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-rw-r--r--libswscale/alphablend.c169
1 files changed, 169 insertions, 0 deletions
diff --git a/libswscale/alphablend.c b/libswscale/alphablend.c
new file mode 100644
index 0000000000..b5686599c0
--- /dev/null
+++ b/libswscale/alphablend.c
@@ -0,0 +1,169 @@
+/*
+ * 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;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-09 14:43:31 +0000