946 lines
28 KiB
C
946 lines
28 KiB
C
/*
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* PNG image format
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* Copyright (c) 2003 Fabrice Bellard.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include "avcodec.h"
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/* TODO:
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* - add 2, 4 and 16 bit depth support
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* - use filters when generating a png (better compression)
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*/
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#ifdef CONFIG_ZLIB
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#include <zlib.h>
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//#define DEBUG
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#define PNG_COLOR_MASK_PALETTE 1
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#define PNG_COLOR_MASK_COLOR 2
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#define PNG_COLOR_MASK_ALPHA 4
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#define PNG_COLOR_TYPE_GRAY 0
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#define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
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#define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
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#define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
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#define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
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#define PNG_FILTER_VALUE_NONE 0
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#define PNG_FILTER_VALUE_SUB 1
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#define PNG_FILTER_VALUE_UP 2
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#define PNG_FILTER_VALUE_AVG 3
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#define PNG_FILTER_VALUE_PAETH 4
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#define PNG_IHDR 0x0001
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#define PNG_IDAT 0x0002
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#define PNG_ALLIMAGE 0x0004
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#define PNG_PLTE 0x0008
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#define NB_PASSES 7
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#define IOBUF_SIZE 4096
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typedef struct PNGContext {
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uint8_t *bytestream;
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uint8_t *bytestream_start;
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uint8_t *bytestream_end;
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AVFrame picture;
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int state;
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int width, height;
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int bit_depth;
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int color_type;
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int compression_type;
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int interlace_type;
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int filter_type;
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int channels;
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int bits_per_pixel;
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int bpp;
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uint8_t *image_buf;
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int image_linesize;
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uint32_t palette[256];
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uint8_t *crow_buf;
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uint8_t *last_row;
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uint8_t *tmp_row;
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int pass;
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int crow_size; /* compressed row size (include filter type) */
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int row_size; /* decompressed row size */
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int pass_row_size; /* decompress row size of the current pass */
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int y;
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z_stream zstream;
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uint8_t buf[IOBUF_SIZE];
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} PNGContext;
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static unsigned int get32(uint8_t **b){
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(*b) += 4;
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return ((*b)[-4]<<24) + ((*b)[-3]<<16) + ((*b)[-2]<<8) + (*b)[-1];
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}
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static void put32(uint8_t **b, unsigned int v){
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*(*b)++= v>>24;
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*(*b)++= v>>16;
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*(*b)++= v>>8;
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*(*b)++= v;
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}
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static const uint8_t pngsig[8] = {137, 80, 78, 71, 13, 10, 26, 10};
