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pngdec.c
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1 /*
2  * PNG image format
3  * Copyright (c) 2003 Fabrice Bellard
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 //#define DEBUG
23 
24 #include "libavutil/bprint.h"
25 #include "libavutil/imgutils.h"
26 #include "avcodec.h"
27 #include "bytestream.h"
28 #include "internal.h"
29 #include "png.h"
30 #include "pngdsp.h"
31 #include "thread.h"
32 
33 #include <zlib.h>
34 
35 typedef struct PNGDecContext {
38 
42 
43  int state;
44  int width, height;
45  int bit_depth;
50  int channels;
52  int bpp;
53 
56  uint32_t palette[256];
59  unsigned int last_row_size;
61  unsigned int tmp_row_size;
64  int pass;
65  int crow_size; /* compressed row size (include filter type) */
66  int row_size; /* decompressed row size */
67  int pass_row_size; /* decompress row size of the current pass */
68  int y;
69  z_stream zstream;
71 
72 /* Mask to determine which pixels are valid in a pass */
73 static const uint8_t png_pass_mask[NB_PASSES] = {
74  0x01, 0x01, 0x11, 0x11, 0x55, 0x55, 0xff,
75 };
76 
77 /* Mask to determine which y pixels can be written in a pass */
79  0xff, 0xff, 0x0f, 0xff, 0x33, 0xff, 0x55,
80 };
81 
82 /* Mask to determine which pixels to overwrite while displaying */
84  0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff
85 };
86 
87 /* NOTE: we try to construct a good looking image at each pass. width
88  * is the original image width. We also do pixel format conversion at
89  * this stage */
90 static void png_put_interlaced_row(uint8_t *dst, int width,
91  int bits_per_pixel, int pass,
92  int color_type, const uint8_t *src)
93 {
94  int x, mask, dsp_mask, j, src_x, b, bpp;
95  uint8_t *d;
96  const uint8_t *s;
97 
98  mask = png_pass_mask[pass];
99  dsp_mask = png_pass_dsp_mask[pass];
100 
101  switch (bits_per_pixel) {
102  case 1:
103  src_x = 0;
104  for (x = 0; x < width; x++) {
105  j = (x & 7);
106  if ((dsp_mask << j) & 0x80) {
107  b = (src[src_x >> 3] >> (7 - (src_x & 7))) & 1;
108  dst[x >> 3] &= 0xFF7F>>j;
109  dst[x >> 3] |= b << (7 - j);
110  }
111  if ((mask << j) & 0x80)
112  src_x++;
113  }
114  break;
115  case 2:
116  src_x = 0;
117  for (x = 0; x < width; x++) {
118  int j2 = 2 * (x & 3);
119  j = (x & 7);
120  if ((dsp_mask << j) & 0x80) {
121  b = (src[src_x >> 2] >> (6 - 2*(src_x & 3))) & 3;
122  dst[x >> 2] &= 0xFF3F>>j2;
123  dst[x >> 2] |= b << (6 - j2);
124  }
125  if ((mask << j) & 0x80)
126  src_x++;
127  }
128  break;
129  case 4:
130  src_x = 0;
131  for (x = 0; x < width; x++) {
132  int j2 = 4*(x&1);
133  j = (x & 7);
134  if ((dsp_mask << j) & 0x80) {
135  b = (src[src_x >> 1] >> (4 - 4*(src_x & 1))) & 15;
136  dst[x >> 1] &= 0xFF0F>>j2;
137  dst[x >> 1] |= b << (4 - j2);
138  }
139  if ((mask << j) & 0x80)
140  src_x++;
141  }
142  break;
143  default:
144  bpp = bits_per_pixel >> 3;
145  d = dst;
146  s = src;
147  for (x = 0; x < width; x++) {
148  j = x & 7;
149  if ((dsp_mask << j) & 0x80) {
150  memcpy(d, s, bpp);
151  }
152  d += bpp;
153  if ((mask << j) & 0x80)
154  s += bpp;
155  }
156  break;
157  }
158 }
159 
161  int w, int bpp)
162 {
163  int i;
164  for (i = 0; i < w; i++) {
165  int a, b, c, p, pa, pb, pc;
166 
167  a = dst[i - bpp];
168  b = top[i];
169  c = top[i - bpp];
170 
171  p = b - c;
172  pc = a - c;
173 
174  pa = abs(p);
175  pb = abs(pc);
176  pc = abs(p + pc);
177 
178  if (pa <= pb && pa <= pc)
179  p = a;
180  else if (pb <= pc)
181  p = b;
182  else
183  p = c;
184  dst[i] = p + src[i];
185  }
186 }
187 
188 #define UNROLL1(bpp, op) \
189  { \
190  r = dst[0]; \
191  if (bpp >= 2) \
192  g = dst[1]; \
193  if (bpp >= 3) \
194  b = dst[2]; \
195  if (bpp >= 4) \
196  a = dst[3]; \
197  for (; i <= size - bpp; i += bpp) { \
