ffmpeg/libavutil/imgutils.c

718 lines
23 KiB
C

/*
* 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
*/
/**
* @file
* misc image utilities
*/
#include "avassert.h"
#include "common.h"
#include "imgutils.h"
#include "imgutils_internal.h"
#include "intreadwrite.h"
#include "log.h"
#include "mathematics.h"
#include "mem.h"
#include "pixdesc.h"
#include "rational.h"
void av_image_fill_max_pixsteps(int max_pixsteps[4], int max_pixstep_comps[4],
const AVPixFmtDescriptor *pixdesc)
{
int i;
memset(max_pixsteps, 0, 4*sizeof(max_pixsteps[0]));
if (max_pixstep_comps)
memset(max_pixstep_comps, 0, 4*sizeof(max_pixstep_comps[0]));
for (i = 0; i < 4; i++) {
const AVComponentDescriptor *comp = &(pixdesc->comp[i]);
if (comp->step > max_pixsteps[comp->plane]) {
max_pixsteps[comp->plane] = comp->step;
if (max_pixstep_comps)
max_pixstep_comps[comp->plane] = i;
}
}
}
static inline
int image_get_linesize(int width, int plane,
int max_step, int max_step_comp,
const AVPixFmtDescriptor *desc)
{
int s, shifted_w, linesize;
if (!desc)
return AVERROR(EINVAL);
if (width < 0)
return AVERROR(EINVAL);
s = (max_step_comp == 1 || max_step_comp == 2) ? desc->log2_chroma_w : 0;
shifted_w = ((width + (1 << s) - 1)) >> s;
if (shifted_w && max_step > INT_MAX / shifted_w)
return AVERROR(EINVAL);
linesize = max_step * shifted_w;
if (desc->flags & AV_PIX_FMT_FLAG_BITSTREAM)
linesize = (linesize + 7) >> 3;
return linesize;
}
int av_image_get_linesize(enum AVPixelFormat pix_fmt, int width, int plane)
{
const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
int max_step [4]; /* max pixel step for each plane */
int max_step_comp[4]; /* the component for each plane which has the max pixel step */
if (!desc || desc->flags & AV_PIX_FMT_FLAG_HWACCEL)
return AVERROR(EINVAL);
av_image_fill_max_pixsteps(max_step, max_step_comp, desc);
return image_get_linesize(width, plane, max_step[plane], max_step_comp[plane], desc);
}
int av_image_fill_linesizes(int linesizes[4], enum AVPixelFormat pix_fmt, int width)
{
int i, ret;
const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
int max_step [4]; /* max pixel step for each plane */
int max_step_comp[4]; /* the component for each plane which has the max pixel step */
memset(linesizes, 0, 4*sizeof(linesizes[0]));
if (!desc || desc->flags & AV_PIX_FMT_FLAG_HWACCEL)
return AVERROR(EINVAL);
av_image_fill_max_pixsteps(max_step, max_step_comp, desc);
for (i = 0; i < 4; i++) {
if ((ret = image_get_linesize(width, i, max_step[i], max_step_comp[i], desc)) < 0)
return ret;
linesizes[i] = ret;
}
return 0;
}
int av_image_fill_plane_sizes(size_t sizes[4], enum AVPixelFormat pix_fmt,
int height, const ptrdiff_t linesizes[4])
{
int i, has_plane[4] = { 0 };
const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
memset(sizes , 0, sizeof(sizes[0])*4);
if (!desc || desc->flags & AV_PIX_FMT_FLAG_HWACCEL)
return AVERROR(EINVAL);
if (linesizes[0] > SIZE_MAX / height)
return AVERROR(EINVAL);
sizes[0] = linesizes[0] * (size_t)height;
if (desc->flags & AV_PIX_FMT_FLAG_PAL) {
sizes[1] = 256 * 4; /* palette is stored here as 256 32 bits words */
