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msmpeg4dec.c
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1 /*
2  * MSMPEG4 backend for encoder and decoder
3  * Copyright (c) 2001 Fabrice Bellard
4  * Copyright (c) 2002-2013 Michael Niedermayer <michaelni@gmx.at>
5  *
6  * msmpeg4v1 & v2 stuff by Michael Niedermayer <michaelni@gmx.at>
7  *
8  * This file is part of FFmpeg.
9  *
10  * FFmpeg is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU Lesser General Public
12  * License as published by the Free Software Foundation; either
13  * version 2.1 of the License, or (at your option) any later version.
14  *
15  * FFmpeg is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18  * Lesser General Public License for more details.
19  *
20  * You should have received a copy of the GNU Lesser General Public
21  * License along with FFmpeg; if not, write to the Free Software
22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23  */
24 
25 #include "avcodec.h"
26 #include "dsputil.h"
27 #include "mpegvideo.h"
28 #include "msmpeg4.h"
29 #include "libavutil/imgutils.h"
30 #include "libavutil/x86/asm.h"
31 #include "h263.h"
32 #include "mpeg4video.h"
33 #include "msmpeg4data.h"
34 #include "vc1data.h"
35 
36 #define DC_VLC_BITS 9
37 #define V2_INTRA_CBPC_VLC_BITS 3
38 #define V2_MB_TYPE_VLC_BITS 7
39 #define MV_VLC_BITS 9
40 #define V2_MV_VLC_BITS 9
41 #define TEX_VLC_BITS 9
42 
43 #define DEFAULT_INTER_INDEX 3
44 
45 static inline int msmpeg4v1_pred_dc(MpegEncContext * s, int n,
46  int32_t **dc_val_ptr)
47 {
48  int i;
49 
50  if (n < 4) {
51  i= 0;
52  } else {
53  i= n-3;
54  }
55 
56  *dc_val_ptr= &s->last_dc[i];
57  return s->last_dc[i];
58 }
59 
60 /****************************************/
61 /* decoding stuff */
62 
63 VLC ff_mb_non_intra_vlc[4];
64 static VLC v2_dc_lum_vlc;
65 static VLC v2_dc_chroma_vlc;
66 static VLC v2_intra_cbpc_vlc;
67 static VLC v2_mb_type_vlc;
68 static VLC v2_mv_vlc;
69 VLC ff_inter_intra_vlc;
70 
71 /* This is identical to h263 except that its range is multiplied by 2. */
72 static int msmpeg4v2_decode_motion(MpegEncContext * s, int pred, int f_code)
73 {
74  int code, val, sign, shift;
75 
76  code = get_vlc2(&s->gb, v2_mv_vlc.table, V2_MV_VLC_BITS, 2);
77  av_dlog(s, "MV code %d at %d %d pred: %d\n", code, s->mb_x,s->mb_y, pred);
78  if (code < 0)
79  return 0xffff;
80 
81  if (code == 0)
82  return pred;
83  sign = get_bits1(&s->gb);
84  shift = f_code - 1;
85  val = code;
86  if (shift) {
87  val = (val - 1) << shift;
88  val |= get_bits(&s->gb, shift);
89  val++;
90  }
91  if (sign)
92  val = -val;
93 
94  val += pred;
95  if (val <= -64)
96  val += 64;
97  else if (val >= 64)
98  val -= 64;
99 
100  return val;
101 }
102 
103 static int msmpeg4v12_decode_mb(MpegEncContext *s, int16_t block[6][64])
104 {
105  int cbp, code, i;
106  uint32_t * const mb_type_ptr = &s->current_picture.mb_type[s->mb_x + s->mb_y*s->mb_stride];
107 
108  if (s->pict_type == AV_PICTURE_TYPE_P) {
109  if (s->use_skip_mb_code) {
110  if (get_bits1(&s->gb)) {
111  /* skip mb */
112  s->mb_intra = 0;
113  for(i=0;i<6;i++)
114  s->block_last_index[i] = -1;
115  s->mv_dir = MV_DIR_FORWARD;
116  s->mv_type = MV_TYPE_16X16;
117  s->mv[0][0][0] = 0;
118  s->mv[0][0][1] = 0;
119  s->mb_skipped = 1;
120  *mb_type_ptr = MB_TYPE_SKIP | MB_TYPE_L0 | MB_TYPE_16x16;
121  return 0;
122  }
123  }
124 
125  if(s->msmpeg4_version==2)
126  code = get_vlc2(&s->gb, v2_mb_type_vlc.table, V2_MB_TYPE_VLC_BITS, 1);
127  else
128  code = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
129  if(code<0 || code>7){
130  av_log(s->avctx, AV_LOG_ERROR, "cbpc %d invalid at %d %d\n", code, s->mb_x, s->mb_y);
