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