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/* Mask to determine which y pixels are valid in a pass */
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static const uint8_t png_pass_ymask[NB_PASSES] = {
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0x80, 0x80, 0x08, 0x88, 0x22, 0xaa, 0x55,
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};
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/* Mask to determine which y pixels can be written in a pass */
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static const uint8_t png_pass_dsp_ymask[NB_PASSES] = {
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0xff, 0xff, 0x0f, 0xcc, 0x33, 0xff, 0x55,
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};
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/* minimum x value */
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static const uint8_t png_pass_xmin[NB_PASSES] = {
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0, 4, 0, 2, 0, 1, 0
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};
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/* x shift to get row width */
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static const uint8_t png_pass_xshift[NB_PASSES] = {
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3, 3, 2, 2, 1, 1, 0
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};
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/* Mask to determine which pixels are valid in a pass */
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static const uint8_t png_pass_mask[NB_PASSES] = {
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0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff
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};
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/* Mask to determine which pixels to overwrite while displaying */
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static const uint8_t png_pass_dsp_mask[NB_PASSES] = {
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0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff
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};
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#if 0
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static int png_probe(AVProbeData *pd)
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{
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if (pd->buf_size >= 8 &&
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memcmp(pd->buf, pngsig, 8) == 0)
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return AVPROBE_SCORE_MAX;
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else
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return 0;
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}
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#endif
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static void *png_zalloc(void *opaque, unsigned int items, unsigned int size)
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{
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return av_malloc(items * size);
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}
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static void png_zfree(void *opaque, void *ptr)
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{
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av_free(ptr);
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}
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static int png_get_nb_channels(int color_type)
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{
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int channels;
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channels = 1;
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if ((color_type & (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)) ==
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PNG_COLOR_MASK_COLOR)
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channels = 3;
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if (color_type & PNG_COLOR_MASK_ALPHA)
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channels++;
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return channels;
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}
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/* compute the row size of an interleaved pass */
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static int png_pass_row_size(int pass, int bits_per_pixel, int width)
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{
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int shift, xmin, pass_width;
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xmin = png_pass_xmin[pass];
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if (width <= xmin)
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return 0;
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shift = png_pass_xshift[pass];
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pass_width = (width - xmin + (1 << shift) - 1) >> shift;
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return (pass_width * bits_per_pixel + 7) >> 3;
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}
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/* NOTE: we try to construct a good looking image at each pass. width
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is the original image width. We also do pixel format convertion at
