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@videolan.org>
  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     /* Useful values of the Sequence Parameter Set */
  78     int i_log2_max_frame_num;
  79     int b_frame_mbs_only;
  80
  81     /* Useful values of the Slice Header */
  82     int i_nal_type;
  83     int i_idr_pic_id;
  84     int i_frame_num;
  85 };
  86
  87 enum
  88 {
  89     STATE_NOSYNC,
  90     STATE_NEXT_SYNC,
  91 };
  92
  93 enum nal_unit_type_e
  94 {
  95     NAL_UNKNOWN = 0,
  96     NAL_SLICE   = 1,
  97     NAL_SLICE_DPA   = 2,
  98     NAL_SLICE_DPB   = 3,
  99     NAL_SLICE_DPC   = 4,
 100     NAL_SLICE_IDR   = 5,    /* ref_idc != 0 */
 101     NAL_SEI         = 6,    /* ref_idc == 0 */
 102     NAL_SPS         = 7,
 103     NAL_PPS         = 8
 104     /* ref_idc == 0 for 6,9,10,11,12 */
 105 };
 106
 107 enum nal_priority_e
 108 {
 109     NAL_PRIORITY_DISPOSABLE = 0,
 110     NAL_PRIORITY_LOW        = 1,
 111     NAL_PRIORITY_HIGH       = 2,
 112     NAL_PRIORITY_HIGHEST    = 3,
 113 };
 114
 115 static block_t *ParseNALBlock( decoder_t *, block_t * );
 116
 117 static block_t *nal_get_annexeb( decoder_t *, uint8_t *p, int );
 118
 119 /*****************************************************************************
 120  * Open: probe the packetizer and return score
 121  *****************************************************************************/
 122 static int Open( vlc_object_t *p_this )
 123 {
 124     decoder_t     *p_dec = (decoder_t*)p_this;
 125     decoder_sys_t *p_sys;
 126
 127     if( p_dec->fmt_in.i_codec != VLC_FOURCC( 'h', '2', '6', '4') &&
 128         p_dec->fmt_in.i_codec != VLC_FOURCC( 'H', '2', '6', '4') &&
 129         p_dec->fmt_in.i_codec != VLC_FOURCC( 'V', 'S', 'S', 'H') &&
 130         p_dec->fmt_in.i_codec != VLC_FOURCC( 'v', 's', 's', 'h') &&
 131         ( p_dec->fmt_in.i_codec != VLC_FOURCC( 'a', 'v', 'c', '1') ||
 132           p_dec->fmt_in.i_extra < 7 ) )
 133     {
 134         return VLC_EGENERIC;
 135     }
 136
 137     /* Allocate the memory needed to store the decoder's structure */
 138     if( ( p_dec->p_sys = p_sys = malloc( sizeof(decoder_sys_t) ) ) == NULL )
 139     {
 140         msg_Err( p_dec, "out of memory" );
 141         return VLC_EGENERIC;
 142     }
 143     p_sys->i_state = STATE_NOSYNC;
 144     p_sys->i_offset = 0;
 145     p_sys->startcode[0] = 0;
 146     p_sys->startcode[1] = 0;
 147     p_sys->startcode[2] = 0;
 148     p_sys->startcode[3] = 1;
 149     p_sys->bytestream = block_BytestreamInit( p_dec );
 150     p_sys->b_slice = VLC_FALSE;
 151     p_sys->p_frame = NULL;
 152     p_sys->i_dts   = 0;
 153     p_sys->i_pts   = 0;
 154     p_sys->i_flags = 0;
 155     p_sys->b_sps   = VLC_FALSE;
 156
 157     p_sys->i_nal_type = -1;
 158     p_sys->i_idr_pic_id = -1;
 159     p_sys->i_frame_num = -1;
 160
 161     /* Setup properties */
 162     es_format_Copy( &p_dec->fmt_out, &p_dec->fmt_in );
 163     p_dec->fmt_out.i_codec = VLC_FOURCC( 'h', '2', '6', '4' );
 164
 165     if( p_dec->fmt_in.i_codec == VLC_FOURCC( 'a', 'v', 'c', '1' ) )
 166     {
 167         uint8_t *p = &((uint8_t*)p_dec->fmt_in.p_extra)[4];
 168         int i_sps, i_pps;
 169         int i;
 170
 171         /* Parse avcC */
 172         p_sys->i_avcC_length_size = 1 + ((*p++)&0x03);
 173
 174         /* Read SPS */
 175         i_sps = (*p++)&0x1f;
 176
 177         for( i = 0; i < i_sps; i++ )
 178         {
 179             int i_length = GetWBE( p );
 180             block_t *p_sps = nal_get_annexeb( p_dec, p+2, i_length );
 181
 182             ParseNALBlock( p_dec, p_sps );
 183             p += 2 + i_length;
 184         }
 185         /* Read PPS */
 186         i_pps = *p++;
 187         for( i = 0; i < i_pps; i++ )
