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             int i_length = GetWBE( p );
 227             block_t *p_sps = nal_get_annexeb( p_dec, p + 2, i_length );
 228
 229             p_sys->p_sps = block_Duplicate( p_sps );
 230             p_sps->i_pts = p_sps->i_dts = mdate();
 231             ParseNALBlock( p_dec, p_sps );
 232             p += 2 + i_length;
 233         }
 234         /* Read PPS */
 235         i_pps = *p++;
 236         for( i = 0; i < i_pps; i++ )
 237         {
 238             int i_length = GetWBE( p );
 239             block_t *p_pps = nal_get_annexeb( p_dec, p + 2, i_length );
 240
 241             p_sys->p_pps = block_Duplicate( p_pps );
 242             p_pps->i_pts = p_pps->i_dts = mdate();
 243             ParseNALBlock( p_dec, p_pps );
 244             p += 2 + i_length;
 245         }
 246         msg_Dbg( p_dec, "avcC length size=%d, sps=%d, pps=%d",
 247                  p_sys->i_avcC_length_size, i_sps, i_pps );
 248
 249         /* FIXME: FFMPEG isn't happy at all if you leave this */
 250         if( p_dec->fmt_out.i_extra ) free( p_dec->fmt_out.p_extra );
 251         p_dec->fmt_out.i_extra = 0; p_dec->fmt_out.p_extra = NULL;
 252
 253         /* Set the new extradata */
 254         p_dec->fmt_out.i_extra = p_sys->p_pps->i_buffer + p_sys->p_sps->i_buffer;
 255         p_dec->fmt_out.p_extra = (uint8_t*)malloc( p_dec->fmt_out.i_extra );
 256         if( p_dec->fmt_out.p_extra )
 257         {
 258             memcpy( (uint8_t*)p_dec->fmt_out.p_extra, p_sys->p_sps->p_buffer, p_sys->p_sps->i_buffer);
 259             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);
 260             p_sys->b_header = VLC_TRUE;
 261         }
 262         else p_dec->fmt_out.i_extra = 0;
 263
 264         /* Set callback */
 265         p_dec->pf_packetize = PacketizeAVC1;
 266     }
 267     else
 268     {
 269         /* This type of stream contains data with 3 of 4 byte startcodes
 270          * The fmt_in.p_extra MAY contain SPS/PPS with 4 byte startcodes
 271          * The fmt_out.p_extra should be the same */
 272
 273         /* Set callback */
 274         p_dec->pf_packetize = Packetize;
 275
 276         /* */
 277         if( p_dec->fmt_in.i_extra > 0 )
 278         {
 279             block_t *p_init = block_New( p_dec, p_dec->fmt_in.i_extra );
 280             block_t *p_pic;
 281
 282             memcpy( p_init->p_buffer, p_dec->fmt_in.p_extra,
 283                     p_dec->fmt_in.i_extra );
 284
 285             while( ( p_pic = Packetize( p_dec, &p_init ) ) )
 286             {
 287                 /* Should not occur because we should only receive SPS/PPS */
 288                 block_Release( p_pic );
 289             }
 290         }
 291     }
 292
 293     return VLC_SUCCESS;
 294 }
 295
 296 /*****************************************************************************
 297  * Close: clean up the packetizer
 298  *****************************************************************************/
 299 static void Close( vlc_object_t *p_this )
 300 {
 301     decoder_t *p_dec = (decoder_t*)p_this;
 302     decoder_sys_t *p_sys = p_dec->p_sys;
 303
 304     if( p_sys->p_frame ) block_ChainRelease( p_sys->p_frame );
 305     if( p_sys->p_sps ) block_Release( p_sys->p_sps );
 306     if( p_sys->p_pps ) block_Release( p_sys->p_pps );
 307     block_BytestreamRelease( &p_sys->bytestream );
 308     free( p_sys );
 309 }
 310
 311 /****************************************************************************
