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_common.h>
  36 #include <vlc_plugin.h>
  37 #include <vlc_sout.h>
  38 #include <vlc_codec.h>
  39 #include <vlc_block.h>
  40
  41 #include "vlc_block_helper.h"
  42 #include "vlc_bits.h"
  43
  44 /*****************************************************************************
  45  * Module descriptor
  46  *****************************************************************************/
  47 static int  Open ( vlc_object_t * );
  48 static void Close( vlc_object_t * );
  49
  50 vlc_module_begin();
  51     set_category( CAT_SOUT );
  52     set_subcategory( SUBCAT_SOUT_PACKETIZER );
  53     set_description( N_("H.264 video packetizer") );
  54     set_capability( "packetizer", 50 );
  55     set_callbacks( Open, Close );
  56 vlc_module_end();
  57
  58
  59 /****************************************************************************
  60  * Local prototypes
  61  ****************************************************************************/
  62 static block_t *Packetize( decoder_t *, block_t ** );
  63 static block_t *PacketizeAVC1( decoder_t *, block_t ** );
  64
  65 typedef struct
  66 {
  67     int i_nal_type;
  68     int i_nal_ref_idc;
  69
  70     int i_frame_type;
  71     int i_pic_parameter_set_id;
  72     int i_frame_num;
  73
  74     int i_field_pic_flag;
  75     int i_bottom_field_flag;
  76
  77     int i_idr_pic_id;
  78
  79     int i_pic_order_cnt_lsb;
  80     int i_delta_pic_order_cnt_bottom;
  81
  82     int i_delta_pic_order_cnt0;
  83     int i_delta_pic_order_cnt1;
  84 } slice_t;
  85
  86 struct decoder_sys_t
  87 {
  88     block_bytestream_t bytestream;
  89
  90     int     i_state;
  91     size_t  i_offset;
  92     uint8_t startcode[4];
  93
  94     bool b_slice;
  95     block_t    *p_frame;
  96
  97     bool   b_sps;
  98     bool   b_pps;
  99     bool   b_header;
 100
 101     /* avcC data */
 102     int i_avcC_length_size;
 103     block_t *p_sps;
 104     block_t *p_pps;
 105
 106     /* Useful values of the Sequence Parameter Set */
 107     int i_log2_max_frame_num;
 108     int b_frame_mbs_only;
 109     int i_pic_order_cnt_type;
 110     int i_delta_pic_order_always_zero_flag;
 111     int i_log2_max_pic_order_cnt_lsb;
 112
 113     /* Value from Picture Parameter Set */
 114     int i_pic_order_present_flag;
 115
 116     /* Useful values of the Slice Header */
 117     slice_t slice;
 118 };
 119
 120 enum
 121 {
 122     STATE_NOSYNC,
 123     STATE_NEXT_SYNC,
 124 };
 125
 126 enum nal_unit_type_e
 127 {
 128     NAL_UNKNOWN = 0,
 129     NAL_SLICE   = 1,
 130     NAL_SLICE_DPA   = 2,
 131     NAL_SLICE_DPB   = 3,
 132     NAL_SLICE_DPC   = 4,
 133     NAL_SLICE_IDR   = 5,    /* ref_idc != 0 */
 134     NAL_SEI         = 6,    /* ref_idc == 0 */
 135     NAL_SPS         = 7,
 136     NAL_PPS         = 8,
 137     NAL_AU_DELIMITER= 9
 138     /* ref_idc == 0 for 6,9,10,11,12 */
 139 };
 140
 141 enum nal_priority_e
 142 {
 143     NAL_PRIORITY_DISPOSABLE = 0,
 144     NAL_PRIORITY_LOW        = 1,
 145     NAL_PRIORITY_HIGH       = 2,
 146     NAL_PRIORITY_HIGHEST    = 3,
 147 };
 148
 149 static block_t *ParseNALBlock( decoder_t *, block_t * );
 150
 151 static block_t *nal_get_annexeb( decoder_t *, uint8_t *p, int );
 152
 153 /*****************************************************************************
 154  * Open: probe the packetizer and return score
 155  * When opening after demux, the packetizer is only loaded AFTER the decoder
 156  * That means that what you set in fmt_out is ignored by the decoder in this special case