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this stage */
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static void png_put_interlaced_row(uint8_t *dst, int width,
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int bits_per_pixel, int pass,
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int color_type, const uint8_t *src)
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{
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int x, mask, dsp_mask, j, src_x, b, bpp;
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uint8_t *d;
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const uint8_t *s;
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mask = png_pass_mask[pass];
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dsp_mask = png_pass_dsp_mask[pass];
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switch(bits_per_pixel) {
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case 1:
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/* we must intialize the line to zero before writing to it */
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if (pass == 0)
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memset(dst, 0, (width + 7) >> 3);
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src_x = 0;
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for(x = 0; x < width; x++) {
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j = (x & 7);
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if ((dsp_mask << j) & 0x80) {
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b = (src[src_x >> 3] >> (7 - (src_x & 7))) & 1;
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dst[x >> 3] |= b << (7 - j);
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}
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if ((mask << j) & 0x80)
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src_x++;
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}
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break;
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default:
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bpp = bits_per_pixel >> 3;
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d = dst;
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s = src;
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if (color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
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for(x = 0; x < width; x++) {
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j = x & 7;
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if ((dsp_mask << j) & 0x80) {
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*(uint32_t *)d = (s[3] << 24) | (s[0] << 16) | (s[1] << 8) | s[2];
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}
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d += bpp;
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if ((mask << j) & 0x80)
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s += bpp;
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}
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} else {
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for(x = 0; x < width; x++) {
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j = x & 7;
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if ((dsp_mask << j) & 0x80) {
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memcpy(d, s, bpp);
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}
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d += bpp;
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if ((mask << j) & 0x80)
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s += bpp;
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}
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}
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break;
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}
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}
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static void png_get_interlaced_row(uint8_t *dst, int row_size,
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int bits_per_pixel, int pass,
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const uint8_t *src, int width)
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{
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int x, mask, dst_x, j, b, bpp;
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uint8_t *d;
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const uint8_t *s;
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mask = png_pass_mask[pass];
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switch(bits_per_pixel) {
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case 1:
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memset(dst, 0, row_size);
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dst_x = 0;
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for(x = 0; x < width; x++) {
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j = (x & 7);
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if ((mask << j) & 0x80) {
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b = (src[x >> 3] >> (7 - j)) & 1;
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dst[dst_x >> 3] |= b << (7 - (dst_x & 7));
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dst_x++;
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}
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}
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break;
