FFmpeg
 All Data Structures Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
svq1dec.c
Go to the documentation of this file.
1 /*
2  * SVQ1 decoder
3  * ported to MPlayer by Arpi <arpi@thot.banki.hu>
4  * ported to libavcodec by Nick Kurshev <nickols_k@mail.ru>
5  *
6  * Copyright (C) 2002 the xine project
7  * Copyright (C) 2002 the ffmpeg project
8  *
9  * SVQ1 Encoder (c) 2004 Mike Melanson <melanson@pcisys.net>
10  *
11  * This file is part of FFmpeg.
12  *
13  * FFmpeg is free software; you can redistribute it and/or
14  * modify it under the terms of the GNU Lesser General Public
15  * License as published by the Free Software Foundation; either
16  * version 2.1 of the License, or (at your option) any later version.
17  *
18  * FFmpeg is distributed in the hope that it will be useful,
19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
21  * Lesser General Public License for more details.
22  *
23  * You should have received a copy of the GNU Lesser General Public
24  * License along with FFmpeg; if not, write to the Free Software
25  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
26  */
27 
28 /**
29  * @file
30  * Sorenson Vector Quantizer #1 (SVQ1) video codec.
31  * For more information of the SVQ1 algorithm, visit:
32  * http://www.pcisys.net/~melanson/codecs/
33  */
34 
35 #include "avcodec.h"
36 #include "dsputil.h"
37 #include "get_bits.h"
38 #include "internal.h"
39 #include "mathops.h"
40 #include "svq1.h"
41 
42 #undef NDEBUG
43 #include <assert.h>
44 
45 extern const uint8_t ff_mvtab[33][2];
46 
47 static VLC svq1_block_type;
48 static VLC svq1_motion_component;
49 static VLC svq1_intra_multistage[6];
50 static VLC svq1_inter_multistage[6];
51 static VLC svq1_intra_mean;
52 static VLC svq1_inter_mean;
53 
54 /* motion vector (prediction) */
55 typedef struct svq1_pmv_s {
56  int x;
57  int y;
58 } svq1_pmv;
59 
60 typedef struct SVQ1Context {
61  DSPContext dsp;
62  GetBitContext gb;
63  AVFrame *cur, *prev;
64  int width;
65  int height;
66  int frame_code;
67  int nonref; // 1 if the current frame won't be referenced
68 } SVQ1Context;
69 
70 static const uint8_t string_table[256] = {
71  0x00, 0xD5, 0x7F, 0xAA, 0xFE, 0x2B, 0x81, 0x54,
72  0x29, 0xFC, 0x56, 0x83, 0xD7, 0x02, 0xA8, 0x7D,
73  0x52, 0x87, 0x2D, 0xF8, 0xAC, 0x79, 0xD3, 0x06,
74  0x7B, 0xAE, 0x04, 0xD1, 0x85, 0x50, 0xFA, 0x2F,
75  0xA4, 0x71, 0xDB, 0x0E, 0x5A, 0x8F, 0x25, 0xF0,
76  0x8D, 0x58, 0xF2, 0x27, 0x73, 0xA6, 0x0C, 0xD9,
77  0xF6, 0x23, 0x89, 0x5C, 0x08, 0xDD, 0x77, 0xA2,
78  0xDF, 0x0A, 0xA0, 0x75, 0x21, 0xF4, 0x5E, 0x8B,
79  0x9D, 0x48, 0xE2, 0x37, 0x63, 0xB6, 0x1C, 0xC9,
80  0xB4, 0x61, 0xCB, 0x1E, 0x4A, 0x9F, 0x35, 0xE0,
81  0xCF, 0x1A, 0xB0, 0x65, 0x31, 0xE4, 0x4E, 0x9B,
82  0xE6, 0x33, 0x99, 0x4C, 0x18, 0xCD, 0x67, 0xB2,
83  0x39, 0xEC, 0x46, 0x93, 0xC7, 0x12, 0xB8, 0x6D,
84  0x10, 0xC5, 0x6F, 0xBA, 0xEE, 0x3B, 0x91, 0x44,
85  0x6B, 0xBE, 0x14, 0xC1, 0x95, 0x40, 0xEA, 0x3F,
86  0x42, 0x97, 0x3D, 0xE8, 0xBC, 0x69, 0xC3, 0x16,
