]> git.sesse.net Git - vlc/blob - modules/codec/libmpeg2.c
Support for UDP-Lite (with full checksum coverage only atm)
[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 #include <vlc/vlc.h>
29 #include <vlc_vout.h>
30 #include <vlc_codec.h>
31
32 #include <mpeg2dec/mpeg2.h>
33
34 #include <vlc_vout_synchro.h>
35
36 /* Aspect ratio (ISO/IEC 13818-2 section 6.3.3, table 6-3) */
37 #define AR_SQUARE_PICTURE       1                           /* square pixels */
38 #define AR_4_3_PICTURE          2                        /* 4:3 picture (TV) */
39 #define AR_16_9_PICTURE         3              /* 16:9 picture (wide screen) */
40 #define AR_221_1_PICTURE        4                  /* 2.21:1 picture (movie) */
41
42 /*****************************************************************************
43  * decoder_sys_t : libmpeg2 decoder descriptor
44  *****************************************************************************/
45 struct decoder_sys_t
46 {
47     /*
48      * libmpeg2 properties
49      */
50     mpeg2dec_t          *p_mpeg2dec;
51     const mpeg2_info_t  *p_info;
52     vlc_bool_t          b_skip;
53
54     /*
55      * Input properties
56      */
57     mtime_t          i_previous_pts;
58     mtime_t          i_current_pts;
59     mtime_t          i_previous_dts;
60     mtime_t          i_current_dts;
61     int              i_current_rate;
62     picture_t *      p_picture_to_destroy;
63     vlc_bool_t       b_garbage_pic;
64     vlc_bool_t       b_after_sequence_header; /* is it the next frame after
65                                                * the sequence header ?    */
66     vlc_bool_t       b_slice_i;             /* intra-slice refresh stream */
67     vlc_bool_t       b_second_field;
68
69     vlc_bool_t       b_preroll;
70
71     /*
72      * Output properties
73      */
74     vout_synchro_t *p_synchro;
75     int            i_aspect;
76     int            i_sar_num;
77     int            i_sar_den;
78     mtime_t        i_last_frame_pts;
79
80 };
81
82 /*****************************************************************************
83  * Local prototypes
84  *****************************************************************************/
85 static int  OpenDecoder( vlc_object_t * );
86 static void CloseDecoder( vlc_object_t * );
87
88 static picture_t *DecodeBlock( decoder_t *, block_t ** );
89
90 static picture_t *GetNewPicture( decoder_t *, uint8_t ** );
91 static void GetAR( decoder_t *p_dec );
92
93 /*****************************************************************************
94  * Module descriptor
95  *****************************************************************************/
96 vlc_module_begin();
97     set_description( _("MPEG I/II video decoder (using libmpeg2)") );
98     set_capability( "decoder", 150 );
99     set_category( CAT_INPUT );
100     set_subcategory( SUBCAT_INPUT_VCODEC );
101     set_callbacks( OpenDecoder, CloseDecoder );
102     add_shortcut( "libmpeg2" );
103 vlc_module_end();
104
105 /*****************************************************************************
106  * OpenDecoder: probe the decoder and return score
107  *****************************************************************************/
108 static int OpenDecoder( vlc_object_t *p_this )
109 {
110     decoder_t *p_dec = (decoder_t*)p_this;
111     decoder_sys_t *p_sys;
112     uint32_t i_accel = 0;
113
114     if( p_dec->fmt_in.i_codec != VLC_FOURCC('m','p','g','v') &&
115         p_dec->fmt_in.i_codec != VLC_FOURCC('m','p','g','1') &&
116         /* Pinnacle hardware-mpeg1 */
117         p_dec->fmt_in.i_codec != VLC_FOURCC('P','I','M','1') &&
