Fix regression introduced in [24381]
[vlc.git] / 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  *          Derk-Jan Hartman <hartman at videolan dot org>
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License as published by
14  * the Free Software Foundation; either version 2 of the License, or
15  * (at your option) any later version.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  * GNU General Public License for more details.
21  *
22  * You should have received a copy of the GNU General Public License
23  * along with this program; if not, write to the Free Software
24  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
25  *****************************************************************************/
26
27 /*****************************************************************************
28  * Preamble
29  *****************************************************************************/
30
31 #include <vlc/vlc.h>
32 #include <vlc_sout.h>
33 #include <vlc_codec.h>
34 #include <vlc_block.h>
35
36 #include "vlc_block_helper.h"
37 #include "vlc_bits.h"
38
39 /*****************************************************************************
40  * Module descriptor
41  *****************************************************************************/
42 static int  Open ( vlc_object_t * );
43 static void Close( vlc_object_t * );
44
45 vlc_module_begin();
46     set_category( CAT_SOUT );
47     set_subcategory( SUBCAT_SOUT_PACKETIZER );
48     set_description( _("H.264 video packetizer") );
49     set_capability( "packetizer", 50 );
50     set_callbacks( Open, Close );
51 vlc_module_end();
52
53
54 /****************************************************************************
55  * Local prototypes
56  ****************************************************************************/
57 static block_t *Packetize( decoder_t *, block_t ** );
58 static block_t *PacketizeAVC1( decoder_t *, block_t ** );
59
60 typedef struct
61 {
62     int i_nal_type;
63     int i_nal_ref_idc;
64
65     int i_frame_type;
66     int i_pic_parameter_set_id;
67     int i_frame_num;
68
69     int i_field_pic_flag;
70     int i_bottom_field_flag;
71
72     int i_idr_pic_id;
73
74     int i_pic_order_cnt_lsb;
75     int i_delta_pic_order_cnt_bottom;
76
77     int i_delta_pic_order_cnt0;
78     int i_delta_pic_order_cnt1;
79 } slice_t;
80
81 struct decoder_sys_t
82 {
83     block_bytestream_t bytestream;
84
85     int     i_state;
86     int     i_offset;
87     uint8_t startcode[4];
88
89     vlc_bool_t b_slice;
90     block_t    *p_frame;
91
92     vlc_bool_t   b_sps;
93     vlc_bool_t   b_pps;
94     vlc_bool_t   b_header;
95
96     /* avcC data */
97     int i_avcC_length_size;
98     block_t *p_sps;
99     block_t *p_pps;
100
101     /* Useful values of the Sequence Parameter Set */
102     int i_log2_max_frame_num;
103     int b_frame_mbs_only;
104     int i_pic_order_cnt_type;
105     int i_delta_pic_order_always_zero_flag;
106     int i_log2_max_pic_order_cnt_lsb;
107
108     /* Value from Picture Parameter Set */
109     int i_pic_order_present_flag;
110
111     /* Useful values of the Slice Header */
112     slice_t slice;
113 };
114
115 enum
116 {
117     STATE_NOSYNC,
118     STATE_NEXT_SYNC,
119 };
120
121 enum nal_unit_type_e
122 {
123     NAL_UNKNOWN = 0,
124     NAL_SLICE   = 1,
125     NAL_SLICE_DPA   = 2,
126     NAL_SLICE_DPB   = 3,
127     NAL_SLICE_DPC   = 4,
128     NAL_SLICE_IDR   = 5,    /* ref_idc != 0 */
129     NAL_SEI         = 6,    /* ref_idc == 0 */
130     NAL_SPS         = 7,
131     NAL_PPS         = 8,
132     NAL_AU_DELIMITER= 9
133     /* ref_idc == 0 for 6,9,10,11,12 */
134 };
135
136 enum nal_priority_e
137 {
138     NAL_PRIORITY_DISPOSABLE = 0,
139     NAL_PRIORITY_LOW        = 1,
140     NAL_PRIORITY_HIGH       = 2,
141     NAL_PRIORITY_HIGHEST    = 3,
142 };
143