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default:
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bpp = bits_per_pixel >> 3;
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d = dst;
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s = src;
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for(x = 0; x < width; x++) {
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j = x & 7;
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if ((mask << j) & 0x80) {
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memcpy(d, s, bpp);
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d += bpp;
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}
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s += bpp;
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}
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break;
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}
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}
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/* XXX: optimize */
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/* NOTE: 'dst' can be equal to 'last' */
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static void png_filter_row(uint8_t *dst, int filter_type,
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uint8_t *src, uint8_t *last, int size, int bpp)
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{
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int i, p;
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switch(filter_type) {
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case PNG_FILTER_VALUE_NONE:
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memcpy(dst, src, size);
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break;
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case PNG_FILTER_VALUE_SUB:
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for(i = 0; i < bpp; i++) {
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dst[i] = src[i];
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}
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for(i = bpp; i < size; i++) {
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p = dst[i - bpp];
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dst[i] = p + src[i];
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}
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break;
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case PNG_FILTER_VALUE_UP:
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for(i = 0; i < size; i++) {
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p = last[i];
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dst[i] = p + src[i];
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}
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break;
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case PNG_FILTER_VALUE_AVG:
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for(i = 0; i < bpp; i++) {
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p = (last[i] >> 1);
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dst[i] = p + src[i];
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}
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for(i = bpp; i < size; i++) {
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p = ((dst[i - bpp] + last[i]) >> 1);
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dst[i] = p + src[i];
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}
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break;
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case PNG_FILTER_VALUE_PAETH:
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for(i = 0; i < bpp; i++) {
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p = last[i];
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dst[i] = p + src[i];
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}
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for(i = bpp; i < size; i++) {
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int a, b, c, pa, pb, pc;
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a = dst[i - bpp];
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b = last[i];
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c = last[i - bpp];
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p = b - c;
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pc = a - c;
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pa = abs(p);
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pb = abs(pc);
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pc = abs(p + pc);
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if (pa <= pb && pa <= pc)
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p = a;
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else if (pb <= pc)
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p = b;
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else
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p = c;
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dst[i] = p + src[i];
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}
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break;
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}
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}
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static void convert_from_rgba32(uint8_t *dst, const uint8_t *src, int width)
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{
