]> git.sesse.net Git - vlc/blob - modules/packetizer/h264.c
* modules/packetizer/h264.c: insert an SPS and PPS before each keyframe.
[vlc] / modules / packetizer / h264.c
1 /*****************************************************************************
2  * h264.c: h264/avc video packetizer
3  *****************************************************************************
4  * Copyright (C) 2001, 2002, 2006 the VideoLAN team
5  * $Id$
6  *
7  * Authors: Laurent Aimar <fenrir@via.ecp.fr>
8  *          Eric Petit <titer@videolan.org>
9  *          Gildas Bazin <gbazin@videolan.org>
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or
14  * (at your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19  * GNU General Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public License
22  * along with this program; if not, write to the Free Software
23  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
24  *****************************************************************************/
25
26 /*****************************************************************************
27  * Preamble
28  *****************************************************************************/
29 #include <stdlib.h>                                      /* malloc(), free() */
30
31 #include <vlc/vlc.h>
32 #include <vlc/decoder.h>
33 #include <vlc/sout.h>
34
35 #include "vlc_block_helper.h"
36 #include "vlc_bits.h"
37
38 /*****************************************************************************
39  * Module descriptor
40  *****************************************************************************/
41 static int  Open ( vlc_object_t * );
42 static void Close( vlc_object_t * );
43
44 vlc_module_begin();
45     set_category( CAT_SOUT );
46     set_subcategory( SUBCAT_SOUT_PACKETIZER );
47     set_description( _("H.264 video packetizer") );
48     set_capability( "packetizer", 50 );
49     set_callbacks( Open, Close );
50 vlc_module_end();
51
52
53 /****************************************************************************
54  * Local prototypes
55  ****************************************************************************/
56 static block_t *Packetize( decoder_t *, block_t ** );
57 static block_t *PacketizeAVC1( decoder_t *, block_t ** );
58
59 struct decoder_sys_t
60 {
61     block_bytestream_t bytestream;
62
63     int     i_state;
64     int     i_offset;
65     uint8_t startcode[4];
66
67     vlc_bool_t b_slice;
68     block_t    *p_frame;
69
70     vlc_bool_t   b_sps;
71     vlc_bool_t   b_pps;
72
73     /* avcC data */
74     int i_avcC_length_size;
75     block_t *p_sps;
76     block_t *p_pps;
77
78     /* Useful values of the Sequence Parameter Set */
79     int i_log2_max_frame_num;
80     int b_frame_mbs_only;
81
82     /* Useful values of the Slice Header */
83     int i_nal_type;
84     int i_nal_ref_idc;
85     int i_idr_pic_id;
86     int i_frame_num;
87 };
88
89 enum
90 {
91     STATE_NOSYNC,
92     STATE_NEXT_SYNC,
93 };
94
95 enum nal_unit_type_e
96 {
97     NAL_UNKNOWN = 0,
98     NAL_SLICE   = 1,
99     NAL_SLICE_DPA   = 2,
100     NAL_SLICE_DPB   = 3,
101     NAL_SLICE_DPC   = 4,
102     NAL_SLICE_IDR   = 5,    /* ref_idc != 0 */
103     NAL_SEI         = 6,    /* ref_idc == 0 */
104     NAL_SPS         = 7,
105     NAL_PPS         = 8,
106     NAL_AU_DELIMITER= 9
107     /* ref_idc == 0 for 6,9,10,11,12 */
108 };
109
110 enum nal_priority_e
111 {
112     NAL_PRIORITY_DISPOSABLE = 0,
113     NAL_PRIORITY_LOW        = 1,
114     NAL_PRIORITY_HIGH       = 2,
115     NAL_PRIORITY_HIGHEST    = 3,
116 };
117
118 static block_t *ParseNALBlock( decoder_t *, block_t * );
119
120 static block_t *nal_get_annexeb( decoder_t *, uint8_t *p, int );
121
122 /*****************************************************************************
