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[vlc] / modules / codec / libmpeg2.c
1 /*****************************************************************************
2  * libmpeg2.c: mpeg2 video decoder module making use of libmpeg2.
3  *****************************************************************************
4  * Copyright (C) 1999-2001 the VideoLAN team
5  * $Id$
6  *
7  * Authors: Gildas Bazin <gbazin@videolan.org>
8  *          Christophe Massiot <massiot@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., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
23  *****************************************************************************/
24
25 /*****************************************************************************
26  * Preamble
27  *****************************************************************************/
28 #ifdef HAVE_CONFIG_H
29 # include "config.h"
30 #endif
31 #include <assert.h>
32
33 #include <vlc_common.h>
34 #include <vlc_plugin.h>
35 #include <vlc_codec.h>
36 #include <vlc_block_helper.h>
37 #include <vlc_cpu.h>
38 #include "../codec/cc.h"
39
40 #include <mpeg2.h>
41
42 #include <vlc_codec_synchro.h>
43
44 /*****************************************************************************
45  * decoder_sys_t : libmpeg2 decoder descriptor
46  *****************************************************************************/
47 #define DPB_COUNT (3+1)
48 typedef struct
49 {
50     picture_t *p_picture;
51     bool      b_linked;
52     bool      b_displayed;
53 } picture_dpb_t;
54
55 struct decoder_sys_t
56 {
57     /*
58      * libmpeg2 properties
59      */
60     mpeg2dec_t          *p_mpeg2dec;
61     const mpeg2_info_t  *p_info;
62     bool                b_skip;
63
64     /*
65      * Input properties
66      */
67     mtime_t          i_previous_pts;
68     mtime_t          i_current_pts;
69     mtime_t          i_previous_dts;
70     mtime_t          i_current_dts;
71     bool             b_garbage_pic;
72     bool             b_after_sequence_header; /* is it the next frame after
73                                                * the sequence header ?    */
74     bool             b_slice_i;             /* intra-slice refresh stream */
75     bool             b_second_field;
76
77     bool             b_preroll;
78
79     /* */
80     picture_dpb_t        p_dpb[DPB_COUNT];
81
82     /*
83      * Output properties
84      */
85     decoder_synchro_t *p_synchro;
86     int             i_sar_num;
87     int             i_sar_den;
88     mtime_t         i_last_frame_pts;
89
90     /* Closed captioning support */
91     uint32_t        i_cc_flags;
92     mtime_t         i_cc_pts;
93     mtime_t         i_cc_dts;
94     cc_data_t       cc;
95     uint8_t        *p_gop_user_data;
96     uint32_t        i_gop_user_data;
97 };
98
99 /*****************************************************************************
100  * Local prototypes
101  *****************************************************************************/
102 static int  OpenDecoder( vlc_object_t * );
103 static void CloseDecoder( vlc_object_t * );
104
105 static picture_t *DecodeBlock( decoder_t *, block_t ** );
106 #if MPEG2_RELEASE >= MPEG2_VERSION (0, 5, 0)
107 static block_t   *GetCc( decoder_t *p_dec, bool pb_present[4] );
108 #endif
109
110 static picture_t *GetNewPicture( decoder_t * );
111 static void PutPicture( decoder_t *, picture_t * );
112
113 static void GetAR( decoder_t *p_dec );
114
115 static void Reset( decoder_t *p_dec );
116
117 /* */
118 static void DpbInit( decoder_t * );
119 static void DpbClean( decoder_t * );
120 static picture_t *DpbNewPicture( decoder_t * );
121 static void DpbUnlinkPicture( decoder_t *, picture_t * );
122 static int DpbDisplayPicture( decoder_t *, picture_t * );
123
124 /*****************************************************************************
125  * Module descriptor
126  *****************************************************************************/
