ffv1dec.c
Go to the documentation of this file.
1 /*
2  * FFV1 decoder
3  *
4  * Copyright (c) 2003-2012 Michael Niedermayer <michaelni@gmx.at>
5  *
6  * This file is part of Libav.
7  *
8  * Libav is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * Libav is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with Libav; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
28 #include "libavutil/avassert.h"
29 #include "libavutil/pixdesc.h"
30 #include "libavutil/crc.h"
31 #include "libavutil/opt.h"
32 #include "libavutil/imgutils.h"
33 #include "avcodec.h"
34 #include "internal.h"
35 #include "get_bits.h"
36 #include "put_bits.h"
37 #include "dsputil.h"
38 #include "rangecoder.h"
39 #include "golomb.h"
40 #include "mathops.h"
41 #include "ffv1.h"
42 
44  int is_signed)
45 {
46  if (get_rac(c, state + 0))
47  return 0;
48  else {
49  int i, e, a;
50  e = 0;
51  while (get_rac(c, state + 1 + FFMIN(e, 9))) // 1..10
52  e++;
53 
54  a = 1;
55  for (i = e - 1; i >= 0; i--)
56  a += a + get_rac(c, state + 22 + FFMIN(i, 9)); // 22..31
57 
58  e = -(is_signed && get_rac(c, state + 11 + FFMIN(e, 10))); // 11..21
59  return (a ^ e) - e;
60  }
61 }
62 
63 static av_noinline int get_symbol(RangeCoder *c, uint8_t *state, int is_signed)
64 {
65  return get_symbol_inline(c, state, is_signed);
66 }
67 
68 static inline int get_vlc_symbol(GetBitContext *gb, VlcState *const state,
69  int bits)
70 {
71  int k, i, v, ret;
72 
73  i = state->count;
74  k = 0;
75  while (i < state->error_sum) { // FIXME: optimize
76  k++;
77  i += i;
78  }
79 
80  assert(k <= 8);
81 
82  v = get_sr_golomb(gb, k, 12, bits);
83  av_dlog(NULL, "v:%d bias:%d error:%d drift:%d count:%d k:%d",
84  v, state->bias, state->error_sum, state->drift, state->count, k);
85 
86 #if 0 // JPEG LS
87  if (k == 0 && 2 * state->drift <= -state->count)
88  v ^= (-1);
89 #else
90  v ^= ((2 * state->drift + state->count) >> 31);
91 #endif
92 
93  ret = fold(v + state->bias, bits);
94 
95  update_vlc_state(state, v);
96 
97  return ret;
98 }
99 
101  int16_t *sample[2],
102  int plane_index, int bits)
103 {
104  PlaneContext *const p = &s->plane[plane_index];
105  RangeCoder *const c = &s->c;
106  int x;
107  int run_count = 0;
108  int run_mode = 0;
109  int run_index = s->run_index;
110 
111  for (x = 0; x < w; x++) {
112  int diff, context, sign;
113 
114  context = get_context(p, sample[1] + x, sample[0] + x, sample[1] + x);
115  if (context < 0) {
116  context = -context;
117  sign = 1;
118  } else
119  sign = 0;
120 
121  av_assert2(context < p->context_count);
122 
123  if (s->ac) {
124  diff = get_symbol_inline(c, p->state[context], 1);
125  } else {
126  if (context == 0 && run_mode == 0)
127  run_mode = 1;
128 
129  if (run_mode) {
130  if (run_count == 0 && run_mode == 1) {
131  if (get_bits1(&s->gb)) {
132  run_count = 1 << ff_log2_run[run_index];
133  if (x + run_count <= w)
134  run_index++;
135  } else {
136  if (ff_log2_run[run_index])
137  run_count = get_bits(&s->gb, ff_log2_run[run_index]);
138  else