131  return -1;
132  }
133 
134  s->mb_intra = code >>2;
135 
136  cbp = code & 0x3;
137  } else {
138  s->mb_intra = 1;
139  if(s->msmpeg4_version==2)
140  cbp= get_vlc2(&s->gb, v2_intra_cbpc_vlc.table, V2_INTRA_CBPC_VLC_BITS, 1);
141  else
142  cbp= get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 1);
143  if(cbp<0 || cbp>3){
144  av_log(s->avctx, AV_LOG_ERROR, "cbpc %d invalid at %d %d\n", cbp, s->mb_x, s->mb_y);
145  return -1;
146  }
147  }
148 
149  if (!s->mb_intra) {
150  int mx, my, cbpy;
151 
152  cbpy= get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
153  if(cbpy<0){
154  av_log(s->avctx, AV_LOG_ERROR, "cbpy %d invalid at %d %d\n", cbp, s->mb_x, s->mb_y);
155  return -1;
156  }
157 
158  cbp|= cbpy<<2;
159  if(s->msmpeg4_version==1 || (cbp&3) != 3) cbp^= 0x3C;
160 
161  ff_h263_pred_motion(s, 0, 0, &mx, &my);
162  mx= msmpeg4v2_decode_motion(s, mx, 1);
163  my= msmpeg4v2_decode_motion(s, my, 1);
164 
165  s->mv_dir = MV_DIR_FORWARD;
166  s->mv_type = MV_TYPE_16X16;
167  s->mv[0][0][0] = mx;
168  s->mv[0][0][1] = my;
169  *mb_type_ptr = MB_TYPE_L0 | MB_TYPE_16x16;
170  } else {
171  if(s->msmpeg4_version==2){
172  s->ac_pred = get_bits1(&s->gb);
173  cbp|= get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1)<<2; //FIXME check errors
174  } else{
175  s->ac_pred = 0;
176  cbp|= get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1)<<2; //FIXME check errors
177  if(s->pict_type==AV_PICTURE_TYPE_P) cbp^=0x3C;
178  }
179  *mb_type_ptr = MB_TYPE_INTRA;
180  }
181 
182  s->dsp.clear_blocks(s->block[0]);
183  for (i = 0; i < 6; i++) {
184  if (ff_msmpeg4_decode_block(s, block[i], i, (cbp >> (5 - i)) & 1, NULL) < 0)
185  {
186  av_log(s->avctx, AV_LOG_ERROR, "\nerror while decoding block: %d x %d (%d)\n", s->mb_x, s->mb_y, i);
187  return -1;
188  }
189  }
190  return 0;
191 }
192 
193 static int msmpeg4v34_decode_mb(MpegEncContext *s, int16_t block[6][64])
194 {
195  int cbp, code, i;
196  uint8_t *coded_val;
197  uint32_t * const mb_type_ptr = &s->current_picture.mb_type[s->mb_x + s->mb_y*s->mb_stride];
198 
199  if (s->pict_type == AV_PICTURE_TYPE_P) {
200  if (s->use_skip_mb_code) {
201  if (get_bits1(&s->gb)) {
202  /* skip mb */
203  s->mb_intra = 0;
204  for(i=0;i<6;i++)
205  s->block_last_index[i] = -1;
206  s->mv_dir = MV_DIR_FORWARD;
207  s->mv_type = MV_TYPE_16X16;
208  s->mv[0][0][0] = 0;
209  s->mv[0][0][1] = 0;
210  s->mb_skipped = 1;
211  *mb_type_ptr = MB_TYPE_SKIP | MB_TYPE_L0 | MB_TYPE_16x16;
212 
213  return 0;
214  }
215  }
216 
217  code = get_vlc2(&s->gb, ff_mb_non_intra_vlc[DEFAULT_INTER_INDEX].table, MB_NON_INTRA_VLC_BITS, 3);
218  if (code < 0)
219  return -1;
220  //s->mb_intra = (code & 0x40) ? 0 : 1;
221  s->mb_intra = (~code & 0x40) >> 6;
222 
223  cbp = code & 0x3f;
224  } else {
225  s->mb_intra = 1;
226  code = get_vlc2(&s->gb, ff_msmp4_mb_i_vlc.table, MB_INTRA_VLC_BITS, 2);
227  if (code < 0)
228  return -1;
229  /* predict coded block pattern */
230  cbp = 0;
231  for(i=0;i<6;i++) {
232  int val = ((code >> (5 - i)) & 1);
233  if (i < 4) {
234  int pred = ff_msmpeg4_coded_block_pred(s, i, &coded_val);
235  val = val ^ pred;
236  *coded_val = val;
237  }
238  cbp |= val << (5 - i);
239  }
240  }
241 
242  if (!s->mb_intra) {
243  int mx, my;
244  if(s->per_mb_rl_table && cbp){
245  s->rl_table_index = decode012(&s->gb);
246  s->rl_chroma_table_index = s->rl_table_index;
247  }
248  ff_h263_pred_motion(s, 0, 0, &mx, &my);
249  if (ff_msmpeg4_decode_motion(s, &mx, &my) < 0)
250  return -1;
251  s->mv_dir = MV_DIR_FORWARD;
252  s->mv_type = MV_TYPE_16X16;
253  s->mv[0][0][0] = mx;
254  s->mv[0][0][1] = my;
