git.sesse.net Git - vlc/blob - modules/packetizer/mpeg4video.c

   1 /*****************************************************************************
   2  * mpeg4video.c: mpeg 4 video packetizer
   3  *****************************************************************************
   4  * Copyright (C) 2001-2006 the VideoLAN team
   5  * $Id$
   6  *
   7  * Authors: Gildas Bazin <gbazin@videolan.org>
   8  *          Laurent Aimar <fenrir@via.ecp.fr>
   9  *          Eric Petit <titer@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., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  24  *****************************************************************************/
  25
  26 /*****************************************************************************
  27  * Preamble
  28  *****************************************************************************/
  29
  30 #ifdef HAVE_CONFIG_H
  31 # include "config.h"
  32 #endif
  33
  34 #include <assert.h>
  35
  36 #include <vlc_common.h>
  37 #include <vlc_plugin.h>
  38 #include <vlc_sout.h>
  39 #include <vlc_codec.h>
  40 #include <vlc_block.h>
  41 #include <vlc_memory.h>
  42
  43 #include <vlc_bits.h>
  44 #include <vlc_block_helper.h>
  45 #include "packetizer_helper.h"
  46
  47 /*****************************************************************************
  48  * Module descriptor
  49  *****************************************************************************/
  50 static int  Open ( vlc_object_t * );
  51 static void Close( vlc_object_t * );
  52
  53 vlc_module_begin ()
  54     set_category( CAT_SOUT )
  55     set_subcategory( SUBCAT_SOUT_PACKETIZER )
  56     set_description( N_("MPEG4 video packetizer") )
  57     set_capability( "packetizer", 50 )
  58     set_callbacks( Open, Close )
  59 vlc_module_end ()
  60
  61 /****************************************************************************
  62  * Local prototypes
  63  ****************************************************************************/
  64 struct decoder_sys_t
  65 {
  66     /*
  67      * Input properties
  68      */
  69     packetizer_t packetizer;
  70
  71     /*
  72      * Common properties
  73      */
  74     mtime_t i_interpolated_pts;
  75     mtime_t i_interpolated_dts;
  76     mtime_t i_last_ref_pts;
  77     mtime_t i_last_time_ref;
  78     mtime_t i_time_ref;
  79     mtime_t i_last_time;
  80     mtime_t i_last_timeincr;
  81
  82     unsigned int i_flags;
  83
  84     int         i_fps_num;
  85     int         i_fps_den;
  86     int         i_last_incr;
  87     int         i_last_incr_diff;
  88
  89     bool  b_frame;
  90
  91     /* Current frame being built */
  92     block_t    *p_frame;
  93     block_t    **pp_last;
  94 };
  95
  96 static block_t *Packetize( decoder_t *, block_t ** );
  97
  98 static void PacketizeReset( void *p_private, bool b_broken );
  99 static block_t *PacketizeParse( void *p_private, bool *pb_ts_used, block_t * );
 100 static int PacketizeValidate( void *p_private, block_t * );
 101
 102 static block_t *ParseMPEGBlock( decoder_t *, block_t * );
 103 static int ParseVOL( decoder_t *, es_format_t *, uint8_t *, int );
 104 static int ParseVOP( decoder_t *, block_t * );
 105 static int vlc_log2( unsigned int );
 106
 107 #define VIDEO_OBJECT_MASK                       0x01f
 108 #define VIDEO_OBJECT_LAYER_MASK                 0x00f
 109
 110 #define VIDEO_OBJECT_START_CODE                 0x100
 111 #define VIDEO_OBJECT_LAYER_START_CODE           0x120
 112 #define VISUAL_OBJECT_SEQUENCE_START_CODE       0x1b0
 113 #define VISUAL_OBJECT_SEQUENCE_END_CODE         0x1b1
 114 #define USER_DATA_START_CODE                    0x1b2
 115 #define GROUP_OF_VOP_START_CODE                 0x1b3
 116 #define VIDEO_SESSION_ERROR_CODE                0x1b4
 117 #define VISUAL_OBJECT_START_CODE                0x1b5
 118 #define VOP_START_CODE                          0x1b6
 119 #define FACE_OBJECT_START_CODE                  0x1ba
 120 #define FACE_OBJECT_PLANE_START_CODE            0x1bb
 121 #define MESH_OBJECT_START_CODE                  0x1bc
 122 #define MESH_OBJECT_PLANE_START_CODE            0x1bd
 123 #define STILL_TEXTURE_OBJECT_START_CODE         0x1be
 124 #define TEXTURE_SPATIAL_LAYER_START_CODE        0x1bf
 125 #define TEXTURE_SNR_LAYER_START_CODE            0x1c0
 126
 127 static const uint8_t p_mp4v_startcode[3] = { 0x00, 0x00, 0x01 };
 128
 129 /*****************************************************************************
