553 lines
18 KiB
C
553 lines
18 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 file is part of FFmpeg.
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*
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* FFmpeg 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 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg 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 FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "avcodec.h"
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#include "bytestream.h"
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#include "png.h"
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/* TODO:
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* - add 2, 4 and 16 bit depth support
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*/
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#include <zlib.h>
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//#define DEBUG
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typedef struct PNGDecContext {
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const uint8_t *bytestream;
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const uint8_t *bytestream_start;
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const 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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} PNGDecContext;
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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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/* 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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/* 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 conversion 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 = ff_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 initialize 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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/* 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_to_rgb32(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(PNGDecContext *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_rgb32(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 ((ff_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: RGB32 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 = ff_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(PNGDecContext *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;
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if(s->bytestream > s->bytestream_end)
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return -1;
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/* decode one line if possible */
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while (s->zstream.avail_in > 0) {
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ret = inflate(&s->zstream, Z_PARTIAL_FLUSH);
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if (ret != Z_OK && ret != Z_STREAM_END) {
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return -1;
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}
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if (s->zstream.avail_out == 0) {
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if (!(s->state & PNG_ALLIMAGE)) {
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png_handle_row(s);
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}
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s->zstream.avail_out = s->crow_size;
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s->zstream.next_out = s->crow_buf;
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}
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}
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return 0;
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}
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static int decode_frame(AVCodecContext *avctx,
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void *data, int *data_size,
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const uint8_t *buf, int buf_size)
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{
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PNGDecContext * const s = avctx->priv_data;
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AVFrame *picture = data;
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AVFrame * const p= (AVFrame*)&s->picture;
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uint32_t tag, length;
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int ret, crc;
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s->bytestream_start=
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s->bytestream= buf;
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s->bytestream_end= buf + buf_size;
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/* check signature */
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if (memcmp(s->bytestream, ff_pngsig, 8) != 0)
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return -1;
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s->bytestream+= 8;
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s->y=
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s->state=0;
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// memset(s, 0, sizeof(PNGDecContext));
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/* init the zlib */
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s->zstream.zalloc = ff_png_zalloc;
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s->zstream.zfree = ff_png_zfree;
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s->zstream.opaque = NULL;
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ret = inflateInit(&s->zstream);
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if (ret != Z_OK)
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return -1;
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for(;;) {
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int tag32;
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if (s->bytestream >= s->bytestream_end)
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goto fail;
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length = bytestream_get_be32(&s->bytestream);
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if (length > 0x7fffffff)
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goto fail;
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tag32 = bytestream_get_be32(&s->bytestream);
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tag = bswap_32(tag32);
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#ifdef DEBUG
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av_log(avctx, AV_LOG_DEBUG, "png: tag=%c%c%c%c length=%u\n",
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(tag & 0xff),
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((tag >> 8) & 0xff),
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((tag >> 16) & 0xff),
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((tag >> 24) & 0xff), length);
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#endif
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switch(tag) {
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case MKTAG('I', 'H', 'D', 'R'):
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if (length != 13)
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goto fail;
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s->width = bytestream_get_be32(&s->bytestream);
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s->height = bytestream_get_be32(&s->bytestream);
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if(avcodec_check_dimensions(avctx, s->width, s->height)){
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s->width= s->height= 0;
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goto fail;
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}
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s->bit_depth = *s->bytestream++;
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s->color_type = *s->bytestream++;
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s->compression_type = *s->bytestream++;
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s->filter_type = *s->bytestream++;
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s->interlace_type = *s->bytestream++;
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crc = bytestream_get_be32(&s->bytestream);
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s->state |= PNG_IHDR;
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#ifdef DEBUG
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av_log(avctx, AV_LOG_DEBUG, "width=%d height=%d depth=%d color_type=%d compression_type=%d filter_type=%d interlace_type=%d\n",
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s->width, s->height, s->bit_depth, s->color_type,
