]> git.sesse.net Git - vlc/blob - src/video_decoder/vpar_headers.c
* Totally rewrote the video decoder (inspired by walken's mpeg2dec), implying :
[vlc] / src / video_decoder / vpar_headers.c
1 /*****************************************************************************
2  * vpar_headers.c : headers parsing
3  *****************************************************************************
4  * Copyright (C) 1999, 2000 VideoLAN
5  * $Id: vpar_headers.c,v 1.7 2001/08/22 17:21:46 massiot Exp $
6  *
7  * Authors: Christophe Massiot <massiot@via.ecp.fr>
8  *          Stéphane Borel <stef@via.ecp.fr>
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation; either version 2 of the License, or
13  * (at your option) any later version.
14  * 
15  * This program 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
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
23  *****************************************************************************/
24
25 /*****************************************************************************
26  * Preamble
27  *****************************************************************************/
28 #include "defs.h"
29
30 #include <stdlib.h>                                                /* free() */
31 #include <string.h>                                    /* memcpy(), memset() */
32
33 #include "config.h"
34 #include "common.h"
35 #include "threads.h"
36 #include "mtime.h"
37
38 #include "intf_msg.h"
39
40 #include "stream_control.h"
41 #include "input_ext-dec.h"
42
43 #include "video.h"
44 #include "video_output.h"
45
46 #include "vdec_ext-plugins.h"
47 #include "vpar_pool.h"
48 #include "video_parser.h"
49
50 /*
51  * Local prototypes
52  */
53 static __inline__ void NextStartCode( bit_stream_t * );
54 static void SequenceHeader( vpar_thread_t * p_vpar );
55 static void GroupHeader( vpar_thread_t * p_vpar );
56 static void PictureHeader( vpar_thread_t * p_vpar );
57 static void ExtensionAndUserData( vpar_thread_t * p_vpar );
58 static void QuantMatrixExtension( vpar_thread_t * p_vpar );
59 static void SequenceScalableExtension( vpar_thread_t * p_vpar );
60 static void SequenceDisplayExtension( vpar_thread_t * p_vpar );
61 static void PictureDisplayExtension( vpar_thread_t * p_vpar );
62 static void PictureSpatialScalableExtension( vpar_thread_t * p_vpar );
63 static void PictureTemporalScalableExtension( vpar_thread_t * p_vpar );
64 static void CopyrightExtension( vpar_thread_t * p_vpar );
65
66 /*
67  * Standard variables
68  */
69
70 /*****************************************************************************
71  * pi_default_intra_quant : default quantization matrix
72  *****************************************************************************/
73 u8 pi_default_intra_quant[] ATTR_ALIGN(16) =
74 {
75     8,  16, 19, 22, 26, 27, 29, 34,
76     16, 16, 22, 24, 27, 29, 34, 37,
77     19, 22, 26, 27, 29, 34, 34, 38,
78     22, 22, 26, 27, 29, 34, 37, 40,
79     22, 26, 27, 29, 32, 35, 40, 48,
80     26, 27, 29, 32, 35, 40, 48, 58,
81     26, 27, 29, 34, 38, 46, 56, 69,
82     27, 29, 35, 38, 46, 56, 69, 83
83 };
84
85 /*****************************************************************************
86  * pi_default_nonintra_quant : default quantization matrix
87  *****************************************************************************/
88 u8 pi_default_nonintra_quant[] ATTR_ALIGN(16) =
89 {
90     16, 16, 16, 16, 16, 16, 16, 16,
91     16, 16, 16, 16, 16, 16, 16, 16,
92     16, 16, 16, 16, 16, 16, 16, 16,
93     16, 16, 16, 16, 16, 16, 16, 16,
94     16, 16, 16, 16, 16, 16, 16, 16,
95     16, 16, 16, 16, 16, 16, 16, 16,
96     16, 16, 16, 16, 16, 16, 16, 16,
97     16, 16, 16, 16, 16, 16, 16, 16
98 };
99
100 /*****************************************************************************
101  * pi_scan : zig-zag and alternate scan patterns
102  *****************************************************************************/
103 u8 pi_scan[2][64] ATTR_ALIGN(16) =
104 {
105     { /* Zig-Zag pattern */
106         0,1,8,16,9,2,3,10,17,24,32,25,18,11,4,5,
107         12,19,26,33,40,48,41,34,27,20,13,6,7,14,21,28,
108         35,42,49,56,57,50,43,36,29,22,15,23,30,37,44,51,
109         58,59,52,45,38,31,39,46,53,60,61,54,47,55,62,63
110     },
111     { /* Alternate scan pattern */
112         0,8,16,24,1,9,2,10,17,25,32,40,48,56,57,49,
113         41,33,26,18,3,11,4,12,19,27,34,42,50,58,35,43,
114         51,59,20,28,5,13,6,14,21,29,36,44,52,60,37,45,
115         53,61,22,30,7,15,23,31,38,46,54,62,39,47,55,63
116     }
117 };
118
119 /*
120  * Local inline functions.