 130  * Open: probe the packetizer and return score
 131  *****************************************************************************/
 132 static int Open( vlc_object_t *p_this )
 133 {
 134     decoder_t     *p_dec = (decoder_t*)p_this;
 135     decoder_sys_t *p_sys;
 136
 137     if( p_dec->fmt_in.i_codec != VLC_CODEC_MP4V )
 138         return VLC_EGENERIC;
 139
 140     /* Allocate the memory needed to store the decoder's structure */
 141     if( ( p_dec->p_sys = p_sys = malloc( sizeof(decoder_sys_t) ) ) == NULL )
 142         return VLC_ENOMEM;
 143     memset( p_sys, 0, sizeof(decoder_sys_t) );
 144
 145     /* Misc init */
 146     packetizer_Init( &p_sys->packetizer,
 147                      p_mp4v_startcode, sizeof(p_mp4v_startcode),
 148                      NULL, 0,
 149                      PacketizeReset, PacketizeParse, PacketizeValidate, p_dec );
 150
 151     p_sys->p_frame = NULL;
 152     p_sys->pp_last = &p_sys->p_frame;
 153
 154     /* Setup properties */
 155     es_format_Copy( &p_dec->fmt_out, &p_dec->fmt_in );
 156     p_dec->fmt_out.i_codec = VLC_CODEC_MP4V;
 157
 158     if( p_dec->fmt_in.i_extra )
 159     {
 160         /* We have a vol */
 161         p_dec->fmt_out.i_extra = p_dec->fmt_in.i_extra;
 162         p_dec->fmt_out.p_extra = malloc( p_dec->fmt_in.i_extra );
 163         assert( p_dec->fmt_out.p_extra );
 164         memcpy( p_dec->fmt_out.p_extra, p_dec->fmt_in.p_extra,
 165                 p_dec->fmt_in.i_extra );
 166
 167         msg_Dbg( p_dec, "opening with vol size: %d", p_dec->fmt_in.i_extra );
 168         ParseVOL( p_dec, &p_dec->fmt_out,
 169                   p_dec->fmt_out.p_extra, p_dec->fmt_out.i_extra );
 170     }
 171     else
 172     {
 173         /* No vol, we'll have to look for one later on */
 174         p_dec->fmt_out.i_extra = 0;
 175         p_dec->fmt_out.p_extra = 0;
 176     }
 177
 178     /* Set callback */
 179     p_dec->pf_packetize = Packetize;
 180
 181     return VLC_SUCCESS;
 182 }
 183
 184 /*****************************************************************************
 185  * Close: clean up the packetizer
 186  *****************************************************************************/
 187 static void Close( vlc_object_t *p_this )
 188 {
 189     decoder_t *p_dec = (decoder_t*)p_this;
 190     decoder_sys_t *p_sys = p_dec->p_sys;
 191
 192     packetizer_Clean( &p_sys->packetizer );
 193     if( p_sys->p_frame )
 194         block_ChainRelease( p_sys->p_frame );
 195     free( p_sys );
 196 }
 197
 198 /****************************************************************************
 199  * Packetize: the whole thing
 200  ****************************************************************************/
 201 static block_t *Packetize( decoder_t *p_dec, block_t **pp_block )
 202 {
 203     decoder_sys_t *p_sys = p_dec->p_sys;
 204
 205     return packetizer_Packetize( &p_sys->packetizer, pp_block );
 206 }
 207
 208 /*****************************************************************************
 209  * Helpers:
 210  *****************************************************************************/
 211 static void PacketizeReset( void *p_private, bool b_broken )
 212 {
 213     decoder_t *p_dec = p_private;
 214     decoder_sys_t *p_sys = p_dec->p_sys;
 215
 216     if( b_broken )
 217     {
 218         if( p_sys->p_frame )
 219             block_ChainRelease( p_sys->p_frame );
 220         p_sys->p_frame = NULL;
 221         p_sys->pp_last = &p_sys->p_frame;
 222     }
 223
 224     p_sys->i_interpolated_pts =
 225     p_sys->i_interpolated_dts =
 226     p_sys->i_last_ref_pts =
 227     p_sys->i_last_time_ref =
 228     p_sys->i_time_ref =
 229     p_sys->i_last_time =
 230     p_sys->i_last_timeincr = 0;
 231 }
 232
 233 static block_t *PacketizeParse( void *p_private, bool *pb_ts_used, block_t *p_block )
 234 {
 235     decoder_t *p_dec = p_private;
 236     const mtime_t i_dts = p_block->i_dts;
 237     const mtime_t i_pts = p_block->i_pts;
 238
 239     block_t *p_au = ParseMPEGBlock( p_dec, p_block );
 240
 241     *pb_ts_used = p_au &&  p_au->i_dts == i_dts && p_au->i_pts == i_pts;
 242
 243     return p_au;
 244 }
 245
 246
 247 static int PacketizeValidate( void *p_private, block_t *p_au )
 248 {
 249     decoder_t *p_dec = p_private;
 250     decoder_sys_t *p_sys = p_dec->p_sys;
 251
 252     /* We've just started the stream, wait for the first PTS.
