, 10, 102, 255, 166, 23, 6}, + {101, 29, 16, 10, 85, 128, 101, 196, 26}, + {57, 18, 10, 102, 102, 213, 34, 20, 43}, + {117, 20, 15, 36, 163, 128, 68, 1, 26}, + }, + { + {102, 61, 71, 37, 34, 53, 31, 243, 192}, + {69, 60, 71, 38, 73, 119, 28, 222, 37}, + {68, 45, 128, 34, 1, 47, 11, 245, 171}, + {62, 17, 19, 70, 146, 85, 55, 62, 70}, + {37, 43, 37, 154, 100, 163, 85, 160, 1}, + {63, 9, 92, 136, 28, 64, 32, 201, 85}, + {75, 15, 9, 9, 64, 255, 184, 119, 16}, + {86, 6, 28, 5, 64, 255, 25, 248, 1}, + {56, 8, 17, 132, 137, 255, 55, 116, 128}, + {58, 15, 20, 82, 135, 57, 26, 121, 40}, + }, + { + {164, 50, 31, 137, 154, 133, 25, 35, 218}, + {51, 103, 44, 131, 131, 123, 31, 6, 158}, + {86, 40, 64, 135, 148, 224, 45, 183, 128}, + {22, 26, 17, 131, 240, 154, 14, 1, 209}, + {45, 16, 21, 91, 64, 222, 7, 1, 197}, + {56, 21, 39, 155, 60, 138, 23, 102, 213}, + {83, 12, 13, 54, 192, 255, 68, 47, 28}, + {85, 26, 85, 85, 128, 128, 32, 146, 171}, + {18, 11, 7, 63, 144, 171, 4, 4, 246}, + {35, 27, 10, 146, 174, 171, 12, 26, 128}, + }, + { + {190, 80, 35, 99, 180, 80, 126, 54, 45}, + {85, 126, 47, 87, 176, 51, 41, 20, 32}, + {101, 75, 128, 139, 118, 146, 116, 128, 85}, + {56, 41, 15, 176, 236, 85, 37, 9, 62}, + {71, 30, 17, 119, 118, 255, 17, 18, 138}, + {101, 38, 60, 138, 55, 70, 43, 26, 142}, + {146, 36, 19, 30, 171, 255, 97, 27, 20}, + {138, 45, 61, 62, 219, 1, 81, 188, 64}, + {32, 41, 20, 117, 151, 142, 20, 21, 163}, + {112, 19, 12, 61, 195, 128, 48, 4, 24}, + }, +} diff --git a/vendor/golang.org/x/image/vp8/predfunc.go b/vendor/golang.org/x/image/vp8/predfunc.go new file mode 100644 index 0000000..f899958 --- /dev/null +++ b/vendor/golang.org/x/image/vp8/predfunc.go @@ -0,0 +1,553 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package vp8 + +// This file implements the predicition functions, as specified in chapter 12. +// +// For each macroblock (of 1x16x16 luma and 2x8x8 chroma coefficients), the +// luma values are either predicted as one large 16x16 region or 16 separate +// 4x4 regions. The chroma values are always predicted as one 8x8 region. +// +// For 4x4 regions, the target block's predicted values (Xs) are a function of +// its previously-decoded top and left border values, as well as a number of +// pixels from the top-right: +// +// a b c d e f g h +// p X X X X +// q X X X X +// r X X X X +// s X X X X +// +// The predictor modes are: +// - DC: all Xs = (b + c + d + e + p + q + r + s + 4) / 8. +// - TM: the first X = (b + p - a), the second X = (c + p - a), and so on. +// - VE: each X = the weighted average of its column's top value and that +// value's neighbors, i.e. averages of abc, bcd, cde or def. +// - HE: similar to VE except rows instead of columns, and the final row is +// an average of r, s and s. +// - RD, VR, LD, VL, HD, HU: these diagonal modes ("Right Down", "Vertical +// Right", etc) are more complicated and are described in section 12.3. +// All Xs are clipped to the range [0, 255]. +// +// For 8x8 and 16x16 regions, the target block's predicted values are a +// function of the top and left border values without the top-right overhang, +// i.e. without the 8x8 or 16x16 equivalent of f, g and h. Furthermore: +// - There are no diagonal predictor modes, only DC, TM, VE and HE. +// - The DC mode has variants for macroblocks in the top row and/or left +// column, i.e. for macroblocks with mby == 0 || mbx == 0. +// - The VE and HE modes take only the column top or row left values; they do +// not smooth that top/left value with its neighbors. + +// nPred is the number of predictor modes, not including the Top/Left versions +// of the DC predictor mode. +const nPred = 10 + +const ( + predDC = iota + predTM + predVE + predHE + predRD + predVR + predLD + predVL + predHD + predHU + predDCTop + predDCLeft + predDCTopLeft +) + +func checkTopLeftPred(mbx, mby int, p uint8) uint8 { + if p != predDC { + return p + } + if mbx == 0 { + if mby == 0 { + return predDCTopLeft + } + return predDCLeft + } + if mby == 0 { + return predDCTop + } + return predDC +} + +var predFunc4 = [...]func(*Decoder, int, int){ + predFunc4DC, + predFunc4TM, + predFunc4VE, + predFunc4HE, + predFunc4RD, + predFunc4VR, + predFunc4LD, + predFunc4VL, + predFunc4HD, + predFunc4HU, + nil, + nil, + nil, +} + +var predFunc8 = [...]func(*Decoder, int, int){ + predFunc8DC, + predFunc8TM, + predFunc8VE, + predFunc8HE, + nil, + nil, + nil, + nil, + nil, + nil, + predFunc8DCTop, + predFunc8DCLeft, + predFunc8DCTopLeft, +} + +var predFunc16 = [...]func(*Decoder, int, int){ + predFunc16DC, + predFunc16TM, + predFunc16VE, + predFunc16HE, + nil, + nil, + nil, + nil, + nil, + nil, + predFunc16DCTop, + predFunc16DCLeft, + predFunc16DCTopLeft, +} + +func predFunc4DC(z *Decoder, y, x int) { + sum := uint32(4) + for i := 0; i < 4; i++ { + sum += uint32(z.ybr[y-1][x+i]) + } + for j := 0; j < 4; j++ { + sum += uint32(z.ybr[y+j][x-1]) + } + avg := uint8(sum / 8) + for j := 0; j < 4; j++ { + for i := 0; i < 4; i++ { + z.ybr[y+j][x+i] = avg + } + } +} + +func predFunc4TM(z *Decoder, y, x int) { + delta0 := -int32(z.ybr[y-1][x-1]) + for j := 0; j < 4; j++ { + delta1 := delta0 + int32(z.ybr[y+j][x-1]) + for i := 0; i < 4; i++ { + delta2 := delta1 + int32(z.ybr[y-1][x+i]) + z.ybr[y+j][x+i] = uint8(clip(delta2, 0, 255)) + } + } +} + +func predFunc4VE(z *Decoder, y, x int) { + a := int32(z.ybr[y-1][x-1]) + b := int32(z.ybr[y-1][x+0]) + c := int32(z.ybr[y-1][x+1]) + d := int32(z.ybr[y-1][x+2]) + e := int32(z.ybr[y-1][x+3]) + f := int32(z.ybr[y-1][x+4]) + abc := uint8((a + 2*b + c + 2) / 4) + bcd := uint8((b + 2*c + d + 2) / 4) + cde := uint8((c + 2*d + e + 2) / 4) + def := uint8((d + 2*e + f + 2) / 4) + for j := 0; j < 4; j++ { + z.ybr[y+j][x+0] = abc + z.ybr[y+j][x+1] = bcd + z.ybr[y+j][x+2] = cde + z.ybr[y+j][x+3] = def + } +} + +func predFunc4HE(z *Decoder, y, x int) { + s := int32(z.ybr[y+3][x-1]) + r := int32(z.ybr[y+2][x-1]) + q := int32(z.ybr[y+1][x-1]) + p := int32(z.ybr[y+0][x-1]) + a := int32(z.ybr[y-1][x-1]) + ssr := uint8((s + 2*s + r + 2) / 4) + srq := uint8((s + 2*r + q + 2) / 4) + rqp := uint8((r + 2*q + p + 2) / 4) + apq := uint8((a + 2*p + q + 2) / 4) + for i := 0; i < 4; i++ { + z.ybr[y+0][x+i] = apq + z.ybr[y+1][x+i] = rqp + z.ybr[y+2][x+i] = srq + z.ybr[y+3][x+i] = ssr + } +} + +func predFunc4RD(z *Decoder, y, x int) { + s := int32(z.ybr[y+3][x-1]) + r := int32(z.ybr[y+2][x-1]) + q := int32(z.ybr[y+1][x-1]) + p := int32(z.ybr[y+0][x-1]) + a := int32(z.ybr[y-1][x-1]) + b := int32(z.ybr[y-1][x+0]) + c := int32(z.ybr[y-1][x+1]) + d := int32(z.ybr[y-1][x+2]) + e := int32(z.ybr[y-1][x+3]) + srq := uint8((s + 2*r + q + 2) / 4) + rqp := uint8((r + 2*q + p + 2) / 4) + qpa := uint8((q + 2*p + a + 2) / 4) + pab := uint8((p + 2*a + b + 2) / 4) + abc := uint8((a + 2*b + c + 2) / 4) + bcd := uint8((b + 2*c + d + 2) / 4) + cde := uint8((c + 2*d + e + 2) / 4) + z.ybr[y+0][x+0] = pab + z.ybr[y+0][x+1] = abc + z.ybr[y+0][x+2] = bcd + z.ybr[y+0][x+3] = cde + z.ybr[y+1][x+0] = qpa + z.ybr[y+1][x+1] = pab + z.ybr[y+1][x+2] = abc + z.ybr[y+1][x+3] = bcd + z.ybr[y+2][x+0] = rqp + z.ybr[y+2][x+1] = qpa + z.ybr[y+2][x+2] = pab + z.ybr[y+2][x+3] = abc + z.ybr[y+3][x+0] = srq + z.ybr[y+3][x+1] = rqp + z.ybr[y+3][x+2] = qpa + z.ybr[y+3][x+3] = pab +} + +func predFunc4VR(z *Decoder, y, x int) { + r := int32(z.ybr[y+2][x-1]) + q := int32(z.ybr[y+1][x-1]) + p := int32(z.ybr[y+0][x-1]) + a := int32(z.ybr[y-1][x-1]) + b := int32(z.ybr[y-1][x+0]) + c := int32(z.ybr[y-1][x+1]) + d := int32(z.ybr[y-1][x+2]) + e := int32(z.ybr[y-1][x+3]) + ab := uint8((a + b + 1) / 2) + bc := uint8((b + c + 1) / 2) + cd := uint8((c + d + 1) / 2) + de := uint8((d + e + 1) / 2) + rqp := uint8((r + 2*q + p + 2) / 4) + qpa := uint8((q + 2*p + a + 2) / 4) + pab := uint8((p + 2*a + b + 2) / 4) + abc := uint8((a + 2*b + c + 2) / 4) + bcd := uint8((b + 2*c + d + 2) / 4) + cde := uint8((c + 2*d + e + 2) / 4) + z.ybr[y+0][x+0] = ab + z.ybr[y+0][x+1] = bc + z.ybr[y+0][x+2] = cd + z.ybr[y+0][x+3] = de + z.ybr[y+1][x+0] = pab + z.ybr[y+1][x+1] = abc + z.ybr[y+1][x+2] = bcd + z.ybr[y+1][x+3] = cde + z.ybr[y+2][x+0] = qpa + z.ybr[y+2][x+1] = ab + z.ybr[y+2][x+2] = bc + z.ybr[y+2][x+3] = cd + z.ybr[y+3][x+0] = rqp + z.ybr[y+3][x+1] = pab + z.ybr[y+3][x+2] = abc + z.ybr[y+3][x+3] = bcd +} + +func predFunc4LD(z *Decoder, y, x int) { + a := int32(z.ybr[y-1][x+0]) + b := int32(z.ybr[y-1][x+1]) + c := int32(z.ybr[y-1][x+2]) + d := int32(z.ybr[y-1][x+3]) + e := int32(z.ybr[y-1][x+4]) + f := int32(z.ybr[y-1][x+5]) + g := int32(z.ybr[y-1][x+6]) + h := int32(z.ybr[y-1][x+7]) + abc := uint8((a + 2*b + c + 2) / 4) + bcd := uint8((b + 2*c + d + 2) / 4) + cde := uint8((c + 2*d + e + 2) / 4) + def := uint8((d + 2*e + f + 2) / 4) + efg := uint8((e + 2*f + g + 2) / 4) + fgh := uint8((f + 2*g + h + 2) / 4) + ghh := uint8((g + 2*h + h + 2) / 4) + z.ybr[y+0][x+0] = abc + z.ybr[y+0][x+1] = bcd + z.ybr[y+0][x+2] = cde + z.ybr[y+0][x+3] = def + z.ybr[y+1][x+0] = bcd + z.ybr[y+1][x+1] = cde + z.ybr[y+1][x+2] = def + z.ybr[y+1][x+3] = efg + z.ybr[y+2][x+0] = cde + z.ybr[y+2][x+1] = def + z.ybr[y+2][x+2] = efg + z.ybr[y+2][x+3] = fgh + z.ybr[y+3][x+0] = def + z.ybr[y+3][x+1] = efg + z.ybr[y+3][x+2] = fgh + z.ybr[y+3][x+3] = ghh +} + +func predFunc4VL(z *Decoder, y, x int) { + a := int32(z.ybr[y-1][x+0]) + b := int32(z.ybr[y-1][x+1]) + c := int32(z.ybr[y-1][x+2]) + d := int32(z.ybr[y-1][x+3]) + e := int32(z.ybr[y-1][x+4]) + f := int32(z.ybr[y-1][x+5]) + g := int32(z.ybr[y-1][x+6]) + h := int32(z.ybr[y-1][x+7]) + ab := uint8((a + b + 1) / 2) + bc := uint8((b + c + 1) / 2) + cd := uint8((c + d + 1) / 2) + de := uint8((d + e + 1) / 2) + abc := uint8((a + 2*b + c + 2) / 4) + bcd := uint8((b + 2*c + d + 2) / 4) + cde := uint8((c + 2*d + e + 2) / 4) + def := uint8((d + 2*e + f + 2) / 4) + efg := uint8((e + 2*f + g + 2) / 4) + fgh := uint8((f + 2*g + h + 2) / 4) + z.ybr[y+0][x+0] = ab + z.ybr[y+0][x+1] = bc + z.ybr[y+0][x+2] = cd + z.ybr[y+0][x+3] = de + z.ybr[y+1][x+0] = abc + z.ybr[y+1][x+1] = bcd + z.ybr[y+1][x+2] = cde + z.ybr[y+1][x+3] = def + z.ybr[y+2][x+0] = bc + z.ybr[y+2][x+1] = cd + z.ybr[y+2][x+2] = de + z.ybr[y+2][x+3] = efg + z.ybr[y+3][x+0] = bcd + z.ybr[y+3][x+1] = cde + z.ybr[y+3][x+2] = def + z.ybr[y+3][x+3] = fgh +} + +func predFunc4HD(z *Decoder, y, x int) { + s := int32(z.ybr[y+3][x-1]) + r := int32(z.ybr[y+2][x-1]) + q := int32(z.ybr[y+1][x-1]) + p := int32(z.ybr[y+0][x-1]) + a := int32(z.ybr[y-1][x-1]) + b := int32(z.ybr[y-1][x+0]) + c := int32(z.ybr[y-1][x+1]) + d := int32(z.ybr[y-1][x+2]) + sr := uint8((s + r + 1) / 2) + rq := uint8((r + q + 1) / 2) + qp := uint8((q + p + 1) / 2) + pa := uint8((p + a + 1) / 2) + srq := uint8((s + 2*r + q + 2) / 4) + rqp := uint8((r + 2*q + p + 2) / 4) + qpa := uint8((q + 2*p + a + 2) / 4) + pab := uint8((p + 2*a + b + 2) / 4) + abc := uint8((a + 2*b + c + 2) / 4) + bcd := uint8((b + 2*c + d + 2) / 4) + z.ybr[y+0][x+0] = pa + z.ybr[y+0][x+1] = pab + z.ybr[y+0][x+2] = abc + z.ybr[y+0][x+3] = bcd + z.ybr[y+1][x+0] = qp + z.ybr[y+1][x+1] = qpa + z.ybr[y+1][x+2] = pa + z.ybr[y+1][x+3] = pab + z.ybr[y+2][x+0] = rq + z.ybr[y+2][x+1] = rqp + z.ybr[y+2][x+2] = qp + z.ybr[y+2][x+3] = qpa + z.ybr[y+3][x+0] = sr + z.ybr[y+3][x+1] = srq + z.ybr[y+3][x+2] = rq + z.ybr[y+3][x+3] = rqp +} + +func predFunc4HU(z *Decoder, y, x int) { + s := int32(z.ybr[y+3][x-1]) + r := int32(z.ybr[y+2][x-1]) + q := int32(z.ybr[y+1][x-1]) + p := int32(z.ybr[y+0][x-1]) + pq := uint8((p + q + 1) / 2) + qr := uint8((q + r + 1) / 2) + rs := uint8((r + s + 1) / 2) + pqr := uint8((p + 2*q + r + 2) / 4) + qrs := uint8((q + 2*r + s + 2) / 4) + rss := uint8((r + 2*s + s + 2) / 4) + sss := uint8(s) + z.ybr[y+0][x+0] = pq + z.ybr[y+0][x+1] = pqr + z.ybr[y+0][x+2] = qr + z.ybr[y+0][x+3] = qrs + z.ybr[y+1][x+0] = qr + z.ybr[y+1][x+1] = qrs + z.ybr[y+1][x+2] = rs + z.ybr[y+1][x+3] = rss + z.ybr[y+2][x+0] = rs + z.ybr[y+2][x+1] = rss + z.ybr[y+2][x+2] = sss + z.ybr[y+2][x+3] = sss + z.ybr[y+3][x+0] = sss + z.ybr[y+3][x+1] = sss + z.ybr[y+3][x+2] = sss + z.ybr[y+3][x+3] = sss +} + +func predFunc8DC(z *Decoder, y, x int) { + sum := uint32(8) + for i := 0; i < 8; i++ { + sum += uint32(z.ybr[y-1][x+i]) + } + for j := 0; j < 8; j++ { + sum += uint32(z.ybr[y+j][x-1]) + } + avg := uint8(sum / 16) + for j := 0; j < 8; j++ { + for i := 0; i < 8; i++ { + z.ybr[y+j][x+i] = avg + } + } +} + +func predFunc8TM(z *Decoder, y, x int) { + delta0 := -int32(z.ybr[y-1][x-1]) + for j := 0; j < 8; j++ { + delta1 := delta0 + int32(z.ybr[y+j][x-1]) + for i := 0; i < 8; i++ { + delta2 := delta1 + int32(z.ybr[y-1][x+i]) + z.ybr[y+j][x+i] = uint8(clip(delta2, 0, 255)) + } + } +} + +func predFunc8VE(z *Decoder, y, x int) { + for j := 0; j < 8; j++ { + for i := 0; i < 8; i++ { + z.ybr[y+j][x+i] = z.ybr[y-1][x+i] + } + } +} + +func predFunc8HE(z *Decoder, y, x int) { + for j := 0; j < 8; j++ { + for i := 0; i < 8; i++ { + z.ybr[y+j][x+i] = z.ybr[y+j][x-1] + } + } +} + +func predFunc8DCTop(z *Decoder, y, x int) { + sum := uint32(4) + for j := 0; j < 8; j++ { + sum += uint32(z.ybr[y+j][x-1]) + } + avg := uint8(sum / 8) + for j := 0; j < 8; j++ { + for i := 0; i < 8; i++ { + z.ybr[y+j][x+i] = avg + } + } +} + +func predFunc8DCLeft(z *Decoder, y, x int) { + sum := uint32(4) + for i := 0; i < 8; i++ { + sum += uint32(z.ybr[y-1][x+i]) + } + avg := uint8(sum / 8) + for j := 0; j < 8; j++ { + for i := 0; i < 8; i++ { + z.ybr[y+j][x+i] = avg + } + } +} + +func predFunc8DCTopLeft(z *Decoder, y, x int) { + for j := 0; j < 8; j++ { + for i := 0; i < 8; i++ { + z.ybr[y+j][x+i] = 0x80 + } + } +} + +func predFunc16DC(z *Decoder, y, x int) { + sum := uint32(16) + for i := 0; i < 16; i++ { + sum += uint32(z.ybr[y-1][x+i]) + } + for j := 0; j < 16; j++ { + sum += uint32(z.ybr[y+j][x-1]) + } + avg := uint8(sum / 32) + for j := 0; j < 16; j++ { + for i := 0; i < 16; i++ { + z.ybr[y+j][x+i] = avg + } + } +} + +func predFunc16TM(z *Decoder, y, x int) { + delta0 := -int32(z.ybr[y-1][x-1]) + for j := 0; j < 16; j++ { + delta1 := delta0 + int32(z.ybr[y+j][x-1]) + for i := 0; i < 16; i++ { + delta2 := delta1 + int32(z.ybr[y-1][x+i]) + z.ybr[y+j][x+i] = uint8(clip(delta2, 0, 255)) + } + } +} + +func predFunc16VE(z *Decoder, y, x int) { + for j := 0; j < 16; j++ { + for i := 0; i < 16; i++ { + z.ybr[y+j][x+i] = z.ybr[y-1][x+i] + } + } +} + +func predFunc16HE(z *Decoder, y, x int) { + for j := 0; j < 16; j++ { + for i := 0; i < 16; i++ { + z.ybr[y+j][x+i] = z.ybr[y+j][x-1] + } + } +} + +func predFunc16DCTop(z *Decoder, y, x int) { + sum := uint32(8) + for j := 0; j < 16; j++ { + sum += uint32(z.ybr[y+j][x-1]) + } + avg := uint8(sum / 16) + for j := 0; j < 16; j++ { + for i := 0; i < 16; i++ { + z.ybr[y+j][x+i] = avg + } + } +} + +func predFunc16DCLeft(z *Decoder, y, x int) { + sum := uint32(8) + for i := 0; i < 16; i++ { + sum += uint32(z.ybr[y-1][x+i]) + } + avg := uint8(sum / 16) + for j := 0; j < 16; j++ { + for i := 0; i < 16; i++ { + z.ybr[y+j][x+i] = avg + } + } +} + +func predFunc16DCTopLeft(z *Decoder, y, x int) { + for j := 0; j < 16; j++ { + for i := 0; i < 16; i++ { + z.ybr[y+j][x+i] = 0x80 + } + } +} diff --git a/vendor/golang.org/x/image/vp8/quant.go b/vendor/golang.org/x/image/vp8/quant.go new file mode 100644 index 0000000..da43616 --- /dev/null +++ b/vendor/golang.org/x/image/vp8/quant.go @@ -0,0 +1,98 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package vp8 + +// This file implements parsing the quantization factors. + +// quant are DC/AC quantization factors. +type quant struct { + y1 [2]uint16 + y2 [2]uint16 + uv [2]uint16 +} + +// clip clips x to the range [min, max] inclusive. +func clip(x, min, max int32) int32 { + if x < min { + return min + } + if x > max { + return max + } + return x +} + +// parseQuant parses the quantization factors, as specified in section 9.6. +func (d *Decoder) parseQuant() { + baseQ0 := d.fp.readUint(uniformProb, 7) + dqy1DC := d.fp.readOptionalInt(uniformProb, 4) + const dqy1AC = 0 + dqy2DC := d.fp.readOptionalInt(uniformProb, 4) + dqy2AC := d.fp.readOptionalInt(uniformProb, 4) + dquvDC := d.fp.readOptionalInt(uniformProb, 4) + dquvAC := d.fp.readOptionalInt(uniformProb, 4) + for i := 0; i < nSegment; i++ { + q := int32(baseQ0) + if d.segmentHeader.useSegment { + if d.segmentHeader.relativeDelta { + q += int32(d.segmentHeader.quantizer[i]) + } else { + q = int32(d.segmentHeader.quantizer[i]) + } + } + d.quant[i].y1[0] = dequantTableDC[clip(q+dqy1DC, 0, 127)] + d.quant[i].y1[1] = dequantTableAC[clip(q+dqy1AC, 0, 127)] + d.quant[i].y2[0] = dequantTableDC[clip(q+dqy2DC, 0, 127)] * 2 + d.quant[i].y2[1] = dequantTableAC[clip(q+dqy2AC, 0, 127)] * 155 / 100 + if d.quant[i].y2[1] < 8 { + d.quant[i].y2[1] = 8 + } + // The 117 is not a typo. The dequant_init function in the spec's Reference + // Decoder Source Code (http://tools.ietf.org/html/rfc6386#section-9.6 Page 145) + // says to clamp the LHS value at 132, which is equal to dequantTableDC[117]. + d.quant[i].uv[0] = dequantTableDC[clip(q+dquvDC, 0, 117)] + d.quant[i].uv[1] = dequantTableAC[clip(q+dquvAC, 0, 127)] + } +} + +// The dequantization tables are specified in section 14.1. +var ( + dequantTableDC = [128]uint16{ + 4, 5, 6, 7, 8, 9, 10, 10, + 11, 12, 13, 14, 15, 16, 17, 17, + 18, 19, 20, 20, 21, 21, 22, 22, + 23, 23, 24, 25, 25, 26, 27, 28, + 29, 30, 31, 32, 33, 34, 35, 36, + 37, 37, 38, 39, 40, 41, 42, 43, + 44, 45, 46, 46, 47, 48, 49, 50, + 51, 52, 53, 54, 55, 56, 57, 58, + 59, 60, 61, 62, 63, 64, 65, 66, + 67, 68, 69, 70, 71, 72, 73, 74, + 75, 76, 76, 77, 78, 79, 80, 81, + 82, 83, 84, 85, 86, 87, 88, 89, + 91, 93, 95, 96, 98, 100, 101, 102, + 104, 106, 108, 110, 112, 114, 116, 118, + 122, 124, 126, 128, 130, 132, 134, 136, + 138, 140, 143, 145, 148, 151, 154, 157, + } + dequantTableAC = [128]uint16{ + 4, 5, 6, 7, 8, 9, 10, 11, + 12, 13, 14, 15, 16, 17, 18, 19, + 20, 21, 22, 23, 24, 25, 26, 27, + 28, 29, 30, 31, 32, 33, 34, 35, + 36, 37, 38, 39, 40, 41, 42, 43, + 44, 45, 46, 47, 48, 49, 50, 51, + 52, 53, 54, 55, 56, 57, 58, 60, + 62, 64, 66, 68, 70, 72, 74, 76, + 78, 80, 82, 84, 86, 88, 90, 92, + 94, 96, 98, 100, 102, 104, 106, 108, + 110, 112, 114, 116, 119, 122, 125, 128, + 131, 134, 137, 140, 143, 146, 149, 152, + 155, 158, 161, 164, 167, 170, 173, 177, + 181, 185, 189, 193, 197, 201, 205, 209, + 213, 217, 221, 225, 229, 234, 239, 245, + 249, 254, 259, 264, 269, 274, 279, 284, + } +) diff --git a/vendor/golang.org/x/image/vp8/reconstruct.go b/vendor/golang.org/x/image/vp8/reconstruct.go new file mode 100644 index 0000000..c1cc4b5 --- /dev/null +++ b/vendor/golang.org/x/image/vp8/reconstruct.go @@ -0,0 +1,442 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package vp8 + +// This file implements decoding DCT/WHT residual coefficients and +// reconstructing YCbCr data equal to predicted values plus residuals. +// +// There are 1*16*16 + 2*8*8 + 1*4*4 coefficients per macroblock: +// - 1*16*16 luma DCT coefficients, +// - 2*8*8 chroma DCT coefficients, and +// - 1*4*4 luma WHT coefficients. +// Coefficients are read in lots of 16, and the later coefficients in each lot +// are often zero. +// +// The YCbCr data consists of 1*16*16 luma values and 2*8*8 chroma values, +// plus previously decoded values along the top and left borders. The combined +// values are laid out as a [1+16+1+8][32]uint8 so that vertically adjacent +// samples are 32 bytes apart. In detail, the layout is: +// +// 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +// . . . . . . . a b b b b b b b b b b b b b b b b c c c c . . . . 