git.sesse.net Git - vlc/blob - modules/packetizer/h264.c

   1 /*****************************************************************************
   2  * h264.c: h264/avc video packetizer
   3  *****************************************************************************
   4  * Copyright (C) 2001, 2002 VideoLAN
   5  * $Id$
   6  *
   7  * Authors: Laurent Aimar <fenrir@via.ecp.fr>
   8  *          Eric Petit <titer@videolan.org>
   9  *          Gildas Bazin <gbazin@netcourrier.com>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
  24  *****************************************************************************/
  25
  26 /*****************************************************************************
  27  * Preamble
  28  *****************************************************************************/
  29 #include <stdlib.h>                                      /* malloc(), free() */
  30
  31 #include <vlc/vlc.h>
  32 #include <vlc/decoder.h>
  33 #include <vlc/sout.h>
  34
  35 #include "vlc_block_helper.h"
  36 #include "vlc_bits.h"
  37
  38 /*****************************************************************************
  39  * Module descriptor
  40  *****************************************************************************/
  41 static int  Open ( vlc_object_t * );
  42 static void Close( vlc_object_t * );
  43
  44 vlc_module_begin();
  45     set_description( _("H264 video packetizer") );
  46     set_capability( "packetizer", 50 );
  47     set_callbacks( Open, Close );
  48 vlc_module_end();
  49
  50
  51 /****************************************************************************
  52  * Local prototypes
  53  ****************************************************************************/
  54 static block_t *Packetize( decoder_t *, block_t ** );
  55 static block_t *PacketizeAVC1( decoder_t *, block_t ** );
  56
  57 struct decoder_sys_t
  58 {
  59     block_bytestream_t bytestream;
  60
  61     int     i_state;
  62     int     i_offset;
  63     uint8_t startcode[4];
  64
  65     vlc_bool_t b_slice;
  66     block_t    *p_frame;
  67
  68     int64_t      i_dts;
  69     int64_t      i_pts;
  70     unsigned int i_flags;
  71
  72     vlc_bool_t   b_sps;
  73
  74     /* avcC data */
  75     int i_avcC_length_size;
  76 };
  77
  78 enum
  79 {
  80     STATE_NOSYNC,
  81     STATE_NEXT_SYNC,
  82 };
  83
  84 enum nal_unit_type_e
  85 {
  86     NAL_UNKNOWN = 0,
  87     NAL_SLICE   = 1,
  88     NAL_SLICE_DPA   = 2,
  89     NAL_SLICE_DPB   = 3,
  90     NAL_SLICE_DPC   = 4,
  91     NAL_SLICE_IDR   = 5,    /* ref_idc != 0 */
  92     NAL_SEI         = 6,    /* ref_idc == 0 */
  93     NAL_SPS         = 7,
  94     NAL_PPS         = 8
  95     /* ref_idc == 0 for 6,9,10,11,12 */
  96 };
  97
  98 enum nal_priority_e
  99 {
 100     NAL_PRIORITY_DISPOSABLE = 0,
 101     NAL_PRIORITY_LOW        = 1,
 102     NAL_PRIORITY_HIGH       = 2,
 103     NAL_PRIORITY_HIGHEST    = 3,
 104 };
 105
 106 static block_t *ParseNALBlock( decoder_t *, block_t * );
 107
 108 static block_t *nal_get_encoded( decoder_t *, uint8_t *p, int );
 109
 110 /*****************************************************************************
 111  * Open: probe the packetizer and return score
 112  *****************************************************************************/
 113 static int Open( vlc_object_t *p_this )
 114 {
 115     decoder_t     *p_dec = (decoder_t*)p_this;
 116     decoder_sys_t *p_sys;
 117
 118     if( p_dec->fmt_in.i_codec != VLC_FOURCC( 'h', '2', '6', '4') &&
 119         p_dec->fmt_in.i_codec != VLC_FOURCC( 'H', '2', '6', '4') &&
 120         ( p_dec->fmt_in.i_codec != VLC_FOURCC( 'a', 'v', 'c', '1') || p_dec->fmt_in.i_extra < 7 ) )
 121     {
 122         return VLC_EGENERIC;
 123     }
 124
 125     /* Allocate the memory needed to store the decoder's structure */
 126     if( ( p_dec->p_sys = p_sys = malloc( sizeof(decoder_sys_t) ) ) == NULL )
 127     {
 128         msg_Err( p_dec, "out of memory" );
