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( 'V', 'S', 'S', 'H') &&
 121         p_dec->fmt_in.i_codec != VLC_FOURCC( 'v', 's', 's', 'h') &&
 122         ( p_dec->fmt_in.i_codec != VLC_FOURCC( 'a', 'v', 'c', '1') || p_dec->fmt_in.i_extra < 7 ) )
 123     {
 124         return VLC_EGENERIC;
 125     }
 126
 127     /* Allocate the memory needed to store the decoder's structure */
 128     if( ( p_dec->p_sys = p_sys = malloc( sizeof(decoder_sys_t) ) ) == NULL )
 129     {
 130         msg_Err( p_dec, "out of memory" );
 131         return VLC_EGENERIC;
 132     }
 133     p_sys->i_state = STATE_NOSYNC;
 134     p_sys->i_offset = 0;
 135     p_sys->startcode[0] = 0;
 136     p_sys->startcode[1] = 0;
 137     p_sys->startcode[2] = 0;
 138     p_sys->startcode[3] = 1;
 139     p_sys->bytestream = block_BytestreamInit( p_dec );
 140     p_sys->b_slice = VLC_FALSE;
 141     p_sys->p_frame = NULL;
 142     p_sys->i_dts   = 0;
 143     p_sys->i_pts   = 0;
 144     p_sys->i_flags = 0;
 145     p_sys->b_sps   = VLC_FALSE;
 146
 147     /* Setup properties */
 148     es_format_Copy( &p_dec->fmt_out, &p_dec->fmt_in );
 149     p_dec->fmt_out.i_codec = VLC_FOURCC( 'h', '2', '6', '4' );
 150
 151     if( p_dec->fmt_in.i_codec == VLC_FOURCC( 'a', 'v', 'c', '1' ) )
 152     {
 153         uint8_t *p = &((uint8_t*)p_dec->fmt_in.p_extra)[4];
 154         int i_sps, i_pps;
 155         int i;
 156
 157         /* Parse avcC */
 158         p_sys->i_avcC_length_size = 1 + ((*p++)&0x03);
 159
 160         /* Read SPS */
 161         i_sps = (*p++)&0x1f;
 162
 163         for( i = 0; i < i_sps; i++ )
 164         {
 165             int i_length = GetWBE( p );
 166             block_t *p_sps = nal_get_encoded( p_dec, p+2, i_length );
 167
 168             ParseNALBlock( p_dec, p_sps );
 169             p += 2 + i_length;
 170         }
 171         /* Read PPS */
 172         i_pps = *p++;
 173         for( i = 0; i < i_pps; i++ )
 174         {
 175             int i_length = GetWBE( p );
 176             block_t *p_pps = nal_get_encoded( p_dec, p+2, i_length );
 177
 178             ParseNALBlock( p_dec, p_pps );
 179             p += 2 + i_length;
 180         }
 181         msg_Dbg( p_dec, "avcC length size=%d sps=%d pps=%d",
 182                  p_sys->i_avcC_length_size, i_sps, i_pps );
 183
 184         /* Set callback */
 185         p_dec->pf_packetize = PacketizeAVC1;
 186     }
 187     else
 188     {
 189         /* Set callback */
 190         p_dec->pf_packetize = Packetize;
 191     }
 192
 193     return VLC_SUCCESS;
 194 }
 195
 196 /*****************************************************************************
 197  * Close: clean up the packetizer
 198  *****************************************************************************/
 199 static void Close( vlc_object_t *p_this )
 200 {
 201     decoder_t *p_dec = (decoder_t*)p_this;
 202     decoder_sys_t *p_sys = p_dec->p_sys;
 203
 204     block_BytestreamRelease( &p_sys->bytestream );
 205     free( p_sys );
 206 }
 207
 208 /****************************************************************************
 209  * Packetize: the whole thing
 210  ****************************************************************************/
 211 static block_t *Packetize( decoder_t *p_dec, block_t **pp_block )
 212 {
 213     decoder_sys_t *p_sys = p_dec->p_sys;
 214     block_t       *p_pic;
 215
 216     if( !pp_block || !*pp_block ) return NULL;
 217
 218     block_BytestreamPush( &p_sys->bytestream, *pp_block );
 219
 220     for( ;; )
 221     {
 222         switch( p_sys->i_state )
 223         {
 224             case STATE_NOSYNC:
 225                 if( block_FindStartcodeFromOffset( &p_sys->bytestream,
 226                         &p_sys->i_offset, p_sys->startcode, 4 ) == VLC_SUCCESS )
 227                 {
 228                     p_sys->i_state = STATE_NEXT_SYNC;
 229                 }
 230
 231                 if( p_sys->i_offset )
 232                 {
 233                     block_SkipBytes( &p_sys->bytestream, p_sys->i_offset );
 234                     p_sys->i_offset = 0;
