go.image/vp8: implement the loop filter.
The testdata files were created by: cwebp video-001.png -o video-001.webp dwebp -pgm video-001.webp -o tmp.pgm convert tmp.pgm video-001.webp.ycbcr.png rm tmp.pgm LGTM=r R=r CC=chaishushan, golang-codereviews https://golang.org/cl/91700044
This commit is contained in:
Nigel Tao
parent
38c1f4ffe8
commit
72be9c51b1
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testdata/video-001.webp
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testdata/video-001.webp
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testdata/video-001.webp.ycbcr.png
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testdata/video-001.webp.ycbcr.png
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@ -4,8 +4,7 @@
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// Package vp8 implements a vp8 image and video decoder.
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//
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// The VP8 specification is at:
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// http://datatracker.ietf.org/doc/rfc6386/
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// The VP8 specification is RFC 6386.
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package vp8
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// This file implements the top-level decoding algorithm.
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@ -121,6 +120,9 @@ type Decoder struct {
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tokenProb [nPlane][nBand][nContext][nProb]uint8
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useSkipProb bool
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skipProb uint8
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// Loop filter parameters.
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filterParams [nSegment][2]filterParam
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perMBFilterParams []filterParam
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// The eight fields below relate to the current macroblock being decoded.
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//
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@ -133,7 +135,7 @@ type Decoder struct {
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// Bitmasks for which 4x4 regions of coeff contain non-zero coefficients.
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nzDCMask, nzACMask uint32
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// Predictor modes.
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usePredY16 bool
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usePredY16 bool // The libwebp C code calls this !is_i4x4_.
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predY16 uint8
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predC8 uint8
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predY4 [4][4]uint8
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@ -202,6 +204,7 @@ func (d *Decoder) ensureImg() {
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}
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m := image.NewYCbCr(image.Rect(0, 0, 16*d.mbw, 16*d.mbh), image.YCbCrSubsampleRatio420)
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d.img = m.SubImage(image.Rect(0, 0, d.frameHeader.Width, d.frameHeader.Height)).(*image.YCbCr)
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d.perMBFilterParams = make([]filterParam, d.mbw*d.mbh)
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d.upMB = make([]mb, d.mbw)
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}
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@ -262,6 +265,7 @@ func (d *Decoder) parseFilterHeader() {
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} else {
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d.filterHeader.perSegmentLevel[0] = d.filterHeader.level
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}
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d.computeFilterParams()
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}
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// parseOtherPartitions parses the other partitions, as specified in section 9.5.
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@ -334,15 +338,18 @@ func (d *Decoder) DecodeFrame() (*image.YCbCr, error) {
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if err := d.parseOtherHeaders(); err != nil {
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return nil, err
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}
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// Reconstruct the rows.
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for mbx := 0; mbx < d.mbw; mbx++ {
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d.upMB[mbx] = mb{}
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}
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for mby := 0; mby < d.mbh; mby++ {
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d.leftMB = mb{}
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for mbx := 0; mbx < d.mbw; mbx++ {
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d.reconstruct(mbx, mby)
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skip := d.reconstruct(mbx, mby)
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fs := d.filterParams[d.segment][btou(!d.usePredY16)]
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fs.inner = fs.inner || !skip
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d.perMBFilterParams[d.mbw*mby+mbx] = fs
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}
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// TODO(nigeltao): filter, as specified in chapter 15.
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}
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if d.fp.unexpectedEOF {
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return nil, io.ErrUnexpectedEOF
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@ -352,5 +359,17 @@ func (d *Decoder) DecodeFrame() (*image.YCbCr, error) {
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return nil, io.ErrUnexpectedEOF
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}
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}
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// Apply the loop filter.
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//
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// Even if we are using per-segment levels, section 15 says that "loop
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// filtering must be skipped entirely if loop_filter_level at either the
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// frame header level or macroblock override level is 0".
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if d.filterHeader.level != 0 {
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if d.filterHeader.simple {
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d.simpleFilter()
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} else {
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// TODO(nigeltao): normal filtering.
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}
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}
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return d.img, nil
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}
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368
vp8/filter.go
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368
vp8/filter.go
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@ -0,0 +1,368 @@
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// Copyright 2014 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package vp8
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// filter2 modifies a 2-pixel-wide or 2-pixel-high band along an edge.