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uint8_t *d;
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int j;
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unsigned int v;
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d = dst;
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for(j = 0; j < width; j++) {
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v = ((uint32_t *)src)[j];
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d[0] = v >> 16;
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d[1] = v >> 8;
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d[2] = v;
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d[3] = v >> 24;
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d += 4;
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}
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}
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static void convert_to_rgba32(uint8_t *dst, const uint8_t *src, int width)
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{
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int j;
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unsigned int r, g, b, a;
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for(j = 0;j < width; j++) {
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r = src[0];
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g = src[1];
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b = src[2];
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a = src[3];
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*(uint32_t *)dst = (a << 24) | (r << 16) | (g << 8) | b;
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dst += 4;
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src += 4;
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}
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}
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/* process exactly one decompressed row */
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static void png_handle_row(PNGContext *s)
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{
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uint8_t *ptr, *last_row;
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int got_line;
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if (!s->interlace_type) {
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ptr = s->image_buf + s->image_linesize * s->y;
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/* need to swap bytes correctly for RGB_ALPHA */
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if (s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
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png_filter_row(s->tmp_row, s->crow_buf[0], s->crow_buf + 1,
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s->last_row, s->row_size, s->bpp);
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memcpy(s->last_row, s->tmp_row, s->row_size);
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convert_to_rgba32(ptr, s->tmp_row, s->width);
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} else {
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/* in normal case, we avoid one copy */
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if (s->y == 0)
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last_row = s->last_row;
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else
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last_row = ptr - s->image_linesize;
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png_filter_row(ptr, s->crow_buf[0], s->crow_buf + 1,
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last_row, s->row_size, s->bpp);
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}
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s->y++;
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if (s->y == s->height) {
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s->state |= PNG_ALLIMAGE;
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}
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} else {
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got_line = 0;
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for(;;) {
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ptr = s->image_buf + s->image_linesize * s->y;
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if ((png_pass_ymask[s->pass] << (s->y & 7)) & 0x80) {
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/* if we already read one row, it is time to stop to
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wait for the next one */
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if (got_line)
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break;
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png_filter_row(s->tmp_row, s->crow_buf[0], s->crow_buf + 1,
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s->last_row, s->pass_row_size, s->bpp);
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memcpy(s->last_row, s->tmp_row, s->pass_row_size);
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got_line = 1;
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}
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if ((png_pass_dsp_ymask[s->pass] << (s->y & 7)) & 0x80) {
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/* NOTE: rgba32 is handled directly in png_put_interlaced_row */
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png_put_interlaced_row(ptr, s->width, s->bits_per_pixel, s->pass,