123  * Open: probe the packetizer and return score
124  * When opening after demux, the packetizer is only loaded AFTER the decoder
125  * That means that what you set in fmt_out is ignored by the decoder in this special case
126  *****************************************************************************/
127 static int Open( vlc_object_t *p_this )
128 {
129     decoder_t     *p_dec = (decoder_t*)p_this;
130     decoder_sys_t *p_sys;
131
132     if( p_dec->fmt_in.i_codec != VLC_FOURCC( 'h', '2', '6', '4') &&
133         p_dec->fmt_in.i_codec != VLC_FOURCC( 'H', '2', '6', '4') &&
134         p_dec->fmt_in.i_codec != VLC_FOURCC( 'V', 'S', 'S', 'H') &&
135         p_dec->fmt_in.i_codec != VLC_FOURCC( 'v', 's', 's', 'h') &&
136         ( p_dec->fmt_in.i_codec != VLC_FOURCC( 'a', 'v', 'c', '1') ||
137           p_dec->fmt_in.i_extra < 7 ) )
138     {
139         return VLC_EGENERIC;
140     }
141
142     /* Allocate the memory needed to store the decoder's structure */
143     if( ( p_dec->p_sys = p_sys = malloc( sizeof(decoder_sys_t) ) ) == NULL )
144     {
145         msg_Err( p_dec, "out of memory" );
146         return VLC_EGENERIC;
147     }
148     p_sys->i_state = STATE_NOSYNC;
149     p_sys->i_offset = 0;
150     p_sys->startcode[0] = 0;
151     p_sys->startcode[1] = 0;
152     p_sys->startcode[2] = 0;
153     p_sys->startcode[3] = 1;
154     p_sys->bytestream = block_BytestreamInit( p_dec );
155     p_sys->b_slice = VLC_FALSE;
156     p_sys->p_frame = NULL;
157     p_sys->b_sps   = VLC_FALSE;
158     p_sys->b_pps   = VLC_FALSE;
159     p_sys->p_sps   = 0;
160     p_sys->p_pps   = 0;
161
162     p_sys->i_nal_type = -1;
163     p_sys->i_nal_ref_idc = -1;
164     p_sys->i_idr_pic_id = -1;
165     p_sys->i_frame_num = -1;
166
167     /* Setup properties */
168     es_format_Copy( &p_dec->fmt_out, &p_dec->fmt_in );
169     p_dec->fmt_out.i_codec = VLC_FOURCC( 'h', '2', '6', '4' );
170
171     if( p_dec->fmt_in.i_codec == VLC_FOURCC( 'a', 'v', 'c', '1' ) )
172     {
173         /* This type of stream is produced by mp4 and matroska
174          * when we want to store it in another streamformat, you need to convert
175          * The fmt_in.p_extra should ALWAYS contain the avcC
176          * The fmt_out.p_extra should contain all the SPS and PPS with 4 byte startcodes */
177         uint8_t *p = &((uint8_t*)p_dec->fmt_in.p_extra)[4];
178         int i_sps, i_pps;
179         int i;
180
181         /* Parse avcC */
182         p_sys->i_avcC_length_size = 1 + ((*p++)&0x03);
183
184         /* Read SPS */
185         i_sps = (*p++)&0x1f;
186         for( i = 0; i < i_sps; i++ )
187         {
188             int i_length = GetWBE( p );
189             block_t *p_sps = nal_get_annexeb( p_dec, p + 2, i_length );
190
191             p_sys->p_sps = block_Duplicate( p_sps );
192             p_sps->i_pts = p_sps->i_dts = mdate();
193             ParseNALBlock( p_dec, p_sps );
194             p += 2 + i_length;
195         }
196         /* Read PPS */
197         i_pps = *p++;
198         for( i = 0; i < i_pps; i++ )
199         {
200             int i_length = GetWBE( p );
201             block_t *p_pps = nal_get_annexeb( p_dec, p + 2, i_length );
202
203             p_sys->p_pps = block_Duplicate( p_pps );
204             p_pps->i_pts = p_pps->i_dts = mdate();
205             ParseNALBlock( p_dec, p_pps );
206             p += 2 + i_length;
207         }
208         msg_Dbg( p_dec, "avcC length size=%d, sps=%d, pps=%d",
209                  p_sys->i_avcC_length_size, i_sps, i_pps );
210
211         /* FIXME: FFMPEG isn't happy at all if you leave this */
212         if( p_dec->fmt_out.i_extra ) free( p_dec->fmt_out.p_extra );
213         p_dec->fmt_out.i_extra = 0; p_dec->fmt_out.p_extra = NULL;