198  dst[i + 0] = r = op(r, src[i + 0], last[i + 0]); \
199  if (bpp == 1) \
200  continue; \
201  dst[i + 1] = g = op(g, src[i + 1], last[i + 1]); \
202  if (bpp == 2) \
203  continue; \
204  dst[i + 2] = b = op(b, src[i + 2], last[i + 2]); \
205  if (bpp == 3) \
206  continue; \
207  dst[i + 3] = a = op(a, src[i + 3], last[i + 3]); \
208  } \
209  }
210 
211 #define UNROLL_FILTER(op) \
212  if (bpp == 1) { \
213  UNROLL1(1, op) \
214  } else if (bpp == 2) { \
215  UNROLL1(2, op) \
216  } else if (bpp == 3) { \
217  UNROLL1(3, op) \
218  } else if (bpp == 4) { \
219  UNROLL1(4, op) \
220  } \
221  for (; i < size; i++) { \
222  dst[i] = op(dst[i - bpp], src[i], last[i]); \
223  }
224 
225 /* NOTE: 'dst' can be equal to 'last' */
226 static void png_filter_row(PNGDSPContext *dsp, uint8_t *dst, int filter_type,
227  uint8_t *src, uint8_t *last, int size, int bpp)
228 {
229  int i, p, r, g, b, a;
230 
231  switch (filter_type) {
233  memcpy(dst, src, size);
234  break;
236  for (i = 0; i < bpp; i++)
237  dst[i] = src[i];
238  if (bpp == 4) {
239  p = *(int *)dst;
240  for (; i < size; i += bpp) {
241  unsigned s = *(int *)(src + i);
242  p = ((s & 0x7f7f7f7f) + (p & 0x7f7f7f7f)) ^ ((s ^ p) & 0x80808080);
243  *(int *)(dst + i) = p;
244  }
245  } else {
246 #define OP_SUB(x, s, l) ((x) + (s))
248  }
249  break;
250  case PNG_FILTER_VALUE_UP:
251  dsp->add_bytes_l2(dst, src, last, size);
252  break;
254  for (i = 0; i < bpp; i++) {
255  p = (last[i] >> 1);
256  dst[i] = p + src[i];
257  }
258 #define OP_AVG(x, s, l) (((((x) + (l)) >> 1) + (s)) & 0xff)
260  break;
262  for (i = 0; i < bpp; i++) {
263  p = last[i];
264  dst[i] = p + src[i];
265  }
266  if (bpp > 2 && size > 4) {
267  /* would write off the end of the array if we let it process
268  * the last pixel with bpp=3 */
269  int w = bpp == 4 ? size : size - 3;
270  dsp->add_paeth_prediction(dst + i, src + i, last + i, w - i, bpp);
271  i = w;
272  }
273  ff_add_png_paeth_prediction(dst + i, src + i, last + i, size - i, bpp);
274  break;
275  }
276 }
277 
278 /* This used to be called "deloco" in FFmpeg
279  * and is actually an inverse reversible colorspace transformation */
280 #define YUV2RGB(NAME, TYPE) \
281 static void deloco_ ## NAME(TYPE *dst, int size, int alpha) \
282 { \
283  int i; \
284  for (i = 0; i < size; i += 3 + alpha) { \
285  int g = dst [i + 1]; \
286  dst[i + 0] += g; \
287  dst[i + 2] += g; \
288  } \
289 }
290 
291 YUV2RGB(rgb8, uint8_t)
292 YUV2RGB(rgb16, uint16_t)
293 
294 /* process exactly one decompressed row */
296 {
297  uint8_t *ptr, *last_row;
298  int got_line;
299 
300  if (!s->interlace_type) {
301  ptr = s->image_buf + s->image_linesize * s->y;
302  if (s->y == 0)
303  last_row = s->last_row;
304  else
305  last_row = ptr - s->image_linesize;
306 
307  png_filter_row(&s->dsp, ptr, s->crow_buf[0], s->crow_buf + 1,
308  last_row, s->row_size, s->bpp);
309  /* loco lags by 1 row so that it doesn't interfere with top prediction */
310  if (s->filter_type == PNG_FILTER_TYPE_LOCO && s->y > 0) {
311  if (s->bit_depth == 16) {
312  deloco_rgb16((uint16_t *)(ptr - s->image_linesize), s->row_size / 2,
313  s->color_type == PNG_COLOR_TYPE_RGB_ALPHA);
314  } else {
315  deloco_rgb8(ptr - s->image_linesize, s->row_size,
316  s->color_type == PNG_COLOR_TYPE_RGB_ALPHA);
317  }
318  }
319  s->y++;
320  if (s->y == s->height) {
321  s->state |= PNG_ALLIMAGE;
322  if (s->filter_type == PNG_FILTER_TYPE_LOCO) {
323  if (s->bit_depth == 16) {
324  deloco_rgb16((uint16_t *)ptr, s->row_size / 2,
325  s->color_type == PNG_COLOR_TYPE_RGB_ALPHA);
326  } else {
327  deloco_rgb8(ptr, s->row_size,
328  s->color_type == PNG_COLOR_TYPE_RGB_ALPHA);
329  }
330  }
331  }
332  } else {
333  got_line = 0;
334  for (;;) {