255  *mb_type_ptr = MB_TYPE_L0 | MB_TYPE_16x16;
256  } else {
257  av_dlog(s, "I at %d %d %d %06X\n", s->mb_x, s->mb_y,
258  ((cbp & 3) ? 1 : 0) +((cbp & 0x3C)? 2 : 0),
259  show_bits(&s->gb, 24));
260  s->ac_pred = get_bits1(&s->gb);
261  *mb_type_ptr = MB_TYPE_INTRA;
262  if(s->inter_intra_pred){
263  s->h263_aic_dir= get_vlc2(&s->gb, ff_inter_intra_vlc.table, INTER_INTRA_VLC_BITS, 1);
264  av_dlog(s, "%d%d %d %d/",
265  s->ac_pred, s->h263_aic_dir, s->mb_x, s->mb_y);
266  }
267  if(s->per_mb_rl_table && cbp){
268  s->rl_table_index = decode012(&s->gb);
269  s->rl_chroma_table_index = s->rl_table_index;
270  }
271  }
272 
273  s->dsp.clear_blocks(s->block[0]);
274  for (i = 0; i < 6; i++) {
275  if (ff_msmpeg4_decode_block(s, block[i], i, (cbp >> (5 - i)) & 1, NULL) < 0)
276  {
277  av_log(s->avctx, AV_LOG_ERROR, "\nerror while decoding block: %d x %d (%d)\n", s->mb_x, s->mb_y, i);
278  return -1;
279  }
280  }
281 
282  return 0;
283 }
284 
285 /* init all vlc decoding tables */
286 av_cold int ff_msmpeg4_decode_init(AVCodecContext *avctx)
287 {
288  MpegEncContext *s = avctx->priv_data;
289  static volatile int done = 0;
290  int i, ret;
291  MVTable *mv;
292 
293  if ((ret = av_image_check_size(avctx->width, avctx->height, 0, avctx)) < 0)
294  return ret;
295 
296  if (ff_h263_decode_init(avctx) < 0)
297  return -1;
298 
299  ff_msmpeg4_common_init(s);
300 
301  if (!done) {
302  for(i=0;i<NB_RL_TABLES;i++) {
303  ff_init_rl(&ff_rl_table[i], ff_static_rl_table_store[i]);
304  }
305  INIT_VLC_RL(ff_rl_table[0], 642);
306  INIT_VLC_RL(ff_rl_table[1], 1104);
307  INIT_VLC_RL(ff_rl_table[2], 554);
308  INIT_VLC_RL(ff_rl_table[3], 940);
309  INIT_VLC_RL(ff_rl_table[4], 962);
310  INIT_VLC_RL(ff_rl_table[5], 554);
311 
312  mv = &ff_mv_tables[0];
313  INIT_VLC_STATIC(&mv->vlc, MV_VLC_BITS, mv->n + 1,
314  mv->table_mv_bits, 1, 1,
315  mv->table_mv_code, 2, 2, 3714);
316  mv = &ff_mv_tables[1];
317  INIT_VLC_STATIC(&mv->vlc, MV_VLC_BITS, mv->n + 1,
318  mv->table_mv_bits, 1, 1,
319  mv->table_mv_code, 2, 2, 2694);
320 
321  INIT_VLC_STATIC(&ff_msmp4_dc_luma_vlc[0], DC_VLC_BITS, 120,
322  &ff_table0_dc_lum[0][1], 8, 4,
323  &ff_table0_dc_lum[0][0], 8, 4, 1158);
324  INIT_VLC_STATIC(&ff_msmp4_dc_chroma_vlc[0], DC_VLC_BITS, 120,
325  &ff_table0_dc_chroma[0][1], 8, 4,
326  &ff_table0_dc_chroma[0][0], 8, 4, 1118);
327  INIT_VLC_STATIC(&ff_msmp4_dc_luma_vlc[1], DC_VLC_BITS, 120,
328  &ff_table1_dc_lum[0][1], 8, 4,
329  &ff_table1_dc_lum[0][0], 8, 4, 1476);
330  INIT_VLC_STATIC(&ff_msmp4_dc_chroma_vlc[1], DC_VLC_BITS, 120,
331  &ff_table1_dc_chroma[0][1], 8, 4,
332  &ff_table1_dc_chroma[0][0], 8, 4, 1216);
333 
334  INIT_VLC_STATIC(&v2_dc_lum_vlc, DC_VLC_BITS, 512,
335  &ff_v2_dc_lum_table[0][1], 8, 4,
336  &ff_v2_dc_lum_table[0][0], 8, 4, 1472);
337  INIT_VLC_STATIC(&v2_dc_chroma_vlc, DC_VLC_BITS, 512,
338  &ff_v2_dc_chroma_table[0][1], 8, 4,
339  &ff_v2_dc_chroma_table[0][0], 8, 4, 1506);
340 
341  INIT_VLC_STATIC(&v2_intra_cbpc_vlc, V2_INTRA_CBPC_VLC_BITS, 4,
342  &ff_v2_intra_cbpc[0][1], 2, 1,
343  &ff_v2_intra_cbpc[0][0], 2, 1, 8);
344  INIT_VLC_STATIC(&v2_mb_type_vlc, V2_MB_TYPE_VLC_BITS, 8,
345  &ff_v2_mb_type[0][1], 2, 1,
346  &ff_v2_mb_type[0][0], 2, 1, 128);
347  INIT_VLC_STATIC(&v2_mv_vlc, V2_MV_VLC_BITS, 33,
348  &ff_mvtab[0][1], 2, 1,
349  &ff_mvtab[0][0], 2, 1, 538);
350 
351  INIT_VLC_STATIC(&ff_mb_non_intra_vlc[0], MB_NON_INTRA_VLC_BITS, 128,
352  &ff_wmv2_inter_table[0][0][1], 8, 4,
353  &ff_wmv2_inter_table[0][0][0], 8, 4, 1636);
354  INIT_VLC_STATIC(&ff_mb_non_intra_vlc[1], MB_NON_INTRA_VLC_BITS, 128,
355  &ff_wmv2_inter_table[1][0][1], 8, 4,