87  0xEF, 0x3A, 0x90, 0x45, 0x11, 0xC4, 0x6E, 0xBB,
88  0xC6, 0x13, 0xB9, 0x6C, 0x38, 0xED, 0x47, 0x92,
89  0xBD, 0x68, 0xC2, 0x17, 0x43, 0x96, 0x3C, 0xE9,
90  0x94, 0x41, 0xEB, 0x3E, 0x6A, 0xBF, 0x15, 0xC0,
91  0x4B, 0x9E, 0x34, 0xE1, 0xB5, 0x60, 0xCA, 0x1F,
92  0x62, 0xB7, 0x1D, 0xC8, 0x9C, 0x49, 0xE3, 0x36,
93  0x19, 0xCC, 0x66, 0xB3, 0xE7, 0x32, 0x98, 0x4D,
94  0x30, 0xE5, 0x4F, 0x9A, 0xCE, 0x1B, 0xB1, 0x64,
95  0x72, 0xA7, 0x0D, 0xD8, 0x8C, 0x59, 0xF3, 0x26,
96  0x5B, 0x8E, 0x24, 0xF1, 0xA5, 0x70, 0xDA, 0x0F,
97  0x20, 0xF5, 0x5F, 0x8A, 0xDE, 0x0B, 0xA1, 0x74,
98  0x09, 0xDC, 0x76, 0xA3, 0xF7, 0x22, 0x88, 0x5D,
99  0xD6, 0x03, 0xA9, 0x7C, 0x28, 0xFD, 0x57, 0x82,
100  0xFF, 0x2A, 0x80, 0x55, 0x01, 0xD4, 0x7E, 0xAB,
101  0x84, 0x51, 0xFB, 0x2E, 0x7A, 0xAF, 0x05, 0xD0,
102  0xAD, 0x78, 0xD2, 0x07, 0x53, 0x86, 0x2C, 0xF9
103 };
104 
105 #define SVQ1_PROCESS_VECTOR() \
106  for (; level > 0; i++) { \
107  /* process next depth */ \
108  if (i == m) { \
109  m = n; \
110  if (--level == 0) \
111  break; \
112  } \
113  /* divide block if next bit set */ \
114  if (!get_bits1(bitbuf)) \
115  break; \
116  /* add child nodes */ \
117  list[n++] = list[i]; \
118  list[n++] = list[i] + (((level & 1) ? pitch : 1) << ((level >> 1) + 1));\
119  }
120 
121 #define SVQ1_ADD_CODEBOOK() \
122  /* add codebook entries to vector */ \
123  for (j = 0; j < stages; j++) { \
124  n3 = codebook[entries[j]] ^ 0x80808080; \
125  n1 += (n3 & 0xFF00FF00) >> 8; \
126  n2 += n3 & 0x00FF00FF; \
127  } \
128  \
129  /* clip to [0..255] */ \
130  if (n1 & 0xFF00FF00) { \
131  n3 = (n1 >> 15 & 0x00010001 | 0x01000100) - 0x00010001; \
132  n1 += 0x7F007F00; \
133  n1 |= (~n1 >> 15 & 0x00010001 | 0x01000100) - 0x00010001; \
134  n1 &= n3 & 0x00FF00FF; \
135  } \
136  \
137  if (n2 & 0xFF00FF00) { \
138  n3 = (n2 >> 15 & 0x00010001 | 0x01000100) - 0x00010001; \
139  n2 += 0x7F007F00; \
140  n2 |= (~n2 >> 15 & 0x00010001 | 0x01000100) - 0x00010001; \
141  n2 &= n3 & 0x00FF00FF; \
142  }
143 
144 #define SVQ1_CALC_CODEBOOK_ENTRIES(cbook) \
145  codebook = (const uint32_t *)cbook[level]; \
146  if (stages > 0) \
147  bit_cache = get_bits(bitbuf, 4 * stages); \
148  /* calculate codebook entries for this vector */ \
149  for (j = 0; j < stages; j++) { \
150  entries[j] = (((bit_cache >> (4 * (stages - j - 1))) & 0xF) + \
151  16 * j) << (level + 1); \
152  } \
153  mean -= stages * 128; \
154  n4 = (mean << 16) + mean;
155 
156 static int svq1_decode_block_intra(GetBitContext *bitbuf, uint8_t *pixels,
157  int pitch)
158 {
159  uint32_t bit_cache;
160  uint8_t *list[63];
161  uint32_t *dst;
162  const uint32_t *codebook;
163  int entries[6];
164  int i, j, m, n;
165  int mean, stages;
166  unsigned x, y, width, height, level;
167  uint32_t n1, n2, n3, n4;
168 
169  /* initialize list for breadth first processing of vectors */
170  list[0] = pixels;
171 
172  /* recursively process vector */
173  for (i = 0, m = 1, n = 1, level = 5; i < n; i++) {