 312  * Packetize: the whole thing
 313  * Search for the startcodes 3 or more bytes
 314  * Feed ParseNALBlock ALWAYS with 4 byte startcode prepended NALs
 315  ****************************************************************************/
 316 static block_t *Packetize( decoder_t *p_dec, block_t **pp_block )
 317 {
 318     decoder_sys_t *p_sys = p_dec->p_sys;
 319     block_t       *p_pic;
 320
 321     if( !pp_block || !*pp_block )
 322         return NULL;
 323
 324     if( (*pp_block)->i_flags&(BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED) )
 325     {
 326         if( (*pp_block)->i_flags&BLOCK_FLAG_CORRUPTED )
 327         {
 328             p_sys->i_state = STATE_NOSYNC;
 329             block_BytestreamFlush( &p_sys->bytestream );
 330
 331             if( p_sys->p_frame )
 332                 block_ChainRelease( p_sys->p_frame );
 333             p_sys->p_frame = NULL;
 334             p_sys->slice.i_frame_type = 0;
 335             p_sys->b_slice = VLC_FALSE;
 336         }
 337         block_Release( *pp_block );
 338         return NULL;
 339     }
 340
 341     block_BytestreamPush( &p_sys->bytestream, *pp_block );
 342
 343     for( ;; )
 344     {
 345         switch( p_sys->i_state )
 346         {
 347             case STATE_NOSYNC:
 348                 /* Skip until 3 byte startcode 0 0 1 */
 349                 if( block_FindStartcodeFromOffset( &p_sys->bytestream,
 350                       &p_sys->i_offset, p_sys->startcode+1, 3 ) == VLC_SUCCESS)
 351                 {
 352                     p_sys->i_state = STATE_NEXT_SYNC;
 353                 }
 354
 355                 if( p_sys->i_offset )
 356                 {
 357                     /* skip the data */
 358                     block_SkipBytes( &p_sys->bytestream, p_sys->i_offset );
 359                     p_sys->i_offset = 0;
 360                     block_BytestreamFlush( &p_sys->bytestream );
 361                 }
 362
 363                 if( p_sys->i_state != STATE_NEXT_SYNC )
 364                 {
 365                     /* Need more data */
 366                     return NULL;
 367                 }
 368
 369                 p_sys->i_offset = 1; /* To find next startcode */
 370
 371             case STATE_NEXT_SYNC:
 372                 /* Find the next 3 byte startcode 0 0 1*/
 373                 if( block_FindStartcodeFromOffset( &p_sys->bytestream,
 374                       &p_sys->i_offset, p_sys->startcode+1, 3 ) != VLC_SUCCESS)
 375                 {
 376                     /* Need more data */
 377                     return NULL;
 378                 }
 379
 380                 /* Get the new fragment and set the pts/dts */
 381                 p_pic = block_New( p_dec, p_sys->i_offset +1 );
 382                 p_pic->i_pts = p_sys->bytestream.p_block->i_pts;
 383                 p_pic->i_dts = p_sys->bytestream.p_block->i_dts;
 384                 /* Force 4 byte startcode 0 0 0 1 */
 385                 p_pic->p_buffer[0] = 0;
 386
 387                 block_GetBytes( &p_sys->bytestream, &p_pic->p_buffer[1],
 388                                 p_pic->i_buffer-1 );
 389
 390                 /* Remove trailing 0 bytes */
 391                 while( p_pic->i_buffer && (!p_pic->p_buffer[p_pic->i_buffer-1] ) )
 392                     p_pic->i_buffer--;
 393                 p_sys->i_offset = 0;
 394
 395                 /* Parse the NAL */
 396                 if( !( p_pic = ParseNALBlock( p_dec, p_pic ) ) )
 397                 {