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func filter2(pix []byte, thresh int, index int, iStep int, jStep int) {
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for i := 0; i < 16; i, index = i+1, index+iStep {
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p1 := int(pix[index-2*jStep])
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p0 := int(pix[index-1*jStep])
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q0 := int(pix[index+0*jStep])
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q1 := int(pix[index+1*jStep])
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if int(lutAbs[lutAbsBase+p0-q0])<<1+int(lutAbs[lutAbsBase+p1-q1])>>1 > thresh {
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continue
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}
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a := 3*(q0-p0) + int(lutClamp127[lutClamp127Base+p1-q1])
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a1 := int(lutClamp15[lutClamp15Base+((a+4)>>3)])
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a2 := int(lutClamp15[lutClamp15Base+((a+3)>>3)])
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pix[index-1*jStep] = lutClamp255[lutClamp255Base+p0+a2]
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pix[index+0*jStep] = lutClamp255[lutClamp255Base+q0-a1]
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}
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}
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// TODO(nigeltao): filter4 and filter6 functions, for normal filtering.
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// simpleFilter implements the simple filter, as specified in section 15.2.
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func (d *Decoder) simpleFilter() {
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for mby := 0; mby < d.mbh; mby++ {
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for mbx := 0; mbx < d.mbw; mbx++ {
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f := d.perMBFilterParams[d.mbw*mby+mbx]
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if f.limit == 0 {
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continue
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}
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index := (mby*d.img.YStride + mbx) * 16
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if mbx > 0 {
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filter2(d.img.Y, int(f.limit)+4, index, d.img.YStride, 1)
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}
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if f.inner {
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filter2(d.img.Y, int(f.limit), index+4, d.img.YStride, 1)
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filter2(d.img.Y, int(f.limit), index+8, d.img.YStride, 1)
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filter2(d.img.Y, int(f.limit), index+12, d.img.YStride, 1)
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}
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if mby > 0 {
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filter2(d.img.Y, int(f.limit)+4, index, 1, d.img.YStride)
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}
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if f.inner {
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filter2(d.img.Y, int(f.limit), index+d.img.YStride*4, 1, d.img.YStride)
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filter2(d.img.Y, int(f.limit), index+d.img.YStride*8, 1, d.img.YStride)
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filter2(d.img.Y, int(f.limit), index+d.img.YStride*12, 1, d.img.YStride)
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}
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}
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}
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}
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// filterParam holds the loop filter parameters for a macroblock.
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type filterParam struct {
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limit uint8
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inner bool
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innerLevel uint8
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hevThresh uint8
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}
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// computeFilterParams computes the loop filter parameters, as specified in
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// section 15.4.
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func (d *Decoder) computeFilterParams() {
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for i := range d.filterParams {
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baseLevel := d.filterHeader.level
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if d.segmentHeader.useSegment {
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baseLevel = d.segmentHeader.filterStrength[i]
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if d.segmentHeader.relativeDelta {
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baseLevel += d.filterHeader.level
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}
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}
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for j := range d.filterParams[i] {
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p := &d.filterParams[i][j]
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p.inner = j != 0
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level := baseLevel
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if d.filterHeader.useLFDelta {
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// The libwebp C code has a "TODO: only CURRENT is handled for now."
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level += d.filterHeader.refLFDelta[0]
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if j != 0 {
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level += d.filterHeader.modeLFDelta[0]
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}
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}
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if level <= 0 {
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p.limit = 0
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continue
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}
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if level > 63 {
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level = 63
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}
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ilevel := level
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if d.filterHeader.sharpness > 0 {
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if d.filterHeader.sharpness > 4 {
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ilevel >>= 2
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} else {
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ilevel >>= 1
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}
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if x := int8(9 - d.filterHeader.sharpness); ilevel > x {
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ilevel = x
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}
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}
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if ilevel < 1 {
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ilevel = 1
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}
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p.innerLevel = uint8(ilevel)
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p.limit = uint8(2*level + ilevel)
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if d.frameHeader.KeyFrame {
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if level < 15 {
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p.hevThresh = 0
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} else if level < 40 {
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p.hevThresh = 1
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} else {
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p.hevThresh = 2
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}
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} else {
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if level < 15 {
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p.hevThresh = 0
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} else if level < 20 {
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p.hevThresh = 1
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} else if level < 40 {
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p.hevThresh = 2
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} else {
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p.hevThresh = 3
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}
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}
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}
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}
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}
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// Look-up tables.