118         /* ATI Video */
119         p_dec->fmt_in.i_codec != VLC_FOURCC('m','p','2','v') &&
120         p_dec->fmt_in.i_codec != VLC_FOURCC('m','p','g','2') &&
121         p_dec->fmt_in.i_codec != VLC_FOURCC('h','d','v','2') )
122     {
123         return VLC_EGENERIC;
124     }
125
126     /* Allocate the memory needed to store the decoder's structure */
127     if( ( p_dec->p_sys = p_sys =
128           (decoder_sys_t *)malloc(sizeof(decoder_sys_t)) ) == NULL )
129     {
130         msg_Err( p_dec, "out of memory" );
131         return VLC_EGENERIC;
132     }
133
134     /* Initialize the thread properties */
135     memset( p_sys, 0, sizeof(decoder_sys_t) );
136     p_sys->p_mpeg2dec = NULL;
137     p_sys->p_synchro  = NULL;
138     p_sys->p_info     = NULL;
139     p_sys->i_current_pts  = 0;
140     p_sys->i_previous_pts = 0;
141     p_sys->i_current_dts  = 0;
142     p_sys->i_previous_dts = 0;
143     p_sys->p_picture_to_destroy = NULL;
144     p_sys->b_garbage_pic = 0;
145     p_sys->b_slice_i  = 0;
146     p_sys->b_second_field = 0;
147     p_sys->b_skip     = 0;
148     p_sys->b_preroll = VLC_FALSE;
149
150 #if defined( __i386__ ) || defined( __x86_64__ )
151     if( vlc_CPU() & CPU_CAPABILITY_MMX )
152     {
153         i_accel |= MPEG2_ACCEL_X86_MMX;
154     }
155
156     if( vlc_CPU() & CPU_CAPABILITY_3DNOW )
157     {
158         i_accel |= MPEG2_ACCEL_X86_3DNOW;
159     }
160
161     if( vlc_CPU() & CPU_CAPABILITY_MMXEXT )
162     {
163         i_accel |= MPEG2_ACCEL_X86_MMXEXT;
164     }
165
166 #elif defined( __powerpc__ ) || defined( __ppc__ ) || defined( __ppc64__ )
167     if( vlc_CPU() & CPU_CAPABILITY_ALTIVEC )
168     {
169         i_accel |= MPEG2_ACCEL_PPC_ALTIVEC;
170     }
171
172 #else
173     /* If we do not know this CPU, trust libmpeg2's feature detection */
174     i_accel = MPEG2_ACCEL_DETECT;
175
176 #endif
177
178     /* Set CPU acceleration features */
179     mpeg2_accel( i_accel );
180
181     /* Initialize decoder */
182     p_sys->p_mpeg2dec = mpeg2_init();
183     if( p_sys->p_mpeg2dec == NULL)
184     {
185         msg_Err( p_dec, "mpeg2_init() failed" );
186         free( p_sys );
187         return VLC_EGENERIC;
188     }
189
190     p_sys->p_info = mpeg2_info( p_sys->p_mpeg2dec );
191
192     p_dec->pf_decode_video = DecodeBlock;
193
194     return VLC_SUCCESS;
195 }
196
197 /*****************************************************************************
198  * RunDecoder: the libmpeg2 decoder
199  *****************************************************************************/
200 static picture_t *DecodeBlock( decoder_t *p_dec, block_t **pp_block )
201 {
202     decoder_sys_t   *p_sys = p_dec->p_sys;
203     mpeg2_state_t   state;
204     picture_t       *p_pic;
205
206     block_t *p_block;
207
208     if( !pp_block || !*pp_block ) return NULL;
209
210     p_block = *pp_block;
211
212     while( 1 )
213     {
214         state = mpeg2_parse( p_sys->p_mpeg2dec );
215
216         switch( state )
217         {
218         case STATE_BUFFER:
219             if( !p_block->i_buffer )
220             {
221                 block_Release( p_block );
222                 return NULL;
223             }
224
225             if( (p_block->i_flags & (BLOCK_FLAG_DISCONTINUITY
226                                       | BLOCK_FLAG_CORRUPTED)) &&
227                 p_sys->p_synchro &&
228                 p_sys->p_info->sequence &&
229                 p_sys->p_info->sequence->width != (unsigned)-1 )
230             {
231                 vout_SynchroReset( p_sys->p_synchro );
232                 if( p_sys->p_info->current_fbuf != NULL