 188         {
 189             int i_length = GetWBE( p );
 190             block_t *p_pps = nal_get_annexeb( p_dec, p+2, i_length );
 191
 192             ParseNALBlock( p_dec, p_pps );
 193             p += 2 + i_length;
 194         }
 195         msg_Dbg( p_dec, "avcC length size=%d sps=%d pps=%d",
 196                  p_sys->i_avcC_length_size, i_sps, i_pps );
 197
 198         /* Set callback */
 199         p_dec->pf_packetize = PacketizeAVC1;
 200     }
 201     else
 202     {
 203         /* Set callback */
 204         p_dec->pf_packetize = Packetize;
 205     }
 206
 207     return VLC_SUCCESS;
 208 }
 209
 210 /*****************************************************************************
 211  * Close: clean up the packetizer
 212  *****************************************************************************/
 213 static void Close( vlc_object_t *p_this )
 214 {
 215     decoder_t *p_dec = (decoder_t*)p_this;
 216     decoder_sys_t *p_sys = p_dec->p_sys;
 217
 218     block_BytestreamRelease( &p_sys->bytestream );
 219     free( p_sys );
 220 }
 221
 222 /****************************************************************************
 223  * Packetize: the whole thing
 224  ****************************************************************************/
 225 static block_t *Packetize( decoder_t *p_dec, block_t **pp_block )
 226 {
 227     decoder_sys_t *p_sys = p_dec->p_sys;
 228     block_t       *p_pic;
 229
 230     if( !pp_block || !*pp_block ) return NULL;
 231
 232     block_BytestreamPush( &p_sys->bytestream, *pp_block );
 233
 234     for( ;; )
 235     {
 236         switch( p_sys->i_state )
 237         {
 238             case STATE_NOSYNC:
 239                 if( block_FindStartcodeFromOffset( &p_sys->bytestream,
 240                         &p_sys->i_offset, p_sys->startcode, 4 ) == VLC_SUCCESS )
 241                 {
 242                     p_sys->i_state = STATE_NEXT_SYNC;
 243                 }
 244
 245                 if( p_sys->i_offset )
 246                 {
 247                     block_SkipBytes( &p_sys->bytestream, p_sys->i_offset );
 248                     p_sys->i_offset = 0;
 249                     block_BytestreamFlush( &p_sys->bytestream );
 250                 }
 251
 252                 if( p_sys->i_state != STATE_NEXT_SYNC )
 253                 {
 254                     /* Need more data */
 255                     return NULL;
 256                 }
 257
 258                 p_sys->i_offset = 1; /* To find next startcode */
 259
 260             case STATE_NEXT_SYNC:
 261                 /* Find the next startcode */
 262                 if( block_FindStartcodeFromOffset( &p_sys->bytestream,
 263                         &p_sys->i_offset, p_sys->startcode, 4 ) != VLC_SUCCESS )
 264                 {
 265                     /* Need more data */
 266                     return NULL;
 267                 }
 268
 269                 /* Get the new fragment and set the pts/dts */
 270                 p_pic = block_New( p_dec, p_sys->i_offset );
 271                 p_pic->i_pts = p_sys->bytestream.p_block->i_pts;
 272                 p_pic->i_dts = p_sys->bytestream.p_block->i_dts;
 273
 274                 block_GetBytes( &p_sys->bytestream, p_pic->p_buffer,
 275                                 p_pic->i_buffer );
 276
 277                 p_sys->i_offset = 0;
 278
 279                 /* Parse the NAL */
 280                 if( !( p_pic = ParseNALBlock( p_dec, p_pic ) ) )
 281                 {
 282                     p_sys->i_state = STATE_NOSYNC;
 283                     break;
 284                 }
 285
 286                 /* So p_block doesn't get re-added several times */
 287                 *pp_block = block_BytestreamPop( &p_sys->bytestream );
 288
