ffmpeg | branch: master | Niklas Haas <g...@haasn.dev> | Tue Dec 17 13:23:14 2024 +0100| [095f8038fa9180842cd38d4d61c7c47a02aad9ed] | committer: Niklas Haas
swscale/output: fix bilinear yuv2rgb chroma interpolation These functions were divided into two special cases; one assuming that uvalpha == 0, and the other assuming that uvalpha == 2048. This worked fine for simple 2x chroma upscaling but broke for e.g. yuv410p, non-centered chroma, or other special cases that involved non-aligned chroma filters. Fix it by instead dividing this check into two cases, a uvalpha==0 fast path and a uvalpha>0 general path. Instead of (A+B)/2 the general path now multiplies in the true uvalpha weight. I tried preserving the old fast path for the case of uvalpha == 2048, but this was significantly slower in practise versus having just one general path. However, we still need a uvalpha == 0 path for the unscaled case. Fixes: ticket #5083 Signed-off-by: Niklas Haas <g...@haasn.dev> Sponsored-by: Sovereign Tech Fund > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=095f8038fa9180842cd38d4d61c7c47a02aad9ed --- libswscale/output.c | 36 ++++++++++++++++++++++++------------ 1 file changed, 24 insertions(+), 12 deletions(-) diff --git a/libswscale/output.c b/libswscale/output.c index 656419b5c7..8407cc0abb 100644 --- a/libswscale/output.c +++ b/libswscale/output.c @@ -1206,7 +1206,7 @@ yuv2rgba64_1_c_template(SwsInternal *c, const int32_t *buf0, int i; int A1 = 0xffff<<14, A2= 0xffff<<14; - if (uvalpha < 2048) { + if (uvalpha == 0) { for (i = 0; i < ((dstW + 1) >> 1); i++) { SUINT Y1 = (buf0[i * 2] ) >> 2; SUINT Y2 = (buf0[i * 2 + 1]) >> 2; @@ -1253,11 +1253,14 @@ yuv2rgba64_1_c_template(SwsInternal *c, const int32_t *buf0, } else { const int32_t *ubuf1 = ubuf[1], *vbuf1 = vbuf[1]; int A1 = 0xffff<<14, A2 = 0xffff<<14; + int uvalpha1 = 4096 - uvalpha; + av_assert2(uvalpha <= 4096U); + for (i = 0; i < ((dstW + 1) >> 1); i++) { SUINT Y1 = (buf0[i * 2] ) >> 2; SUINT Y2 = (buf0[i * 2 + 1]) >> 2; - int U = (ubuf0[i] + ubuf1[i] - (128 << 12)) >> 3; - int V = (vbuf0[i] + vbuf1[i] - (128 << 12)) >> 3; + int U = (ubuf0[i] * uvalpha1 + ubuf1[i] * uvalpha - (128 << 23)) >> 14; + int V = (vbuf0[i] * uvalpha1 + vbuf1[i] * uvalpha - (128 << 23)) >> 14; int R, G, B; Y1 -= c->yuv2rgb_y_offset; @@ -1428,7 +1431,7 @@ yuv2rgba64_full_1_c_template(SwsInternal *c, const int32_t *buf0, int i; int A = 0xffff<<14; - if (uvalpha < 2048) { + if (uvalpha == 0) { for (i = 0; i < dstW; i++) { SUINT Y = (buf0[i]) >> 2; int U = (ubuf0[i] - (128 << 11)) >> 2; @@ -1461,11 +1464,14 @@ yuv2rgba64_full_1_c_template(SwsInternal *c, const int32_t *buf0, } } else { const int32_t *ubuf1 = ubuf[1], *vbuf1 = vbuf[1]; + int uvalpha1 = 4096 - uvalpha; int A = 0xffff<<14; + av_assert2(uvalpha <= 4096U); + for (i = 0; i < dstW; i++) { SUINT Y = (buf0[i] ) >> 2; - int U = (ubuf0[i] + ubuf1[i] - (128 << 12)) >> 3; - int V = (vbuf0[i] + vbuf1[i] - (128 << 12)) >> 3; + int U = (ubuf0[i] * uvalpha1 + ubuf1[i] * uvalpha - (128 << 23)) >> 14; + int V = (vbuf0[i] * uvalpha1 + vbuf1[i] * uvalpha - (128 << 23)) >> 14; int R, G, B; Y -= c->yuv2rgb_y_offset; @@ -1813,7 +1819,7 @@ yuv2rgb_1_c_template(SwsInternal *c, const int16_t *buf0, const int16_t *ubuf0 = ubuf[0], *vbuf0 = vbuf[0]; int i; - if (uvalpha < 2048) { + if (uvalpha == 0) { for (i = 0; i < ((dstW + 1) >> 1); i++) { int Y1 = (buf0[i * 2 ] + 64) >> 7; int Y2 = (buf0[i * 2 + 1] + 64) >> 7; @@ -1836,11 +1842,14 @@ yuv2rgb_1_c_template(SwsInternal *c, const int16_t *buf0, } } else { const int16_t *ubuf1 = ubuf[1], *vbuf1 = vbuf[1]; + int uvalpha1 = 4096 - uvalpha; + av_assert2(uvalpha <= 4096U); + for (i = 0; i < ((dstW + 1) >> 1); i++) { int Y1 = (buf0[i * 2 ] + 64) >> 7; int Y2 = (buf0[i * 2 + 1] + 64) >> 7; - int U = (ubuf0[i] + ubuf1[i] + 128) >> 8; - int V = (vbuf0[i] + vbuf1[i] + 128) >> 8; + int U = (ubuf0[i] * uvalpha1 + ubuf1[i] * uvalpha + (128 << 11)) >> 19; + int V = (vbuf0[i] * uvalpha1 + vbuf1[i] * uvalpha + (128 << 11)) >> 19; int A1, A2; const void *r = c->table_rV[V + YUVRGB_TABLE_HEADROOM], *g = (c->table_gU[U + YUVRGB_TABLE_HEADROOM] + c->table_gV[V + YUVRGB_TABLE_HEADROOM]), @@ -2189,7 +2198,7 @@ yuv2rgb_full_1_c_template(SwsInternal *c, const int16_t *buf0, || target == AV_PIX_FMT_BGR8 || target == AV_PIX_FMT_RGB8) step = 1; - if (uvalpha < 2048) { + if (uvalpha == 0) { int A = 0; //init to silence warning for (i = 0; i < dstW; i++) { int Y = buf0[i] * 4; @@ -2208,10 +2217,13 @@ yuv2rgb_full_1_c_template(SwsInternal *c, const int16_t *buf0, } else { const int16_t *ubuf1 = ubuf[1], *vbuf1 = vbuf[1]; int A = 0; //init to silence warning + int uvalpha1 = 4096 - uvalpha; + av_assert2(uvalpha <= 4096U); + for (i = 0; i < dstW; i++) { int Y = buf0[i] * 4; - int U = (ubuf0[i] + ubuf1[i] - (128<<8)) * 2; - int V = (vbuf0[i] + vbuf1[i] - (128<<8)) * 2; + int U = (ubuf0[i] * uvalpha1 + ubuf1[i] * uvalpha - (128 << 19)) >> 10; + int V = (vbuf0[i] * uvalpha1 + vbuf1[i] * uvalpha - (128 << 19)) >> 10; if (hasAlpha) { A = (abuf0[i] + 64) >> 7; _______________________________________________ ffmpeg-cvslog mailing list ffmpeg-cvslog@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog To unsubscribe, visit link above, or email ffmpeg-cvslog-requ...@ffmpeg.org with subject "unsubscribe".