127 vlc_module_begin ()
128     set_description( N_("MPEG I/II video decoder (using libmpeg2)") )
129     set_capability( "decoder", 50 )
130     set_category( CAT_INPUT )
131     set_subcategory( SUBCAT_INPUT_VCODEC )
132     set_callbacks( OpenDecoder, CloseDecoder )
133     add_shortcut( "libmpeg2" )
134 vlc_module_end ()
135
136 /*****************************************************************************
137  * OpenDecoder: probe the decoder and return score
138  *****************************************************************************/
139 static int OpenDecoder( vlc_object_t *p_this )
140 {
141     decoder_t *p_dec = (decoder_t*)p_this;
142     decoder_sys_t *p_sys;
143     uint32_t i_accel = 0;
144
145     if( p_dec->fmt_in.i_codec != VLC_CODEC_MPGV )
146         return VLC_EGENERIC;
147
148     /* Select onl recognized original format (standard mpeg video) */
149     switch( p_dec->fmt_in.i_original_fourcc )
150     {
151     case VLC_FOURCC('m','p','g','1'):
152     case VLC_FOURCC('m','p','g','2'):
153     case VLC_FOURCC('m','p','g','v'):
154     case VLC_FOURCC('P','I','M','1'):
155     case VLC_FOURCC('h','d','v','2'):
156         break;
157     default:
158         if( p_dec->fmt_in.i_original_fourcc )
159             return VLC_EGENERIC;
160         break;
161     }
162
163     /* Allocate the memory needed to store the decoder's structure */
164     if( ( p_dec->p_sys = p_sys = calloc( 1, sizeof(*p_sys)) ) == NULL )
165         return VLC_ENOMEM;
166
167     /* Initialize the thread properties */
168     p_sys->p_mpeg2dec = NULL;
169     p_sys->p_synchro  = NULL;
170     p_sys->p_info     = NULL;
171     p_sys->i_current_pts  = 0;
172     p_sys->i_previous_pts = 0;
173     p_sys->i_current_dts  = 0;
174     p_sys->i_previous_dts = 0;
175     p_sys->i_sar_num = 0;
176     p_sys->i_sar_den = 0;
177     p_sys->b_garbage_pic = false;
178     p_sys->b_slice_i  = false;
179     p_sys->b_second_field = false;
180     p_sys->b_skip     = false;
181     p_sys->b_preroll = false;
182     DpbInit( p_dec );
183
184     p_sys->i_cc_pts = 0;
185     p_sys->i_cc_dts = 0;
186     p_sys->i_cc_flags = 0;
187 #if MPEG2_RELEASE >= MPEG2_VERSION (0, 5, 0)
188     p_dec->pf_get_cc = GetCc;
189     cc_Init( &p_sys->cc );
190 #endif
191     p_sys->p_gop_user_data = NULL;
192     p_sys->i_gop_user_data = 0;
193
194 #if defined( __i386__ ) || defined( __x86_64__ )
195     if( vlc_CPU() & CPU_CAPABILITY_MMX )
196     {
197         i_accel |= MPEG2_ACCEL_X86_MMX;
198     }
199
200     if( vlc_CPU() & CPU_CAPABILITY_3DNOW )
201     {
202         i_accel |= MPEG2_ACCEL_X86_3DNOW;
203     }
204
205     if( vlc_CPU() & CPU_CAPABILITY_MMXEXT )
206     {
207         i_accel |= MPEG2_ACCEL_X86_MMXEXT;
208     }
209
210 #elif defined( __powerpc__ ) || defined( __ppc__ ) || defined( __ppc64__ )
211     if( vlc_CPU() & CPU_CAPABILITY_ALTIVEC )
212     {
213         i_accel |= MPEG2_ACCEL_PPC_ALTIVEC;
214     }
215
216 #elif defined(__arm__) && defined(MPEG2_ACCEL_ARM)
217     i_accel |= MPEG2_ACCEL_ARM;
218
219 # ifdef MPEG2_ACCEL_ARM_NEON
220     if( vlc_CPU() & CPU_CAPABILITY_NEON )
221         i_accel |= MPEG2_ACCEL_ARM_NEON;
222 # endif
223
224 #else
225     /* If we do not know this CPU, trust libmpeg2's feature detection */
226     i_accel = MPEG2_ACCEL_DETECT;
227
228 #endif
229
230     /* Set CPU acceleration features */
231     mpeg2_accel( i_accel );
232
233     /* Initialize decoder */
234     p_sys->p_mpeg2dec = mpeg2_init();
235     if( p_sys->p_mpeg2dec == NULL)
236     {
237         msg_Err( p_dec, "mpeg2_init() failed" );
238         free( p_sys );
239         return VLC_EGENERIC;
240     }
241
242     p_sys->p_info = mpeg2_info( p_sys->p_mpeg2dec );
243
244     p_dec->pf_decode_video = DecodeBlock;
245     p_dec->fmt_out.i_cat = VIDEO_ES;
246     p_dec->fmt_out.i_codec = 0;
247
248     return VLC_SUCCESS;
249 }
250
251 /*****************************************************************************