 157  *****************************************************************************/
 158 static int Open( vlc_object_t *p_this )
 159 {
 160     decoder_t     *p_dec = (decoder_t*)p_this;
 161     decoder_sys_t *p_sys;
 162
 163     if( p_dec->fmt_in.i_codec != VLC_FOURCC( 'h', '2', '6', '4') &&
 164         p_dec->fmt_in.i_codec != VLC_FOURCC( 'H', '2', '6', '4') &&
 165         p_dec->fmt_in.i_codec != VLC_FOURCC( 'V', 'S', 'S', 'H') &&
 166         p_dec->fmt_in.i_codec != VLC_FOURCC( 'v', 's', 's', 'h') &&
 167         p_dec->fmt_in.i_codec != VLC_FOURCC( 'D', 'A', 'V', 'C') &&
 168         ( p_dec->fmt_in.i_codec != VLC_FOURCC( 'a', 'v', 'c', '1') ||
 169           p_dec->fmt_in.i_extra < 7 ) )
 170     {
 171         return VLC_EGENERIC;
 172     }
 173
 174     /* Allocate the memory needed to store the decoder's structure */
 175     if( ( p_dec->p_sys = p_sys = malloc( sizeof(decoder_sys_t) ) ) == NULL )
 176     {
 177         return VLC_ENOMEM;
 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 = false;
 187     p_sys->p_frame = NULL;
 188     p_sys->b_sps   = false;
 189     p_sys->b_pps   = false;
 190     p_sys->p_sps   = 0;
 191     p_sys->p_pps   = 0;
 192     p_sys->b_header= 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             ParseNALBlock( p_dec, p_sps );
 236             p += i_length;
 237         }
 238         /* Read PPS */
 239         i_pps = *p++;
 240         for( i = 0; i < i_pps; i++ )
 241         {
 242             uint16_t i_length = GetWBE( p ); p += 2;
 243             if( i_length >
 244                 (uint8_t*)p_dec->fmt_in.p_extra + p_dec->fmt_in.i_extra - p )
 245             {
 246                 return VLC_EGENERIC;
 247             }
 248             block_t *p_pps = nal_get_annexeb( p_dec, p, i_length );
 249             if( !p_pps )
 250                 return VLC_EGENERIC;
 251             ParseNALBlock( p_dec, p_pps );
 252             p += i_length;
 253         }
 254         msg_Dbg( p_dec, "avcC length size=%d, sps=%d, pps=%d",
 255                  p_sys->i_avcC_length_size, i_sps, i_pps );
 256
 257         if( !p_sys->p_sps || p_sys->p_pps )
 258             return VLC_EGENERIC;
 259
 260         /* FIXME: FFMPEG isn't happy at all if you leave this */
 261         if( p_dec->fmt_out.i_extra > 0 ) free( p_dec->fmt_out.p_extra );
 262         p_dec->fmt_out.i_extra = 0;
 263         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 = 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,
 271                     p_sys->p_sps->p_buffer, p_sys->p_sps->i_buffer);
 272             memcpy( (uint8_t*)p_dec->fmt_out.p_extra+p_sys->p_sps->i_buffer,
 273                     p_sys->p_pps->p_buffer, p_sys->p_pps->i_buffer);
 274             p_sys->b_header = true;
 275         }
 276         else p_dec->fmt_out.i_extra = 0;
 277
 278         /* Set callback */
 279         p_dec->pf_packetize = PacketizeAVC1;
 280     }
 281     else
 282     {
 283         /* This type of stream contains data with 3 of 4 byte startcodes
 284          * The fmt_in.p_extra MAY contain SPS/PPS with 4 byte startcodes
 285          * The fmt_out.p_extra should be the same */
 286
 287         /* Set callback */
 288         p_dec->pf_packetize = Packetize;
 289
 290         /* */
 291         if( p_dec->fmt_in.i_extra > 0 )
 292         {
 293             block_t *p_init = block_New( p_dec, p_dec->fmt_in.i_extra );
 294             block_t *p_pic;
 295
 296             memcpy( p_init->p_buffer, p_dec->fmt_in.p_extra,
 297                     p_dec->fmt_in.i_extra );
 298
 299             while( ( p_pic = Packetize( p_dec, &p_init ) ) )