233                     && p_sys->p_info->current_fbuf->id != NULL )
234                 {
235                     p_sys->b_garbage_pic = 1;
236                     p_pic = p_sys->p_info->current_fbuf->id;
237                 }
238                 else
239                 {
240                     uint8_t *buf[3];
241                     buf[0] = buf[1] = buf[2] = NULL;
242                     if( (p_pic = GetNewPicture( p_dec, buf )) == NULL )
243                         break;
244                     mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
245                     mpeg2_stride( p_sys->p_mpeg2dec, p_pic->p[Y_PLANE].i_pitch );
246                 }
247                 p_sys->p_picture_to_destroy = p_pic;
248
249                 if ( p_sys->b_slice_i )
250                 {
251                     vout_SynchroNewPicture( p_sys->p_synchro,
252                         I_CODING_TYPE, 2, 0, 0, p_sys->i_current_rate,
253                         p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
254                     vout_SynchroDecode( p_sys->p_synchro );
255                     vout_SynchroEnd( p_sys->p_synchro, I_CODING_TYPE, 0 );
256                 }
257             }
258
259             if( p_block->i_flags & BLOCK_FLAG_PREROLL )
260             {
261                 p_sys->b_preroll = VLC_TRUE;
262             }
263             else if( p_sys->b_preroll )
264             {
265                 p_sys->b_preroll = VLC_FALSE;
266                 /* Reset synchro */
267                 vout_SynchroReset( p_sys->p_synchro );
268             }
269
270 #ifdef PIC_FLAG_PTS
271             if( p_block->i_pts )
272             {
273                 mpeg2_pts( p_sys->p_mpeg2dec, (uint32_t)p_block->i_pts );
274
275 #else /* New interface */
276             if( p_block->i_pts || p_block->i_dts )
277             {
278                 mpeg2_tag_picture( p_sys->p_mpeg2dec,
279                                    (uint32_t)p_block->i_pts,
280                                    (uint32_t)p_block->i_dts );
281 #endif
282                 p_sys->i_previous_pts = p_sys->i_current_pts;
283                 p_sys->i_current_pts = p_block->i_pts;
284                 p_sys->i_previous_dts = p_sys->i_current_dts;
285                 p_sys->i_current_dts = p_block->i_dts;
286             }
287
288             p_sys->i_current_rate = p_block->i_rate;
289
290             mpeg2_buffer( p_sys->p_mpeg2dec, p_block->p_buffer,
291                           p_block->p_buffer + p_block->i_buffer );
292
293             p_block->i_buffer = 0;
294             break;
295
296 #ifdef STATE_SEQUENCE_MODIFIED
297 /* FIXME - the above ifdef is always FALSE, even with libmpeg2-0.5.0
298  * Need to improve the implementation to avoid invalid/unref pictures */
299
300         case STATE_SEQUENCE_MODIFIED:
301             GetAR( p_dec );
302             break;
303 #endif
304
305         case STATE_SEQUENCE:
306         {
307             /* Initialize video output */
308             uint8_t *buf[3];
309             buf[0] = buf[1] = buf[2] = NULL;
310
311             GetAR( p_dec );
312
313             mpeg2_custom_fbuf( p_sys->p_mpeg2dec, 1 );
314
315             /* Set the first 2 reference frames */
316             mpeg2_set_buf( p_sys->p_mpeg2dec, buf, NULL );
317
318             if( (p_pic = GetNewPicture( p_dec, buf )) == NULL )
319             {
320                 block_Release( p_block );
321                 return NULL;
322             }
323
324             mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
325             mpeg2_stride( p_sys->p_mpeg2dec, p_pic->p[Y_PLANE].i_pitch );
326