121  */
122
123 /*****************************************************************************
124  * ReferenceUpdate : Update the reference pointers when we have a new picture
125  *****************************************************************************/
126 static void __inline__ ReferenceUpdate( vpar_thread_t * p_vpar,
127                                         int i_coding_type,
128                                         picture_t * p_newref )
129 {
130     if( i_coding_type != B_CODING_TYPE )
131     {
132         if( p_vpar->sequence.p_forward != NULL )
133         {
134             vout_UnlinkPicture( p_vpar->p_vout, p_vpar->sequence.p_forward );
135         }
136         if( p_vpar->sequence.p_backward != NULL )
137         {
138             vout_DatePicture( p_vpar->p_vout, p_vpar->sequence.p_backward,
139                               vpar_SynchroDate( p_vpar ) );
140         }
141         p_vpar->sequence.p_forward = p_vpar->sequence.p_backward;
142         p_vpar->sequence.p_backward = p_newref;
143         if( p_newref != NULL )
144         {
145             vout_LinkPicture( p_vpar->p_vout, p_newref );
146         }
147     }
148     else if( p_newref != NULL )
149     {
150         /* Put date immediately. */
151         vout_DatePicture( p_vpar->p_vout, p_newref, vpar_SynchroDate(p_vpar) );
152     }
153 }
154
155 /*****************************************************************************
156  * ReferenceReplace : Replace the last reference pointer when we destroy
157  *                    a picture
158  *****************************************************************************/
159 static void __inline__ ReferenceReplace( vpar_thread_t * p_vpar,
160                                          int i_coding_type,
161                                          picture_t * p_newref )
162 {
163     if( i_coding_type != B_CODING_TYPE )
164     {
165         if( p_vpar->sequence.p_backward != NULL )
166         {
167             vout_UnlinkPicture( p_vpar->p_vout, p_vpar->sequence.p_backward );
168         }
169         p_vpar->sequence.p_backward = p_newref;
170         if( p_newref != NULL )
171         {
172             vout_LinkPicture( p_vpar->p_vout, p_newref );
173         }
174     }
175 }
176
177 /*****************************************************************************
178  * LoadMatrix : Load a quantization matrix
179  *****************************************************************************/
180 static __inline__ void LoadMatrix( vpar_thread_t * p_vpar,
181                                    quant_matrix_t * p_matrix )
182 {
183     int i_dummy;
184
185     if( !p_matrix->b_allocated )
186     {
187         /* Allocate a piece of memory to load the matrix. */
188         if( (p_matrix->pi_matrix = (u8 *)malloc( 64*sizeof(u8) )) == NULL )
189         {
190             intf_ErrMsg( "vpar error: allocation error in LoadMatrix()" );
191             p_vpar->p_fifo->b_error = 1;
192             return;
193         }
194         p_matrix->b_allocated = 1;
195     }
196
197     for( i_dummy = 0; i_dummy < 64; i_dummy++ )
198     {
199         p_matrix->pi_matrix[p_vpar->ppi_scan[0][i_dummy]]
200              = GetBits( &p_vpar->bit_stream, 8 );
201     }
202 }
203
204 /*****************************************************************************
205  * LinkMatrix : Link a quantization matrix to another
206  *****************************************************************************/
207 static __inline__ void LinkMatrix( quant_matrix_t * p_matrix, u8 * pi_array )
208 {
209     if( p_matrix->b_allocated )
210     {
211         /* Deallocate the piece of memory. */
212         free( p_matrix->pi_matrix );
213         p_matrix->b_allocated = 0;
214     }
215
216     p_matrix->pi_matrix = pi_array;
217 }
218
219 /*
220  * Exported functions.
221  */
222
223 /*****************************************************************************
224  * vpar_NextSequenceHeader : Find the next sequence header
225  *****************************************************************************/
226 int vpar_NextSequenceHeader( vpar_thread_t * p_vpar )
227 {
228     while( !p_vpar->p_fifo->b_die )
229     {
230         NextStartCode( &p_vpar->bit_stream );
231         if( ShowBits( &p_vpar->bit_stream, 32 ) == SEQUENCE_HEADER_CODE )
232         {
233             return 0;
234         }
235         RemoveBits( &p_vpar->bit_stream, 8 );
236     }
237     return 1;
238 }
239
240 /*****************************************************************************
241  * vpar_ParseHeader : Parse the next header
242  *****************************************************************************/
243 int vpar_ParseHeader( vpar_thread_t * p_vpar )
244 {
245     while( !p_vpar->p_fifo->b_die )
246     {
247         NextStartCode( &p_vpar->bit_stream );
248         switch( GetBits32( &p_vpar->bit_stream ) )
249         {
250         case SEQUENCE_HEADER_CODE:
251 #ifdef STATS