0 +// . . . . . . . d Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y . . . . . . . . 1 +// . . . . . . . d Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y . . . . . . . . 2 +// . . . . . . . d Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y . . . . . . . . 3 +// . . . . . . . d Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y c c c c . . . . 4 +// . . . . . . . d Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y . . . . . . . . 5 +// . . . . . . . d Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y . . . . . . . . 6 +// . . . . . . . d Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y . . . . . . . . 7 +// . . . . . . . d Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y c c c c . . . . 8 +// . . . . . . . d Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y . . . . . . . . 9 +// . . . . . . . d Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y . . . . . . . . 10 +// . . . . . . . d Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y . . . . . . . . 11 +// . . . . . . . d Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y c c c c . . . . 12 +// . . . . . . . d Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y . . . . . . . . 13 +// . . . . . . . d Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y . . . . . . . . 14 +// . . . . . . . d Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y . . . . . . . . 15 +// . . . . . . . d Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y . . . . . . . . 16 +// . . . . . . . e f f f f f f f f . . . . . . . g h h h h h h h h 17 +// . . . . . . . i B B B B B B B B . . . . . . . j R R R R R R R R 18 +// . . . . . . . i B B B B B B B B . . . . . . . j R R R R R R R R 19 +// . . . . . . . i B B B B B B B B . . . . . . . j R R R R R R R R 20 +// . . . . . . . i B B B B B B B B . . . . . . . j R R R R R R R R 21 +// . . . . . . . i B B B B B B B B . . . . . . . j R R R R R R R R 22 +// . . . . . . . i B B B B B B B B . . . . . . . j R R R R R R R R 23 +// . . . . . . . i B B B B B B B B . . . . . . . j R R R R R R R R 24 +// . . . . . . . i B B B B B B B B . . . . . . . j R R R R R R R R 25 +// +// Y, B and R are the reconstructed luma (Y) and chroma (B, R) values. +// The Y values are predicted (either as one 16x16 region or 16 4x4 regions) +// based on the row above's Y values (some combination of {abc} or {dYC}) and +// the column left's Y values (either {ad} or {bY}). Similarly, B and R values +// are predicted on the row above and column left of their respective 8x8 +// region: {efi} for B, {ghj} for R. +// +// For uppermost macroblocks (i.e. those with mby == 0), the {abcefgh} values +// are initialized to 0x81. Otherwise, they are copied from the bottom row of +// the macroblock above. The {c} values are then duplicated from row 0 to rows +// 4, 8 and 12 of the ybr workspace. +// Similarly, for leftmost macroblocks (i.e. those with mbx == 0), the {adeigj} +// values are initialized to 0x7f. Otherwise, they are copied from the right +// column of the macroblock to the left. +// For the top-left macroblock (with mby == 0 && mbx == 0), {aeg} is 0x81. +// +// When moving from one macroblock to the next horizontally, the {adeigj} +// values can simply be copied from the workspace to itself, shifted by 8 or +// 16 columns. When moving from one macroblock to the next vertically, +// filtering can occur and hence the row values have to be copied from the +// post-filtered image instead of the pre-filtered workspace. + +const ( + bCoeffBase = 1*16*16 + 0*8*8 + rCoeffBase = 1*16*16 + 1*8*8 + whtCoeffBase = 1*16*16 + 2*8*8 +) + +const ( + ybrYX = 8 + ybrYY = 1 + ybrBX = 8 + ybrBY = 18 + ybrRX = 24 + ybrRY = 18 +) + +// prepareYBR prepares the {abcdefghij} elements of ybr. +func (d *Decoder) prepareYBR(mbx, mby int) { + if mbx == 0 { + for y := 0; y < 17; y++ { + d.ybr[y][7] = 0x81 + } + for y := 17; y < 26; y++ { + d.ybr[y][7] = 0x81 + d.ybr[y][23] = 0x81 + } + } else { + for y := 0; y < 17; y++ { + d.ybr[y][7] = d.ybr[y][7+16] + } + for y := 17; y < 26; y++ { + d.ybr[y][7] = d.ybr[y][15] + d.ybr[y][23] = d.ybr[y][31] + } + } + if mby == 0 { + for x := 7; x < 28; x++ { + d.ybr[0][x] = 0x7f + } + for x := 7; x < 16; x++ { + d.ybr[17][x] = 0x7f + } + for x := 23; x < 32; x++ { + d.ybr[17][x] = 0x7f + } + } else { + for i := 0; i < 16; i++ { + d.ybr[0][8+i] = d.img.Y[(16*mby-1)*d.img.YStride+16*mbx+i] + } + for i := 0; i < 8; i++ { + d.ybr[17][8+i] = d.img.Cb[(8*mby-1)*d.img.CStride+8*mbx+i] + } + for i := 0; i < 8; i++ { + d.ybr[17][24+i] = d.img.Cr[(8*mby-1)*d.img.CStride+8*mbx+i] + } + if mbx == d.mbw-1 { + for i := 16; i < 20; i++ { + d.ybr[0][8+i] = d.img.Y[(16*mby-1)*d.img.YStride+16*mbx+15] + } + } else { + for i := 16; i < 20; i++ { + d.ybr[0][8+i] = d.img.Y[(16*mby-1)*d.img.YStride+16*mbx+i] + } + } + } + for y := 4; y < 16; y += 4 { + d.ybr[y][24] = d.ybr[0][24] + d.ybr[y][25] = d.ybr[0][25] + d.ybr[y][26] = d.ybr[0][26] + d.ybr[y][27] = d.ybr[0][27] + } +} + +// btou converts a bool to a 0/1 value. +func btou(b bool) uint8 { + if b { + return 1 + } + return 0 +} + +// pack packs four 0/1 values into four bits of a uint32. +func pack(x [4]uint8, shift int) uint32 { + u := uint32(x[0])<<0 | uint32(x[1])<<1 | uint32(x[2])<<2 | uint32(x[3])<<3 + return u << uint(shift) +} + +// unpack unpacks four 0/1 values from a four-bit value. +var unpack = [16][4]uint8{ + {0, 0, 0, 0}, + {1, 0, 0, 0}, + {0, 1, 0, 0}, + {1, 1, 0, 0}, + {0, 0, 1, 0}, + {1, 0, 1, 0}, + {0, 1, 1, 0}, + {1, 1, 1, 0}, + {0, 0, 0, 1}, + {1, 0, 0, 1}, + {0, 1, 0, 1}, + {1, 1, 0, 1}, + {0, 0, 1, 1}, + {1, 0, 1, 1}, + {0, 1, 1, 1}, + {1, 1, 1, 1}, +} + +var ( + // The mapping from 4x4 region position to band is specified in section 13.3. + bands = [17]uint8{0, 1, 2, 3, 6, 4, 5, 6, 6, 6, 6, 6, 6, 6, 6, 7, 0} + // Category probabilties are specified in section 13.2. + // Decoding categories 1 and 2 are done inline. + cat3456 = [4][12]uint8{ + {173, 148, 140, 0, 0, 0, 0, 0, 0, 0, 0, 0}, + {176, 155, 140, 135, 0, 0, 0, 0, 0, 0, 0, 0}, + {180, 157, 141, 134, 130, 0, 0, 0, 0, 0, 0, 0}, + {254, 254, 243, 230, 196, 177, 153, 140, 133, 130, 129, 0}, + } + // The zigzag order is: + // 0 1 5 6 + // 2 4 7 12 + // 3 8 11 13 + // 9 10 14 15 + zigzag = [16]uint8{0, 1, 4, 8, 5, 2, 3, 6, 9, 12, 13, 10, 7, 11, 14, 15} +) + +// parseResiduals4 parses a 4x4 region of residual coefficients, as specified +// in section 13.3, and returns a 0/1 value indicating whether there was at +// least one non-zero coefficient. +// r is the partition to read bits from. +// plane and context describe which token probability table to use. context is +// either 0, 1 or 2, and equals how many of the macroblock left and macroblock +// above have non-zero coefficients. +// quant are the DC/AC quantization factors. +// skipFirstCoeff is whether the DC coefficient has already been parsed. +// coeffBase is the base index of d.coeff to write to. +func (d *Decoder) parseResiduals4(r *partition, plane int, context uint8, quant [2]uint16, skipFirstCoeff bool, coeffBase int) uint8 { + prob, n := &d.tokenProb[plane], 0 + if skipFirstCoeff { + n = 1 + } + p := prob[bands[n]][context] + if !r.readBit(p[0]) { + return 0 + } + for n != 16 { + n++ + if !r.readBit(p[1]) { + p = prob[bands[n]][0] + continue + } + var v uint32 + if !r.readBit(p[2]) { + v = 1 + p = prob[bands[n]][1] + } else { + if !r.readBit(p[3]) { + if !r.readBit(p[4]) { + v = 2 + } else { + v = 3 + r.readUint(p[5], 1) + } + } else if !r.readBit(p[6]) { + if !r.readBit(p[7]) { + // Category 1. + v = 5 + r.readUint(159, 1) + } else { + // Category 2. + v = 7 + 2*r.readUint(165, 1) + r.readUint(145, 1) + } + } else { + // Categories 3, 4, 5 or 6. + b1 := r.readUint(p[8], 1) + b0 := r.readUint(p[9+b1], 1) + cat := 2*b1 + b0 + tab := &cat3456[cat] + v = 0 + for i := 0; tab[i] != 0; i++ { + v *= 2 + v += r.readUint(tab[i], 1) + } + v += 3 + (8 << cat) + } + p = prob[bands[n]][2] + } + z := zigzag[n-1] + c := int32(v) * int32(quant[btou(z > 0)]) + if r.readBit(uniformProb) { + c = -c + } + d.coeff[coeffBase+int(z)] = int16(c) + if n == 16 || !r.readBit(p[0]) { + return 1 + } + } + return 1 +} + +// parseResiduals parses the residuals and returns whether inner loop filtering +// should be skipped for this macroblock. +func (d *Decoder) parseResiduals(mbx, mby int) (skip bool) { + partition := &d.op[mby&(d.nOP-1)] + plane := planeY1SansY2 + quant := &d.quant[d.segment] + + // Parse the DC coefficient of each 4x4 luma region. + if d.usePredY16 { + nz := d.parseResiduals4(partition, planeY2, d.leftMB.nzY16+d.upMB[mbx].nzY16, quant.y2, false, whtCoeffBase) + d.leftMB.nzY16 = nz + d.upMB[mbx].nzY16 = nz + d.inverseWHT16() + plane = planeY1WithY2 + } + + var ( + nzDC, nzAC [4]uint8 + nzDCMask, nzACMask uint32 + coeffBase int + ) + + // Parse the luma coefficients. + lnz := unpack[d.leftMB.nzMask&0x0f] + unz := unpack[d.upMB[mbx].nzMask&0x0f] + for y := 0; y < 4; y++ { + nz := lnz[y] + for x := 0; x < 4; x++ { + nz = d.parseResiduals4(partition, plane, nz+unz[x], quant.y1, d.usePredY16, coeffBase) + unz[x] = nz + nzAC[x] = nz + nzDC[x] = btou(d.coeff[coeffBase] != 