335  ptr = s->image_buf + s->image_linesize * s->y;
336  if ((ff_png_pass_ymask[s->pass] << (s->y & 7)) & 0x80) {
337  /* if we already read one row, it is time to stop to
338  * wait for the next one */
339  if (got_line)
340  break;
341  png_filter_row(&s->dsp, s->tmp_row, s->crow_buf[0], s->crow_buf + 1,
342  s->last_row, s->pass_row_size, s->bpp);
343  FFSWAP(uint8_t *, s->last_row, s->tmp_row);
344  FFSWAP(unsigned int, s->last_row_size, s->tmp_row_size);
345  got_line = 1;
346  }
347  if ((png_pass_dsp_ymask[s->pass] << (s->y & 7)) & 0x80) {
348  png_put_interlaced_row(ptr, s->width, s->bits_per_pixel, s->pass,
349  s->color_type, s->last_row);
350  }
351  s->y++;
352  if (s->y == s->height) {
353  memset(s->last_row, 0, s->row_size);
354  for (;;) {
355  if (s->pass == NB_PASSES - 1) {
356  s->state |= PNG_ALLIMAGE;
357  goto the_end;
358  } else {
359  s->pass++;
360  s->y = 0;
361  s->pass_row_size = ff_png_pass_row_size(s->pass,
362  s->bits_per_pixel,
363  s->width);
364  s->crow_size = s->pass_row_size + 1;
365  if (s->pass_row_size != 0)
366  break;
367  /* skip pass if empty row */
368  }
369  }
370  }
371  }
372 the_end:;
373  }
374 }
375 
377 {
378  int ret;
379  s->zstream.avail_in = FFMIN(length, bytestream2_get_bytes_left(&s->gb));
380  s->zstream.next_in = (unsigned char *)s->gb.buffer;
381  bytestream2_skip(&s->gb, length);
382 
383  /* decode one line if possible */
384  while (s->zstream.avail_in > 0) {
385  ret = inflate(&s->zstream, Z_PARTIAL_FLUSH);
386  if (ret != Z_OK && ret != Z_STREAM_END) {
387  av_log(s->avctx, AV_LOG_ERROR, "inflate returned error %d\n", ret);
388  return AVERROR_EXTERNAL;
389  }
390  if (s->zstream.avail_out == 0) {
391  if (!(s->state & PNG_ALLIMAGE)) {
392  png_handle_row(s);
393  }
394  s->zstream.avail_out = s->crow_size;
395  s->zstream.next_out = s->crow_buf;
396  }
397  if (ret == Z_STREAM_END && s->zstream.avail_in > 0) {
398  av_log(NULL, AV_LOG_WARNING,
399  "%d undecompressed bytes left in buffer\n", s->zstream.avail_in);
400  return 0;
401  }
402  }
403  return 0;
404 }
405 
406 static int decode_zbuf(AVBPrint *bp, const uint8_t *data,
407  const uint8_t *data_end)
408 {
409  z_stream zstream;
410  unsigned char *buf;
411  unsigned buf_size;
412  int ret;
413 
414  zstream.zalloc = ff_png_zalloc;
415  zstream.zfree = ff_png_zfree;
416  zstream.opaque = NULL;
417  if (inflateInit(&zstream) != Z_OK)
418  return AVERROR_EXTERNAL;
419  zstream.next_in = (unsigned char *)data;
420  zstream.avail_in = data_end - data;
421  av_bprint_init(bp, 0, -1);
422 
423  while (zstream.avail_in > 0) {
424  av_bprint_get_buffer(bp, 1, &buf, &buf_size);
425  if (!buf_size) {
426  ret = AVERROR(ENOMEM);
427  goto fail;
428  }
429  zstream.next_out = buf;
430  zstream.avail_out = buf_size;
431  ret = inflate(&zstream, Z_PARTIAL_FLUSH);
432  if (ret != Z_OK && ret != Z_STREAM_END) {
433  ret = AVERROR_EXTERNAL;
434  goto fail;
435  }
436  bp->len += zstream.next_out - buf;
437  if (ret == Z_STREAM_END)
438  break;
439  }
440  inflateEnd(&zstream);
441  bp->str[bp->len] = 0;
442  return 0;
443 
444 fail:
445  inflateEnd(&zstream);
446  av_bprint_finalize(bp, NULL);
447  return ret;
448 }
449 
450 static uint8_t *iso88591_to_utf8(const uint8_t *in, size_t size_in)
451 {
452  size_t extra = 0, i;
453  uint8_t *out, *q;
454 
455  for (i = 0; i < size_in; i++)
456  extra += in[i] >= 0x80;
457  if (size_in == SIZE_MAX || extra > SIZE_MAX - size_in - 1)
458  return NULL;
459  q = out = av_malloc(size_in + extra + 1);
460  if (!out)
461  return NULL;
462  for (i = 0; i < size_in; i++) {
463  if (in[i] >= 0x80) {
464  *(q++) = 0xC0 | (in[i] >> 6);
465  *(q++) = 0x80 | (in[i] & 0x3F);
466  } else {
467  *(q++) = in[i];
468  }
469  }
470  *(q++) = 0;
471  return out;
472 }
473 