252             p_vpar->c_sequences++;
253 #endif
254             SequenceHeader( p_vpar );
255             return 0;
256             break;
257
258         case GROUP_START_CODE:
259             GroupHeader( p_vpar );
260             return 0;
261             break;
262
263         case PICTURE_START_CODE:
264             PictureHeader( p_vpar );
265             return 0;
266             break;
267
268         case SEQUENCE_END_CODE:
269             intf_DbgMsg("vpar debug: sequence end code received");
270             return 1;
271             break;
272
273         default:
274             break;
275         }
276     }
277
278     return 0;
279 }
280
281 /*
282  * Following functions are local
283  */
284
285 /*****************************************************************************
286  * SequenceHeader : Parse the next sequence header
287  *****************************************************************************/
288 static void SequenceHeader( vpar_thread_t * p_vpar )
289 {
290 #define RESERVED    -1
291     static int i_frame_rate_table[16] =
292     {
293         0,
294         23 * 1000,
295         24 * 1001,
296         25 * 1001,
297         30 * 1000,
298         30 * 1001,
299         50 * 1001,
300         60 * 1000,
301         60 * 1001,
302         RESERVED, RESERVED, RESERVED, RESERVED, RESERVED, RESERVED, RESERVED
303     };
304 #undef RESERVED
305
306     int i_height_save, i_width_save;
307
308     i_height_save = p_vpar->sequence.i_height;
309     i_width_save = p_vpar->sequence.i_width;
310
311     p_vpar->sequence.i_width = GetBits( &p_vpar->bit_stream, 12 );
312     p_vpar->sequence.i_height = GetBits( &p_vpar->bit_stream, 12 );
313     p_vpar->sequence.i_aspect_ratio = GetBits( &p_vpar->bit_stream, 4 );
314     p_vpar->sequence.i_frame_rate =
315             i_frame_rate_table[ GetBits( &p_vpar->bit_stream, 4 ) ];
316
317     /* We don't need bit_rate_value, marker_bit, vbv_buffer_size,
318      * constrained_parameters_flag */
319     RemoveBits( &p_vpar->bit_stream, 30 );
320
321     /*
322      * Quantization matrices
323      */
324     if( GetBits( &p_vpar->bit_stream, 1 ) ) /* load_intra_quantizer_matrix */
325     {
326         LoadMatrix( p_vpar, &p_vpar->sequence.intra_quant );
327     }
328     else
329     {
330         /* Use default matrix. */
331         LinkMatrix( &p_vpar->sequence.intra_quant,
332                     p_vpar->pi_default_intra_quant );
333     }
334
335     if( GetBits(&p_vpar->bit_stream, 1) ) /* load_non_intra_quantizer_matrix */
336     {
337         LoadMatrix( p_vpar, &p_vpar->sequence.nonintra_quant );
338     }
339     else
340     {
341         /* Use default matrix. */
342         LinkMatrix( &p_vpar->sequence.nonintra_quant,
343                     p_vpar->pi_default_nonintra_quant );
344     }
345
346     /* Unless later overwritten by a matrix extension, we have the same
347      * matrices for luminance and chrominance. */
348     LinkMatrix( &p_vpar->sequence.chroma_intra_quant,
349                 p_vpar->sequence.intra_quant.pi_matrix );
350     LinkMatrix( &p_vpar->sequence.chroma_nonintra_quant,
351                 p_vpar->sequence.nonintra_quant.pi_matrix );
352
353     /*
354      * Sequence Extension
355      */
356     NextStartCode( &p_vpar->bit_stream );
357     if( ShowBits( &p_vpar->bit_stream, 32 ) == EXTENSION_START_CODE )
358     {
359         int                         i_dummy;
360
361         /* Turn the MPEG2 flag on */
362         p_vpar->sequence.b_mpeg2 = 1;
363
364         /* Parse sequence_extension */
365         RemoveBits32( &p_vpar->bit_stream );
366         /* extension_start_code_identifier, profile_and_level_indication */
367         RemoveBits( &p_vpar->bit_stream, 12 );
368         p_vpar->sequence.b_progressive = GetBits( &p_vpar->bit_stream, 1 );
369         p_vpar->sequence.i_chroma_format = GetBits( &p_vpar->bit_stream, 2 );
370         p_vpar->sequence.i_width |= GetBits( &p_vpar->bit_stream, 2 ) << 12;
371         p_vpar->sequence.i_height |= GetBits( &p_vpar->bit_stream, 2 ) << 12;
372         /* bit_rate_extension, marker_bit, vbv_buffer_size_extension,
373          * low_delay */
374         RemoveBits( &p_vpar->bit_stream, 22 );
375         /* frame_rate_extension_n */
376         i_dummy = GetBits( &p_vpar->bit_stream, 2 );
377         /* frame_rate_extension_d */
378         p_vpar->sequence.i_frame_rate *= (i_dummy + 1)
379                                   / (GetBits( &p_vpar->bit_stream, 5 ) + 1);
380     }
381     else
382     {
383         /* It's an MPEG-1 stream. Put adequate parameters. */
384
385         p_vpar->sequence.b_mpeg2 = 0;
386         p_vpar->sequence.b_progressive = 1;
387         p_vpar->sequence.i_chroma_format = CHROMA_420;
388     }
389
390     /* Update sizes */
391     p_vpar->sequence.i_mb_width = (p_vpar->sequence.i_width + 15) / 16;
392     p_vpar->sequence.i_mb_height = (p_vpar->sequence.b_progressive) ?