 398                     p_sys->i_state = STATE_NOSYNC;
 399                     break;
 400                 }
 401 #if 0
 402                 msg_Dbg( p_dec, "pts="I64Fd" dts="I64Fd,
 403                          p_pic->i_pts, p_pic->i_dts );
 404 #endif
 405
 406                 /* So p_block doesn't get re-added several times */
 407                 *pp_block = block_BytestreamPop( &p_sys->bytestream );
 408
 409                 p_sys->i_state = STATE_NOSYNC;
 410
 411                 return p_pic;
 412         }
 413     }
 414 }
 415
 416 /****************************************************************************
 417  * PacketizeAVC1: Takes VCL blocks of data and creates annexe B type NAL stream
 418  * Will always use 4 byte 0 0 0 1 startcodes
 419  * Will prepend a SPS and PPS before each keyframe
 420  ****************************************************************************/
 421 static block_t *PacketizeAVC1( decoder_t *p_dec, block_t **pp_block )
 422 {
 423     decoder_sys_t *p_sys = p_dec->p_sys;
 424     block_t       *p_block;
 425     block_t       *p_ret = NULL;
 426     uint8_t       *p;
 427
 428     if( !pp_block || !*pp_block )
 429         return NULL;
 430     if( (*pp_block)->i_flags&(BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED) )
 431     {
 432         block_Release( *pp_block );
 433         return NULL;
 434     }
 435
 436     p_block = *pp_block;
 437     *pp_block = NULL;
 438
 439     for( p = p_block->p_buffer; p < &p_block->p_buffer[p_block->i_buffer]; )
 440     {
 441         block_t *p_pic;
 442         int i_size = 0;
 443         int i;
 444
 445         for( i = 0; i < p_sys->i_avcC_length_size; i++ )
 446         {
 447             i_size = (i_size << 8) | (*p++);
 448         }
 449
 450         if( i_size <= 0 ||
 451             i_size >= ( p - p_block->p_buffer + p_block->i_buffer ) )
 452         {
 453             msg_Err( p_dec, "Broken frame : size %d is too big", i_size );
 454             break;
 455         }
 456
 457         block_t *p_part = nal_get_annexeb( p_dec, p, i_size );
 458         if( !p_part )
 459             break;
 460         p_part->i_dts = p_block->i_dts;
 461         p_part->i_pts = p_block->i_pts;
 462
 463         /* Parse the NAL */
 464         if( ( p_pic = ParseNALBlock( p_dec, p_part ) ) )
 465         {
 466             block_ChainAppend( &p_ret, p_pic );
 467         }
 468         p += i_size;
 469     }
 470     block_Release( p_block );
 471
 472     return p_ret;
 473 }
 474
 475 static block_t *nal_get_annexeb( decoder_t *p_dec, uint8_t *p, int i_size )
 476 {
 477     block_t *p_nal;
 478
 479     p_nal = block_New( p_dec, 4 + i_size );
 480     if( !p_nal ) return NULL;
 481
 482     /* Add start code */
 483     p_nal->p_buffer[0] = 0x00;
 484     p_nal->p_buffer[1] = 0x00;
 485     p_nal->p_buffer[2] = 0x00;
 486     p_nal->p_buffer[3] = 0x01;
 487
 488     /* Copy nalu */
 489     memcpy( &p_nal->p_buffer[4], p, i_size );
 490
 491     return p_nal;
 492 }
 493
 494 static void nal_get_decoded( uint8_t **pp_ret, int *pi_ret,
 495                              uint8_t *src, int i_src )
 496 {
 497     uint8_t *end = &src[i_src];
 498     uint8_t *dst = malloc( i_src );
 499
 500     *pp_ret = dst;
 501
 502     if( dst )
 503     {
 504         while( src < end )
 505         {
 506             if( src < end - 3 && src[0] == 0x00 && src[1] == 0x00 &&
 507                 src[2] == 0x03 )
 508             {
 509                 *dst++ = 0x00;
 510                 *dst++ = 0x00;
