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| author | Michael Niedermayer <michael@niedermayer.cc> | 2015-08-09 17:48:58 +0200 |
|---|---|---|
| committer | Michael Niedermayer <michael@niedermayer.cc> | 2015-08-09 18:04:46 +0200 |
| commit | 0f9d46b70d2ac6ca7fd883f19f8aa540a55ae9b8 (patch) | |
| tree | 01bf9b6eb4b6c578a2da895cb7071650008471fb /libswscale/alphablend.c | |
| parent | c5ebeaa3085bef608a1ec76e8e6b24e6e98c428a (diff) | |
| download | ffmpeg-0f9d46b70d2ac6ca7fd883f19f8aa540a55ae9b8.tar.gz | |
swscale/alphablend: Support chroma subsampling
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Diffstat (limited to 'libswscale/alphablend.c')
| -rw-r--r-- | libswscale/alphablend.c | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/libswscale/alphablend.c b/libswscale/alphablend.c index 3bd71bac96..1aaef70bf7 100644 --- a/libswscale/alphablend.c +++ b/libswscale/alphablend.c @@ -48,8 +48,54 @@ int ff_sws_alphablendaway(SwsContext *c, const uint8_t *src[], if (desc->flags & AV_PIX_FMT_FLAG_PLANAR) { for (plane = 0; plane < plane_count; plane++) { int w = plane ? c->chrSrcW : c->srcW; + int x_subsample = plane ? desc->log2_chroma_w: 0; int y_subsample = plane ? desc->log2_chroma_h: 0; for (y = srcSliceY >> y_subsample; y < FF_CEIL_RSHIFT(srcSliceH, y_subsample); y++) { + if (x_subsample || y_subsample) { + int alpha; + unsigned u; + if (sixteen_bits) { + ptrdiff_t alpha_step = srcStride[plane_count] >> 1; + const uint16_t *s = src[plane ] + srcStride[plane] * y; + const uint16_t *a = src[plane_count] + (srcStride[plane_count] * y << y_subsample); + uint16_t *d = dst[plane ] + dstStride[plane] * y; + if ((!isBE(c->srcFormat)) == !HAVE_BIGENDIAN) { + for (x = 0; x < w; x++) { + if (y_subsample) { + alpha = (a[2*x] + a[2*x + 1] + 2 + + a[2*x + alpha_step] + a[2*x + alpha_step + 1]) >> 2; + } else + alpha = (a[2*x] + a[2*x + 1]) >> 1; + u = s[x]*alpha + target_table[((x^y)>>5)&1][plane]*(max-alpha) + off; + d[x] = av_clip((u + (u >> shift)) >> shift, 0, max); + } + } else { + for (x = 0; x < w; x++) { + if (y_subsample) { + alpha = (av_bswap16(a[2*x]) + av_bswap16(a[2*x + 1]) + 2 + + av_bswap16(a[2*x + alpha_step]) + av_bswap16(a[2*x + alpha_step + 1])) >> 2; + } else + alpha = (av_bswap16(a[2*x]) + av_bswap16(a[2*x + 1])) >> 1; + u = av_bswap16(s[x])*alpha + target_table[((x^y)>>5)&1][plane]*(max-alpha) + off; + d[x] = av_clip((u + (u >> shift)) >> shift, 0, max); + } + } + } else { + ptrdiff_t alpha_step = srcStride[plane_count]; + const uint8_t *s = src[plane ] + srcStride[plane] * y; + const uint8_t *a = src[plane_count] + (srcStride[plane_count] * y << y_subsample); + uint8_t *d = dst[plane ] + dstStride[plane] * y; + for (x = 0; x < w; x++) { + if (y_subsample) { + alpha = (a[2*x] + a[2*x + 1] + 2 + + a[2*x + alpha_step] + a[2*x + alpha_step + 1]) >> 2; + } else + alpha = (a[2*x] + a[2*x + 1]) >> 1; + u = s[x]*alpha + target_table[((x^y)>>5)&1][plane]*(255-alpha) + 128; + d[x] = (257*u) >> 16; + } + } + } else { if (sixteen_bits) { const uint16_t *s = src[plane ] + srcStride[plane] * y; const uint16_t *a = src[plane_count] + srcStride[plane_count] * y; @@ -75,6 +121,7 @@ int ff_sws_alphablendaway(SwsContext *c, const uint8_t *src[], d[x] = (257*u) >> 16; } } + } } } } else { |