474 static int decode_text_chunk(PNGDecContext *s, uint32_t length, int compressed,
475  AVDictionary **dict)
476 {
477  int ret, method;
478  const uint8_t *data = s->gb.buffer;
479  const uint8_t *data_end = data + length;
480  const uint8_t *keyword = data;
481  const uint8_t *keyword_end = memchr(keyword, 0, data_end - keyword);
482  uint8_t *kw_utf8 = NULL, *text, *txt_utf8 = NULL;
483  unsigned text_len;
484  AVBPrint bp;
485 
486  if (!keyword_end)
487  return AVERROR_INVALIDDATA;
488  data = keyword_end + 1;
489 
490  if (compressed) {
491  if (data == data_end)
492  return AVERROR_INVALIDDATA;
493  method = *(data++);
494  if (method)
495  return AVERROR_INVALIDDATA;
496  if ((ret = decode_zbuf(&bp, data, data_end)) < 0)
497  return ret;
498  text_len = bp.len;
499  av_bprint_finalize(&bp, (char **)&text);
500  if (!text)
501  return AVERROR(ENOMEM);
502  } else {
503  text = (uint8_t *)data;
504  text_len = data_end - text;
505  }
506 
507  kw_utf8 = iso88591_to_utf8(keyword, keyword_end - keyword);
508  txt_utf8 = iso88591_to_utf8(text, text_len);
509  if (text != data)
510  av_free(text);
511  if (!(kw_utf8 && txt_utf8)) {
512  av_free(kw_utf8);
513  av_free(txt_utf8);
514  return AVERROR(ENOMEM);
515  }
516 
517  av_dict_set(dict, kw_utf8, txt_utf8,
519  return 0;
520 }
521 
523  uint32_t length)
524 {
525  if (length != 13)
526  return AVERROR_INVALIDDATA;
527  s->width = bytestream2_get_be32(&s->gb);
528  s->height = bytestream2_get_be32(&s->gb);
529  if (av_image_check_size(s->width, s->height, 0, avctx)) {
530  s->width = s->height = 0;
531  av_log(avctx, AV_LOG_ERROR, "Invalid image size\n");
532  return AVERROR_INVALIDDATA;
533  }
534  s->bit_depth = bytestream2_get_byte(&s->gb);
535  s->color_type = bytestream2_get_byte(&s->gb);
536  s->compression_type = bytestream2_get_byte(&s->gb);
537  s->filter_type = bytestream2_get_byte(&s->gb);
538  s->interlace_type = bytestream2_get_byte(&s->gb);
539  bytestream2_skip(&s->gb, 4); /* crc */
540  s->state |= PNG_IHDR;
541  if (avctx->debug & FF_DEBUG_PICT_INFO)
542  av_log(avctx, AV_LOG_DEBUG, "width=%d height=%d depth=%d color_type=%d "
543  "compression_type=%d filter_type=%d interlace_type=%d\n",
544  s->width, s->height, s->bit_depth, s->color_type,
546 
547  return 0;
548 }
549 
551 {
552  if (s->state & PNG_IDAT) {
553  av_log(avctx, AV_LOG_ERROR, "pHYs after IDAT\n");
554  return AVERROR_INVALIDDATA;
555  }
556  avctx->sample_aspect_ratio.num = bytestream2_get_be32(&s->gb);
557  avctx->sample_aspect_ratio.den = bytestream2_get_be32(&s->gb);
558  if (avctx->sample_aspect_ratio.num < 0 || avctx->sample_aspect_ratio.den < 0)
559  avctx->sample_aspect_ratio = (AVRational){ 0, 1 };
560  bytestream2_skip(&s->gb, 1); /* unit specifier */
561  bytestream2_skip(&s->gb, 4); /* crc */
562 
563  return 0;
564 }
565 
567  uint32_t length, AVFrame *p)
568 {
569  int ret;
570 
571  if (!(s->state & PNG_IHDR)) {
572  av_log(avctx, AV_LOG_ERROR, "IDAT without IHDR\n");
573  return AVERROR_INVALIDDATA;
574  }
575  if (!(s->state & PNG_IDAT)) {
576  /* init image info */
577  avctx->width = s->width;
578  avctx->height = s->height;
579 
581  s->bits_per_pixel = s->bit_depth * s->channels;
582  s->bpp = (s->bits_per_pixel + 7) >> 3;
583  s->row_size = (avctx->width * s->bits_per_pixel + 7) >> 3;
584 
585  if ((s->bit_depth == 2 || s->bit_depth == 4 || s->bit_depth == 8) &&
587  avctx->pix_fmt = AV_PIX_FMT_RGB24;
588  } else if ((s->bit_depth == 2 || s->bit_depth == 4 || s->bit_depth == 8) &&
590  avctx->pix_fmt = AV_PIX_FMT_RGBA;
591  } else if ((s->bit_depth == 2 || s->bit_depth == 4 || s->bit_depth == 8) &&
593  avctx->pix_fmt = AV_PIX_FMT_GRAY8;
594  } else if (s->bit_depth == 16 &&
596  avctx->pix_fmt = AV_PIX_FMT_GRAY16BE;
597  } else if (s->bit_depth == 16 &&