 511
 512                 src += 3;
 513                 continue;
 514             }
 515             *dst++ = *src++;
 516         }
 517     }
 518     *pi_ret = dst - *pp_ret;
 519 }
 520
 521 static inline int bs_read_ue( bs_t *s )
 522 {
 523     int i = 0;
 524
 525     while( bs_read1( s ) == 0 && s->p < s->p_end && i < 32 )
 526     {
 527         i++;
 528     }
 529     return( ( 1 << i) - 1 + bs_read( s, i ) );
 530 }
 531
 532 static inline int bs_read_se( bs_t *s )
 533 {
 534     int val = bs_read_ue( s );
 535
 536     return val&0x01 ? (val+1)/2 : -(val/2);
 537 }
 538
 539 /*****************************************************************************
 540  * ParseNALBlock: parses annexB type NALs
 541  * All p_frag blocks are required to start with 0 0 0 1 4-byte startcode
 542  *****************************************************************************/
 543 static block_t *ParseNALBlock( decoder_t *p_dec, block_t *p_frag )
 544 {
 545     decoder_sys_t *p_sys = p_dec->p_sys;
 546     block_t *p_pic = NULL;
 547
 548     const int i_nal_ref_idc = (p_frag->p_buffer[4] >> 5)&0x03;
 549     const int i_nal_type = p_frag->p_buffer[4]&0x1f;
 550
 551 #define OUTPUT \
 552     do {                                                      \
 553         if( !p_sys->b_header && p_sys->slice.i_frame_type != BLOCK_FLAG_TYPE_I) \
 554             break;                                            \
 555                                                               \
 556         if( p_sys->slice.i_frame_type == BLOCK_FLAG_TYPE_I && p_sys->p_sps && p_sys->p_pps ) \
 557         { \
 558             block_t *p_sps = block_Duplicate( p_sys->p_sps ); \
 559             block_t *p_pps = block_Duplicate( p_sys->p_pps ); \
 560             p_sps->i_dts = p_sys->p_frame->i_dts;           \
 561             p_sps->i_pts = p_sys->p_frame->i_pts;           \
 562             block_ChainAppend( &p_sps, p_pps );               \
 563             block_ChainAppend( &p_sps, p_sys->p_frame );      \
 564             p_sys->b_header = VLC_TRUE;                       \
 565             p_pic = block_ChainGather( p_sps );               \
 566         } else { \
 567             p_pic = block_ChainGather( p_sys->p_frame ); \
 568         } \
 569         p_pic->i_length = 0;    /* FIXME */                   \
 570         p_pic->i_flags |= p_sys->slice.i_frame_type;          \
 571             \
 572         p_sys->slice.i_frame_type = 0;                        \
 573         p_sys->p_frame = NULL;                                \
 574         p_sys->b_slice = VLC_FALSE;                           \
 575     } while(0)
 576
 577     if( p_sys->b_slice && ( !p_sys->b_sps || !p_sys->b_pps ) )
 578     {
 579         block_ChainRelease( p_sys->p_frame );
 580         msg_Warn( p_dec, "waiting for SPS/PPS" );
 581
 582         /* Reset context */
 583         p_sys->slice.i_frame_type = 0;
 584         p_sys->p_frame = NULL;
 585         p_sys->b_slice = VLC_FALSE;
 586     }
 587
 588     if( ( !p_sys->b_sps || !p_sys->b_pps ) &&
 589         i_nal_type >= NAL_SLICE && i_nal_type <= NAL_SLICE_IDR )
 590     {
 591         p_sys->b_slice = VLC_TRUE;
 592         /* Fragment will be discarded later on */
 593     }
 594     else if( i_nal_type >= NAL_SLICE && i_nal_type <= NAL_SLICE_IDR )
 595     {
 596         uint8_t *dec = NULL;
 597         int i_dec = 0, i_first_mb, i_slice_type;
 598         slice_t slice;
 599         vlc_bool_t b_pic;
 600         bs_t s;