 300             {
 301                 /* Should not occur because we should only receive SPS/PPS */
 302                 block_Release( p_pic );
 303             }
 304         }
 305     }
 306
 307     return VLC_SUCCESS;
 308 }
 309
 310 /*****************************************************************************
 311  * Close: clean up the packetizer
 312  *****************************************************************************/
 313 static void Close( vlc_object_t *p_this )
 314 {
 315     decoder_t *p_dec = (decoder_t*)p_this;
 316     decoder_sys_t *p_sys = p_dec->p_sys;
 317
 318     if( p_sys->p_frame ) block_ChainRelease( p_sys->p_frame );
 319     if( p_sys->p_sps ) block_Release( p_sys->p_sps );
 320     if( p_sys->p_pps ) block_Release( p_sys->p_pps );
 321     block_BytestreamRelease( &p_sys->bytestream );
 322     free( p_sys );
 323 }
 324
 325 /****************************************************************************
 326  * Packetize: the whole thing
 327  * Search for the startcodes 3 or more bytes
 328  * Feed ParseNALBlock ALWAYS with 4 byte startcode prepended NALs
 329  ****************************************************************************/
 330 static block_t *Packetize( decoder_t *p_dec, block_t **pp_block )
 331 {
 332     decoder_sys_t *p_sys = p_dec->p_sys;
 333     block_t       *p_pic;
 334
 335     if( !pp_block || !*pp_block )
 336         return NULL;
 337
 338     if( (*pp_block)->i_flags&(BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED) )
 339     {
 340         if( (*pp_block)->i_flags&BLOCK_FLAG_CORRUPTED )
 341         {
 342             p_sys->i_state = STATE_NOSYNC;
 343             block_BytestreamFlush( &p_sys->bytestream );
 344
 345             if( p_sys->p_frame )
 346                 block_ChainRelease( p_sys->p_frame );
 347             p_sys->p_frame = NULL;
 348             p_sys->slice.i_frame_type = 0;
 349             p_sys->b_slice = false;
 350         }
 351         block_Release( *pp_block );
 352         return NULL;
 353     }
 354
 355     block_BytestreamPush( &p_sys->bytestream, *pp_block );
 356
 357     for( ;; )
 358     {
 359         switch( p_sys->i_state )
 360         {
 361             case STATE_NOSYNC:
 362                 /* Skip until 3 byte startcode 0 0 1 */
 363                 if( block_FindStartcodeFromOffset( &p_sys->bytestream,
 364                       &p_sys->i_offset, p_sys->startcode+1, 3 ) == VLC_SUCCESS)
 365                 {
 366                     p_sys->i_state = STATE_NEXT_SYNC;
 367                 }
 368
 369                 if( p_sys->i_offset )
 370                 {
 371                     /* skip the data */
 372                     block_SkipBytes( &p_sys->bytestream, p_sys->i_offset );
 373                     p_sys->i_offset = 0;
 374                     block_BytestreamFlush( &p_sys->bytestream );
 375                 }
 376
 377                 if( p_sys->i_state != STATE_NEXT_SYNC )
 378                 {
 379                     /* Need more data */
 380                     return NULL;
 381                 }
 382
 383                 p_sys->i_offset = 1; /* To find next startcode */
 384
 385             case STATE_NEXT_SYNC:
 386                 /* Find the next 3 byte startcode 0 0 1*/
 387                 if( block_FindStartcodeFromOffset( &p_sys->bytestream,
 388                       &p_sys->i_offset, p_sys->startcode+1, 3 ) != VLC_SUCCESS)
 389                 {
 390                     /* Need more data */
 391                     return NULL;
 392                 }
 393