327             /* This picture will never go through display_picture. */
328             p_pic->date = 0;
329
330             /* For some reason, libmpeg2 will put this pic twice in
331              * discard_picture. This can be considered a bug in libmpeg2. */
332             p_dec->pf_picture_link( p_dec, p_pic );
333
334             if( p_sys->p_synchro )
335             {
336                 vout_SynchroRelease( p_sys->p_synchro );
337             }
338             p_sys->p_synchro = vout_SynchroInit( p_dec,
339                 (uint32_t)((uint64_t)1001000000 * 27 /
340                 p_sys->p_info->sequence->frame_period) );
341             p_sys->b_after_sequence_header = 1;
342         }
343         break;
344
345         case STATE_PICTURE_2ND:
346             p_sys->b_second_field = 1;
347             break;
348
349         case STATE_PICTURE:
350         {
351             uint8_t *buf[3];
352             mtime_t i_pts, i_dts;
353             buf[0] = buf[1] = buf[2] = NULL;
354
355             if ( p_sys->b_after_sequence_header &&
356                  ((p_sys->p_info->current_picture->flags &
357                        PIC_MASK_CODING_TYPE) == PIC_FLAG_CODING_TYPE_P) )
358             {
359                 /* Intra-slice refresh. Simulate a blank I picture. */
360                 msg_Dbg( p_dec, "intra-slice refresh stream" );
361                 vout_SynchroNewPicture( p_sys->p_synchro,
362                     I_CODING_TYPE, 2, 0, 0, p_sys->i_current_rate,
363                     p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
364                 vout_SynchroDecode( p_sys->p_synchro );
365                 vout_SynchroEnd( p_sys->p_synchro, I_CODING_TYPE, 0 );
366                 p_sys->b_slice_i = 1;
367             }
368             p_sys->b_after_sequence_header = 0;
369
370 #ifdef PIC_FLAG_PTS
371             i_pts = p_sys->p_info->current_picture->flags & PIC_FLAG_PTS ?
372                 ( ( p_sys->p_info->current_picture->pts ==
373                     (uint32_t)p_sys->i_current_pts ) ?
374                   p_sys->i_current_pts : p_sys->i_previous_pts ) : 0;
375             i_dts = 0;
376
377             /* Hack to handle demuxers which only have DTS timestamps */
378             if( !i_pts && !p_block->i_pts && p_block->i_dts > 0 )
379             {
380                 if( p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY ||
381                     (p_sys->p_info->current_picture->flags &
382                       PIC_MASK_CODING_TYPE) == PIC_FLAG_CODING_TYPE_B )
383                 {
384                     i_pts = p_block->i_dts;
385                 }
386             }
387             p_block->i_pts = p_block->i_dts = 0;
388             /* End hack */
389
390 #else /* New interface */
391
392             i_pts = p_sys->p_info->current_picture->flags & PIC_FLAG_TAGS ?
393                 ( ( p_sys->p_info->current_picture->tag ==
394                     (uint32_t)p_sys->i_current_pts ) ?
395                   p_sys->i_current_pts : p_sys->i_previous_pts ) : 0;
396             i_dts = p_sys->p_info->current_picture->flags & PIC_FLAG_TAGS ?
397                 ( ( p_sys->p_info->current_picture->tag2 ==
398                     (uint32_t)p_sys->i_current_dts ) ?
399                   p_sys->i_current_dts : p_sys->i_previous_dts ) : 0;
400 #endif
401
402             /* If nb_fields == 1, it is a field picture, and it will be
403              * followed by another field picture for which we won't call
404              * vout_SynchroNewPicture() because this would have other 
405              * problems, so we take it into account here.