 601
 602         /* do not convert the whole frame */
 603         nal_get_decoded( &dec, &i_dec, &p_frag->p_buffer[5],
 604                          __MIN( p_frag->i_buffer - 5, 60 ) );
 605         bs_init( &s, dec, i_dec );
 606
 607         /* first_mb_in_slice */
 608         i_first_mb = bs_read_ue( &s );
 609
 610         /* slice_type */
 611         switch( (i_slice_type = bs_read_ue( &s )) )
 612         {
 613         case 0: case 5:
 614             slice.i_frame_type = BLOCK_FLAG_TYPE_P;
 615             break;
 616         case 1: case 6:
 617             slice.i_frame_type = BLOCK_FLAG_TYPE_B;
 618             break;
 619         case 2: case 7:
 620             slice.i_frame_type = BLOCK_FLAG_TYPE_I;
 621             break;
 622         case 3: case 8: /* SP */
 623             slice.i_frame_type = BLOCK_FLAG_TYPE_P;
 624             break;
 625         case 4: case 9:
 626             slice.i_frame_type = BLOCK_FLAG_TYPE_I;
 627             break;
 628         default:
 629             slice.i_frame_type = 0;
 630             break;
 631         }
 632
 633         /* */
 634         slice.i_nal_type = i_nal_type;
 635         slice.i_nal_ref_idc = i_nal_ref_idc;
 636
 637         slice.i_pic_parameter_set_id = bs_read_ue( &s );
 638         slice.i_frame_num = bs_read( &s, p_sys->i_log2_max_frame_num + 4 );
 639
 640         slice.i_field_pic_flag = 0;
 641         slice.i_bottom_field_flag = -1;
 642         if( !p_sys->b_frame_mbs_only )
 643         {
 644             /* field_pic_flag */
 645             slice.i_field_pic_flag = bs_read( &s, 1 );
 646             if( slice.i_field_pic_flag )
 647                 slice.i_bottom_field_flag = bs_read( &s, 1 );
 648         }
 649
 650         slice.i_idr_pic_id = p_sys->slice.i_idr_pic_id;
 651         if( slice.i_nal_type == NAL_SLICE_IDR )
 652             slice.i_idr_pic_id = bs_read_ue( &s );
 653
 654         slice.i_pic_order_cnt_lsb = -1;
 655         slice.i_delta_pic_order_cnt_bottom = -1;
 656         slice.i_delta_pic_order_cnt0 = 0;
 657         slice.i_delta_pic_order_cnt1 = 0;
 658         if( p_sys->i_pic_order_cnt_type == 0 )
 659         {
 660             slice.i_pic_order_cnt_lsb = bs_read( &s, p_sys->i_log2_max_pic_order_cnt_lsb + 4 );
 661             if( p_sys->i_pic_order_present_flag && !slice.i_field_pic_flag )
 662                 slice.i_delta_pic_order_cnt_bottom = bs_read_se( &s );
 663         }
 664         else if( (p_sys->i_pic_order_cnt_type == 1) &&
 665                  (!p_sys->i_delta_pic_order_always_zero_flag) )
 666         {
 667             slice.i_delta_pic_order_cnt0 = bs_read_se( &s );
 668             if( p_sys->i_pic_order_present_flag && !slice.i_field_pic_flag )
 669                 slice.i_delta_pic_order_cnt1 = bs_read_se( &s );
 670         }
 671
 672         /* Detection of the first VCL NAL unit of a primary coded picture
 673          * (cf. 7.4.1.2.4) */
 674         b_pic = VLC_FALSE;
 675         if( slice.i_frame_num != p_sys->slice.i_frame_num ||
 676             slice.i_pic_parameter_set_id != p_sys->slice.i_pic_parameter_set_id ||
 677             slice.i_field_pic_flag != p_sys->slice.i_field_pic_flag ||
 678             slice.i_nal_ref_idc != p_sys->slice.i_nal_ref_idc )
 679             b_pic = VLC_TRUE;
 680         if( (slice.i_bottom_field_flag != -1) &&
 681             (p_sys->slice.i_bottom_field_flag != -1) &&
 682             (slice.i_bottom_field_flag != p_sys->slice.i_bottom_field_flag) )
 683             b_pic = VLC_TRUE;