return 0;
}
for (i = 0; i < 4; i++)
has_plane[desc->comp[i].plane] = 1;
for (i = 1; i < 4 && has_plane[i]; i++) {
int h, s = (i == 1 || i == 2) ? desc->log2_chroma_h : 0;
h = (height + (1 << s) - 1) >> s;
if (linesizes[i] > SIZE_MAX / h)
return AVERROR(EINVAL);
sizes[i] = (size_t)h * linesizes[i];
}
return 0;
}
int av_image_fill_pointers(uint8_t *data[4], enum AVPixelFormat pix_fmt, int height,
uint8_t *ptr, const int linesizes[4])
{
int i, ret;
ptrdiff_t linesizes1[4];
size_t sizes[4];
memset(data , 0, sizeof(data[0])*4);
for (i = 0; i < 4; i++)
linesizes1[i] = linesizes[i];
ret = av_image_fill_plane_sizes(sizes, pix_fmt, height, linesizes1);
if (ret < 0)
return ret;
ret = 0;
for (i = 0; i < 4; i++) {
if (sizes[i] > INT_MAX - ret)
return AVERROR(EINVAL);
ret += sizes[i];
}
if (!ptr)
return ret;
data[0] = ptr;
for (i = 1; i < 4 && sizes[i]; i++)
data[i] = data[i - 1] + sizes[i - 1];
return ret;
}
int avpriv_set_systematic_pal2(uint32_t pal[256], enum AVPixelFormat pix_fmt)
{
int i;
for (i = 0; i < 256; i++) {
int r, g, b;
switch (pix_fmt) {
case AV_PIX_FMT_RGB8:
r = (i>>5 )*36;
g = ((i>>2)&7)*36;
b = (i&3 )*85;
break;
case AV_PIX_FMT_BGR8:
b = (i>>6 )*85;
g = ((i>>3)&7)*36;
r = (i&7 )*36;
break;
case AV_PIX_FMT_RGB4_BYTE:
r = (i>>3 )*255;
g = ((i>>1)&3)*85;
b = (i&1 )*255;
break;
case AV_PIX_FMT_BGR4_BYTE:
b = (i>>3 )*255;
g = ((i>>1)&3)*85;
r = (i&1 )*255;
break;
case AV_PIX_FMT_GRAY8:
r = b = g = i;
break;
default:
return AVERROR(EINVAL);
}
pal[i] = b + (g << 8) + (r << 16) + (0xFFU << 24);
}
return 0;
}
int av_image_alloc(uint8_t *pointers[4], int linesizes[4],
int w, int h, enum AVPixelFormat pix_fmt, int align)
{
const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
int i, ret;
ptrdiff_t linesizes1[4];
size_t total_size, sizes[4];
uint8_t *buf;
if (!desc)
return AVERROR(EINVAL);
if ((ret = av_image_check_size(w, h, 0, NULL)) < 0)
return ret;
if ((ret = av_image_fill_linesizes(linesizes, pix_fmt, align>7 ? FFALIGN(w, 8) : w)) < 0)
return ret;
for (i = 0; i < 4; i++) {
linesizes[i] = FFALIGN(linesizes[i], align);
linesizes1[i] = linesizes[i];
}
if ((ret = av_image_fill_plane_sizes(sizes, pix_fmt, h, linesizes1)) < 0)
return ret;
total_size = align;
for (i = 0; i < 4; i++) {
if (total_size > SIZE_MAX - sizes[i])
return AVERROR(EINVAL);
total_size += sizes[i];
}
buf = av_malloc(total_size);
if (!buf)
return AVERROR(ENOMEM);
if ((ret = av_image_fill_pointers(pointers, pix_fmt, h, buf, linesizes)) < 0) {
av_free(buf);
return ret;
}
if (desc->flags & AV_PIX_FMT_FLAG_PAL) {
avpriv_set_systematic_pal2((uint32_t*)pointers[1], pix_fmt);
if (align < 4) {
av_log(NULL, AV_LOG_ERROR, "Formats with a palette require a minimum alignment of 4\n");
av_free(buf);
return AVERROR(EINVAL);
}
}
if (desc->flags & AV_PIX_FMT_FLAG_PAL && pointers[1] &&
pointers[1] - pointers[0] > linesizes[0] * h) {
/* zero-initialize the padding before the palette */
memset(pointers[0] + linesizes[0] * h, 0,
pointers[1] - pointers[0] - linesizes[0] * h);
}
return ret;
}
typedef struct ImgUtils {
const AVClass *class;