139  run_count = 0;
140  if (run_index)
141  run_index--;
142  run_mode = 2;
143  }
144  }
145  run_count--;
146  if (run_count < 0) {
147  run_mode = 0;
148  run_count = 0;
149  diff = get_vlc_symbol(&s->gb, &p->vlc_state[context],
150  bits);
151  if (diff >= 0)
152  diff++;
153  } else
154  diff = 0;
155  } else
156  diff = get_vlc_symbol(&s->gb, &p->vlc_state[context], bits);
157 
158  av_dlog(s->avctx, "count:%d index:%d, mode:%d, x:%d pos:%d\n",
159  run_count, run_index, run_mode, x, get_bits_count(&s->gb));
160  }
161 
162  if (sign)
163  diff = -diff;
164 
165  sample[1][x] = (predict(sample[1] + x, sample[0] + x) + diff) &
166  ((1 << bits) - 1);
167  }
168  s->run_index = run_index;
169 }
170 
171 static void decode_plane(FFV1Context *s, uint8_t *src,
172  int w, int h, int stride, int plane_index)
173 {
174  int x, y;
175  int16_t *sample[2];
176  sample[0] = s->sample_buffer + 3;
177  sample[1] = s->sample_buffer + w + 6 + 3;
178 
179  s->run_index = 0;
180 
181  memset(s->sample_buffer, 0, 2 * (w + 6) * sizeof(*s->sample_buffer));
182 
183  for (y = 0; y < h; y++) {
184  int16_t *temp = sample[0]; // FIXME: try a normal buffer
185 
186  sample[0] = sample[1];
187  sample[1] = temp;
188 
189  sample[1][-1] = sample[0][0];
190  sample[0][w] = sample[0][w - 1];
191 
192 // { START_TIMER
193  if (s->avctx->bits_per_raw_sample <= 8) {
194  decode_line(s, w, sample, plane_index, 8);
195  for (x = 0; x < w; x++)
196  src[x + stride * y] = sample[1][x];
197  } else {
198  decode_line(s, w, sample, plane_index,
200  if (s->packed_at_lsb) {
201  for (x = 0; x < w; x++)
202  ((uint16_t *)(src + stride * y))[x] = sample[1][x];
203  } else {
204  for (x = 0; x < w; x++)
205  ((uint16_t *)(src + stride * y))[x] = sample[1][x] << (16 - s->avctx->bits_per_raw_sample);
206  }
207  }
208 // STOP_TIMER("decode-line") }
209  }
210 }
211 
212 static void decode_rgb_frame(FFV1Context *s, uint8_t *src[3], int w, int h,
213  int stride[3])
214 {
215  int x, y, p;
216  int16_t *sample[4][2];
217  int lbd = s->avctx->bits_per_raw_sample <= 8;
218  int bits = s->avctx->bits_per_raw_sample > 0
220  : 8;
221  int offset = 1 << bits;
222 
223  for (x = 0; x < 4; x++) {
224  sample[x][0] = s->sample_buffer + x * 2 * (w + 6) + 3;
225  sample[x][1] = s->sample_buffer + (x * 2 + 1) * (w + 6) + 3;
226  }
227 
228  s->run_index = 0;
229 
230  memset(s->sample_buffer, 0, 8 * (w + 6) * sizeof(*s->sample_buffer));
231 
232  for (y = 0; y < h; y++) {
233  for (p = 0; p < 3 + s->transparency; p++) {
234  int16_t *temp = sample[p][0]; //FIXME try a normal buffer
235 
236  sample[p][0] = sample[p][1];
237  sample[p][1] = temp;
238 
239  sample[p][1][-1] = sample[p][0][0];
240  sample[p][0][w] = sample[p][0][w - 1];
241  if (lbd)
242  decode_line(s, w, sample[p], (p + 1) / 2, 9);
243  else
244  decode_line(s, w, sample[p], (p + 1) / 2, bits + 1);
245  }
246  for (x = 0; x < w; x++) {
247  int g = sample[0][1][x];
248  int b = sample[1][1][x];
249  int r = sample[2][1][x];
250  int a = sample[3][1][x];