174  SVQ1_PROCESS_VECTOR();
175 
176  /* destination address and vector size */
177  dst = (uint32_t *)list[i];
178  width = 1 << ((4 + level) / 2);
179  height = 1 << ((3 + level) / 2);
180 
181  /* get number of stages (-1 skips vector, 0 for mean only) */
182  stages = get_vlc2(bitbuf, svq1_intra_multistage[level].table, 3, 3) - 1;
183 
184  if (stages == -1) {
185  for (y = 0; y < height; y++)
186  memset(&dst[y * (pitch / 4)], 0, width);
187  continue; /* skip vector */
188  }
189 
190  if (stages > 0 && level >= 4) {
191  av_dlog(NULL,
192  "Error (svq1_decode_block_intra): invalid vector: stages=%i level=%i\n",
193  stages, level);
194  return AVERROR_INVALIDDATA; /* invalid vector */
195  }
196 
197  mean = get_vlc2(bitbuf, svq1_intra_mean.table, 8, 3);
198 
199  if (stages == 0) {
200  for (y = 0; y < height; y++)
201  memset(&dst[y * (pitch / 4)], mean, width);
202  } else {
203  SVQ1_CALC_CODEBOOK_ENTRIES(ff_svq1_intra_codebooks);
204 
205  for (y = 0; y < height; y++) {
206  for (x = 0; x < width / 4; x++, codebook++) {
207  n1 = n4;
208  n2 = n4;
209  SVQ1_ADD_CODEBOOK()
210  /* store result */
211  dst[x] = n1 << 8 | n2;
212  }
213  dst += pitch / 4;
214  }
215  }
216  }
217 
218  return 0;
219 }
220 
221 static int svq1_decode_block_non_intra(GetBitContext *bitbuf, uint8_t *pixels,
222  int pitch)
223 {
224  uint32_t bit_cache;
225  uint8_t *list[63];
226  uint32_t *dst;
227  const uint32_t *codebook;
228  int entries[6];
229  int i, j, m, n;
230  int mean, stages;
231  int x, y, width, height, level;
232  uint32_t n1, n2, n3, n4;
233 
234  /* initialize list for breadth first processing of vectors */
235  list[0] = pixels;
236 
237  /* recursively process vector */
238  for (i = 0, m = 1, n = 1, level = 5; i < n; i++) {
239  SVQ1_PROCESS_VECTOR();
240 
241  /* destination address and vector size */
242  dst = (uint32_t *)list[i];
243  width = 1 << ((4 + level) / 2);
244  height = 1 << ((3 + level) / 2);
245 
246  /* get number of stages (-1 skips vector, 0 for mean only) */
247  stages = get_vlc2(bitbuf, svq1_inter_multistage[level].table, 3, 2) - 1;
248 
249  if (stages == -1)
250  continue; /* skip vector */
251 
252  if ((stages > 0) && (level >= 4)) {
253  av_dlog(NULL,
254  "Error (svq1_decode_block_non_intra): invalid vector: stages=%i level=%i\n",
255  stages, level);
256  return AVERROR_INVALIDDATA; /* invalid vector */
257  }
258 
259  mean = get_vlc2(bitbuf, svq1_inter_mean.table, 9, 3) - 256;
260 
261  SVQ1_CALC_CODEBOOK_ENTRIES(ff_svq1_inter_codebooks);
262 
263  for (y = 0; y < height; y++) {
264  for (x = 0; x < width / 4; x++, codebook++) {
265  n3 = dst[x];
266  /* add mean value to vector */
267  n1 = n4 + ((n3 & 0xFF00FF00) >> 8);
268  n2 = n4 + (n3 & 0x00FF00FF);
269  SVQ1_ADD_CODEBOOK()
270  /* store result */
271  dst[x] = n1 << 8 | n2;
272  }
273  dst += pitch / 4;
274  }
275  }
276  return 0;
277 }
278 
279 static int svq1_decode_motion_vector(GetBitContext *bitbuf, svq1_pmv *mv,