144 static block_t *ParseNALBlock( decoder_t *, block_t * );
145
146 static block_t *nal_get_annexeb( decoder_t *, uint8_t *p, int );
147
148 /*****************************************************************************
149  * Open: probe the packetizer and return score
150  * When opening after demux, the packetizer is only loaded AFTER the decoder
151  * That means that what you set in fmt_out is ignored by the decoder in this special case
152  *****************************************************************************/
153 static int Open( vlc_object_t *p_this )
154 {
155     decoder_t     *p_dec = (decoder_t*)p_this;
156     decoder_sys_t *p_sys;
157
158     if( p_dec->fmt_in.i_codec != VLC_FOURCC( 'h', '2', '6', '4') &&
159         p_dec->fmt_in.i_codec != VLC_FOURCC( 'H', '2', '6', '4') &&
160         p_dec->fmt_in.i_codec != VLC_FOURCC( 'V', 'S', 'S', 'H') &&
161         p_dec->fmt_in.i_codec != VLC_FOURCC( 'v', 's', 's', 'h') &&
162         p_dec->fmt_in.i_codec != VLC_FOURCC( 'D', 'A', 'V', 'C') &&
163         ( p_dec->fmt_in.i_codec != VLC_FOURCC( 'a', 'v', 'c', '1') ||
164           p_dec->fmt_in.i_extra < 7 ) )
165     {
166         return VLC_EGENERIC;
167     }
168
169     /* Allocate the memory needed to store the decoder's structure */
170     if( ( p_dec->p_sys = p_sys = malloc( sizeof(decoder_sys_t) ) ) == NULL )
171     {
172         msg_Err( p_dec, "out of memory" );
173         return VLC_EGENERIC;
174     }
175     p_sys->i_state = STATE_NOSYNC;
176     p_sys->i_offset = 0;
177     p_sys->startcode[0] = 0;
178     p_sys->startcode[1] = 0;
179     p_sys->startcode[2] = 0;
180     p_sys->startcode[3] = 1;
181     p_sys->bytestream = block_BytestreamInit( p_dec );
182     p_sys->b_slice = VLC_FALSE;
183     p_sys->p_frame = NULL;
184     p_sys->b_sps   = VLC_FALSE;
185     p_sys->b_pps   = VLC_FALSE;
186     p_sys->p_sps   = 0;
187     p_sys->p_pps   = 0;
188     p_sys->b_header= VLC_FALSE;
189
190     p_sys->slice.i_nal_type = -1;
191     p_sys->slice.i_nal_ref_idc = -1;
192     p_sys->slice.i_idr_pic_id = -1;
193     p_sys->slice.i_frame_num = -1;
194     p_sys->slice.i_frame_type = 0;
195     p_sys->slice.i_pic_parameter_set_id = -1;
196     p_sys->slice.i_field_pic_flag = 0;
197     p_sys->slice.i_bottom_field_flag = -1;
198     p_sys->slice.i_pic_order_cnt_lsb = -1;
199     p_sys->slice.i_delta_pic_order_cnt_bottom = -1;
200
201     /* Setup properties */
202     es_format_Copy( &p_dec->fmt_out, &p_dec->fmt_in );
203     p_dec->fmt_out.i_codec = VLC_FOURCC( 'h', '2', '6', '4' );
204
205     if( p_dec->fmt_in.i_codec == VLC_FOURCC( 'a', 'v', 'c', '1' ) )
206     {
207         /* This type of stream is produced by mp4 and matroska
208          * when we want to store it in another streamformat, you need to convert
209          * The fmt_in.p_extra should ALWAYS contain the avcC
210          * The fmt_out.p_extra should contain all the SPS and PPS with 4 byte startcodes */
211         uint8_t *p = &((uint8_t*)p_dec->fmt_in.p_extra)[4];
212         int i_sps, i_pps;
213         int i;
214
215         /* Parse avcC */
216         p_sys->i_avcC_length_size = 1 + ((*p++)&0x03);
217
218         /* Read SPS */
219         i_sps = (*p++)&0x1f;
220         for( i = 0; i < i_sps; i++ )
221         {
222             int i_length = GetWBE( p );
223             block_t *p_sps = nal_get_annexeb( p_dec, p + 2, i_length );
224
225             p_sys->p_sps = block_Duplicate( p_sps );
226             p_sps->i_pts = p_sps->i_dts = mdate();
227             ParseNALBlock( p_dec, p_sps );
228             p += 2 + i_length;
229         }
230         /* Read PPS */
231         i_pps = *p++;
232         for( i = 0; i < i_pps; i++ )
233         {
234             int i_length = GetWBE( p );
235             block_t *p_pps = nal_get_annexeb( p_dec, p + 2, i_length );
236
237             p_sys->p_pps = block_Duplicate( p_pps );