393                                    (p_vpar->sequence.i_height + 15) / 16 :
394                                    2 * ((p_vpar->sequence.i_height + 31) / 32);
395     p_vpar->sequence.i_mb_size = p_vpar->sequence.i_mb_width
396                                         * p_vpar->sequence.i_mb_height;
397     p_vpar->sequence.i_width = (p_vpar->sequence.i_mb_width * 16);
398     p_vpar->sequence.i_height = (p_vpar->sequence.i_mb_height * 16);
399     p_vpar->sequence.i_size = p_vpar->sequence.i_width
400                                         * p_vpar->sequence.i_height;
401
402 #if 0
403     if(    p_vpar->sequence.i_width != i_width_save
404         || p_vpar->sequence.i_height != i_height_save )
405     {
406          /* FIXME: Warn the video output */
407     }
408 #endif
409
410     /* Extension and User data */
411     ExtensionAndUserData( p_vpar );
412
413     /* XXX: The vout request and fifo opening will eventually be here */
414
415     /* Spawn a video output if there is none */
416     vlc_mutex_lock( &p_vout_bank->lock );
417     
418     if( p_vout_bank->i_count == 0 )
419     {
420         intf_WarnMsg( 1, "vpar: no vout present, spawning one" );
421
422         p_vpar->p_vout = vout_CreateThread( NULL );
423
424         /* Everything failed */
425         if( p_vpar->p_vout == NULL )
426         {
427             intf_ErrMsg( "vpar error: can't open vout, aborting" );
428             vlc_mutex_unlock( &p_vout_bank->lock );
429
430             /* XXX ! XXX ! XXX ! what to do here ? */
431             return;
432         }
433         
434         p_vout_bank->pp_vout[ p_vout_bank->i_count ] = p_vpar->p_vout;
435         p_vout_bank->i_count++;
436     }
437     else
438     {
439         /* Take the first video output FIXME: take the best one */
440         p_vpar->p_vout = p_vout_bank->pp_vout[ 0 ];
441     }
442
443     vlc_mutex_unlock( &p_vout_bank->lock );
444 }
445
446 /*****************************************************************************
447  * GroupHeader : Parse the next group of pictures header
448  *****************************************************************************/
449 static void GroupHeader( vpar_thread_t * p_vpar )
450 {
451     /* Nothing to do, we don't care. */
452     RemoveBits( &p_vpar->bit_stream, 27 );
453     ExtensionAndUserData( p_vpar );
454 }
455
456 /*****************************************************************************
457  * PictureHeader : Parse the next picture header
458  *****************************************************************************/
459 static void PictureHeader( vpar_thread_t * p_vpar )
460 {
461     int                 i_structure;
462     boolean_t           b_parsable;
463 #ifdef VDEC_SMP
464     int                 i_mb;
465 #endif
466
467     /* Recover in case of stream discontinuity. */
468     if( p_vpar->sequence.b_expect_discontinuity )
469     {
470         ReferenceUpdate( p_vpar, I_CODING_TYPE, NULL );
471         ReferenceUpdate( p_vpar, I_CODING_TYPE, NULL );
472         if( p_vpar->picture.p_picture != NULL )
473         {
474             vout_DestroyPicture( p_vpar->p_vout, p_vpar->picture.p_picture );
475             p_vpar->picture.p_picture = NULL;
476         }
477         p_vpar->picture.i_current_structure = 0;
478         p_vpar->sequence.b_expect_discontinuity = 0;
479     }
480
481     /* Parse the picture header. */
482     RemoveBits( &p_vpar->bit_stream, 10 ); /* temporal_reference */
483     p_vpar->picture.i_coding_type = GetBits( &p_vpar->bit_stream, 3 );
484     RemoveBits( &p_vpar->bit_stream, 16 ); /* vbv_delay */
485
486     if( p_vpar->picture.i_coding_type == P_CODING_TYPE
487         || p_vpar->picture.i_coding_type == B_CODING_TYPE )
488     {
489         p_vpar->picture.ppi_f_code[0][1] = GetBits( &p_vpar->bit_stream, 1 );
490         p_vpar->picture.ppi_f_code[0][0] = GetBits( &p_vpar->bit_stream, 3 )
491                                             - 1;
492     }
493     if( p_vpar->picture.i_coding_type == B_CODING_TYPE )
494     {
495         p_vpar->picture.ppi_f_code[1][1] = GetBits( &p_vpar->bit_stream, 1 );
496         p_vpar->picture.ppi_f_code[1][0] = GetBits( &p_vpar->bit_stream, 3 )
497                                             - 1;
498     }
499
500     /* extra_information_picture */
501     while( GetBits( &p_vpar->bit_stream, 1 ) )
502     {
503         RemoveBits( &p_vpar->bit_stream, 8 );
504     }
505
506     /*
507      * Picture Coding Extension
508      */
509     NextStartCode( &p_vpar->bit_stream );
510     if( ShowBits( &p_vpar->bit_stream, 32 ) == EXTENSION_START_CODE )
511     {
512         /* Parse picture_coding_extension */
513         RemoveBits32( &p_vpar->bit_stream );
514         /* extension_start_code_identifier */
515         RemoveBits( &p_vpar->bit_stream, 4 );
516
517         /* Pre-substract 1 for later use in MotionDelta(). */
518         p_vpar->picture.ppi_f_code[0][0] = GetBits( &p_vpar->bit_stream, 4 ) -1;
519         p_vpar->picture.ppi_f_code[0][1] = GetBits( &p_vpar->bit_stream, 4 ) -1;
520         p_vpar->picture.ppi_f_code[1][0] = GetBits( &p_vpar->bit_stream, 4 ) -1;
521         p_vpar->picture.ppi_f_code[1][1] = GetBits( &p_vpar->bit_stream, 4 ) -1;
522         p_vpar->picture.i_intra_dc_precision = GetBits( &p_vpar->bit_stream, 2 );
523         i_structure = GetBits( &p_vpar->bit_stream, 2 );
524         p_vpar->picture.b_top_field_first = GetBits( &p_vpar->bit_stream, 1 );