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s->color_type, s->last_row);
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}
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s->y++;
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if (s->y == s->height) {
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for(;;) {
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if (s->pass == NB_PASSES - 1) {
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s->state |= PNG_ALLIMAGE;
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goto the_end;
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} else {
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s->pass++;
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s->y = 0;
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s->pass_row_size = png_pass_row_size(s->pass,
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s->bits_per_pixel,
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s->width);
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s->crow_size = s->pass_row_size + 1;
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if (s->pass_row_size != 0)
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break;
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/* skip pass if empty row */
|
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}
|
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}
|
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}
|
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}
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the_end: ;
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}
|
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}
|
|
|
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static int png_decode_idat(PNGContext *s, int length)
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{
|
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int ret;
|
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s->zstream.avail_in = length;
|
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s->zstream.next_in = s->bytestream;
|
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s->bytestream += length;
|
|
|
|
if(s->bytestream > s->bytestream_end)
|
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return -1;
|
|
|
|
/* decode one line if possible */
|
|
while (s->zstream.avail_in > 0) {
|
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ret = inflate(&s->zstream, Z_PARTIAL_FLUSH);
|
|
if (ret != Z_OK && ret != Z_STREAM_END) {
|
|
return -1;
|
|
}
|
|
if (s->zstream.avail_out == 0) {
|
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if (!(s->state & PNG_ALLIMAGE)) {
|
|
png_handle_row(s);
|
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}
|
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s->zstream.avail_out = s->crow_size;
|
|
s->zstream.next_out = s->crow_buf;
|
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}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int decode_frame(AVCodecContext *avctx,
|
|
void *data, int *data_size,
|
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uint8_t *buf, int buf_size)
|
|
{
|
|
PNGContext * const s = avctx->priv_data;
|
|
AVFrame *picture = data;
|
|
AVFrame * const p= (AVFrame*)&s->picture;
|
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uint32_t tag, length;
|
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int ret, crc;
|
|
|
|
/* special case for last picture */
|
|
if (buf_size == 0) {
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return 0;
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}
|
|
|
|
s->bytestream_start=
|
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s->bytestream= buf;
|
|
s->bytestream_end= buf + buf_size;
|
|
|
|
/* check signature */
|
|
if (memcmp(s->bytestream, pngsig, 8) != 0)
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return -1;
|
|
s->bytestream+= 8;
|
|
s->y=
|
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s->state=0;
|
|
// memset(s, 0, sizeof(PNGContext));
|
|
/* init the zlib */
|
|
s->zstream.zalloc = png_zalloc;
|
|
s->zstream.zfree = png_zfree;
|
|
s->zstream.opaque = NULL;
|
|
ret = inflateInit(&s->zstream);
|
|
if (ret != Z_OK)
|
|
return -1;
|
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for(;;) {
|
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int tag32;
|
|
if (s->bytestream >= s->bytestream_end)
|
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goto fail;
|
|
length = get32(&s->bytestream);
|
|
if (length > 0x7fffffff)
|
|
goto fail;
|
|
tag32 = get32(&s->bytestream);
|
|
tag = bswap_32(tag32);
|
|
#ifdef DEBUG
|
|
printf("png: tag=%c%c%c%c length=%u\n",
|
|
(tag & 0xff),
|
|
((tag >> 8) & 0xff),
|
|
((tag >> 16) & 0xff),
|
|
((tag >> 24) & 0xff), length);
|
|
#endif
|
|
switch(tag) {
|
|
case MKTAG('I', 'H', 'D', 'R'):
|
|
if (length != 13)
|
|
goto fail;
|
|
s->width = get32(&s->bytestream);
|
|
s->height = get32(&s->bytestream);
|
|
s->bit_depth = *s->bytestream++;
|
|
s->color_type = *s->bytestream++;
|
|
s->compression_type = *s->bytestream++;
|
|
s->filter_type = *s->bytestream++;
|
|
s->interlace_type = *s->bytestream++;
|
|
crc = get32(&s->bytestream);
|
|
s->state |= PNG_IHDR;
|
|
#ifdef DEBUG
|
|
printf("width=%d height=%d depth=%d color_type=%d compression_type=%d filter_type=%d interlace_type=%d\n",
|
|
s->width, s->height, s->bit_depth, s->color_type,
|
|
s->compression_type, s->filter_type, s->interlace_type);
|
|
#endif
|
|