214         
215         /* Set the new extradata */
216         p_dec->fmt_out.i_extra = p_sys->p_pps->i_buffer + p_sys->p_sps->i_buffer;
217         p_dec->fmt_out.p_extra = (uint8_t*)malloc( p_dec->fmt_out.i_extra );
218         memcpy( p_dec->fmt_out.p_extra, p_sys->p_pps->p_buffer, p_sys->p_pps->i_buffer);
219         memcpy( p_dec->fmt_out.p_extra+p_sys->p_pps->i_buffer, p_sys->p_sps->p_buffer, p_sys->p_sps->i_buffer);
220
221         /* Set callback */
222         p_dec->pf_packetize = PacketizeAVC1;
223     }
224     else
225     {
226         /* This type of stream contains data with 3 of 4 byte startcodes 
227          * The fmt_in.p_extra MAY contain SPS/PPS with 4 byte startcodes
228          * The fmt_out.p_extra should be the same */
229          
230         /* Set callback */
231         p_dec->pf_packetize = Packetize;
232
233         /* */
234         if( p_dec->fmt_in.i_extra > 0 )
235         {
236             block_t *p_init = block_New( p_dec, p_dec->fmt_in.i_extra );
237             block_t *p_pic;
238
239             memcpy( p_init->p_buffer, p_dec->fmt_in.p_extra,
240                     p_dec->fmt_in.i_extra );
241
242             while( ( p_pic = Packetize( p_dec, &p_init ) ) )
243             {
244                 /* Should not occur because we should only receive SPS/PPS */
245                 block_Release( p_pic );
246             }
247         }
248     }
249
250     return VLC_SUCCESS;
251 }
252
253 /*****************************************************************************
254  * Close: clean up the packetizer
255  *****************************************************************************/
256 static void Close( vlc_object_t *p_this )
257 {
258     decoder_t *p_dec = (decoder_t*)p_this;
259     decoder_sys_t *p_sys = p_dec->p_sys;
260
261     if( p_sys->p_frame ) block_ChainRelease( p_sys->p_frame );
262     if( p_sys->p_sps ) block_Release( p_sys->p_sps );
263     if( p_sys->p_pps ) block_Release( p_sys->p_pps );
264     block_BytestreamRelease( &p_sys->bytestream );
265     free( p_sys );
266 }
267
268 /****************************************************************************
269  * Packetize: the whole thing
270  * Search for the startcodes 3 or more bytes
271  * Feed ParseNALBlock ALWAYS with 4 byte startcode prepended NALs
272  ****************************************************************************/
273 static block_t *Packetize( decoder_t *p_dec, block_t **pp_block )
274 {
275     decoder_sys_t *p_sys = p_dec->p_sys;
276     block_t       *p_pic;
277
278     if( !pp_block || !*pp_block ) return NULL;
279
280     block_BytestreamPush( &p_sys->bytestream, *pp_block );
281
282     for( ;; )
283     {
284         switch( p_sys->i_state )
285         {
286             case STATE_NOSYNC:
287                 /* Skip until 3 byte startcode 0 0 1 */
288                 if( block_FindStartcodeFromOffset( &p_sys->bytestream,
289                       &p_sys->i_offset, p_sys->startcode+1, 3 ) == VLC_SUCCESS)
290                 {
291                     p_sys->i_state = STATE_NEXT_SYNC;
292                 }
293
294                 if( p_sys->i_offset )
295                 {
296                     /* skip the data */
297                     block_SkipBytes( &p_sys->bytestream, p_sys->i_offset );
298                     p_sys->i_offset = 0;
299                     block_BytestreamFlush( &p_sys->bytestream );
300                 }
301
302                 if( p_sys->i_state != STATE_NEXT_SYNC )
303                 {
304                     /* Need more data */
305                     return NULL;
306                 }
307
308                 p_sys->i_offset = 1; /* To find next startcode */
309
310             case STATE_NEXT_SYNC:
