go.image/vp8: implement the normal filter.

The testdata was generated via:
cwebp foo.png -o foo.lossy.webp
dwebp -pgm foo.lossy.webp -o tmp.pgm
convert tmp.pgm foo.lossy.webp.ycbcr.png
rm tmp.pgm

TBR=r
R=r
CC=golang-codereviews
https://golang.org/cl/107330043
This commit is contained in:
Nigel Tao 2014-06-26 13:29:30 +10:00
parent 94ba43c478
commit 0424e74a0e
8 changed files with 432 additions and 138 deletions

BIN
testdata/blue-purple-pink.lossy.webp vendored Normal file

Binary file not shown.

After

Width:  |  Height:  |  Size: 2.4 KiB

Binary file not shown.

After

Width:  |  Height:  |  Size: 11 KiB

View File

Before

Width:  |  Height:  |  Size: 3.2 KiB

After

Width:  |  Height:  |  Size: 3.2 KiB

View File

Before

Width:  |  Height:  |  Size: 12 KiB

After

Width:  |  Height:  |  Size: 12 KiB

Binary file not shown.

After

Width:  |  Height:  |  Size: 60 KiB

View File

@ -368,7 +368,7 @@ func (d *Decoder) DecodeFrame() (*image.YCbCr, error) {
if d.filterHeader.simple {
d.simpleFilter()
} else {
// TODO(nigeltao): normal filtering.
d.normalFilter()
}
}
return d.img, nil

View File

@ -4,14 +4,14 @@
package vp8
// filter2 modifies a 2-pixel-wide or 2-pixel-high band along an edge.
func filter2(pix []byte, thresh int, index int, iStep int, jStep int) {
for i := 0; i < 16; i, index = i+1, index+iStep {
// 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 int(lutAbs[lutAbsBase+p0-q0])<<1+int(lutAbs[lutAbsBase+p1-q1])>>1 > thresh {
if int(lutAbs[lutAbsBase+p0-q0])<<1+int(lutAbs[lutAbsBase+p1-q1])>>1 > level {
continue
}
a := 3*(q0-p0) + int(lutClamp127[lutClamp127Base+p1-q1])
@ -22,32 +22,126 @@ func filter2(pix []byte, thresh int, index int, iStep int, jStep int) {
}
}
// TODO(nigeltao): filter4 and filter6 functions, for normal filtering.
// 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 int(lutAbs[lutAbsBase+p0-q0])<<1+int(lutAbs[lutAbsBase+p1-q1])>>1 > level {
continue
}
if int(lutAbs[lutAbsBase+p3-p2]) > ilevel ||
int(lutAbs[lutAbsBase+p2-p1]) > ilevel ||
int(lutAbs[lutAbsBase+p1-p0]) > ilevel ||
int(lutAbs[lutAbsBase+q1-q0]) > ilevel ||
int(lutAbs[lutAbsBase+q2-q1]) > ilevel ||
int(lutAbs[lutAbsBase+q3-q2]) > ilevel {
continue
}
if int(lutAbs[lutAbsBase+p1-p0]) > hlevel || int(lutAbs[lutAbsBase+q1-q0]) > hlevel {
// Filter 2 pixels.
a := 3*(q0-p0) + int(lutClamp127[lutClamp127Base+p1-q1])
a1 := int(lutClamp15[lutClamp15Base+((a+4)>>3)])
a2 := int(lutClamp15[lutClamp15Base+((a+3)>>3)])
pix[index-1*jStep] = lutClamp255[lutClamp255Base+p0+a2]
pix[index+0*jStep] = lutClamp255[lutClamp255Base+q0-a1]
} else if fourNotSix {
// Filter 4 pixels.
a := 3 * (q0 - p0)
a1 := int(lutClamp15[lutClamp15Base+((a+4)>>3)])
a2 := int(lutClamp15[lutClamp15Base+((a+3)>>3)])
a3 := (a1 + 1) >> 1
pix[index-2*jStep] = lutClamp255[lutClamp255Base+p1+a3]
pix[index-1*jStep] = lutClamp255[lutClamp255Base+p0+a2]
pix[index+0*jStep] = lutClamp255[lutClamp255Base+q0-a1]
pix[index+1*jStep] = lutClamp255[lutClamp255Base+q1-a3]
} else {
// Filter 6 pixels.
a := 3*(q0-p0) + int(lutClamp127[lutClamp127Base+p1-q1])
a = int(lutClamp127[lutClamp127Base+a])
a1 := (27*a + 63) >> 7
a2 := (18*a + 63) >> 7
a3 := (9*a + 63) >> 7
pix[index-3*jStep] = lutClamp255[lutClamp255Base+p2+a3]
pix[index-2*jStep] = lutClamp255[lutClamp255Base+p1+a2]
pix[index-1*jStep] = lutClamp255[lutClamp255Base+p0+a1]
pix[index+0*jStep] = lutClamp255[lutClamp255Base+q0-a1]
pix[index+1*jStep] = lutClamp255[lutClamp255Base+q1-a2]
pix[index+2*jStep] = lutClamp255[lutClamp255Base+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.limit == 0 {
if f.level == 0 {
continue
}
index := (mby*d.img.YStride + mbx) * 16
l := int(f.level)
yIndex := (mby*d.img.YStride + mbx) * 16
if mbx > 0 {
filter2(d.img.Y, int(f.limit)+4, index, d.img.YStride, 1)
filter2(d.img.Y, l+4, yIndex, d.img.YStride, 1)
}
if f.inner {
filter2(d.img.Y, int(f.limit), index+4, d.img.YStride, 1)
filter2(d.img.Y, int(f.limit), index+8, d.img.YStride, 1)
filter2(d.img.Y, int(f.limit), index+12, d.img.YStride, 1)
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, int(f.limit)+4, index, 1, d.img.YStride)
filter2(d.img.Y, l+4, yIndex, 1, d.img.YStride)
}
if f.inner {
filter2(d.img.Y, int(f.limit), index+d.img.YStride*4, 1, d.img.YStride)
filter2(d.img.Y, int(f.limit), index+d.img.YStride*8, 1, d.img.YStride)
filter2(d.img.Y, int(f.limit), index+d.img.YStride*12, 1, d.img.YStride)
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)
}
}
}
@ -55,10 +149,14 @@ func (d *Decoder) simpleFilter() {
// filterParam holds the loop filter parameters for a macroblock.
type filterParam struct {
limit uint8
inner bool
innerLevel uint8
hevThresh uint8
// 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
@ -85,7 +183,7 @@ func (d *Decoder) computeFilterParams() {
}
}
if level <= 0 {
p.limit = 0
p.level = 0
continue
}
if level > 63 {
@ -105,25 +203,25 @@ func (d *Decoder) computeFilterParams() {
if ilevel < 1 {
ilevel = 1
}
p.innerLevel = uint8(ilevel)
p.limit = uint8(2*level + ilevel)
p.ilevel = uint8(ilevel)
p.level = uint8(2*level + ilevel)
if d.frameHeader.KeyFrame {
if level < 15 {
p.hevThresh = 0
p.hlevel = 0
} else if level < 40 {
p.hevThresh = 1
p.hlevel = 1
} else {
p.hevThresh = 2
p.hlevel = 2
}
} else {
if level < 15 {
p.hevThresh = 0
p.hlevel = 0
} else if level < 20 {
p.hevThresh = 1
p.hlevel = 1
} else if level < 40 {
p.hevThresh = 2
p.hlevel = 2
} else {
p.hevThresh = 3
p.hlevel = 3
}
}
}
@ -243,10 +341,10 @@ var lutClamp15 = [255 + 1 + 255]int8{
+0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f, +0x0f,
}
const lutClamp127Base = 255
const lutClamp127Base = 1020
// lutClamp127[lutClamp127Base+x] is equal to clamp(x, -128, +127), for x in [-255, 255].
var lutClamp127 = [255 + 1 + 255]int8{
// lutClamp127[lutClamp127Base+x] is equal to clamp(x, -128, +127), for x in [-1020, 1020].
var lutClamp127 = [1020 + 1 + 1020]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,
@ -263,38 +361,134 @@ 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,
-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,
-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,
-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,
-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,
-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,
-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,
-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,
@ -310,7 +504,103 @@ var lutClamp127 = [255 + 1 + 255]int8{
+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, +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, +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, +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, +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, +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, +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