251 
252  b -= offset;
253  r -= offset;
254  g -= (b + r) >> 2;
255  b += g;
256  r += g;
257 
258  if (lbd)
259  *((uint32_t *)(src[0] + x * 4 + stride[0] * y)) = b +
260  (g << 8) + (r << 16) + (a << 24);
261  else {
262  *((uint16_t *)(src[0] + x * 2 + stride[0] * y)) = b;
263  *((uint16_t *)(src[1] + x * 2 + stride[1] * y)) = g;
264  *((uint16_t *)(src[2] + x * 2 + stride[2] * y)) = r;
265  }
266  }
267  }
268 }
269 
271 {
272  RangeCoder *c = &fs->c;
274  unsigned ps, i, context_count;
275  memset(state, 128, sizeof(state));
276 
277  if (fs->ac > 1) {
278  for (i = 1; i < 256; i++) {
279  fs->c.one_state[i] = f->state_transition[i];
280  fs->c.zero_state[256 - i] = 256 - fs->c.one_state[i];
281  }
282  }
283 
284  fs->slice_x = get_symbol(c, state, 0) * f->width;
285  fs->slice_y = get_symbol(c, state, 0) * f->height;
286  fs->slice_width = (get_symbol(c, state, 0) + 1) * f->width + fs->slice_x;
287  fs->slice_height = (get_symbol(c, state, 0) + 1) * f->height + fs->slice_y;
288 
289  fs->slice_x /= f->num_h_slices;
290  fs->slice_y /= f->num_v_slices;
291  fs->slice_width = fs->slice_width / f->num_h_slices - fs->slice_x;
292  fs->slice_height = fs->slice_height / f->num_v_slices - fs->slice_y;
293  if ((unsigned)fs->slice_width > f->width ||
294  (unsigned)fs->slice_height > f->height)
295  return AVERROR_INVALIDDATA;
296  if ((unsigned)fs->slice_x + (uint64_t)fs->slice_width > f->width ||
297  (unsigned)fs->slice_y + (uint64_t)fs->slice_height > f->height)
298  return AVERROR_INVALIDDATA;
299 
300  for (i = 0; i < f->plane_count; i++) {
301  PlaneContext *const p = &fs->plane[i];
302  int idx = get_symbol(c, state, 0);
303  if (idx > (unsigned)f->quant_table_count) {
304  av_log(f->avctx, AV_LOG_ERROR, "quant_table_index out of range\n");
305  return AVERROR_INVALIDDATA;
306  }
307  p->quant_table_index = idx;
308  memcpy(p->quant_table, f->quant_tables[idx], sizeof(p->quant_table));
309  context_count = f->context_count[idx];
310 
311  if (p->context_count < context_count) {
312  av_freep(&p->state);
313  av_freep(&p->vlc_state);
314  }
316  }
317 
318  ps = get_symbol(c, state, 0);
319  if (ps == 1) {
320  f->picture.interlaced_frame = 1;
321  f->picture.top_field_first = 1;
322  } else if (ps == 2) {
323  f->picture.interlaced_frame = 1;
324  f->picture.top_field_first = 0;
325  } else if (ps == 3) {
326  f->picture.interlaced_frame = 0;
327  }
328  f->picture.sample_aspect_ratio.num = get_symbol(c, state, 0);
329  f->picture.sample_aspect_ratio.den = get_symbol(c, state, 0);
330 
331  return 0;
332 }
333 
334 static int decode_slice(AVCodecContext *c, void *arg)
335 {
336  FFV1Context *fs = *(void **)arg;
337  FFV1Context *f = fs->avctx->priv_data;
338  int width, height, x, y, ret;
339  const int ps = (av_pix_fmt_desc_get(c->pix_fmt)->flags & PIX_FMT_PLANAR)
340  ? (c->bits_per_raw_sample > 8) + 1
341  : 4;
342  AVFrame *const p = &f->picture;
343 
344  if (f->version > 2) {
345  if (decode_slice_header(f, fs) < 0) {
346  fs->slice_damaged = 1;