238             p_pps->i_pts = p_pps->i_dts = mdate();
239             ParseNALBlock( p_dec, p_pps );
240             p += 2 + i_length;
241         }
242         msg_Dbg( p_dec, "avcC length size=%d, sps=%d, pps=%d",
243                  p_sys->i_avcC_length_size, i_sps, i_pps );
244
245         /* FIXME: FFMPEG isn't happy at all if you leave this */
246         if( p_dec->fmt_out.i_extra ) free( p_dec->fmt_out.p_extra );
247         p_dec->fmt_out.i_extra = 0; p_dec->fmt_out.p_extra = NULL;
248
249         /* Set the new extradata */
250         p_dec->fmt_out.i_extra = p_sys->p_pps->i_buffer + p_sys->p_sps->i_buffer;
251         p_dec->fmt_out.p_extra = (uint8_t*)malloc( p_dec->fmt_out.i_extra );
252         if( p_dec->fmt_out.p_extra )
253         {
254             memcpy( (uint8_t*)p_dec->fmt_out.p_extra, p_sys->p_sps->p_buffer, p_sys->p_sps->i_buffer);
255             memcpy( (uint8_t*)p_dec->fmt_out.p_extra+p_sys->p_sps->i_buffer, p_sys->p_pps->p_buffer, p_sys->p_pps->i_buffer);
256             p_sys->b_header = VLC_TRUE;
257         }
258         else p_dec->fmt_out.i_extra = 0;
259
260         /* Set callback */
261         p_dec->pf_packetize = PacketizeAVC1;
262     }
263     else
264     {
265         /* This type of stream contains data with 3 of 4 byte startcodes
266          * The fmt_in.p_extra MAY contain SPS/PPS with 4 byte startcodes
267          * The fmt_out.p_extra should be the same */
268  
269         /* Set callback */
270         p_dec->pf_packetize = Packetize;
271
272         /* */
273         if( p_dec->fmt_in.i_extra > 0 )
274         {
275             block_t *p_init = block_New( p_dec, p_dec->fmt_in.i_extra );
276             block_t *p_pic;
277
278             memcpy( p_init->p_buffer, p_dec->fmt_in.p_extra,
279                     p_dec->fmt_in.i_extra );
280
281             while( ( p_pic = Packetize( p_dec, &p_init ) ) )
282             {
283                 /* Should not occur because we should only receive SPS/PPS */
284                 block_Release( p_pic );
285             }
286         }
287     }
288
289     return VLC_SUCCESS;
290 }
291
292 /*****************************************************************************
293  * Close: clean up the packetizer
294  *****************************************************************************/
295 static void Close( vlc_object_t *p_this )
296 {
297     decoder_t *p_dec = (decoder_t*)p_this;
298     decoder_sys_t *p_sys = p_dec->p_sys;
299
300     if( p_sys->p_frame ) block_ChainRelease( p_sys->p_frame );
301     if( p_sys->p_sps ) block_Release( p_sys->p_sps );
302     if( p_sys->p_pps ) block_Release( p_sys->p_pps );
303     block_BytestreamRelease( &p_sys->bytestream );
304     free( p_sys );
305 }
306
307 /****************************************************************************
308  * Packetize: the whole thing
309  * Search for the startcodes 3 or more bytes
310  * Feed ParseNALBlock ALWAYS with 4 byte startcode prepended NALs
311  ****************************************************************************/
312 static block_t *Packetize( decoder_t *p_dec, block_t **pp_block )
313 {
314     decoder_sys_t *p_sys = p_dec->p_sys;
315     block_t       *p_pic;
316
317     if( !pp_block || !*pp_block )
318         return NULL;
319
320     if( (*pp_block)->i_flags&(BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED) )
321     {
322         if( (*pp_block)->i_flags&BLOCK_FLAG_CORRUPTED )
323         {
324             p_sys->i_state = STATE_NOSYNC;
325             block_BytestreamFlush( &p_sys->bytestream );
326
327             if( p_sys->p_frame )
328                 block_ChainRelease( p_sys->p_frame );
329             p_sys->p_frame = NULL;
330             p_sys->slice.i_frame_type = 0;
331             p_sys->b_slice = VLC_FALSE;
332         }
333         block_Release( *pp_block );