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//
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// TODO(nigeltao): are these actually worth it in Go, as opposed to C,
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// due to the bounds checking?
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const lutAbsBase = 255
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// lutAbs[lutAbsBase+x] is equal to abs(x), for x in [-255, 255].
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var lutAbs = [255 + 1 + 255]uint8{
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0xff, 0xfe, 0xfd, 0xfc, 0xfb, 0xfa, 0xf9, 0xf8, 0xf7, 0xf6, 0xf5, 0xf4, 0xf3, 0xf2, 0xf1, 0xf0,
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0xef, 0xee, 0xed, 0xec, 0xeb, 0xea, 0xe9, 0xe8, 0xe7, 0xe6, 0xe5, 0xe4, 0xe3, 0xe2, 0xe1, 0xe0,
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0xdf, 0xde, 0xdd, 0xdc, 0xdb, 0xda, 0xd9, 0xd8, 0xd7, 0xd6, 0xd5, 0xd4, 0xd3, 0xd2, 0xd1, 0xd0,
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0xcf, 0xce, 0xcd, 0xcc, 0xcb, 0xca, 0xc9, 0xc8, 0xc7, 0xc6, 0xc5, 0xc4, 0xc3, 0xc2, 0xc1, 0xc0,
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0xbf, 0xbe, 0xbd, 0xbc, 0xbb, 0xba, 0xb9, 0xb8, 0xb7, 0xb6, 0xb5, 0xb4, 0xb3, 0xb2, 0xb1, 0xb0,
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0xaf, 0xae, 0xad, 0xac, 0xab, 0xaa, 0xa9, 0xa8, 0xa7, 0xa6, 0xa5, 0xa4, 0xa3, 0xa2, 0xa1, 0xa0,
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0x9f, 0x9e, 0x9d, 0x9c, 0x9b, 0x9a, 0x99, 0x98, 0x97, 0x96, 0x95, 0x94, 0x93, 0x92, 0x91, 0x90,
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0x8f, 0x8e, 0x8d, 0x8c, 0x8b, 0x8a, 0x89, 0x88, 0x87, 0x86, 0x85, 0x84, 0x83, 0x82, 0x81, 0x80,
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0x7f, 0x7e, 0x7d, 0x7c, 0x7b, 0x7a, 0x79, 0x78, 0x77, 0x76, 0x75, 0x74, 0x73, 0x72, 0x71, 0x70,
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0x6f, 0x6e, 0x6d, 0x6c, 0x6b, 0x6a, 0x69, 0x68, 0x67, 0x66, 0x65, 0x64, 0x63, 0x62, 0x61, 0x60,
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0x5f, 0x5e, 0x5d, 0x5c, 0x5b, 0x5a, 0x59, 0x58, 0x57, 0x56, 0x55, 0x54, 0x53, 0x52, 0x51, 0x50,
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0x4f, 0x4e, 0x4d, 0x4c, 0x4b, 0x4a, 0x49, 0x48, 0x47, 0x46, 0x45, 0x44, 0x43, 0x42, 0x41, 0x40,
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0x3f, 0x3e, 0x3d, 0x3c, 0x3b, 0x3a, 0x39, 0x38, 0x37, 0x36, 0x35, 0x34, 0x33, 0x32, 0x31, 0x30,
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0x2f, 0x2e, 0x2d, 0x2c, 0x2b, 0x2a, 0x29, 0x28, 0x27, 0x26, 0x25, 0x24, 0x23, 0x22, 0x21, 0x20,
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0x1f, 0x1e, 0x1d, 0x1c, 0x1b, 0x1a, 0x19, 0x18, 0x17, 0x16, 0x15, 0x14, 0x13, 0x12, 0x11, 0x10,
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0x0f, 0x0e, 0x0d, 0x0c, 0x0b, 0x0a, 0x09, 0x08, 0x07, 0x06, 0x05, 0x04, 0x03, 0x02, 0x01, 0x00,
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0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10,
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0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20,
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0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, 0x30,
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0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, 0x40,
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0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, 0x50,
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0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, 0x60,
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0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70,
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0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, 0x80,
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0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, 0x90,
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0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, 0xa0,
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0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf, 0xb0,
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0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf, 0xc0,
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0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf, 0xd0,
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0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf, 0xe0,
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0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef, 0xf0,
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0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff,
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}
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const lutClamp15Base = 255
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// lutClamp15[lutClamp15Base+x] is equal to clamp(x, -16, +15), for x in [-255, 255].