347  return AVERROR_INVALIDDATA;
348  }
349  }
350  if ((ret = ffv1_init_slice_state(f, fs)) < 0)
351  return ret;
352  if (f->picture.key_frame)
353  ffv1_clear_slice_state(f, fs);
354  width = fs->slice_width;
355  height = fs->slice_height;
356  x = fs->slice_x;
357  y = fs->slice_y;
358 
359  if (!fs->ac) {
360  if (f->version == 3 && f->minor_version > 1 || f->version > 3)
361  get_rac(&fs->c, (uint8_t[]) { 129 });
362  fs->ac_byte_count = f->version > 2 || (!x && !y) ? fs->c.bytestream - fs->c.bytestream_start - 1 : 0;
364  (fs->c.bytestream_end - fs->c.bytestream_start -
365  fs->ac_byte_count) * 8);
366  }
367 
368  av_assert1(width && height);
369  if (f->colorspace == 0) {
370  const int chroma_width = -((-width) >> f->chroma_h_shift);
371  const int chroma_height = -((-height) >> f->chroma_v_shift);
372  const int cx = x >> f->chroma_h_shift;
373  const int cy = y >> f->chroma_v_shift;
374  decode_plane(fs, p->data[0] + ps * x + y * p->linesize[0], width,
375  height, p->linesize[0],
376  0);
377 
378  if (f->chroma_planes) {
379  decode_plane(fs, p->data[1] + ps * cx + cy * p->linesize[1],
380  chroma_width, chroma_height, p->linesize[1],
381  1);
382  decode_plane(fs, p->data[2] + ps * cx + cy * p->linesize[2],
383  chroma_width, chroma_height, p->linesize[2],
384  1);
385  }
386  if (fs->transparency)
387  decode_plane(fs, p->data[3] + ps * x + y * p->linesize[3], width,
388  height, p->linesize[3],
389  2);
390  } else {
391  uint8_t *planes[3] = { p->data[0] + ps * x + y * p->linesize[0],
392  p->data[1] + ps * x + y * p->linesize[1],
393  p->data[2] + ps * x + y * p->linesize[2] };
394  decode_rgb_frame(fs, planes, width, height, p->linesize);
395  }
396  if (fs->ac && f->version > 2) {
397  int v;
398  get_rac(&fs->c, (uint8_t[]) { 129 });
399  v = fs->c.bytestream_end - fs->c.bytestream - 2 - 5 * f->ec;
400  if (v) {
401  av_log(f->avctx, AV_LOG_ERROR, "bytestream end mismatching by %d\n",
402  v);
403  fs->slice_damaged = 1;
404  }
405  }
406 
407  emms_c();
408 
409  return 0;
410 }
411 
412 static int read_quant_table(RangeCoder *c, int16_t *quant_table, int scale)
413 {
414  int v;
415  int i = 0;
417 
418  memset(state, 128, sizeof(state));
419 
420  for (v = 0; i < 128; v++) {
421  unsigned len = get_symbol(c, state, 0) + 1;
422 
423  if (len > 128 - i)
424  return -1;
425 
426  while (len--) {
427  quant_table[i] = scale * v;
428  i++;
429  }
430  }
431 
432  for (i = 1; i < 128; i++)
433  quant_table[256 - i] = -quant_table[i];
434  quant_table[128] = -quant_table[127];
435 
436  return 2 * v - 1;
437 }
438 
440  int16_t quant_table[MAX_CONTEXT_INPUTS][256])
441 {
442  int i;
443  int context_count = 1;
444 
445  for (i = 0; i < 5; i++) {
446  context_count *= read_quant_table(c, quant_table[i], context_count);
447  if (context_count > 32768U) {
448  return -1;
449  }
450  }
451  return (context_count + 1) / 2;
452 }
453 
455 {
456  RangeCoder *const c = &f->c;
458  int i, j, k, ret;
459  uint8_t state2[32][CONTEXT_SIZE];
460 