311                 /* Find the next 3 byte startcode 0 0 1*/
312                 if( block_FindStartcodeFromOffset( &p_sys->bytestream,
313                       &p_sys->i_offset, p_sys->startcode+1, 3 ) != VLC_SUCCESS)
314                 {
315                     /* Need more data */
316                     return NULL;
317                 }
318
319                 /* Get the new fragment and set the pts/dts */
320                 p_pic = block_New( p_dec, p_sys->i_offset +1 );
321                 p_pic->i_pts = p_sys->bytestream.p_block->i_pts;
322                 p_pic->i_dts = p_sys->bytestream.p_block->i_dts;
323                 /* Force 4 byte startcode 0 0 0 1 */
324                 p_pic->p_buffer[0] = 0;
325
326                 block_GetBytes( &p_sys->bytestream, &p_pic->p_buffer[1],
327                                 p_pic->i_buffer-1 );
328
329                 /* Remove trailing 0 bytes */
330                 while( p_pic->i_buffer && (!p_pic->p_buffer[p_pic->i_buffer-1] ) ) p_pic->i_buffer--;
331                 p_sys->i_offset = 0;
332
333                 /* Parse the NAL */
334                 if( !( p_pic = ParseNALBlock( p_dec, p_pic ) ) )
335                 {
336                     p_sys->i_state = STATE_NOSYNC;
337                     break;
338                 }
339 #if 0
340                 msg_Dbg( p_dec, "pts="I64Fd" dts="I64Fd,
341                          p_pic->i_pts, p_pic->i_dts );
342 #endif
343
344                 /* So p_block doesn't get re-added several times */
345                 *pp_block = block_BytestreamPop( &p_sys->bytestream );
346
347                 p_sys->i_state = STATE_NOSYNC;
348
349                 return p_pic;
350         }
351     }
352 }
353
354 /****************************************************************************
355  * PacketizeAVC1: Takes VCL blocks of data and creates annexe B type NAL stream
356  * Will always use 4 byte 0 0 0 1 startcodes
357  * Will prepend a SPS and PPS before each keyframe
358  ****************************************************************************/
359 static block_t *PacketizeAVC1( decoder_t *p_dec, block_t **pp_block )
360 {
361     decoder_sys_t *p_sys = p_dec->p_sys;
362     block_t       *p_block;
363     block_t       *p_ret = NULL;
364     uint8_t       *p;
365
366     if( !pp_block || !*pp_block ) return NULL;
367
368     p_block = *pp_block;
369     *pp_block = NULL;
370
371     for( p = p_block->p_buffer; p < &p_block->p_buffer[p_block->i_buffer]; )
372     {
373         block_t *p_pic;
374         int i_size = 0;
375         int i;
376
377         for( i = 0; i < p_sys->i_avcC_length_size; i++ )
378         {
379             i_size = (i_size << 8) | (*p++);
380         }
381
382         if( i_size > 0 )
383         {
384             block_t *p_part = nal_get_annexeb( p_dec, p, i_size );
385
386             p_part->i_dts = p_block->i_dts;
387             p_part->i_pts = p_block->i_pts;
388
389             /* Parse the NAL */
390             if( ( p_pic = ParseNALBlock( p_dec, p_part ) ) )
391             {
392                 block_ChainAppend( &p_ret, p_pic );
393             }
394         }
395         p += i_size;
396     }
397     block_Release( p_block );
398
399     return p_ret;
400 }
401
402 static block_t *nal_get_annexeb( decoder_t *p_dec, uint8_t *p, int i_size )
403 {
404     block_t *p_nal;
405
406     p_nal = block_New( p_dec, 4 + i_size );
407
408     /* Add start code */
409     p_nal->p_buffer[0] = 0x00;
410     p_nal->p_buffer[1] = 0x00;
411     p_nal->p_buffer[2] = 0x00;
412     p_nal->p_buffer[3] = 0x01;
413
414     /* Copy nalu */
415     memcpy( &p_nal->p_buffer[4], p, i_size );
416
417     return p_nal;
418 }
419