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var lutClamp15 = [255 + 1 + 255]int8{
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-0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10,
|
||||
-0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10,
|
||||
-0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10,
|
||||
-0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10,
|
||||
-0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10,
|
||||
-0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10,
|
||||
-0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10,
|
||||
-0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10,
|
||||
-0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10,
|
||||
-0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10,
|
||||
-0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10,
|
||||
-0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10,
|
||||
-0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10,
|
||||
-0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10,
|
||||
-0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10,
|
||||
-0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10,
|
||||
-0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10,
|
||||
-0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10,
|
||||
-0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10,
|
||||
-0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10,
|
||||
-0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10,
|
||||
-0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10,
|
||||
-0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10,
|
||||
-0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10,
|
||||
-0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10,
|
||||
-0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10,
|
||||
-0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10,
|
||||
-0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10,
|
||||
-0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10,
|
||||
-0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10, -0x10,
|
||||
-0x0f, -0x0e, -0x0d, -0x0c, -0x0b, -0x0a, -0x09, -0x08,
|
||||
-0x07, -0x06, -0x05, -0x04, -0x03, -0x02, -0x01, +0x00,
|
||||
+0x01, +0x02, +0x03, +0x04, +0x05, +0x06, +0x07, +0x08,
|
||||
+0x09, +0x0a, +0x0b, +0x0c, +0x0d, +0x0e, +0x0f, +0x0f,
|
||||
+0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f,
|
||||
+0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f,
|
||||
+0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f,
|
||||
+0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f,
|
||||
+0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f,
|
||||
+0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f,
|
||||
+0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f,
|
||||
+0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f,
|
||||
+0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f,
|
||||
+0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f,
|
||||
+0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f,
|
||||
+0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f,
|
||||
+0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f,
|
||||
+0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f,
|
||||
+0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f,
|
||||
+0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f,
|
||||
+0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f,
|
||||
+0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f,
|
||||
+0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f,
|
||||
+0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f,
|
||||
+0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f,
|
||||
+0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f,
|
||||
+0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f,
|
||||
+0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f,
|
||||
+0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f,
|
||||
+0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f,
|
||||
+0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f,
|
||||
+0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f,
|
||||
+0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f,
|
||||
+0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f,
|
||||
}
|
||||
|
||||
const lutClamp127Base = 255