252  * RunDecoder: the libmpeg2 decoder
253  *****************************************************************************/
254 static picture_t *DecodeBlock( decoder_t *p_dec, block_t **pp_block )
255 {
256     decoder_sys_t   *p_sys = p_dec->p_sys;
257     mpeg2_state_t   state;
258     picture_t       *p_pic;
259
260     block_t *p_block;
261
262     if( !pp_block || !*pp_block )
263         return NULL;
264
265     p_block = *pp_block;
266     if( p_block->i_flags & (BLOCK_FLAG_DISCONTINUITY | BLOCK_FLAG_CORRUPTED) )
267         Reset( p_dec );
268
269     while( 1 )
270     {
271         state = mpeg2_parse( p_sys->p_mpeg2dec );
272
273         switch( state )
274         {
275         case STATE_SEQUENCE:
276         {
277             /* */
278             DpbClean( p_dec );
279
280             /* */
281             mpeg2_custom_fbuf( p_sys->p_mpeg2dec, 1 );
282
283             /* Set the first 2 reference frames */
284             p_sys->i_sar_num = 0;
285             p_sys->i_sar_den = 0;
286             GetAR( p_dec );
287             for( int i = 0; i < 2; i++ )
288             {
289                 picture_t *p_picture = DpbNewPicture( p_dec );
290                 if( !p_picture )
291                 {
292                     Reset( p_dec );
293                     block_Release( p_block );
294                     return NULL;
295                 }
296                 PutPicture( p_dec, p_picture );
297             }
298
299             if( p_sys->p_synchro )
300                 decoder_SynchroRelease( p_sys->p_synchro );
301
302             if( p_sys->p_info->sequence->frame_period <= 0 )
303                 p_sys->p_synchro = NULL;
304             else
305                 p_sys->p_synchro =
306                 decoder_SynchroInit( p_dec, (uint32_t)(UINT64_C(1001000000) *
307                                 27 / p_sys->p_info->sequence->frame_period) );
308             p_sys->b_after_sequence_header = true;
309             break;
310         }
311
312         case STATE_GOP:
313             /* There can be userdata in a GOP. It needs to be remembered for the next picture. */
314             if( p_sys->p_info->user_data_len > 2 )
315             {
316                 free( p_sys->p_gop_user_data );
317                 p_sys->p_gop_user_data = calloc( p_sys->p_info->user_data_len, sizeof(uint8_t) );
318                 if( p_sys->p_gop_user_data )
319                 {
320                     p_sys->i_gop_user_data = p_sys->p_info->user_data_len;
321                     memcpy( p_sys->p_gop_user_data, p_sys->p_info->user_data, p_sys->p_info->user_data_len );
322                 }
323             }
324             break;
325
326         case STATE_PICTURE:
327         {
328             const mpeg2_info_t *p_info = p_sys->p_info;
329             const mpeg2_picture_t *p_current = p_info->current_picture;
330
331             mtime_t i_pts, i_dts;
332
333             if( p_sys->b_after_sequence_header &&
334                 (p_current->flags &
335                     PIC_MASK_CODING_TYPE) == PIC_FLAG_CODING_TYPE_P )
336             {
337                 /* Intra-slice refresh. Simulate a blank I picture. */
338                 msg_Dbg( p_dec, "intra-slice refresh stream" );
339                 decoder_SynchroNewPicture( p_sys->p_synchro,
340                                            I_CODING_TYPE, 2, 0, 0,
341                                            p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
342                 decoder_SynchroDecode( p_sys->p_synchro );
343                 decoder_SynchroEnd( p_sys->p_synchro, I_CODING_TYPE, 0 );
344                 p_sys->b_slice_i = true;
345             }
346             p_sys->b_after_sequence_header = false;
347
348 #ifdef PIC_FLAG_PTS
349             i_pts = p_current->flags & PIC_FLAG_PTS ?
350                 ( ( p_current->pts ==
351                     (uint32_t)p_sys->i_current_pts ) ?
