/* * Copyright (C) 2015 Michael Niedermayer <michaelni@gmx.at> * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include "swscale_internal.h" int ff_sws_alphablendaway(SwsContext *c, const uint8_t *src[], int srcStride[], int srcSliceY, int srcSliceH, uint8_t *dst[], int dstStride[]) { const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(c->srcFormat); int nb_components = desc->nb_components; int plane, x, y; int plane_count = isGray(c->srcFormat) ? 1 : 3; int sixteen_bits = desc->comp[0].depth >= 9; unsigned off = 1<<(desc->comp[0].depth - 1); unsigned shift = desc->comp[0].depth; unsigned max = (1<<shift) - 1; int target_table[2][3]; for (plane = 0; plane < plane_count; plane++) { int a = 0, b = 0; if (c->alphablend == SWS_ALPHA_BLEND_CHECKERBOARD) { a = (1<<(desc->comp[0].depth - 1))/2; b = 3*(1<<(desc->comp[0].depth-1))/2; } target_table[0][plane] = plane && !(desc->flags & AV_PIX_FMT_FLAG_RGB) ? 1<<(desc->comp[0].depth - 1) : a; target_table[1][plane] = plane && !(desc->flags & AV_PIX_FMT_FLAG_RGB) ? 1<<(desc->comp[0].depth - 1) : b; } av_assert0(plane_count == nb_components - 1); 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 < AV_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 = (const uint16_t *)(src[plane ] + srcStride[plane ] * y); const uint16_t *a = (const uint16_t *)(src[plane_count] + (srcStride[plane_count] * y << y_subsample)); uint16_t *d = ( uint16_t *)(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 = (const uint16_t *)(src[plane ] + srcStride[plane ] * y); const uint16_t *a = (const uint16_t *)(src[plane_count] + srcStride[plane_count] * y); uint16_t *d = ( uint16_t *)(dst[plane ] + dstStride[plane ] * y); if ((!isBE(c->srcFormat)) == !HAVE_BIGENDIAN) { for (x = 0; x < w; x++) { unsigned u = s[x]*a[x] + target_table[((x^y)>>5)&1][plane]*(max-a[x]) + off; d[x] = av_clip((u + (u >> shift)) >> shift, 0, max); } } else { for (x = 0; x < w; x++) { unsigned aswap =av_bswap16(a[x]); unsigned u = av_bswap16(s[x])*aswap + target_table[((x^y)>>5)&1][plane]*(max-aswap) + off; d[x] = av_clip((u + (u >> shift)) >> shift, 0, max); } } } else { const uint8_t *s = src[plane ] + srcStride[plane] * y; const uint8_t *a = src[plane_count] + srcStride[plane_count] * y; 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; d[x] = (257*u) >> 16; } } } } } } else { int alpha_pos = desc->comp[plane_count].offset; int w = c->srcW; for (y = srcSliceY; y < srcSliceH; y++) { 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); uint16_t *d = ( uint16_t *)(dst[0] + dstStride[0] * y); if ((!isBE(c->srcFormat)) == !HAVE_BIGENDIAN) { for (x = 0; x < w; x++) { for (plane = 0; plane < plane_count; plane++) { int x_index = (plane_count + 1) * x; unsigned u = s[x_index + plane]*a[x_index] + target_table[((x^y)>>5)&1][plane]*(max-a[x_index]) + off; d[plane_count*x + plane] = av_clip((u + (u >> shift)) >> shift, 0, max); } } } else { for (x = 0; x < w; x++) { for (plane = 0; plane < plane_count; plane++) { int x_index = (plane_count + 1) * x; unsigned aswap =av_bswap16(a[x_index]); unsigned u = av_bswap16(s[x_index + plane])*aswap + target_table[((x^y)>>5)&1][plane]*(max-aswap) + off; d[plane_count*x + plane] = av_clip((u + (u >> shift)) >> shift, 0, max); } } } } else { const uint8_t *s = src[0] + srcStride[0] * y + !alpha_pos; const uint8_t *a = src[0] + srcStride[0] * y + alpha_pos; uint8_t *d = dst[0] + dstStride[0] * y; for (x = 0; x < w; x++) { for (plane = 0; plane < plane_count; plane++) { int x_index = (plane_count + 1) * x; unsigned u = s[x_index + plane]*a[x_index] + target_table[((x^y)>>5)&1][plane]*(255-a[x_index]) + 128; d[plane_count*x + plane] = (257*u) >> 16; } } } } } return 0; }