From ff48f4aad70031a689bc8f136e78e8bb71cdd69f Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Thu, 30 Sep 2021 19:00:56 +0200 Subject: [PATCH] swscale/alphablend: Fix slice handling Reviewed-by: Paul B Mahol Signed-off-by: Michael Niedermayer (cherry picked from commit 06d67265881249566f385309e2fb5a9449720b6e) Signed-off-by: Michael Niedermayer --- libswscale/alphablend.c | 32 +++++++++++++++++--------------- 1 file changed, 17 insertions(+), 15 deletions(-) diff --git a/libswscale/alphablend.c b/libswscale/alphablend.c index b5686599c0..b5967c889b 100644 --- a/libswscale/alphablend.c +++ b/libswscale/alphablend.c @@ -26,7 +26,7 @@ int ff_sws_alphablendaway(SwsContext *c, const uint8_t *src[], { const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(c->srcFormat); int nb_components = desc->nb_components; - int plane, x, y; + int plane, x, ysrc; int plane_count = isGray(c->srcFormat) ? 1 : 3; int sixteen_bits = desc->comp[0].depth >= 9; unsigned off = 1<<(desc->comp[0].depth - 1); @@ -50,14 +50,15 @@ int ff_sws_alphablendaway(SwsContext *c, const uint8_t *src[], 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 < AV_CEIL_RSHIFT(srcSliceH, y_subsample); y++) { + for (ysrc = 0; ysrc < AV_CEIL_RSHIFT(srcSliceH, y_subsample); ysrc++) { + int y = ysrc + (srcSliceY >> y_subsample); if (x_subsample || y_subsample) { int alpha; unsigned u; if (sixteen_bits) { ptrdiff_t alpha_step = srcStride[plane_count] >> 1; - const uint16_t *s = (const uint16_t *)(src[plane ] + srcStride[plane ] * y); - const uint16_t *a = (const uint16_t *)(src[plane_count] + (srcStride[plane_count] * y << y_subsample)); + const uint16_t *s = (const uint16_t *)(src[plane ] + srcStride[plane ] * ysrc); + const uint16_t *a = (const uint16_t *)(src[plane_count] + (srcStride[plane_count] * ysrc << y_subsample)); uint16_t *d = ( uint16_t *)(dst[plane ] + dstStride[plane ] * y); if ((!isBE(c->srcFormat)) == !HAVE_BIGENDIAN) { for (x = 0; x < w; x++) { @@ -82,8 +83,8 @@ int ff_sws_alphablendaway(SwsContext *c, const uint8_t *src[], } } 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); + const uint8_t *s = src[plane ] + srcStride[plane] * ysrc; + const uint8_t *a = src[plane_count] + (srcStride[plane_count] * ysrc << y_subsample); uint8_t *d = dst[plane ] + dstStride[plane] * y; for (x = 0; x < w; x++) { if (y_subsample) { @@ -97,8 +98,8 @@ int ff_sws_alphablendaway(SwsContext *c, const uint8_t *src[], } } else { if (sixteen_bits) { - const uint16_t *s = (const uint16_t *)(src[plane ] + srcStride[plane ] * y); - const uint16_t *a = (const uint16_t *)(src[plane_count] + srcStride[plane_count] * y); + const uint16_t *s = (const uint16_t *)(src[plane ] + srcStride[plane ] * ysrc); + const uint16_t *a = (const uint16_t *)(src[plane_count] + srcStride[plane_count] * ysrc); uint16_t *d = ( uint16_t *)(dst[plane ] + dstStride[plane ] * y); if ((!isBE(c->srcFormat)) == !HAVE_BIGENDIAN) { for (x = 0; x < w; x++) { @@ -113,8 +114,8 @@ int ff_sws_alphablendaway(SwsContext *c, const uint8_t *src[], } } } else { - const uint8_t *s = src[plane ] + srcStride[plane] * y; - const uint8_t *a = src[plane_count] + srcStride[plane_count] * y; + const uint8_t *s = src[plane ] + srcStride[plane] * ysrc; + const uint8_t *a = src[plane_count] + srcStride[plane_count] * ysrc; uint8_t *d = dst[plane ] + dstStride[plane] * y; for (x = 0; x < w; x++) { unsigned u = s[x]*a[x] + target_table[((x^y)>>5)&1][plane]*(255-a[x]) + 128; @@ -127,10 +128,11 @@ int ff_sws_alphablendaway(SwsContext *c, const uint8_t *src[], } else { int alpha_pos = desc->comp[plane_count].offset; int w = c->srcW; - for (y = srcSliceY; y < srcSliceH; y++) { + for (ysrc = 0; ysrc < srcSliceH; ysrc++) { + int y = ysrc + srcSliceY; if (sixteen_bits) { - const uint16_t *s = (const uint16_t *)(src[0] + srcStride[0] * y + 2*!alpha_pos); - const uint16_t *a = (const uint16_t *)(src[0] + srcStride[0] * y + alpha_pos); + const uint16_t *s = (const uint16_t *)(src[0] + srcStride[0] * ysrc + 2*!alpha_pos); + const uint16_t *a = (const uint16_t *)(src[0] + srcStride[0] * ysrc + alpha_pos); uint16_t *d = ( uint16_t *)(dst[0] + dstStride[0] * y); if ((!isBE(c->srcFormat)) == !HAVE_BIGENDIAN) { for (x = 0; x < w; x++) { @@ -151,8 +153,8 @@ int ff_sws_alphablendaway(SwsContext *c, const uint8_t *src[], } } } else { - const uint8_t *s = src[0] + srcStride[0] * y + !alpha_pos; - const uint8_t *a = src[0] + srcStride[0] * y + alpha_pos; + const uint8_t *s = src[0] + srcStride[0] * ysrc + !alpha_pos; + const uint8_t *a = src[0] + srcStride[0] * ysrc + alpha_pos; uint8_t *d = dst[0] + dstStride[0] * y; for (x = 0; x < w; x++) { for (plane = 0; plane < plane_count; plane++) {