 394                 /* Get the new fragment and set the pts/dts */
 395                 p_pic = block_New( p_dec, p_sys->i_offset +1 );
 396                 p_pic->i_pts = p_sys->bytestream.p_block->i_pts;
 397                 p_pic->i_dts = p_sys->bytestream.p_block->i_dts;
 398                 /* Force 4 byte startcode 0 0 0 1 */
 399                 p_pic->p_buffer[0] = 0;
 400
 401                 block_GetBytes( &p_sys->bytestream, &p_pic->p_buffer[1],
 402                                 p_pic->i_buffer-1 );
 403
 404                 /* Remove trailing 0 bytes */
 405                 while( p_pic->i_buffer && (!p_pic->p_buffer[p_pic->i_buffer-1] ) )
 406                     p_pic->i_buffer--;
 407                 p_sys->i_offset = 0;
 408
 409                 /* Parse the NAL */
 410                 if( !( p_pic = ParseNALBlock( p_dec, p_pic ) ) )
 411                 {
 412                     p_sys->i_state = STATE_NOSYNC;
 413                     break;
 414                 }
 415 #if 0
 416                 msg_Dbg( p_dec, "pts=%"PRId64" dts=%"PRId64,
 417                          p_pic->i_pts, p_pic->i_dts );
 418 #endif
 419
 420                 /* So p_block doesn't get re-added several times */
 421                 *pp_block = block_BytestreamPop( &p_sys->bytestream );
 422
 423                 p_sys->i_state = STATE_NOSYNC;
 424
 425                 return p_pic;
 426         }
 427     }
 428 }
 429
 430 /****************************************************************************
 431  * PacketizeAVC1: Takes VCL blocks of data and creates annexe B type NAL stream
 432  * Will always use 4 byte 0 0 0 1 startcodes
 433  * Will prepend a SPS and PPS before each keyframe
 434  ****************************************************************************/
 435 static block_t *PacketizeAVC1( decoder_t *p_dec, block_t **pp_block )
 436 {
 437     decoder_sys_t *p_sys = p_dec->p_sys;
 438     block_t       *p_block;
 439     block_t       *p_ret = NULL;
 440     uint8_t       *p;
 441
 442     if( !pp_block || !*pp_block )
 443         return NULL;
 444     if( (*pp_block)->i_flags&(BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED) )
 445     {
 446         block_Release( *pp_block );
 447         return NULL;
 448     }
 449
 450     p_block = *pp_block;
 451     *pp_block = NULL;
 452
 453     for( p = p_block->p_buffer; p < &p_block->p_buffer[p_block->i_buffer]; )
 454     {
 455         block_t *p_pic;
 456         int i_size = 0;
 457         int i;
 458
 459         for( i = 0; i < p_sys->i_avcC_length_size; i++ )
 460         {
 461             i_size = (i_size << 8) | (*p++);
 462         }
 463
 464         if( i_size <= 0 ||
 465             i_size > ( p_block->p_buffer + p_block->i_buffer - p ) )
 466         {
 467             msg_Err( p_dec, "Broken frame : size %d is too big", i_size );
 468             break;
 469         }
 470
 471         block_t *p_part = nal_get_annexeb( p_dec, p, i_size );
 472         if( !p_part )
 473             break;
 474         p_part->i_dts = p_block->i_dts;
 475         p_part->i_pts = p_block->i_pts;
 476
 477         /* Parse the NAL */
 478         if( ( p_pic = ParseNALBlock( p_dec, p_part ) ) )
 479         {
 480             block_ChainAppend( &p_ret, p_pic );
 481         }
 482         p += i_size;
 483     }
 484     block_Release( p_block );
 485
 486     return p_ret;
 487 }
 488
 489 static block_t *nal_get_annexeb( decoder_t *p_dec, uint8_t *p, int i_size )
 490 {
 491     block_t *p_nal;
 492
 493     p_nal = block_New( p_dec, 4 + i_size );
 494     if( !p_nal ) return NULL;