int log_offset;
void *log_ctx;
} ImgUtils;
static const AVClass imgutils_class = {
.class_name = "IMGUTILS",
.item_name = av_default_item_name,
.option = NULL,
.version = LIBAVUTIL_VERSION_INT,
.log_level_offset_offset = offsetof(ImgUtils, log_offset),
.parent_log_context_offset = offsetof(ImgUtils, log_ctx),
};
int av_image_check_size2(unsigned int w, unsigned int h, int64_t max_pixels, enum AVPixelFormat pix_fmt, int log_offset, void *log_ctx)
{
ImgUtils imgutils = {
.class = &imgutils_class,
.log_offset = log_offset,
.log_ctx = log_ctx,
};
int64_t stride = av_image_get_linesize(pix_fmt, w, 0);
if (stride <= 0)
stride = 8LL*w;
stride += 128*8;
if (w==0 || h==0 || w > INT32_MAX || h > INT32_MAX || stride >= INT_MAX || stride*(h + 128ULL) >= INT_MAX) {
av_log(&imgutils, AV_LOG_ERROR, "Picture size %ux%u is invalid\n", w, h);
return AVERROR(EINVAL);
}
if (max_pixels < INT64_MAX) {
if (w*(int64_t)h > max_pixels) {
av_log(&imgutils, AV_LOG_ERROR,
"Picture size %ux%u exceeds specified max pixel count %"PRId64", see the documentation if you wish to increase it\n",
w, h, max_pixels);
return AVERROR(EINVAL);
}
}
return 0;
}
int av_image_check_size(unsigned int w, unsigned int h, int log_offset, void *log_ctx)
{
return av_image_check_size2(w, h, INT64_MAX, AV_PIX_FMT_NONE, log_offset, log_ctx);
}
int av_image_check_sar(unsigned int w, unsigned int h, AVRational sar)
{
int64_t scaled_dim;
if (sar.den <= 0 || sar.num < 0)
return AVERROR(EINVAL);
if (!sar.num || sar.num == sar.den)
return 0;
if (sar.num < sar.den)
scaled_dim = av_rescale_rnd(w, sar.num, sar.den, AV_ROUND_ZERO);
else
scaled_dim = av_rescale_rnd(h, sar.den, sar.num, AV_ROUND_ZERO);
if (scaled_dim > 0)
return 0;
return AVERROR(EINVAL);
}
static void image_copy_plane(uint8_t *dst, ptrdiff_t dst_linesize,
const uint8_t *src, ptrdiff_t src_linesize,
ptrdiff_t bytewidth, int height)
{
if (!dst || !src)
return;
av_assert0(FFABS(src_linesize) >= bytewidth);
av_assert0(FFABS(dst_linesize) >= bytewidth);
for (;height > 0; height--) {
memcpy(dst, src, bytewidth);
dst += dst_linesize;
src += src_linesize;
}
}
void av_image_copy_plane_uc_from(uint8_t *dst, ptrdiff_t dst_linesize,
const uint8_t *src, ptrdiff_t src_linesize,
ptrdiff_t bytewidth, int height)
{
int ret = -1;
#if ARCH_X86
ret = ff_image_copy_plane_uc_from_x86(dst, dst_linesize, src, src_linesize,
bytewidth, height);
#endif
if (ret < 0)
image_copy_plane(dst, dst_linesize, src, src_linesize, bytewidth, height);
}
void av_image_copy_plane(uint8_t *dst, int dst_linesize,
const uint8_t *src, int src_linesize,
int bytewidth, int height)
{
image_copy_plane(dst, dst_linesize, src, src_linesize, bytewidth, height);
}
static void image_copy(uint8_t *const dst_data[4], const ptrdiff_t dst_linesizes[4],
const uint8_t *const src_data[4], const ptrdiff_t src_linesizes[4],
enum AVPixelFormat pix_fmt, int width, int height,
void (*copy_plane)(uint8_t *, ptrdiff_t, const uint8_t *,
ptrdiff_t, ptrdiff_t, int))
{
const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
if (!desc || desc->flags & AV_PIX_FMT_FLAG_HWACCEL)
return;