420 static void nal_get_decoded( uint8_t **pp_ret, int *pi_ret,
421                              uint8_t *src, int i_src )
422 {
423     uint8_t *end = &src[i_src];
424     uint8_t *dst = malloc( i_src );
425
426     *pp_ret = dst;
427
428     while( src < end )
429     {
430         if( src < end - 3 && src[0] == 0x00 && src[1] == 0x00 &&
431             src[2] == 0x03 )
432         {
433             *dst++ = 0x00;
434             *dst++ = 0x00;
435
436             src += 3;
437             continue;
438         }
439         *dst++ = *src++;
440     }
441
442     *pi_ret = dst - *pp_ret;
443 }
444
445 static inline int bs_read_ue( bs_t *s )
446 {
447     int i = 0;
448
449     while( bs_read1( s ) == 0 && s->p < s->p_end && i < 32 )
450     {
451         i++;
452     }
453     return( ( 1 << i) - 1 + bs_read( s, i ) );
454 }
455
456 static inline int bs_read_se( bs_t *s )
457 {
458     int val = bs_read_ue( s );
459
460     return val&0x01 ? (val+1)/2 : -(val/2);
461 }
462
463
464 /*****************************************************************************
465  * ParseNALBlock: parses annexB type NALs
466  * All p_frag blocks are required to start with 0 0 0 1 4-byte startcode 
467  *****************************************************************************/
468 static block_t *ParseNALBlock( decoder_t *p_dec, block_t *p_frag )
469 {
470     decoder_sys_t *p_sys = p_dec->p_sys;
471     block_t *p_pic = NULL;
472
473     const int i_nal_ref_idc = (p_frag->p_buffer[4] >> 5)&0x03;
474     const int i_nal_type = p_frag->p_buffer[4]&0x1f;
475
476 #define OUTPUT \
477     do {                                                      \
478         p_pic = block_ChainGather( p_sys->p_frame );          \
479         p_pic->i_length = 0;    /* FIXME */                   \
480                                                               \
481         p_sys->p_frame = NULL;                                \
482         p_sys->b_slice = VLC_FALSE;                           \
483                                                               \
484         if( ( p_pic->i_flags & BLOCK_FLAG_TYPE_I ) &&         \
485               p_sys->p_sps && p_sys->p_pps )                  \
486         {                                                     \
487             block_t *p_sps = block_Duplicate( p_sys->p_sps ); \
488             block_t *p_pps = block_Duplicate( p_sys->p_pps ); \
489             p_sps->i_dts = p_pps->i_dts = p_pic->i_dts;       \
490             p_sps->i_pts = p_pps->i_pts = p_pic->i_pts;       \
491             block_ChainAppend( &p_sps, p_pps );               \
492             block_ChainAppend( &p_sps, p_pic );               \
493             p_pic = block_ChainGather( p_sps );               \
494         }                                                     \
495     } while(0)
496
497
498     if( p_sys->b_slice && !p_sys->b_sps )
499     {
500         block_ChainRelease( p_sys->p_frame );
501         msg_Warn( p_dec, "waiting for SPS" );
502
503         /* Reset context */
504         p_sys->p_frame = NULL;
505         p_sys->b_slice = VLC_FALSE;
506     }
507
508     if( !p_sys->b_sps &&
509         i_nal_type >= NAL_SLICE && i_nal_type <= NAL_SLICE_IDR )
510     {
511         p_sys->b_slice = VLC_TRUE;
512         /* Fragment will be discarded later on */
513     }
514     else if( i_nal_type >= NAL_SLICE && i_nal_type <= NAL_SLICE_IDR )
515     {
516         uint8_t *dec;
517         int i_dec, i_first_mb, i_slice_type, i_frame_num, i_pic_flags = 0;
518         vlc_bool_t b_pic = VLC_FALSE;
519         bs_t s;
520
521         /* do not convert the whole frame */
522         nal_get_decoded( &dec, &i_dec, &p_frag->p_buffer[5],
523                          __MIN( p_frag->i_buffer - 5, 60 ) );