 235                     block_BytestreamFlush( &p_sys->bytestream );
 236                 }
 237
 238                 if( p_sys->i_state != STATE_NEXT_SYNC )
 239                 {
 240                     /* Need more data */
 241                     return NULL;
 242                 }
 243
 244                 p_sys->i_offset = 1; /* To find next startcode */
 245
 246             case STATE_NEXT_SYNC:
 247                 /* Find the next startcode */
 248                 if( block_FindStartcodeFromOffset( &p_sys->bytestream,
 249                         &p_sys->i_offset, p_sys->startcode, 4 ) != VLC_SUCCESS )
 250                 {
 251                     /* Need more data */
 252                     return NULL;
 253                 }
 254
 255                 /* Get the new fragment and set the pts/dts */
 256                 p_pic = block_New( p_dec, p_sys->i_offset );
 257                 p_pic->i_pts = p_sys->bytestream.p_block->i_pts;
 258                 p_pic->i_dts = p_sys->bytestream.p_block->i_dts;
 259
 260                 block_GetBytes( &p_sys->bytestream, p_pic->p_buffer,
 261                                 p_pic->i_buffer );
 262
 263                 p_sys->i_offset = 0;
 264
 265                 /* Parse the NAL */
 266                 if( !( p_pic = ParseNALBlock( p_dec, p_pic ) ) )
 267                 {
 268                     p_sys->i_state = STATE_NOSYNC;
 269                     break;
 270                 }
 271
 272                 /* So p_block doesn't get re-added several times */
 273                 *pp_block = block_BytestreamPop( &p_sys->bytestream );
 274
 275                 p_sys->i_state = STATE_NOSYNC;
 276
 277                 return p_pic;
 278         }
 279     }
 280 }
 281
 282 /****************************************************************************
 283  * PacketizeAVC1: the whole thing
 284  ****************************************************************************/
 285 static block_t *PacketizeAVC1( decoder_t *p_dec, block_t **pp_block )
 286 {
 287     decoder_sys_t *p_sys = p_dec->p_sys;
 288     block_t       *p_block;
 289     block_t       *p_ret = NULL;
 290     uint8_t       *p;
 291
 292     if( !pp_block || !*pp_block ) return NULL;
 293
 294     p_block = *pp_block;
 295     *pp_block = NULL;
 296
 297     for( p = p_block->p_buffer; p < &p_block->p_buffer[p_block->i_buffer]; )
 298     {
 299         block_t *p_pic;
 300         int i_size = 0;
 301         int i;
 302
 303         for( i = 0; i < p_sys->i_avcC_length_size; i++ )
 304         {
 305             i_size = (i_size << 8) | (*p++);
 306         }
 307
 308         if( i_size > 0 )
 309         {
 310             block_t *p_part = nal_get_encoded( p_dec, p, i_size );
 311
 312             p_part->i_dts = p_block->i_dts;
 313             p_part->i_pts = p_block->i_pts;
 314             /* Parse the NAL */
 315             if( ( p_pic = ParseNALBlock( p_dec, p_part ) ) )
 316             {
 317                 block_ChainAppend( &p_ret, p_pic );
 318             }
 319         }
 320         p += i_size;
 321     }
 322
 323     return p_ret;
 324 }
 325
 326 static block_t *nal_get_encoded( decoder_t *p_dec, uint8_t *p, int i_size )
 327 {
 328     block_t *p_nal;
 329     int     i_nal_size = 5;
 330     uint8_t *src = &p[1];
 331     uint8_t *end = &p[i_size];
 332     uint8_t *dst;
 333     int     i_count = 0;
 334
 335     /* 1: compute real size */
 336     while( src < end )
 337     {
 338         if( i_count == 2 && *src <= 0x03 )
 339         {
 340             i_nal_size++;
 341             i_count = 0;
 342         }
 343         if( *src == 0 )
 344         {
 345             i_count++;
 346         }
 347         else
 348         {
 349             i_count = 0;
 350         }
 351         i_nal_size++;
 352         src++;
 353     }
 354
 355     /* 2: encode it */
 356     p_nal = block_New( p_dec, i_nal_size );
 357     i_count = 0;
 358     src = p;
 359     dst = p_nal->p_buffer;
 360
 361     /* add start code */
 362     *dst++ = 0x00;
 363     *dst++ = 0x00;
 364     *dst++ = 0x00;