280  svq1_pmv **pmv)
281 {
282  int diff;
283  int i;
284 
285  for (i = 0; i < 2; i++) {
286  /* get motion code */
287  diff = get_vlc2(bitbuf, svq1_motion_component.table, 7, 2);
288  if (diff < 0)
289  return AVERROR_INVALIDDATA;
290  else if (diff) {
291  if (get_bits1(bitbuf))
292  diff = -diff;
293  }
294 
295  /* add median of motion vector predictors and clip result */
296  if (i == 1)
297  mv->y = sign_extend(diff + mid_pred(pmv[0]->y, pmv[1]->y, pmv[2]->y), 6);
298  else
299  mv->x = sign_extend(diff + mid_pred(pmv[0]->x, pmv[1]->x, pmv[2]->x), 6);
300  }
301 
302  return 0;
303 }
304 
305 static void svq1_skip_block(uint8_t *current, uint8_t *previous,
306  int pitch, int x, int y)
307 {
308  uint8_t *src;
309  uint8_t *dst;
310  int i;
311 
312  src = &previous[x + y * pitch];
313  dst = current;
314 
315  for (i = 0; i < 16; i++) {
316  memcpy(dst, src, 16);
317  src += pitch;
318  dst += pitch;
319  }
320 }
321 
322 static int svq1_motion_inter_block(DSPContext *dsp, GetBitContext *bitbuf,
323  uint8_t *current, uint8_t *previous,
324  int pitch, svq1_pmv *motion, int x, int y)
325 {
326  uint8_t *src;
327  uint8_t *dst;
328  svq1_pmv mv;
329  svq1_pmv *pmv[3];
330  int result;
331 
332  /* predict and decode motion vector */
333  pmv[0] = &motion[0];
334  if (y == 0) {
335  pmv[1] =
336  pmv[2] = pmv[0];
337  } else {
338  pmv[1] = &motion[x / 8 + 2];
339  pmv[2] = &motion[x / 8 + 4];
340  }
341 
342  result = svq1_decode_motion_vector(bitbuf, &mv, pmv);
343  if (result)
344  return result;
345 
346  motion[0].x =
347  motion[x / 8 + 2].x =
348  motion[x / 8 + 3].x = mv.x;
349  motion[0].y =
350  motion[x / 8 + 2].y =
351  motion[x / 8 + 3].y = mv.y;
352 
353  if (y + (mv.y >> 1) < 0)
354  mv.y = 0;
355  if (x + (mv.x >> 1) < 0)
356  mv.x = 0;
357 
358  src = &previous[(x + (mv.x >> 1)) + (y + (mv.y >> 1)) * pitch];
359  dst = current;
360 
361  dsp->put_pixels_tab[0][(mv.y & 1) << 1 | (mv.x & 1)](dst, src, pitch, 16);
362 
363  return 0;
364 }
365 
366 static int svq1_motion_inter_4v_block(DSPContext *dsp, GetBitContext *bitbuf,
367  uint8_t *current, uint8_t *previous,
368  int pitch, svq1_pmv *motion, int x, int y)
369 {
370  uint8_t *src;
371  uint8_t *dst;
372  svq1_pmv mv;
373  svq1_pmv *pmv[4];
374  int i, result;
375 
376  /* predict and decode motion vector (0) */
377  pmv[0] = &motion[0];
378  if (y == 0) {
379  pmv[1] =
380  pmv[2] = pmv[0];
381  } else {
382  pmv[1] = &motion[(x / 8) + 2];
383  pmv[2] = &motion[(x / 8) + 4];
384  }
385 
386  result = svq1_decode_motion_vector(bitbuf, &mv, pmv);
387  if (result)
388  return result;
389 
390  /* predict and decode motion vector (1) */
391  pmv[0] = &mv;
392  if (y == 0) {
393  pmv[1] =
394  pmv[2] = pmv[0];
395  } else {
396  pmv[1] = &motion[(x / 8) + 3];
397  }
398  result = svq1_decode_motion_vector(bitbuf, &motion[0], pmv);
399  if (result)
400  return result;
401 
402  /* predict and decode motion vector (2) */