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s->compression_type, s->filter_type, s->interlace_type);
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#endif
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break;
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case MKTAG('I', 'D', 'A', 'T'):
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if (!(s->state & PNG_IHDR))
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goto fail;
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if (!(s->state & PNG_IDAT)) {
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/* init image info */
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avctx->width = s->width;
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avctx->height = s->height;
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s->channels = ff_png_get_nb_channels(s->color_type);
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s->bits_per_pixel = s->bit_depth * s->channels;
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s->bpp = (s->bits_per_pixel + 7) >> 3;
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s->row_size = (avctx->width * s->bits_per_pixel + 7) >> 3;
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if (s->bit_depth == 8 &&
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s->color_type == PNG_COLOR_TYPE_RGB) {
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avctx->pix_fmt = PIX_FMT_RGB24;
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} else if (s->bit_depth == 8 &&
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s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
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avctx->pix_fmt = PIX_FMT_RGB32;
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} else if (s->bit_depth == 8 &&
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s->color_type == PNG_COLOR_TYPE_GRAY) {
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avctx->pix_fmt = PIX_FMT_GRAY8;
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} else if (s->bit_depth == 16 &&
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s->color_type == PNG_COLOR_TYPE_GRAY) {
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avctx->pix_fmt = PIX_FMT_GRAY16BE;
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} else if (s->bit_depth == 1 &&
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s->color_type == PNG_COLOR_TYPE_GRAY) {
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avctx->pix_fmt = PIX_FMT_MONOBLACK;
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} else if (s->color_type == PNG_COLOR_TYPE_PALETTE) {
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avctx->pix_fmt = PIX_FMT_PAL8;
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} else {
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goto fail;
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}
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if(p->data[0])
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avctx->release_buffer(avctx, p);
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p->reference= 0;
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if(avctx->get_buffer(avctx, p) < 0){
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av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
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goto fail;
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}
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p->pict_type= FF_I_TYPE;
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p->key_frame= 1;
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p->interlaced_frame = !!s->interlace_type;
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/* compute the compressed row size */
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if (!s->interlace_type) {
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s->crow_size = s->row_size + 1;
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} else {
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s->pass = 0;
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s->pass_row_size = ff_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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}
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#ifdef DEBUG
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av_log(avctx, AV_LOG_DEBUG, "row_size=%d crow_size =%d\n",
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s->row_size, s->crow_size);
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#endif
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s->image_buf = p->data[0];
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s->image_linesize = p->linesize[0];
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/* copy the palette if needed */
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if (s->color_type == PNG_COLOR_TYPE_PALETTE)
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memcpy(p->data[1], s->palette, 256 * sizeof(uint32_t));
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/* empty row is used if differencing to the first row */
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s->last_row = av_mallocz(s->row_size);
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if (!s->last_row)
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goto fail;
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if (s->interlace_type ||
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s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
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s->tmp_row = av_malloc(s->row_size);
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if (!s->tmp_row)
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goto fail;
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}
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/* compressed row */
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s->crow_buf = av_malloc(s->row_size + 1);
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if (!s->crow_buf)
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goto fail;
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s->zstream.avail_out = s->crow_size;
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s->zstream.next_out = s->crow_buf;
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}
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s->state |= PNG_IDAT;
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if (png_decode_idat(s, length) < 0)
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goto fail;
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/* skip crc */
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crc = bytestream_get_be32(&s->bytestream);
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break;
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case MKTAG('P', 'L', 'T', 'E'):
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{
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int n, i, r, g, b;
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if ((length % 3) != 0 || length > 256 * 3)
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goto skip_tag;
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/* read the palette */
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n = length / 3;
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for(i=0;i<n;i++) {
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r = *s->bytestream++;
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g = *s->bytestream++;
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b = *s->bytestream++;
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s->palette[i] = (0xff << 24) | (r << 16) | (g << 8) | b;
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}
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for(;i<256;i++) {
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s->palette[i] = (0xff << 24);
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}
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s->state |= PNG_PLTE;
|
|
crc = bytestream_get_be32(&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 = bytestream_get_be32(&s->bytestream);
|
|
}
|
|
break;
|
|
case MKTAG('I', 'E', 'N', 'D'):
|
|
if (!(s->state & PNG_ALLIMAGE))
|
|
goto fail;
|
|
crc = bytestream_get_be32(&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 int png_dec_init(AVCodecContext *avctx){
|
|
PNGDecContext *s = avctx->priv_data;
|
|
|
|
avcodec_get_frame_defaults((AVFrame*)&s->picture);
|
|
avctx->coded_frame= (AVFrame*)&s->picture;
|
|
|
|
return 0;
|
|
}
|
|
|
|
AVCodec png_decoder = {
|
|
"png",
|
|
CODEC_TYPE_VIDEO,
|
|
CODEC_ID_PNG,
|
|
sizeof(PNGDecContext),
|
|
png_dec_init,
|
|
NULL,
|
|
NULL, //decode_end,
|
|
decode_frame,
|
|
0 /*CODEC_CAP_DR1*/ /*| CODEC_CAP_DRAW_HORIZ_BAND*/,
|
|
NULL
|
|
};
|