 129         return VLC_EGENERIC;
 130     }
 131     p_sys->i_state = STATE_NOSYNC;
 132     p_sys->i_offset = 0;
 133     p_sys->startcode[0] = 0;
 134     p_sys->startcode[1] = 0;
 135     p_sys->startcode[2] = 0;
 136     p_sys->startcode[3] = 1;
 137     p_sys->bytestream = block_BytestreamInit( p_dec );
 138     p_sys->b_slice = VLC_FALSE;
 139     p_sys->p_frame = NULL;
 140     p_sys->i_dts   = 0;
 141     p_sys->i_pts   = 0;
 142     p_sys->i_flags = 0;
 143     p_sys->b_sps   = VLC_FALSE;
 144
 145     /* Setup properties */
 146     es_format_Copy( &p_dec->fmt_out, &p_dec->fmt_in );
 147     p_dec->fmt_out.i_codec = VLC_FOURCC( 'h', '2', '6', '4' );
 148
 149     if( p_dec->fmt_in.i_codec == VLC_FOURCC( 'a', 'v', 'c', '1' ) )
 150     {
 151         uint8_t *p = &((uint8_t*)p_dec->fmt_in.p_extra)[4];
 152         int i_sps, i_pps;
 153         int i;
 154
 155         /* Parse avcC */
 156         p_sys->i_avcC_length_size = 1 + ((*p++)&0x03);
 157
 158         /* Read SPS */
 159         i_sps = (*p++)&0x1f;
 160
 161         for( i = 0; i < i_sps; i++ )
 162         {
 163             int i_length = GetWBE( p );
 164             block_t *p_sps = nal_get_encoded( p_dec, p+2, i_length );
 165
 166             ParseNALBlock( p_dec, p_sps );
 167             p += 2 + i_length;
 168         }
 169         /* Read PPS */
 170         i_pps = *p++;
 171         for( i = 0; i < i_pps; i++ )
 172         {
 173             int i_length = GetWBE( p );
 174             block_t *p_pps = nal_get_encoded( p_dec, p+2, i_length );
 175
 176             ParseNALBlock( p_dec, p_pps );
 177             p += 2 + i_length;
 178         }
 179         msg_Dbg( p_dec, "avcC length size=%d sps=%d pps=%d",
 180                  p_sys->i_avcC_length_size, i_sps, i_pps );
 181
 182         /* Set callback */
 183         p_dec->pf_packetize = PacketizeAVC1;
 184     }
 185     else
 186     {
 187         /* Set callback */
 188         p_dec->pf_packetize = Packetize;
 189     }
 190
 191     return VLC_SUCCESS;
 192 }
 193
 194 /*****************************************************************************
 195  * Close: clean up the packetizer
 196  *****************************************************************************/
 197 static void Close( vlc_object_t *p_this )
 198 {
 199     decoder_t *p_dec = (decoder_t*)p_this;
 200     decoder_sys_t *p_sys = p_dec->p_sys;
 201
 202     block_BytestreamRelease( &p_sys->bytestream );
 203     free( p_sys );
 204 }
 205
 206 /****************************************************************************
 207  * Packetize: the whole thing
 208  ****************************************************************************/
 209 static block_t *Packetize( decoder_t *p_dec, block_t **pp_block )
 210 {
 211     decoder_sys_t *p_sys = p_dec->p_sys;
 212     block_t       *p_pic;
 213
 214     if( !pp_block || !*pp_block ) return NULL;
 215
 216     block_BytestreamPush( &p_sys->bytestream, *pp_block );
 217
 218     for( ;; )
 219     {
 220         switch( p_sys->i_state )
 221         {
 222             case STATE_NOSYNC:
 223                 if( block_FindStartcodeFromOffset( &p_sys->bytestream,
 224                         &p_sys->i_offset, p_sys->startcode, 4 ) == VLC_SUCCESS )
 225                 {
 226                     p_sys->i_state = STATE_NEXT_SYNC;
 227                 }
 228
 229                 if( p_sys->i_offset )
 230                 {
 231                     block_SkipBytes( &p_sys->bytestream, p_sys->i_offset );
 232                     p_sys->i_offset = 0;
 233                     block_BytestreamFlush( &p_sys->bytestream );
 234                 }
 235
 236                 if( p_sys->i_state != STATE_NEXT_SYNC )
 237                 {
 238                     /* Need more data */
 239                     return NULL;
 240                 }
 241
 242                 p_sys->i_offset = 1; /* To find next startcode */
 243
 244             case STATE_NEXT_SYNC:
