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757 lines
25 KiB
757 lines
25 KiB
/* |
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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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//#define DEBUG |
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#include "libavutil/imgutils.h" |
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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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#include "pngdsp.h" |
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|
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/* TODO: |
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* - add 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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PNGDSPContext dsp; |
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AVCodecContext *avctx; |
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GetByteContext gb; |
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AVFrame picture1, picture2; |
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AVFrame *current_picture, *last_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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|
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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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0x01, 0x01, 0x11, 0x11, 0x55, 0x55, 0xff, |
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}; |
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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, 0xff, 0x33, 0xff, 0x55, |
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}; |
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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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|
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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 = 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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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] &= 0xFF7F>>j; |
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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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case 2: |
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src_x = 0; |
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for(x = 0; x < width; x++) { |
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int j2 = 2*(x&3); |
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j = (x & 7); |
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if ((dsp_mask << j) & 0x80) { |
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b = (src[src_x >> 2] >> (6 - 2*(src_x & 3))) & 3; |
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dst[x >> 2] &= 0xFF3F>>j2; |
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dst[x >> 2] |= b << (6 - j2); |
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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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case 4: |
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src_x = 0; |
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for(x = 0; x < width; x++) { |
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int j2 = 4*(x&1); |
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j = (x & 7); |
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if ((dsp_mask << j) & 0x80) { |
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b = (src[src_x >> 1] >> (4 - 4*(src_x & 1))) & 15; |
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dst[x >> 1] &= 0xFF0F>>j2; |
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dst[x >> 1] |= b << (4 - j2); |
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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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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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break; |
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} |
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} |
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void ff_add_png_paeth_prediction(uint8_t *dst, uint8_t *src, uint8_t *top, int w, int bpp) |
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{ |
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int i; |
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for(i = 0; i < w; i++) { |
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int a, b, c, p, pa, pb, pc; |
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a = dst[i - bpp]; |
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b = top[i]; |
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c = top[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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} |
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#define UNROLL1(bpp, op) {\ |
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r = dst[0];\ |
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if(bpp >= 2) g = dst[1];\ |
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if(bpp >= 3) b = dst[2];\ |
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if(bpp >= 4) a = dst[3];\ |
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for(; i < size; i+=bpp) {\ |
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dst[i+0] = r = op(r, src[i+0], last[i+0]);\ |
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if(bpp == 1) continue;\ |