0) + coeffBase += 16 + } + lnz[y] = nz + nzDCMask |= pack(nzDC, y*4) + nzACMask |= pack(nzAC, y*4) + } + lnzMask := pack(lnz, 0) + unzMask := pack(unz, 0) + + // Parse the chroma coefficients. + lnz = unpack[d.leftMB.nzMask>>4] + unz = unpack[d.upMB[mbx].nzMask>>4] + for c := 0; c < 4; c += 2 { + for y := 0; y < 2; y++ { + nz := lnz[y+c] + for x := 0; x < 2; x++ { + nz = d.parseResiduals4(partition, planeUV, nz+unz[x+c], quant.uv, false, coeffBase) + unz[x+c] = nz + nzAC[y*2+x] = nz + nzDC[y*2+x] = btou(d.coeff[coeffBase] != 0) + coeffBase += 16 + } + lnz[y+c] = nz + } + nzDCMask |= pack(nzDC, 16+c*2) + nzACMask |= pack(nzAC, 16+c*2) + } + lnzMask |= pack(lnz, 4) + unzMask |= pack(unz, 4) + + // Save decoder state. + d.leftMB.nzMask = uint8(lnzMask) + d.upMB[mbx].nzMask = uint8(unzMask) + d.nzDCMask = nzDCMask + d.nzACMask = nzACMask + + // Section 15.1 of the spec says that "Steps 2 and 4 [of the loop filter] + // are skipped... [if] there is no DCT coefficient coded for the whole + // macroblock." + return nzDCMask == 0 && nzACMask == 0 +} + +// reconstructMacroblock applies the predictor functions and adds the inverse- +// DCT transformed residuals to recover the YCbCr data. +func (d *Decoder) reconstructMacroblock(mbx, mby int) { + if d.usePredY16 { + p := checkTopLeftPred(mbx, mby, d.predY16) + predFunc16[p](d, 1, 8) + for j := 0; j < 4; j++ { + for i := 0; i < 4; i++ { + n := 4*j + i + y := 4*j + 1 + x := 4*i + 8 + mask := uint32(1) << uint(n) + if d.nzACMask&mask != 0 { + d.inverseDCT4(y, x, 16*n) + } else if d.nzDCMask&mask != 0 { + d.inverseDCT4DCOnly(y, x, 16*n) + } + } + } + } else { + for j := 0; j < 4; j++ { + for i := 0; i < 4; i++ { + n := 4*j + i + y := 4*j + 1 + x := 4*i + 8 + predFunc4[d.predY4[j][i]](d, y, x) + mask := uint32(1) << uint(n) + if d.nzACMask&mask != 0 { + d.inverseDCT4(y, x, 16*n) + } else if d.nzDCMask&mask != 0 { + d.inverseDCT4DCOnly(y, x, 16*n) + } + } + } + } + p := checkTopLeftPred(mbx, mby, d.predC8) + predFunc8[p](d, ybrBY, ybrBX) + if d.nzACMask&0x0f0000 != 0 { + d.inverseDCT8(ybrBY, ybrBX, bCoeffBase) + } else if d.nzDCMask&0x0f0000 != 0 { + d.inverseDCT8DCOnly(ybrBY, ybrBX, bCoeffBase) + } + predFunc8[p](d, ybrRY, ybrRX) + if d.nzACMask&0xf00000 != 0 { + d.inverseDCT8(ybrRY, ybrRX, rCoeffBase) + } else if d.nzDCMask&0xf00000 != 0 { + d.inverseDCT8DCOnly(ybrRY, ybrRX, rCoeffBase) + } +} + +// reconstruct reconstructs one macroblock and returns whether inner loop +// filtering should be skipped for it. +func (d *Decoder) reconstruct(mbx, mby int) (skip bool) { + if d.segmentHeader.updateMap { + if !d.fp.readBit(d.segmentHeader.prob[0]) { + d.segment = int(d.fp.readUint(d.segmentHeader.prob[1], 1)) + } else { + d.segment = int(d.fp.readUint(d.segmentHeader.prob[2], 1)) + 2 + } + } + if d.useSkipProb { + skip = d.fp.readBit(d.skipProb) + } + // Prepare the workspace. + for i := range d.coeff { + d.coeff[i] = 0 + } + d.prepareYBR(mbx, mby) + // Parse the predictor modes. + d.usePredY16 = d.fp.readBit(145) + if d.usePredY16 { + d.parsePredModeY16(mbx) + } else { + d.parsePredModeY4(mbx) + } + d.parsePredModeC8() + // Parse the residuals. + if !skip { + skip = d.parseResiduals(mbx, mby) + } else { + if d.usePredY16 { + d.leftMB.nzY16 = 0 + d.upMB[mbx].nzY16 = 0 + } + d.leftMB.nzMask = 0 + d.upMB[mbx].nzMask = 0 + d.nzDCMask = 0 + d.nzACMask = 0 + } + // Reconstruct the YCbCr data and copy it to the image. + d.reconstructMacroblock(mbx, mby) + for i, y := (mby*d.img.YStride+mbx)*16, 0; y < 16; i, y = i+d.img.YStride, y+1 { + copy(d.img.Y[i:i+16], d.ybr[ybrYY+y][ybrYX:ybrYX+16]) + } + for i, y := (mby*d.img.CStride+mbx)*8, 0; y < 8; i, y = i+d.img.CStride, y+1 { + copy(d.img.Cb[i:i+8], d.ybr[ybrBY+y][ybrBX:ybrBX+8]) + copy(d.img.Cr[i:i+8], d.ybr[ybrRY+y][ybrRX:ybrRX+8]) + } + return skip +} diff --git a/vendor/golang.org/x/image/vp8/token.go b/vendor/golang.org/x/image/vp8/token.go new file mode 100644 index 0000000..da99cf0 --- /dev/null +++ b/vendor/golang.org/x/image/vp8/token.go @@ -0,0 +1,381 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package vp8 + +// This file contains token probabilities for decoding DCT/WHT coefficients, as +// specified in chapter 13. + +func (d *Decoder) parseTokenProb() { + for i := range d.tokenProb { + for j := range d.tokenProb[i] { + for k := range d.tokenProb[i][j] { + for l := range d.tokenProb[i][j][k] { + if d.fp.readBit(tokenProbUpdateProb[i][j][k][l]) { + d.tokenProb[i][j][k][l] = uint8(d.fp.readUint(uniformProb, 8)) + } + } + } + } + } +} + +// The plane enumeration is specified in section 13.3. +const ( + planeY1WithY2 = iota + planeY2 + planeUV + planeY1SansY2 + nPlane +) + +const ( + nBand = 8 + nContext = 3 + nProb = 11 +) + +// Token probability update probabilities are specified in section 13.4. +var tokenProbUpdateProb = [nPlane][nBand][nContext][nProb]uint8{ + { + { + {255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + {255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + {255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + }, + { + {176, 246, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + {223, 241, 252, 255, 255, 255, 255, 255, 255, 255, 255}, + {249, 253, 253, 255, 255, 255, 255, 255, 255, 255, 255}, + }, + { + {255, 244, 252, 255, 255, 255, 255, 255, 255, 255, 255}, + {234, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255}, + {253, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + }, + { + {255, 246, 254, 255, 255, 255, 255, 255, 255, 255, 255}, + {239, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255}, + {254, 255, 254, 255, 255, 255, 255, 255, 255, 255, 255}, + }, + { + {255, 248, 254, 255, 255, 255, 255, 255, 255, 255, 255}, + {251, 255, 254, 255, 255, 255, 255, 255, 255, 255, 255}, + {255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + }, + { + {255, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255}, + {251, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255}, + {254, 255, 254, 255, 255, 255, 255, 255, 255, 255, 255}, + }, + { + {255, 254, 253, 255, 254, 255, 255, 255, 255, 255, 255}, + {250, 255, 254, 255, 254, 255, 255, 255, 255, 255, 255}, + {254, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + }, + { + {255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + {255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + {255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + }, + }, + { + { + {217, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + {225, 252, 241, 253, 255, 255, 254, 255, 255, 255, 255}, + {234, 250, 241, 250, 253, 255, 253, 254, 255, 255, 255}, + }, + { + {255, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + {223, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255}, + {238, 253, 254, 254, 255, 255, 255, 255, 255, 255, 255}, + }, + { + {255, 248, 254, 255, 255, 255, 255, 255, 255, 255, 255}, + {249, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + {255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + }, + { + {255, 253, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + {247, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + {255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + }, + { + {255, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255}, + {252, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + {255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + }, + { + {255, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255}, + {253, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + {255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + }, + { + {255, 254, 253, 255, 255, 255, 255, 255, 255, 255, 255}, + {250, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + {254, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + }, + { + {255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + {255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + {255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + }, + }, + { + { + {186, 251, 250, 255, 255, 255, 255, 255, 255, 255, 255}, + {234, 251, 244, 254, 255, 255, 255, 255, 255, 255, 255}, + {251, 251, 243, 253, 254, 255, 254, 255, 255, 255, 255}, + }, + { + {255, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255}, + {236, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255}, + {251, 253, 253, 254, 254, 255, 255, 255, 255, 255, 255}, + }, + { + {255, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255}, + {254, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255}, + {255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + }, + { + {255, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + {254, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + {254, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + }, + { + {255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + {254, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + {255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + }, + { + {255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + {255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + {255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + }, + { + {255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + {255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + {255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + }, + { + {255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + {255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + {255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + }, + }, + { + { + {248, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + {250, 254, 252, 254, 255, 255, 255, 255, 255, 255, 255}, + {248, 254, 249, 253, 255, 255, 255, 255, 255, 255, 255}, + }, + { + {255, 253, 253, 255, 255, 255, 255, 255, 255, 255, 255}, + {246, 253, 253, 255, 255, 255, 255, 255, 255, 255, 255}, + {252, 254, 251, 254, 254, 255, 255, 255, 255, 255, 255}, + }, + { + {255, 254, 252, 255, 255, 255, 255, 255, 255, 255, 255}, + {248, 254, 253, 255, 255, 255, 255, 255, 255, 255, 255}, + {253, 255, 254, 254, 255, 255, 255, 255, 255, 255, 255}, + }, + { + {255, 251, 254, 255, 255, 255, 255, 255, 255, 255, 255}, + {245, 251, 254, 255, 255, 255, 255, 255, 255, 255, 255}, + {253, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255}, + }, + { + {255, 251, 253, 255, 255, 255, 255, 255, 255, 255, 255}, + {252, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255}, + {255, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + }, + { + {255, 252, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + {249, 255, 254, 255, 255, 255, 255, 255, 255, 255, 255}, + {255, 255, 254, 255, 255, 255, 255, 255, 255, 255, 255}, + }, + { + {255, 255, 253, 255, 255, 255, 255, 255, 255, 255, 255}, + {250, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + {255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + }, + { + {255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + {254, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + {255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}, + }, + }, +} + +// Default token probabilities are specified in section 13.5. +var defaultTokenProb = [nPlane][nBand][nContext][nProb]uint8{ + { + { + {128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128}, + {128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128}, + {128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128}, + }, + { + {253, 136, 254, 255, 228, 219, 128, 128, 128, 128, 128}, + {189, 129, 242, 255, 227, 213, 255, 219, 128, 128, 128}, + {106, 126, 227, 252, 214, 209, 255, 255, 128, 128, 128}, + }, + { + {1, 98, 248, 255, 236, 226, 255, 255, 128, 128, 128}, + {181, 133, 238, 254, 221, 234, 255, 154, 128, 128, 128}, + {78, 134, 202, 247, 198, 180, 255, 219, 128, 128, 128}, + }, + { + {1, 185, 249, 255, 243, 255, 128, 128, 128, 128, 128}, + {184, 150, 247, 255, 236, 224, 128, 128, 128, 128, 128}, + {77, 110, 216, 255, 236, 230, 128, 128, 128, 128, 128}, + }, + { + {1, 101, 251, 255, 241, 255, 128, 128, 128, 128, 128}, + {170, 139, 241, 252, 236, 209, 255, 255, 128, 128, 128}, + {37, 116, 196, 243, 228, 255, 255, 255, 128, 128, 128}, + }, + { + {1, 204, 254, 255, 245, 255, 128, 128, 128, 128, 128}, + {207, 160, 250, 255, 238, 128, 128, 128, 128, 128, 128}, + {102, 103, 231, 255, 211, 171, 128, 128, 128, 128, 128}, + }, + { + {1, 152, 252, 255, 240, 255, 128, 128, 128, 128, 128}, + {177, 135, 243, 255, 234, 225, 128, 128, 128, 128, 128}, + {80, 129, 211, 255, 194, 224, 128, 128, 128, 128, 128}, + }, + { + {1, 1, 255, 128, 128, 128, 128, 128, 128, 128, 128}, + {246, 1, 255, 128, 128, 128, 128, 128, 128, 128, 128}, + {255, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128}, + }, + }, + { + { + {198, 35, 237, 223, 193, 187, 162, 160, 145, 155, 62}, + {131, 45, 198, 221, 172, 176, 220, 157, 252, 221, 1}, + {68, 47, 146, 208, 149, 167, 221, 162, 255, 223, 128}, + }, + { + {1, 149, 241, 255, 221, 224, 255, 255, 128, 128, 128}, + {184, 141, 234, 253, 222, 220, 255, 199, 128, 128, 128}, + {81, 99, 181, 242, 176, 190, 249, 202, 255, 255, 128}, + }, + { + {1, 129, 232, 253, 214, 197, 242, 196, 255, 255, 128}, + {99, 121, 210, 250, 201, 198, 255, 202, 128, 128, 128}, + {23, 91, 163, 242, 170, 187, 247, 210, 255, 255, 128}, + }, + { + {1, 200, 246, 255, 234, 255, 128, 128, 128, 128, 128}, + {109, 178, 241, 255, 231, 245, 255, 255, 128, 128, 128}, + {44, 130, 201, 253, 205, 192, 255, 255, 128, 128, 128}, + }, + { + {1, 132, 239, 251, 219, 209, 255, 165, 128, 128, 128}, + {94, 136, 225, 251, 218, 190, 255, 255, 128, 128, 128}, + {22, 100, 174, 245, 186, 161, 255, 199, 128, 128, 128}, + }, + { + {1, 182, 249, 255, 232, 235, 128, 128, 128, 128, 128}, + {124, 143, 241, 255, 227, 234, 128, 128, 128, 128, 128}, + {35, 77, 181, 251, 193, 211, 255, 205, 128, 128, 128}, + }, + { + {1, 157, 247, 255, 236, 231, 255, 255, 128, 128, 128}, + {121, 141, 235, 255, 225, 227, 255, 255, 128, 128, 128}, + {45, 99, 188, 251, 195, 217, 255, 224, 128, 128, 128}, + }, + { + {1, 1, 251, 255, 213, 255, 128, 128, 128, 128, 128}, + {203, 1, 248, 255, 255, 128, 128, 128, 128, 128, 128}, + {137, 1, 177, 255, 224, 255, 128, 128, 128, 128, 128}, + }, + }, + { + { + {253, 9, 248, 251, 207, 208, 255, 192, 128, 128, 128}, + {175, 13, 224, 243, 193, 185, 249, 198, 255, 255, 128}, + {73, 17, 171, 221, 161, 179, 236, 167, 255, 234, 128}, + }, + { + {1, 95, 247, 253, 212, 183, 255, 255, 128, 128, 128}, + {239, 90, 244, 250, 211, 209, 255, 255, 128, 128, 128}, + {155, 77, 195, 248, 188, 195, 255, 255, 128, 128, 128}, + }, + { + {1, 24, 239, 251, 218, 219, 255, 205, 128, 128, 128}, + {201, 51, 219, 255, 196, 186, 128, 128, 128, 128, 128}, + {69, 46, 190, 239, 201, 218, 255, 228, 128, 128, 128}, + }, + { + {1, 191, 251, 255, 255, 128, 128, 128, 128, 128, 128}, + {223, 165, 249, 255, 213, 255, 128, 128, 128, 128, 128}, + {141, 124, 248, 255, 255, 128, 128, 128, 128, 128, 128}, + }, + { + {1, 16, 248, 255, 255, 128, 128, 128, 128, 128, 128}, + {190, 36, 230, 255, 236, 255, 128, 128, 128, 128, 128}, + {149, 1, 255, 128, 128, 128, 128, 128, 128, 128, 128}, + }, + { + {1, 226, 255, 128, 128, 128, 128, 128, 128, 128, 128}, + {247, 192, 255, 128, 128, 128, 128, 128, 128, 128, 128}, + {240, 128, 255, 128, 128, 128, 128, 128, 128, 128, 128}, + }, + { + {1, 134, 252, 255, 255, 128, 128, 128, 128, 128, 128}, + {213, 62, 250, 255, 255, 128, 128, 128, 128, 128, 128}, + {55, 93, 255, 128, 128, 128, 128, 128, 128, 128, 128}, + }, + { + {128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128}, + {128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128}, + {128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128}, + }, + }, + { + { + {202, 24, 213, 235, 186, 191, 220, 160, 240, 175, 255}, + {126, 38, 182, 232, 169, 184, 228, 174, 255, 187, 128}, + {61, 46, 138, 219, 151, 178, 240, 170, 255, 216, 128}, + }, + { + {1, 112, 230, 250, 199, 191, 247, 159, 255, 255, 128}, + {166, 109, 228, 252, 211, 215, 255, 174, 128, 128, 128}, + {39, 77, 162, 232, 172, 180, 245, 178, 255, 255, 128}, + }, + { + {1, 52, 220, 246, 198, 199, 249, 220, 255, 255, 128}, + {124, 74, 191, 243, 183, 193, 250, 221, 255, 255, 128}, + {24, 71, 130, 219, 154, 170, 243, 182, 255, 255, 128}, + }, + { + {1, 182, 225, 249, 219, 240, 255, 224, 128, 128, 128}, + {149, 150, 226, 252, 216, 205, 255, 171, 128, 128, 128}, + {28, 108, 170, 242, 183, 194, 254, 223, 255, 255, 128}, + }, + { + {1, 81, 230, 252, 204, 203, 255, 192, 128, 128, 128}, + {123, 102, 209, 247, 188, 196, 255, 233, 128, 128, 128}, + {20, 95, 153, 243, 164, 173, 255, 203, 128, 128, 128}, + }, + { + {1, 222, 248, 255, 216, 213, 128, 128, 128, 128, 128}, + {168, 175, 246, 252, 235, 205, 255, 255, 128, 128, 128}, + {47, 116, 215, 255, 211, 212, 255, 255, 128, 128, 128}, + }, + { + {1, 121, 236, 253, 212, 214, 255, 255, 128, 128, 128}, + {141, 84, 213, 252, 201, 202, 255, 219, 128, 128, 128}, + {42, 80, 160, 240, 162, 185, 255, 205, 128, 128, 128}, + }, + { + {1, 1, 255, 128, 128, 128, 128, 128, 128, 128, 128}, + {244, 1, 255, 128, 128, 128, 128, 128, 128, 128, 128}, + {238, 1, 255, 128, 128, 128, 128, 128, 128, 128, 128}, + }, + }, +} diff --git a/vendor/golang.org/x/image/vp8l/decode.go b/vendor/golang.org/x/image/vp8l/decode.go new file mode 100644 index 0000000..4319487 --- /dev/null +++ b/vendor/golang.org/x/image/vp8l/decode.go @@ -0,0 +1,603 @@ +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package vp8l implements a decoder for the VP8L lossless image format. +// +// The VP8L specification is at: +// https://developers.google.com/speed/webp/docs/riff_container +package vp8l // import "golang.org/x/image/vp8l" + +import ( + "bufio" + "errors" + "image" + "image/color" + "io" +) + +var ( + errInvalidCodeLengths = errors.New("vp8l: invalid code lengths") + errInvalidHuffmanTree = errors.New("vp8l: invalid Huffman tree") +) + +// colorCacheMultiplier is the multiplier used for the color cache hash +// function, specified in section 4.2.3. +const colorCacheMultiplier = 0x1e35a7bd + +// distanceMapTable is the look-up table for distanceMap. +var distanceMapTable = [120]uint8{ + 0x18, 0x07, 0x17, 0x19, 0x28, 0x06, 0x27, 0x29, 0x16, 0x1a, + 0x26, 0x2a, 0x38, 0x05, 0x37, 0x39, 0x15, 0x1b, 0x36, 0x3a, + 0x25, 0x2b, 0x48, 0x04, 0x47, 0x49, 0x14, 0x1c, 0x35, 0x3b, + 0x46, 0x4a, 0x24, 0x2c, 0x58, 0x45, 0x4b, 0x34, 0x3c, 0x03, + 0x57, 0x59, 0x13, 0x1d, 0x56, 0x5a, 0x23, 0x2d, 0x44, 0x4c, + 0x55, 0x5b, 0x33, 0x3d, 0x68, 0x02, 0x67, 0x69, 0x12, 0x1e, + 0x66, 0x6a, 0x22, 0x2e, 0x54, 0x5c, 0x43, 0x4d, 0x65, 0x6b, + 0x32, 0x3e, 0x78, 0x01, 0x77, 0x79, 0x53, 0x5d, 0x11, 0x1f, + 0x64, 0x6c, 0x42, 0x4e, 0x76, 0x7a, 0x21, 0x2f, 0x75, 0x7b, + 0x31, 0x3f, 0x63, 0x6d, 0x52, 0x5e, 0x00, 0x74, 0x7c, 0x41, + 0x4f, 0x10, 0x20, 0x62, 0x6e, 0x30, 0x73, 0x7d, 0x51, 0x5f, + 0x40, 0x72, 0x7e, 0x61, 0x6f, 0x50, 0x71, 0x7f, 0x60, 0x70, +} + +// distanceMap maps a LZ77 backwards reference distance to a two-dimensional +// pixel offset, specified in section 4.2.2. +func distanceMap(w int32, code uint32) int32 { + if int32(code) > int32(len(distanceMapTable)) { + return int32(code) - int32(len(distanceMapTable)) + } + distCode := int32(distanceMapTable[code-1]) + yOffset := distCode >> 4 + xOffset := 8 - distCode&0xf + if d := yOffset*w + xOffset; d >= 1 { + return d + } + return 1 +} + +// decoder holds the bit-stream for a VP8L image. +type decoder struct { + r io.ByteReader + bits uint32 + nBits uint32 +} + +// read reads the next n bits from the decoder's bit-stream. +func (d *decoder) read(n uint32) (uint32, error) { + for d.nBits < n { + c, err := d.r.ReadByte() + if err != nil { + if err == io.EOF { + err = io.ErrUnexpectedEOF + } + return 0, err + } + d.bits |= uint32(c) << d.nBits + d.nBits += 8 + } + u := d.bits & (1<>= n + d.nBits -= n + return u, nil +} + +// decodeTransform decodes the next transform and the width of the image after +// transformation (or equivalently, before inverse transformation), specified +// in section 3. +func (d *decoder) decodeTransform(w int32, h int32) (t transform, newWidth int32, err error) { + t.oldWidth = w + t.transformType, err = d.read(2) + if err != nil { + return transform{}, 0, err + } + switch t.transformType { + case transformTypePredictor, transformTypeCrossColor: + t.bits, err = d.read(3) + if err != nil { + return transform{}, 0, err + } + t.bits += 2 + t.pix, err = d.decodePix(nTiles(w, t.bits), nTiles(h, t.bits), 0, false) + if err != nil { + return transform{}, 0, err + } + case transformTypeSubtractGreen: + // No-op. + case transformTypeColorIndexing: + nColors, err := d.read(8) + if err != nil { + return transform{}, 0, err + } + nColors++ + t.bits = 0 + switch { + case nColors <= 2: + t.bits = 3 + case nColors <= 4: + t.bits = 2 + case nColors <= 16: + t.bits = 1 + } + w = nTiles(w, t.bits) + pix, err := d.decodePix(int32(nColors), 1, 4*256, false) + if err != nil { + return transform{}, 0, err + } + for p := 4; p < len(pix); p += 4 { + pix[p+0] += pix[p-4] + pix[p+1] += pix[p-3] + pix[p+2] += pix[p-2] + pix[p+3] += pix[p-1] + } + // The spec says that "if the index is equal or larger than color_table_size, + // the argb color value should be set to 0x00000000 (transparent black)." + // We re-slice up to 256 4-byte pixels. + t.pix = pix[:4*256] + } + return t, w, nil +} + +// repeatsCodeLength is the minimum code length for repeated codes. +const repeatsCodeLength = 16 + +// These magic numbers are specified at the end of section 5.2.2. +// The 3-length arrays apply to code lengths >= repeatsCodeLength. +var ( + codeLengthCodeOrder = [19]uint8{ + 17, 18, 0, 1, 2, 3, 4, 5, 16, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, + } + repeatBits = [3]uint8{2, 3, 7} + repeatOffsets = [3]uint8{3, 3, 11} +) + +// decodeCodeLengths decodes a Huffman tree's code lengths which are themselves +// encoded via a Huffman tree, specified in section 5.2.2. +func (d *decoder) decodeCodeLengths(dst []uint32, codeLengthCodeLengths []uint32) error { + h := hTree{} + if err := h.build(codeLengthCodeLengths); err != nil { + return err + } + + maxSymbol := len(dst) + useLength, err := d.read(1) + if err != nil { + return err + } + if useLength != 0 { + n, err := d.read(3) + if err != nil { + return err + } + n = 2 + 2*n + ms, err := d.read(n) + if err != nil { + return err + } + maxSymbol = int(ms) + 2 + if maxSymbol > len(dst) { + return errInvalidCodeLengths + } + } + + // The spec says that "if code 16 [meaning repeat] is used before + // a non-zero value has been emitted, a value of 8 is repeated." + prevCodeLength := uint32(8) + + for symbol := 0; symbol < len(dst); { + if maxSymbol == 0 { + break + } + maxSymbol-- + codeLength, err := h.next(d) + if err != nil { + return err + } + if codeLength < repeatsCodeLength { + dst[symbol] = codeLength + symbol++ + if codeLength != 0 { + prevCodeLength = codeLength + } + continue + } + + repeat, err := d.read(uint32(repeatBits[codeLength-repeatsCodeLength])) + if err != nil { + return err + } + repeat += uint32(repeatOffsets[codeLength-repeatsCodeLength]) + if symbol+int(repeat) > len(dst) { + return errInvalidCodeLengths + } + // A code length of 16 repeats the previous non-zero code. + // A code length of 17 or 18 repeats zeroes. + cl := uint32(0) + if codeLength == 16 { + cl = prevCodeLength + } + for ; repeat > 0; repeat-- { + dst[symbol] = cl + symbol++ + } + } + return nil +} + +// decodeHuffmanTree decodes a Huffman tree into h. +func (d *decoder) decodeHuffmanTree(h *hTree, alphabetSize uint32) error { + useSimple, err := d.read(1) + if err != nil { + return err + } + if useSimple != 0 { + nSymbols, err := d.read(1) + if err != nil { + return err + } + nSymbols++ + firstSymbolLengthCode, err := d.read(1) + if err != nil { + return err + } + firstSymbolLengthCode = 7*firstSymbolLengthCode + 1 + var symbols [2]uint32 + symbols[0], err = d.read(firstSymbolLengthCode) + if err != nil { + return err + } + if nSymbols == 2 { + symbols[1], err = d.read(8) + if err != nil { + return err + } + } + return h.buildSimple(nSymbols, symbols, alphabetSize) + } + + nCodes, err := d.read(4) + if err != nil { + return err + } + nCodes += 4 + if int(nCodes) > len(codeLengthCodeOrder) { + return errInvalidHuffmanTree + } + codeLengthCodeLengths := [len(codeLengthCodeOrder)]uint32{} + for i := uint32(0); i < nCodes; i++ { + codeLengthCodeLengths[codeLengthCodeOrder[i]], err = d.read(3) + if err != nil { + return err + } + } + codeLengths := make([]uint32, alphabetSize) + if err = d.decodeCodeLengths(codeLengths, codeLengthCodeLengths[:]); err != nil { + return err + } + return h.build(codeLengths) +} + +const ( + huffGreen = 0 + huffRed = 1 + huffBlue = 2 + huffAlpha = 3 + huffDistance = 4 + nHuff = 5 +) + +// hGroup is an array of 5 Huffman trees. +type hGroup [nHuff]hTree + +// decodeHuffmanGroups decodes the one or more hGroups used to decode the pixel +// data. If one hGroup is used for the entire image, then hPix and hBits will +// be zero. If more than one hGroup is used, then hPix contains the meta-image +// that maps tiles to hGroup index, and hBits contains the log-2 tile size. +func (d *decoder) decodeHuffmanGroups(w int32, h int32, topLevel bool, ccBits uint32) ( + hGroups []hGroup, hPix []byte, hBits uint32, err error) { + + maxHGroupIndex := 0 + if topLevel { + useMeta, err := d.read(1) + if err != nil { + return nil, nil, 0, err + } + if useMeta != 0 { + hBits, err = d.read(3) + if err != nil { + return nil, nil, 0, err + } + hBits += 2 + hPix, err = d.decodePix(nTiles(w, hBits), nTiles(h, hBits), 0, false) + if err != nil { + return nil, nil, 0, err + } + for p := 0; p < len(hPix); p += 4 { + i := int(hPix[p])<<8 | int(hPix[p+1]) + if maxHGroupIndex < i { + maxHGroupIndex = i + } + } + } + } + hGroups = make([]hGroup, maxHGroupIndex+1) + for i := range hGroups { + for j, alphabetSize := range alphabetSizes { + if j == 0 && ccBits > 0 { + alphabetSize += 1 << ccBits + } + if err := d.decodeHuffmanTree(&hGroups[i][j], alphabetSize); err != nil { + return nil, nil, 0, err + } + } + } + return hGroups, hPix, hBits, nil +} + +const ( + nLiteralCodes = 256 + nLengthCodes = 24 + nDistanceCodes = 40 +) + +var alphabetSizes = [nHuff]uint32{ + nLiteralCodes + nLengthCodes, + nLiteralCodes, + nLiteralCodes, + nLiteralCodes, + nDistanceCodes, +} + +// decodePix decodes pixel data, specified in section 5.2.2. +func (d *decoder) decodePix(w int32, h int32, minCap int32, topLevel bool) ([]byte, error) { + // Decode the color cache parameters. + ccBits, ccShift, ccEntries := uint32(0), uint32(0), ([]uint32)(nil) + useColorCache, err := d.read(1) + if err != nil { + return nil, err + } + if useColorCache != 0 { + ccBits, err = d.read(4) + if err != nil { + return nil, err + } + if ccBits < 1 || 11 < ccBits { + return nil, errors.New("vp8l: invalid color cache parameters") + } + ccShift = 32 - ccBits + ccEntries = make([]uint32, 1<>hBits) + (x >> hBits)) + hg = &hGroups[uint32(hPix[i])<<8|uint32(hPix[i+1])] + } + + green, err := hg[huffGreen].next(d) + if err != nil { + return nil, err + } + switch { + case green < nLiteralCodes: + // We have a literal pixel. + red, err := hg[huffRed].next(d) + if err != nil { + return nil, err + } + blue, err := hg[huffBlue].next(d) + if err != nil { + return nil, err + } + alpha, err := hg[huffAlpha].next(d) + if err != nil { + return nil, err + } + pix[p+0] = uint8(red) + pix[p+1] = uint8(green) + pix[p+2] = uint8(blue) + pix[p+3] = uint8(alpha) + p += 4 + + x++ + if x == w { + x, y = 0, y+1 + } + lookupHG = hMask != 0 && x&hMask == 0 + + case green < nLiteralCodes+nLengthCodes: + // We have a LZ77 backwards reference. + length, err := d.lz77Param(green - nLiteralCodes) + if err != nil { + return nil, err + } + distSym, err := hg[huffDistance].next(d) + if err != nil { + return nil, err + } + distCode, err := d.lz77Param(distSym) + if err != nil { + return nil, err + } + dist := distanceMap(w, distCode) + pEnd := p + 4*int(length) + q := p - 4*int(dist) + qEnd := pEnd - 4*int(dist) + if p < 0 || len(pix) < pEnd || q < 0 || len(pix) < qEnd { + return nil, errors.New("vp8l: invalid LZ77 parameters") + } + for ; p < pEnd; p, q = p+1, q+1 { + pix[p] = pix[q] + } + + x += int32(length) + for x >= w { + x, y = x-w, y+1 + } + lookupHG = hMask != 0 + + default: + // We have a color cache lookup. First, insert previous pixels + // into the cache. Note that VP8L assumes ARGB order, but the + // Go image.RGBA type is in RGBA order. + for ; cachedP < p; cachedP += 4 { + argb := uint32(pix[cachedP+0])<<16 | + uint32(pix[cachedP+1])<<8 | + uint32(pix[cachedP+2])<<0 | + uint32(pix[cachedP+3])<<24 + ccEntries[(argb*colorCacheMultiplier)>>ccShift] = argb + } + green -= nLiteralCodes + nLengthCodes + if int(green) >= len(ccEntries) { + return nil, errors.New("vp8l: invalid color cache index") + } + argb := ccEntries[green] + pix[p+0] = uint8(argb >> 16) + pix[p+1] = uint8(argb >> 8) + pix[p+2] = uint8(argb >> 0) + pix[p+3] = uint8(argb >> 24) + p += 4 + + x++ + if x == w { + x, y = 0, y+1 + } + lookupHG = hMask != 0 && x&hMask == 0 + } + } + return pix, nil +} + +// lz77Param returns the next LZ77 parameter: a length or a distance, specified +// in section 4.2.2. +func (d *decoder) lz77Param(symbol uint32) (uint32, error) { + if symbol < 4 { + return symbol + 1, nil + } + extraBits := (symbol - 2) >> 1 + offset := (2 + symbol&1) << extraBits + n, err := d.read(extraBits) + if err != nil { + return 0, err + } + return offset + n + 1, nil +} + +// decodeHeader decodes the VP8L header from r. +func decodeHeader(r io.Reader) (d *decoder, w int32, h int32, err error) { + rr, ok := r.