 245                 /* Find the next startcode */
 246                 if( block_FindStartcodeFromOffset( &p_sys->bytestream,
 247                         &p_sys->i_offset, p_sys->startcode, 4 ) != VLC_SUCCESS )
 248                 {
 249                     /* Need more data */
 250                     return NULL;
 251                 }
 252
 253                 /* Get the new fragment and set the pts/dts */
 254                 p_pic = block_New( p_dec, p_sys->i_offset );
 255                 p_pic->i_pts = p_sys->bytestream.p_block->i_pts;
 256                 p_pic->i_dts = p_sys->bytestream.p_block->i_dts;
 257
 258                 block_GetBytes( &p_sys->bytestream, p_pic->p_buffer,
 259                                 p_pic->i_buffer );
 260
 261                 p_sys->i_offset = 0;
 262
 263                 /* Parse the NAL */
 264                 if( !( p_pic = ParseNALBlock( p_dec, p_pic ) ) )
 265                 {
 266                     p_sys->i_state = STATE_NOSYNC;
 267                     break;
 268                 }
 269
 270                 /* So p_block doesn't get re-added several times */
 271                 *pp_block = block_BytestreamPop( &p_sys->bytestream );
 272
 273                 p_sys->i_state = STATE_NOSYNC;
 274
 275                 return p_pic;
 276         }
 277     }
 278 }
 279
 280 /****************************************************************************
 281  * PacketizeAVC1: the whole thing
 282  ****************************************************************************/
 283 static block_t *PacketizeAVC1( decoder_t *p_dec, block_t **pp_block )
 284 {
 285     decoder_sys_t *p_sys = p_dec->p_sys;
 286     block_t       *p_block;
 287     block_t       *p_ret = NULL;
 288     uint8_t       *p;
 289
 290     if( !pp_block || !*pp_block ) return NULL;
 291
 292     p_block = *pp_block;
 293     *pp_block = NULL;
 294
 295     for( p = p_block->p_buffer; p < &p_block->p_buffer[p_block->i_buffer]; )
 296     {
 297         block_t *p_pic;
 298         int i_size = 0;
 299         int i;
 300
 301         for( i = 0; i < p_sys->i_avcC_length_size; i++ )
 302         {
 303             i_size = (i_size << 8) | (*p++);
 304         }
 305
 306         if( i_size > 0 )
 307         {
 308             block_t *p_part = nal_get_encoded( p_dec, p, i_size );
 309
 310             p_part->i_dts = p_block->i_dts;
 311             p_part->i_pts = p_block->i_pts;
 312             /* Parse the NAL */
 313             if( ( p_pic = ParseNALBlock( p_dec, p_part ) ) )
 314             {
 315                 block_ChainAppend( &p_ret, p_pic );
 316             }
 317         }
 318         p += i_size;
 319     }
 320
 321     return p_ret;
 322 }
 323
 324 static block_t *nal_get_encoded( decoder_t *p_dec, uint8_t *p, int i_size )
 325 {
 326     block_t *p_nal;
 327     int     i_nal_size = 5;
 328     uint8_t *src = &p[1];
 329     uint8_t *end = &p[i_size];
 330     uint8_t *dst;
 331     int     i_count = 0;
 332
 333     /* 1: compute real size */
 334     while( src < end )
 335     {
 336         if( i_count == 2 && *src <= 0x03 )
 337         {
 338             i_nal_size++;
 339             i_count = 0;
 340         }
 341         if( *src == 0 )
 342         {
 343             i_count++;
 344         }
 345         else
 346         {
 347             i_count = 0;
 348         }
 349         i_nal_size++;
 350         src++;
 351     }
 352
 353     /* 2: encode it */
 354     p_nal = block_New( p_dec, i_nal_size );
 355     i_count = 0;
 356     src = p;
 357     dst = p_nal->p_buffer;
 358
 359     /* add start code */
 360     *dst++ = 0x00;
 361     *dst++ = 0x00;
 362     *dst++ = 0x00;
 363     *dst++ = 0x01;
 364
 365     /* nal type */
 366     *dst++ = *src++;
 367
 368     while( src < end )
 369     {
 370         if( i_count == 2 && *src <= 0x03 )
 371         {
 372             *dst++ = 0x03;
 373             i_count = 0;
 374         }