 365     *dst++ = 0x01;
 366
 367     /* nal type */
 368     *dst++ = *src++;
 369
 370     while( src < end )
 371     {
 372         if( i_count == 2 && *src <= 0x03 )
 373         {
 374             *dst++ = 0x03;
 375             i_count = 0;
 376         }
 377         if( *src == 0 )
 378         {
 379             i_count++;
 380         }
 381         else
 382         {
 383             i_count = 0;
 384         }
 385         *dst++ = *src++;
 386     }
 387
 388     return p_nal;
 389 }
 390
 391 static void nal_get_decoded( uint8_t **pp_ret, int *pi_ret, uint8_t *src, int i_src )
 392 {
 393     uint8_t *end = &src[i_src];
 394     uint8_t *dst = malloc( i_src );
 395
 396     *pp_ret = dst;
 397
 398     while( src < end )
 399     {
 400         if( src < end - 3 && src[0] == 0x00 && src[1] == 0x00  && src[2] == 0x03 )
 401         {
 402             *dst++ = 0x00;
 403             *dst++ = 0x00;
 404
 405             src += 3;
 406             continue;
 407         }
 408         *dst++ = *src++;
 409     }
 410
 411     *pi_ret = dst - *pp_ret;
 412 }
 413
 414 static inline int bs_read_ue( bs_t *s )
 415 {
 416     int i = 0;
 417
 418     while( bs_read1( s ) == 0 && s->p < s->p_end && i < 32 )
 419     {
 420         i++;
 421     }
 422     return( ( 1 << i) - 1 + bs_read( s, i ) );
 423 }
 424 static inline int bs_read_se( bs_t *s )
 425 {
 426     int val = bs_read_ue( s );
 427
 428     return val&0x01 ? (val+1)/2 : -(val/2);
 429 }
 430
 431
 432 static block_t *ParseNALBlock( decoder_t *p_dec, block_t *p_frag )
 433 {
 434     decoder_sys_t *p_sys = p_dec->p_sys;
 435     block_t *p_pic = NULL;
 436
 437     const int i_ref_idc = (p_frag->p_buffer[4] >> 5)&0x03;
 438     const int i_nal_type= p_frag->p_buffer[4]&0x1f;
 439
 440     if( p_sys->b_slice &&
 441         ( i_nal_type == NAL_SLICE || i_nal_type == NAL_SLICE_IDR ||
 442           i_nal_type == NAL_SLICE_DPC || i_nal_type == NAL_SPS || i_nal_type == NAL_PPS ) )
 443     {
 444         if( p_sys->b_sps )
 445         {
 446             p_pic = block_ChainGather( p_sys->p_frame );
 447             p_pic->i_dts = p_sys->i_dts;
 448             p_pic->i_pts = p_sys->i_pts;
 449             p_pic->i_length = 0;    /* FIXME */
 450             p_pic->i_flags = p_sys->i_flags;
 451         }
 452         else
 453         {
 454             block_ChainRelease( p_sys->p_frame );
 455             msg_Warn( p_dec, "waiting SPS" );
 456         }
 457
 458         /* reset context */
 459         p_sys->p_frame = NULL;
 460         p_sys->b_slice = VLC_FALSE;
 461         //p_sys->i_dts += 40000;
 462     }
 463
 464     if( i_nal_type >= NAL_SLICE && i_nal_type <= NAL_SLICE_IDR )
 465     {
 466         uint8_t *dec;
 467         int     i_dec;
 468         bs_t s;
 469
 470         p_sys->b_slice = VLC_TRUE;
 471         p_sys->i_dts   = p_frag->i_dts;
 472         p_sys->i_pts   = p_frag->i_pts;
 473
 474         /* do not convert the whole frame */
 475         nal_get_decoded( &dec, &i_dec, &p_frag->p_buffer[5], __MIN( p_frag->i_buffer - 5, 60 ) );
 476         bs_init( &s, dec, i_dec );
 477
 478         /* i_first_mb */
 479         bs_read_ue( &s );
 480         /* picture type */
 481         switch( bs_read_ue( &s ) )
 482         {
 483             case 0: case 5:
 484                 p_sys->i_flags = BLOCK_FLAG_TYPE_P;
 485                 break;
 486             case 1: case 6:
 487                 p_sys->i_flags =BLOCK_FLAG_TYPE_B;
 488                 break;
 489             case 2: case 7:
 490                 p_sys->i_flags = BLOCK_FLAG_TYPE_I;
 491                 break;
 492             case 3: case 8: /* SP */
 493                 p_sys->i_flags = BLOCK_FLAG_TYPE_P;
 494                 break;
 495             case 4: case 9:
 496                 p_sys->i_flags = BLOCK_FLAG_TYPE_I;
 497                 break;
 498         }
 499
 500         free( dec );
 501     }
 502     else if( i_nal_type == NAL_SPS )
 503     {
 504         uint8_t *dec;
 505         int     i_dec;
 506         bs_t s;
 507         int i_tmp;
 508
 509         p_sys->b_sps = VLC_TRUE;