461  memset(state2, 128, sizeof(state2));
462  memset(state, 128, sizeof(state));
463 
465  ff_build_rac_states(c, 0.05 * (1LL << 32), 256 - 8);
466 
467  f->version = get_symbol(c, state, 0);
468  if (f->version > 2) {
469  c->bytestream_end -= 4;
470  f->minor_version = get_symbol(c, state, 0);
471  }
472  f->ac = f->avctx->coder_type = get_symbol(c, state, 0);
473 
474  if (f->ac > 1) {
475  for (i = 1; i < 256; i++)
476  f->state_transition[i] = get_symbol(c, state, 1) + c->one_state[i];
477  }
478 
479  f->colorspace = get_symbol(c, state, 0); //YUV cs type
480  f->avctx->bits_per_raw_sample = get_symbol(c, state, 0);
481  f->chroma_planes = get_rac(c, state);
482  f->chroma_h_shift = get_symbol(c, state, 0);
483  f->chroma_v_shift = get_symbol(c, state, 0);
484  f->transparency = get_rac(c, state);
485  f->plane_count = 2 + f->transparency;
486  f->num_h_slices = 1 + get_symbol(c, state, 0);
487  f->num_v_slices = 1 + get_symbol(c, state, 0);
488 
489  if (f->num_h_slices > (unsigned)f->width ||
490  f->num_v_slices > (unsigned)f->height) {
491  av_log(f->avctx, AV_LOG_ERROR, "too many slices\n");
492  return AVERROR_INVALIDDATA;
493  }
494 
495  f->quant_table_count = get_symbol(c, state, 0);
496  if (f->quant_table_count > (unsigned)MAX_QUANT_TABLES)
497  return AVERROR_INVALIDDATA;
498  for (i = 0; i < f->quant_table_count; i++) {
499  f->context_count[i] = read_quant_tables(c, f->quant_tables[i]);
500  if (f->context_count[i] < 0) {
501  av_log(f->avctx, AV_LOG_ERROR, "read_quant_table error\n");
502  return AVERROR_INVALIDDATA;
503  }
504  }
505  if ((ret = ffv1_allocate_initial_states(f)) < 0)
506  return ret;
507 
508  for (i = 0; i < f->quant_table_count; i++)
509  if (get_rac(c, state)) {
510  for (j = 0; j < f->context_count[i]; j++)
511  for (k = 0; k < CONTEXT_SIZE; k++) {
512  int pred = j ? f->initial_states[i][j - 1][k] : 128;
513  f->initial_states[i][j][k] =
514  (pred + get_symbol(c, state2[k], 1)) & 0xFF;
515  }
516  }
517 
518  if (f->version > 2) {
519  f->ec = get_symbol(c, state, 0);
520  }
521 
522  if (f->version > 2) {
523  unsigned v;
526  if (v) {
527  av_log(f->avctx, AV_LOG_ERROR, "CRC mismatch %X!\n", v);
528  return AVERROR_INVALIDDATA;
529  }
530  }
531 
532  return 0;
533 }
534 
535 
536 static int read_header(FFV1Context *f)
537 {
539  int i, j, context_count = -1;
540  RangeCoder *const c = &f->slice_context[0]->c;
541 
542  memset(state, 128, sizeof(state));
543 
544  if (f->version < 2) {
545  unsigned v = get_symbol(c, state, 0);
546  if (v > 1) {
548  "invalid version %d in version 1 header\n", v);
549  return AVERROR_INVALIDDATA;
550  }
551  f->version = v;
552 
553  f->ac = f->avctx->coder_type = get_symbol(c, state, 0);
554 
555  if (f->ac > 1) {
556  for (i = 1; i < 256; i++)
557  f->state_transition[i] =
558  get_symbol(c, state, 1) + c->one_state[i];
559  }
560 
561  f->colorspace = get_symbol(c, state, 0); //YUV cs type
562 
563  if (f->version > 0)
564  f->avctx->bits_per_raw_sample = get_symbol(c, state, 0);
565 