 495
 496     /* Add start code */
 497     p_nal->p_buffer[0] = 0x00;
 498     p_nal->p_buffer[1] = 0x00;
 499     p_nal->p_buffer[2] = 0x00;
 500     p_nal->p_buffer[3] = 0x01;
 501
 502     /* Copy nalu */
 503     memcpy( &p_nal->p_buffer[4], p, i_size );
 504
 505     VLC_UNUSED(p_dec);
 506     return p_nal;
 507 }
 508
 509 static void nal_get_decoded( uint8_t **pp_ret, int *pi_ret,
 510                              uint8_t *src, int i_src )
 511 {
 512     uint8_t *end = &src[i_src];
 513     uint8_t *dst = malloc( i_src );
 514
 515     *pp_ret = dst;
 516
 517     if( dst )
 518     {
 519         while( src < end )
 520         {
 521             if( src < end - 3 && src[0] == 0x00 && src[1] == 0x00 &&
 522                 src[2] == 0x03 )
 523             {
 524                 *dst++ = 0x00;
 525                 *dst++ = 0x00;
 526
 527                 src += 3;
 528                 continue;
 529             }
 530             *dst++ = *src++;
 531         }
 532     }
 533     *pi_ret = dst - *pp_ret;
 534 }
 535
 536 static inline int bs_read_ue( bs_t *s )
 537 {
 538     int i = 0;
 539
 540     while( bs_read1( s ) == 0 && s->p < s->p_end && i < 32 )
 541     {
 542         i++;
 543     }
 544     return( ( 1 << i) - 1 + bs_read( s, i ) );
 545 }
 546
 547 static inline int bs_read_se( bs_t *s )
 548 {
 549     int val = bs_read_ue( s );
 550
 551     return val&0x01 ? (val+1)/2 : -(val/2);
 552 }
 553
 554 /*****************************************************************************
 555  * ParseNALBlock: parses annexB type NALs
 556  * All p_frag blocks are required to start with 0 0 0 1 4-byte startcode
 557  *****************************************************************************/
 558 static block_t *OutputPicture( decoder_t *p_dec )
 559 {
 560     decoder_sys_t *p_sys = p_dec->p_sys;
 561     block_t *p_pic;
 562
 563     if( !p_sys->b_header && p_sys->slice.i_frame_type != BLOCK_FLAG_TYPE_I)
 564         return NULL;
 565
 566     if( p_sys->slice.i_frame_type == BLOCK_FLAG_TYPE_I && p_sys->p_sps && p_sys->p_pps )
 567     {
 568         block_t *p_sps = block_Duplicate( p_sys->p_sps );
 569         block_t *p_pps = block_Duplicate( p_sys->p_pps );
 570         p_sps->i_dts = p_sys->p_frame->i_dts;
 571         p_sps->i_pts = p_sys->p_frame->i_pts;
 572         block_ChainAppend( &p_sps, p_pps );
 573         block_ChainAppend( &p_sps, p_sys->p_frame );
 574         p_sys->b_header = true;
 575         p_pic = block_ChainGather( p_sps );
 576     }
 577     else
 578     {
 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 = false;
 587
 588     return p_pic;
 589 }
 590
 591 static block_t *ParseNALBlock( decoder_t *p_dec, block_t *p_frag )
 592 {
 593     decoder_sys_t *p_sys = p_dec->p_sys;
 594     block_t *p_pic = NULL;
 595
 596     const int i_nal_ref_idc = (p_frag->p_buffer[4] >> 5)&0x03;
 597     const int i_nal_type = p_frag->p_buffer[4]&0x1f;
 598
 599     if( p_sys->b_slice && ( !p_sys->b_sps || !p_sys->b_pps ) )
 600     {
 601         block_ChainRelease( p_sys->p_frame );
 602         msg_Warn( p_dec, "waiting for SPS/PPS" );
 603
 604         /* Reset context */
 605         p_sys->slice.i_frame_type = 0;
 606         p_sys->p_frame = NULL;
 607         p_sys->b_slice = false;
 608     }
 609
 610     if( ( !p_sys->b_sps || !p_sys->b_pps ) &&
 611         i_nal_type >= NAL_SLICE && i_nal_type <= NAL_SLICE_IDR )
 612     {
 613         p_sys->b_slice = true;
 614         /* Fragment will be discarded later on */
 615     }
 616     else if( i_nal_type >= NAL_SLICE && i_nal_type <= NAL_SLICE_IDR )