352                   p_sys->i_current_pts : p_sys->i_previous_pts ) : 0;
353             i_dts = 0;
354
355             /* Hack to handle demuxers which only have DTS timestamps */
356             if( !i_pts && !p_block->i_pts && p_block->i_dts > 0 )
357             {
358                 if( p_info->sequence->flags & SEQ_FLAG_LOW_DELAY ||
359                     (p_current->flags &
360                       PIC_MASK_CODING_TYPE) == PIC_FLAG_CODING_TYPE_B )
361                 {
362                     i_pts = p_block->i_dts;
363                 }
364             }
365             p_block->i_pts = p_block->i_dts = 0;
366             /* End hack */
367
368 #else /* New interface */
369
370             i_pts = p_current->flags & PIC_FLAG_TAGS ?
371                 ( ( p_current->tag == (uint32_t)p_sys->i_current_pts ) ?
372                             p_sys->i_current_pts : p_sys->i_previous_pts ) : 0;
373             i_dts = p_current->flags & PIC_FLAG_TAGS ?
374                 ( ( p_current->tag2 == (uint32_t)p_sys->i_current_dts ) ?
375                             p_sys->i_current_dts : p_sys->i_previous_dts ) : 0;
376 #endif
377
378             /* If nb_fields == 1, it is a field picture, and it will be
379              * followed by another field picture for which we won't call
380              * decoder_SynchroNewPicture() because this would have other
381              * problems, so we take it into account here.
382              * This kind of sucks, but I didn't think better. --Meuuh
383              */
384             decoder_SynchroNewPicture( p_sys->p_synchro,
385                                        p_current->flags & PIC_MASK_CODING_TYPE,
386                                        p_current->nb_fields == 1 ? 2 :
387                                        p_current->nb_fields, i_pts, i_dts,
388                                        p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
389
390
391             bool b_skip = false;
392             if( !p_dec->b_pace_control && !p_sys->b_preroll &&
393                 !(p_sys->b_slice_i
394                    && ((p_current->flags
395                          & PIC_MASK_CODING_TYPE) == PIC_FLAG_CODING_TYPE_P))
396                    && !decoder_SynchroChoose( p_sys->p_synchro,
397                               p_current->flags
398                                 & PIC_MASK_CODING_TYPE,
399                               /*p_sys->p_vout->render_time*/ 0 /*FIXME*/,
400                               p_info->sequence->flags & SEQ_FLAG_LOW_DELAY ) )
401             {
402                 b_skip = true;
403             }
404
405             p_pic = NULL;
406             if( !b_skip )
407             {
408                 p_pic = DpbNewPicture( p_dec );
409                 if( !p_pic )
410                 {
411                     Reset( p_dec );
412
413                     p_pic = DpbNewPicture( p_dec );
414                     if( !p_pic )
415                     {
416                         mpeg2_reset( p_sys->p_mpeg2dec, 1 );
417                         block_Release( p_block );
418                         return NULL;
419                     }
420                 }
421             }
422
423             if( b_skip || !p_pic )
424             {
425                 mpeg2_skip( p_sys->p_mpeg2dec, 1 );
426                 p_sys->b_skip = true;
427                 decoder_SynchroTrash( p_sys->p_synchro );
428
429                 PutPicture( p_dec, NULL );
430
431                 if( !b_skip )
432                 {
433                     block_Release( p_block );
434                     return NULL;
435                 }
436             }
437             else
438             {
439                 mpeg2_skip( p_sys->p_mpeg2dec, 0 );
440                 p_sys->b_skip = false;
441                 decoder_SynchroDecode( p_sys->p_synchro );
442
443                 PutPicture( p_dec, p_pic );
444             }
445             if( p_info->user_data_len > 2 || p_sys->i_gop_user_data > 2 )
446             {
447                 p_sys->i_cc_pts = i_pts;
448                 p_sys->i_cc_dts = i_dts;
449                 if( (p_current->flags
450                              & PIC_MASK_CODING_TYPE) == PIC_FLAG_CODING_TYPE_P )
451                     p_sys->i_cc_flags = BLOCK_FLAG_TYPE_P;
452                 else if( (p_current->flags
453                              & PIC_MASK_CODING_TYPE) == PIC_FLAG_CODING_TYPE_B )
454                     p_sys->i_cc_flags = BLOCK_FLAG_TYPE_B;
455                 else p_sys->i_cc_flags = BLOCK_FLAG_TYPE_I;
456                 bool b_top_field_first = p_sys->p_info->current_picture->flags
457                                            & PIC_FLAG_TOP_FIELD_FIRST;
458
459                 if( p_sys->i_gop_user_data > 2 )
460                 {
461                     /* We now have picture info for any cached user_data out of the gop */
462                     cc_Extract( &p_sys->cc, b_top_field_first,