524         bs_init( &s, dec, i_dec );
525
526         /* first_mb_in_slice */
527         i_first_mb = bs_read_ue( &s );
528
529         /* slice_type */
530         switch( (i_slice_type = bs_read_ue( &s )) )
531         {
532             case 0: case 5:
533                 i_pic_flags = BLOCK_FLAG_TYPE_P;
534                 break;
535             case 1: case 6:
536                 i_pic_flags = BLOCK_FLAG_TYPE_B;
537                 break;
538             case 2: case 7:
539                 i_pic_flags = BLOCK_FLAG_TYPE_I;
540                 break;
541             case 3: case 8: /* SP */
542                 i_pic_flags = BLOCK_FLAG_TYPE_P;
543                 break;
544             case 4: case 9:
545                 i_pic_flags = BLOCK_FLAG_TYPE_I;
546                 break;
547         }
548         p_frag->i_flags |= i_pic_flags;
549
550         /* pic_parameter_set_id */
551         bs_read_ue( &s );
552         /* frame_num */
553         i_frame_num = bs_read( &s, p_sys->i_log2_max_frame_num + 4 );
554
555         /* Detection of the first VCL NAL unit of a primary coded picture
556          * (cf. 7.4.1.2.4) */
557         if( i_frame_num != p_sys->i_frame_num ||
558             ( (i_nal_ref_idc != p_sys->i_nal_ref_idc) &&
559               (!i_nal_ref_idc || !p_sys->i_nal_ref_idc) ) )
560         {
561             b_pic = VLC_TRUE;
562         }
563         p_sys->i_frame_num = i_frame_num;
564         p_sys->i_nal_ref_idc = i_nal_ref_idc;
565
566         if( !p_sys->b_frame_mbs_only )
567         {
568             /* field_pic_flag */
569             if( bs_read( &s, 1 ) )
570             {
571                 /* bottom_field_flag */
572                 bs_read( &s, 1 );
573             }
574         }
575
576         if( i_nal_type == NAL_SLICE_IDR )
577         {
578             /* id_pic_id */
579             int i_idr_pic_id = bs_read_ue( &s );
580             if( p_sys->i_nal_type != i_nal_type ) b_pic = VLC_TRUE;
581             if( p_sys->i_idr_pic_id != i_idr_pic_id ) b_pic = VLC_TRUE;
582             p_sys->i_idr_pic_id = i_idr_pic_id;
583         }
584         p_sys->i_nal_type = i_nal_type;
585
586         if( b_pic && p_sys->b_slice ) OUTPUT;
587
588         p_sys->b_slice = VLC_TRUE;
589
590         free( dec );
591     }
592     else if( i_nal_type == NAL_SPS )
593     {
594         uint8_t *dec;
595         int     i_dec;
596         bs_t s;
597         int i_tmp;
598
599         if( !p_sys->b_sps ) msg_Dbg( p_dec, "found NAL_SPS" );
600
601         p_sys->b_sps = VLC_TRUE;
602
603         nal_get_decoded( &dec, &i_dec, &p_frag->p_buffer[5],
604                          p_frag->i_buffer - 5 );
605
606         bs_init( &s, dec, i_dec );
607         /* Skip profile(8), constraint_set012, reserver(5), level(8) */
608         bs_skip( &s, 8 + 1+1+1 + 5 + 8 );
609         /* sps id */
610         bs_read_ue( &s );
611         /* Skip i_log2_max_frame_num */
612         p_sys->i_log2_max_frame_num = bs_read_ue( &s );
613         /* Read poc_type */
614         i_tmp = bs_read_ue( &s );
615         if( i_tmp == 0 )
616         {
617             /* skip i_log2_max_poc_lsb */
618             bs_read_ue( &s );
619         }
620         else if( i_tmp == 1 )
621         {
622             int i_cycle;
623             /* skip b_delta_pic_order_always_zero */
624             bs_skip( &s, 1 );
625             /* skip i_offset_for_non_ref_pic */
626             bs_read_se( &s );
627             /* skip i_offset_for_top_to_bottom_field */
628             bs_read_se( &s );
629             /* read i_num_ref_frames_in_poc_cycle */
630             i_cycle = bs_read_ue( &s );
631             if( i_cycle > 256 ) i_cycle = 256;
632             while( i_cycle > 0 )
633             {