 617     {
 618         uint8_t *dec = NULL;
 619         int i_dec = 0, i_first_mb, i_slice_type;
 620         slice_t slice;
 621         bool b_pic;
 622         bs_t s;
 623
 624         /* do not convert the whole frame */
 625         nal_get_decoded( &dec, &i_dec, &p_frag->p_buffer[5],
 626                          __MIN( p_frag->i_buffer - 5, 60 ) );
 627         bs_init( &s, dec, i_dec );
 628
 629         /* first_mb_in_slice */
 630         i_first_mb = bs_read_ue( &s );
 631
 632         /* slice_type */
 633         switch( (i_slice_type = bs_read_ue( &s )) )
 634         {
 635         case 0: case 5:
 636             slice.i_frame_type = BLOCK_FLAG_TYPE_P;
 637             break;
 638         case 1: case 6:
 639             slice.i_frame_type = BLOCK_FLAG_TYPE_B;
 640             break;
 641         case 2: case 7:
 642             slice.i_frame_type = BLOCK_FLAG_TYPE_I;
 643             break;
 644         case 3: case 8: /* SP */
 645             slice.i_frame_type = BLOCK_FLAG_TYPE_P;
 646             break;
 647         case 4: case 9:
 648             slice.i_frame_type = BLOCK_FLAG_TYPE_I;
 649             break;
 650         default:
 651             slice.i_frame_type = 0;
 652             break;
 653         }
 654
 655         /* */
 656         slice.i_nal_type = i_nal_type;
 657         slice.i_nal_ref_idc = i_nal_ref_idc;
 658
 659         slice.i_pic_parameter_set_id = bs_read_ue( &s );
 660         slice.i_frame_num = bs_read( &s, p_sys->i_log2_max_frame_num + 4 );
 661
 662         slice.i_field_pic_flag = 0;
 663         slice.i_bottom_field_flag = -1;
 664         if( !p_sys->b_frame_mbs_only )
 665         {
 666             /* field_pic_flag */
 667             slice.i_field_pic_flag = bs_read( &s, 1 );
 668             if( slice.i_field_pic_flag )
 669                 slice.i_bottom_field_flag = bs_read( &s, 1 );
 670         }
 671
 672         slice.i_idr_pic_id = p_sys->slice.i_idr_pic_id;
 673         if( slice.i_nal_type == NAL_SLICE_IDR )
 674             slice.i_idr_pic_id = bs_read_ue( &s );
 675
 676         slice.i_pic_order_cnt_lsb = -1;
 677         slice.i_delta_pic_order_cnt_bottom = -1;
 678         slice.i_delta_pic_order_cnt0 = 0;
 679         slice.i_delta_pic_order_cnt1 = 0;
 680         if( p_sys->i_pic_order_cnt_type == 0 )
 681         {
 682             slice.i_pic_order_cnt_lsb = bs_read( &s, p_sys->i_log2_max_pic_order_cnt_lsb + 4 );
 683             if( p_sys->i_pic_order_present_flag && !slice.i_field_pic_flag )
 684                 slice.i_delta_pic_order_cnt_bottom = bs_read_se( &s );
 685         }
 686         else if( (p_sys->i_pic_order_cnt_type == 1) &&
 687                  (!p_sys->i_delta_pic_order_always_zero_flag) )
 688         {
 689             slice.i_delta_pic_order_cnt0 = bs_read_se( &s );
 690             if( p_sys->i_pic_order_present_flag && !slice.i_field_pic_flag )
 691                 slice.i_delta_pic_order_cnt1 = bs_read_se( &s );
 692         }
 693
 694         /* Detection of the first VCL NAL unit of a primary coded picture
 695          * (cf. 7.4.1.2.4) */
 696         b_pic = false;
 697         if( slice.i_frame_num != p_sys->slice.i_frame_num ||
 698             slice.i_pic_parameter_set_id != p_sys->slice.i_pic_parameter_set_id ||
 699             slice.i_field_pic_flag != p_sys->slice.i_field_pic_flag ||
 700             slice.i_nal_ref_idc != p_sys->slice.i_nal_ref_idc )
 701             b_pic = true;
 702         if( (slice.i_bottom_field_flag != -1) &&
 703             (p_sys->slice.i_bottom_field_flag != -1) &&