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dst[i+1] = g = op(g, src[i+1], last[i+1]);\ |
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if(bpp == 2) continue;\ |
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dst[i+2] = b = op(b, src[i+2], last[i+2]);\ |
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if(bpp == 3) continue;\ |
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dst[i+3] = a = op(a, src[i+3], last[i+3]);\ |
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}\ |
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} |
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#define UNROLL_FILTER(op)\ |
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if(bpp == 1) UNROLL1(1, op)\ |
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else if(bpp == 2) UNROLL1(2, op)\ |
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else if(bpp == 3) UNROLL1(3, op)\ |
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else if(bpp == 4) UNROLL1(4, op)\ |
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else {\ |
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for (; i < size; i += bpp) {\ |
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int j;\ |
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for (j = 0; j < bpp; j++)\ |
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dst[i+j] = op(dst[i+j-bpp], src[i+j], last[i+j]);\ |
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}\ |
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} |
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/* NOTE: 'dst' can be equal to 'last' */ |
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static void png_filter_row(PNGDSPContext *dsp, 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, r, g, b, a; |
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|
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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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if(bpp == 4) { |
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p = *(int*)dst; |
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for(; i < size; i+=bpp) { |
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int s = *(int*)(src+i); |
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p = ((s&0x7f7f7f7f) + (p&0x7f7f7f7f)) ^ ((s^p)&0x80808080); |
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*(int*)(dst+i) = p; |
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} |
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} else { |
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#define OP_SUB(x,s,l) x+s |
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UNROLL_FILTER(OP_SUB); |
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} |
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break; |
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case PNG_FILTER_VALUE_UP: |
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dsp->add_bytes_l2(dst, src, last, size); |
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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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#define OP_AVG(x,s,l) (((x + l) >> 1) + s) & 0xff |
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UNROLL_FILTER(OP_AVG); |
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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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if(bpp > 2 && size > 4) { |
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// would write off the end of the array if we let it process the last pixel with bpp=3 |
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int w = bpp==4 ? size : size-3; |
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dsp->add_paeth_prediction(dst+i, src+i, last+i, w-i, bpp); |
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i = w; |
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} |
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ff_add_png_paeth_prediction(dst+i, src+i, last+i, size-i, bpp); |
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break; |
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} |
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} |
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/* This used to be called "deloco" in FFmpeg |
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* and is actually an inverse reversible colorspace transformation */ |
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#define YUV2RGB(NAME, TYPE) \ |
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static void deloco_ ## NAME(TYPE *dst, int size, int alpha) \ |
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{ \ |
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int i; \ |
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for (i = 0; i < size; i += 3 + alpha) { \ |
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int g = dst [i+1]; \ |
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dst[i+0] += g; \ |
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dst[i+2] += g; \ |
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} \ |
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} |
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YUV2RGB(rgb8, uint8_t) |
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YUV2RGB(rgb16, uint16_t) |
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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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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(&s->dsp, ptr, s->crow_buf[0], s->crow_buf + 1, |
