diff options
Diffstat (limited to 'libgo/go/image/ycbcr.go')
| -rw-r--r-- | libgo/go/image/ycbcr.go | 29 |
1 files changed, 25 insertions, 4 deletions
diff --git a/libgo/go/image/ycbcr.go b/libgo/go/image/ycbcr.go index 7c773f2f0a4..93c354b33b4 100644 --- a/libgo/go/image/ycbcr.go +++ b/libgo/go/image/ycbcr.go @@ -16,6 +16,8 @@ const ( YCbCrSubsampleRatio422 YCbCrSubsampleRatio420 YCbCrSubsampleRatio440 + YCbCrSubsampleRatio411 + YCbCrSubsampleRatio410 ) func (s YCbCrSubsampleRatio) String() string { @@ -28,6 +30,10 @@ func (s YCbCrSubsampleRatio) String() string { return "YCbCrSubsampleRatio420" case YCbCrSubsampleRatio440: return "YCbCrSubsampleRatio440" + case YCbCrSubsampleRatio411: + return "YCbCrSubsampleRatio411" + case YCbCrSubsampleRatio410: + return "YCbCrSubsampleRatio410" } return "YCbCrSubsampleRatioUnknown" } @@ -43,6 +49,8 @@ func (s YCbCrSubsampleRatio) String() string { // For 4:2:2, CStride == YStride/2 && len(Cb) == len(Cr) == len(Y)/2. // For 4:2:0, CStride == YStride/2 && len(Cb) == len(Cr) == len(Y)/4. // For 4:4:0, CStride == YStride/1 && len(Cb) == len(Cr) == len(Y)/2. +// For 4:1:1, CStride == YStride/4 && len(Cb) == len(Cr) == len(Y)/4. +// For 4:1:0, CStride == YStride/4 && len(Cb) == len(Cr) == len(Y)/8. type YCbCr struct { Y, Cb, Cr []uint8 YStride int @@ -92,6 +100,10 @@ func (p *YCbCr) COffset(x, y int) int { return (y/2-p.Rect.Min.Y/2)*p.CStride + (x/2 - p.Rect.Min.X/2) case YCbCrSubsampleRatio440: return (y/2-p.Rect.Min.Y/2)*p.CStride + (x - p.Rect.Min.X) + case YCbCrSubsampleRatio411: + return (y-p.Rect.Min.Y)*p.CStride + (x/4 - p.Rect.Min.X/4) + case YCbCrSubsampleRatio410: + return (y/2-p.Rect.Min.Y/2)*p.CStride + (x/4 - p.Rect.Min.X/4) } // Default to 4:4:4 subsampling. return (y-p.Rect.Min.Y)*p.CStride + (x - p.Rect.Min.X) @@ -139,16 +151,25 @@ func NewYCbCr(r Rectangle, subsampleRatio YCbCrSubsampleRatio) *YCbCr { case YCbCrSubsampleRatio440: cw = w ch = (r.Max.Y+1)/2 - r.Min.Y/2 + case YCbCrSubsampleRatio411: + cw = (r.Max.X+3)/4 - r.Min.X/4 + ch = h + case YCbCrSubsampleRatio410: + cw = (r.Max.X+3)/4 - r.Min.X/4 + ch = (r.Max.Y+1)/2 - r.Min.Y/2 default: // Default to 4:4:4 subsampling. cw = w ch = h } - b := make([]byte, w*h+2*cw*ch) + i0 := w*h + 0*cw*ch + i1 := w*h + 1*cw*ch + i2 := w*h + 2*cw*ch + b := make([]byte, i2) return &YCbCr{ - Y: b[:w*h], - Cb: b[w*h+0*cw*ch : w*h+1*cw*ch], - Cr: b[w*h+1*cw*ch : w*h+2*cw*ch], + Y: b[:i0:i0], + Cb: b[i0:i1:i1], + Cr: b[i1:i2:i2], SubsampleRatio: subsampleRatio, YStride: w, CStride: cw, |