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
  31 #ifdef HAVE_CONFIG_H
  32 # include "config.h"
  33 #endif
  34
  35 #include <vlc/vlc.h>
  36 #include <vlc_sout.h>
  37 #include <vlc_codec.h>
  38 #include <vlc_block.h>
  39
  40 #include "vlc_block_helper.h"
  41 #include "vlc_bits.h"
  42
  43 /*****************************************************************************
  44  * Module descriptor
  45  *****************************************************************************/
  46 static int  Open ( vlc_object_t * );
  47 static void Close( vlc_object_t * );
  48
  49 vlc_module_begin();
  50     set_category( CAT_SOUT );
  51     set_subcategory( SUBCAT_SOUT_PACKETIZER );
  52     set_description( _("H.264 video packetizer") );
  53     set_capability( "packetizer", 50 );
  54     set_callbacks( Open, Close );
  55 vlc_module_end();
  56
  57
  58 /****************************************************************************
  59  * Local prototypes
  60  ****************************************************************************/
  61 static block_t *Packetize( decoder_t *, block_t ** );
  62 static block_t *PacketizeAVC1( decoder_t *, block_t ** );
  63
  64 typedef struct
  65 {
  66     int i_nal_type;
  67     int i_nal_ref_idc;
  68
  69     int i_frame_type;
  70     int i_pic_parameter_set_id;
  71     int i_frame_num;
  72
  73     int i_field_pic_flag;
  74     int i_bottom_field_flag;
  75
  76     int i_idr_pic_id;
  77
  78     int i_pic_order_cnt_lsb;
  79     int i_delta_pic_order_cnt_bottom;
  80
  81     int i_delta_pic_order_cnt0;
  82     int i_delta_pic_order_cnt1;
  83 } slice_t;
  84
  85 struct decoder_sys_t
  86 {
  87     block_bytestream_t bytestream;
  88
  89     int     i_state;
  90     size_t  i_offset;
  91     uint8_t startcode[4];
  92
  93     vlc_bool_t b_slice;
  94     block_t    *p_frame;
  95
  96     vlc_bool_t   b_sps;
  97     vlc_bool_t   b_pps;
  98     vlc_bool_t   b_header;
  99
 100     /* avcC data */
 101     int i_avcC_length_size;
 102     block_t *p_sps;
 103     block_t *p_pps;
 104
 105     /* Useful values of the Sequence Parameter Set */
 106     int i_log2_max_frame_num;
 107     int b_frame_mbs_only;
 108     int i_pic_order_cnt_type;
 109     int i_delta_pic_order_always_zero_flag;
 110     int i_log2_max_pic_order_cnt_lsb;
 111
 112     /* Value from Picture Parameter Set */
 113     int i_pic_order_present_flag;
 114
 115     /* Useful values of the Slice Header */
 116     slice_t slice;
 117 };
 118
 119 enum
 120 {
 121     STATE_NOSYNC,
 122     STATE_NEXT_SYNC,
 123 };
 124
 125 enum nal_unit_type_e
 126 {
 127     NAL_UNKNOWN = 0,
 128     NAL_SLICE   = 1,
 129     NAL_SLICE_DPA   = 2,
 130     NAL_SLICE_DPB   = 3,
 131     NAL_SLICE_DPC   = 4,
 132     NAL_SLICE_IDR   = 5,    /* ref_idc != 0 */
 133     NAL_SEI         = 6,    /* ref_idc == 0 */
 134     NAL_SPS         = 7,
 135     NAL_PPS         = 8,
 136     NAL_AU_DELIMITER= 9
 137     /* ref_idc == 0 for 6,9,10,11,12 */
 138 };
 139
 140 enum nal_priority_e
 141 {
 142     NAL_PRIORITY_DISPOSABLE = 0,
 143     NAL_PRIORITY_LOW        = 1,
 144     NAL_PRIORITY_HIGH       = 2,
 145     NAL_PRIORITY_HIGHEST    = 3,
 146 };
 147
 148 static block_t *ParseNALBlock( decoder_t *, block_t * );
 149
 150 static block_t *nal_get_annexeb( decoder_t *, uint8_t *p, int );
 151
 152 /*****************************************************************************
 153  * Open: probe the packetizer and return score
 154  * When opening after demux, the packetizer is only loaded AFTER the decoder
 155  * That means that what you set in fmt_out is ignored by the decoder in this special case
 156  *****************************************************************************/
 157 static int Open( vlc_object_t *p_this )
 158 {
 159     decoder_t     *p_dec = (decoder_t*)p_this;
 160     decoder_sys_t *p_sys;
 161
 162     if( p_dec->fmt_in.i_codec != VLC_FOURCC( 'h', '2', '6', '4') &&