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last_row, s->row_size, s->bpp); |
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/* loco lags by 1 row so that it doesn't interfere with top prediction */ |
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if (s->filter_type == PNG_FILTER_TYPE_LOCO && s->y > 0) { |
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if (s->bit_depth == 16) { |
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deloco_rgb16((uint16_t *)(ptr - s->image_linesize), s->row_size / 2, |
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s->color_type == PNG_COLOR_TYPE_RGB_ALPHA); |
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} else { |
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deloco_rgb8(ptr - s->image_linesize, s->row_size, |
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s->color_type == PNG_COLOR_TYPE_RGB_ALPHA); |
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} |
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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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if (s->filter_type == PNG_FILTER_TYPE_LOCO) { |
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if (s->bit_depth == 16) { |
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deloco_rgb16((uint16_t *)ptr, s->row_size / 2, |
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s->color_type == PNG_COLOR_TYPE_RGB_ALPHA); |
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} else { |
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deloco_rgb8(ptr, s->row_size, |
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s->color_type == PNG_COLOR_TYPE_RGB_ALPHA); |
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} |
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} |
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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->dsp, 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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FFSWAP(uint8_t*, s->last_row, s->tmp_row); |
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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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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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memset(s->last_row, 0, s->row_size); |
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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 = FFMIN(length, bytestream2_get_bytes_left(&s->gb)); |
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s->zstream.next_in = (unsigned char *)s->gb.buffer; |
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bytestream2_skip(&s->gb, length); |
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|
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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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av_log(s->avctx, AV_LOG_ERROR, "inflate returned %d\n", ret); |
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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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AVPacket *avpkt) |
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{ |
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const uint8_t *buf = avpkt->data; |
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int buf_size = avpkt->size; |
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PNGDecContext * const s = avctx->priv_data; |
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AVFrame *picture = data; |
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AVFrame *p; |
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uint8_t *crow_buf_base = NULL; |
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uint32_t tag, length; |
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int64_t sig; |
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int ret; |
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FFSWAP(AVFrame *, s->current_picture, s->last_picture); |
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avctx->coded_frame= s->current_picture; |
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p = s->current_picture; |
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bytestream2_init(&s->gb, buf, buf_size); |
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|
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/* check signature */ |
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sig = bytestream2_get_be64(&s->gb); |
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if (sig != PNGSIG && |
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sig != MNGSIG) { |
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av_log(avctx, AV_LOG_ERROR, "Missing png signature\n"); |
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return -1; |
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} |
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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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av_log(avctx, AV_LOG_ERROR, "inflateInit returned %d\n", ret); |
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return -1; |
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} |
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for(;;) { |
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if (bytestream2_get_bytes_left(&s->gb) <= 0) { |
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av_log(avctx, AV_LOG_ERROR, "No bytes left\n"); |