566  f->chroma_planes = get_rac(c, state);
567  f->chroma_h_shift = get_symbol(c, state, 0);
568  f->chroma_v_shift = get_symbol(c, state, 0);
569  f->transparency = get_rac(c, state);
570  f->plane_count = 2 + f->transparency;
571  }
572 
573  if (f->colorspace == 0) {
574  if (!f->transparency && !f->chroma_planes) {
575  if (f->avctx->bits_per_raw_sample <= 8)
577  else
579  } else if (f->avctx->bits_per_raw_sample <= 8 && !f->transparency) {
580  switch (16 * f->chroma_h_shift + f->chroma_v_shift) {
581  case 0x00:
583  break;
584  case 0x01:
586  break;
587  case 0x10:
589  break;
590  case 0x11:
592  break;
593  case 0x20:
595  break;
596  case 0x22:
598  break;
599  default:
600  av_log(f->avctx, AV_LOG_ERROR, "format not supported\n");
601  return AVERROR(ENOSYS);
602  }
603  } else if (f->avctx->bits_per_raw_sample <= 8 && f->transparency) {
604  switch (16 * f->chroma_h_shift + f->chroma_v_shift) {
605  case 0x00:
607  break;
608  case 0x10:
610  break;
611  case 0x11:
613  break;
614  default:
615  av_log(f->avctx, AV_LOG_ERROR, "format not supported\n");
616  return AVERROR(ENOSYS);
617  }
618  } else if (f->avctx->bits_per_raw_sample == 9) {
619  f->packed_at_lsb = 1;
620  switch (16 * f->chroma_h_shift + f->chroma_v_shift) {
621  case 0x00:
623  break;
624  case 0x10:
626  break;
627  case 0x11:
629  break;
630  default:
631  av_log(f->avctx, AV_LOG_ERROR, "format not supported\n");
632  return AVERROR(ENOSYS);
633  }
634  } else if (f->avctx->bits_per_raw_sample == 10) {
635  f->packed_at_lsb = 1;
636  switch (16 * f->chroma_h_shift + f->chroma_v_shift) {
637  case 0x00:
639  break;
640  case 0x10:
642  break;
643  case 0x11:
645  break;
646  default:
647  av_log(f->avctx, AV_LOG_ERROR, "format not supported\n");
648  return AVERROR(ENOSYS);
649  }
650  } else {
651  switch (16 * f->chroma_h_shift + f->chroma_v_shift) {
652  case 0x00:
654  break;
655  case 0x10:
657  break;
658  case 0x11:
660  break;
661  default:
662  av_log(f->avctx, AV_LOG_ERROR, "format not supported\n");
663  return AVERROR(ENOSYS);
664  }
665  }
666  } else if (f->colorspace == 1) {
667  if (f->chroma_h_shift || f->chroma_v_shift) {
669  "chroma subsampling not supported in this colorspace\n");
670  return AVERROR(ENOSYS);
671  }
672  switch (f->avctx->bits_per_raw_sample) {
673  case 8:
675  break;
676  case 9:
678  break;
679  case 10:
681  break;
682  default:
684  "bit depth %d not supported\n",
686  return AVERROR(ENOSYS);
687  }
688  } else {
689  av_log(f->avctx, AV_LOG_ERROR, "colorspace not supported\n");
690  return AVERROR(ENOSYS);
691  }
692 
693  av_dlog(f->avctx, "%d %d %d\n",
695  if (f->version < 2) {
696  context_count = read_quant_tables(c, f->quant_table);
697  if (context_count < 0) {
698  av_log(f->avctx, AV_LOG_ERROR, "read_quant_table error\n");
699  return AVERROR_INVALIDDATA;
700  }
701  } else if (f->version < 3) {
702  f->slice_count = get_symbol(c, state, 0);
703  } else {
704  const uint8_t *p = c->bytestream_end;
705  for (f->slice_count = 0;