334         return NULL;
335     }
336
337     block_BytestreamPush( &p_sys->bytestream, *pp_block );
338
339     for( ;; )
340     {
341         switch( p_sys->i_state )
342         {
343             case STATE_NOSYNC:
344                 /* Skip until 3 byte startcode 0 0 1 */
345                 if( block_FindStartcodeFromOffset( &p_sys->bytestream,
346                       &p_sys->i_offset, p_sys->startcode+1, 3 ) == VLC_SUCCESS)
347                 {
348                     p_sys->i_state = STATE_NEXT_SYNC;
349                 }
350
351                 if( p_sys->i_offset )
352                 {
353                     /* skip the data */
354                     block_SkipBytes( &p_sys->bytestream, p_sys->i_offset );
355                     p_sys->i_offset = 0;
356                     block_BytestreamFlush( &p_sys->bytestream );
357                 }
358
359                 if( p_sys->i_state != STATE_NEXT_SYNC )
360                 {
361                     /* Need more data */
362                     return NULL;
363                 }
364
365                 p_sys->i_offset = 1; /* To find next startcode */
366
367             case STATE_NEXT_SYNC:
368                 /* Find the next 3 byte startcode 0 0 1*/
369                 if( block_FindStartcodeFromOffset( &p_sys->bytestream,
370                       &p_sys->i_offset, p_sys->startcode+1, 3 ) != VLC_SUCCESS)
371                 {
372                     /* Need more data */
373                     return NULL;
374                 }
375
376                 /* Get the new fragment and set the pts/dts */
377                 p_pic = block_New( p_dec, p_sys->i_offset +1 );
378                 p_pic->i_pts = p_sys->bytestream.p_block->i_pts;
379                 p_pic->i_dts = p_sys->bytestream.p_block->i_dts;
380                 /* Force 4 byte startcode 0 0 0 1 */
381                 p_pic->p_buffer[0] = 0;
382
383                 block_GetBytes( &p_sys->bytestream, &p_pic->p_buffer[1],
384                                 p_pic->i_buffer-1 );
385
386                 /* Remove trailing 0 bytes */
387                 while( p_pic->i_buffer && (!p_pic->p_buffer[p_pic->i_buffer-1] ) )
388                     p_pic->i_buffer--;
389                 p_sys->i_offset = 0;
390
391                 /* Parse the NAL */
392                 if( !( p_pic = ParseNALBlock( p_dec, p_pic ) ) )
393                 {
394                     p_sys->i_state = STATE_NOSYNC;
395                     break;
396                 }
397 #if 0
398                 msg_Dbg( p_dec, "pts="I64Fd" dts="I64Fd,
399                          p_pic->i_pts, p_pic->i_dts );
400 #endif
401
402                 /* So p_block doesn't get re-added several times */
403                 *pp_block = block_BytestreamPop( &p_sys->bytestream );
404
405                 p_sys->i_state = STATE_NOSYNC;
406
407                 return p_pic;
408         }
409     }
410 }
411
412 /****************************************************************************
413  * PacketizeAVC1: Takes VCL blocks of data and creates annexe B type NAL stream
414  * Will always use 4 byte 0 0 0 1 startcodes
415  * Will prepend a SPS and PPS before each keyframe
416  ****************************************************************************/
417 static block_t *PacketizeAVC1( decoder_t *p_dec, block_t **pp_block )
418 {
419     decoder_sys_t *p_sys = p_dec->p_sys;
420     block_t       *p_block;
421     block_t       *p_ret = NULL;
422     uint8_t       *p;
423
424     if( !pp_block || !*pp_block )
425         return NULL;
426     if( (*pp_block)->i_flags&(BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED) )
427     {
428         block_Release( *pp_block );
429         return NULL;
430     }
431
432     p_block = *pp_block;
433     *pp_block = NULL;
434
435     for( p = p_block->p_buffer; p < &p_block->p_buffer[p_block->i_buffer]; )