 289                 p_sys->i_state = STATE_NOSYNC;
 290
 291                 return p_pic;
 292         }
 293     }
 294 }
 295
 296 /****************************************************************************
 297  * PacketizeAVC1: the whole thing
 298  ****************************************************************************/
 299 static block_t *PacketizeAVC1( decoder_t *p_dec, block_t **pp_block )
 300 {
 301     decoder_sys_t *p_sys = p_dec->p_sys;
 302     block_t       *p_block;
 303     block_t       *p_ret = NULL;
 304     uint8_t       *p;
 305
 306     if( !pp_block || !*pp_block ) return NULL;
 307
 308     p_block = *pp_block;
 309     *pp_block = NULL;
 310
 311     for( p = p_block->p_buffer; p < &p_block->p_buffer[p_block->i_buffer]; )
 312     {
 313         block_t *p_pic;
 314         int i_size = 0;
 315         int i;
 316
 317         for( i = 0; i < p_sys->i_avcC_length_size; i++ )
 318         {
 319             i_size = (i_size << 8) | (*p++);
 320         }
 321
 322         if( i_size > 0 )
 323         {
 324             block_t *p_part = nal_get_annexeb( p_dec, p, i_size );
 325
 326             p_part->i_dts = p_block->i_dts;
 327             p_part->i_pts = p_block->i_pts;
 328
 329             /* Parse the NAL */
 330             if( ( p_pic = ParseNALBlock( p_dec, p_part ) ) )
 331             {
 332                 block_ChainAppend( &p_ret, p_pic );
 333             }
 334         }
 335         p += i_size;
 336     }
 337
 338     return p_ret;
 339 }
 340
 341 static block_t *nal_get_annexeb( decoder_t *p_dec, uint8_t *p, int i_size )
 342 {
 343     block_t *p_nal;
 344
 345     p_nal = block_New( p_dec, 4 + i_size );
 346
 347     /* Add start code */
 348     p_nal->p_buffer[0] = 0x00;
 349     p_nal->p_buffer[1] = 0x00;
 350     p_nal->p_buffer[2] = 0x00;
 351     p_nal->p_buffer[3] = 0x01;
 352
 353     /* Copy nalu */
 354     memcpy( &p_nal->p_buffer[4], p, i_size );
 355
 356     return p_nal;
 357 }
 358
 359 static void nal_get_decoded( uint8_t **pp_ret, int *pi_ret,
 360                              uint8_t *src, int i_src )
 361 {
 362     uint8_t *end = &src[i_src];
 363     uint8_t *dst = malloc( i_src );
 364
 365     *pp_ret = dst;
 366
 367     while( src < end )
 368     {
 369         if( src < end - 3 && src[0] == 0x00 && src[1] == 0x00 &&
 370             src[2] == 0x03 )
 371         {
 372             *dst++ = 0x00;
 373             *dst++ = 0x00;
 374
 375             src += 3;
 376             continue;
 377         }
 378         *dst++ = *src++;
 379     }
 380
 381     *pi_ret = dst - *pp_ret;
 382 }
 383
 384 static inline int bs_read_ue( bs_t *s )
 385 {
 386     int i = 0;
 387
 388     while( bs_read1( s ) == 0 && s->p < s->p_end && i < 32 )
 389     {
 390         i++;
 391     }
 392     return( ( 1 << i) - 1 + bs_read( s, i ) );
 393 }
 394
 395 static inline int bs_read_se( bs_t *s )
 396 {
 397     int val = bs_read_ue( s );
 398
 399     return val&0x01 ? (val+1)/2 : -(val/2);
 400 }
 401
 402
 403 static block_t *ParseNALBlock( decoder_t *p_dec, block_t *p_frag )
 404 {
 405     decoder_sys_t *p_sys = p_dec->p_sys;
 406     block_t *p_pic = NULL;
 407
 408     const int i_ref_idc  = (p_frag->p_buffer[4] >> 5)&0x03;
 409     const int i_nal_type = p_frag->p_buffer[4]&0x1f;
 410
 411     if( p_sys->b_slice && !p_sys->b_sps )
 412     {
 413         block_ChainRelease( p_sys->p_frame );
 414         msg_Warn( p_dec, "waiting for SPS" );
 415
 416         /* Reset context */
 417         p_sys->p_frame = NULL;
 418         p_sys->b_slice = VLC_FALSE;
 419     }
 420
 421     if( !p_sys->b_sps &&
 422         i_nal_type >= NAL_SLICE && i_nal_type <= NAL_SLICE_IDR )
 423     {
 424         p_sys->b_slice = VLC_TRUE;