356  &ff_wmv2_inter_table[1][0][0], 8, 4, 2648);
357  INIT_VLC_STATIC(&ff_mb_non_intra_vlc[2], MB_NON_INTRA_VLC_BITS, 128,
358  &ff_wmv2_inter_table[2][0][1], 8, 4,
359  &ff_wmv2_inter_table[2][0][0], 8, 4, 1532);
360  INIT_VLC_STATIC(&ff_mb_non_intra_vlc[3], MB_NON_INTRA_VLC_BITS, 128,
361  &ff_wmv2_inter_table[3][0][1], 8, 4,
362  &ff_wmv2_inter_table[3][0][0], 8, 4, 2488);
363 
364  INIT_VLC_STATIC(&ff_msmp4_mb_i_vlc, MB_INTRA_VLC_BITS, 64,
365  &ff_msmp4_mb_i_table[0][1], 4, 2,
366  &ff_msmp4_mb_i_table[0][0], 4, 2, 536);
367 
368  INIT_VLC_STATIC(&ff_inter_intra_vlc, INTER_INTRA_VLC_BITS, 4,
369  &ff_table_inter_intra[0][1], 2, 1,
370  &ff_table_inter_intra[0][0], 2, 1, 8);
371  done = 1;
372  }
373 
374  switch(s->msmpeg4_version){
375  case 1:
376  case 2:
377  s->decode_mb= msmpeg4v12_decode_mb;
378  break;
379  case 3:
380  case 4:
381  s->decode_mb= msmpeg4v34_decode_mb;
382  break;
383  case 5:
384  if (CONFIG_WMV2_DECODER)
385  s->decode_mb= ff_wmv2_decode_mb;
386  case 6:
387  //FIXME + TODO VC1 decode mb
388  break;
389  }
390 
391  s->slice_height= s->mb_height; //to avoid 1/0 if the first frame is not a keyframe
392 
393  return 0;
394 }
395 
396 int ff_msmpeg4_decode_picture_header(MpegEncContext * s)
397 {
398  int code;
399 
400  if(s->msmpeg4_version==1){
401  int start_code = get_bits_long(&s->gb, 32);
402  if(start_code!=0x00000100){
403  av_log(s->avctx, AV_LOG_ERROR, "invalid startcode\n");
404  return -1;
405  }
406 
407  skip_bits(&s->gb, 5); // frame number */
408  }
409 
410  s->pict_type = get_bits(&s->gb, 2) + 1;
411  if (s->pict_type != AV_PICTURE_TYPE_I &&
412  s->pict_type != AV_PICTURE_TYPE_P){
413  av_log(s->avctx, AV_LOG_ERROR, "invalid picture type\n");
414  return -1;
415  }
416 #if 0
417 {
418  static int had_i=0;
419  if(s->pict_type == AV_PICTURE_TYPE_I) had_i=1;
420  if(!had_i) return -1;
421 }
422 #endif
423  s->chroma_qscale= s->qscale = get_bits(&s->gb, 5);
424  if(s->qscale==0){
425  av_log(s->avctx, AV_LOG_ERROR, "invalid qscale\n");
426  return -1;
427  }
428 
429  if (s->pict_type == AV_PICTURE_TYPE_I) {
430  code = get_bits(&s->gb, 5);
431  if(s->msmpeg4_version==1){
432  if(code==0 || code>s->mb_height){
433  av_log(s->avctx, AV_LOG_ERROR, "invalid slice height %d\n", code);
434  return -1;
435  }
436 
437  s->slice_height = code;
438  }else{
439  /* 0x17: one slice, 0x18: two slices, ... */
440  if (code < 0x17){
441  av_log(s->avctx, AV_LOG_ERROR, "error, slice code was %X\n", code);
442  return -1;
443  }
444 
445  s->slice_height = s->mb_height / (code - 0x16);
446  }
447 
448  switch(s->msmpeg4_version){
449  case 1:
450  case 2:
451  s->rl_chroma_table_index = 2;
452  s->rl_table_index = 2;
453 
454  s->dc_table_index = 0; //not used
455  break;
456  case 3:
457  s->rl_chroma_table_index = decode012(&s->gb);
458  s->rl_table_index = decode012(&s->gb);
459 
460  s->dc_table_index = get_bits1(&s->gb);
461  break;
462  case 4:
463  ff_msmpeg4_decode_ext_header(s, (2+5+5+17+7)/8);
464 
465  if(s->bit_rate > MBAC_BITRATE) s->per_mb_rl_table= get_bits1(&s->gb);
466  else s->per_mb_rl_table= 0;
467 
468  if(!s->per_mb_rl_table){
469  s->rl_chroma_table_index = decode012(&s->gb);
470  s->rl_table_index = decode012(&s->gb);
471  }
472 
473  s->dc_table_index = get_bits1(&s->gb);
474  s->inter_intra_pred= 0;
475  break;
476  }
477  s->no_rounding = 1;
478  if(s->avctx->debug&FF_DEBUG_PICT_INFO)
479  av_log(s->avctx, AV_LOG_DEBUG, "qscale:%d rlc:%d rl:%d dc:%d mbrl:%d slice:%d \n",
480  s->qscale,
481  s->rl_chroma_table_index,
482  s->rl_table_index,
483  s->dc_table_index,
484  s->per_mb_rl_table,
485  s->slice_height);
486  } else {
487  switch(s->msmpeg4_version){