 704             (slice.i_bottom_field_flag != p_sys->slice.i_bottom_field_flag) )
 705             b_pic = true;
 706         if( p_sys->i_pic_order_cnt_type == 0 &&
 707             ( slice.i_pic_order_cnt_lsb != p_sys->slice.i_pic_order_cnt_lsb ||
 708               slice.i_delta_pic_order_cnt_bottom != p_sys->slice.i_delta_pic_order_cnt_bottom ) )
 709             b_pic = true;
 710         else if( p_sys->i_pic_order_cnt_type == 1 &&
 711                  ( slice.i_delta_pic_order_cnt0 != p_sys->slice.i_delta_pic_order_cnt0 ||
 712                    slice.i_delta_pic_order_cnt1 != p_sys->slice.i_delta_pic_order_cnt1 ) )
 713             b_pic = true;
 714         if( ( slice.i_nal_type == NAL_SLICE_IDR || p_sys->slice.i_nal_type == NAL_SLICE_IDR ) &&
 715             ( slice.i_nal_type != p_sys->slice.i_nal_type || slice.i_idr_pic_id != p_sys->slice.i_idr_pic_id ) )
 716                 b_pic = true;
 717
 718         /* */
 719         p_sys->slice = slice;
 720
 721         if( b_pic && p_sys->b_slice )
 722             p_pic = OutputPicture( p_dec );
 723
 724         p_sys->b_slice = true;
 725
 726         free( dec );
 727     }
 728     else if( i_nal_type == NAL_SPS )
 729     {
 730         uint8_t *dec = NULL;
 731         int     i_dec = 0;
 732         bs_t s;
 733         int i_tmp;
 734
 735         if( p_sys->b_slice )
 736             p_pic = OutputPicture( p_dec );
 737
 738         if( !p_sys->b_sps ) msg_Dbg( p_dec, "found NAL_SPS" );
 739
 740         p_sys->b_sps = true;
 741
 742         nal_get_decoded( &dec, &i_dec, &p_frag->p_buffer[5],
 743                          p_frag->i_buffer - 5 );
 744
 745         bs_init( &s, dec, i_dec );
 746         /* Skip profile(8), constraint_set012, reserver(5), level(8) */
 747         bs_skip( &s, 8 + 1+1+1 + 5 + 8 );
 748         /* sps id */
 749         bs_read_ue( &s );
 750         /* Skip i_log2_max_frame_num */
 751         p_sys->i_log2_max_frame_num = bs_read_ue( &s );
 752         if( p_sys->i_log2_max_frame_num > 12)
 753             p_sys->i_log2_max_frame_num = 12;
 754         /* Read poc_type */
 755         p_sys->i_pic_order_cnt_type = bs_read_ue( &s );
 756         if( p_sys->i_pic_order_cnt_type == 0 )
 757         {
 758             /* skip i_log2_max_poc_lsb */
 759             p_sys->i_log2_max_pic_order_cnt_lsb = bs_read_ue( &s );
 760             if( p_sys->i_log2_max_pic_order_cnt_lsb > 12 )
 761                 p_sys->i_log2_max_pic_order_cnt_lsb = 12;
 762         }
 763         else if( p_sys->i_pic_order_cnt_type == 1 )
 764         {
 765             int i_cycle;
 766             /* skip b_delta_pic_order_always_zero */
 767             p_sys->i_delta_pic_order_always_zero_flag = bs_read( &s, 1 );
 768             /* skip i_offset_for_non_ref_pic */
 769             bs_read_se( &s );
 770             /* skip i_offset_for_top_to_bottom_field */
 771             bs_read_se( &s );
 772             /* read i_num_ref_frames_in_poc_cycle */
 773             i_cycle = bs_read_ue( &s );
 774             if( i_cycle > 256 ) i_cycle = 256;
 775             while( i_cycle > 0 )
 776             {
 777                 /* skip i_offset_for_ref_frame */
 778                 bs_read_se(&s );
 779             }
 780         }
 781         /* i_num_ref_frames */
 782         bs_read_ue( &s );
 783         /* b_gaps_in_frame_num_value_allowed */
 784         bs_skip( &s, 1 );
 785
 786         /* Read size */
 787         p_dec->fmt_out.video.i_width  = 16 * ( bs_read_ue( &s ) + 1 );
 788         p_dec->fmt_out.video.i_height = 16 * ( bs_read_ue( &s ) + 1 );
 789
 790         /* b_frame_mbs_only */