 163         p_dec->fmt_in.i_codec != VLC_FOURCC( 'H', '2', '6', '4') &&
 164         p_dec->fmt_in.i_codec != VLC_FOURCC( 'V', 'S', 'S', 'H') &&
 165         p_dec->fmt_in.i_codec != VLC_FOURCC( 'v', 's', 's', 'h') &&
 166         p_dec->fmt_in.i_codec != VLC_FOURCC( 'D', 'A', 'V', 'C') &&
 167         ( p_dec->fmt_in.i_codec != VLC_FOURCC( 'a', 'v', 'c', '1') ||
 168           p_dec->fmt_in.i_extra < 7 ) )
 169     {
 170         return VLC_EGENERIC;
 171     }
 172
 173     /* Allocate the memory needed to store the decoder's structure */
 174     if( ( p_dec->p_sys = p_sys = malloc( sizeof(decoder_sys_t) ) ) == NULL )
 175     {
 176         msg_Err( p_dec, "out of memory" );
 177         return VLC_EGENERIC;
 178     }
 179     p_sys->i_state = STATE_NOSYNC;
 180     p_sys->i_offset = 0;
 181     p_sys->startcode[0] = 0;
 182     p_sys->startcode[1] = 0;
 183     p_sys->startcode[2] = 0;
 184     p_sys->startcode[3] = 1;
 185     p_sys->bytestream = block_BytestreamInit();
 186     p_sys->b_slice = VLC_FALSE;
 187     p_sys->p_frame = NULL;
 188     p_sys->b_sps   = VLC_FALSE;
 189     p_sys->b_pps   = VLC_FALSE;
 190     p_sys->p_sps   = 0;
 191     p_sys->p_pps   = 0;
 192     p_sys->b_header= VLC_FALSE;
 193
 194     p_sys->slice.i_nal_type = -1;
 195     p_sys->slice.i_nal_ref_idc = -1;
 196     p_sys->slice.i_idr_pic_id = -1;
 197     p_sys->slice.i_frame_num = -1;
 198     p_sys->slice.i_frame_type = 0;
 199     p_sys->slice.i_pic_parameter_set_id = -1;
 200     p_sys->slice.i_field_pic_flag = 0;
 201     p_sys->slice.i_bottom_field_flag = -1;
 202     p_sys->slice.i_pic_order_cnt_lsb = -1;
 203     p_sys->slice.i_delta_pic_order_cnt_bottom = -1;
 204
 205     /* Setup properties */
 206     es_format_Copy( &p_dec->fmt_out, &p_dec->fmt_in );
 207     p_dec->fmt_out.i_codec = VLC_FOURCC( 'h', '2', '6', '4' );
 208
 209     if( p_dec->fmt_in.i_codec == VLC_FOURCC( 'a', 'v', 'c', '1' ) )
 210     {
 211         /* This type of stream is produced by mp4 and matroska
 212          * when we want to store it in another streamformat, you need to convert
 213          * The fmt_in.p_extra should ALWAYS contain the avcC
 214          * The fmt_out.p_extra should contain all the SPS and PPS with 4 byte startcodes */
 215         uint8_t *p = &((uint8_t*)p_dec->fmt_in.p_extra)[4];
 216         int i_sps, i_pps;
 217         int i;
 218
 219         /* Parse avcC */
 220         p_sys->i_avcC_length_size = 1 + ((*p++)&0x03);
 221
 222         /* Read SPS */
 223         i_sps = (*p++)&0x1f;
 224         for( i = 0; i < i_sps; i++ )
 225         {
 226             uint16_t i_length = GetWBE( p ); p += 2;
 227             if( i_length >
 228                 (uint8_t*)p_dec->fmt_in.p_extra + p_dec->fmt_in.i_extra - p )
 229             {
 230                 return VLC_EGENERIC;
 231             }
 232             block_t *p_sps = nal_get_annexeb( p_dec, p, i_length );
 233             if( !p_sps )
 234                 return VLC_EGENERIC;
 235             p_sys->p_sps = block_Duplicate( p_sps );
 236             p_sps->i_pts = p_sps->i_dts = mdate();
 237             ParseNALBlock( p_dec, p_sps );
 238             p += i_length;
 239         }
 240         /* Read PPS */
 241         i_pps = *p++;
 242         for( i = 0; i < i_pps; i++ )
 243         {
 244             uint16_t i_length = GetWBE( p ); p += 2;
 245             if( i_length >
 246                 (uint8_t*)p_dec->fmt_in.p_extra + p_dec->fmt_in.i_extra - p )
 247             {
 248                 return VLC_EGENERIC;
 249             }
 250             block_t *p_pps = nal_get_annexeb( p_dec, p, i_length );
 251             if( !p_pps )
 252                 return VLC_EGENERIC;
 253             p_sys->p_pps = block_Duplicate( p_pps );
 254             p_pps->i_pts = p_pps->i_dts = mdate();
 255             ParseNALBlock( p_dec, p_pps );
 256             p += i_length;
 257         }