 510
 511         nal_get_decoded( &dec, &i_dec, &p_frag->p_buffer[5], p_frag->i_buffer - 5 );
 512
 513         bs_init( &s, dec, i_dec );
 514         /* Skip profile(8), constraint_set012, reserver(5), level(8) */
 515         bs_skip( &s, 8 + 1+1+1 + 5 + 8 );
 516         /* sps id */
 517         bs_read_ue( &s );
 518         /* Skip i_log2_max_frame_num */
 519         bs_read_ue( &s );
 520         /* Read poc_type */
 521         i_tmp = bs_read_ue( &s );
 522         if( i_tmp == 0 )
 523         {
 524             /* skip i_log2_max_poc_lsb */
 525             bs_read_ue( &s );
 526         }
 527         else if( i_tmp == 1 )
 528         {
 529             int i_cycle;
 530             /* skip b_delta_pic_order_always_zero */
 531             bs_skip( &s, 1 );
 532             /* skip i_offset_for_non_ref_pic */
 533             bs_read_se( &s );
 534             /* skip i_offset_for_top_to_bottom_field */
 535             bs_read_se( &s );
 536             /* read i_num_ref_frames_in_poc_cycle */
 537             i_cycle = bs_read_ue( &s );
 538             if( i_cycle > 256 ) i_cycle = 256;
 539             while( i_cycle > 0 )
 540             {
 541                 /* skip i_offset_for_ref_frame */
 542                 bs_read_se(&s );
 543             }
 544         }
 545         /* i_num_ref_frames */
 546         bs_read_ue( &s );
 547         /* b_gaps_in_frame_num_value_allowed */
 548         bs_skip( &s, 1 );
 549
 550         /* Read size */
 551         p_dec->fmt_out.video.i_width  = 16 * ( bs_read_ue( &s ) + 1 );
 552         p_dec->fmt_out.video.i_height = 16 * ( bs_read_ue( &s ) + 1 );
 553
 554         /* b_frame_mbs_only */
 555         i_tmp = bs_read( &s, 1 );
 556         if( i_tmp == 0 )
 557         {
 558             bs_skip( &s, 1 );
 559         }
 560         /* b_direct8x8_inference */
 561         bs_skip( &s, 1 );
 562
 563         /* crop ? */
 564         i_tmp = bs_read( &s, 1 );
 565         if( i_tmp )
 566         {
 567             /* left */
 568             p_dec->fmt_out.video.i_width -= 2 * bs_read_ue( &s );
 569             /* right */
 570             p_dec->fmt_out.video.i_width -= 2 * bs_read_ue( &s );
 571             /* top */
 572             p_dec->fmt_out.video.i_height -= 2 * bs_read_ue( &s );
 573             /* bottom */
 574             p_dec->fmt_out.video.i_height -= 2 * bs_read_ue( &s );
 575         }
 576
 577         /* vui */
 578         i_tmp = bs_read( &s, 1 );
 579         if( i_tmp )
 580         {
 581             /* read the aspect ratio part if any FIXME check it */
 582             i_tmp = bs_read( &s, 1 );
 583             if( i_tmp )
 584             {
 585                 static const struct { int w, h; } sar[14] =
 586                 {
 587                     { 0,   0 }, { 1,   1 }, { 12, 11 }, { 10, 11 },
 588                     { 16, 11 }, { 40, 33 }, { 24, 11 }, { 20, 11 },
 589                     { 32, 11 }, { 80, 33 }, { 18, 11 }, { 15, 11 },
 590                     { 64, 33 }, { 160,99 },
 591                 };
 592                 int i_sar = bs_read( &s, 8 );
 593                 int w, h;
 594
 595                 if( i_sar < 14 )
 596                 {
 597                     w = sar[i_sar].w;
 598                     h = sar[i_sar].h;
 599                 }
 600                 else
 601                 {
 602                     w = bs_read( &s, 16 );
 603                     h = bs_read( &s, 16 );
 604                 }
 605                 p_dec->fmt_out.video.i_aspect =
 606                     VOUT_ASPECT_FACTOR *
 607                     w / h *
 608                     p_dec->fmt_out.video.i_width / p_dec->fmt_out.video.i_height;
 609             }
 610         }
 611
 612         free( dec );
 613     }
 614     else if( i_nal_type == NAL_PPS )
 615     {
 616         bs_t s;
 617         bs_init( &s, &p_frag->p_buffer[5], p_frag->i_buffer - 5 );
 618
 619         /* TODO */
 620     }
 621
 622
 623     /* Append the block */
 624     block_ChainAppend( &p_sys->p_frame, p_frag );
 625
 626     return p_pic;
 627 }
 628