 684         if( p_sys->i_pic_order_cnt_type == 0 &&
 685             ( slice.i_pic_order_cnt_lsb != p_sys->slice.i_pic_order_cnt_lsb ||
 686               slice.i_delta_pic_order_cnt_bottom != p_sys->slice.i_delta_pic_order_cnt_bottom ) )
 687             b_pic = VLC_TRUE;
 688         else if( p_sys->i_pic_order_cnt_type == 1 &&
 689                  ( slice.i_delta_pic_order_cnt0 != p_sys->slice.i_delta_pic_order_cnt0 ||
 690                    slice.i_delta_pic_order_cnt1 != p_sys->slice.i_delta_pic_order_cnt1 ) )
 691             b_pic = VLC_TRUE;
 692         if( ( slice.i_nal_type == NAL_SLICE_IDR || p_sys->slice.i_nal_type == NAL_SLICE_IDR ) &&
 693             ( slice.i_nal_type != p_sys->slice.i_nal_type || slice.i_idr_pic_id != p_sys->slice.i_idr_pic_id ) )
 694                 b_pic = VLC_TRUE;
 695
 696         /* */
 697         p_sys->slice = slice;
 698
 699         if( b_pic && p_sys->b_slice )
 700             OUTPUT;
 701
 702         p_sys->b_slice = VLC_TRUE;
 703
 704         free( dec );
 705     }
 706     else if( i_nal_type == NAL_SPS )
 707     {
 708         uint8_t *dec = NULL;
 709         int     i_dec = 0;
 710         bs_t s;
 711         int i_tmp;
 712
 713         if( !p_sys->b_sps ) msg_Dbg( p_dec, "found NAL_SPS" );
 714
 715         p_sys->b_sps = VLC_TRUE;
 716
 717         nal_get_decoded( &dec, &i_dec, &p_frag->p_buffer[5],
 718                          p_frag->i_buffer - 5 );
 719
 720         bs_init( &s, dec, i_dec );
 721         /* Skip profile(8), constraint_set012, reserver(5), level(8) */
 722         bs_skip( &s, 8 + 1+1+1 + 5 + 8 );
 723         /* sps id */
 724         bs_read_ue( &s );
 725         /* Skip i_log2_max_frame_num */
 726         p_sys->i_log2_max_frame_num = bs_read_ue( &s );
 727         if( p_sys->i_log2_max_frame_num > 12)
 728             p_sys->i_log2_max_frame_num = 12;
 729         /* Read poc_type */
 730         p_sys->i_pic_order_cnt_type = bs_read_ue( &s );
 731         if( p_sys->i_pic_order_cnt_type == 0 )
 732         {
 733             /* skip i_log2_max_poc_lsb */
 734             p_sys->i_log2_max_pic_order_cnt_lsb = bs_read_ue( &s );
 735             if( p_sys->i_log2_max_pic_order_cnt_lsb > 12 )
 736                 p_sys->i_log2_max_pic_order_cnt_lsb = 12;
 737         }
 738         else if( p_sys->i_pic_order_cnt_type == 1 )
 739         {
 740             int i_cycle;
 741             /* skip b_delta_pic_order_always_zero */
 742             p_sys->i_delta_pic_order_always_zero_flag = bs_read( &s, 1 );
 743             /* skip i_offset_for_non_ref_pic */
 744             bs_read_se( &s );
 745             /* skip i_offset_for_top_to_bottom_field */
 746             bs_read_se( &s );
 747             /* read i_num_ref_frames_in_poc_cycle */
 748             i_cycle = bs_read_ue( &s );
 749             if( i_cycle > 256 ) i_cycle = 256;
 750             while( i_cycle > 0 )
 751             {
 752                 /* skip i_offset_for_ref_frame */
 753                 bs_read_se(&s );
 754             }
 755         }
 756         /* i_num_ref_frames */
 757         bs_read_ue( &s );
 758         /* b_gaps_in_frame_num_value_allowed */
 759         bs_skip( &s, 1 );
 760
 761         /* Read size */
 762         p_dec->fmt_out.video.i_width  = 16 * ( bs_read_ue( &s ) + 1 );
 763         p_dec->fmt_out.video.i_height = 16 * ( bs_read_ue( &s ) + 1 );
 764
 765         /* b_frame_mbs_only */
 766         p_sys->b_frame_mbs_only = bs_read( &s, 1 );