 425         /* Fragment will be discarded later on */
 426     }
 427     else if( i_nal_type >= NAL_SLICE && i_nal_type <= NAL_SLICE_IDR )
 428     {
 429         uint8_t *dec;
 430         int i_dec, i_first_mb, i_slice_type, i_frame_num, i_pic_flags = 0;
 431         vlc_bool_t b_pic = VLC_FALSE;
 432         bs_t s;
 433
 434         /* do not convert the whole frame */
 435         nal_get_decoded( &dec, &i_dec, &p_frag->p_buffer[5],
 436                          __MIN( p_frag->i_buffer - 5, 60 ) );
 437         bs_init( &s, dec, i_dec );
 438
 439         /* first_mb_in_slice */
 440         i_first_mb = bs_read_ue( &s );
 441
 442         /* slice_type */
 443         switch( (i_slice_type = bs_read_ue( &s )) )
 444         {
 445             case 0: case 5:
 446                 i_pic_flags = BLOCK_FLAG_TYPE_P;
 447                 break;
 448             case 1: case 6:
 449                 i_pic_flags = BLOCK_FLAG_TYPE_B;
 450                 break;
 451             case 2: case 7:
 452                 i_pic_flags = BLOCK_FLAG_TYPE_I;
 453                 break;
 454             case 3: case 8: /* SP */
 455                 i_pic_flags = BLOCK_FLAG_TYPE_P;
 456                 break;
 457             case 4: case 9:
 458                 i_pic_flags = BLOCK_FLAG_TYPE_I;
 459                 break;
 460         }
 461
 462         /* pic_parameter_set_id */
 463         bs_read_ue( &s );
 464         /* frame_num */
 465         i_frame_num = bs_read( &s, p_sys->i_log2_max_frame_num + 4 );
 466
 467         if( i_nal_type != NAL_SLICE_IDR && i_frame_num != p_sys->i_frame_num )
 468         {
 469             b_pic = VLC_TRUE;
 470         }
 471         p_sys->i_frame_num = i_frame_num;
 472
 473         if( !p_sys->b_frame_mbs_only )
 474         {
 475             /* field_pic_flag */
 476             if( bs_read( &s, 1 ) )
 477             {
 478                 /* bottom_field_flag */
 479                 bs_read( &s, 1 );
 480             }
 481         }
 482
 483         if( i_nal_type == NAL_SLICE_IDR )
 484         {
 485             /* id_pic_id */
 486             int i_idr_pic_id = bs_read_ue( &s );
 487             if( p_sys->i_nal_type != i_nal_type ) b_pic = VLC_TRUE;
 488             if( p_sys->i_idr_pic_id != i_idr_pic_id ) b_pic = VLC_TRUE;
 489             p_sys->i_idr_pic_id = i_idr_pic_id;
 490         }
 491         p_sys->i_nal_type = i_nal_type;
 492
 493         if( b_pic && p_sys->b_slice )
 494         {
 495             p_pic = block_ChainGather( p_sys->p_frame );
 496             p_pic->i_dts = p_sys->i_dts;
 497             p_pic->i_pts = p_sys->i_pts;
 498             p_pic->i_length = 0;    /* FIXME */
 499             p_pic->i_flags = p_sys->i_flags;
 500
 501             /* Reset context */
 502             p_sys->p_frame = NULL;
 503             p_sys->b_slice = VLC_FALSE;
 504         }
 505
 506         p_sys->b_slice = VLC_TRUE;
 507         p_sys->i_flags = i_pic_flags;
 508         p_sys->i_dts   = p_frag->i_dts;
 509         p_sys->i_pts   = p_frag->i_pts;
 510
 511         free( dec );
 512     }
 513     else if( i_nal_type == NAL_SPS )
 514     {
 515         uint8_t *dec;
 516         int     i_dec;
 517         bs_t s;
 518         int i_tmp;
 519
 520         msg_Dbg( p_dec, "found NAL_SPS" );
 521
 522         p_sys->b_sps = VLC_TRUE;
 523
 524         nal_get_decoded( &dec, &i_dec, &p_frag->p_buffer[5],
 525                          p_frag->i_buffer - 5 );
 526
 527         bs_init( &s, dec, i_dec );
 528         /* Skip profile(8), constraint_set012, reserver(5), level(8) */
 529         bs_skip( &s, 8 + 1+1+1 + 5 + 8 );
 530         /* sps id */
 531         bs_read_ue( &s );
 532         /* Skip i_log2_max_frame_num */
 533         p_sys->i_log2_max_frame_num = bs_read_ue( &s );