|
||||
|
||||
// lutClamp127[lutClamp127Base+x] is equal to clamp(x, -128, +127), for x in [-255, 255].
|
||||
var lutClamp127 = [255 + 1 + 255]int8{
|
||||
-0x80, -0x80, -0x80, -0x80, -0x80, -0x80, -0x80, -0x80,
|
||||
-0x80, -0x80, -0x80, -0x80, -0x80, -0x80, -0x80, -0x80,
|
||||
-0x80, -0x80, -0x80, -0x80, -0x80, -0x80, -0x80, -0x80,
|
||||
-0x80, -0x80, -0x80, -0x80, -0x80, -0x80, -0x80, -0x80,
|
||||
-0x80, -0x80, -0x80, -0x80, -0x80, -0x80, -0x80, -0x80,
|
||||
-0x80, -0x80, -0x80, -0x80, -0x80, -0x80, -0x80, -0x80,
|
||||
-0x80, -0x80, -0x80, -0x80, -0x80, -0x80, -0x80, -0x80,
|
||||
-0x80, -0x80, -0x80, -0x80, -0x80, -0x80, -0x80, -0x80,
|
||||
-0x80, -0x80, -0x80, -0x80, -0x80, -0x80, -0x80, -0x80,
|
||||
-0x80, -0x80, -0x80, -0x80, -0x80, -0x80, -0x80, -0x80,
|
||||
-0x80, -0x80, -0x80, -0x80, -0x80, -0x80, -0x80, -0x80,
|
||||
-0x80, -0x80, -0x80, -0x80, -0x80, -0x80, -0x80, -0x80,
|
||||
-0x80, -0x80, -0x80, -0x80, -0x80, -0x80, -0x80, -0x80,
|
||||
-0x80, -0x80, -0x80, -0x80, -0x80, -0x80, -0x80, -0x80,
|
||||
-0x80, -0x80, -0x80, -0x80, -0x80, -0x80, -0x80, -0x80,
|
||||
-0x80, -0x80, -0x80, -0x80, -0x80, -0x80, -0x80, -0x80,
|
||||
-0x7f, -0x7e, -0x7d, -0x7c, -0x7b, -0x7a, -0x79, -0x78,
|
||||
-0x77, -0x76, -0x75, -0x74, -0x73, -0x72, -0x71, -0x70,
|
||||
-0x6f, -0x6e, -0x6d, -0x6c, -0x6b, -0x6a, -0x69, -0x68,
|
||||
-0x67, -0x66, -0x65, -0x64, -0x63, -0x62, -0x61, -0x60,
|
||||
-0x5f, -0x5e, -0x5d, -0x5c, -0x5b, -0x5a, -0x59, -0x58,
|
||||
-0x57, -0x56, -0x55, -0x54, -0x53, -0x52, -0x51, -0x50,
|
||||
-0x4f, -0x4e, -0x4d, -0x4c, -0x4b, -0x4a, -0x49, -0x48,
|
||||
-0x47, -0x46, -0x45, -0x44, -0x43, -0x42, -0x41, -0x40,
|
||||
-0x3f, -0x3e, -0x3d, -0x3c, -0x3b, -0x3a, -0x39, -0x38,
|
||||
-0x37, -0x36, -0x35, -0x34, -0x33, -0x32, -0x31, -0x30,
|
||||
-0x2f, -0x2e, -0x2d, -0x2c, -0x2b, -0x2a, -0x29, -0x28,
|
||||
-0x27, -0x26, -0x25, -0x24, -0x23, -0x22, -0x21, -0x20,
|
||||
-0x1f, -0x1e, -0x1d, -0x1c, -0x1b, -0x1a, -0x19, -0x18,
|
||||
-0x17, -0x16, -0x15, -0x14, -0x13, -0x12, -0x11, -0x10,
|
||||
-0x0f, -0x0e, -0x0d, -0x0c, -0x0b, -0x0a, -0x09, -0x08,
|
||||
-0x07, -0x06, -0x05, -0x04, -0x03, -0x02, -0x01, +0x00,
|
||||
+0x01, +0x02, +0x03, +0x04, +0x05, +0x06, +0x07, +0x08,
|
||||
+0x09, +0x0a, +0x0b, +0x0c, +0x0d, +0x0e, +0x0f, +0x10,
|
||||
+0x11, +0x12, +0x13, +0x14, +0x15, +0x16, +0x17, +0x18,
|
||||
+0x19, +0x1a, +0x1b, +0x1c, +0x1d, +0x1e, +0x1f, +0x20,
|
||||
+0x21, +0x22, +0x23, +0x24, +0x25, +0x26, +0x27, +0x28,
|
||||
+0x29, +0x2a, +0x2b, +0x2c, +0x2d, +0x2e, +0x2f, +0x30,
|
||||
+0x31, +0x32, +0x33, +0x34, +0x35, +0x36, +0x37, +0x38,
|
||||
+0x39, +0x3a, +0x3b, +0x3c, +0x3d, +0x3e, +0x3f, +0x40,
|
||||
+0x41, +0x42, +0x43, +0x44, +0x45, +0x46, +0x47, +0x48,
|
||||
+0x49, +0x4a, +0x4b, +0x4c, +0x4d, +0x4e, +0x4f, +0x50,
|
||||
+0x51, +0x52, +0x53, +0x54, +0x55, +0x56, +0x57, +0x58,
|
||||
+0x59, +0x5a, +0x5b, +0x5c, +0x5d, +0x5e, +0x5f, +0x60,
|
||||
+0x61, +0x62, +0x63, +0x64, +0x65, +0x66, +0x67, +0x68,
|
||||
+0x69, +0x6a, +0x6b, +0x6c, +0x6d, +0x6e, +0x6f, +0x70,
|
||||
+0x71, +0x72, +0x73, +0x74, +0x75, +0x76, +0x77, +0x78,
|
||||
+0x79, +0x7a, +0x7b, +0x7c, +0x7d, +0x7e, +0x7f, +0x7f,
|
||||
+0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f,
|
||||
+0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f,
|
||||
+0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f,
|
||||
+0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f,
|
||||
+0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f,
|
||||
+0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f,
|
||||
+0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f,
|
||||
+0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f,
|
||||
+0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f,
|
||||
+0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f,
|
||||
+0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f,
|
||||
+0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f,
|
||||
+0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f,
|
||||
+0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f,
|
||||
+0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f,
|
||||
+0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f, +0x7f,
|
||||
}
|
||||
|
||||
const lutClamp255Base = 255
|
||||
|
||||
// lutClamp255[lutClamp255Base+x] is equal to clamp(x, 0, 255), for x in [-255, 510].