 258         msg_Dbg( p_dec, "avcC length size=%d, sps=%d, pps=%d",
 259                  p_sys->i_avcC_length_size, i_sps, i_pps );
 260
 261         /* FIXME: FFMPEG isn't happy at all if you leave this */
 262         if( p_dec->fmt_out.i_extra ) free( p_dec->fmt_out.p_extra );
 263         p_dec->fmt_out.i_extra = 0; p_dec->fmt_out.p_extra = NULL;
 264
 265         /* Set the new extradata */
 266         p_dec->fmt_out.i_extra = p_sys->p_pps->i_buffer + p_sys->p_sps->i_buffer;
 267         p_dec->fmt_out.p_extra = (uint8_t*)malloc( p_dec->fmt_out.i_extra );
 268         if( p_dec->fmt_out.p_extra )
 269         {
 270             memcpy( (uint8_t*)p_dec->fmt_out.p_extra, p_sys->p_sps->p_buffer, p_sys->p_sps->i_buffer);
 271             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);
 272             p_sys->b_header = VLC_TRUE;
 273         }
 274         else p_dec->fmt_out.i_extra = 0;
 275
 276         /* Set callback */
 277         p_dec->pf_packetize = PacketizeAVC1;
 278     }
 279     else
 280     {
 281         /* This type of stream contains data with 3 of 4 byte startcodes
 282          * The fmt_in.p_extra MAY contain SPS/PPS with 4 byte startcodes
 283          * The fmt_out.p_extra should be the same */
 284
 285         /* Set callback */
 286         p_dec->pf_packetize = Packetize;
 287
 288         /* */
 289         if( p_dec->fmt_in.i_extra > 0 )
 290         {
 291             block_t *p_init = block_New( p_dec, p_dec->fmt_in.i_extra );
 292             block_t *p_pic;
 293
 294             memcpy( p_init->p_buffer, p_dec->fmt_in.p_extra,
 295                     p_dec->fmt_in.i_extra );
 296
 297             while( ( p_pic = Packetize( p_dec, &p_init ) ) )
 298             {
 299                 /* Should not occur because we should only receive SPS/PPS */
 300                 block_Release( p_pic );
 301             }
 302         }
 303     }
 304
 305     return VLC_SUCCESS;
 306 }
 307
 308 /*****************************************************************************
 309  * Close: clean up the packetizer
 310  *****************************************************************************/
 311 static void Close( vlc_object_t *p_this )
 312 {
 313     decoder_t *p_dec = (decoder_t*)p_this;
 314     decoder_sys_t *p_sys = p_dec->p_sys;
 315
 316     if( p_sys->p_frame ) block_ChainRelease( p_sys->p_frame );
 317     if( p_sys->p_sps ) block_Release( p_sys->p_sps );
 318     if( p_sys->p_pps ) block_Release( p_sys->p_pps );
 319     block_BytestreamRelease( &p_sys->bytestream );
 320     free( p_sys );
 321 }
 322
 323 /****************************************************************************
 324  * Packetize: the whole thing
 325  * Search for the startcodes 3 or more bytes
 326  * Feed ParseNALBlock ALWAYS with 4 byte startcode prepended NALs
 327  ****************************************************************************/
 328 static block_t *Packetize( decoder_t *p_dec, block_t **pp_block )
 329 {
 330     decoder_sys_t *p_sys = p_dec->p_sys;
 331     block_t       *p_pic;
 332
 333     if( !pp_block || !*pp_block )
 334         return NULL;
 335
 336     if( (*pp_block)->i_flags&(BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED) )
 337     {
 338         if( (*pp_block)->i_flags&BLOCK_FLAG_CORRUPTED )
 339         {
 340             p_sys->i_state = STATE_NOSYNC;
 341             block_BytestreamFlush( &p_sys->bytestream );
 342
 343             if( p_sys->p_frame )
 344                 block_ChainRelease( p_sys->p_frame );
 345             p_sys->p_frame = NULL;
 346             p_sys->slice.i_frame_type = 0;
 347             p_sys->b_slice = VLC_FALSE;
 348         }
 349         block_Release( *pp_block );
 350         return NULL;
 351     }
 352
 353     block_BytestreamPush( &p_sys->bytestream, *pp_block );
 354
 355     for( ;; )
 356     {
 357         switch( p_sys->i_state )
 358         {
 359             case STATE_NOSYNC:
 360                 /* Skip until 3 byte startcode 0 0 1 */
 361                 if( block_FindStartcodeFromOffset( &p_sys->bytestream,
 362                       &p_sys->i_offset, p_sys->startcode+1, 3 ) == VLC_SUCCESS)
 363                 {
 364                     p_sys->i_state = STATE_NEXT_SYNC;
 365                 }
 366
 367                 if( p_sys->i_offset )
 368                 {
 369                     /* skip the data */
 370                     block_SkipBytes( &p_sys->bytestream, p_sys->i_offset );
 371                     p_sys->i_offset = 0;
 372                     block_BytestreamFlush( &p_sys->bytestream );
 373                 }
 374
 375                 if( p_sys->i_state != STATE_NEXT_SYNC )
 376                 {
 377                     /* Need more data */
 378                     return NULL;
 379                 }
 380
 381                 p_sys->i_offset = 1; /* To find next startcode */
 382
 383             case STATE_NEXT_SYNC:
 384                 /* Find the next 3 byte startcode 0 0 1*/
 385                 if( block_FindStartcodeFromOffset( &p_sys->bytestream,
 386                       &p_sys->i_offset, p_sys->startcode+1, 3 ) != VLC_SUCCESS)
 387                 {
 388                     /* Need more data */
 389                     return NULL;
 390                 }
 391
 392                 /* Get the new fragment and set the pts/dts */
 393                 p_pic = block_New( p_dec, p_sys->i_offset +1 );
 394                 p_pic->i_pts = p_sys->bytestream.p_block->i_pts;
 395                 p_pic->i_dts = p_sys->bytestream.p_block->i_dts;
 396                 /* Force 4 byte startcode 0 0 0 1 */
 397                 p_pic->p_buffer[0] = 0;
 398
 399                 block_GetBytes( &p_sys->bytestream, &p_pic->p_buffer[1],
 400                                 p_pic->i_buffer-1 );
 401
 402                 /* Remove trailing 0 bytes */
 403                 while( p_pic->i_buffer && (!p_pic->p_buffer[p_pic->i_buffer-1] ) )
 404                     p_pic->i_buffer--;
 405                 p_sys->i_offset = 0;
 406
 407                 /* Parse the NAL */
 408                 if( !( p_pic = ParseNALBlock( p_dec, p_pic ) ) )
 409                 {
 410                     p_sys->i_state = STATE_NOSYNC;
 411                     break;
 412                 }
 413 #if 0
 414                 msg_Dbg( p_dec, "pts="I64Fd" dts="I64Fd,
 415                          p_pic->i_pts, p_pic->i_dts );
 416 #endif
 417
 418                 /* So p_block doesn't get re-added several times */
 419                 *pp_block = block_BytestreamPop( &p_sys->bytestream );
 420
 421                 p_sys->i_state = STATE_NOSYNC;
 422
 423                 return p_pic;
 424         }
 425     }
 426 }
 427
 428 /****************************************************************************
 429  * PacketizeAVC1: Takes VCL blocks of data and creates annexe B type NAL stream
 430  * Will always use 4 byte 0 0 0 1 startcodes
 431  * Will prepend a SPS and PPS before each keyframe
 432  ****************************************************************************/
 433 static block_t *PacketizeAVC1( decoder_t *p_dec, block_t **pp_block )
 434 {
 435     decoder_sys_t *p_sys = p_dec->p_sys;
 436     block_t       *p_block;
 437     block_t       *p_ret = NULL;
 438     uint8_t       *p;
 439
 440     if( !pp_block || !*pp_block )
 441         return NULL;
 442     if( (*pp_block)->i_flags&(BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED) )
 443     {
 444         block_Release( *pp_block );
 445         return NULL;
 446     }
 447
 448     p_block = *pp_block;
 449     *pp_block = NULL;
 450
 451     for( p = p_block->p_buffer; p < &p_block->p_buffer[p_block->i_buffer]; )
 452     {
 453         block_t *p_pic;
 454         int i_size = 0;
 455         int i;
 456
 457         for( i = 0; i < p_sys->i_avcC_length_size; i++ )
 458         {
 459             i_size = (i_size << 8) | (*p++);
 460         }