525         p_vpar->picture.b_frame_pred_frame_dct
526              = GetBits( &p_vpar->bit_stream, 1 );
527         p_vpar->picture.b_concealment_mv = GetBits( &p_vpar->bit_stream, 1 );
528         p_vpar->picture.b_q_scale_type = GetBits( &p_vpar->bit_stream, 1 );
529         p_vpar->picture.b_intra_vlc_format = GetBits( &p_vpar->bit_stream, 1 );
530         /* Alternate scan */
531         p_vpar->picture.pi_scan =
532             p_vpar->ppi_scan[ GetBits( &p_vpar->bit_stream, 1 ) ];
533         p_vpar->picture.b_repeat_first_field = GetBits( &p_vpar->bit_stream, 1 );
534         /* chroma_420_type (obsolete) */
535         RemoveBits( &p_vpar->bit_stream, 1 );
536         p_vpar->picture.b_progressive = GetBits( &p_vpar->bit_stream, 1 );
537
538         /* composite_display_flag */
539         if( GetBits( &p_vpar->bit_stream, 1 ) )
540         {
541             /* v_axis, field_sequence, sub_carrier, burst_amplitude,
542              * sub_carrier_phase */
543             RemoveBits( &p_vpar->bit_stream, 20 );
544         }
545     }
546     else
547     {
548         /* MPEG-1 compatibility flags */
549         p_vpar->picture.i_intra_dc_precision = 0; /* 8 bits */
550         i_structure = FRAME_STRUCTURE;
551         p_vpar->picture.b_top_field_first = 0;
552         p_vpar->picture.b_frame_pred_frame_dct = 1;
553         p_vpar->picture.b_concealment_mv = 0;
554         p_vpar->picture.b_q_scale_type = 0;
555         p_vpar->picture.b_intra_vlc_format = 0;
556         p_vpar->picture.pi_scan = p_vpar->ppi_scan[0];
557         p_vpar->picture.b_repeat_first_field = 0;
558         p_vpar->picture.b_progressive = 1;
559     }
560
561     /* Extension and User data. */
562     ExtensionAndUserData( p_vpar );
563
564 #ifdef STATS
565     p_vpar->pc_pictures[p_vpar->picture.i_coding_type]++;
566 #endif
567
568     if( p_vpar->picture.i_current_structure &&
569         (i_structure == FRAME_STRUCTURE ||
570          i_structure == p_vpar->picture.i_current_structure) )
571     {
572         /* We don't have the second field of the buffered frame. */
573         if( p_vpar->picture.p_picture != NULL )
574         {
575             ReferenceReplace( p_vpar,
576                       p_vpar->picture.i_coding_type,
577                       NULL );
578             vout_DestroyPicture( p_vpar->p_vout, p_vpar->picture.p_picture );
579             p_vpar->picture.p_picture = NULL;
580         }
581
582         p_vpar->picture.i_current_structure = 0;
583
584         intf_WarnMsg( 2, "Odd number of field pictures." );
585     }
586
587     /* Do we have the reference pictures ? */
588     b_parsable = !(((p_vpar->picture.i_coding_type == P_CODING_TYPE ||
589                      p_vpar->picture.b_concealment_mv) &&
590                     (p_vpar->sequence.p_backward == NULL)) ||
591                      /* p_backward will become p_forward later */
592                    ((p_vpar->picture.i_coding_type == B_CODING_TYPE) &&
593                     (p_vpar->sequence.p_forward == NULL ||
594                      p_vpar->sequence.p_backward == NULL)));
595
596     if( p_vpar->picture.i_current_structure )
597     {
598         /* Second field of a frame. We will decode it if, and only if we
599          * have decoded the first field. */
600         if( b_parsable )
601         {
602             if( p_vpar->picture.p_picture == NULL )
603             {
604                 if( (p_vpar->picture.i_coding_type == I_CODING_TYPE
605                       && p_vpar->sequence.p_backward == NULL) )
606                 {
607                     /* Exceptionnally, parse the picture if it is I. We need
608                      * this in case of an odd number of field pictures, if the
609                      * previous picture is not intra, we desperately need a
610                      * new reference picture. OK, this is kind of kludgy. */
611                     p_vpar->picture.i_current_structure = 0;
612                 }
613                 else
614                 {
615                     b_parsable = 0;
616                 }
617             }
618         }
619     }
620     else
621     {
622         int     i_repeat_field;
623
624         /* Compute the number of times the frame will be emitted by the
625          * decoder (number of half-periods). */
626         if( p_vpar->sequence.b_progressive )
627         {
628             i_repeat_field = (1 + p_vpar->picture.b_repeat_first_field
629                                 + p_vpar->picture.b_top_field_first) * 2;
630         }
631         else
632         {
633             if( p_vpar->picture.b_progressive )
634             {
635                 i_repeat_field = 2 + p_vpar->picture.b_repeat_first_field;
636             }
637             else
638             {
639                 i_repeat_field = 2;
640             }
641         }
642
643         /* Warn synchro we have a new picture (updates pictures index). */
644         vpar_SynchroNewPicture( p_vpar, p_vpar->picture.i_coding_type,
645                                 i_repeat_field );
646
647         if( b_parsable )
648         {
649             /* Does synchro say we have enough time to decode it ? */
650             b_parsable = vpar_SynchroChoose( p_vpar,
651                                p_vpar->picture.i_coding_type, i_structure );
652         }
653     }
654
655     if( !b_parsable )
656     {
657         /* Update the reference pointers. */