(io.ByteReader) + if !ok { + rr = bufio.NewReader(r) + } + d = &decoder{r: rr} + magic, err := d.read(8) + if err != nil { + return nil, 0, 0, err + } + if magic != 0x2f { + return nil, 0, 0, errors.New("vp8l: invalid header") + } + width, err := d.read(14) + if err != nil { + return nil, 0, 0, err + } + width++ + height, err := d.read(14) + if err != nil { + return nil, 0, 0, err + } + height++ + _, err = d.read(1) // Read and ignore the hasAlpha hint. + if err != nil { + return nil, 0, 0, err + } + version, err := d.read(3) + if err != nil { + return nil, 0, 0, err + } + if version != 0 { + return nil, 0, 0, errors.New("vp8l: invalid version") + } + return d, int32(width), int32(height), nil +} + +// DecodeConfig decodes the color model and dimensions of a VP8L image from r. +func DecodeConfig(r io.Reader) (image.Config, error) { + _, w, h, err := decodeHeader(r) + if err != nil { + return image.Config{}, err + } + return image.Config{ + ColorModel: color.NRGBAModel, + Width: int(w), + Height: int(h), + }, nil +} + +// Decode decodes a VP8L image from r. +func Decode(r io.Reader) (image.Image, error) { + d, w, h, err := decodeHeader(r) + if err != nil { + return nil, err + } + // Decode the transforms. + var ( + nTransforms int + transforms [nTransformTypes]transform + transformsSeen [nTransformTypes]bool + originalW = w + ) + for { + more, err := d.read(1) + if err != nil { + return nil, err + } + if more == 0 { + break + } + var t transform + t, w, err = d.decodeTransform(w, h) + if err != nil { + return nil, err + } + if transformsSeen[t.transformType] { + return nil, errors.New("vp8l: repeated transform") + } + transformsSeen[t.transformType] = true + transforms[nTransforms] = t + nTransforms++ + } + // Decode the transformed pixels. + pix, err := d.decodePix(w, h, 0, true) + if err != nil { + return nil, err + } + // Apply the inverse transformations. + for i := nTransforms - 1; i >= 0; i-- { + t := &transforms[i] + pix = inverseTransforms[t.transformType](t, pix, h) + } + return &image.NRGBA{ + Pix: pix, + Stride: 4 * int(originalW), + Rect: image.Rect(0, 0, int(originalW), int(h)), + }, nil +} diff --git a/vendor/golang.org/x/image/vp8l/huffman.go b/vendor/golang.org/x/image/vp8l/huffman.go new file mode 100644 index 0000000..36368a8 --- /dev/null +++ b/vendor/golang.org/x/image/vp8l/huffman.go @@ -0,0 +1,245 @@ +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package vp8l + +import ( + "io" +) + +// reverseBits reverses the bits in a byte. +var reverseBits = [256]uint8{ + 0x00, 0x80, 0x40, 0xc0, 0x20, 0xa0, 0x60, 0xe0, 0x10, 0x90, 0x50, 0xd0, 0x30, 0xb0, 0x70, 0xf0, + 0x08, 0x88, 0x48, 0xc8, 0x28, 0xa8, 0x68, 0xe8, 0x18, 0x98, 0x58, 0xd8, 0x38, 0xb8, 0x78, 0xf8, + 0x04, 0x84, 0x44, 0xc4, 0x24, 0xa4, 0x64, 0xe4, 0x14, 0x94, 0x54, 0xd4, 0x34, 0xb4, 0x74, 0xf4, + 0x0c, 0x8c, 0x4c, 0xcc, 0x2c, 0xac, 0x6c, 0xec, 0x1c, 0x9c, 0x5c, 0xdc, 0x3c, 0xbc, 0x7c, 0xfc, + 0x02, 0x82, 0x42, 0xc2, 0x22, 0xa2, 0x62, 0xe2, 0x12, 0x92, 0x52, 0xd2, 0x32, 0xb2, 0x72, 0xf2, + 0x0a, 0x8a, 0x4a, 0xca, 0x2a, 0xaa, 0x6a, 0xea, 0x1a, 0x9a, 0x5a, 0xda, 0x3a, 0xba, 0x7a, 0xfa, + 0x06, 0x86, 0x46, 0xc6, 0x26, 0xa6, 0x66, 0xe6, 0x16, 0x96, 0x56, 0xd6, 0x36, 0xb6, 0x76, 0xf6, + 0x0e, 0x8e, 0x4e, 0xce, 0x2e, 0xae, 0x6e, 0xee, 0x1e, 0x9e, 0x5e, 0xde, 0x3e, 0xbe, 0x7e, 0xfe, + 0x01, 0x81, 0x41, 0xc1, 0x21, 0xa1, 0x61, 0xe1, 0x11, 0x91, 0x51, 0xd1, 0x31, 0xb1, 0x71, 0xf1, + 0x09, 0x89, 0x49, 0xc9, 0x29, 0xa9, 0x69, 0xe9, 0x19, 0x99, 0x59, 0xd9, 0x39, 0xb9, 0x79, 0xf9, + 0x05, 0x85, 0x45, 0xc5, 0x25, 0xa5, 0x65, 0xe5, 0x15, 0x95, 0x55, 0xd5, 0x35, 0xb5, 0x75, 0xf5, + 0x0d, 0x8d, 0x4d, 0xcd, 0x2d, 0xad, 0x6d, 0xed, 0x1d, 0x9d, 0x5d, 0xdd, 0x3d, 0xbd, 0x7d, 0xfd, + 0x03, 0x83, 0x43, 0xc3, 0x23, 0xa3, 0x63, 0xe3, 0x13, 0x93, 0x53, 0xd3, 0x33, 0xb3, 0x73, 0xf3, + 0x0b, 0x8b, 0x4b, 0xcb, 0x2b, 0xab, 0x6b, 0xeb, 0x1b, 0x9b, 0x5b, 0xdb, 0x3b, 0xbb, 0x7b, 0xfb, + 0x07, 0x87, 0x47, 0xc7, 0x27, 0xa7, 0x67, 0xe7, 0x17, 0x97, 0x57, 0xd7, 0x37, 0xb7, 0x77, 0xf7, + 0x0f, 0x8f, 0x4f, 0xcf, 0x2f, 0xaf, 0x6f, 0xef, 0x1f, 0x9f, 0x5f, 0xdf, 0x3f, 0xbf, 0x7f, 0xff, +} + +// hNode is a node in a Huffman tree. +type hNode struct { + // symbol is the symbol held by this node. + symbol uint32 + // children, if positive, is the hTree.nodes index of the first of + // this node's two children. Zero means an uninitialized node, + // and -1 means a leaf node. + children int32 +} + +const leafNode = -1 + +// lutSize is the log-2 size of an hTree's look-up table. +const lutSize, lutMask = 7, 1<<7 - 1 + +// hTree is a Huffman tree. +type hTree struct { + // nodes are the nodes of the Huffman tree. During construction, + // len(nodes) grows from 1 up to cap(nodes) by steps of two. + // After construction, len(nodes) == cap(nodes), and both equal + // 2*theNumberOfSymbols - 1. + nodes []hNode + // lut is a look-up table for walking the nodes. The x in lut[x] is + // the next lutSize bits in the bit-stream. The low 8 bits of lut[x] + // equals 1 plus the number of bits in the next code, or 0 if the + // next code requires more than lutSize bits. The high 24 bits are: + // - the symbol, if the code requires lutSize or fewer bits, or + // - the hTree.nodes index to start the tree traversal from, if + // the next code requires more than lutSize bits. + lut [1 << lutSize]uint32 +} + +// insert inserts into the hTree a symbol whose encoding is the least +// significant codeLength bits of code. +func (h *hTree) insert(symbol uint32, code uint32, codeLength uint32) error { + if symbol > 0xffff || codeLength > 0xfe { + return errInvalidHuffmanTree + } + baseCode := uint32(0) + if codeLength > lutSize { + baseCode = uint32(reverseBits[(code>>(codeLength-lutSize))&0xff]) >> (8 - lutSize) + } else { + baseCode = uint32(reverseBits[code&0xff]) >> (8 - codeLength) + for i := 0; i < 1<<(lutSize-codeLength); i++ { + h.lut[baseCode|uint32(i)< 0; { + codeLength-- + if int(n) > len(h.nodes) { + return errInvalidHuffmanTree + } + switch h.nodes[n].children { + case leafNode: + return errInvalidHuffmanTree + case 0: + if len(h.nodes) == cap(h.nodes) { + return errInvalidHuffmanTree + } + // Create two empty child nodes. + h.nodes[n].children = int32(len(h.nodes)) + h.nodes = h.nodes[:len(h.nodes)+2] + } + n = uint32(h.nodes[n].children) + 1&(code>>codeLength) + jump-- + if jump == 0 && h.lut[baseCode] == 0 { + h.lut[baseCode] = n << 8 + } + } + + switch h.nodes[n].children { + case leafNode: + // No-op. + case 0: + // Turn the uninitialized node into a leaf. + h.nodes[n].children = leafNode + default: + return errInvalidHuffmanTree + } + h.nodes[n].symbol = symbol + return nil +} + +// codeLengthsToCodes returns the canonical Huffman codes implied by the +// sequence of code lengths. +func codeLengthsToCodes(codeLengths []uint32) ([]uint32, error) { + maxCodeLength := uint32(0) + for _, cl := range codeLengths { + if maxCodeLength < cl { + maxCodeLength = cl + } + } + const maxAllowedCodeLength = 15 + if len(codeLengths) == 0 || maxCodeLength > maxAllowedCodeLength { + return nil, errInvalidHuffmanTree + } + histogram := [maxAllowedCodeLength + 1]uint32{} + for _, cl := range codeLengths { + histogram[cl]++ + } + currCode, nextCodes := uint32(0), [maxAllowedCodeLength + 1]uint32{} + for cl := 1; cl < len(nextCodes); cl++ { + currCode = (currCode + histogram[cl-1]) << 1 + nextCodes[cl] = currCode + } + codes := make([]uint32, len(codeLengths)) + for symbol, cl := range codeLengths { + if cl > 0 { + codes[symbol] = nextCodes[cl] + nextCodes[cl]++ + } + } + return codes, nil +} + +// build builds a canonical Huffman tree from the given code lengths. +func (h *hTree) build(codeLengths []uint32) error { + // Calculate the number of symbols. + var nSymbols, lastSymbol uint32 + for symbol, cl := range codeLengths { + if cl != 0 { + nSymbols++ + lastSymbol = uint32(symbol) + } + } + if nSymbols == 0 { + return errInvalidHuffmanTree + } + h.nodes = make([]hNode, 1, 2*nSymbols-1) + // Handle the trivial case. + if nSymbols == 1 { + if len(codeLengths) <= int(lastSymbol) { + return errInvalidHuffmanTree + } + return h.insert(lastSymbol, 0, 0) + } + // Handle the non-trivial case. + codes, err := codeLengthsToCodes(codeLengths) + if err != nil { + return err + } + for symbol, cl := range codeLengths { + if cl > 0 { + if err := h.insert(uint32(symbol), codes[symbol], cl); err != nil { + return err + } + } + } + return nil +} + +// buildSimple builds a Huffman tree with 1 or 2 symbols. +func (h *hTree) buildSimple(nSymbols uint32, symbols [2]uint32, alphabetSize uint32) error { + h.nodes = make([]hNode, 1, 2*nSymbols-1) + for i := uint32(0); i < nSymbols; i++ { + if symbols[i] >= alphabetSize { + return errInvalidHuffmanTree + } + if err := h.insert(symbols[i], i, nSymbols-1); err != nil { + return err + } + } + return nil +} + +// next returns the next Huffman-encoded symbol from the bit-stream d. +func (h *hTree) next(d *decoder) (uint32, error) { + var n uint32 + // Read enough bits so that we can use the look-up table. + if d.nBits < lutSize { + c, err := d.r.ReadByte() + if err != nil { + if err == io.EOF { + // There are no more bytes of data, but we may still be able + // to read the next symbol out of the previously read bits. + goto slowPath + } + return 0, err + } + d.bits |= uint32(c) << d.nBits + d.nBits += 8 + } + // Use the look-up table. + n = h.lut[d.bits&lutMask] + if b := n & 0xff; b != 0 { + b-- + d.bits >>= b + d.nBits -= b + return n >> 8, nil + } + n >>= 8 + d.bits >>= lutSize + d.nBits -= lutSize + +slowPath: + for h.nodes[n].children != leafNode { + if d.nBits == 0 { + c, err := d.r.ReadByte() + if err != nil { + if err == io.EOF { + err = io.ErrUnexpectedEOF + } + return 0, err + } + d.bits = uint32(c) + d.nBits = 8 + } + n = uint32(h.nodes[n].children) + 1&d.bits + d.bits >>= 1 + d.nBits-- + } + return h.nodes[n].symbol, nil +} diff --git a/vendor/golang.org/x/image/vp8l/transform.go b/vendor/golang.org/x/image/vp8l/transform.go new file mode 100644 index 0000000..06543da --- /dev/null +++ b/vendor/golang.org/x/image/vp8l/transform.go @@ -0,0 +1,299 @@ +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package vp8l + +// This file deals with image transforms, specified in section 3. + +// nTiles returns the number of tiles needed to cover size pixels, where each +// tile's side is 1<> bits +} + +const ( + transformTypePredictor = 0 + transformTypeCrossColor = 1 + transformTypeSubtractGreen = 2 + transformTypeColorIndexing = 3 + nTransformTypes = 4 +) + +// transform holds the parameters for an invertible transform. +type transform struct { + // transformType is the type of the transform. + transformType uint32 + // oldWidth is the width of the image before transformation (or + // equivalently, after inverse transformation). The color-indexing + // transform can reduce the width. For example, a 50-pixel-wide + // image that only needs 4 bits (half a byte) per color index can + // be transformed into a 25-pixel-wide image. + oldWidth int32 + // bits is the log-2 size of the transform's tiles, for the predictor + // and cross-color transforms. 8>>bits is the number of bits per + // color index, for the color-index transform. + bits uint32 + // pix is the tile values, for the predictor and cross-color + // transforms, and the color palette, for the color-index transform. + pix []byte +} + +var inverseTransforms = [nTransformTypes]func(*transform, []byte, int32) []byte{ + transformTypePredictor: inversePredictor, + transformTypeCrossColor: inverseCrossColor, + transformTypeSubtractGreen: inverseSubtractGreen, + transformTypeColorIndexing: inverseColorIndexing, +} + +func inversePredictor(t *transform, pix []byte, h int32) []byte { + if t.oldWidth == 0 || h == 0 { + return pix + } + // The first pixel's predictor is mode 0 (opaque black). + pix[3] += 0xff + p, mask := int32(4), int32(1)<> t.bits) * tilesPerRow + predictorMode := t.pix[q+1] & 0x0f + q += 4 + for x := int32(1); x < t.oldWidth; x++ { + if x&mask == 0 { + predictorMode = t.pix[q+1] & 0x0f + q += 4 + } + switch predictorMode { + case 0: // Opaque black. + pix[p+3] += 0xff + + case 1: // L. + pix[p+0] += pix[p-4] + pix[p+1] += pix[p-3] + pix[p+2] += pix[p-2] + pix[p+3] += pix[p-1] + + case 2: // T. + pix[p+0] += pix[top+0] + pix[p+1] += pix[top+1] + pix[p+2] += pix[top+2] + pix[p+3] += pix[top+3] + + case 3: // TR. + pix[p+0] += pix[top+4] + pix[p+1] += pix[top+5] + pix[p+2] += pix[top+6] + pix[p+3] += pix[top+7] + + case 4: // TL. + pix[p+0] += pix[top-4] + pix[p+1] += pix[top-3] + pix[p+2] += pix[top-2] + pix[p+3] += pix[top-1] + + case 5: // Average2(Average2(L, TR), T). + pix[p+0] += avg2(avg2(pix[p-4], pix[top+4]), pix[top+0]) + pix[p+1] += avg2(avg2(pix[p-3], pix[top+5]), pix[top+1]) + pix[p+2] += avg2(avg2(pix[p-2], pix[top+6]), pix[top+2]) + pix[p+3] += avg2(avg2(pix[p-1], pix[top+7]), pix[top+3]) + + case 6: // Average2(L, TL). + pix[p+0] += avg2(pix[p-4], pix[top-4]) + pix[p+1] += avg2(pix[p-3], pix[top-3]) + pix[p+2] += avg2(pix[p-2], pix[top-2]) + pix[p+3] += avg2(pix[p-1], pix[top-1]) + + case 7: // Average2(L, T). + pix[p+0] += avg2(pix[p-4], pix[top+0]) + pix[p+1] += avg2(pix[p-3], pix[top+1]) + pix[p+2] += avg2(pix[p-2], pix[top+2]) + pix[p+3] += avg2(pix[p-1], pix[top+3]) + + case 8: // Average2(TL, T). + pix[p+0] += avg2(pix[top-4], pix[top+0]) + pix[p+1] += avg2(pix[top-3], pix[top+1]) + pix[p+2] += avg2(pix[top-2], pix[top+2]) + pix[p+3] += avg2(pix[top-1], pix[top+3]) + + case 9: // Average2(T, TR). + pix[p+0] += avg2(pix[top+0], pix[top+4]) + pix[p+1] += avg2(pix[top+1], pix[top+5]) + pix[p+2] += avg2(pix[top+2], pix[top+6]) + pix[p+3] += avg2(pix[top+3], pix[top+7]) + + case 10: // Average2(Average2(L, TL), Average2(T, TR)). + pix[p+0] += avg2(avg2(pix[p-4], pix[top-4]), avg2(pix[top+0], pix[top+4])) + pix[p+1] += avg2(avg2(pix[p-3], pix[top-3]), avg2(pix[top+1], pix[top+5])) + pix[p+2] += avg2(avg2(pix[p-2], pix[top-2]), avg2(pix[top+2], pix[top+6])) + pix[p+3] += avg2(avg2(pix[p-1], pix[top-1]), avg2(pix[top+3], pix[top+7])) + + case 11: // Select(L, T, TL). + l0 := int32(pix[p-4]) + l1 := int32(pix[p-3]) + l2 := int32(pix[p-2]) + l3 := int32(pix[p-1]) + c0 := int32(pix[top-4]) + c1 := int32(pix[top-3]) + c2 := int32(pix[top-2]) + c3 := int32(pix[top-1]) + t0 := int32(pix[top+0]) + t1 := int32(pix[top+1]) + t2 := int32(pix[top+2]) + t3 := int32(pix[top+3]) + l := abs(c0-t0) + abs(c1-t1) + abs(c2-t2) + abs(c3-t3) + t := abs(c0-l0) + abs(c1-l1) + abs(c2-l2) + abs(c3-l3) + if l < t { + pix[p+0] += uint8(l0) + pix[p+1] += uint8(l1) + pix[p+2] += uint8(l2) + pix[p+3] += uint8(l3) + } else { + pix[p+0] += uint8(t0) + pix[p+1] += uint8(t1) + pix[p+2] += uint8(t2) + pix[p+3] += uint8(t3) + } + + case 12: // ClampAddSubtractFull(L, T, TL). + pix[p+0] += clampAddSubtractFull(pix[p-4], pix[top+0], pix[top-4]) + pix[p+1] += clampAddSubtractFull(pix[p-3], pix[top+1], pix[top-3]) + pix[p+2] += clampAddSubtractFull(pix[p-2], pix[top+2], pix[top-2]) + pix[p+3] += clampAddSubtractFull(pix[p-1], pix[top+3], pix[top-1]) + + case 13: // ClampAddSubtractHalf(Average2(L, T), TL). + pix[p+0] += clampAddSubtractHalf(avg2(pix[p-4], pix[top+0]), pix[top-4]) + pix[p+1] += clampAddSubtractHalf(avg2(pix[p-3], pix[top+1]), pix[top-3]) + pix[p+2] += clampAddSubtractHalf(avg2(pix[p-2], pix[top+2]), pix[top-2]) + pix[p+3] += clampAddSubtractHalf(avg2(pix[p-1], pix[top+3]), pix[top-1]) + } + p, top = p+4, top+4 + } + } + return pix +} + +func inverseCrossColor(t *transform, pix []byte, h int32) []byte { + var greenToRed, greenToBlue, redToBlue int32 + p, mask, tilesPerRow := int32(0), int32(1)<> t.bits) * tilesPerRow + for x := int32(0); x < t.oldWidth; x++ { + if x&mask == 0 { + redToBlue = int32(int8(t.pix[q+0])) + greenToBlue = int32(int8(t.pix[q+1])) + greenToRed = int32(int8(t.pix[q+2])) + q += 4 + } + red := pix[p+0] + green := pix[p+1] + blue := pix[p+2] + red += uint8(uint32(greenToRed*int32(int8(green))) >> 5) + blue += uint8(uint32(greenToBlue*int32(int8(green))) >> 5) + blue += uint8(uint32(redToBlue*int32(int8(red))) >> 5) + pix[p+0] = red + pix[p+2] = blue + p += 4 + } + } + return pix +} + +func inverseSubtractGreen(t *transform, pix []byte, h int32) []byte { + for p := 0; p < len(pix); p += 4 { + green := pix[p+1] + pix[p+0] += green + pix[p+2] += green + } + return pix +} + +func inverseColorIndexing(t *transform, pix []byte, h int32) []byte { + if t.bits == 0 { + for p := 0; p < len(pix); p += 4 { + i := 4 * uint32(pix[p+1]) + pix[p+0] = t.pix[i+0] + pix[p+1] = t.pix[i+1] + pix[p+2] = t.pix[i+2] + pix[p+3] = t.pix[i+3] + } + return pix + } + + vMask, xMask, bitsPerPixel := uint32(0), int32(0), uint32(8>>t.bits) + switch t.bits { + case 1: + vMask, xMask = 0x0f, 0x01 + case 2: + vMask, xMask = 0x03, 0x03 + case 3: + vMask, xMask = 0x01, 0x07 + } + + d, p, v, dst := 0, 0, uint32(0), make([]byte, 4*t.oldWidth*h) + for y := int32(0); y < h; y++ { + for x := int32(0); x < t.oldWidth; x++ { + if x&xMask == 0 { + v = uint32(pix[p+1]) + p += 4 + } + + i := 4 * (v & vMask) + dst[d+0] = t.pix[i+0] + dst[d+1] = t.pix[i+1] + dst[d+2] = t.pix[i+2] + dst[d+3] = t.pix[i+3] + d += 4 + + v >>= bitsPerPixel + } + } + return dst +} + +func abs(x int32) int32 { + if x < 0 { + return -x + } + return x +} + +func avg2(a, b uint8) uint8 { + return uint8((int32(a) + int32(b)) / 2) +} + +func clampAddSubtractFull(a, b, c uint8) uint8 { + x := int32(a) + int32(b) - int32(c) + if x < 0 { + return 0 + } + if x > 255 { + return 255 + } + return uint8(x) +} + +func clampAddSubtractHalf(a, b uint8) uint8 { + x := int32(a) + (int32(a)-int32(b))/2 + if x < 0 { + return 0 + } + if x > 255 { + return 255 + } + return uint8(x) +} diff --git a/vendor/modules.txt b/vendor/modules.txt index e1aa537..4a1898e 100644 --- a/vendor/modules.txt +++ b/vendor/modules.txt @@ -16,10 +16,7 @@ github.com/spf13/pflag # golang.org/x/image v0.1.0 ## explicit; go 1.12 golang.org/x/image/bmp -golang.org/x/image/ccitt golang.org/x/image/riff -golang.org/x/image/tiff -golang.org/x/image/tiff/lzw golang.org/x/image/vp8 golang.org/x/image/vp8l golang.org/x/image/webp