if (desc->flags & AV_PIX_FMT_FLAG_PAL) {
copy_plane(dst_data[0], dst_linesizes[0],
src_data[0], src_linesizes[0],
width, height);
/* copy the palette */
if ((desc->flags & AV_PIX_FMT_FLAG_PAL) || (dst_data[1] && src_data[1]))
memcpy(dst_data[1], src_data[1], 4*256);
} else {
int i, planes_nb = 0;
for (i = 0; i < desc->nb_components; i++)
planes_nb = FFMAX(planes_nb, desc->comp[i].plane + 1);
for (i = 0; i < planes_nb; i++) {
int h = height;
ptrdiff_t bwidth = av_image_get_linesize(pix_fmt, width, i);
if (bwidth < 0) {
av_log(NULL, AV_LOG_ERROR, "av_image_get_linesize failed\n");
return;
}
if (i == 1 || i == 2) {
h = AV_CEIL_RSHIFT(height, desc->log2_chroma_h);
}
copy_plane(dst_data[i], dst_linesizes[i],
src_data[i], src_linesizes[i],
bwidth, h);
}
}
}
void av_image_copy(uint8_t *const dst_data[4], const int dst_linesizes[4],
const uint8_t * const src_data[4], const int src_linesizes[4],
enum AVPixelFormat pix_fmt, int width, int height)
{
ptrdiff_t dst_linesizes1[4], src_linesizes1[4];
int i;
for (i = 0; i < 4; i++) {
dst_linesizes1[i] = dst_linesizes[i];
src_linesizes1[i] = src_linesizes[i];
}
image_copy(dst_data, dst_linesizes1, src_data, src_linesizes1, pix_fmt,
width, height, image_copy_plane);
}
void av_image_copy_uc_from(uint8_t * const dst_data[4], const ptrdiff_t dst_linesizes[4],
const uint8_t * const src_data[4], const ptrdiff_t src_linesizes[4],
enum AVPixelFormat pix_fmt, int width, int height)
{
image_copy(dst_data, dst_linesizes, src_data, src_linesizes, pix_fmt,
width, height, av_image_copy_plane_uc_from);
}
int av_image_fill_arrays(uint8_t *dst_data[4], int dst_linesize[4],
const uint8_t *src, enum AVPixelFormat pix_fmt,
int width, int height, int align)
{
int ret, i;
ret = av_image_check_size(width, height, 0, NULL);
if (ret < 0)
return ret;
ret = av_image_fill_linesizes(dst_linesize, pix_fmt, width);
if (ret < 0)
return ret;
for (i = 0; i < 4; i++)
dst_linesize[i] = FFALIGN(dst_linesize[i], align);
return av_image_fill_pointers(dst_data, pix_fmt, height, (uint8_t *)src, dst_linesize);
}
int av_image_get_buffer_size(enum AVPixelFormat pix_fmt,
int width, int height, int align)
{
int ret, i;
int linesize[4];
ptrdiff_t aligned_linesize[4];
size_t sizes[4];
const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
if (!desc)
return AVERROR(EINVAL);
ret = av_image_check_size(width, height, 0, NULL);
if (ret < 0)
return ret;
ret = av_image_fill_linesizes(linesize, pix_fmt, width);
if (ret < 0)
return ret;
for (i = 0; i < 4; i++)
aligned_linesize[i] = FFALIGN(linesize[i], align);
ret = av_image_fill_plane_sizes(sizes, pix_fmt, height, aligned_linesize);
if (ret < 0)
return ret;
ret = 0;
for (i = 0; i < 4; i++) {
if (sizes[i] > INT_MAX - ret)
return AVERROR(EINVAL);
ret += sizes[i];
}
return ret;
}
int av_image_copy_to_buffer(uint8_t *dst, int dst_size,
const uint8_t * const src_data[4],
const int src_linesize[4],
enum AVPixelFormat pix_fmt,
int width, int height, int align)
{
int i, j, nb_planes = 0, linesize[4];
int size = av_image_get_buffer_size(pix_fmt, width, height, align);