658         ReferenceUpdate( p_vpar, p_vpar->picture.i_coding_type, NULL );
659
660         /* Update context. */
661         if( i_structure != FRAME_STRUCTURE )
662         {
663             if( (p_vpar->picture.i_current_structure | i_structure)
664                     == FRAME_STRUCTURE )
665             {
666                 /* The frame is complete. */
667                 p_vpar->picture.i_current_structure = 0;
668
669                 vpar_SynchroTrash( p_vpar, p_vpar->picture.i_coding_type, i_structure );
670             }
671             else
672             {
673                 p_vpar->picture.i_current_structure = i_structure;
674             }
675         }
676         else
677         {
678             /* Warn Synchro we have trashed a picture. */
679             vpar_SynchroTrash( p_vpar, p_vpar->picture.i_coding_type, i_structure );
680         }
681         p_vpar->picture.p_picture = NULL;
682
683         return;
684     }
685
686     /* OK, now we are sure we will decode the picture. */
687 #ifdef STATS
688     p_vpar->pc_decoded_pictures[p_vpar->picture.i_coding_type]++;
689 #endif
690
691 #define P_picture p_vpar->picture.p_picture
692     p_vpar->picture.b_error = 0;
693     p_vpar->picture.b_frame_structure = (i_structure == FRAME_STRUCTURE);
694
695     if( !p_vpar->picture.i_current_structure )
696     {
697         /* This is a new frame. Get a structure from the video_output. */
698         while( ( P_picture = vout_CreatePicture( p_vpar->p_vout,
699                               /* XXX */ 99+p_vpar->sequence.i_chroma_format,
700                                         p_vpar->sequence.i_width,
701                                         p_vpar->sequence.i_height ) )
702              == NULL )
703         {
704             intf_DbgMsg("vpar debug: allocation error in vout_CreatePicture, delaying");
705             if( p_vpar->p_fifo->b_die || p_vpar->p_fifo->b_error )
706             {
707                 return;
708             }
709             msleep( VPAR_OUTMEM_SLEEP );
710         }
711
712         /* Initialize values. */
713         vpar_SynchroDecode( p_vpar, p_vpar->picture.i_coding_type, i_structure );
714         P_picture->i_aspect_ratio = p_vpar->sequence.i_aspect_ratio;
715         P_picture->i_matrix_coefficients = p_vpar->sequence.i_matrix_coefficients;
716         p_vpar->picture.i_field_width = ( p_vpar->sequence.i_width
717                     << ( 1 - p_vpar->picture.b_frame_structure ) );
718
719 /* FIXME ! remove asap ?? */
720 //memset( P_picture->p_data, 0, (p_vpar->sequence.i_mb_size*384));
721
722         /* Update the reference pointers. */
723         ReferenceUpdate( p_vpar, p_vpar->picture.i_coding_type, P_picture );
724     }
725
726     /* Initialize picture data for decoding. */
727     p_vpar->picture.i_current_structure |= i_structure;
728     p_vpar->picture.i_structure = i_structure;
729     p_vpar->picture.b_second_field =
730         (i_structure != p_vpar->picture.i_current_structure);
731     p_vpar->picture.b_current_field =
732         (i_structure == BOTTOM_FIELD );
733
734     if( p_vpar->sequence.b_mpeg2 )
735     {
736         static f_picture_data_t ppf_picture_data[4][4] =
737         {
738             {
739                 NULL, NULL, NULL, NULL
740             },
741             {
742                 /* TOP_FIELD */
743 #if (VPAR_OPTIM_LEVEL > 1)
744                 NULL, vpar_PictureData2IT, vpar_PictureData2PT,
745                 vpar_PictureData2BT
746 #else
747                 NULL, vpar_PictureDataGENERIC, vpar_PictureDataGENERIC,
748                 vpar_PictureDataGENERIC
749 #endif
750             },
751             {
752                 /* BOTTOM_FIELD */
753 #if (VPAR_OPTIM_LEVEL > 1)
754                 NULL, vpar_PictureData2IB, vpar_PictureData2PB,
755                 vpar_PictureData2BB
756 #else
757                 NULL, vpar_PictureDataGENERIC, vpar_PictureDataGENERIC,
758                 vpar_PictureDataGENERIC
759 #endif
760             },
761             {
762                 /* FRAME_PICTURE */
763 #if (VPAR_OPTIM_LEVEL > 0)
764                 NULL, vpar_PictureData2IF, vpar_PictureData2PF,
765                 vpar_PictureData2BF
766 #else
767                 NULL, vpar_PictureDataGENERIC, vpar_PictureDataGENERIC,
768                 vpar_PictureDataGENERIC
769 #endif
770             }
771         };
772
773         ppf_picture_data[p_vpar->picture.i_structure]
774                         [p_vpar->picture.i_coding_type]( p_vpar );
775     }
776     else
777     {
778 #if (VPAR_OPTIM_LEVEL > 0)
779         static f_picture_data_t pf_picture_data[5] =
780         { NULL, vpar_PictureData1I, vpar_PictureData1P, vpar_PictureData1B,
781           vpar_PictureData1D };
782
783         pf_picture_data[p_vpar->picture.i_coding_type]( p_vpar );
784 #else
785         vpar_PictureDataGENERIC( p_vpar );
786 #endif
787     }
788
789     /* Wait for all the macroblocks to be decoded. */
790     p_vpar->pool.pf_wait_pool( &p_vpar->pool );
791
792     /* Re-spawn decoder threads if the user changed settings. */
793     vpar_SpawnPool( p_vpar );
794
795     if( p_vpar->p_fifo->b_die || p_vpar->p_fifo->b_error )
796     {
797         return;
798     }
799
800     if( p_vpar->picture.b_error )
801     {
802         /* Trash picture. */
803 #ifdef STATS
804         p_vpar->pc_malformed_pictures[p_vpar->picture.i_coding_type]++;
805 #endif
806