634                 /* skip i_offset_for_ref_frame */
635                 bs_read_se(&s );
636             }
637         }
638         /* i_num_ref_frames */
639         bs_read_ue( &s );
640         /* b_gaps_in_frame_num_value_allowed */
641         bs_skip( &s, 1 );
642
643         /* Read size */
644         p_dec->fmt_out.video.i_width  = 16 * ( bs_read_ue( &s ) + 1 );
645         p_dec->fmt_out.video.i_height = 16 * ( bs_read_ue( &s ) + 1 );
646
647         /* b_frame_mbs_only */
648         p_sys->b_frame_mbs_only = bs_read( &s, 1 );
649         if( p_sys->b_frame_mbs_only == 0 )
650         {
651             bs_skip( &s, 1 );
652         }
653         /* b_direct8x8_inference */
654         bs_skip( &s, 1 );
655
656         /* crop */
657         i_tmp = bs_read( &s, 1 );
658         if( i_tmp )
659         {
660             /* left */
661             bs_read_ue( &s );
662             /* right */
663             bs_read_ue( &s );
664             /* top */
665             bs_read_ue( &s );
666             /* bottom */
667             bs_read_ue( &s );
668         }
669
670         /* vui */
671         i_tmp = bs_read( &s, 1 );
672         if( i_tmp )
673         {
674             /* read the aspect ratio part if any FIXME check it */
675             i_tmp = bs_read( &s, 1 );
676             if( i_tmp )
677             {
678                 static const struct { int w, h; } sar[14] =
679                 {
680                     { 0,   0 }, { 1,   1 }, { 12, 11 }, { 10, 11 },
681                     { 16, 11 }, { 40, 33 }, { 24, 11 }, { 20, 11 },
682                     { 32, 11 }, { 80, 33 }, { 18, 11 }, { 15, 11 },
683                     { 64, 33 }, { 160,99 },
684                 };
685                 int i_sar = bs_read( &s, 8 );
686                 int w, h;
687
688                 if( i_sar < 14 )
689                 {
690                     w = sar[i_sar].w;
691                     h = sar[i_sar].h;
692                 }
693                 else
694                 {
695                     w = bs_read( &s, 16 );
696                     h = bs_read( &s, 16 );
697                 }
698                 if( h != 0 )
699                     p_dec->fmt_out.video.i_aspect = VOUT_ASPECT_FACTOR * w /
700                         h * p_dec->fmt_out.video.i_width /
701                         p_dec->fmt_out.video.i_height;
702                 else
703                     p_dec->fmt_out.video.i_aspect = VOUT_ASPECT_FACTOR;
704             }
705         }
706
707         free( dec );
708
709         if( p_sys->b_slice ) OUTPUT;
710
711         /* We have a new SPS */
712         if( p_sys->p_sps ) block_Release( p_sys->p_sps );
713         p_sys->p_sps = p_frag;
714
715         /* Do not append the SPS because we will insert it on keyframes */
716         return p_pic;
717     }
718     else if( i_nal_type == NAL_PPS )
719     {
720         bs_t s;
721         bs_init( &s, &p_frag->p_buffer[5], p_frag->i_buffer - 5 );
722
723         if( !p_sys->b_pps ) msg_Dbg( p_dec, "found NAL_PPS" );
724         p_sys->b_pps = VLC_TRUE;
725
726         /* TODO */
727
728         if( p_sys->b_slice ) OUTPUT;
729
730         /* We have a new PPS */
731         if( p_sys->p_pps ) block_Release( p_sys->p_pps );
732         p_sys->p_pps = p_frag;
733
734         /* Do not append the PPS because we will insert it on keyframes */
735         return p_pic;
736     }
737     else if( i_nal_type == NAL_AU_DELIMITER ||
738              i_nal_type == NAL_SEI ||
739              ( i_nal_type >= 13 && i_nal_type <= 18 ) )
740     {
741         if( p_sys->b_slice ) OUTPUT;
742     }
743
744 #undef OUTPUT
745
746     /* Append the block */
747     block_ChainAppend( &p_sys->p_frame, p_frag );
748
749     return p_pic;
750 }