 461
 462         if( i_size <= 0 ||
 463             i_size > ( p_block->p_buffer + p_block->i_buffer - p ) )
 464         {
 465             msg_Err( p_dec, "Broken frame : size %d is too big", i_size );
 466             break;
 467         }
 468
 469         block_t *p_part = nal_get_annexeb( p_dec, p, i_size );
 470         if( !p_part )
 471             break;
 472         p_part->i_dts = p_block->i_dts;
 473         p_part->i_pts = p_block->i_pts;
 474
 475         /* Parse the NAL */
 476         if( ( p_pic = ParseNALBlock( p_dec, p_part ) ) )
 477         {
 478             block_ChainAppend( &p_ret, p_pic );
 479         }
 480         p += i_size;
 481     }
 482     block_Release( p_block );
 483
 484     return p_ret;
 485 }
 486
 487 static block_t *nal_get_annexeb( decoder_t *p_dec, uint8_t *p, int i_size )
 488 {
 489     block_t *p_nal;
 490
 491     p_nal = block_New( p_dec, 4 + i_size );
 492     if( !p_nal ) return NULL;
 493
 494     /* Add start code */
 495     p_nal->p_buffer[0] = 0x00;
 496     p_nal->p_buffer[1] = 0x00;
 497     p_nal->p_buffer[2] = 0x00;
 498     p_nal->p_buffer[3] = 0x01;
 499
 500     /* Copy nalu */
 501     memcpy( &p_nal->p_buffer[4], p, i_size );
 502
 503     return p_nal;
 504 }
 505
 506 static void nal_get_decoded( uint8_t **pp_ret, int *pi_ret,
 507                              uint8_t *src, int i_src )
 508 {
 509     uint8_t *end = &src[i_src];
 510     uint8_t *dst = malloc( i_src );
 511
 512     *pp_ret = dst;
 513
 514     if( dst )
 515     {
 516         while( src < end )
 517         {
 518             if( src < end - 3 && src[0] == 0x00 && src[1] == 0x00 &&
 519                 src[2] == 0x03 )
 520             {
 521                 *dst++ = 0x00;
 522                 *dst++ = 0x00;
 523
 524                 src += 3;
 525                 continue;
 526             }
 527             *dst++ = *src++;
 528         }
 529     }
 530     *pi_ret = dst - *pp_ret;
 531 }
 532
 533 static inline int bs_read_ue( bs_t *s )
 534 {
 535     int i = 0;
 536
 537     while( bs_read1( s ) == 0 && s->p < s->p_end && i < 32 )
 538     {
 539         i++;
 540     }
 541     return( ( 1 << i) - 1 + bs_read( s, i ) );
 542 }
 543
 544 static inline int bs_read_se( bs_t *s )
 545 {
 546     int val = bs_read_ue( s );
 547
 548     return val&0x01 ? (val+1)/2 : -(val/2);
 549 }
 550
 551 /*****************************************************************************
 552  * ParseNALBlock: parses annexB type NALs
 553  * All p_frag blocks are required to start with 0 0 0 1 4-byte startcode
 554  *****************************************************************************/
 555 static block_t *ParseNALBlock( decoder_t *p_dec, block_t *p_frag )
 556 {
 557     decoder_sys_t *p_sys = p_dec->p_sys;
 558     block_t *p_pic = NULL;
 559
 560     const int i_nal_ref_idc = (p_frag->p_buffer[4] >> 5)&0x03;
 561     const int i_nal_type = p_frag->p_buffer[4]&0x1f;
 562
 563 #define OUTPUT \
 564     do {                                                      \
 565         if( !p_sys->b_header && p_sys->slice.i_frame_type != BLOCK_FLAG_TYPE_I) \
 566             break;                                            \
 567                                                               \
 568         if( p_sys->slice.i_frame_type == BLOCK_FLAG_TYPE_I && p_sys->p_sps && p_sys->p_pps ) \
 569         { \
 570             block_t *p_sps = block_Duplicate( p_sys->p_sps ); \
 571             block_t *p_pps = block_Duplicate( p_sys->p_pps ); \
 572             p_sps->i_dts = p_sys->p_frame->i_dts;           \
 573             p_sps->i_pts = p_sys->p_frame->i_pts;           \
 574             block_ChainAppend( &p_sps, p_pps );               \
 575             block_ChainAppend( &p_sps, p_sys->p_frame );      \
 576             p_sys->b_header = VLC_TRUE;                       \
 577             p_pic = block_ChainGather( p_sps );               \
 578         } else { \