break;
|
|
case MKTAG('I', 'D', 'A', 'T'):
|
|
if (!(s->state & PNG_IHDR))
|
|
goto fail;
|
|
if (!(s->state & PNG_IDAT)) {
|
|
/* init image info */
|
|
avctx->width = s->width;
|
|
avctx->height = s->height;
|
|
|
|
s->channels = png_get_nb_channels(s->color_type);
|
|
s->bits_per_pixel = s->bit_depth * s->channels;
|
|
s->bpp = (s->bits_per_pixel + 7) >> 3;
|
|
s->row_size = (avctx->width * s->bits_per_pixel + 7) >> 3;
|
|
|
|
if (s->bit_depth == 8 &&
|
|
s->color_type == PNG_COLOR_TYPE_RGB) {
|
|
avctx->pix_fmt = PIX_FMT_RGB24;
|
|
} else if (s->bit_depth == 8 &&
|
|
s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
|
|
avctx->pix_fmt = PIX_FMT_RGBA32;
|
|
} else if (s->bit_depth == 8 &&
|
|
s->color_type == PNG_COLOR_TYPE_GRAY) {
|
|
avctx->pix_fmt = PIX_FMT_GRAY8;
|
|
} else if (s->bit_depth == 1 &&
|
|
s->color_type == PNG_COLOR_TYPE_GRAY) {
|
|
avctx->pix_fmt = PIX_FMT_MONOBLACK;
|
|
} else if (s->color_type == PNG_COLOR_TYPE_PALETTE) {
|
|
avctx->pix_fmt = PIX_FMT_PAL8;
|
|
} else {
|
|
goto fail;
|
|
}
|
|
if(p->data[0])
|
|
avctx->release_buffer(avctx, p);
|
|
|
|
p->reference= 0;
|
|
if(avctx->get_buffer(avctx, p) < 0){
|
|
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
|
|
goto fail;
|
|
}
|
|
p->pict_type= FF_I_TYPE;
|
|
p->key_frame= 1;
|
|
p->interlaced_frame = !!s->interlace_type;
|
|
|
|
/* compute the compressed row size */
|
|
if (!s->interlace_type) {
|
|
s->crow_size = s->row_size + 1;
|
|
} else {
|
|
s->pass = 0;
|
|
s->pass_row_size = png_pass_row_size(s->pass,
|
|
s->bits_per_pixel,
|
|
s->width);
|
|
s->crow_size = s->pass_row_size + 1;
|
|
}
|
|
#ifdef DEBUG
|
|
printf("row_size=%d crow_size =%d\n",
|
|
s->row_size, s->crow_size);
|
|
#endif
|
|
s->image_buf = p->data[0];
|
|
s->image_linesize = p->linesize[0];
|
|
/* copy the palette if needed */
|
|
if (s->color_type == PNG_COLOR_TYPE_PALETTE)
|
|
memcpy(p->data[1], s->palette, 256 * sizeof(uint32_t));
|
|
/* empty row is used if differencing to the first row */
|
|
s->last_row = av_mallocz(s->row_size);
|
|
if (!s->last_row)
|
|
goto fail;
|
|
if (s->interlace_type ||
|
|
s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
|
|
s->tmp_row = av_malloc(s->row_size);
|
|
if (!s->tmp_row)
|
|
goto fail;
|
|
}
|
|
/* compressed row */
|
|
s->crow_buf = av_malloc(s->row_size + 1);
|
|
if (!s->crow_buf)
|
|
goto fail;
|
|
s->zstream.avail_out = s->crow_size;
|
|
s->zstream.next_out = s->crow_buf;
|
|
}
|
|
s->state |= PNG_IDAT;
|
|
if (png_decode_idat(s, length) < 0)
|
|
goto fail;
|
|
/* skip crc */
|
|
crc = get32(&s->bytestream);
|
|
break;
|
|
case MKTAG('P', 'L', 'T', 'E'):
|
|
{
|
|
int n, i, r, g, b;
|
|
|
|
if ((length % 3) != 0 || length > 256 * 3)
|
|
goto skip_tag;
|
|
/* read the palette */
|
|
n = length / 3;
|
|
for(i=0;i<n;i++) {
|
|
r = *s->bytestream++;
|
|
g = *s->bytestream++;
|
|
b = *s->bytestream++;
|
|
s->palette[i] = (0xff << 24) | (r << 16) | (g << 8) | b;
|
|
}
|
|
for(;i<256;i++) {
|
|
s->palette[i] = (0xff << 24);
|
|
}
|
|
s->state |= PNG_PLTE;
|
|
crc = get32(&s->bytestream);
|
|
}
|
|
break;
|
|
case MKTAG('t', 'R', 'N', 'S'):
|
|
{
|
|
int v, i;
|
|
|
|
/* read the transparency. XXX: Only palette mode supported */
|
|
if (s->color_type != PNG_COLOR_TYPE_PALETTE ||
|
|
length > 256 ||
|
|
!(s->state & PNG_PLTE))
|
|
goto skip_tag;
|
|
for(i=0;i<length;i++) {
|
|
v = *s->bytestream++;
|
|
s->palette[i] = (s->palette[i] & 0x00ffffff) | (v << 24);
|
|
}
|
|
crc = get32(&s->bytestream);
|
|
}
|
|
break;
|
|
case MKTAG('I', 'E', 'N', 'D'):
|
|
if (!(s->state & PNG_ALLIMAGE))
|
|
goto fail;
|
|
crc = get32(&s->bytestream);
|
|
goto exit_loop;
|
|
default:
|
|
/* skip tag */
|
|
skip_tag:
|
|
s->bytestream += length + 4;
|
|
break;
|
|
}
|
|
}
|
|
exit_loop:
|
|
*picture= *(AVFrame*)&s->picture;
|
|
*data_size = sizeof(AVPicture);
|
|
|
|
ret = s->bytestream - s->bytestream_start;
|
|
the_end:
|
|
inflateEnd(&s->zstream);
|
|
av_freep(&s->crow_buf);
|
|
av_freep(&s->last_row);
|
|
av_freep(&s->tmp_row);
|
|
return ret;
|
|
fail:
|
|
ret = -1;
|
|
goto the_end;
|
|
}
|
|
|
|
static void png_write_chunk(uint8_t **f, uint32_t tag,
|
|
const uint8_t *buf, int length)
|
|
{
|
|
uint32_t crc;
|
|
uint8_t tagbuf[4];
|
|
|
|
put32(f, length);
|
|
crc = crc32(0, Z_NULL, 0);
|
|
tagbuf[0] = tag;
|
|
tagbuf[1] = tag >> 8;
|
|
tagbuf[2] = tag >> 16;
|
|
tagbuf[3] = tag >> 24;
|
|
crc = crc32(crc, tagbuf, 4);
|
|
put32(f, bswap_32(tag));
|
|
if (length > 0) {
|
|
crc = crc32(crc, buf, length);
|
|
memcpy(*f, buf, length);
|
|
*f += length;
|
|
}
|
|
put32(f, crc);
|
|
}
|
|
|
|
/* XXX: use avcodec generic function ? */
|
|
static void to_be32(uint8_t *p, uint32_t v)
|
|
{
|
|
p[0] = v >> 24;
|
|
p[1] = v >> 16;
|
|
p[2] = v >> 8;
|
|
p[3] = v;
|
|
}
|
|
|
|
/* XXX: do filtering */
|
|
static int png_write_row(PNGContext *s, const uint8_t *data, int size)
|
|
{
|
|
int ret;
|
|
|
|
s->zstream.avail_in = size;
|
|
s->zstream.next_in = (uint8_t *)data;
|
|
while (s->zstream.avail_in > 0) {
|
|
ret = deflate(&s->zstream, Z_NO_FLUSH);
|
|
if (ret != Z_OK)
|
|
return -1;
|
|
if (s->zstream.avail_out == 0) {
|
|
png_write_chunk(&s->bytestream, MKTAG('I', 'D', 'A', 'T'), s->buf, IOBUF_SIZE);
|
|
s->zstream.avail_out = IOBUF_SIZE;
|
|
s->zstream.next_out = s->buf;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int common_init(AVCodecContext *avctx){
|
|
PNGContext *s = avctx->priv_data;
|
|
|
|
avcodec_get_frame_defaults((AVFrame*)&s->picture);
|
|
avctx->coded_frame= (AVFrame*)&s->picture;
|