807         vpar_SynchroEnd( p_vpar, p_vpar->picture.i_coding_type,
808                          p_vpar->picture.i_structure, 1 );
809         vout_DestroyPicture( p_vpar->p_vout, P_picture );
810
811         ReferenceReplace( p_vpar, p_vpar->picture.i_coding_type, NULL );
812
813         /* Prepare context for the next picture. */
814         P_picture = NULL;
815         if( p_vpar->picture.i_current_structure == FRAME_STRUCTURE )
816             p_vpar->picture.i_current_structure = 0;
817     }
818     else if( p_vpar->picture.i_current_structure == FRAME_STRUCTURE )
819     {
820         /* Frame completely parsed. */
821         vpar_SynchroEnd( p_vpar, p_vpar->picture.i_coding_type,
822                          p_vpar->picture.i_structure, 0 );
823         vout_DisplayPicture( p_vpar->p_vout, P_picture );
824
825         /* Prepare context for the next picture. */
826         P_picture = NULL;
827         p_vpar->picture.i_current_structure = 0;
828     }
829 #undef P_picture
830 }
831
832 /*****************************************************************************
833  * ExtensionAndUserData : Parse the extension_and_user_data structure
834  *****************************************************************************/
835 static void ExtensionAndUserData( vpar_thread_t * p_vpar )
836 {
837     while( !p_vpar->p_fifo->b_die )
838     {
839         NextStartCode( &p_vpar->bit_stream );
840         switch( ShowBits( &p_vpar->bit_stream, 32 ) )
841         {
842         case EXTENSION_START_CODE:
843             RemoveBits32( &p_vpar->bit_stream );
844             switch( GetBits( &p_vpar->bit_stream, 4 ) )
845             {
846             case SEQUENCE_DISPLAY_EXTENSION_ID:
847                 SequenceDisplayExtension( p_vpar );
848                 break;
849             case QUANT_MATRIX_EXTENSION_ID:
850                 QuantMatrixExtension( p_vpar );
851                 break;
852             case SEQUENCE_SCALABLE_EXTENSION_ID:
853                 SequenceScalableExtension( p_vpar );
854                 break;
855             case PICTURE_DISPLAY_EXTENSION_ID:
856                 PictureDisplayExtension( p_vpar );
857                 break;
858             case PICTURE_SPATIAL_SCALABLE_EXTENSION_ID:
859                 PictureSpatialScalableExtension( p_vpar );
860                 break;
861             case PICTURE_TEMPORAL_SCALABLE_EXTENSION_ID:
862                 PictureTemporalScalableExtension( p_vpar );
863                 break;
864             case COPYRIGHT_EXTENSION_ID:
865                 CopyrightExtension( p_vpar );
866                 break;
867             default:
868                 break;
869             }
870             break;
871
872         case USER_DATA_START_CODE:
873             RemoveBits32( &p_vpar->bit_stream );
874             /* Wait for the next start code */
875             break;
876
877         default:
878             return;
879         }
880     }
881 }
882
883
884 /*****************************************************************************
885  * SequenceDisplayExtension : Parse the sequence_display_extension structure *
886  *****************************************************************************/
887
888 static void SequenceDisplayExtension( vpar_thread_t * p_vpar )
889 {
890     /* We don't care sequence_display_extension. */
891     /* video_format */
892     RemoveBits( &p_vpar->bit_stream, 3 );
893     if( GetBits( &p_vpar->bit_stream, 1 ) )
894     {
895         /* Two bytes for color_desciption */
896         RemoveBits( &p_vpar->bit_stream, 16 );
897         p_vpar->sequence.i_matrix_coefficients = GetBits( &p_vpar->bit_stream, 8 );
898     }
899     /* display_horizontal and vertical_size and a marker_bit */
900     RemoveBits( &p_vpar->bit_stream, 29 );
901 }
902
903
904 /*****************************************************************************
905  * QuantMatrixExtension : Load quantization matrices for luminance           *
906  *                        and chrominance                                    *
907  *****************************************************************************/
908
909 static void QuantMatrixExtension( vpar_thread_t * p_vpar )
910 {
911     if( GetBits( &p_vpar->bit_stream, 1 ) )
912     {
913         /* Load intra_quantiser_matrix for luminance. */
914         LoadMatrix( p_vpar, &p_vpar->sequence.intra_quant );
915     }
916     else
917     {
918         /* Use the default matrix. */
919         LinkMatrix( &p_vpar->sequence.intra_quant,
920                     p_vpar->pi_default_intra_quant );
921     }
922     if( GetBits( &p_vpar->bit_stream, 1 ) )
923     {
924         /* Load non_intra_quantiser_matrix for luminance. */
925         LoadMatrix( p_vpar, &p_vpar->sequence.nonintra_quant );
926     }
927     else
928     {
929         /* Use the default matrix. */
930         LinkMatrix( &p_vpar->sequence.nonintra_quant,
931                     p_vpar->pi_default_nonintra_quant );
932     }
933     if( GetBits( &p_vpar->bit_stream, 1 ) )
934     {
935         /* Load intra_quantiser_matrix for chrominance. */
936         LoadMatrix( p_vpar, &p_vpar->sequence.chroma_intra_quant );
937     }
938     else
939     {
940         /* Link the chrominance intra matrix to the luminance one. */
941         LinkMatrix( &p_vpar->sequence.chroma_intra_quant,
942                     p_vpar->sequence.intra_quant.pi_matrix );
943     }
944     if( GetBits( &p_vpar->bit_stream, 1 ) )