436     {
437         block_t *p_pic;
438         int i_size = 0;
439         int i;
440
441         for( i = 0; i < p_sys->i_avcC_length_size; i++ )
442         {
443             i_size = (i_size << 8) | (*p++);
444         }
445
446         if( i_size > 0 )
447         {
448             block_t *p_part = nal_get_annexeb( p_dec, p, i_size );
449
450             p_part->i_dts = p_block->i_dts;
451             p_part->i_pts = p_block->i_pts;
452
453             /* Parse the NAL */
454             if( ( p_pic = ParseNALBlock( p_dec, p_part ) ) )
455             {
456                 block_ChainAppend( &p_ret, p_pic );
457             }
458         }
459         p += i_size;
460     }
461     block_Release( p_block );
462
463     return p_ret;
464 }
465
466 static block_t *nal_get_annexeb( decoder_t *p_dec, uint8_t *p, int i_size )
467 {
468     block_t *p_nal;
469
470     p_nal = block_New( p_dec, 4 + i_size );
471
472     /* Add start code */
473     p_nal->p_buffer[0] = 0x00;
474     p_nal->p_buffer[1] = 0x00;
475     p_nal->p_buffer[2] = 0x00;
476     p_nal->p_buffer[3] = 0x01;
477
478     /* Copy nalu */
479     memcpy( &p_nal->p_buffer[4], p, i_size );
480
481     return p_nal;
482 }
483
484 static void nal_get_decoded( uint8_t **pp_ret, int *pi_ret,
485                              uint8_t *src, int i_src )
486 {
487     uint8_t *end = &src[i_src];
488     uint8_t *dst = malloc( i_src );
489
490     *pp_ret = dst;
491
492     if( dst )
493     {
494         while( src < end )
495         {
496             if( src < end - 3 && src[0] == 0x00 && src[1] == 0x00 &&
497                 src[2] == 0x03 )
498             {
499                 *dst++ = 0x00;
500                 *dst++ = 0x00;
501
502                 src += 3;
503                 continue;
504             }
505             *dst++ = *src++;
506         }
507     }
508     *pi_ret = dst - *pp_ret;
509 }
510
511 static inline int bs_read_ue( bs_t *s )
512 {
513     int i = 0;
514
515     while( bs_read1( s ) == 0 && s->p < s->p_end && i < 32 )
516     {
517         i++;
518     }
519     return( ( 1 << i) - 1 + bs_read( s, i ) );
520 }
521
522 static inline int bs_read_se( bs_t *s )
523 {
524     int val = bs_read_ue( s );
525
526     return val&0x01 ? (val+1)/2 : -(val/2);
527 }
528
529 /*****************************************************************************
530  * ParseNALBlock: parses annexB type NALs
531  * All p_frag blocks are required to start with 0 0 0 1 4-byte startcode
532  *****************************************************************************/
533 static block_t *ParseNALBlock( decoder_t *p_dec, block_t *p_frag )
534 {
535     decoder_sys_t *p_sys = p_dec->p_sys;
536     block_t *p_pic = NULL;
537
538     const int i_nal_ref_idc = (p_frag->p_buffer[4] >> 5)&0x03;
539     const int i_nal_type = p_frag->p_buffer[4]&0x1f;
540
541 #define OUTPUT \
542     do {                                                      \
543         if( !p_sys->b_header && p_sys->slice.i_frame_type != BLOCK_FLAG_TYPE_I) \
544             break;                                            \
545                                                               \
546         if( p_sys->slice.i_frame_type == BLOCK_FLAG_TYPE_I && p_sys->p_sps && p_sys->p_pps ) \
547         { \
548             block_t *p_sps = block_Duplicate( p_sys->p_sps ); \
549             block_t *p_pps = block_Duplicate( p_sys->p_pps ); \
550             p_sps->i_dts = p_sys->p_frame->i_dts;           \
551             p_sps->i_pts = p_sys->p_frame->i_pts;           \
552             block_ChainAppend( &p_sps, p_pps );               \
553             block_ChainAppend( &p_sps, p_sys->p_frame );      \
554             p_sys->b_header = VLC_TRUE;                       \
555             p_pic = block_ChainGather( p_sps );               \