 579             p_pic = block_ChainGather( p_sys->p_frame ); \
 580         } \
 581         p_pic->i_length = 0;    /* FIXME */                   \
 582         p_pic->i_flags |= p_sys->slice.i_frame_type;          \
 583             \
 584         p_sys->slice.i_frame_type = 0;                        \
 585         p_sys->p_frame = NULL;                                \
 586         p_sys->b_slice = VLC_FALSE;                           \
 587     } while(0)
 588
 589     if( p_sys->b_slice && ( !p_sys->b_sps || !p_sys->b_pps ) )
 590     {
 591         block_ChainRelease( p_sys->p_frame );
 592         msg_Warn( p_dec, "waiting for SPS/PPS" );
 593
 594         /* Reset context */
 595         p_sys->slice.i_frame_type = 0;
 596         p_sys->p_frame = NULL;
 597         p_sys->b_slice = VLC_FALSE;
 598     }
 599
 600     if( ( !p_sys->b_sps || !p_sys->b_pps ) &&
 601         i_nal_type >= NAL_SLICE && i_nal_type <= NAL_SLICE_IDR )
 602     {
 603         p_sys->b_slice = VLC_TRUE;
 604         /* Fragment will be discarded later on */
 605     }
 606     else if( i_nal_type >= NAL_SLICE && i_nal_type <= NAL_SLICE_IDR )
 607     {
 608         uint8_t *dec = NULL;
 609         int i_dec = 0, i_first_mb, i_slice_type;
 610         slice_t slice;
 611         vlc_bool_t b_pic;
 612         bs_t s;
 613
 614         /* do not convert the whole frame */
 615         nal_get_decoded( &dec, &i_dec, &p_frag->p_buffer[5],
 616                          __MIN( p_frag->i_buffer - 5, 60 ) );
 617         bs_init( &s, dec, i_dec );
 618
 619         /* first_mb_in_slice */
 620         i_first_mb = bs_read_ue( &s );
 621
 622         /* slice_type */
 623         switch( (i_slice_type = bs_read_ue( &s )) )
 624         {
 625         case 0: case 5:
 626             slice.i_frame_type = BLOCK_FLAG_TYPE_P;
 627             break;
 628         case 1: case 6:
 629             slice.i_frame_type = BLOCK_FLAG_TYPE_B;
 630             break;
 631         case 2: case 7:
 632             slice.i_frame_type = BLOCK_FLAG_TYPE_I;
 633             break;
 634         case 3: case 8: /* SP */
 635             slice.i_frame_type = BLOCK_FLAG_TYPE_P;
 636             break;
 637         case 4: case 9:
 638             slice.i_frame_type = BLOCK_FLAG_TYPE_I;
 639             break;
 640         default:
 641             slice.i_frame_type = 0;
 642             break;
 643         }
 644
 645         /* */
 646         slice.i_nal_type = i_nal_type;
 647         slice.i_nal_ref_idc = i_nal_ref_idc;
 648
 649         slice.i_pic_parameter_set_id = bs_read_ue( &s );
 650         slice.i_frame_num = bs_read( &s, p_sys->i_log2_max_frame_num + 4 );
 651
 652         slice.i_field_pic_flag = 0;
 653         slice.i_bottom_field_flag = -1;
 654         if( !p_sys->b_frame_mbs_only )
 655         {
 656             /* field_pic_flag */
 657             slice.i_field_pic_flag = bs_read( &s, 1 );
 658             if( slice.i_field_pic_flag )
 659                 slice.i_bottom_field_flag = bs_read( &s, 1 );
 660         }
 661
 662         slice.i_idr_pic_id = p_sys->slice.i_idr_pic_id;
 663         if( slice.i_nal_type == NAL_SLICE_IDR )
 664             slice.i_idr_pic_id = bs_read_ue( &s );
 665
 666         slice.i_pic_order_cnt_lsb = -1;
 667         slice.i_delta_pic_order_cnt_bottom = -1;
 668         slice.i_delta_pic_order_cnt0 = 0;
 669         slice.i_delta_pic_order_cnt1 = 0;
 670         if( p_sys->i_pic_order_cnt_type == 0 )
 671         {
 672             slice.i_pic_order_cnt_lsb = bs_read( &s, p_sys->i_log2_max_pic_order_cnt_lsb + 4 );
 673             if( p_sys->i_pic_order_present_flag && !slice.i_field_pic_flag )
 674                 slice.i_delta_pic_order_cnt_bottom = bs_read_se( &s );
 675         }
 676         else if( (p_sys->i_pic_order_cnt_type == 1) &&
 677                  (!p_sys->i_delta_pic_order_always_zero_flag) )
 678         {
 679             slice.i_delta_pic_order_cnt0 = bs_read_se( &s );