const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
int ret;
if (size > dst_size || size < 0 || !desc)
return AVERROR(EINVAL);
for (i = 0; i < desc->nb_components; i++)
nb_planes = FFMAX(desc->comp[i].plane, nb_planes);
nb_planes++;
ret = av_image_fill_linesizes(linesize, pix_fmt, width);
av_assert0(ret >= 0); // was checked previously
for (i = 0; i < nb_planes; i++) {
int h, shift = (i == 1 || i == 2) ? desc->log2_chroma_h : 0;
const uint8_t *src = src_data[i];
h = (height + (1 << shift) - 1) >> shift;
for (j = 0; j < h; j++) {
memcpy(dst, src, linesize[i]);
dst += FFALIGN(linesize[i], align);
src += src_linesize[i];
}
}
if (desc->flags & AV_PIX_FMT_FLAG_PAL) {
uint32_t *d32 = (uint32_t *)dst;
for (i = 0; i<256; i++)
AV_WL32(d32 + i, AV_RN32(src_data[1] + 4*i));
}
return size;
}
// Fill dst[0..dst_size] with the bytes in clear[0..clear_size]. The clear
// bytes are repeated until dst_size is reached. If dst_size is unaligned (i.e.
// dst_size%clear_size!=0), the remaining data will be filled with the beginning
// of the clear data only.
static void memset_bytes(uint8_t *dst, size_t dst_size, uint8_t *clear,
size_t clear_size)
{
int same = 1;
int i;
if (!clear_size)
return;
// Reduce to memset() if possible.
for (i = 0; i < clear_size; i++) {
if (clear[i] != clear[0]) {
same = 0;
break;
}
}
if (same)
clear_size = 1;
if (clear_size == 1) {
memset(dst, clear[0], dst_size);
} else {
if (clear_size > dst_size)
clear_size = dst_size;
memcpy(dst, clear, clear_size);
av_memcpy_backptr(dst + clear_size, clear_size, dst_size - clear_size);
}
}
// Maximum size in bytes of a plane element (usually a pixel, or multiple pixels
// if it's a subsampled packed format).
#define MAX_BLOCK_SIZE 32
int av_image_fill_color(uint8_t * const dst_data[4], const ptrdiff_t dst_linesize[4],
enum AVPixelFormat pix_fmt, const uint32_t color[4],
int width, int height, int flags)
{
const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
int nb_planes = av_pix_fmt_count_planes(pix_fmt);
// A pixel or a group of pixels on each plane, with a value that represents the color.
// Consider e.g. AV_PIX_FMT_UYVY422 for non-trivial cases.
uint8_t clear_block[4][MAX_BLOCK_SIZE] = {{0}}; // clear padding with 0
int clear_block_size[4] = {0};
ptrdiff_t plane_line_bytes[4] = {0};
int bitstream;
int plane, c;
if (!desc || nb_planes < 1 || nb_planes > 4 || desc->flags & AV_PIX_FMT_FLAG_HWACCEL)
return AVERROR(EINVAL);
bitstream = !!(desc->flags & AV_PIX_FMT_FLAG_BITSTREAM);
for (c = 0; c < desc->nb_components; c++) {
const AVComponentDescriptor comp = desc->comp[c];
// We try to operate on entire non-subsampled pixel groups (for
// AV_PIX_FMT_UYVY422 this would mean two consecutive pixels).
clear_block_size[comp.plane] = FFMAX(clear_block_size[comp.plane], comp.step);
if (clear_block_size[comp.plane] > MAX_BLOCK_SIZE)
return AVERROR(EINVAL);
}
// Create a byte array for clearing 1 pixel (sometimes several pixels).
for (c = 0; c < desc->nb_components; c++) {
const AVComponentDescriptor comp = desc->comp[c];
// (Multiple pixels happen e.g. with AV_PIX_FMT_UYVY422.)