 534         /* Read poc_type */
 535         i_tmp = bs_read_ue( &s );
 536         if( i_tmp == 0 )
 537         {
 538             /* skip i_log2_max_poc_lsb */
 539             bs_read_ue( &s );
 540         }
 541         else if( i_tmp == 1 )
 542         {
 543             int i_cycle;
 544             /* skip b_delta_pic_order_always_zero */
 545             bs_skip( &s, 1 );
 546             /* skip i_offset_for_non_ref_pic */
 547             bs_read_se( &s );
 548             /* skip i_offset_for_top_to_bottom_field */
 549             bs_read_se( &s );
 550             /* read i_num_ref_frames_in_poc_cycle */
 551             i_cycle = bs_read_ue( &s );
 552             if( i_cycle > 256 ) i_cycle = 256;
 553             while( i_cycle > 0 )
 554             {
 555                 /* skip i_offset_for_ref_frame */
 556                 bs_read_se(&s );
 557             }
 558         }
 559         /* i_num_ref_frames */
 560         bs_read_ue( &s );
 561         /* b_gaps_in_frame_num_value_allowed */
 562         bs_skip( &s, 1 );
 563
 564         /* Read size */
 565         p_dec->fmt_out.video.i_width  = 16 * ( bs_read_ue( &s ) + 1 );
 566         p_dec->fmt_out.video.i_height = 16 * ( bs_read_ue( &s ) + 1 );
 567
 568         /* b_frame_mbs_only */
 569         p_sys->b_frame_mbs_only = bs_read( &s, 1 );
 570         if( p_sys->b_frame_mbs_only == 0 )
 571         {
 572             bs_skip( &s, 1 );
 573         }
 574         /* b_direct8x8_inference */
 575         bs_skip( &s, 1 );
 576
 577         /* crop ? */
 578         i_tmp = bs_read( &s, 1 );
 579         if( i_tmp )
 580         {
 581             /* left */
 582             p_dec->fmt_out.video.i_width -= 2 * bs_read_ue( &s );
 583             /* right */
 584             p_dec->fmt_out.video.i_width -= 2 * bs_read_ue( &s );
 585             /* top */
 586             p_dec->fmt_out.video.i_height -= 2 * bs_read_ue( &s );
 587             /* bottom */
 588             p_dec->fmt_out.video.i_height -= 2 * bs_read_ue( &s );
 589         }
 590
 591         /* vui */
 592         i_tmp = bs_read( &s, 1 );
 593         if( i_tmp )
 594         {
 595             /* read the aspect ratio part if any FIXME check it */
 596             i_tmp = bs_read( &s, 1 );
 597             if( i_tmp )
 598             {
 599                 static const struct { int w, h; } sar[14] =
 600                 {
 601                     { 0,   0 }, { 1,   1 }, { 12, 11 }, { 10, 11 },
 602                     { 16, 11 }, { 40, 33 }, { 24, 11 }, { 20, 11 },
 603                     { 32, 11 }, { 80, 33 }, { 18, 11 }, { 15, 11 },
 604                     { 64, 33 }, { 160,99 },
 605                 };
 606                 int i_sar = bs_read( &s, 8 );
 607                 int w, h;
 608
 609                 if( i_sar < 14 )
 610                 {
 611                     w = sar[i_sar].w;
 612                     h = sar[i_sar].h;
 613                 }
 614                 else
 615                 {
 616                     w = bs_read( &s, 16 );
 617                     h = bs_read( &s, 16 );
 618                 }
 619                 p_dec->fmt_out.video.i_aspect =
 620                     VOUT_ASPECT_FACTOR * w / h * p_dec->fmt_out.video.i_width /
 621                     p_dec->fmt_out.video.i_height;
 622             }
 623         }
 624
 625         free( dec );
 626     }
 627     else if( i_nal_type == NAL_PPS )
 628     {
 629         bs_t s;
 630         bs_init( &s, &p_frag->p_buffer[5], p_frag->i_buffer - 5 );
 631
 632         /* TODO */
 633         msg_Dbg( p_dec, "found NAL_PPS" );
 634     }
 635
 636     /* Append the block */
 637     block_ChainAppend( &p_sys->p_frame, p_frag );
 638
 639     return p_pic;
 640 }