|
||||
var lutClamp255 = [255 + 1 + 510]uint8{
|
||||
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
|
||||
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
|
||||
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
|
||||
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
|
||||
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
|
||||
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
|
||||
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
|
||||
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
|
||||
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
|
||||
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
|
||||
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
|
||||
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
|
||||
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
|
||||
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
|
||||
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
|
||||
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
|
||||
0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10,
|
||||
0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20,
|
||||
0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, 0x30,
|
||||
0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, 0x40,
|
||||
0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, 0x50,
|
||||
0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, 0x60,
|
||||
0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70,
|
||||
0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, 0x80,
|
||||
0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, 0x90,
|
||||
0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, 0xa0,
|
||||
0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf, 0xb0,
|
||||
0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf, 0xc0,
|
||||
0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf, 0xd0,
|
||||
0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf, 0xe0,
|
||||
0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef, 0xf0,
|
||||
0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff, 0xff,
|
||||
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
|
||||
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
|
||||
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
|
||||
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
|
||||
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
|
||||
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
|
||||
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
|
||||
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
|
||||
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
|
||||
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
|
||||
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
|
||||
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
|
||||
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
|
||||
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
|
||||
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
|
||||
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
|
||||
}
|
||||
|
|
@ -385,7 +385,7 @@ func (d *Decoder) reconstructMacroblock(mbx, mby int) {
|
|||
}
|
||||
|
||||
// reconstruct reconstructs one macroblock.
|
||||
func (d *Decoder) reconstruct(mbx, mby int) {
|
||||
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))
|
||||
|
|
@ -393,7 +393,6 @@ func (d *Decoder) reconstruct(mbx, mby int) {
|
|||
d.segment = int(d.fp.readUint(d.segmentHeader.prob[2], 1)) + 2
|
||||
}
|
||||
}
|
||||
skip := false
|
||||
if d.useSkipProb {
|
||||
skip = d.fp.readBit(d.skipProb)
|
||||
}
|
||||
|
|
@ -412,6 +411,8 @@ func (d *Decoder) reconstruct(mbx, mby int) {
|
|||
d.parsePredModeC8()
|
||||
// Parse the residuals.
|
||||
if !skip {
|
||||
// TODO(nigeltao): make d.parseResiduals return a bool, and change this to
|
||||
// skip = d.parseResiduals(mbx, mby)
|
||||
d.parseResiduals(mbx, mby)
|
||||
} else {
|
||||
if d.usePredY16 {
|
||||
|
|
@ -432,4 +433,5 @@ func (d *Decoder) reconstruct(mbx, mby int) {
|
|||
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
|
||||
}
|
||||
|
|
|
|||
110
webp/decode_test.go
Normal file
110
webp/decode_test.go
Normal file
|
|
@ -0,0 +1,110 @@
|
|||
// 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 webp
|
||||
|
||||
import (
|
||||
"bytes"
|
||||
"fmt"
|
||||
"image"
|
||||
"image/png"
|
||||
"os"
|
||||
"testing"
|
||||
)
|
||||
|
||||
// hex is like fmt.Sprintf("% x", x) but also inserts dots every 16 bytes, to
|
||||
// delineate VP8 macroblock boundaries.