 375         if( *src == 0 )
 376         {
 377             i_count++;
 378         }
 379         else
 380         {
 381             i_count = 0;
 382         }
 383         *dst++ = *src++;
 384     }
 385
 386     return p_nal;
 387 }
 388
 389 static void nal_get_decoded( uint8_t **pp_ret, int *pi_ret, uint8_t *src, int i_src )
 390 {
 391     uint8_t *end = &src[i_src];
 392     uint8_t *dst = malloc( i_src );
 393
 394     *pp_ret = dst;
 395
 396     while( src < end )
 397     {
 398         if( src < end - 3 && src[0] == 0x00 && src[1] == 0x00  && src[2] == 0x03 )
 399         {
 400             *dst++ = 0x00;
 401             *dst++ = 0x00;
 402
 403             src += 3;
 404             continue;
 405         }
 406         *dst++ = *src++;
 407     }
 408
 409     *pi_ret = dst - *pp_ret;
 410 }
 411
 412 static inline int bs_read_ue( bs_t *s )
 413 {
 414     int i = 0;
 415
 416     while( bs_read1( s ) == 0 && s->p < s->p_end && i < 32 )
 417     {
 418         i++;
 419     }
 420     return( ( 1 << i) - 1 + bs_read( s, i ) );
 421 }
 422 static inline int bs_read_se( bs_t *s )
 423 {
 424     int val = bs_read_ue( s );
 425
 426     return val&0x01 ? (val+1)/2 : -(val/2);
 427 }
 428
 429
 430 static block_t *ParseNALBlock( decoder_t *p_dec, block_t *p_frag )
 431 {
 432     decoder_sys_t *p_sys = p_dec->p_sys;
 433     block_t *p_pic = NULL;
 434
 435     const int i_ref_idc = (p_frag->p_buffer[4] >> 5)&0x03;
 436     const int i_nal_type= p_frag->p_buffer[4]&0x1f;
 437
 438     if( p_sys->b_slice &&
 439         ( i_nal_type == NAL_SLICE || i_nal_type == NAL_SLICE_IDR ||
 440           i_nal_type == NAL_SLICE_DPC || i_nal_type == NAL_SPS || i_nal_type == NAL_PPS ) )
 441     {
 442         if( p_sys->b_sps )
 443         {
 444             p_pic = block_ChainGather( p_sys->p_frame );
 445             p_pic->i_dts = p_sys->i_dts;
 446             p_pic->i_pts = p_sys->i_pts;
 447             p_pic->i_length = 0;    /* FIXME */
 448             p_pic->i_flags = p_sys->i_flags;
 449         }
 450         else
 451         {
 452             block_ChainRelease( p_sys->p_frame );
 453             msg_Warn( p_dec, "waiting SPS" );
 454         }
 455
 456         /* reset context */
 457         p_sys->p_frame = NULL;
 458         p_sys->b_slice = VLC_FALSE;
 459         //p_sys->i_dts += 40000;
 460     }
 461
 462     if( i_nal_type >= NAL_SLICE && i_nal_type <= NAL_SLICE_IDR )
 463     {
 464         uint8_t *dec;
 465         int     i_dec;
 466         bs_t s;
 467
 468         p_sys->b_slice = VLC_TRUE;
 469         p_sys->i_dts   = p_frag->i_dts;
 470         p_sys->i_pts   = p_frag->i_pts;
 471
 472         /* do not convert the whole frame */
 473         nal_get_decoded( &dec, &i_dec, &p_frag->p_buffer[5], __MIN( p_frag->i_buffer - 5, 60 ) );
 474         bs_init( &s, dec, i_dec );
 475
 476         /* i_first_mb */
 477         bs_read_ue( &s );
 478         /* picture type */
 479         switch( bs_read_ue( &s ) )
 480         {
 481             case 0: case 5:
 482                 p_sys->i_flags = BLOCK_FLAG_TYPE_P;
 483                 break;
 484             case 1: case 6:
 485                 p_sys->i_flags =BLOCK_FLAG_TYPE_B;
 486                 break;
 487             case 2: case 7:
 488                 p_sys->i_flags = BLOCK_FLAG_TYPE_I;
 489                 break;
 490             case 3: case 8: /* SP */
 491                 p_sys->i_flags = BLOCK_FLAG_TYPE_P;
 492                 break;
 493             case 4: case 9:
 494                 p_sys->i_flags = BLOCK_FLAG_TYPE_I;
 495                 break;
 496         }
 497
 498         free( dec );
 499     }
 500     else if( i_nal_type == NAL_SPS )
 501     {
 502         uint8_t *dec;
 503         int     i_dec;
 504         bs_t s;
 505         int i_tmp;
 506
 507         p_sys->b_sps = VLC_TRUE;
 508
 509         nal_get_decoded( &dec, &i_dec, &p_frag->p_buffer[5], p_frag->i_buffer - 5 );
 510
 511         bs_init( &s, dec, i_dec );