 791         p_sys->b_frame_mbs_only = bs_read( &s, 1 );
 792         if( p_sys->b_frame_mbs_only == 0 )
 793         {
 794             bs_skip( &s, 1 );
 795         }
 796         /* b_direct8x8_inference */
 797         bs_skip( &s, 1 );
 798
 799         /* crop */
 800         i_tmp = bs_read( &s, 1 );
 801         if( i_tmp )
 802         {
 803             /* left */
 804             bs_read_ue( &s );
 805             /* right */
 806             bs_read_ue( &s );
 807             /* top */
 808             bs_read_ue( &s );
 809             /* bottom */
 810             bs_read_ue( &s );
 811         }
 812
 813         /* vui */
 814         i_tmp = bs_read( &s, 1 );
 815         if( i_tmp )
 816         {
 817             /* read the aspect ratio part if any FIXME check it */
 818             i_tmp = bs_read( &s, 1 );
 819             if( i_tmp )
 820             {
 821                 static const struct { int w, h; } sar[14] =
 822                 {
 823                     { 0,   0 }, { 1,   1 }, { 12, 11 }, { 10, 11 },
 824                     { 16, 11 }, { 40, 33 }, { 24, 11 }, { 20, 11 },
 825                     { 32, 11 }, { 80, 33 }, { 18, 11 }, { 15, 11 },
 826                     { 64, 33 }, { 160,99 },
 827                 };
 828                 int i_sar = bs_read( &s, 8 );
 829                 int w, h;
 830
 831                 if( i_sar < 14 )
 832                 {
 833                     w = sar[i_sar].w;
 834                     h = sar[i_sar].h;
 835                 }
 836                 else
 837                 {
 838                     w = bs_read( &s, 16 );
 839                     h = bs_read( &s, 16 );
 840                 }
 841                 if( h != 0 )
 842                     p_dec->fmt_out.video.i_aspect = VOUT_ASPECT_FACTOR * w /
 843                         h * p_dec->fmt_out.video.i_width /
 844                         p_dec->fmt_out.video.i_height;
 845                 else
 846                     p_dec->fmt_out.video.i_aspect = VOUT_ASPECT_FACTOR;
 847             }
 848         }
 849
 850         free( dec );
 851
 852         /* We have a new SPS */
 853         if( p_sys->p_sps ) block_Release( p_sys->p_sps );
 854         p_sys->p_sps = p_frag;
 855
 856         /* Do not append the SPS because we will insert it on keyframes */
 857         return p_pic;
 858     }
 859     else if( i_nal_type == NAL_PPS )
 860     {
 861         bs_t s;
 862
 863         if( p_sys->b_slice )
 864             p_pic = OutputPicture( p_dec );
 865
 866         bs_init( &s, &p_frag->p_buffer[5], p_frag->i_buffer - 5 );
 867         bs_read_ue( &s ); // pps id
 868         bs_read_ue( &s ); // sps id
 869         bs_skip( &s, 1 ); // entropy coding mode flag
 870         p_sys->i_pic_order_present_flag = bs_read( &s, 1 );
 871
 872         if( !p_sys->b_pps ) msg_Dbg( p_dec, "found NAL_PPS" );
 873         p_sys->b_pps = true;
 874
 875         /* TODO */
 876
 877         /* We have a new PPS */
 878         if( p_sys->p_pps ) block_Release( p_sys->p_pps );
 879         p_sys->p_pps = p_frag;
 880
 881         /* Do not append the PPS because we will insert it on keyframes */
 882         return p_pic;
 883     }
 884     else if( i_nal_type == NAL_AU_DELIMITER ||
 885              i_nal_type == NAL_SEI ||
 886              ( i_nal_type >= 13 && i_nal_type <= 18 ) )
 887     {
 888         if( p_sys->b_slice )
 889             p_pic = OutputPicture( p_dec );
 890     }
 891
 892     /* Append the block */
 893     block_ChainAppend( &p_sys->p_frame, p_frag );
 894
 895     return p_pic;
 896 }