463                                 &p_sys->p_gop_user_data[0], p_sys->i_gop_user_data );
464                     p_sys->i_gop_user_data = 0;
465                 }
466
467                 /* Extract the CC from the user_data of the picture */
468                 if( p_info->user_data_len > 2 )
469                     cc_Extract( &p_sys->cc, b_top_field_first,
470                                 &p_info->user_data[0], p_info->user_data_len );
471             }
472         }
473         break;
474
475
476         case STATE_BUFFER:
477             if( !p_block->i_buffer )
478             {
479                 block_Release( p_block );
480                 return NULL;
481             }
482
483             if( (p_block->i_flags & (BLOCK_FLAG_DISCONTINUITY
484                                       | BLOCK_FLAG_CORRUPTED)) &&
485                 p_sys->p_synchro &&
486                 p_sys->p_info->sequence &&
487                 p_sys->p_info->sequence->width != (unsigned)-1 )
488             {
489                 decoder_SynchroReset( p_sys->p_synchro );
490                 if( p_sys->p_info->current_fbuf != NULL &&
491                     p_sys->p_info->current_fbuf->id != NULL )
492                 {
493                     p_sys->b_garbage_pic = true;
494                 }
495                 if( p_sys->b_slice_i )
496                 {
497                     decoder_SynchroNewPicture( p_sys->p_synchro,
498                                                I_CODING_TYPE, 2, 0, 0,
499                                                p_sys->p_info->sequence->flags &
500                                                             SEQ_FLAG_LOW_DELAY );
501                     decoder_SynchroDecode( p_sys->p_synchro );
502                     decoder_SynchroEnd( p_sys->p_synchro, I_CODING_TYPE, 0 );
503                 }
504             }
505
506             if( p_block->i_flags & BLOCK_FLAG_PREROLL )
507             {
508                 p_sys->b_preroll = true;
509             }
510             else if( p_sys->b_preroll )
511             {
512                 p_sys->b_preroll = false;
513                 if( p_sys->p_synchro )
514                     decoder_SynchroReset( p_sys->p_synchro );
515             }
516
517 #ifdef PIC_FLAG_PTS
518             if( p_block->i_pts )
519             {
520                 mpeg2_pts( p_sys->p_mpeg2dec, (uint32_t)p_block->i_pts );
521
522 #else /* New interface */
523             if( p_block->i_pts || p_block->i_dts )
524             {
525                 mpeg2_tag_picture( p_sys->p_mpeg2dec,
526                                    (uint32_t)p_block->i_pts,
527                                    (uint32_t)p_block->i_dts );
528 #endif
529                 p_sys->i_previous_pts = p_sys->i_current_pts;
530                 p_sys->i_current_pts = p_block->i_pts;
531                 p_sys->i_previous_dts = p_sys->i_current_dts;
532                 p_sys->i_current_dts = p_block->i_dts;
533             }
534
535             mpeg2_buffer( p_sys->p_mpeg2dec, p_block->p_buffer,
536                           p_block->p_buffer + p_block->i_buffer );
537
538             p_block->i_buffer = 0;
539             break;
540
541 #if MPEG2_RELEASE >= MPEG2_VERSION (0, 5, 0)
542
543         case STATE_SEQUENCE_MODIFIED:
544             GetAR( p_dec );
545             break;
546 #endif
547         case STATE_PICTURE_2ND:
548             p_sys->b_second_field = true;
549             break;
550
551
552         case STATE_INVALID_END:
553         case STATE_END:
554         case STATE_SLICE:
555             p_pic = NULL;
556             if( p_sys->p_info->display_fbuf &&
557                 p_sys->p_info->display_fbuf->id )
558             {
559                 p_pic = p_sys->p_info->display_fbuf->id;
560                 if( DpbDisplayPicture( p_dec, p_pic ) )
561                     p_pic = NULL;
562
563                 decoder_SynchroEnd( p_sys->p_synchro,
564                                     p_sys->p_info->display_picture->flags & PIC_MASK_CODING_TYPE,
565                                     p_sys->b_garbage_pic );
566
567                 if( p_pic )
568                 {
569                     p_pic->date = decoder_SynchroDate( p_sys->p_synchro );
570                     if( p_sys->b_garbage_pic )
571                         p_pic->date = 0; /* ??? */
572                     p_sys->b_garbage_pic = false;
573                 }
574             }
575
576             if( p_sys->p_info->discard_fbuf &&
577                 p_sys->p_info->discard_fbuf->id )
578             {
579                 DpbUnlinkPicture( p_dec, p_sys->p_info->discard_fbuf->id );
580             }
581
582             /* For still frames */
583             if( state == STATE_END && p_pic )
584                 p_pic->b_force = true;
585
586             if( p_pic )
587             {
588                 /* Avoid frames with identical timestamps.