945     {
946         /* Load non_intra_quantiser_matrix for chrominance. */
947         LoadMatrix( p_vpar, &p_vpar->sequence.chroma_nonintra_quant );
948     }
949     else
950     {
951         /* Link the chrominance intra matrix to the luminance one. */
952         LinkMatrix( &p_vpar->sequence.chroma_intra_quant,
953                     p_vpar->sequence.intra_quant.pi_matrix );
954     }
955     if( GetBits( &p_vpar->bit_stream, 1 ) )
956     {
957         /* Load non_intra_quantiser_matrix for chrominance. */
958         LoadMatrix( p_vpar, &p_vpar->sequence.chroma_nonintra_quant );
959     }
960     else
961     {
962         /* Link the chrominance nonintra matrix to the luminance one. */
963         LinkMatrix( &p_vpar->sequence.chroma_nonintra_quant,
964                     p_vpar->sequence.nonintra_quant.pi_matrix );
965     }
966 }
967
968
969 /*****************************************************************************
970  * SequenceScalableExtension : Parse the sequence_scalable_extension         *
971  *                             structure to handle scalable coding           *
972  *****************************************************************************/
973
974 static void SequenceScalableExtension( vpar_thread_t * p_vpar )
975 {
976     /* We don't care about anything scalable except the scalable mode. */
977     switch( p_vpar->sequence.i_scalable_mode = GetBits( &p_vpar->bit_stream, 2 ) )
978     /* The length of the structure depends on the value of the scalable_mode */
979     {
980         case 1:
981             RemoveBits32( &p_vpar->bit_stream );
982             RemoveBits( &p_vpar->bit_stream, 21 );
983             break;
984         case 2:
985             RemoveBits( &p_vpar->bit_stream, 12 );
986             break;
987         default:
988             RemoveBits( &p_vpar->bit_stream, 4 );
989     }
990
991 }
992 /*****************************************************************************
993  * PictureDisplayExtension : Parse the picture_display_extension structure   *
994  *****************************************************************************/
995
996 static void PictureDisplayExtension( vpar_thread_t * p_vpar )
997 {
998     /* Number of frame center offset */
999     int i_nb, i_dummy;
1000     /* I am not sure it works but it should
1001         (fewer tests than shown in §6.3.12) */
1002     i_nb = p_vpar->sequence.b_progressive ? p_vpar->sequence.b_progressive +
1003                                             p_vpar->picture.b_repeat_first_field +
1004                                             p_vpar->picture.b_top_field_first
1005                            : ( p_vpar->picture.b_frame_structure + 1 ) +
1006                              p_vpar->picture.b_repeat_first_field;
1007     for( i_dummy = 0; i_dummy < i_nb; i_dummy++ )
1008     {
1009         RemoveBits( &p_vpar->bit_stream, 17 );
1010         RemoveBits( &p_vpar->bit_stream, 17 );
1011     }
1012 }
1013
1014
1015 /*****************************************************************************
1016  * PictureSpatialScalableExtension                                           *
1017  *****************************************************************************/
1018
1019 static void PictureSpatialScalableExtension( vpar_thread_t * p_vpar )
1020 {
1021     /* That's scalable, so we trash it */
1022     RemoveBits32( &p_vpar->bit_stream );
1023     RemoveBits( &p_vpar->bit_stream, 16 );
1024 }
1025
1026
1027 /*****************************************************************************
1028  * PictureTemporalScalableExtension                                          *
1029  *****************************************************************************/
1030
1031 static void PictureTemporalScalableExtension( vpar_thread_t * p_vpar )
1032 {
1033     /* Scalable again, trashed again */
1034     RemoveBits( &p_vpar->bit_stream, 23 );
1035 }
1036
1037
1038 /*****************************************************************************
1039  * CopyrightExtension : Keeps some legal informations                        *
1040  *****************************************************************************/
1041
1042 static void CopyrightExtension( vpar_thread_t * p_vpar )
1043 {
1044     u32     i_copyright_nb_1, i_copyright_nb_2; /* local integers */
1045     p_vpar->sequence.b_copyright_flag = GetBits( &p_vpar->bit_stream, 1 );
1046         /* A flag that says whether the copyright information is significant */
1047     p_vpar->sequence.i_copyright_id = GetBits( &p_vpar->bit_stream, 8 );
1048         /* An identifier compliant with ISO/CEI JTC 1/SC 29 */
1049     p_vpar->sequence.b_original = GetBits( &p_vpar->bit_stream, 1 );
1050         /* Reserved bits */
1051     RemoveBits( &p_vpar->bit_stream, 8 );
1052         /* The copyright_number is split in three parts */
1053         /* first part */
1054     i_copyright_nb_1 = GetBits( &p_vpar->bit_stream, 20 );
1055     RemoveBits( &p_vpar->bit_stream, 1 );
1056         /* second part */
1057     i_copyright_nb_2 = GetBits( &p_vpar->bit_stream, 22 );
1058     RemoveBits( &p_vpar->bit_stream, 1 );
1059         /* third part and sum */
1060     p_vpar->sequence.i_copyright_nb = ( (u64)i_copyright_nb_1 << 44 ) |
1061                                       ( (u64)i_copyright_nb_2 << 22 ) |
1062                                       ( (u64)GetBits( &p_vpar->bit_stream, 22 ) );
1063 }