403  pmv[1] = &motion[0];
404  pmv[2] = &motion[(x / 8) + 1];
405 
406  result = svq1_decode_motion_vector(bitbuf, &motion[(x / 8) + 2], pmv);
407  if (result)
408  return result;
409 
410  /* predict and decode motion vector (3) */
411  pmv[2] = &motion[(x / 8) + 2];
412  pmv[3] = &motion[(x / 8) + 3];
413 
414  result = svq1_decode_motion_vector(bitbuf, pmv[3], pmv);
415  if (result)
416  return result;
417 
418  /* form predictions */
419  for (i = 0; i < 4; i++) {
420  int mvx = pmv[i]->x + (i & 1) * 16;
421  int mvy = pmv[i]->y + (i >> 1) * 16;
422 
423  // FIXME: clipping or padding?
424  if (y + (mvy >> 1) < 0)
425  mvy = 0;
426  if (x + (mvx >> 1) < 0)
427  mvx = 0;
428 
429  src = &previous[(x + (mvx >> 1)) + (y + (mvy >> 1)) * pitch];
430  dst = current;
431 
432  dsp->put_pixels_tab[1][((mvy & 1) << 1) | (mvx & 1)](dst, src, pitch, 8);
433 
434  /* select next block */
435  if (i & 1)
436  current += 8 * (pitch - 1);
437  else
438  current += 8;
439  }
440 
441  return 0;
442 }
443 
444 static int svq1_decode_delta_block(AVCodecContext *avctx, DSPContext *dsp,
445  GetBitContext *bitbuf,
446  uint8_t *current, uint8_t *previous,
447  int pitch, svq1_pmv *motion, int x, int y)
448 {
449  uint32_t block_type;
450  int result = 0;
451 
452  /* get block type */
453  block_type = get_vlc2(bitbuf, svq1_block_type.table, 2, 2);
454 
455  /* reset motion vectors */
456  if (block_type == SVQ1_BLOCK_SKIP || block_type == SVQ1_BLOCK_INTRA) {
457  motion[0].x =
458  motion[0].y =
459  motion[x / 8 + 2].x =
460  motion[x / 8 + 2].y =
461  motion[x / 8 + 3].x =
462  motion[x / 8 + 3].y = 0;
463  }
464 
465  switch (block_type) {
466  case SVQ1_BLOCK_SKIP:
467  svq1_skip_block(current, previous, pitch, x, y);
468  break;
469 
470  case SVQ1_BLOCK_INTER:
471  result = svq1_motion_inter_block(dsp, bitbuf, current, previous,
472  pitch, motion, x, y);
473 
474  if (result != 0) {
475  av_dlog(avctx, "Error in svq1_motion_inter_block %i\n", result);
476  break;
477  }
478  result = svq1_decode_block_non_intra(bitbuf, current, pitch);
479  break;
480 
481  case SVQ1_BLOCK_INTER_4V:
482  result = svq1_motion_inter_4v_block(dsp, bitbuf, current, previous,
483  pitch, motion, x, y);
484 
485  if (result != 0) {
486  av_dlog(avctx, "Error in svq1_motion_inter_4v_block %i\n", result);
487  break;
488  }
489  result = svq1_decode_block_non_intra(bitbuf, current, pitch);
490  break;
491 
492  case SVQ1_BLOCK_INTRA:
493  result = svq1_decode_block_intra(bitbuf, current, pitch);
494  break;
495  }
496 
497  return result;
498 }
499 
500 static void svq1_parse_string(GetBitContext *bitbuf, uint8_t *out)
501 {
502  uint8_t seed;
503  int i;
504 
505  out[0] = get_bits(bitbuf, 8);
506  seed = string_table[out[0]];
507 
508  for (i = 1; i <= out[0]; i++) {
509  out[i] = get_bits(bitbuf, 8) ^ seed;
510  seed = string_table[out[i] ^ seed];
511  }
512 }
513 
514 static int svq1_decode_frame_header(AVCodecContext *avctx, AVFrame *frame)