589                  * Especially needed for still frames in DVD menus. */
590                 if( p_sys->i_last_frame_pts == p_pic->date )
591                     p_pic->date++;
592                 p_sys->i_last_frame_pts = p_pic->date;
593                 return p_pic;
594             }
595             break;
596
597         case STATE_INVALID:
598         {
599             msg_Err( p_dec, "invalid picture encountered" );
600             /* I don't think we have anything to do, but well without
601              * docs ... */
602             break;
603         }
604
605         default:
606             break;
607         }
608     }
609
610     /* Never reached */
611     return NULL;
612 }
613
614 /*****************************************************************************
615  * CloseDecoder: libmpeg2 decoder destruction
616  *****************************************************************************/
617 static void CloseDecoder( vlc_object_t *p_this )
618 {
619     decoder_t *p_dec = (decoder_t *)p_this;
620     decoder_sys_t *p_sys = p_dec->p_sys;
621
622     DpbClean( p_dec );
623
624     free( p_sys->p_gop_user_data );
625
626     if( p_sys->p_synchro ) decoder_SynchroRelease( p_sys->p_synchro );
627
628     if( p_sys->p_mpeg2dec ) mpeg2_close( p_sys->p_mpeg2dec );
629
630     free( p_sys );
631 }
632
633 /*****************************************************************************
634  * Reset: reset the decoder state
635  *****************************************************************************/
636 static void Reset( decoder_t *p_dec )
637 {
638     decoder_sys_t *p_sys = p_dec->p_sys;
639
640     cc_Flush( &p_sys->cc );
641     mpeg2_reset( p_sys->p_mpeg2dec, 0 );
642     DpbClean( p_dec );
643 }
644
645 /*****************************************************************************
646  * GetNewPicture: Get a new picture from the vout and set the buf struct
647  *****************************************************************************/
648 static picture_t *GetNewPicture( decoder_t *p_dec )
649 {
650     decoder_sys_t *p_sys = p_dec->p_sys;
651     picture_t *p_pic;
652
653     p_dec->fmt_out.video.i_width = p_sys->p_info->sequence->width;
654     p_dec->fmt_out.video.i_visible_width =
655         p_sys->p_info->sequence->picture_width;
656     p_dec->fmt_out.video.i_height = p_sys->p_info->sequence->height;
657     p_dec->fmt_out.video.i_visible_height =
658         p_sys->p_info->sequence->picture_height;
659     p_dec->fmt_out.video.i_sar_num = p_sys->i_sar_num;
660     p_dec->fmt_out.video.i_sar_den = p_sys->i_sar_den;
661
662     if( p_sys->p_info->sequence->frame_period > 0 )
663     {
664         p_dec->fmt_out.video.i_frame_rate =
665             (uint32_t)( (uint64_t)1001000000 * 27 /
666                         p_sys->p_info->sequence->frame_period );
667         p_dec->fmt_out.video.i_frame_rate_base = 1001;
668     }
669
670     p_dec->fmt_out.i_codec =
671         ( p_sys->p_info->sequence->chroma_height <
672           p_sys->p_info->sequence->height ) ?
673         VLC_CODEC_I420 : VLC_CODEC_I422;
674
675     /* Get a new picture */
676     p_pic = decoder_NewPicture( p_dec );
677
678     if( p_pic == NULL )
679         return NULL;
680
681     p_pic->b_progressive = p_sys->p_info->current_picture != NULL ?
682         p_sys->p_info->current_picture->flags & PIC_FLAG_PROGRESSIVE_FRAME : 1;
683     p_pic->b_top_field_first = p_sys->p_info->current_picture != NULL ?
684         p_sys->p_info->current_picture->flags & PIC_FLAG_TOP_FIELD_FIRST : 1;
685     p_pic->i_nb_fields = p_sys->p_info->current_picture != NULL ?