556         } else { \
557             p_pic = block_ChainGather( p_sys->p_frame ); \
558         } \
559         p_pic->i_length = 0;    /* FIXME */                   \
560         p_pic->i_flags |= p_sys->slice.i_frame_type;          \
561             \
562         p_sys->slice.i_frame_type = 0;                        \
563         p_sys->p_frame = NULL;                                \
564         p_sys->b_slice = VLC_FALSE;                           \
565     } while(0)
566
567     if( p_sys->b_slice && ( !p_sys->b_sps || !p_sys->b_pps ) )
568     {
569         block_ChainRelease( p_sys->p_frame );
570         msg_Warn( p_dec, "waiting for SPS/PPS" );
571
572         /* Reset context */
573         p_sys->slice.i_frame_type = 0;
574         p_sys->p_frame = NULL;
575         p_sys->b_slice = VLC_FALSE;
576     }
577
578     if( ( !p_sys->b_sps || !p_sys->b_pps ) &&
579         i_nal_type >= NAL_SLICE && i_nal_type <= NAL_SLICE_IDR )
580     {
581         p_sys->b_slice = VLC_TRUE;
582         /* Fragment will be discarded later on */
583     }
584     else if( i_nal_type >= NAL_SLICE && i_nal_type <= NAL_SLICE_IDR )
585     {
586         uint8_t *dec = NULL;
587         int i_dec = 0, i_first_mb, i_slice_type;
588         slice_t slice;
589         vlc_bool_t b_pic;
590         bs_t s;
591
592         /* do not convert the whole frame */
593         nal_get_decoded( &dec, &i_dec, &p_frag->p_buffer[5],
594                          __MIN( p_frag->i_buffer - 5, 60 ) );
595         bs_init( &s, dec, i_dec );
596
597         /* first_mb_in_slice */
598         i_first_mb = bs_read_ue( &s );
599
600         /* slice_type */
601         switch( (i_slice_type = bs_read_ue( &s )) )
602         {
603         case 0: case 5:
604             slice.i_frame_type = BLOCK_FLAG_TYPE_P;
605             break;
606         case 1: case 6:
607             slice.i_frame_type = BLOCK_FLAG_TYPE_B;
608             break;
609         case 2: case 7:
610             slice.i_frame_type = BLOCK_FLAG_TYPE_I;
611             break;
612         case 3: case 8: /* SP */
613             slice.i_frame_type = BLOCK_FLAG_TYPE_P;
614             break;
615         case 4: case 9:
616             slice.i_frame_type = BLOCK_FLAG_TYPE_I;
617             break;
618         default:
619             slice.i_frame_type = 0;
620             break;
621         }
622
623         /* */
624         slice.i_nal_type = i_nal_type;
625         slice.i_nal_ref_idc = i_nal_ref_idc;
626
627         slice.i_pic_parameter_set_id = bs_read_ue( &s );
628         slice.i_frame_num = bs_read( &s, p_sys->i_log2_max_frame_num + 4 );
629
630         slice.i_field_pic_flag = 0;
631         slice.i_bottom_field_flag = -1;
632         if( !p_sys->b_frame_mbs_only )
633         {
634             /* field_pic_flag */
635             slice.i_field_pic_flag = bs_read( &s, 1 );
636             if( slice.i_field_pic_flag )
637                 slice.i_bottom_field_flag = bs_read( &s, 1 );
638         }
639
640         slice.i_idr_pic_id = p_sys->slice.i_idr_pic_id;
641         if( slice.i_nal_type == NAL_SLICE_IDR )
642             slice.i_idr_pic_id = bs_read_ue( &s );
643
644         slice.i_pic_order_cnt_lsb = -1;
645         slice.i_delta_pic_order_cnt_bottom = -1;
646         slice.i_delta_pic_order_cnt0 = 0;
647         slice.i_delta_pic_order_cnt1 = 0;
648         if( p_sys->i_pic_order_cnt_type == 0 )
649         {
650             slice.i_pic_order_cnt_lsb = bs_read( &s, p_sys->i_log2_max_pic_order_cnt_lsb + 4 );
651             if( p_sys->i_pic_order_present_flag && !slice.i_field_pic_flag )
652                 slice.i_delta_pic_order_cnt_bottom = bs_read_se( &s );
653         }
654         else if( (p_sys->i_pic_order_cnt_type == 1) &&
655                  (!p_sys->i_delta_pic_order_always_zero_flag) )
656         {
657             slice.i_delta_pic_order_cnt0 = bs_read_se( &s );