488  case 1:
489  case 2:
490  if(s->msmpeg4_version==1)
491  s->use_skip_mb_code = 1;
492  else
493  s->use_skip_mb_code = get_bits1(&s->gb);
494  s->rl_table_index = 2;
495  s->rl_chroma_table_index = s->rl_table_index;
496  s->dc_table_index = 0; //not used
497  s->mv_table_index = 0;
498  break;
499  case 3:
500  s->use_skip_mb_code = get_bits1(&s->gb);
501  s->rl_table_index = decode012(&s->gb);
502  s->rl_chroma_table_index = s->rl_table_index;
503 
504  s->dc_table_index = get_bits1(&s->gb);
505 
506  s->mv_table_index = get_bits1(&s->gb);
507  break;
508  case 4:
509  s->use_skip_mb_code = get_bits1(&s->gb);
510 
511  if(s->bit_rate > MBAC_BITRATE) s->per_mb_rl_table= get_bits1(&s->gb);
512  else s->per_mb_rl_table= 0;
513 
514  if(!s->per_mb_rl_table){
515  s->rl_table_index = decode012(&s->gb);
516  s->rl_chroma_table_index = s->rl_table_index;
517  }
518 
519  s->dc_table_index = get_bits1(&s->gb);
520 
521  s->mv_table_index = get_bits1(&s->gb);
522  s->inter_intra_pred= (s->width*s->height < 320*240 && s->bit_rate<=II_BITRATE);
523  break;
524  }
525 
526  if(s->avctx->debug&FF_DEBUG_PICT_INFO)
527  av_log(s->avctx, AV_LOG_DEBUG, "skip:%d rl:%d rlc:%d dc:%d mv:%d mbrl:%d qp:%d \n",
528  s->use_skip_mb_code,
529  s->rl_table_index,
530  s->rl_chroma_table_index,
531  s->dc_table_index,
532  s->mv_table_index,
533  s->per_mb_rl_table,
534  s->qscale);
535 
536  if(s->flipflop_rounding){
537  s->no_rounding ^= 1;
538  }else{
539  s->no_rounding = 0;
540  }
541  }
542  av_dlog(s->avctx, "%d %d %d %d %d\n", s->pict_type, s->bit_rate,
543  s->inter_intra_pred, s->width, s->height);
544 
545  s->esc3_level_length= 0;
546  s->esc3_run_length= 0;
547 
548  return 0;
549 }
550 
551 int ff_msmpeg4_decode_ext_header(MpegEncContext * s, int buf_size)
552 {
553  int left= buf_size*8 - get_bits_count(&s->gb);
554  int length= s->msmpeg4_version>=3 ? 17 : 16;
555  /* the alt_bitstream reader could read over the end so we need to check it */
556  if(left>=length && left<length+8)
557  {
558  skip_bits(&s->gb, 5); /* fps */
559  s->bit_rate= get_bits(&s->gb, 11)*1024;
560  if(s->msmpeg4_version>=3)
561  s->flipflop_rounding= get_bits1(&s->gb);
562  else
563  s->flipflop_rounding= 0;
564  }
565  else if(left<length+8)
566  {
567  s->flipflop_rounding= 0;
568  if(s->msmpeg4_version != 2)
569  av_log(s->avctx, AV_LOG_ERROR, "ext header missing, %d left\n", left);
570  }
571  else
572  {
573  av_log(s->avctx, AV_LOG_ERROR, "I frame too long, ignoring ext header\n");
574  }
575 
576  return 0;
577 }
578 
579 static int msmpeg4_decode_dc(MpegEncContext * s, int n, int *dir_ptr)
580 {
581  int level, pred;
582 
583  if(s->msmpeg4_version<=2){
584  if (n < 4) {
585  level = get_vlc2(&s->gb, v2_dc_lum_vlc.table, DC_VLC_BITS, 3);
586  } else {
587  level = get_vlc2(&s->gb, v2_dc_chroma_vlc.table, DC_VLC_BITS, 3);
588  }
589  if (level < 0) {
590  av_log(s->avctx, AV_LOG_ERROR, "illegal dc vlc\n");
591  *dir_ptr = 0;
592  return -1;
593  }
594  level-=256;
595  }else{ //FIXME optimize use unified tables & index
596  if (n < 4) {
597  level = get_vlc2(&s->gb, ff_msmp4_dc_luma_vlc[s->dc_table_index].table, DC_VLC_BITS, 3);
598  } else {
599  level = get_vlc2(&s->gb, ff_msmp4_dc_chroma_vlc[s->dc_table_index].table, DC_VLC_BITS, 3);
600  }
601  if (level < 0){
602  av_log(s->avctx, AV_LOG_ERROR, "illegal dc vlc\n");
603  *dir_ptr = 0;
604  return -1;
605  }
606 
607  if (level == DC_MAX) {
608  level = get_bits(&s->gb, 8);
609  if (get_bits1(&s->gb))
610  level = -level;
611  } else if (level != 0) {
612  if (get_bits1(&s->gb))
613  level = -level;
614  }
615  }
616 
617  if(s->msmpeg4_version==1){