View File

@ -31,82 +31,85 @@ func hex(x []byte) 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)
testCases := []string{
"blue-purple-pink",
"video-001",
"yellow_rose",
}
// 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")
}
for _, tc := range testCases {
f0, err := os.Open("../testdata/" + tc + ".lossy.webp")
if err != nil {
t.Fatal(err)
}
defer f0.Close()
img0, err := Decode(f0)
if err != nil {
t.Fatal(err)
}
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)
}
m0, ok := img0.(*image.YCbCr)
if !ok || m0.SubsampleRatio != image.YCbCrSubsampleRatio420 {
t.Fatal("decoded WEBP image is not a 4:2:0 YCbCr")
}
// w2 and h2 are the half-width and half-height, rounded up.
w, h := m0.Bounds().Dx(), m0.Bounds().Dy()
w2, h2 := int((w+1)/2), int((h+1)/2)
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")
}
f1, err := os.Open("../testdata/" + tc + ".lossy.webp.ycbcr.png")
if err != nil {
t.Fatal(err)
}
defer f1.Close()
img1, err := png.Decode(f1)
if err != nil {
t.Fatal(err)
}
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
// 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 := img1.Bounds(), image.Rect(0, 0, 2*w2, h+h2); got != want {
t.Fatalf("bounds0: got %v, want %v", got, want)
}
m1, ok := img1.(*image.Gray)
if !ok {
t.Fatal("decoded PNG image is not a Gray")
}
planes := []struct {
name string
m0Pix []uint8
m0Stride int
m1Rect image.Rectangle
}{
{"Y", m0.Y, m0.YStride, image.Rect(0, 0, w, h)},
{"Cb", m0.Cb, m0.CStride, image.Rect(0*w2, h, 1*w2, h+h2)},
{"Cr", m0.Cr, m0.CStride, image.Rect(1*w2, h, 2*w2, h+h2)},
}
for _, plane := range planes {
dx := plane.m1Rect.Dx()
nDiff, diff := 0, make([]byte, dx)
for j, y := 0, plane.m1Rect.Min.Y; y < plane.m1Rect.Max.Y; j, y = j+1, y+1 {
got := plane.m0Pix[j*plane.m0Stride:][:dx]
want := m1.Pix[y*m1.Stride+plane.m1Rect.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, j, y, hex(got), hex(want), hex(diff))
}
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))
}
}
}
@ -210,5 +213,6 @@ func benchmarkDecode(b *testing.B, filename string) {
}
}
func BenchmarkDecodeVP8(b *testing.B) { benchmarkDecode(b, "yellow_rose.lossy") }
func BenchmarkDecodeVP8L(b *testing.B) { benchmarkDecode(b, "yellow_rose.lossless") }
func BenchmarkDecodeVP8SimpleFilter(b *testing.B) { benchmarkDecode(b, "blue-purple-pink.lossy") }
func BenchmarkDecodeVP8NormalFilter(b *testing.B) { benchmarkDecode(b, "yellow_rose.lossy") }
func BenchmarkDecodeVP8L(b *testing.B) { benchmarkDecode(b, "yellow_rose.lossless") }