 680             if( p_sys->i_pic_order_present_flag && !slice.i_field_pic_flag )
 681                 slice.i_delta_pic_order_cnt1 = bs_read_se( &s );
 682         }
 683
 684         /* Detection of the first VCL NAL unit of a primary coded picture
 685          * (cf. 7.4.1.2.4) */
 686         b_pic = VLC_FALSE;
 687         if( slice.i_frame_num != p_sys->slice.i_frame_num ||
 688             slice.i_pic_parameter_set_id != p_sys->slice.i_pic_parameter_set_id ||
 689             slice.i_field_pic_flag != p_sys->slice.i_field_pic_flag ||
 690             slice.i_nal_ref_idc != p_sys->slice.i_nal_ref_idc )
 691             b_pic = VLC_TRUE;
 692         if( (slice.i_bottom_field_flag != -1) &&
 693             (p_sys->slice.i_bottom_field_flag != -1) &&
 694             (slice.i_bottom_field_flag != p_sys->slice.i_bottom_field_flag) )
 695             b_pic = VLC_TRUE;
 696         if( p_sys->i_pic_order_cnt_type == 0 &&
 697             ( slice.i_pic_order_cnt_lsb != p_sys->slice.i_pic_order_cnt_lsb ||
 698               slice.i_delta_pic_order_cnt_bottom != p_sys->slice.i_delta_pic_order_cnt_bottom ) )
 699             b_pic = VLC_TRUE;
 700         else if( p_sys->i_pic_order_cnt_type == 1 &&
 701                  ( slice.i_delta_pic_order_cnt0 != p_sys->slice.i_delta_pic_order_cnt0 ||
 702                    slice.i_delta_pic_order_cnt1 != p_sys->slice.i_delta_pic_order_cnt1 ) )
 703             b_pic = VLC_TRUE;
 704         if( ( slice.i_nal_type == NAL_SLICE_IDR || p_sys->slice.i_nal_type == NAL_SLICE_IDR ) &&
 705             ( slice.i_nal_type != p_sys->slice.i_nal_type || slice.i_idr_pic_id != p_sys->slice.i_idr_pic_id ) )
 706                 b_pic = VLC_TRUE;
 707
 708         /* */
 709         p_sys->slice = slice;
 710
 711         if( b_pic && p_sys->b_slice )
 712             OUTPUT;
 713
 714         p_sys->b_slice = VLC_TRUE;
 715
 716         free( dec );
 717     }
 718     else if( i_nal_type == NAL_SPS )
 719     {
 720         uint8_t *dec = NULL;
 721         int     i_dec = 0;
 722         bs_t s;
 723         int i_tmp;
 724
 725         if( !p_sys->b_sps ) msg_Dbg( p_dec, "found NAL_SPS" );
 726
 727         p_sys->b_sps = VLC_TRUE;
 728
 729         nal_get_decoded( &dec, &i_dec, &p_frag->p_buffer[5],
 730                          p_frag->i_buffer - 5 );
 731
 732         bs_init( &s, dec, i_dec );
 733         /* Skip profile(8), constraint_set012, reserver(5), level(8) */
 734         bs_skip( &s, 8 + 1+1+1 + 5 + 8 );
 735         /* sps id */
 736         bs_read_ue( &s );
 737         /* Skip i_log2_max_frame_num */
 738         p_sys->i_log2_max_frame_num = bs_read_ue( &s );
 739         if( p_sys->i_log2_max_frame_num > 12)
 740             p_sys->i_log2_max_frame_num = 12;
 741         /* Read poc_type */
 742         p_sys->i_pic_order_cnt_type = bs_read_ue( &s );
 743         if( p_sys->i_pic_order_cnt_type == 0 )
 744         {
 745             /* skip i_log2_max_poc_lsb */
 746             p_sys->i_log2_max_pic_order_cnt_lsb = bs_read_ue( &s );
 747             if( p_sys->i_log2_max_pic_order_cnt_lsb > 12 )
 748                 p_sys->i_log2_max_pic_order_cnt_lsb = 12;
 749         }
 750         else if( p_sys->i_pic_order_cnt_type == 1 )
 751         {
 752             int i_cycle;
 753             /* skip b_delta_pic_order_always_zero */
 754             p_sys->i_delta_pic_order_always_zero_flag = bs_read( &s, 1 );
 755             /* skip i_offset_for_non_ref_pic */
 756             bs_read_se( &s );
 757             /* skip i_offset_for_top_to_bottom_field */
 758             bs_read_se( &s );
 759             /* read i_num_ref_frames_in_poc_cycle */
 760             i_cycle = bs_read_ue( &s );
 761             if( i_cycle > 256 ) i_cycle = 256;
 762             while( i_cycle > 0 )
 763             {
 764                 /* skip i_offset_for_ref_frame */
 765                 bs_read_se(&s );
 766             }
 767         }