599  avctx->pix_fmt = AV_PIX_FMT_RGB48BE;
600  } else if (s->bit_depth == 16 &&
602  avctx->pix_fmt = AV_PIX_FMT_RGBA64BE;
603  } else if ((s->bits_per_pixel == 1 || s->bits_per_pixel == 2 || s->bits_per_pixel == 4 || s->bits_per_pixel == 8) &&
605  avctx->pix_fmt = AV_PIX_FMT_PAL8;
606  } else if (s->bit_depth == 1 && s->bits_per_pixel == 1) {
607  avctx->pix_fmt = AV_PIX_FMT_MONOBLACK;
608  } else if (s->bit_depth == 8 &&
610  avctx->pix_fmt = AV_PIX_FMT_YA8;
611  } else if (s->bit_depth == 16 &&
613  avctx->pix_fmt = AV_PIX_FMT_YA16BE;
614  } else {
615  av_log(avctx, AV_LOG_ERROR, "unsupported bit depth %d "
616  "and color type %d\n",
617  s->bit_depth, s->color_type);
618  return AVERROR_INVALIDDATA;
619  }
620 
621  if ((ret = ff_thread_get_buffer(avctx, &s->picture, AV_GET_BUFFER_FLAG_REF)) < 0)
622  return ret;
623  ff_thread_finish_setup(avctx);
624 
626  p->key_frame = 1;
628 
629  /* compute the compressed row size */
630  if (!s->interlace_type) {
631  s->crow_size = s->row_size + 1;
632  } else {
633  s->pass = 0;
635  s->bits_per_pixel,
636  s->width);
637  s->crow_size = s->pass_row_size + 1;
638  }
639  av_dlog(avctx, "row_size=%d crow_size =%d\n",
640  s->row_size, s->crow_size);
641  s->image_buf = p->data[0];
642  s->image_linesize = p->linesize[0];
643  /* copy the palette if needed */
644  if (avctx->pix_fmt == AV_PIX_FMT_PAL8)
645  memcpy(p->data[1], s->palette, 256 * sizeof(uint32_t));
646  /* empty row is used if differencing to the first row */
648  if (!s->last_row)
649  return AVERROR_INVALIDDATA;
650  if (s->interlace_type ||
653  if (!s->tmp_row)
654  return AVERROR_INVALIDDATA;
655  }
656  /* compressed row */
658  if (!s->buffer)
659  return AVERROR(ENOMEM);
660 
661  /* we want crow_buf+1 to be 16-byte aligned */
662  s->crow_buf = s->buffer + 15;
663  s->zstream.avail_out = s->crow_size;
664  s->zstream.next_out = s->crow_buf;
665  }
666  s->state |= PNG_IDAT;
667  if ((ret = png_decode_idat(s, length)) < 0)
668  return ret;
669  bytestream2_skip(&s->gb, 4); /* crc */
670 
671  return 0;
672 }
673 
675  uint32_t length)
676 {
677  int n, i, r, g, b;
678 
679  if ((length % 3) != 0 || length > 256 * 3)
680  return AVERROR_INVALIDDATA;
681  /* read the palette */
682  n = length / 3;
683  for (i = 0; i < n; i++) {
684  r = bytestream2_get_byte(&s->gb);
685  g = bytestream2_get_byte(&s->gb);
686  b = bytestream2_get_byte(&s->gb);
687  s->palette[i] = (0xFFU << 24) | (r << 16) | (g << 8) | b;
688  }
689  for (; i < 256; i++)
690  s->palette[i] = (0xFFU << 24);
691  s->state |= PNG_PLTE;
692  bytestream2_skip(&s->gb, 4); /* crc */
693 
694  return 0;
695 }
696 
698  uint32_t length)
699 {
700  int v, i;
701 
702  /* read the transparency. XXX: Only palette mode supported */
704  length > 256 ||
705  !(s->state & PNG_PLTE))
706  return AVERROR_INVALIDDATA;
707  for (i = 0; i < length; i++) {
708  v = bytestream2_get_byte(&s->gb);
709  s->palette[i] = (s->palette[i] & 0x00ffffff) | (v << 24);
710  }
711  bytestream2_skip(&s->gb, 4); /* crc */
712 
713  return 0;
714 }
715 
717 {
718  if (s->bits_per_pixel == 1 && s->color_type == PNG_COLOR_TYPE_PALETTE) {
719  int i, j, k;
720  uint8_t *pd = p->data[0];
721  for (j = 0; j < s->height; j++) {
722  i = s->width / 8;
723  for (k = 7; k >= 1; k--)
724  if ((s->width&7) >= k)
725  pd[8*i + k - 1] = (pd[i]>>8-k) & 1;
726  for (i--; i >= 0; i--) {
727  pd[8*i + 7]= pd[i] & 1;
728  pd[8*i + 6]= (pd[i]>>1) & 1;
729  pd[8*i + 5]= (pd[i]>>2) & 1;
730  pd[8*i + 4]= (pd[i]>>3) & 1;
731  pd[8*i + 3]= (pd[i]>>4) & 1;
732  pd[8*i + 2]= (pd[i]>>5) & 1;
733  pd[8*i + 1]= (pd[i]>>6) & 1;
734  pd[8*i + 0]= pd[i]>>7;
735  }
736  pd += s->image_linesize;
737  }
738  } else if (s->bits_per_pixel == 2) {
739  int i, j;
740  uint8_t *pd = p->data[0];
741  for (j = 0; j < s->height; j++) {