658             if( p_sys->i_pic_order_present_flag && !slice.i_field_pic_flag )
659                 slice.i_delta_pic_order_cnt1 = bs_read_se( &s );
660         }
661
662         /* Detection of the first VCL NAL unit of a primary coded picture
663          * (cf. 7.4.1.2.4) */
664         b_pic = VLC_FALSE;
665         if( slice.i_frame_num != p_sys->slice.i_frame_num ||
666             slice.i_pic_parameter_set_id != p_sys->slice.i_pic_parameter_set_id ||
667             slice.i_field_pic_flag != p_sys->slice.i_field_pic_flag ||
668             slice.i_nal_ref_idc != p_sys->slice.i_nal_ref_idc )
669             b_pic = VLC_TRUE;
670         if( (slice.i_bottom_field_flag != -1) &&
671             (p_sys->slice.i_bottom_field_flag != -1) &&
672             (slice.i_bottom_field_flag != p_sys->slice.i_bottom_field_flag) )
673             b_pic = VLC_TRUE;
674         if( p_sys->i_pic_order_cnt_type == 0 &&
675             ( slice.i_pic_order_cnt_lsb != p_sys->slice.i_pic_order_cnt_lsb ||
676               slice.i_delta_pic_order_cnt_bottom != p_sys->slice.i_delta_pic_order_cnt_bottom ) )
677             b_pic = VLC_TRUE;
678         else if( p_sys->i_pic_order_cnt_type == 1 &&
679                  ( slice.i_delta_pic_order_cnt0 != p_sys->slice.i_delta_pic_order_cnt0 ||
680                    slice.i_delta_pic_order_cnt1 != p_sys->slice.i_delta_pic_order_cnt1 ) )
681             b_pic = VLC_TRUE;
682         if( ( slice.i_nal_type == NAL_SLICE_IDR || p_sys->slice.i_nal_type == NAL_SLICE_IDR ) &&
683             ( slice.i_nal_type != p_sys->slice.i_nal_type || slice.i_idr_pic_id != p_sys->slice.i_idr_pic_id ) )
684                 b_pic = VLC_TRUE;
685
686         /* */
687         p_sys->slice = slice;
688
689         if( b_pic && p_sys->b_slice )
690             OUTPUT;
691
692         p_sys->b_slice = VLC_TRUE;
693
694         free( dec );
695     }
696     else if( i_nal_type == NAL_SPS )
697     {
698         uint8_t *dec = NULL;
699         int     i_dec = 0;
700         bs_t s;
701         int i_tmp;
702
703         if( !p_sys->b_sps ) msg_Dbg( p_dec, "found NAL_SPS" );
704
705         p_sys->b_sps = VLC_TRUE;
706
707         nal_get_decoded( &dec, &i_dec, &p_frag->p_buffer[5],
708                          p_frag->i_buffer - 5 );
709
710         bs_init( &s, dec, i_dec );
711         /* Skip profile(8), constraint_set012, reserver(5), level(8) */
712         bs_skip( &s, 8 + 1+1+1 + 5 + 8 );
713         /* sps id */
714         bs_read_ue( &s );
715         /* Skip i_log2_max_frame_num */
716         p_sys->i_log2_max_frame_num = bs_read_ue( &s );
717         if( p_sys->i_log2_max_frame_num > 12)
718             p_sys->i_log2_max_frame_num = 12;
719         /* Read poc_type */
720         p_sys->i_pic_order_cnt_type = bs_read_ue( &s );
721         if( p_sys->i_pic_order_cnt_type == 0 )
722         {
723             /* skip i_log2_max_poc_lsb */
724             p_sys->i_log2_max_pic_order_cnt_lsb = bs_read_ue( &s );
725             if( p_sys->i_log2_max_pic_order_cnt_lsb > 12 )
726                 p_sys->i_log2_max_pic_order_cnt_lsb = 12;
727         }
728         else if( p_sys->i_pic_order_cnt_type == 1 )
729         {
730             int i_cycle;
731             /* skip b_delta_pic_order_always_zero */
732             p_sys->i_delta_pic_order_always_zero_flag = bs_read( &s, 1 );
733             /* skip i_offset_for_non_ref_pic */
734             bs_read_se( &s );
735             /* skip i_offset_for_top_to_bottom_field */
736             bs_read_se( &s );
737             /* read i_num_ref_frames_in_poc_cycle */
738             i_cycle = bs_read_ue( &s );
739             if( i_cycle > 256 ) i_cycle = 256;
740             while( i_cycle > 0 )
741             {
742                 /* skip i_offset_for_ref_frame */
743                 bs_read_se(&s );
744             }