618  int32_t *dc_val;
619  pred = msmpeg4v1_pred_dc(s, n, &dc_val);
620  level += pred;
621 
622  /* update predictor */
623  *dc_val= level;
624  }else{
625  int16_t *dc_val;
626  pred = ff_msmpeg4_pred_dc(s, n, &dc_val, dir_ptr);
627  level += pred;
628 
629  /* update predictor */
630  if (n < 4) {
631  *dc_val = level * s->y_dc_scale;
632  } else {
633  *dc_val = level * s->c_dc_scale;
634  }
635  }
636 
637  return level;
638 }
639 
640 //#define ERROR_DETAILS
641 int ff_msmpeg4_decode_block(MpegEncContext * s, int16_t * block,
642  int n, int coded, const uint8_t *scan_table)
643 {
644  int level, i, last, run, run_diff;
645  int av_uninit(dc_pred_dir);
646  RLTable *rl;
647  RL_VLC_ELEM *rl_vlc;
648  int qmul, qadd;
649 
650  if (s->mb_intra) {
651  qmul=1;
652  qadd=0;
653 
654  /* DC coef */
655  level = msmpeg4_decode_dc(s, n, &dc_pred_dir);
656 
657  if (level < 0){
658  av_log(s->avctx, AV_LOG_ERROR, "dc overflow- block: %d qscale: %d//\n", n, s->qscale);
659  if(s->inter_intra_pred) level=0;
660  }
661  if (n < 4) {
662  rl = &ff_rl_table[s->rl_table_index];
663  if(level > 256*s->y_dc_scale){
664  av_log(s->avctx, AV_LOG_ERROR, "dc overflow+ L qscale: %d//\n", s->qscale);
665  if(!s->inter_intra_pred) return -1;
666  }
667  } else {
668  rl = &ff_rl_table[3 + s->rl_chroma_table_index];
669  if(level > 256*s->c_dc_scale){
670  av_log(s->avctx, AV_LOG_ERROR, "dc overflow+ C qscale: %d//\n", s->qscale);
671  if(!s->inter_intra_pred) return -1;
672  }
673  }
674  block[0] = level;
675 
676  run_diff = s->msmpeg4_version >= 4;
677  i = 0;
678  if (!coded) {
679  goto not_coded;
680  }
681  if (s->ac_pred) {
682  if (dc_pred_dir == 0)
683  scan_table = s->intra_v_scantable.permutated; /* left */
684  else
685  scan_table = s->intra_h_scantable.permutated; /* top */
686  } else {
687  scan_table = s->intra_scantable.permutated;
688  }
689  rl_vlc= rl->rl_vlc[0];
690  } else {
691  qmul = s->qscale << 1;
692  qadd = (s->qscale - 1) | 1;
693  i = -1;
694  rl = &ff_rl_table[3 + s->rl_table_index];
695 
696  if(s->msmpeg4_version==2)
697  run_diff = 0;
698  else
699  run_diff = 1;
700 
701  if (!coded) {
702  s->block_last_index[n] = i;
703  return 0;
704  }
705  if(!scan_table)
706  scan_table = s->inter_scantable.permutated;
707  rl_vlc= rl->rl_vlc[s->qscale];
708  }
709  {
710  OPEN_READER(re, &s->gb);
711  for(;;) {
712  UPDATE_CACHE(re, &s->gb);
713  GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 0);
714  if (level==0) {
715  int cache;
716  cache= GET_CACHE(re, &s->gb);
717  /* escape */
718  if (s->msmpeg4_version==1 || (cache&0x80000000)==0) {
719  if (s->msmpeg4_version==1 || (cache&0x40000000)==0) {
720  /* third escape */
721  if(s->msmpeg4_version!=1) LAST_SKIP_BITS(re, &s->gb, 2);
722  UPDATE_CACHE(re, &s->gb);
723  if(s->msmpeg4_version<=3){
724  last= SHOW_UBITS(re, &s->gb, 1); SKIP_CACHE(re, &s->gb, 1);
725  run= SHOW_UBITS(re, &s->gb, 6); SKIP_CACHE(re, &s->gb, 6);
726  level= SHOW_SBITS(re, &s->gb, 8);
727  SKIP_COUNTER(re, &s->gb, 1+6+8);
728  }else{
729  int sign;
730  last= SHOW_UBITS(re, &s->gb, 1); SKIP_BITS(re, &s->gb, 1);
731  if(!s->esc3_level_length){
732  int ll;
733  av_dlog(s->avctx, "ESC-3 %X at %d %d\n",
734  show_bits(&s->gb, 24), s->mb_x, s->mb_y);
735  if(s->qscale<8){
736  ll= SHOW_UBITS(re, &s->gb, 3); SKIP_BITS(re, &s->gb, 3);
737  if(ll==0){
738  ll= 8+SHOW_UBITS(re, &s->gb, 1); SKIP_BITS(re, &s->gb, 1);
739  }
740  }else{
741  ll=2;
742  while(ll<8 && SHOW_UBITS(re, &s->gb, 1)==0){
743  ll++;
744  SKIP_BITS(re, &s->gb, 1);
745  }
746  if(ll<8) SKIP_BITS(re, &s->gb, 1);
747  }
748 
749  s->esc3_level_length= ll;
