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