|
// s->avctx= avctx;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int encode_frame(AVCodecContext *avctx, unsigned char *buf, int buf_size, void *data){
|
|
PNGContext *s = avctx->priv_data;
|
|
AVFrame *pict = data;
|
|
AVFrame * const p= (AVFrame*)&s->picture;
|
|
int bit_depth, color_type, y, len, row_size, ret, is_progressive;
|
|
int bits_per_pixel, pass_row_size;
|
|
uint8_t *ptr;
|
|
uint8_t *crow_buf = NULL;
|
|
uint8_t *tmp_buf = NULL;
|
|
|
|
*p = *pict;
|
|
p->pict_type= FF_I_TYPE;
|
|
p->key_frame= 1;
|
|
|
|
s->bytestream_start=
|
|
s->bytestream= buf;
|
|
s->bytestream_end= buf+buf_size;
|
|
|
|
is_progressive = !!(avctx->flags & CODEC_FLAG_INTERLACED_DCT);
|
|
switch(avctx->pix_fmt) {
|
|
case PIX_FMT_RGBA32:
|
|
bit_depth = 8;
|
|
color_type = PNG_COLOR_TYPE_RGB_ALPHA;
|
|
break;
|
|
case PIX_FMT_RGB24:
|
|
bit_depth = 8;
|
|
color_type = PNG_COLOR_TYPE_RGB;
|
|
break;
|
|
case PIX_FMT_GRAY8:
|
|
bit_depth = 8;
|
|
color_type = PNG_COLOR_TYPE_GRAY;
|
|
break;
|
|
case PIX_FMT_MONOBLACK:
|
|
bit_depth = 1;
|
|
color_type = PNG_COLOR_TYPE_GRAY;
|
|
break;
|
|
case PIX_FMT_PAL8:
|
|
bit_depth = 8;
|
|
color_type = PNG_COLOR_TYPE_PALETTE;
|
|
break;
|
|
default:
|
|
return -1;
|
|
}
|
|
bits_per_pixel = png_get_nb_channels(color_type) * bit_depth;
|
|
row_size = (avctx->width * bits_per_pixel + 7) >> 3;
|
|
|
|
s->zstream.zalloc = png_zalloc;
|
|
s->zstream.zfree = png_zfree;
|
|
s->zstream.opaque = NULL;
|
|
ret = deflateInit2(&s->zstream, Z_DEFAULT_COMPRESSION,
|
|
Z_DEFLATED, 15, 8, Z_DEFAULT_STRATEGY);
|
|
if (ret != Z_OK)
|
|
return -1;
|
|
crow_buf = av_malloc(row_size + 1);
|
|
if (!crow_buf)
|
|
goto fail;
|
|
if (is_progressive) {
|
|
tmp_buf = av_malloc(row_size + 1);
|
|
if (!tmp_buf)
|
|
goto fail;
|
|
}
|
|
|
|
/* write png header */
|
|
memcpy(s->bytestream, pngsig, 8);
|
|
s->bytestream += 8;
|
|
|
|
to_be32(s->buf, avctx->width);
|
|
to_be32(s->buf + 4, avctx->height);
|
|
s->buf[8] = bit_depth;
|
|
s->buf[9] = color_type;
|
|
s->buf[10] = 0; /* compression type */
|
|
s->buf[11] = 0; /* filter type */
|
|
s->buf[12] = is_progressive; /* interlace type */
|
|
|
|
png_write_chunk(&s->bytestream, MKTAG('I', 'H', 'D', 'R'), s->buf, 13);
|
|
|
|
/* put the palette if needed */
|
|
if (color_type == PNG_COLOR_TYPE_PALETTE) {
|
|
int has_alpha, alpha, i;
|
|
unsigned int v;
|
|
uint32_t *palette;
|
|
uint8_t *alpha_ptr;
|
|
|
|
palette = (uint32_t *)p->data[1];
|
|
ptr = s->buf;
|
|
alpha_ptr = s->buf + 256 * 3;
|
|
has_alpha = 0;
|
|
for(i = 0; i < 256; i++) {
|
|
v = palette[i];
|
|
alpha = v >> 24;
|
|
if (alpha != 0xff)
|
|
has_alpha = 1;
|
|
*alpha_ptr++ = alpha;
|
|
ptr[0] = v >> 16;
|
|
ptr[1] = v >> 8;
|
|
ptr[2] = v;
|
|
ptr += 3;
|
|
}
|
|
png_write_chunk(&s->bytestream, MKTAG('P', 'L', 'T', 'E'), s->buf, 256 * 3);
|
|
if (has_alpha) {
|
|
png_write_chunk(&s->bytestream, MKTAG('t', 'R', 'N', 'S'), s->buf + 256 * 3, 256);
|
|
}
|
|
}
|
|
|
|
/* now put each row */
|
|
s->zstream.avail_out = IOBUF_SIZE;
|
|
s->zstream.next_out = s->buf;
|
|
if (is_progressive) {
|
|
uint8_t *ptr1;
|
|
int pass;
|
|
|
|
for(pass = 0; pass < NB_PASSES; pass++) {
|
|
/* NOTE: a pass is completely omited if no pixels would be
|
|
output */
|
|
pass_row_size = png_pass_row_size(pass, bits_per_pixel, avctx->width);
|
|
if (pass_row_size > 0) {
|
|
for(y = 0; y < avctx->height; y++) {
|
|
if ((png_pass_ymask[pass] << (y & 7)) & 0x80) {
|
|
ptr = p->data[0] + y * p->linesize[0];
|
|
if (color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
|
|
convert_from_rgba32(tmp_buf, ptr, avctx->width);
|
|
ptr1 = tmp_buf;
|
|
} else {
|
|
ptr1 = ptr;
|
|
}
|
|
png_get_interlaced_row(crow_buf + 1, pass_row_size,
|
|
bits_per_pixel, pass,
|
|
ptr1, avctx->width);
|
|
crow_buf[0] = PNG_FILTER_VALUE_NONE;
|
|
png_write_row(s, crow_buf, pass_row_size + 1);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
} else {
|
|
for(y = 0; y < avctx->height; y++) {
|
|
ptr = p->data[0] + y * p->linesize[0];
|
|
if (color_type == PNG_COLOR_TYPE_RGB_ALPHA)
|
|
convert_from_rgba32(crow_buf + 1, ptr, avctx->width);
|
|
else
|
|
memcpy(crow_buf + 1, ptr, row_size);
|
|
crow_buf[0] = PNG_FILTER_VALUE_NONE;
|
|
png_write_row(s, crow_buf, row_size + 1);
|
|
}
|
|
}
|
|
/* compress last bytes */
|
|
for(;;) {
|
|
ret = deflate(&s->zstream, Z_FINISH);
|
|
if (ret == Z_OK || ret == Z_STREAM_END) {
|
|
len = IOBUF_SIZE - s->zstream.avail_out;
|
|
if (len > 0) {
|
|
png_write_chunk(&s->bytestream, MKTAG('I', 'D', 'A', 'T'), s->buf, len);
|
|
}
|
|
s->zstream.avail_out = IOBUF_SIZE;
|
|
s->zstream.next_out = s->buf;
|
|
if (ret == Z_STREAM_END)
|
|
break;
|
|
} else {
|
|
goto fail;
|
|
}
|
|
}
|
|
png_write_chunk(&s->bytestream, MKTAG('I', 'E', 'N', 'D'), NULL, 0);
|
|
|
|
ret = s->bytestream - s->bytestream_start;
|
|
the_end:
|
|
av_free(crow_buf);
|
|
av_free(tmp_buf);
|
|
deflateEnd(&s->zstream);
|
|
return ret;
|
|
fail:
|
|
ret = -1;
|
|
goto the_end;
|
|
}
|
|
|
|
AVCodec png_decoder = {
|
|
"png",
|
|
CODEC_TYPE_VIDEO,
|
|
CODEC_ID_PNG,
|
|
sizeof(PNGContext),
|
|
common_init,
|
|
NULL,
|
|
NULL, //decode_end,
|
|
decode_frame,
|
|
0 /*CODEC_CAP_DR1*/ /*| CODEC_CAP_DRAW_HORIZ_BAND*/,
|
|
NULL
|
|
};
|
|
|
|
AVCodec png_encoder = {
|
|
"png",
|
|
CODEC_TYPE_VIDEO,
|
|
CODEC_ID_PNG,
|
|
sizeof(PNGContext),
|
|
common_init,
|
|
encode_frame,
|
|
NULL, //encode_end,
|
|
.pix_fmts= (enum PixelFormat[]){PIX_FMT_RGB24, PIX_FMT_RGBA32, PIX_FMT_PAL8, PIX_FMT_GRAY8, PIX_FMT_MONOBLACK, -1},
|
|
};
|
|
#endif
|