 512         /* Skip profile(8), constraint_set012, reserver(5), level(8) */
 513         bs_skip( &s, 8 + 1+1+1 + 5 + 8 );
 514         /* sps id */
 515         bs_read_ue( &s );
 516         /* Skip i_log2_max_frame_num */
 517         bs_read_ue( &s );
 518         /* Read poc_type */
 519         i_tmp = bs_read_ue( &s );
 520         if( i_tmp == 0 )
 521         {
 522             /* skip i_log2_max_poc_lsb */
 523             bs_read_ue( &s );
 524         }
 525         else if( i_tmp == 1 )
 526         {
 527             int i_cycle;
 528             /* skip b_delta_pic_order_always_zero */
 529             bs_skip( &s, 1 );
 530             /* skip i_offset_for_non_ref_pic */
 531             bs_read_se( &s );
 532             /* skip i_offset_for_top_to_bottom_field */
 533             bs_read_se( &s );
 534             /* read i_num_ref_frames_in_poc_cycle */
 535             i_cycle = bs_read_ue( &s );
 536             if( i_cycle > 256 ) i_cycle = 256;
 537             while( i_cycle > 0 )
 538             {
 539                 /* skip i_offset_for_ref_frame */
 540                 bs_read_se(&s );
 541             }
 542         }
 543         /* i_num_ref_frames */
 544         bs_read_ue( &s );
 545         /* b_gaps_in_frame_num_value_allowed */
 546         bs_skip( &s, 1 );
 547
 548         /* Read size */
 549         p_dec->fmt_out.video.i_width  = 16 * ( bs_read_ue( &s ) + 1 );
 550         p_dec->fmt_out.video.i_height = 16 * ( bs_read_ue( &s ) + 1 );
 551
 552         /* b_frame_mbs_only */
 553         i_tmp = bs_read( &s, 1 );
 554         if( i_tmp == 0 )
 555         {
 556             bs_skip( &s, 1 );
 557         }
 558         /* b_direct8x8_inference */
 559         bs_skip( &s, 1 );
 560
 561         /* crop ? */
 562         i_tmp = bs_read( &s, 1 );
 563         if( i_tmp )
 564         {
 565             /* left */
 566             p_dec->fmt_out.video.i_width -= 2 * bs_read_ue( &s );
 567             /* right */
 568             p_dec->fmt_out.video.i_width -= 2 * bs_read_ue( &s );
 569             /* top */
 570             p_dec->fmt_out.video.i_height -= 2 * bs_read_ue( &s );
 571             /* bottom */
 572             p_dec->fmt_out.video.i_height -= 2 * bs_read_ue( &s );
 573         }
 574
 575         /* vui */
 576         i_tmp = bs_read( &s, 1 );
 577         if( i_tmp )
 578         {
 579             /* read the aspect ratio part if any FIXME check it */
 580             i_tmp = bs_read( &s, 1 );
 581             if( i_tmp )
 582             {
 583                 static const struct { int w, h; } sar[14] =
 584                 {
 585                     { 0,   0 }, { 1,   1 }, { 12, 11 }, { 10, 11 },
 586                     { 16, 11 }, { 40, 33 }, { 24, 11 }, { 20, 11 },
 587                     { 32, 11 }, { 80, 33 }, { 18, 11 }, { 15, 11 },
 588                     { 64, 33 }, { 160,99 },
 589                 };
 590                 int i_sar = bs_read( &s, 8 );
 591                 int w, h;
 592
 593                 if( i_sar < 14 )
 594                 {
 595                     w = sar[i_sar].w;
 596                     h = sar[i_sar].h;
 597                 }
 598                 else
 599                 {
 600                     w = bs_read( &s, 16 );
 601                     h = bs_read( &s, 16 );
 602                 }
 603                 p_dec->fmt_out.video.i_aspect =
 604                     VOUT_ASPECT_FACTOR *
 605                     w / h *
 606                     p_dec->fmt_out.video.i_width / p_dec->fmt_out.video.i_height;
 607             }
 608         }
 609
 610         free( dec );
 611     }
 612     else if( i_nal_type == NAL_PPS )
 613     {
 614         bs_t s;
 615         bs_init( &s, &p_frag->p_buffer[5], p_frag->i_buffer - 5 );
 616
 617         /* TODO */
 618     }
 619
 620
 621     /* Append the block */
 622     block_ChainAppend( &p_sys->p_frame, p_frag );
 623
 624     return p_pic;
 625 }
 626