 768         /* i_num_ref_frames */
 769         bs_read_ue( &s );
 770         /* b_gaps_in_frame_num_value_allowed */
 771         bs_skip( &s, 1 );
 772
 773         /* Read size */
 774         p_dec->fmt_out.video.i_width  = 16 * ( bs_read_ue( &s ) + 1 );
 775         p_dec->fmt_out.video.i_height = 16 * ( bs_read_ue( &s ) + 1 );
 776
 777         /* b_frame_mbs_only */
 778         p_sys->b_frame_mbs_only = bs_read( &s, 1 );
 779         if( p_sys->b_frame_mbs_only == 0 )
 780         {
 781             bs_skip( &s, 1 );
 782         }
 783         /* b_direct8x8_inference */
 784         bs_skip( &s, 1 );
 785
 786         /* crop */
 787         i_tmp = bs_read( &s, 1 );
 788         if( i_tmp )
 789         {
 790             /* left */
 791             bs_read_ue( &s );
 792             /* right */
 793             bs_read_ue( &s );
 794             /* top */
 795             bs_read_ue( &s );
 796             /* bottom */
 797             bs_read_ue( &s );
 798         }
 799
 800         /* vui */
 801         i_tmp = bs_read( &s, 1 );
 802         if( i_tmp )
 803         {
 804             /* read the aspect ratio part if any FIXME check it */
 805             i_tmp = bs_read( &s, 1 );
 806             if( i_tmp )
 807             {
 808                 static const struct { int w, h; } sar[14] =
 809                 {
 810                     { 0,   0 }, { 1,   1 }, { 12, 11 }, { 10, 11 },
 811                     { 16, 11 }, { 40, 33 }, { 24, 11 }, { 20, 11 },
 812                     { 32, 11 }, { 80, 33 }, { 18, 11 }, { 15, 11 },
 813                     { 64, 33 }, { 160,99 },
 814                 };
 815                 int i_sar = bs_read( &s, 8 );
 816                 int w, h;
 817
 818                 if( i_sar < 14 )
 819                 {
 820                     w = sar[i_sar].w;
 821                     h = sar[i_sar].h;
 822                 }
 823                 else
 824                 {
 825                     w = bs_read( &s, 16 );
 826                     h = bs_read( &s, 16 );
 827                 }
 828                 if( h != 0 )
 829                     p_dec->fmt_out.video.i_aspect = VOUT_ASPECT_FACTOR * w /
 830                         h * p_dec->fmt_out.video.i_width /
 831                         p_dec->fmt_out.video.i_height;
 832                 else
 833                     p_dec->fmt_out.video.i_aspect = VOUT_ASPECT_FACTOR;
 834             }
 835         }
 836
 837         free( dec );
 838
 839         if( p_sys->b_slice ) OUTPUT;
 840
 841         /* We have a new SPS */
 842         if( p_sys->p_sps ) block_Release( p_sys->p_sps );
 843         p_sys->p_sps = p_frag;
 844
 845         /* Do not append the SPS because we will insert it on keyframes */
 846         return p_pic;
 847     }
 848     else if( i_nal_type == NAL_PPS )
 849     {
 850         bs_t s;
 851
 852         bs_init( &s, &p_frag->p_buffer[5], p_frag->i_buffer - 5 );
 853         bs_read_ue( &s ); // pps id
 854         bs_read_ue( &s ); // sps id
 855         bs_skip( &s, 1 ); // entropy coding mode flag
 856         p_sys->i_pic_order_present_flag = bs_read( &s, 1 );
 857
 858         if( !p_sys->b_pps ) msg_Dbg( p_dec, "found NAL_PPS" );
 859         p_sys->b_pps = VLC_TRUE;
 860
 861         /* TODO */
 862
 863         if( p_sys->b_slice ) OUTPUT;
 864
 865         /* We have a new PPS */
 866         if( p_sys->p_pps ) block_Release( p_sys->p_pps );
 867         p_sys->p_pps = p_frag;
 868
 869         /* Do not append the PPS because we will insert it on keyframes */
 870         return p_pic;
 871     }
 872     else if( i_nal_type == NAL_AU_DELIMITER ||
 873              i_nal_type == NAL_SEI ||
 874              ( i_nal_type >= 13 && i_nal_type <= 18 ) )
 875     {
 876         if( p_sys->b_slice ) OUTPUT;
 877     }
 878
 879 #undef OUTPUT
 880
 881     /* Append the block */
 882     block_ChainAppend( &p_sys->p_frame, p_frag );
 883
 884     return p_pic;
 885 }