750  s->esc3_run_length= SHOW_UBITS(re, &s->gb, 2) + 3; SKIP_BITS(re, &s->gb, 2);
751  UPDATE_CACHE(re, &s->gb);
752  }
753  run= SHOW_UBITS(re, &s->gb, s->esc3_run_length);
754  SKIP_BITS(re, &s->gb, s->esc3_run_length);
755 
756  sign= SHOW_UBITS(re, &s->gb, 1);
757  SKIP_BITS(re, &s->gb, 1);
758 
759  level= SHOW_UBITS(re, &s->gb, s->esc3_level_length);
760  SKIP_BITS(re, &s->gb, s->esc3_level_length);
761  if(sign) level= -level;
762  }
763 
764 #if 0 // waste of time / this will detect very few errors
765  {
766  const int abs_level= FFABS(level);
767  const int run1= run - rl->max_run[last][abs_level] - run_diff;
768  if(abs_level<=MAX_LEVEL && run<=MAX_RUN){
769  if(abs_level <= rl->max_level[last][run]){
770  av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, vlc encoding possible\n");
771  return DECODING_AC_LOST;
772  }
773  if(abs_level <= rl->max_level[last][run]*2){
774  av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, esc 1 encoding possible\n");
775  return DECODING_AC_LOST;
776  }
777  if(run1>=0 && abs_level <= rl->max_level[last][run1]){
778  av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, esc 2 encoding possible\n");
779  return DECODING_AC_LOST;
780  }
781  }
782  }
783 #endif
784  //level = level * qmul + (level>0) * qadd - (level<=0) * qadd ;
785  if (level>0) level= level * qmul + qadd;
786  else level= level * qmul - qadd;
787 #if 0 // waste of time too :(
788  if(level>2048 || level<-2048){
789  av_log(s->avctx, AV_LOG_ERROR, "|level| overflow in 3. esc\n");
790  return DECODING_AC_LOST;
791  }
792 #endif
793  i+= run + 1;
794  if(last) i+=192;
795 #ifdef ERROR_DETAILS
796  if(run==66)
797  av_log(s->avctx, AV_LOG_ERROR, "illegal vlc code in ESC3 level=%d\n", level);
798  else if((i>62 && i<192) || i>192+63)
799  av_log(s->avctx, AV_LOG_ERROR, "run overflow in ESC3 i=%d run=%d level=%d\n", i, run, level);
800 #endif
801  } else {
802  /* second escape */
803  SKIP_BITS(re, &s->gb, 2);
804  GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
805  i+= run + rl->max_run[run>>7][level/qmul] + run_diff; //FIXME opt indexing
806  level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
807  LAST_SKIP_BITS(re, &s->gb, 1);
808 #ifdef ERROR_DETAILS
809  if(run==66)
810  av_log(s->avctx, AV_LOG_ERROR, "illegal vlc code in ESC2 level=%d\n", level);
811  else if((i>62 && i<192) || i>192+63)
812  av_log(s->avctx, AV_LOG_ERROR, "run overflow in ESC2 i=%d run=%d level=%d\n", i, run, level);
813 #endif
814  }
815  } else {
816  /* first escape */
817  SKIP_BITS(re, &s->gb, 1);
818  GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
819  i+= run;
820  level = level + rl->max_level[run>>7][(run-1)&63] * qmul;//FIXME opt indexing
821  level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
822  LAST_SKIP_BITS(re, &s->gb, 1);
823 #ifdef ERROR_DETAILS
824  if(run==66)
825  av_log(s->avctx, AV_LOG_ERROR, "illegal vlc code in ESC1 level=%d\n", level);
826  else if((i>62 && i<192) || i>192+63)
827  av_log(s->avctx, AV_LOG_ERROR, "run overflow in ESC1 i=%d run=%d level=%d\n", i, run, level);
828 #endif
829  }
830  } else {
831  i+= run;
832  level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
833  LAST_SKIP_BITS(re, &s->gb, 1);
834 #ifdef ERROR_DETAILS
835  if(run==66)
836  av_log(s->avctx, AV_LOG_ERROR, "illegal vlc code level=%d\n", level);
837  else if((i>62 && i<192) || i>192+63)
838  av_log(s->avctx, AV_LOG_ERROR, "run overflow i=%d run=%d level=%d\n", i, run, level);
839 #endif
840  }
841  if (i > 62){
842  i-= 192;
843  if(i&(~63)){
844  const int left= get_bits_left(&s->gb);
845  if(((i+192 == 64 && level/qmul==-1) || !(s->err_recognition&(AV_EF_BITSTREAM|AV_EF_COMPLIANT))) && left>=0){