686         p_sys->p_info->current_picture->nb_fields : 2;
687
688     return p_pic;
689 }
690
691 #if MPEG2_RELEASE >= MPEG2_VERSION (0, 5, 0)
692 /*****************************************************************************
693  * GetCc: Retrieves the Closed Captions for the CC decoder.
694  *****************************************************************************/
695 static block_t *GetCc( decoder_t *p_dec, bool pb_present[4] )
696 {
697     decoder_sys_t   *p_sys = p_dec->p_sys;
698     block_t         *p_cc = NULL;
699     int i;
700
701     for( i = 0; i < 4; i++ )
702         pb_present[i] = p_sys->cc.pb_present[i];
703
704     if( p_sys->cc.i_data <= 0 )
705         return NULL;
706
707     p_cc = block_New( p_dec, p_sys->cc.i_data);
708     if( p_cc )
709     {
710         memcpy( p_cc->p_buffer, p_sys->cc.p_data, p_sys->cc.i_data );
711         p_cc->i_dts =
712         p_cc->i_pts = p_sys->cc.b_reorder ? p_sys->i_cc_pts : p_sys->i_cc_dts;
713         p_cc->i_flags = ( p_sys->cc.b_reorder  ? p_sys->i_cc_flags : BLOCK_FLAG_TYPE_P ) & ( BLOCK_FLAG_TYPE_I|BLOCK_FLAG_TYPE_P|BLOCK_FLAG_TYPE_B);
714     }
715     cc_Flush( &p_sys->cc );
716     return p_cc;
717 }
718 #endif
719
720 /*****************************************************************************
721  * GetAR: Get aspect ratio
722  *****************************************************************************/
723 static void GetAR( decoder_t *p_dec )
724 {
725     decoder_sys_t *p_sys = p_dec->p_sys;
726     int i_old_sar_num = p_sys->i_sar_num;
727     int i_old_sar_den = p_sys->i_sar_den;
728
729     /* Check whether the input gave a particular aspect ratio */
730     if( p_dec->fmt_in.video.i_sar_num > 0 &&
731         p_dec->fmt_in.video.i_sar_den > 0 )
732     {
733         p_sys->i_sar_num = p_dec->fmt_in.video.i_sar_num;
734         p_sys->i_sar_den = p_dec->fmt_in.video.i_sar_den;
735     }
736     else
737     {
738         /* Use the value provided in the MPEG sequence header */
739         if( p_sys->p_info->sequence->pixel_height > 0 )
740         {
741             p_sys->i_sar_num = p_sys->p_info->sequence->pixel_width;
742             p_sys->i_sar_den = p_sys->p_info->sequence->pixel_height;
743         }
744         else
745         {
746             /* Invalid aspect, assume 4:3.
747              * This shouldn't happen and if it does it is a bug
748              * in libmpeg2 (likely triggered by an invalid stream) */
749             p_sys->i_sar_num = p_sys->p_info->sequence->picture_height * 4;
750             p_sys->i_sar_den = p_sys->p_info->sequence->picture_width * 3;
751         }
752     }
753
754     if( p_sys->i_sar_num == i_old_sar_num &&
755         p_sys->i_sar_den == i_old_sar_den )
756         return;
757
758     if( p_sys->p_info->sequence->frame_period > 0 )
759         msg_Dbg( p_dec,
760                  "%dx%d (display %d,%d), sar %i:%i, %u.%03u fps",
761                  p_sys->p_info->sequence->picture_width,
762                  p_sys->p_info->sequence->picture_height,
763                  p_sys->p_info->sequence->display_width,
764                  p_sys->p_info->sequence->display_height,
765                  p_sys->i_sar_num, p_sys->i_sar_den,
766                  (uint32_t)((uint64_t)1001000000 * 27 /
767                      p_sys->p_info->sequence->frame_period / 1001),
768                  (uint32_t)((uint64_t)1001000000 * 27 /
769                      p_sys->p_info->sequence->frame_period % 1001) );
770     else
771         msg_Dbg( p_dec, "bad frame period" );
772 }
773
774 /*****************************************************************************
775  * PutPicture: Put a picture_t in mpeg2 context
776  *****************************************************************************/
777 static void PutPicture( decoder_t *p_dec, picture_t *p_picture )