742  i = s->width / 4;
744  if ((s->width&3) >= 3) pd[4*i + 2]= (pd[i] >> 2) & 3;
745  if ((s->width&3) >= 2) pd[4*i + 1]= (pd[i] >> 4) & 3;
746  if ((s->width&3) >= 1) pd[4*i + 0]= pd[i] >> 6;
747  for (i--; i >= 0; i--) {
748  pd[4*i + 3]= pd[i] & 3;
749  pd[4*i + 2]= (pd[i]>>2) & 3;
750  pd[4*i + 1]= (pd[i]>>4) & 3;
751  pd[4*i + 0]= pd[i]>>6;
752  }
753  } else {
754  if ((s->width&3) >= 3) pd[4*i + 2]= ((pd[i]>>2) & 3)*0x55;
755  if ((s->width&3) >= 2) pd[4*i + 1]= ((pd[i]>>4) & 3)*0x55;
756  if ((s->width&3) >= 1) pd[4*i + 0]= ( pd[i]>>6 )*0x55;
757  for (i--; i >= 0; i--) {
758  pd[4*i + 3]= ( pd[i] & 3)*0x55;
759  pd[4*i + 2]= ((pd[i]>>2) & 3)*0x55;
760  pd[4*i + 1]= ((pd[i]>>4) & 3)*0x55;
761  pd[4*i + 0]= ( pd[i]>>6 )*0x55;
762  }
763  }
764  pd += s->image_linesize;
765  }
766  } else if (s->bits_per_pixel == 4) {
767  int i, j;
768  uint8_t *pd = p->data[0];
769  for (j = 0; j < s->height; j++) {
770  i = s->width/2;
772  if (s->width&1) pd[2*i+0]= pd[i]>>4;
773  for (i--; i >= 0; i--) {
774  pd[2*i + 1] = pd[i] & 15;
775  pd[2*i + 0] = pd[i] >> 4;
776  }
777  } else {
778  if (s->width & 1) pd[2*i + 0]= (pd[i] >> 4) * 0x11;
779  for (i--; i >= 0; i--) {
780  pd[2*i + 1] = (pd[i] & 15) * 0x11;
781  pd[2*i + 0] = (pd[i] >> 4) * 0x11;
782  }
783  }
784  pd += s->image_linesize;
785  }
786  }
787 }
788 
790  uint32_t length)
791 {
792  uint32_t sequence_number, width, height, x_offset, y_offset;
793 
794  if (length != 26)
795  return AVERROR_INVALIDDATA;
796 
797  sequence_number = bytestream2_get_be32(&s->gb);
798  width = bytestream2_get_be32(&s->gb);
799  height = bytestream2_get_be32(&s->gb);
800  x_offset = bytestream2_get_be32(&s->gb);
801  y_offset = bytestream2_get_be32(&s->gb);
802  bytestream2_skip(&s->gb, 10); /* delay_num (2)
803  * delay_den (2)
804  * dispose_op (1)
805  * blend_op (1)
806  * crc (4)
807  */
808 
809  if (width != s->width || height != s->height ||
810  x_offset != 0 || y_offset != 0) {
811  if (sequence_number == 0)
812  return AVERROR_INVALIDDATA;
813  avpriv_request_sample(avctx, "non key frames");
814  return AVERROR_PATCHWELCOME;
815  }
816 
817  return 0;
818 }
819 
821  AVFrame *p, AVPacket *avpkt)
822 {
823  AVDictionary *metadata = NULL;
824  uint32_t tag, length;
825  int decode_next_dat = 0;
826  int ret = AVERROR_INVALIDDATA;
827 
828  for (;;) {
829  length = bytestream2_get_bytes_left(&s->gb);
830  if (length <= 0) {
831  if (avctx->codec_id == AV_CODEC_ID_APNG && length == 0) {
832  if (!(s->state & PNG_IDAT))
833  return 0;
834  else
835  goto exit_loop;
836  }
837  av_log(avctx, AV_LOG_ERROR, "%d bytes left\n", length);
838  if ( s->state & PNG_ALLIMAGE
840  goto exit_loop;
841  goto fail;
842  }
843 
844  length = bytestream2_get_be32(&s->gb);
845  if (length > 0x7fffffff || length > bytestream2_get_bytes_left(&s->gb)) {
846  av_log(avctx, AV_LOG_ERROR, "chunk too big\n");
847  goto fail;
848  }
849  tag = bytestream2_get_le32(&s->gb);
850  if (avctx->debug & FF_DEBUG_STARTCODE)
851  av_log(avctx, AV_LOG_DEBUG, "png: tag=%c%c%c%c length=%u\n",
852  (tag & 0xff),
853  ((tag >> 8) & 0xff),
854  ((tag >> 16) & 0xff),
855  ((tag >> 24) & 0xff), length);
856  switch (tag) {
857  case MKTAG('I', 'H', 'D', 'R'):
858  if (decode_ihdr_chunk(avctx, s, length) < 0)
859  goto fail;
860  break;
861  case MKTAG('p', 'H', 'Y', 's'):
862  if (decode_phys_chunk(avctx, s) < 0)
863  goto fail;
864  break;
865  case MKTAG('f', 'c', 'T', 'L'):
866  if (avctx->codec_id != AV_CODEC_ID_APNG)
867  goto skip_tag;
868  if ((ret = decode_fctl_chunk(avctx, s, length)) < 0)
869  goto fail;
870  decode_next_dat = 1;
871  break;
872  case MKTAG('f', 'd', 'A', 'T'):
873  if (avctx->codec_id != AV_CODEC_ID_APNG)
874  goto skip_tag;
875  if (!decode_next_dat)
876  goto fail;