706  f->slice_count < MAX_SLICES && 3 < p - c->bytestream_start;
707  f->slice_count++) {
708  int trailer = 3 + 5 * !!f->ec;
709  int size = AV_RB24(p - trailer);
710  if (size + trailer > p - c->bytestream_start)
711  break;
712  p -= size + trailer;
713  }
714  }
715  if (f->slice_count > (unsigned)MAX_SLICES || f->slice_count <= 0) {
716  av_log(f->avctx, AV_LOG_ERROR, "slice count %d is invalid\n",
717  f->slice_count);
718  return AVERROR_INVALIDDATA;
719  }
720 
721  for (j = 0; j < f->slice_count; j++) {
722  FFV1Context *fs = f->slice_context[j];
723  fs->ac = f->ac;
724  fs->packed_at_lsb = f->packed_at_lsb;
725 
726  fs->slice_damaged = 0;
727 
728  if (f->version == 2) {
729  fs->slice_x = get_symbol(c, state, 0) * f->width;
730  fs->slice_y = get_symbol(c, state, 0) * f->height;
731  fs->slice_width =
732  (get_symbol(c, state, 0) + 1) * f->width + fs->slice_x;
733  fs->slice_height =
734  (get_symbol(c, state, 0) + 1) * f->height + fs->slice_y;
735 
736  fs->slice_x /= f->num_h_slices;
737  fs->slice_y /= f->num_v_slices;
738  fs->slice_width = fs->slice_width / f->num_h_slices - fs->slice_x;
739  fs->slice_height = fs->slice_height / f->num_v_slices - fs->slice_y;
740  if ((unsigned)fs->slice_width > f->width ||
741  (unsigned)fs->slice_height > f->height)
742  return AVERROR_INVALIDDATA;
743  if ((unsigned)fs->slice_x + (uint64_t)fs->slice_width > f->width
744  || (unsigned)fs->slice_y + (uint64_t)fs->slice_height >
745  f->height)
746  return AVERROR_INVALIDDATA;
747  }
748 
749  for (i = 0; i < f->plane_count; i++) {
750  PlaneContext *const p = &fs->plane[i];
751 
752  if (f->version == 2) {
753  int idx = get_symbol(c, state, 0);
754  if (idx > (unsigned)f->quant_table_count) {
756  "quant_table_index out of range\n");
757  return AVERROR_INVALIDDATA;
758  }
759  p->quant_table_index = idx;
760  memcpy(p->quant_table, f->quant_tables[idx],
761  sizeof(p->quant_table));
762  context_count = f->context_count[idx];
763  } else {
764  memcpy(p->quant_table, f->quant_table, sizeof(p->quant_table));
765  }
766 
767  if (f->version <= 2) {
768  av_assert0(context_count >= 0);
769  if (p->context_count < context_count) {
770  av_freep(&p->state);
771  av_freep(&p->vlc_state);
772  }
774  }
775  }
776  }
777  return 0;
778 }
779 
781 {
782  FFV1Context *f = avctx->priv_data;
783  int ret;
784 
785  ffv1_common_init(avctx);
786 
787  if (avctx->extradata && (ret = read_extra_header(f)) < 0)
788  return ret;
789 
790  if ((ret = ffv1_init_slice_contexts(f)) < 0)
791  return ret;
792 
793  return 0;
794 }
795 
797  int *got_frame, AVPacket *avpkt)
798 {
799  const uint8_t *buf = avpkt->data;
800  int buf_size = avpkt->size;
801  FFV1Context *f = avctx->priv_data;
802  RangeCoder *const c = &f->slice_context[0]->c;
803  AVFrame *const p = &f->picture;
804  int i, ret;
805  uint8_t keystate = 128;
806  const uint8_t *buf_p;
807 
808  AVFrame *picture = data;
809 
810  /* release previously stored data */
811  if (p->data[0])
812  avctx->release_buffer(avctx, p);
813 
