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677 lines
24 KiB
677 lines
24 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 Libav. |
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* |
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* Libav 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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* Libav 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 Libav; 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 "libavutil/imgutils.h" |
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#include "avcodec.h" |
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#include "bytestream.h" |
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#include "internal.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 2, 4 and 16 bit depth support |
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*/ |
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|
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#include <zlib.h> |
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|
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typedef struct PNGDecContext { |
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PNGDSPContext dsp; |
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|
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GetByteContext gb; |
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AVFrame *prev; |
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|
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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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|
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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 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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|
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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 = ff_png_pass_mask[pass]; |
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dsp_mask = png_pass_dsp_mask[pass]; |
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|
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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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|
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void ff_add_png_paeth_prediction(uint8_t *dst, uint8_t *src, uint8_t *top, |
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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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{ \ |
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r = dst[0]; \ |
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if (bpp >= 2) \ |
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g = dst[1]; \ |
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if (bpp >= 3) \ |
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b = dst[2]; \ |
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if (bpp >= 4) \ |
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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) \ |
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continue; \ |
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dst[i + 1] = g = op(g, src[i + 1], last[i + 1]); \ |
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if (bpp == 2) \ |
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continue; \ |
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dst[i + 2] = b = op(b, src[i + 2], last[i + 2]); \ |
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if (bpp == 3) \ |
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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) { \ |
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UNROLL1(1, op) \ |
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} else if (bpp == 2) { \ |
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UNROLL1(2, op) \ |
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} else if (bpp == 3) { \ |
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UNROLL1(3, op) \ |
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} else if (bpp == 4) { \ |
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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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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 |
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* 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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static av_always_inline void convert_to_rgb32_loco(uint8_t *dst, |
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const uint8_t *src, |
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int width, int loco) |
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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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if (loco) { |
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r = (r + g) & 0xff; |
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b = (b + g) & 0xff; |
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} |
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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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static void convert_to_rgb32(uint8_t *dst, const uint8_t *src, |
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int width, int loco) |
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{ |
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if (loco) |
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convert_to_rgb32_loco(dst, src, width, 1); |
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else |
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convert_to_rgb32_loco(dst, src, width, 0); |
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} |
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static void deloco_rgb24(uint8_t *dst, int size) |
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{ |
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int i; |
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for (i = 0; i < size; i += 3) { |
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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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/* 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->dsp, 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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convert_to_rgb32(ptr, s->tmp_row, s->width, |
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s->filter_type == PNG_FILTER_TYPE_LOCO); |
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FFSWAP(uint8_t *, s->last_row, s->tmp_row); |
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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(&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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} |
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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 && |
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s->color_type == PNG_COLOR_TYPE_RGB && s->y > 0) |
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deloco_rgb24(ptr - s->image_linesize, s->row_size); |
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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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s->color_type == PNG_COLOR_TYPE_RGB) |
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deloco_rgb24(ptr, s->row_size); |
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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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/* 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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|
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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 = 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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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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if (ret == Z_STREAM_END && s->zstream.avail_in > 0) { |
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av_log(NULL, AV_LOG_WARNING, |
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"%d undecompressed bytes left in buffer\n", s->zstream.avail_in); |
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return 0; |
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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 *got_frame, |
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AVPacket *avpkt) |
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{ |
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PNGDecContext *const s = avctx->priv_data; |
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const uint8_t *buf = avpkt->data; |
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int buf_size = avpkt->size; |
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AVFrame *p = data; |
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uint8_t *crow_buf_base = NULL; |
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uint32_t tag, length; |
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int ret; |
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|
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/* check signature */ |
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if (buf_size < 8 || |
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(memcmp(buf, ff_pngsig, 8) != 0 && memcmp(buf, ff_mngsig, 8) != 0)) { |
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av_log(avctx, AV_LOG_ERROR, "Invalid PNG signature (%d).\n", buf_size); |
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return AVERROR_INVALIDDATA; |
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} |
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bytestream2_init(&s->gb, buf + 8, buf_size - 8); |
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s->y = s->state = 0; |
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|
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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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if (bytestream2_get_bytes_left(&s->gb) <= 0) |
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goto fail; |
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length = bytestream2_get_be32(&s->gb); |
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if (length > 0x7fffffff) |
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goto fail; |
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tag = bytestream2_get_le32(&s->gb); |
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ff_dlog(avctx, "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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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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ff_dlog(avctx, "width=%d height=%d depth=%d color_type=%d " |
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"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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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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|
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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 == 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 == 8 && |
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s->color_type == PNG_COLOR_TYPE_RGB_ALPHA) { |
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avctx->pix_fmt = AV_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 = 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 == 1 && |
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s->color_type == PNG_COLOR_TYPE_GRAY) { |
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avctx->pix_fmt = AV_PIX_FMT_MONOBLACK; |
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} else if (s->bit_depth == 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 == 8 && |
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s->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) { |
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avctx->pix_fmt = AV_PIX_FMT_YA8; |
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} else if (s->bit_depth == 16 && |
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s->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) { |
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avctx->pix_fmt = AV_PIX_FMT_YA16BE; |
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} else { |
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goto fail; |
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} |
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|
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if (ff_get_buffer(avctx, p, AV_GET_BUFFER_FLAG_REF) < 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 = AV_PICTURE_TYPE_I; |
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p->key_frame = 1; |
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p->interlaced_frame = !!s->interlace_type; |
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|
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/* compute the compressed row size */ |
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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; |
|
} |
|
ff_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 (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 */ |
|
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)) |
|
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: |
|
/* handle p-frames only if a predecessor frame is available */ |
|
if (s->prev->data[0]) { |
|
if (!(avpkt->flags & AV_PKT_FLAG_KEY)) { |
|
int i, j; |
|
uint8_t *pd = p->data[0]; |
|
uint8_t *pd_last = s->prev->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; |
|
} |
|
} |
|
} |
|
|
|
av_frame_unref(s->prev); |
|
if ((ret = av_frame_ref(s->prev, p)) < 0) |
|
goto fail; |
|
|
|
*got_frame = 1; |
|
|
|
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->prev = av_frame_alloc(); |
|
if (!s->prev) |
|
return AVERROR(ENOMEM); |
|
|
|
ff_pngdsp_init(&s->dsp); |
|
|
|
return 0; |
|
} |
|
|
|
static av_cold int png_dec_end(AVCodecContext *avctx) |
|
{ |
|
PNGDecContext *s = avctx->priv_data; |
|
|
|
av_frame_free(&s->prev); |
|
|
|
return 0; |
|
} |
|
|
|
AVCodec ff_png_decoder = { |
|
.name = "png", |
|
.long_name = NULL_IF_CONFIG_SMALL("PNG (Portable Network Graphics) image"), |
|
.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*/, |
|
};
|
|
|