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goto fail; |
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} |
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|
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length = bytestream2_get_be32(&s->gb); |
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if (length > 0x7fffffff || length > bytestream2_get_bytes_left(&s->gb)) { |
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av_log(avctx, AV_LOG_ERROR, "chunk too big\n"); |
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goto fail; |
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} |
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tag = bytestream2_get_le32(&s->gb); |
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if (avctx->debug & FF_DEBUG_STARTCODE) |
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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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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 = bytestream2_get_be32(&s->gb); |
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s->height = bytestream2_get_be32(&s->gb); |
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if(av_image_check_size(s->width, s->height, 0, avctx)){ |
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s->width= s->height= 0; |
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av_log(avctx, AV_LOG_ERROR, "Invalid image size\n"); |
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goto fail; |
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} |
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s->bit_depth = bytestream2_get_byte(&s->gb); |
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s->color_type = bytestream2_get_byte(&s->gb); |
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s->compression_type = bytestream2_get_byte(&s->gb); |
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s->filter_type = bytestream2_get_byte(&s->gb); |
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s->interlace_type = bytestream2_get_byte(&s->gb); |
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bytestream2_skip(&s->gb, 4); /* crc */ |
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s->state |= PNG_IHDR; |
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if (avctx->debug & FF_DEBUG_PICT_INFO) |
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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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break; |
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case MKTAG('I', 'D', 'A', 'T'): |
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if (!(s->state & PNG_IHDR)) { |
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av_log(avctx, AV_LOG_ERROR, "IDAT without IHDR\n"); |
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goto fail; |
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} |
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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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|
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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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|
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if ((s->bit_depth == 2 || s->bit_depth == 4 || s->bit_depth == 8) && |
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s->color_type == PNG_COLOR_TYPE_RGB) { |
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avctx->pix_fmt = AV_PIX_FMT_RGB24; |
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} else if ((s->bit_depth == 2 || s->bit_depth == 4 || s->bit_depth == 8) && |
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s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) { |
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avctx->pix_fmt = AV_PIX_FMT_RGBA; |
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} else if ((s->bit_depth == 2 || s->bit_depth == 4 || s->bit_depth == 8) && |
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s->color_type == PNG_COLOR_TYPE_GRAY) { |
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avctx->pix_fmt = AV_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 = AV_PIX_FMT_GRAY16BE; |
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} else if (s->bit_depth == 16 && |
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s->color_type == PNG_COLOR_TYPE_RGB) { |
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avctx->pix_fmt = AV_PIX_FMT_RGB48BE; |
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} else if (s->bit_depth == 16 && |
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s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) { |
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avctx->pix_fmt = AV_PIX_FMT_RGBA64BE; |
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} else if ((s->bits_per_pixel == 1 || s->bits_per_pixel == 2 || s->bits_per_pixel == 4 || s->bits_per_pixel == 8) && |
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s->color_type == PNG_COLOR_TYPE_PALETTE) { |
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avctx->pix_fmt = AV_PIX_FMT_PAL8; |
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} else if (s->bit_depth == 1) { |
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avctx->pix_fmt = AV_PIX_FMT_MONOBLACK; |
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} else if (s->bit_depth == 8 && |
|
s->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) { |
|
avctx->pix_fmt = AV_PIX_FMT_Y400A; |