778 {
779     decoder_sys_t *p_sys = p_dec->p_sys;
780
781     /* */
782     uint8_t *pp_buf[3];
783     for( int j = 0; j < 3; j++ )
784         pp_buf[j] = p_picture ? p_picture->p[j].p_pixels : NULL;
785     mpeg2_set_buf( p_sys->p_mpeg2dec, pp_buf, p_picture );
786
787     /* Completly broken API, why the hell does it suppose
788      * the stride of the chroma planes ! */
789     if( p_picture )
790         mpeg2_stride( p_sys->p_mpeg2dec, p_picture->p[Y_PLANE].i_pitch );
791 }
792
793
794 /**
795  * Initialize a virtual Decoded Picture Buffer to workaround
796  * libmpeg2 deficient API
797  */
798 static void DpbInit( decoder_t *p_dec )
799 {
800     decoder_sys_t *p_sys = p_dec->p_sys;
801
802     for( int i = 0; i < DPB_COUNT; i++ )
803         p_sys->p_dpb[i].p_picture = NULL;
804 }
805 /**
806  * Empty and reset the current DPB
807  */
808 static void DpbClean( decoder_t *p_dec )
809 {
810     decoder_sys_t *p_sys = p_dec->p_sys;
811
812     for( int i = 0; i < DPB_COUNT; i++ )
813     {
814         picture_dpb_t *p = &p_sys->p_dpb[i];
815         if( !p->p_picture )
816             continue;
817         if( p->b_linked )
818             decoder_UnlinkPicture( p_dec, p->p_picture );
819         if( !p->b_displayed )
820             decoder_DeletePicture( p_dec, p->p_picture );
821
822         p->p_picture = NULL;
823     }
824 }
825 /**
826  * Retreive a picture and reserve a place in the DPB
827  */
828 static picture_t *DpbNewPicture( decoder_t *p_dec )
829 {
830     decoder_sys_t *p_sys = p_dec->p_sys;
831
832     picture_dpb_t *p;
833     int i;
834
835     for( i = 0; i < DPB_COUNT; i++ )
836     {
837         p = &p_sys->p_dpb[i];
838         if( !p->p_picture )
839             break;
840     }
841     if( i >= DPB_COUNT )
842     {
843         msg_Err( p_dec, "Leaking picture" );
844         return NULL;
845     }
846
847     p->p_picture = GetNewPicture( p_dec );
848     if( p->p_picture )
849     {
850         decoder_LinkPicture( p_dec, p->p_picture );
851         p->b_linked = true;
852         p->b_displayed = false;
853
854         p->p_picture->date = 0;
855     }
856     return p->p_picture;
857 }
858 static picture_dpb_t *DpbFindPicture( decoder_t *p_dec, picture_t *p_picture )
859 {
860     decoder_sys_t *p_sys = p_dec->p_sys;
861
862     for( int i = 0; i < DPB_COUNT; i++ )
863     {
864         picture_dpb_t *p = &p_sys->p_dpb[i];
865         if( p->p_picture == p_picture )
866             return p;
867     }
868     return NULL;
869 }
870 /**
871  * Unlink the provided picture and ensure that the decoder
872  * does not own it anymore.
873  */
874 static void DpbUnlinkPicture( decoder_t *p_dec, picture_t *p_picture )
875 {
876     picture_dpb_t *p = DpbFindPicture( p_dec, p_picture );
877
878     /* XXX it is needed to workaround libmpeg2 bugs */
879     if( !p || !p->b_linked )
880     {
881         msg_Err( p_dec, "DpbUnlinkPicture called on an invalid picture" );
882         return;
883     }
884
885     assert( p && p->b_linked );
886
887     decoder_UnlinkPicture( p_dec, p->p_picture );
888     p->b_linked = false;
889
890     if( !p->b_displayed )
891         decoder_DeletePicture( p_dec, p->p_picture );
892     p->p_picture = NULL;
893 }
894 /**
895  * Mark the provided picture as displayed.
896  */
897 static int DpbDisplayPicture( decoder_t *p_dec, picture_t *p_picture )
898 {
899     picture_dpb_t *p = DpbFindPicture( p_dec, p_picture );
900
901     /* XXX it is needed to workaround libmpeg2 bugs */
902     if( !p || p->b_displayed || !p->b_linked )
903     {
904         msg_Err( p_dec, "DpbDisplayPicture called on an invalid picture" );
905         return VLC_EGENERIC;
906     }
907
908     assert( p && !p->b_displayed && p->b_linked );
909
910     p->b_displayed = true;
911     return VLC_SUCCESS;
912 }
913
914