From 331597b9f8a7942cbcb233a328301e4d5bf94fb0 Mon Sep 17 00:00:00 2001 From: Tulir Asokan Date: Fri, 11 Jan 2019 23:28:47 +0200 Subject: Switch to Go modules and make other changes --- vendor/golang.org/x/image/vp8/filter.go | 273 -------------------------------- 1 file changed, 273 deletions(-) delete mode 100644 vendor/golang.org/x/image/vp8/filter.go (limited to 'vendor/golang.org/x/image/vp8/filter.go') diff --git a/vendor/golang.org/x/image/vp8/filter.go b/vendor/golang.org/x/image/vp8/filter.go deleted file mode 100644 index e34a811..0000000 --- a/vendor/golang.org/x/image/vp8/filter.go +++ /dev/null @@ -1,273 +0,0 @@ -// 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) -} -- cgit v1.2.3