int w = (bitstream ? 8 : 1) * clear_block_size[comp.plane] / comp.step;
uint8_t *c_data[4];
const int c_linesize[4] = {0};
uint32_t src_array[MAX_BLOCK_SIZE];
int x;
if (comp.depth > 32)
return AVERROR(EINVAL);
if (w < 1)
return AVERROR(EINVAL);
for (x = 0; x < w; x++)
src_array[x] = color[c];
for (x = 0; x < 4; x++)
c_data[x] = &clear_block[x][0];
av_write_image_line2(src_array, c_data, c_linesize, desc, 0, 0, c, w, 4);
}
for (plane = 0; plane < nb_planes; plane++) {
plane_line_bytes[plane] = av_image_get_linesize(pix_fmt, width, plane);
if (plane_line_bytes[plane] < 0)
return AVERROR(EINVAL);
}
if (!dst_data)
return 0;
for (plane = 0; plane < nb_planes; plane++) {
size_t bytewidth = plane_line_bytes[plane];
uint8_t *data = dst_data[plane];
int chroma_div = plane == 1 || plane == 2 ? desc->log2_chroma_h : 0;
int plane_h = ((height + ( 1 << chroma_div) - 1)) >> chroma_div;
for (; plane_h > 0; plane_h--) {
memset_bytes(data, bytewidth, &clear_block[plane][0], clear_block_size[plane]);
data += dst_linesize[plane];
}
}
return 0;
}
int av_image_fill_black(uint8_t * const dst_data[4], const ptrdiff_t dst_linesize[4],
enum AVPixelFormat pix_fmt, enum AVColorRange range,
int width, int height)
{
const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
int nb_planes = av_pix_fmt_count_planes(pix_fmt);
int rgb, xyz, pal, limited, alpha, fltp;
uint32_t colors[4] = {0};
if (!desc || nb_planes < 1 || nb_planes > 4 || desc->flags & AV_PIX_FMT_FLAG_HWACCEL)
return AVERROR(EINVAL);
rgb = !!(desc->flags & AV_PIX_FMT_FLAG_RGB);
xyz = !!(desc->flags & AV_PIX_FMT_FLAG_XYZ);
pal = !!(desc->flags & AV_PIX_FMT_FLAG_PAL);
limited = !rgb && !xyz && !pal && range != AVCOL_RANGE_JPEG;
alpha = !pal && !!(desc->flags & AV_PIX_FMT_FLAG_ALPHA);
fltp = !!(desc->flags & AV_PIX_FMT_FLAG_FLOAT);
for (int c = 0; c < desc->nb_components; c++) {
const AVComponentDescriptor comp = desc->comp[c];
uint32_t color = 0;
if (comp.depth > 32)
return AVERROR(EINVAL);
if (pix_fmt == AV_PIX_FMT_MONOWHITE) {
color = 1;
} else if (c + 1 == desc->nb_components && alpha) {
// (Assume even limited YUV uses full range alpha.)
if (fltp) {
if (comp.depth != 16 && comp.depth != 32)
return AVERROR(EINVAL);
color = (comp.depth == 16 ? 0x3C00 : 0x3F800000); // 1.0
} else {
color = (comp.depth == 32 ? 0 : (1 << comp.depth)) - 1;
}
} else if (c == 0 && limited && comp.depth > 1) {
if (comp.depth < 8 || (fltp && comp.depth != 16 && comp.depth != 32))
return AVERROR(EINVAL);
if (fltp)
color = (comp.depth == 16 ? 0x2C00 : 0x3D800000); // 0.0625
else
color = 16 << (comp.depth - 8);
} else if ((c == 1 || c == 2) && !rgb && !xyz) {
if (comp.depth < 8 || fltp && comp.depth != 16 && comp.depth != 32)
return AVERROR(EINVAL);
if (fltp)
color = (comp.depth == 16 ? 0x3800 : 0x3F000000); // 0.5
else
color = 128 << (comp.depth - 8);
}
colors[c] = color;
}
return av_image_fill_color(dst_data, dst_linesize, pix_fmt, colors, width, height, 0);
}