515 {
516  SVQ1Context *s = avctx->priv_data;
517  GetBitContext *bitbuf = &s->gb;
518  int frame_size_code;
519  int width = s->width;
520  int height = s->height;
521 
522  skip_bits(bitbuf, 8); /* temporal_reference */
523 
524  /* frame type */
525  s->nonref = 0;
526  switch (get_bits(bitbuf, 2)) {
527  case 0:
528  frame->pict_type = AV_PICTURE_TYPE_I;
529  break;
530  case 2:
531  s->nonref = 1;
532  case 1:
533  frame->pict_type = AV_PICTURE_TYPE_P;
534  break;
535  default:
536  av_log(avctx, AV_LOG_ERROR, "Invalid frame type.\n");
537  return AVERROR_INVALIDDATA;
538  }
539 
540  if (frame->pict_type == AV_PICTURE_TYPE_I) {
541  /* unknown fields */
542  if (s->frame_code == 0x50 || s->frame_code == 0x60) {
543  int csum = get_bits(bitbuf, 16);
544 
545  csum = ff_svq1_packet_checksum(bitbuf->buffer,
546  bitbuf->size_in_bits >> 3,
547  csum);
548 
549  av_dlog(avctx, "%s checksum (%02x) for packet data\n",
550  (csum == 0) ? "correct" : "incorrect", csum);
551  }
552 
553  if ((s->frame_code ^ 0x10) >= 0x50) {
554  uint8_t msg[256];
555 
556  svq1_parse_string(bitbuf, msg);
557 
558  av_log(avctx, AV_LOG_INFO,
559  "embedded message: \"%s\"\n", (char *)msg);
560  }
561 
562  skip_bits(bitbuf, 2);
563  skip_bits(bitbuf, 2);
564  skip_bits1(bitbuf);
565 
566  /* load frame size */
567  frame_size_code = get_bits(bitbuf, 3);
568 
569  if (frame_size_code == 7) {
570  /* load width, height (12 bits each) */
571  width = get_bits(bitbuf, 12);
572  height = get_bits(bitbuf, 12);
573 
574  if (!width || !height)
575  return AVERROR_INVALIDDATA;
576  } else {
577  /* get width, height from table */
578  width = ff_svq1_frame_size_table[frame_size_code][0];
579  height = ff_svq1_frame_size_table[frame_size_code][1];
580  }
581  }
582 
583  /* unknown fields */
584  if (get_bits1(bitbuf)) {
585  skip_bits1(bitbuf); /* use packet checksum if (1) */
586  skip_bits1(bitbuf); /* component checksums after image data if (1) */
587 
588  if (get_bits(bitbuf, 2) != 0)
589  return AVERROR_INVALIDDATA;
590  }
591 
592  if (get_bits1(bitbuf)) {
593  skip_bits1(bitbuf);
594  skip_bits(bitbuf, 4);
595  skip_bits1(bitbuf);
596  skip_bits(bitbuf, 2);
597 
598  while (get_bits1(bitbuf))
599  skip_bits(bitbuf, 8);
600  }
601 
602  s->width = width;
603  s->height = height;
604  return 0;
605 }
606 
607 static int svq1_decode_frame(AVCodecContext *avctx, void *data,
608  int *got_frame, AVPacket *avpkt)
609 {
610  const uint8_t *buf = avpkt->data;
611  int buf_size = avpkt->size;
612  SVQ1Context *s = avctx->priv_data;
613  AVFrame *cur = s->cur;
614  uint8_t *current;
615  int result, i, x, y, width, height;
616  svq1_pmv *pmv;
617 
618  if (cur->data[0])
619  avctx->release_buffer(avctx, cur);
620 
621  /* initialize bit buffer */
622  init_get_bits(&s->gb, buf, buf_size * 8);
623 
624  /* decode frame header */
625  s->frame_code = get_bits(&s->gb, 22);
626 
627  if ((s->frame_code & ~0x70) || !(s->frame_code & 0x60))