745         }
746         /* i_num_ref_frames */
747         bs_read_ue( &s );
748         /* b_gaps_in_frame_num_value_allowed */
749         bs_skip( &s, 1 );
750
751         /* Read size */
752         p_dec->fmt_out.video.i_width  = 16 * ( bs_read_ue( &s ) + 1 );
753         p_dec->fmt_out.video.i_height = 16 * ( bs_read_ue( &s ) + 1 );
754
755         /* b_frame_mbs_only */
756         p_sys->b_frame_mbs_only = bs_read( &s, 1 );
757         if( p_sys->b_frame_mbs_only == 0 )
758         {
759             bs_skip( &s, 1 );
760         }
761         /* b_direct8x8_inference */
762         bs_skip( &s, 1 );
763
764         /* crop */
765         i_tmp = bs_read( &s, 1 );
766         if( i_tmp )
767         {
768             /* left */
769             bs_read_ue( &s );
770             /* right */
771             bs_read_ue( &s );
772             /* top */
773             bs_read_ue( &s );
774             /* bottom */
775             bs_read_ue( &s );
776         }
777
778         /* vui */
779         i_tmp = bs_read( &s, 1 );
780         if( i_tmp )
781         {
782             /* read the aspect ratio part if any FIXME check it */
783             i_tmp = bs_read( &s, 1 );
784             if( i_tmp )
785             {
786                 static const struct { int w, h; } sar[14] =
787                 {
788                     { 0,   0 }, { 1,   1 }, { 12, 11 }, { 10, 11 },
789                     { 16, 11 }, { 40, 33 }, { 24, 11 }, { 20, 11 },
790                     { 32, 11 }, { 80, 33 }, { 18, 11 }, { 15, 11 },
791                     { 64, 33 }, { 160,99 },
792                 };
793                 int i_sar = bs_read( &s, 8 );
794                 int w, h;
795
796                 if( i_sar < 14 )
797                 {
798                     w = sar[i_sar].w;
799                     h = sar[i_sar].h;
800                 }
801                 else
802                 {
803                     w = bs_read( &s, 16 );
804                     h = bs_read( &s, 16 );
805                 }
806                 if( h != 0 )
807                     p_dec->fmt_out.video.i_aspect = VOUT_ASPECT_FACTOR * w /
808                         h * p_dec->fmt_out.video.i_width /
809                         p_dec->fmt_out.video.i_height;
810                 else
811                     p_dec->fmt_out.video.i_aspect = VOUT_ASPECT_FACTOR;
812             }
813         }
814
815         free( dec );
816
817         if( p_sys->b_slice ) OUTPUT;
818
819         /* We have a new SPS */
820         if( p_sys->p_sps ) block_Release( p_sys->p_sps );
821         p_sys->p_sps = p_frag;
822
823         /* Do not append the SPS because we will insert it on keyframes */
824         return p_pic;
825     }
826     else if( i_nal_type == NAL_PPS )
827     {
828         bs_t s;
829
830         bs_init( &s, &p_frag->p_buffer[5], p_frag->i_buffer - 5 );
831         bs_read_ue( &s ); // pps id
832         bs_read_ue( &s ); // sps id
833         bs_skip( &s, 1 ); // entropy coding mode flag
834         p_sys->i_pic_order_present_flag = bs_read( &s, 1 );
835
836         if( !p_sys->b_pps ) msg_Dbg( p_dec, "found NAL_PPS" );
837         p_sys->b_pps = VLC_TRUE;
838
839         /* TODO */
840
841         if( p_sys->b_slice ) OUTPUT;
842
843         /* We have a new PPS */
844         if( p_sys->p_pps ) block_Release( p_sys->p_pps );
845         p_sys->p_pps = p_frag;
846
847         /* Do not append the PPS because we will insert it on keyframes */
848         return p_pic;
849     }
850     else if( i_nal_type == NAL_AU_DELIMITER ||
851              i_nal_type == NAL_SEI ||
852              ( i_nal_type >= 13 && i_nal_type <= 18 ) )
853     {
854         if( p_sys->b_slice ) OUTPUT;
855     }
856
857 #undef OUTPUT
858
859     /* Append the block */
860     block_ChainAppend( &p_sys->p_frame, p_frag );
861
862     return p_pic;
863 }