|
} else { |
|
av_log(avctx, AV_LOG_ERROR, "unsupported bit depth %d " |
|
"and color type %d\n", |
|
s->bit_depth, s->color_type); |
|
goto fail; |
|
} |
|
if(p->data[0]) |
|
avctx->release_buffer(avctx, p); |
|
|
|
p->reference= 3; |
|
if(avctx->get_buffer(avctx, p) < 0){ |
|
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); |
|
goto fail; |
|
} |
|
p->pict_type= AV_PICTURE_TYPE_I; |
|
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 = ff_png_pass_row_size(s->pass, |
|
s->bits_per_pixel, |
|
s->width); |
|
s->crow_size = s->pass_row_size + 1; |
|
} |
|
av_dlog(avctx, "row_size=%d crow_size =%d\n", |
|
s->row_size, s->crow_size); |
|
s->image_buf = p->data[0]; |
|
s->image_linesize = p->linesize[0]; |
|
/* copy the palette if needed */ |
|
if (avctx->pix_fmt == AV_PIX_FMT_PAL8) |
|
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 */ |
|
crow_buf_base = av_malloc(s->row_size + 16); |
|
if (!crow_buf_base) |
|
goto fail; |
|
|
|
/* we want crow_buf+1 to be 16-byte aligned */ |
|
s->crow_buf = crow_buf_base + 15; |
|
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; |
|
bytestream2_skip(&s->gb, 4); /* crc */ |
|
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 = bytestream2_get_byte(&s->gb); |
|
g = bytestream2_get_byte(&s->gb); |
|
b = bytestream2_get_byte(&s->gb); |
|
s->palette[i] = (0xff << 24) | (r << 16) | (g << 8) | b; |
|
} |
|
for(;i<256;i++) { |
|
s->palette[i] = (0xff << 24); |
|
} |
|
s->state |= PNG_PLTE; |
|
bytestream2_skip(&s->gb, 4); /* crc */ |
|
} |
|
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 = bytestream2_get_byte(&s->gb); |
|
s->palette[i] = (s->palette[i] & 0x00ffffff) | (v << 24); |
|
} |
|
bytestream2_skip(&s->gb, 4); /* crc */ |
|
} |
|
break; |
|
case MKTAG('I', 'E', 'N', 'D'): |
|
if (!(s->state & PNG_ALLIMAGE)) |
|
av_log(avctx, AV_LOG_ERROR, "IEND without all image\n"); |
|
if (!(s->state & (PNG_ALLIMAGE|PNG_IDAT))) { |
|
goto fail; |
|
} |
|
bytestream2_skip(&s->gb, 4); /* crc */ |
|
goto exit_loop; |
|
default: |
|
/* skip tag */ |
|
skip_tag: |
|
bytestream2_skip(&s->gb, length + 4); |
|
break; |
|
} |
|
} |
|
exit_loop: |
|
|
|
if(s->bits_per_pixel == 1 && s->color_type == PNG_COLOR_TYPE_PALETTE){ |
|
int i, j; |
|
uint8_t *pd = s->current_picture->data[0]; |
|
for(j=0; j < s->height; j++) { |
|
for(i=s->width/8-1; i>=0; i--) { |
|
pd[8*i+7]= pd[i] &1; |
|
pd[8*i+6]= (pd[i]>>1)&1; |
|
pd[8*i+5]= (pd[i]>>2)&1; |
|
pd[8*i+4]= (pd[i]>>3)&1; |
|
pd[8*i+3]= (pd[i]>>4)&1; |
|
pd[8*i+2]= (pd[i]>>5)&1; |
|
pd[8*i+1]= (pd[i]>>6)&1; |
|
pd[8*i+0]= pd[i]>>7; |
|
} |
|
pd += s->image_linesize; |
|
} |
|
} |
|
if(s->bits_per_pixel == 2){ |
|
int i, j; |
|
uint8_t *pd = s->current_picture->data[0]; |
|
for(j=0; j < s->height; j++) { |
|
if (s->color_type == PNG_COLOR_TYPE_PALETTE){ |
|
for(i=s->width/4-1; i>=0; i--) { |
|
pd[4*i+3]= pd[i] &3; |
|
pd[4*i+2]= (pd[i]>>2)&3; |
|
pd[4*i+1]= (pd[i]>>4)&3; |
|
pd[4*i+0]= pd[i]>>6; |
|
} |
|
} else { |
|
for(i=s->width/4-1; i>=0; i--) { |
|
pd[4*i+3]= ( pd[i] &3)*0x55; |
|
pd[4*i+2]= ((pd[i]>>2)&3)*0x55; |
|
pd[4*i+1]= ((pd[i]>>4)&3)*0x55; |
|
pd[4*i+0]= ( pd[i]>>6 )*0x55; |
|
} |
|
} |
|
pd += s->image_linesize; |
|
} |
|
} |
|
if(s->bits_per_pixel == 4){ |
|
int i, j; |
|
uint8_t *pd = s->current_picture->data[0]; |
|
for(j=0; j < s->height; j++) { |
|
if (s->color_type == PNG_COLOR_TYPE_PALETTE){ |
|
for(i=s->width/2-1; i>=0; i--) { |
|
pd[2*i+1]= pd[i]&15; |
|
pd[2*i+0]= pd[i]>>4; |
|
} |
|
} else { |
|
for(i=s->width/2-1; i>=0; i--) { |
|
pd[2*i+1]= (pd[i]&15)*0x11; |
|
pd[2*i+0]= (pd[i]>>4)*0x11; |
|
} |
|
} |
|
pd += s->image_linesize; |
|
} |
|
} |
|
|
|
/* handle p-frames only if a predecessor frame is available */ |
|
if(s->last_picture->data[0] != NULL) { |
|
if( !(avpkt->flags & AV_PKT_FLAG_KEY) |
|
&& s->last_picture->width == s->current_picture->width |
|
&& s->last_picture->height== s->current_picture->height |
|
) { |
|
int i, j; |
|
uint8_t *pd = s->current_picture->data[0]; |
|
uint8_t *pd_last = s->last_picture->data[0]; |
|
|
|
for(j=0; j < s->height; j++) { |
|
for(i=0; i < s->width * s->bpp; i++) { |
|
pd[i] += pd_last[i]; |
|
} |
|
pd += s->image_linesize; |
|
pd_last += s->image_linesize; |
|
} |
|
} |
|
} |
|
|
|
*picture= *s->current_picture; |
|
*data_size = sizeof(AVFrame); |
|
|
|
ret = bytestream2_tell(&s->gb); |
|
the_end: |
|
inflateEnd(&s->zstream); |
|
av_free(crow_buf_base); |
|
s->crow_buf = NULL; |
|
av_freep(&s->last_row); |
|
av_freep(&s->tmp_row); |
|
return ret; |
|
fail: |
|
ret = -1; |
|
goto the_end; |
|
} |
|
|
|
static av_cold int png_dec_init(AVCodecContext *avctx) |
|
{ |
|
PNGDecContext *s = avctx->priv_data; |
|
|
|
s->current_picture = &s->picture1; |
|
s->last_picture = &s->picture2; |
|
avcodec_get_frame_defaults(&s->picture1); |
|
avcodec_get_frame_defaults(&s->picture2); |
|
|
|
ff_pngdsp_init(&s->dsp); |
|
|
|
s->avctx = avctx; |
|
|
|
return 0; |
|
} |
|
|
|
static av_cold int png_dec_end(AVCodecContext *avctx) |
|
{ |
|
PNGDecContext *s = avctx->priv_data; |
|
|
|
if (s->picture1.data[0]) |
|
avctx->release_buffer(avctx, &s->picture1); |
|
if (s->picture2.data[0]) |
|
avctx->release_buffer(avctx, &s->picture2); |
|
|
|
return 0; |
|
} |
|
|
|
AVCodec ff_png_decoder = { |
|
.name = "png", |
|
.type = AVMEDIA_TYPE_VIDEO, |
|
.id = AV_CODEC_ID_PNG, |
|
.priv_data_size = sizeof(PNGDecContext), |
|
.init = png_dec_init, |
|
.close = png_dec_end, |
|
.decode = decode_frame, |
|
.capabilities = CODEC_CAP_DR1 /*| CODEC_CAP_DRAW_HORIZ_BAND*/, |
|
.long_name = NULL_IF_CONFIG_SMALL("PNG (Portable Network Graphics) image"), |
|
};
|
|
|