406              * This kind of sucks, but I didn't think better. --Meuuh
407              */
408             vout_SynchroNewPicture( p_sys->p_synchro,
409                 p_sys->p_info->current_picture->flags & PIC_MASK_CODING_TYPE,
410                 p_sys->p_info->current_picture->nb_fields == 1 ? 2 :
411                 p_sys->p_info->current_picture->nb_fields, i_pts, i_dts,
412                 p_sys->i_current_rate,
413                 p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
414
415             if( !p_dec->b_pace_control && !p_sys->b_preroll &&
416                 !(p_sys->b_slice_i
417                    && ((p_sys->p_info->current_picture->flags
418                          & PIC_MASK_CODING_TYPE) == P_CODING_TYPE))
419                    && !vout_SynchroChoose( p_sys->p_synchro,
420                               p_sys->p_info->current_picture->flags
421                                 & PIC_MASK_CODING_TYPE,
422                               /*p_sys->p_vout->render_time*/ 0 /*FIXME*/,
423                               p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY ) )
424             {
425                 mpeg2_skip( p_sys->p_mpeg2dec, 1 );
426                 p_sys->b_skip = 1;
427                 vout_SynchroTrash( p_sys->p_synchro );
428                 mpeg2_set_buf( p_sys->p_mpeg2dec, buf, NULL );
429             }
430             else
431             {
432                 mpeg2_skip( p_sys->p_mpeg2dec, 0 );
433                 p_sys->b_skip = 0;
434                 vout_SynchroDecode( p_sys->p_synchro );
435
436                 if( (p_pic = GetNewPicture( p_dec, buf )) == NULL )
437                 {
438                     block_Release( p_block );
439                     return NULL;
440                 }
441
442                 mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
443                 mpeg2_stride( p_sys->p_mpeg2dec, p_pic->p[Y_PLANE].i_pitch );
444             }
445         }
446         break;
447
448         case STATE_END:
449         case STATE_SLICE:
450             p_pic = NULL;
451             if( p_sys->p_info->display_fbuf
452                 && p_sys->p_info->display_fbuf->id )
453             {
454                 p_pic = (picture_t *)p_sys->p_info->display_fbuf->id;
455
456                 vout_SynchroEnd( p_sys->p_synchro,
457                             p_sys->p_info->display_picture->flags
458                              & PIC_MASK_CODING_TYPE,
459                             p_sys->b_garbage_pic );
460                 p_sys->b_garbage_pic = 0;
461
462                 if ( p_sys->p_picture_to_destroy != p_pic )
463                 {
464                     p_pic->date = vout_SynchroDate( p_sys->p_synchro );
465                 }
466                 else
467                 {
468                     p_sys->p_picture_to_destroy = NULL;
469                     p_pic->date = 0;
470                 }
471             }
472
473             if( p_sys->p_info->discard_fbuf &&
474                 p_sys->p_info->discard_fbuf->id )
475             {
476                 p_dec->pf_picture_unlink( p_dec,
477                                           p_sys->p_info->discard_fbuf->id );
478             }
479
480             /* For still frames */
481             if( state == STATE_END && p_pic ) p_pic->b_force = VLC_TRUE;
482
483             if( p_pic )
484             {
485                 /* Avoid frames with identical timestamps.
486                  * Especially needed for still frames in DVD menus. */
487                 if( p_sys->i_last_frame_pts == p_pic->date ) p_pic->date++;
488                 p_sys->i_last_frame_pts = p_pic->date;
489
490                 return p_pic;
491             }
492
493             break;
494
495         case STATE_INVALID:
496         {
497             uint8_t *buf[3];
498             buf[0] = buf[1] = buf[2] = NULL;
499
500             msg_Warn( p_dec, "invalid picture encountered" );
501             if ( ( p_sys->p_info->current_picture == NULL ) ||
502                ( ( p_sys->p_info->current_picture->flags &
503                    PIC_MASK_CODING_TYPE) != B_CODING_TYPE ) )
504             {
505                 if( p_sys->p_synchro ) vout_SynchroReset( p_sys->p_synchro );
506             }
507             mpeg2_skip( p_sys->p_mpeg2dec, 1 );
508             p_sys->b_skip = 1;
509