628  return AVERROR_INVALIDDATA;
629 
630  /* swap some header bytes (why?) */
631  if (s->frame_code != 0x20) {
632  uint32_t *src = (uint32_t *)(buf + 4);
633 
634  if (buf_size < 36)
635  return AVERROR_INVALIDDATA;
636 
637  for (i = 0; i < 4; i++)
638  src[i] = ((src[i] << 16) | (src[i] >> 16)) ^ src[7 - i];
639  }
640 
641  result = svq1_decode_frame_header(avctx, cur);
642  if (result != 0) {
643  av_dlog(avctx, "Error in svq1_decode_frame_header %i\n", result);
644  return result;
645  }
646  avcodec_set_dimensions(avctx, s->width, s->height);
647 
648  if ((avctx->skip_frame >= AVDISCARD_NONREF && s->nonref) ||
649  (avctx->skip_frame >= AVDISCARD_NONKEY &&
650  cur->pict_type != AV_PICTURE_TYPE_I) ||
651  avctx->skip_frame >= AVDISCARD_ALL)
652  return buf_size;
653 
654  result = ff_get_buffer(avctx, cur);
655  if (result < 0)
656  return result;
657 
658  pmv = av_malloc((FFALIGN(s->width, 16) / 8 + 3) * sizeof(*pmv));
659  if (!pmv)
660  return AVERROR(ENOMEM);
661 
662  /* decode y, u and v components */
663  for (i = 0; i < 3; i++) {
664  int linesize = cur->linesize[i];
665  if (i == 0) {
666  width = FFALIGN(s->width, 16);
667  height = FFALIGN(s->height, 16);
668  } else {
669  if (avctx->flags & CODEC_FLAG_GRAY)
670  break;
671  width = FFALIGN(s->width / 4, 16);
672  height = FFALIGN(s->height / 4, 16);
673  }
674 
675  current = cur->data[i];
676 
677  if (cur->pict_type == AV_PICTURE_TYPE_I) {
678  /* keyframe */
679  for (y = 0; y < height; y += 16) {
680  for (x = 0; x < width; x += 16) {
681  result = svq1_decode_block_intra(&s->gb, &current[x],
682  linesize);
683  if (result) {
684  av_log(avctx, AV_LOG_ERROR,
685  "Error in svq1_decode_block %i (keyframe)\n",
686  result);
687  goto err;
688  }
689  }
690  current += 16 * linesize;
691  }
692  } else {
693  /* delta frame */
694  uint8_t *previous = s->prev->data[i];
695  if (!previous || s->prev->width != s->cur->width || s->prev->height != s->cur->height) {
696  av_log(avctx, AV_LOG_ERROR, "Missing reference frame.\n");
697  result = AVERROR_INVALIDDATA;
698  goto err;
699  }
700 
701  memset(pmv, 0, ((width / 8) + 3) * sizeof(svq1_pmv));
702 
703  for (y = 0; y < height; y += 16) {
704  for (x = 0; x < width; x += 16) {
705  result = svq1_decode_delta_block(avctx, &s->dsp,
706  &s->gb, &current[x],
707  previous, linesize,
708  pmv, x, y);
709  if (result) {
710  av_dlog(avctx,
711  "Error in svq1_decode_delta_block %i\n",
712  result);
713  goto err;
714  }
715  }
716 
717  pmv[0].x =
718  pmv[0].y = 0;
719 
720  current += 16 * linesize;
721  }
722  }
723  }
724 
725  *(AVFrame*)data = *cur;
726  cur->qscale_table = NULL;
727  if (!s->nonref)
728  FFSWAP(AVFrame*, s->cur, s->prev);
729 
730  *got_frame = 1;
731  result = buf_size;
732 
733 err:
734  av_free(pmv);
735  return result;
736 }
737 
738 static av_cold int svq1_decode_init(AVCodecContext *avctx)
739 {
740  SVQ1Context *s = avctx->priv_data;
741  int i;
742  int offset = 0;
743 