 767         if( p_sys->b_frame_mbs_only == 0 )
 768         {
 769             bs_skip( &s, 1 );
 770         }
 771         /* b_direct8x8_inference */
 772         bs_skip( &s, 1 );
 773
 774         /* crop */
 775         i_tmp = bs_read( &s, 1 );
 776         if( i_tmp )
 777         {
 778             /* left */
 779             bs_read_ue( &s );
 780             /* right */
 781             bs_read_ue( &s );
 782             /* top */
 783             bs_read_ue( &s );
 784             /* bottom */
 785             bs_read_ue( &s );
 786         }
 787
 788         /* vui */
 789         i_tmp = bs_read( &s, 1 );
 790         if( i_tmp )
 791         {
 792             /* read the aspect ratio part if any FIXME check it */
 793             i_tmp = bs_read( &s, 1 );
 794             if( i_tmp )
 795             {
 796                 static const struct { int w, h; } sar[14] =
 797                 {
 798                     { 0,   0 }, { 1,   1 }, { 12, 11 }, { 10, 11 },
 799                     { 16, 11 }, { 40, 33 }, { 24, 11 }, { 20, 11 },
 800                     { 32, 11 }, { 80, 33 }, { 18, 11 }, { 15, 11 },
 801                     { 64, 33 }, { 160,99 },
 802                 };
 803                 int i_sar = bs_read( &s, 8 );
 804                 int w, h;
 805
 806                 if( i_sar < 14 )
 807                 {
 808                     w = sar[i_sar].w;
 809                     h = sar[i_sar].h;
 810                 }
 811                 else
 812                 {
 813                     w = bs_read( &s, 16 );
 814                     h = bs_read( &s, 16 );
 815                 }
 816                 if( h != 0 )
 817                     p_dec->fmt_out.video.i_aspect = VOUT_ASPECT_FACTOR * w /
 818                         h * p_dec->fmt_out.video.i_width /
 819                         p_dec->fmt_out.video.i_height;
 820                 else
 821                     p_dec->fmt_out.video.i_aspect = VOUT_ASPECT_FACTOR;
 822             }
 823         }
 824
 825         free( dec );
 826
 827         if( p_sys->b_slice ) OUTPUT;
 828
 829         /* We have a new SPS */
 830         if( p_sys->p_sps ) block_Release( p_sys->p_sps );
 831         p_sys->p_sps = p_frag;
 832
 833         /* Do not append the SPS because we will insert it on keyframes */
 834         return p_pic;
 835     }
 836     else if( i_nal_type == NAL_PPS )
 837     {
 838         bs_t s;
 839
 840         bs_init( &s, &p_frag->p_buffer[5], p_frag->i_buffer - 5 );
 841         bs_read_ue( &s ); // pps id
 842         bs_read_ue( &s ); // sps id
 843         bs_skip( &s, 1 ); // entropy coding mode flag
 844         p_sys->i_pic_order_present_flag = bs_read( &s, 1 );
 845
 846         if( !p_sys->b_pps ) msg_Dbg( p_dec, "found NAL_PPS" );
 847         p_sys->b_pps = VLC_TRUE;
 848
 849         /* TODO */
 850
 851         if( p_sys->b_slice ) OUTPUT;
 852
 853         /* We have a new PPS */
 854         if( p_sys->p_pps ) block_Release( p_sys->p_pps );
 855         p_sys->p_pps = p_frag;
 856
 857         /* Do not append the PPS because we will insert it on keyframes */
 858         return p_pic;
 859     }
 860     else if( i_nal_type == NAL_AU_DELIMITER ||
 861              i_nal_type == NAL_SEI ||
 862              ( i_nal_type >= 13 && i_nal_type <= 18 ) )
 863     {
 864         if( p_sys->b_slice ) OUTPUT;
 865     }
 866
 867 #undef OUTPUT
 868
 869     /* Append the block */
 870     block_ChainAppend( &p_sys->p_frame, p_frag );
 871
 872     return p_pic;
 873 }