877  bytestream2_get_be32(&s->gb);
878  length -= 4;
879  /* fallthrough */
880  case MKTAG('I', 'D', 'A', 'T'):
881  if (avctx->codec_id == AV_CODEC_ID_APNG && !decode_next_dat)
882  goto skip_tag;
883  if (decode_idat_chunk(avctx, s, length, p) < 0)
884  goto fail;
885  break;
886  case MKTAG('P', 'L', 'T', 'E'):
887  if (decode_plte_chunk(avctx, s, length) < 0)
888  goto skip_tag;
889  break;
890  case MKTAG('t', 'R', 'N', 'S'):
891  if (decode_trns_chunk(avctx, s, length) < 0)
892  goto skip_tag;
893  break;
894  case MKTAG('t', 'E', 'X', 't'):
895  if (decode_text_chunk(s, length, 0, &metadata) < 0)
896  av_log(avctx, AV_LOG_WARNING, "Broken tEXt chunk\n");
897  bytestream2_skip(&s->gb, length + 4);
898  break;
899  case MKTAG('z', 'T', 'X', 't'):
900  if (decode_text_chunk(s, length, 1, &metadata) < 0)
901  av_log(avctx, AV_LOG_WARNING, "Broken zTXt chunk\n");
902  bytestream2_skip(&s->gb, length + 4);
903  break;
904  case MKTAG('I', 'E', 'N', 'D'):
905  if (!(s->state & PNG_ALLIMAGE))
906  av_log(avctx, AV_LOG_ERROR, "IEND without all image\n");
907  if (!(s->state & (PNG_ALLIMAGE|PNG_IDAT))) {
908  goto fail;
909  }
910  bytestream2_skip(&s->gb, 4); /* crc */
911  goto exit_loop;
912  default:
913  /* skip tag */
914 skip_tag:
915  bytestream2_skip(&s->gb, length + 4);
916  break;
917  }
918  }
919 exit_loop:
920 
921  if (s->bits_per_pixel <= 4)
922  handle_small_bpp(s, p);
923 
924  /* handle p-frames only if a predecessor frame is available */
925  if (s->last_picture.f->data[0]) {
926  if ( !(avpkt->flags & AV_PKT_FLAG_KEY) && avctx->codec_tag != AV_RL32("MPNG")
927  && s->last_picture.f->width == p->width
928  && s->last_picture.f->height== p->height
929  && s->last_picture.f->format== p->format
930  ) {
931  int i, j;
932  uint8_t *pd = p->data[0];
933  uint8_t *pd_last = s->last_picture.f->data[0];
934  int ls = FFMIN(av_image_get_linesize(p->format, s->width, 0), s->width * s->bpp);
935 
936  ff_thread_await_progress(&s->last_picture, INT_MAX, 0);
937  for (j = 0; j < s->height; j++) {
938  for (i = 0; i < ls; i++)
939  pd[i] += pd_last[i];
940  pd += s->image_linesize;
941  pd_last += s->image_linesize;
942  }
943  }
944  }
945  ff_thread_report_progress(&s->picture, INT_MAX, 0);
946 
947  av_frame_set_metadata(p, metadata);
948  metadata = NULL;
949  return 0;
950 
951 fail:
952  av_dict_free(&metadata);
953  ff_thread_report_progress(&s->picture, INT_MAX, 0);
954  return ret;
955 }
956 
957 #if CONFIG_PNG_DECODER
958 static int decode_frame_png(AVCodecContext *avctx,
959  void *data, int *got_frame,
960  AVPacket *avpkt)
961 {
962  PNGDecContext *const s = avctx->priv_data;
963  const uint8_t *buf = avpkt->data;
964  int buf_size = avpkt->size;
965  AVFrame *p;
966  int64_t sig;
967  int ret;
968 
971  p = s->picture.f;
972 
973  bytestream2_init(&s->gb, buf, buf_size);
974 
975  /* check signature */
976  sig = bytestream2_get_be64(&s->gb);
977  if (sig != PNGSIG &&
978  sig != MNGSIG) {
979  av_log(avctx, AV_LOG_ERROR, "Missing png signature\n");
980  return AVERROR_INVALIDDATA;
981  }
982 
983  s->y = s->state = 0;
984 
985  /* init the zlib */
986  s->zstream.zalloc = ff_png_zalloc;
987  s->zstream.zfree = ff_png_zfree;
988  s->zstream.opaque = NULL;
989  ret = inflateInit(&s->zstream);
990  if (ret != Z_OK) {
991  av_log(avctx, AV_LOG_ERROR, "inflateInit returned error %d\n", ret);
992  return AVERROR_EXTERNAL;
993  }
994 
995  if ((ret = decode_frame_common(avctx, s, p, avpkt)) < 0)
996  goto the_end;
997 
998  if ((ret = av_frame_ref(data, s->picture.f)) < 0)
999  return ret;
1000 
1001  *got_frame = 1;
1002 
1003  ret = bytestream2_tell(&s->gb);
1004 the_end:
1005  inflateEnd(&s->zstream);
1006  s->crow_buf = NULL;
1007  return ret;
1008 }
1009 #endif
1010 
1011 #if CONFIG_APNG_DECODER