|
||||
func hex(x []byte) string {
|
||||
buf := new(bytes.Buffer)
|
||||
for len(x) > 0 {
|
||||
n := len(x)
|
||||
if n > 16 {
|
||||
n = 16
|
||||
}
|
||||
fmt.Fprintf(buf, " . % x", x[:n])
|
||||
x = x[n:]
|
||||
}
|
||||
return buf.String()
|
||||
}
|
||||
|
||||
func TestDecodeVP8(t *testing.T) {
|
||||
// The original video-001.png image is 150x103.
|
||||
const w, h = 150, 103
|
||||
// w2 and h2 are the half-width and half-height, rounded up.
|
||||
const w2, h2 = int((w + 1) / 2), int((h + 1) / 2)
|
||||
|
||||
f0, err := os.Open("../testdata/video-001.webp.ycbcr.png")
|
||||
if err != nil {
|
||||
t.Fatal(err)
|
||||
}
|
||||
defer f0.Close()
|
||||
img0, err := png.Decode(f0)
|
||||
if err != nil {
|
||||
t.Fatal(err)
|
||||
}
|
||||
|
||||
// The split-into-YCbCr-planes golden image is a 2*w2 wide and h+h2 high
|
||||
// gray image arranged in IMC4 format:
|
||||
// YYYY
|
||||
// YYYY
|
||||
// BBRR
|
||||
// See http://www.fourcc.org/yuv.php#IMC4
|
||||
if got, want := img0.Bounds(), image.Rect(0, 0, 2*w2, h+h2); got != want {
|
||||
t.Fatalf("bounds0: got %v, want %v", got, want)
|
||||
}
|
||||
m0, ok := img0.(*image.Gray)
|
||||
if !ok {
|
||||
t.Fatal("decoded PNG image is not a Gray")
|
||||
}
|
||||
|
||||
f1, err := os.Open("../testdata/video-001.webp")
|
||||
if err != nil {
|
||||
t.Fatal(err)
|
||||
}
|
||||
defer f1.Close()
|
||||
img1, err := Decode(f1)
|
||||
if err != nil {
|
||||
t.Fatal(err)
|
||||
}
|
||||
|
||||
if got, want := img1.Bounds(), image.Rect(0, 0, w, h); got != want {
|
||||
t.Fatalf("bounds1: got %v, want %v", got, want)
|
||||
}
|
||||
m1, ok := img1.(*image.YCbCr)
|
||||
if !ok || m1.SubsampleRatio != image.YCbCrSubsampleRatio420 {
|
||||
t.Fatal("decoded WEBP image is not a 4:2:0 YCbCr")
|
||||
}
|
||||
|
||||
planes := []struct {
|
||||
name string
|
||||
m1Pix []uint8
|
||||
m1Stride int
|
||||
m0Rect image.Rectangle
|
||||
}{
|
||||
{"Y", m1.Y, m1.YStride, image.Rect(0, 0, w, h)},
|
||||
{"Cb", m1.Cb, m1.CStride, image.Rect(0*w2, h, 1*w2, h+h2)},
|
||||
{"Cr", m1.Cr, m1.CStride, image.Rect(1*w2, h, 2*w2, h+h2)},
|
||||
}
|
||||
for _, plane := range planes {
|
||||
dx := plane.m0Rect.Dx()
|
||||
nDiff, diff := 0, make([]byte, dx)
|
||||
for j, y := 0, plane.m0Rect.Min.Y; y < plane.m0Rect.Max.Y; j, y = j+1, y+1 {
|
||||
got := plane.m1Pix[j*plane.m1Stride:][:dx]
|
||||
want := m0.Pix[y*m0.Stride+plane.m0Rect.Min.X:][:dx]
|
||||
if bytes.Equal(got, want) {
|
||||
continue
|
||||
}
|
||||
nDiff++
|
||||
if nDiff > 10 {
|
||||
t.Errorf("%s plane: more rows differ", plane.name)
|
||||
break
|
||||
}
|
||||
for i := range got {
|
||||
diff[i] = got[i] - want[i]
|
||||
}
|
||||
t.Errorf("%s plane: m0 row %d, m1 row %d\ngot %s\nwant%s\ndiff%s",
|
||||
plane.name, y, j, hex(got), hex(want), hex(diff))
|
||||
}
|
||||
}
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user