814  ff_init_range_decoder(c, buf, buf_size);
815  ff_build_rac_states(c, 0.05 * (1LL << 32), 256 - 8);
816 
817  p->pict_type = AV_PICTURE_TYPE_I; //FIXME I vs. P
818  if (get_rac(c, &keystate)) {
819  p->key_frame = 1;
820  f->key_frame_ok = 0;
821  if ((ret = read_header(f)) < 0)
822  return ret;
823  f->key_frame_ok = 1;
824  } else {
825  if (!f->key_frame_ok) {
826  av_log(avctx, AV_LOG_ERROR,
827  "Cannot decode non-keyframe without valid keyframe\n");
828  return AVERROR_INVALIDDATA;
829  }
830  p->key_frame = 0;
831  }
832 
833  p->reference = 3; //for error concealment
834  if ((ret = ff_get_buffer(avctx, p)) < 0) {
835  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
836  return ret;
837  }
838 
839  if (avctx->debug & FF_DEBUG_PICT_INFO)
840  av_log(avctx, AV_LOG_DEBUG,
841  "ver:%d keyframe:%d coder:%d ec:%d slices:%d bps:%d\n",
842  f->version, p->key_frame, f->ac, f->ec, f->slice_count,
844 
845  buf_p = buf + buf_size;
846  for (i = f->slice_count - 1; i >= 0; i--) {
847  FFV1Context *fs = f->slice_context[i];
848  int trailer = 3 + 5 * !!f->ec;
849  int v;
850 
851  if (i || f->version > 2)
852  v = AV_RB24(buf_p - trailer) + trailer;
853  else
854  v = buf_p - c->bytestream_start;
855  if (buf_p - c->bytestream_start < v) {
856  av_log(avctx, AV_LOG_ERROR, "Slice pointer chain broken\n");
857  return AVERROR_INVALIDDATA;
858  }
859  buf_p -= v;
860 
861  if (f->ec) {
862  unsigned crc = av_crc(av_crc_get_table(AV_CRC_32_IEEE), 0, buf_p, v);
863  if (crc) {
864  av_log(f->avctx, AV_LOG_ERROR, "CRC mismatch %X!\n", crc);
865  fs->slice_damaged = 1;
866  }
867  }
868 
869  if (i) {
870  ff_init_range_decoder(&fs->c, buf_p, v);
871  } else
872  fs->c.bytestream_end = (uint8_t *)(buf_p + v);
873  }
874 
875  avctx->execute(avctx, decode_slice, &f->slice_context[0], NULL,
876  f->slice_count,
877  sizeof(void *));
878 
879  for (i = f->slice_count - 1; i >= 0; i--) {
880  FFV1Context *fs = f->slice_context[i];
881  int j;
882  if (fs->slice_damaged && f->last_picture.data[0]) {
883  const uint8_t *src[4];
884  uint8_t *dst[4];
885  for (j = 0; j < 4; j++) {
886  int sh = (j == 1 || j == 2) ? f->chroma_h_shift : 0;
887  int sv = (j == 1 || j == 2) ? f->chroma_v_shift : 0;
888  dst[j] = f->picture.data[j] + f->picture.linesize[j] *
889  (fs->slice_y >> sv) + (fs->slice_x >> sh);
890  src[j] = f->last_picture.data[j] +
891  f->last_picture.linesize[j] *
892  (fs->slice_y >> sv) + (fs->slice_x >> sh);
893  }
894  av_image_copy(dst, f->picture.linesize, (const uint8_t **)src,
896  avctx->pix_fmt, fs->slice_width,
897  fs->slice_height);
898  }
899  }
900 
901  f->picture_number++;
902 
903  *picture = *p;
904  *got_frame = 1;
905 
907 
908  return buf_size;
909 }
910 
912  .name = "ffv1",
913  .type = AVMEDIA_TYPE_VIDEO,
914  .id = AV_CODEC_ID_FFV1,
915  .priv_data_size = sizeof(FFV1Context),
917  .close = ffv1_close,
919  .capabilities = CODEC_CAP_DR1 /*| CODEC_CAP_DRAW_HORIZ_BAND*/ |
921  .long_name = NULL_IF_CONFIG_SMALL("FFmpeg video codec #1"),
922 };