846  av_log(s->avctx, AV_LOG_ERROR, "ignoring overflow at %d %d\n", s->mb_x, s->mb_y);
847  i = 63;
848  break;
849  }else{
850  av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
851  return -1;
852  }
853  }
854 
855  block[scan_table[i]] = level;
856  break;
857  }
858 
859  block[scan_table[i]] = level;
860  }
861  CLOSE_READER(re, &s->gb);
862  }
863  not_coded:
864  if (s->mb_intra) {
865  ff_mpeg4_pred_ac(s, block, n, dc_pred_dir);
866  if (s->ac_pred) {
867  i = 63; /* XXX: not optimal */
868  }
869  }
870  if(s->msmpeg4_version>=4 && i>0) i=63; //FIXME/XXX optimize
871  s->block_last_index[n] = i;
872 
873  return 0;
874 }
875 
876 int ff_msmpeg4_decode_motion(MpegEncContext * s,
877  int *mx_ptr, int *my_ptr)
878 {
879  MVTable *mv;
880  int code, mx, my;
881 
882  mv = &ff_mv_tables[s->mv_table_index];
883 
884  code = get_vlc2(&s->gb, mv->vlc.table, MV_VLC_BITS, 2);
885  if (code < 0){
886  av_log(s->avctx, AV_LOG_ERROR, "illegal MV code at %d %d\n", s->mb_x, s->mb_y);
887  return -1;
888  }
889  if (code == mv->n) {
890  mx = get_bits(&s->gb, 6);
891  my = get_bits(&s->gb, 6);
892  } else {
893  mx = mv->table_mvx[code];
894  my = mv->table_mvy[code];
895  }
896 
897  mx += *mx_ptr - 32;
898  my += *my_ptr - 32;
899  /* WARNING : they do not do exactly modulo encoding */
900  if (mx <= -64)
901  mx += 64;
902  else if (mx >= 64)
903  mx -= 64;
904 
905  if (my <= -64)
906  my += 64;
907  else if (my >= 64)
908  my -= 64;
909  *mx_ptr = mx;
910  *my_ptr = my;
911  return 0;
912 }
913 
914 AVCodec ff_msmpeg4v1_decoder = {
915  .name = "msmpeg4v1",
916  .long_name = NULL_IF_CONFIG_SMALL("MPEG-4 part 2 Microsoft variant version 1"),
917  .type = AVMEDIA_TYPE_VIDEO,
918  .id = AV_CODEC_ID_MSMPEG4V1,
919  .priv_data_size = sizeof(MpegEncContext),
920  .init = ff_msmpeg4_decode_init,
921  .close = ff_h263_decode_end,
922  .decode = ff_h263_decode_frame,
923  .capabilities = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
924  .max_lowres = 3,
925  .pix_fmts = ff_pixfmt_list_420,
926 };
927 
928 AVCodec ff_msmpeg4v2_decoder = {
929  .name = "msmpeg4v2",
930  .long_name = NULL_IF_CONFIG_SMALL("MPEG-4 part 2 Microsoft variant version 2"),
931  .type = AVMEDIA_TYPE_VIDEO,
932  .id = AV_CODEC_ID_MSMPEG4V2,
933  .priv_data_size = sizeof(MpegEncContext),
934  .init = ff_msmpeg4_decode_init,
935  .close = ff_h263_decode_end,
936  .decode = ff_h263_decode_frame,
937  .capabilities = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
938  .max_lowres = 3,
939  .pix_fmts = ff_pixfmt_list_420,
940 };
941 
942 AVCodec ff_msmpeg4v3_decoder = {
943  .name = "msmpeg4",
944  .long_name = NULL_IF_CONFIG_SMALL("MPEG-4 part 2 Microsoft variant version 3"),
945  .type = AVMEDIA_TYPE_VIDEO,
946  .id = AV_CODEC_ID_MSMPEG4V3,
947  .priv_data_size = sizeof(MpegEncContext),
948  .init = ff_msmpeg4_decode_init,
949  .close = ff_h263_decode_end,
950  .decode = ff_h263_decode_frame,
951  .capabilities = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
952  .max_lowres = 3,
953  .pix_fmts = ff_pixfmt_list_420,
954 };
955 
956 AVCodec ff_wmv1_decoder = {
957  .name = "wmv1",
958  .long_name = NULL_IF_CONFIG_SMALL("Windows Media Video 7"),
959  .type = AVMEDIA_TYPE_VIDEO,
960  .id = AV_CODEC_ID_WMV1,
961  .priv_data_size = sizeof(MpegEncContext),
962  .init = ff_msmpeg4_decode_init,
963  .close = ff_h263_decode_end,
964  .decode = ff_h263_decode_frame,
965  .capabilities = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
966  .max_lowres = 3,
967  .pix_fmts = ff_pixfmt_list_420,
968 };
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