510             if( p_sys->p_info->current_fbuf &&
511                 p_sys->p_info->current_fbuf->id )
512             {
513                 p_sys->b_garbage_pic = 1;
514                 p_pic = p_sys->p_info->current_fbuf->id;
515             }
516             else if( !p_sys->p_info->sequence )
517             {
518                 break;
519             }
520             else
521             {
522                 if( (p_pic = GetNewPicture( p_dec, buf )) == NULL )
523                     break;
524                 mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
525                 mpeg2_stride( p_sys->p_mpeg2dec, p_pic->p[Y_PLANE].i_pitch );
526             }
527             p_sys->p_picture_to_destroy = p_pic;
528
529             memset( p_pic->p[0].p_pixels, 0,
530                     p_sys->p_info->sequence->width
531                      * p_sys->p_info->sequence->height );
532             memset( p_pic->p[1].p_pixels, 0x80,
533                     p_sys->p_info->sequence->width
534                      * p_sys->p_info->sequence->height / 4 );
535             memset( p_pic->p[2].p_pixels, 0x80,
536                     p_sys->p_info->sequence->width
537                      * p_sys->p_info->sequence->height / 4 );
538
539             if( p_sys->b_slice_i )
540             {
541                 vout_SynchroNewPicture( p_sys->p_synchro,
542                         I_CODING_TYPE, 2, 0, 0, p_sys->i_current_rate,
543                         p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
544                 vout_SynchroDecode( p_sys->p_synchro );
545                 vout_SynchroEnd( p_sys->p_synchro, I_CODING_TYPE, 0 );
546             }
547             break;
548         }
549
550         default:
551             break;
552         }
553     }
554
555     /* Never reached */
556     return NULL;
557 }
558
559 /*****************************************************************************
560  * CloseDecoder: libmpeg2 decoder destruction
561  *****************************************************************************/
562 static void CloseDecoder( vlc_object_t *p_this )
563 {
564     decoder_t *p_dec = (decoder_t *)p_this;
565     decoder_sys_t *p_sys = p_dec->p_sys;
566
567     if( p_sys->p_synchro ) vout_SynchroRelease( p_sys->p_synchro );
568
569     if( p_sys->p_mpeg2dec ) mpeg2_close( p_sys->p_mpeg2dec );
570
571     free( p_sys );
572 }
573
574 /*****************************************************************************
575  * GetNewPicture: Get a new picture from the vout and set the buf struct
576  *****************************************************************************/
577 static picture_t *GetNewPicture( decoder_t *p_dec, uint8_t **pp_buf )
578 {
579     decoder_sys_t *p_sys = p_dec->p_sys;
580     picture_t *p_pic;
581
582     p_dec->fmt_out.video.i_width = p_sys->p_info->sequence->width;
583     p_dec->fmt_out.video.i_visible_width =
584         p_sys->p_info->sequence->picture_width;
585     p_dec->fmt_out.video.i_height = p_sys->p_info->sequence->height;
586     p_dec->fmt_out.video.i_visible_height =
587         p_sys->p_info->sequence->picture_height;
588     p_dec->fmt_out.video.i_aspect = p_sys->i_aspect;
589     p_dec->fmt_out.video.i_sar_num = p_sys->i_sar_num;
590     p_dec->fmt_out.video.i_sar_den = p_sys->i_sar_den;
591
592     if( p_sys->p_info->sequence->frame_period > 0 )
593     {
594         p_dec->fmt_out.video.i_frame_rate =
595             (uint32_t)( (uint64_t)1001000000 * 27 /
596                         p_sys->p_info->sequence->frame_period );
597         p_dec->fmt_out.video.i_frame_rate_base = 1001;
598     }
599
600     p_dec->fmt_out.i_codec =
601         ( p_sys->p_info->sequence->chroma_height <
602           p_sys->p_info->sequence->height ) ?
603         VLC_FOURCC('I','4','2','0') : VLC_FOURCC('I','4','2','2');
604
605     /* Get a new picture */
606     p_pic = p_dec->pf_vout_buffer_new( p_dec );
607
608     if( p_pic == NULL ) return NULL;
609
610     p_pic->b_progressive = p_sys->p_info->current_picture != NULL ?
611         p_sys->p_info->current_picture->flags & PIC_FLAG_PROGRESSIVE_FRAME : 1;
612     p_pic->b_top_field_first = p_sys->p_info->current_picture != NULL ?
613         p_sys->p_info->current_picture->flags & PIC_FLAG_TOP_FIELD_FIRST : 1;
614     p_pic->i_nb_fields = p_sys->p_info->current_picture != NULL ?