 253      * We discard here so we can still get the sequence header. */
 254     if( p_sys->i_interpolated_pts <= 0 &&
 255         p_sys->i_interpolated_dts <= 0 )
 256     {
 257         msg_Dbg( p_dec, "need a starting pts/dts" );
 258         return VLC_EGENERIC;
 259     }
 260
 261     /* When starting the stream we can have the first frame with
 262      * a null DTS (i_interpolated_pts is initialized to 0) */
 263     if( !p_au->i_dts )
 264         p_au->i_dts = p_au->i_pts;
 265     return VLC_SUCCESS;
 266 }
 267
 268 /*****************************************************************************
 269  * ParseMPEGBlock: Re-assemble fragments into a block containing a picture
 270  *****************************************************************************/
 271 static block_t *ParseMPEGBlock( decoder_t *p_dec, block_t *p_frag )
 272 {
 273     decoder_sys_t *p_sys = p_dec->p_sys;
 274     block_t *p_pic = NULL;
 275
 276     if( p_frag->p_buffer[3] == 0xB0 || p_frag->p_buffer[3] == 0xB1 || p_frag->p_buffer[3] == 0xB2 )
 277     {   /* VOS and USERDATA */
 278 #if 0
 279         /* Remove VOS start/end code from the original stream */
 280         block_Release( p_frag );
 281 #else
 282         /* Append the block for now since ts/ps muxers rely on VOL
 283          * being present in the stream */
 284         block_ChainLastAppend( &p_sys->pp_last, p_frag );
 285 #endif
 286         return NULL;
 287     }
 288     if( p_frag->p_buffer[3] >= 0x20 && p_frag->p_buffer[3] <= 0x2f )
 289     {
 290         /* Copy the complete VOL */
 291         if( (size_t)p_dec->fmt_out.i_extra != p_frag->i_buffer )
 292         {
 293             p_dec->fmt_out.p_extra =
 294                 realloc_or_free( p_dec->fmt_out.p_extra, p_frag->i_buffer );
 295             assert( p_dec->fmt_out.p_extra );
 296             p_dec->fmt_out.i_extra = p_frag->i_buffer;
 297         }
 298         memcpy( p_dec->fmt_out.p_extra, p_frag->p_buffer, p_frag->i_buffer );
 299         ParseVOL( p_dec, &p_dec->fmt_out,
 300                   p_dec->fmt_out.p_extra, p_dec->fmt_out.i_extra );
 301
 302 #if 0
 303         /* Remove from the original stream */
 304         block_Release( p_frag );
 305 #else
 306         /* Append the block for now since ts/ps muxers rely on VOL
 307          * being present in the stream */
 308         block_ChainLastAppend( &p_sys->pp_last, p_frag );
 309 #endif
 310         return NULL;
 311     }
 312     else
 313     {
 314         if( !p_dec->fmt_out.i_extra )
 315         {
 316             msg_Warn( p_dec, "waiting for VOL" );
 317             block_Release( p_frag );
 318             return NULL;
 319         }
 320
 321         /* Append the block */
 322         block_ChainLastAppend( &p_sys->pp_last, p_frag );
 323     }
 324
 325     if( p_frag->p_buffer[3] == 0xb6 &&
 326         ParseVOP( p_dec, p_frag ) == VLC_SUCCESS )
 327     {
 328         /* We are dealing with a VOP */
 329         p_pic = block_ChainGather( p_sys->p_frame );
 330         p_pic->i_flags = p_sys->i_flags;
 331         p_pic->i_pts = p_sys->i_interpolated_pts;
 332         p_pic->i_dts = p_sys->i_interpolated_dts;
 333
 334         /* Reset context */
 335         p_sys->p_frame = NULL;
 336         p_sys->pp_last = &p_sys->p_frame;
 337     }
 338
 339     return p_pic;
 340 }
 341
 342 /* ParseVOL:
 343  *  TODO:
 344  *      - support aspect ratio
 345  */