744  s->cur = avcodec_alloc_frame();
745  s->prev = avcodec_alloc_frame();
746  if (!s->cur || !s->prev) {
747  avcodec_free_frame(&s->cur);
748  avcodec_free_frame(&s->prev);
749  return AVERROR(ENOMEM);
750  }
751 
752  s->width = avctx->width + 3 & ~3;
753  s->height = avctx->height + 3 & ~3;
754  avctx->pix_fmt = AV_PIX_FMT_YUV410P;
755 
756  ff_dsputil_init(&s->dsp, avctx);
757 
758  INIT_VLC_STATIC(&svq1_block_type, 2, 4,
759  &ff_svq1_block_type_vlc[0][1], 2, 1,
760  &ff_svq1_block_type_vlc[0][0], 2, 1, 6);
761 
762  INIT_VLC_STATIC(&svq1_motion_component, 7, 33,
763  &ff_mvtab[0][1], 2, 1,
764  &ff_mvtab[0][0], 2, 1, 176);
765 
766  for (i = 0; i < 6; i++) {
767  static const uint8_t sizes[2][6] = { { 14, 10, 14, 18, 16, 18 },
768  { 10, 10, 14, 14, 14, 16 } };
769  static VLC_TYPE table[168][2];
770  svq1_intra_multistage[i].table = &table[offset];
771  svq1_intra_multistage[i].table_allocated = sizes[0][i];
772  offset += sizes[0][i];
773  init_vlc(&svq1_intra_multistage[i], 3, 8,
774  &ff_svq1_intra_multistage_vlc[i][0][1], 2, 1,
775  &ff_svq1_intra_multistage_vlc[i][0][0], 2, 1,
776  INIT_VLC_USE_NEW_STATIC);
777  svq1_inter_multistage[i].table = &table[offset];
778  svq1_inter_multistage[i].table_allocated = sizes[1][i];
779  offset += sizes[1][i];
780  init_vlc(&svq1_inter_multistage[i], 3, 8,
781  &ff_svq1_inter_multistage_vlc[i][0][1], 2, 1,
782  &ff_svq1_inter_multistage_vlc[i][0][0], 2, 1,
783  INIT_VLC_USE_NEW_STATIC);
784  }
785 
786  INIT_VLC_STATIC(&svq1_intra_mean, 8, 256,
787  &ff_svq1_intra_mean_vlc[0][1], 4, 2,
788  &ff_svq1_intra_mean_vlc[0][0], 4, 2, 632);
789 
790  INIT_VLC_STATIC(&svq1_inter_mean, 9, 512,
791  &ff_svq1_inter_mean_vlc[0][1], 4, 2,
792  &ff_svq1_inter_mean_vlc[0][0], 4, 2, 1434);
793 
794  return 0;
795 }
796 
797 static av_cold int svq1_decode_end(AVCodecContext *avctx)
798 {
799  SVQ1Context *s = avctx->priv_data;
800 
801  if (s->cur->data[0])
802  avctx->release_buffer(avctx, s->cur);
803  if (s->prev->data[0])
804  avctx->release_buffer(avctx, s->prev);
805  avcodec_free_frame(&s->cur);
806  avcodec_free_frame(&s->prev);
807 
808  return 0;
809 }
810 
811 static void svq1_flush(AVCodecContext *avctx)
812 {
813  SVQ1Context *s = avctx->priv_data;
814 
815  if (s->cur->data[0])
816  avctx->release_buffer(avctx, s->cur);
817  if (s->prev->data[0])
818  avctx->release_buffer(avctx, s->prev);
819 }
820 
821 AVCodec ff_svq1_decoder = {
822  .name = "svq1",
823  .type = AVMEDIA_TYPE_VIDEO,
824  .id = AV_CODEC_ID_SVQ1,
825  .priv_data_size = sizeof(SVQ1Context),
826  .init = svq1_decode_init,
827  .close = svq1_decode_end,
828  .decode = svq1_decode_frame,
829  .capabilities = CODEC_CAP_DR1,
830  .flush = svq1_flush,
831  .pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_YUV410P,
832  AV_PIX_FMT_NONE },
833  .long_name = NULL_IF_CONFIG_SMALL("Sorenson Vector Quantizer 1 / Sorenson Video 1 / SVQ1"),
834 };
Generated on Sat May 25 2013 04:01:11 for FFmpeg by   doxygen 1.8.2