615         p_sys->p_info->current_picture->nb_fields : 2;
616
617     p_dec->pf_picture_link( p_dec, p_pic );
618
619     pp_buf[0] = p_pic->p[0].p_pixels;
620     pp_buf[1] = p_pic->p[1].p_pixels;
621     pp_buf[2] = p_pic->p[2].p_pixels;
622
623     return p_pic;
624 }
625
626 /*****************************************************************************
627  * GetAR: Get aspect ratio
628  *****************************************************************************/
629 static void GetAR( decoder_t *p_dec )
630 {
631     decoder_sys_t *p_sys = p_dec->p_sys;
632
633     /* Check whether the input gave a particular aspect ratio */
634     if( p_dec->fmt_in.video.i_aspect )
635     {
636         p_sys->i_aspect = p_dec->fmt_in.video.i_aspect;
637         if( p_sys->i_aspect <= AR_221_1_PICTURE )
638         switch( p_sys->i_aspect )
639         {
640         case AR_4_3_PICTURE:
641             p_sys->i_aspect = VOUT_ASPECT_FACTOR * 4 / 3;
642             p_sys->i_sar_num = p_sys->p_info->sequence->picture_height * 4;
643             p_sys->i_sar_den = p_sys->p_info->sequence->picture_width * 3;
644             break;
645         case AR_16_9_PICTURE:
646             p_sys->i_aspect = VOUT_ASPECT_FACTOR * 16 / 9;
647             p_sys->i_sar_num = p_sys->p_info->sequence->picture_height * 16;
648             p_sys->i_sar_den = p_sys->p_info->sequence->picture_width * 9;
649             break;
650         case AR_221_1_PICTURE:
651             p_sys->i_aspect = VOUT_ASPECT_FACTOR * 221 / 100;
652             p_sys->i_sar_num = p_sys->p_info->sequence->picture_height * 221;
653             p_sys->i_sar_den = p_sys->p_info->sequence->picture_width * 100;
654             break;
655         case AR_SQUARE_PICTURE:
656             p_sys->i_aspect = VOUT_ASPECT_FACTOR *
657                            p_sys->p_info->sequence->picture_width /
658                            p_sys->p_info->sequence->picture_height;
659             p_sys->i_sar_num = p_sys->i_sar_den = 1;
660             break;
661         }
662     }
663     else
664     {
665         /* Use the value provided in the MPEG sequence header */
666         if( p_sys->p_info->sequence->pixel_height > 0 )
667         {
668             p_sys->i_aspect =
669                 ((uint64_t)p_sys->p_info->sequence->picture_width) *
670                 p_sys->p_info->sequence->pixel_width *
671                 VOUT_ASPECT_FACTOR /
672                 p_sys->p_info->sequence->picture_height /
673                 p_sys->p_info->sequence->pixel_height;
674             p_sys->i_sar_num = p_sys->p_info->sequence->pixel_width;
675             p_sys->i_sar_den = p_sys->p_info->sequence->pixel_height;
676         }
677         else
678         {
679             /* Invalid aspect, assume 4:3.
680              * This shouldn't happen and if it does it is a bug
681              * in libmpeg2 (likely triggered by an invalid stream) */
682             p_sys->i_aspect = VOUT_ASPECT_FACTOR * 4 / 3;
683             p_sys->i_sar_num = p_sys->p_info->sequence->picture_height * 4;
684             p_sys->i_sar_den = p_sys->p_info->sequence->picture_width * 3;
685         }
686     }
687
688     msg_Dbg( p_dec, "%dx%d (display %d,%d), aspect %d, sar %i:%i, %u.%03u fps",
689              p_sys->p_info->sequence->picture_width,
690              p_sys->p_info->sequence->picture_height,
691              p_sys->p_info->sequence->display_width,
692              p_sys->p_info->sequence->display_height,
693              p_sys->i_aspect, p_sys->i_sar_num, p_sys->i_sar_den,
694              (uint32_t)((uint64_t)1001000000 * 27 /
695                  p_sys->p_info->sequence->frame_period / 1001),
696              (uint32_t)((uint64_t)1001000000 * 27 /
697                  p_sys->p_info->sequence->frame_period % 1001) );
698 }