 346 static int ParseVOL( decoder_t *p_dec, es_format_t *fmt,
 347                      uint8_t *p_vol, int i_vol )
 348 {
 349     decoder_sys_t *p_sys = p_dec->p_sys;
 350     int i_vo_type, i_vo_ver_id, i_ar, i_shape;
 351     bs_t s;
 352
 353     for( ;; )
 354     {
 355         if( p_vol[0] == 0x00 && p_vol[1] == 0x00 && p_vol[2] == 0x01 &&
 356             p_vol[3] >= 0x20 && p_vol[3] <= 0x2f ) break;
 357
 358         p_vol++; i_vol--;
 359         if( i_vol <= 4 ) return VLC_EGENERIC;
 360     }
 361
 362     bs_init( &s, &p_vol[4], i_vol - 4 );
 363
 364     bs_skip( &s, 1 );   /* random access */
 365     i_vo_type = bs_read( &s, 8 );
 366     if( bs_read1( &s ) )
 367     {
 368         i_vo_ver_id = bs_read( &s, 4 );
 369         bs_skip( &s, 3 );
 370     }
 371     else
 372     {
 373         i_vo_ver_id = 1;
 374     }
 375     i_ar = bs_read( &s, 4 );
 376     if( i_ar == 0xf )
 377     {
 378         int i_ar_width, i_ar_height;
 379
 380         i_ar_width = bs_read( &s, 8 );
 381         i_ar_height= bs_read( &s, 8 );
 382     }
 383     if( bs_read1( &s ) )
 384     {
 385         int i_chroma_format;
 386         int i_low_delay;
 387
 388         /* vol control parameter */
 389         i_chroma_format = bs_read( &s, 2 );
 390         i_low_delay = bs_read1( &s );
 391
 392         if( bs_read1( &s ) )
 393         {
 394             bs_skip( &s, 16 );
 395             bs_skip( &s, 16 );
 396             bs_skip( &s, 16 );
 397             bs_skip( &s, 3 );
 398             bs_skip( &s, 11 );
 399             bs_skip( &s, 1 );
 400             bs_skip( &s, 16 );
 401         }
 402     }
 403     /* shape 0->RECT, 1->BIN, 2->BIN_ONLY, 3->GRAY */
 404     i_shape = bs_read( &s, 2 );
 405     if( i_shape == 3 && i_vo_ver_id != 1 )
 406     {
 407         bs_skip( &s, 4 );
 408     }
 409
 410     if( !bs_read1( &s ) ) return VLC_EGENERIC; /* Marker */
 411
 412     p_sys->i_fps_num = bs_read( &s, 16 ); /* Time increment resolution*/
 413     if( !p_sys->i_fps_num ) p_sys->i_fps_num = 1;
 414
 415     if( !bs_read1( &s ) ) return VLC_EGENERIC; /* Marker */
 416
 417     if( bs_read1( &s ) )
 418     {
 419         int i_time_increment_bits = vlc_log2( p_sys->i_fps_num - 1 ) + 1;
 420
 421         if( i_time_increment_bits < 1 ) i_time_increment_bits = 1;
 422
 423         p_sys->i_fps_den = bs_read( &s, i_time_increment_bits );
 424     }
 425     if( i_shape == 0 )
 426     {
 427         bs_skip( &s, 1 );
 428         fmt->video.i_width = bs_read( &s, 13 );
 429         bs_skip( &s, 1 );
 430         fmt->video.i_height= bs_read( &s, 13 );
 431         bs_skip( &s, 1 );
 432     }
 433
 434     return VLC_SUCCESS;
 435 }
 436
 437 static int ParseVOP( decoder_t *p_dec, block_t *p_vop )
 438 {
 439     decoder_sys_t *p_sys = p_dec->p_sys;
 440     int64_t i_time_increment, i_time_ref;
 441     int i_modulo_time_base = 0, i_time_increment_bits;
 442     bs_t s;
 443
 444     bs_init( &s, &p_vop->p_buffer[4], p_vop->i_buffer - 4 );
 445
 446     switch( bs_read( &s, 2 ) )
 447     {
 448     case 0:
 449         p_sys->i_flags = BLOCK_FLAG_TYPE_I;
 450         break;
 451     case 1:
 452         p_sys->i_flags = BLOCK_FLAG_TYPE_P;
 453         break;
 454     case 2:
 455         p_sys->i_flags = BLOCK_FLAG_TYPE_B;
 456         p_sys->b_frame = true;
 457         break;
 458     case 3: /* gni ? */
 459         p_sys->i_flags = BLOCK_FLAG_TYPE_PB;