1012 static int decode_frame_apng(AVCodecContext *avctx,
1013  void *data, int *got_frame,
1014  AVPacket *avpkt)
1015 {
1016  PNGDecContext *const s = avctx->priv_data;
1017  int ret;
1018  AVFrame *p;
1019 
1022  p = s->picture.f;
1023 
1024  if (!(s->state & PNG_IHDR)) {
1025  if (!avctx->extradata_size)
1026  return AVERROR_INVALIDDATA;
1027 
1028  /* only init fields, there is no zlib use in extradata */
1029  s->zstream.zalloc = ff_png_zalloc;
1030  s->zstream.zfree = ff_png_zfree;
1031 
1032  bytestream2_init(&s->gb, avctx->extradata, avctx->extradata_size);
1033  if ((ret = decode_frame_common(avctx, s, p, avpkt)) < 0)
1034  goto end;
1035  }
1036 
1037  /* reset state for a new frame */
1038  if ((ret = inflateInit(&s->zstream)) != Z_OK) {
1039  av_log(avctx, AV_LOG_ERROR, "inflateInit returned error %d\n", ret);
1040  ret = AVERROR_EXTERNAL;
1041  goto end;
1042  }
1043  s->y = 0;
1044  s->state &= ~(PNG_IDAT | PNG_ALLIMAGE);
1045  bytestream2_init(&s->gb, avpkt->data, avpkt->size);
1046  if ((ret = decode_frame_common(avctx, s, p, avpkt)) < 0)
1047  goto end;
1048 
1049  if (!(s->state & PNG_ALLIMAGE))
1050  av_log(avctx, AV_LOG_WARNING, "Frame did not contain a complete image\n");
1051  if (!(s->state & (PNG_ALLIMAGE|PNG_IDAT))) {
1052  ret = AVERROR_INVALIDDATA;
1053  goto end;
1054  }
1055  if ((ret = av_frame_ref(data, s->picture.f)) < 0)
1056  goto end;
1057 
1058  *got_frame = 1;
1059  ret = bytestream2_tell(&s->gb);
1060 
1061 end:
1062  inflateEnd(&s->zstream);
1063  return ret;
1064 }
1065 #endif
1066 
1068 {
1069  PNGDecContext *psrc = src->priv_data;
1070  PNGDecContext *pdst = dst->priv_data;
1071 
1072  if (dst == src)
1073  return 0;
1074 
1075  ff_thread_release_buffer(dst, &pdst->picture);
1076  if (psrc->picture.f->data[0])
1077  return ff_thread_ref_frame(&pdst->picture, &psrc->picture);
1078 
1079  return 0;
1080 }
1081 
1083 {
1084  PNGDecContext *s = avctx->priv_data;
1085 
1086  s->avctx = avctx;
1087  s->last_picture.f = av_frame_alloc();
1088  s->picture.f = av_frame_alloc();
1089  if (!s->last_picture.f || !s->picture.f)
1090  return AVERROR(ENOMEM);
1091 
1092  if (!avctx->internal->is_copy) {
1093  avctx->internal->allocate_progress = 1;
1094  ff_pngdsp_init(&s->dsp);
1095  }
1096 
1097  return 0;
1098 }
1099 
1101 {
1102  PNGDecContext *s = avctx->priv_data;
1103 
1106  ff_thread_release_buffer(avctx, &s->picture);
1107  av_frame_free(&s->picture.f);
1108  av_freep(&s->buffer);
1109  s->buffer_size = 0;
1110  av_freep(&s->last_row);
1111  s->last_row_size = 0;
1112  av_freep(&s->tmp_row);
1113  s->tmp_row_size = 0;
1114 
1115  return 0;
1116 }
1117 
1118 #if CONFIG_APNG_DECODER
1119 AVCodec ff_apng_decoder = {
1120  .name = "apng",
1121  .long_name = NULL_IF_CONFIG_SMALL("APNG (Animated Portable Network Graphics) image"),
1122  .type = AVMEDIA_TYPE_VIDEO,
1123  .id = AV_CODEC_ID_APNG,
1124  .priv_data_size = sizeof(PNGDecContext),
1125  .init = png_dec_init,
1126  .close = png_dec_end,
1127  .decode = decode_frame_apng,
1129  .update_thread_context = ONLY_IF_THREADS_ENABLED(update_thread_context),
1130  .capabilities = CODEC_CAP_DR1 | CODEC_CAP_FRAME_THREADS /*| CODEC_CAP_DRAW_HORIZ_BAND*/,
1131 };
1132 #endif
1133 
1134 #if CONFIG_PNG_DECODER
1135 AVCodec ff_png_decoder = {
1136  .name = "png",
1137  .long_name = NULL_IF_CONFIG_SMALL("PNG (Portable Network Graphics) image"),
1138  .type = AVMEDIA_TYPE_VIDEO,
1139  .id = AV_CODEC_ID_PNG,
1140  .priv_data_size = sizeof(PNGDecContext),
1141  .init = png_dec_init,
1142  .close = png_dec_end,
1143  .decode = decode_frame_png,
1145  .update_thread_context = ONLY_IF_THREADS_ENABLED(update_thread_context),
1146  .capabilities = CODEC_CAP_DR1 | CODEC_CAP_FRAME_THREADS /*| CODEC_CAP_DRAW_HORIZ_BAND*/,
1147 };
1148 #endif