 460         break;
 461     }
 462
 463     while( bs_read( &s, 1 ) ) i_modulo_time_base++;
 464     if( !bs_read1( &s ) ) return VLC_EGENERIC; /* Marker */
 465
 466     /* VOP time increment */
 467     i_time_increment_bits = vlc_log2(p_dec->p_sys->i_fps_num - 1) + 1;
 468     if( i_time_increment_bits < 1 ) i_time_increment_bits = 1;
 469     i_time_increment = bs_read( &s, i_time_increment_bits );
 470
 471     /* Interpolate PTS/DTS */
 472     if( !(p_sys->i_flags & BLOCK_FLAG_TYPE_B) )
 473     {
 474         p_sys->i_last_time_ref = p_sys->i_time_ref;
 475         p_sys->i_time_ref +=
 476             (i_modulo_time_base * p_dec->p_sys->i_fps_num);
 477         i_time_ref = p_sys->i_time_ref;
 478     }
 479     else
 480     {
 481         i_time_ref = p_sys->i_last_time_ref +
 482             (i_modulo_time_base * p_dec->p_sys->i_fps_num);
 483     }
 484
 485 #if 0
 486     msg_Err( p_dec, "interp pts/dts (%lli,%lli), pts/dts (%lli,%lli)",
 487              p_sys->i_interpolated_pts, p_sys->i_interpolated_dts,
 488              p_vop->i_pts, p_vop->i_dts );
 489 #endif
 490
 491     if( p_dec->p_sys->i_fps_num < 5 && /* Work-around buggy streams */
 492         p_dec->fmt_in.video.i_frame_rate > 0 &&
 493         p_dec->fmt_in.video.i_frame_rate_base > 0 )
 494     {
 495         p_sys->i_interpolated_pts += INT64_C(1000000) *
 496         p_dec->fmt_in.video.i_frame_rate_base /
 497         p_dec->fmt_in.video.i_frame_rate;
 498     }
 499     else if( p_dec->p_sys->i_fps_num )
 500         p_sys->i_interpolated_pts +=
 501             ( INT64_C(1000000) * (i_time_ref + i_time_increment -
 502               p_sys->i_last_time - p_sys->i_last_timeincr) /
 503               p_dec->p_sys->i_fps_num );
 504
 505     p_sys->i_last_time = i_time_ref;
 506     p_sys->i_last_timeincr = i_time_increment;
 507
 508     /* Correct interpolated dts when we receive a new pts/dts */
 509     if( p_vop->i_pts > 0 )
 510         p_sys->i_interpolated_pts = p_vop->i_pts;
 511     if( p_vop->i_dts > 0 )
 512         p_sys->i_interpolated_dts = p_vop->i_dts;
 513
 514     if( (p_sys->i_flags & BLOCK_FLAG_TYPE_B) || !p_sys->b_frame )
 515     {
 516         /* Trivial case (DTS == PTS) */
 517
 518         p_sys->i_interpolated_dts = p_sys->i_interpolated_pts;
 519
 520         if( p_vop->i_pts > 0 )
 521             p_sys->i_interpolated_dts = p_vop->i_pts;
 522         if( p_vop->i_dts > 0 )
 523             p_sys->i_interpolated_dts = p_vop->i_dts;
 524
 525         p_sys->i_interpolated_pts = p_sys->i_interpolated_dts;
 526     }
 527     else
 528     {
 529         if( p_sys->i_last_ref_pts > 0 )
 530             p_sys->i_interpolated_dts = p_sys->i_last_ref_pts;
 531
 532         p_sys->i_last_ref_pts = p_sys->i_interpolated_pts;
 533     }
 534
 535     return VLC_SUCCESS;
 536 }
 537
 538 /* look at ffmpeg av_log2 ;) */
 539 static int vlc_log2( unsigned int v )
 540 {
 541     int n = 0;
 542     static const int vlc_log2_table[16] =
 543     {
 544         0,0,1,1,2,2,2,2, 3,3,3,3,3,3,3,3
 545     };
 546
 547     if( v&0xffff0000 )
 548     {
 549         v >>= 16;
 550         n += 16;
 551     }
 552     if( v&0xff00 )
 553     {
 554         v >>= 8;
 555         n += 8;
 556     }
 557     if( v&0xf0 )
 558     {
 559         v >>= 4;
 560         n += 4;
 561     }
 562     n += vlc_log2_table[v];
 563
 564     return n;
 565 }