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,
 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     if( p_dec->fmt_in.i_extra )
 156     {
 157         /* We have a vol */
 158         p_dec->fmt_out.i_extra = p_dec->fmt_in.i_extra;
 159         p_dec->fmt_out.p_extra = xmalloc( p_dec->fmt_in.i_extra );
 160         memcpy( p_dec->fmt_out.p_extra, p_dec->fmt_in.p_extra,
 161                 p_dec->fmt_in.i_extra );
 162
 163         msg_Dbg( p_dec, "opening with vol size: %d", p_dec->fmt_in.i_extra );
 164         ParseVOL( p_dec, &p_dec->fmt_out,
 165                   p_dec->fmt_out.p_extra, p_dec->fmt_out.i_extra );
 166     }
 167     else
 168     {
 169         /* No vol, we'll have to look for one later on */
 170         p_dec->fmt_out.i_extra = 0;
 171         p_dec->fmt_out.p_extra = 0;
 172     }
 173
 174     /* Set callback */
 175     p_dec->pf_packetize = Packetize;
 176
 177     return VLC_SUCCESS;
 178 }
 179
 180 /*****************************************************************************
 181  * Close: clean up the packetizer
 182  *****************************************************************************/
 183 static void Close( vlc_object_t *p_this )
 184 {
 185     decoder_t *p_dec = (decoder_t*)p_this;
 186     decoder_sys_t *p_sys = p_dec->p_sys;
 187
 188     packetizer_Clean( &p_sys->packetizer );
 189     if( p_sys->p_frame )
 190         block_ChainRelease( p_sys->p_frame );
 191     free( p_sys );
 192 }
 193
 194 /****************************************************************************
 195  * Packetize: the whole thing
 196  ****************************************************************************/
 197 static block_t *Packetize( decoder_t *p_dec, block_t **pp_block )
 198 {
 199     decoder_sys_t *p_sys = p_dec->p_sys;
 200
 201     return packetizer_Packetize( &p_sys->packetizer, pp_block );
 202 }
 203
 204 /*****************************************************************************
 205  * Helpers:
 206  *****************************************************************************/
 207 static void PacketizeReset( void *p_private, bool b_broken )
 208 {
 209     decoder_t *p_dec = p_private;
 210     decoder_sys_t *p_sys = p_dec->p_sys;
 211
 212     if( b_broken )
 213     {
 214         if( p_sys->p_frame )
 215             block_ChainRelease( p_sys->p_frame );
 216         p_sys->p_frame = NULL;
 217         p_sys->pp_last = &p_sys->p_frame;
 218     }
 219
 220     p_sys->i_interpolated_pts =
 221     p_sys->i_interpolated_dts =
 222     p_sys->i_last_ref_pts = VLC_TS_INVALID;
 223
 224     p_sys->i_last_time_ref =
 225     p_sys->i_time_ref =
 226     p_sys->i_last_time =
 227     p_sys->i_last_timeincr = 0;
 228 }
 229
 230 static block_t *PacketizeParse( void *p_private, bool *pb_ts_used, block_t *p_block )
 231 {
 232     decoder_t *p_dec = p_private;
 233     const mtime_t i_dts = p_block->i_dts;
 234     const mtime_t i_pts = p_block->i_pts;
 235
 236     block_t *p_au = ParseMPEGBlock( p_dec, p_block );
 237
 238     *pb_ts_used = p_au &&  p_au->i_dts == i_dts && p_au->i_pts == i_pts;
 239
 240     return p_au;
 241 }
 242
 243
 244 static int PacketizeValidate( void *p_private, block_t *p_au )
 245 {
 246     decoder_t *p_dec = p_private;
 247     decoder_sys_t *p_sys = p_dec->p_sys;
 248
 249     /* We've just started the stream, wait for the first PTS.
 250      * We discard here so we can still get the sequence header. */
 251     if( p_sys->i_interpolated_pts <= VLC_TS_INVALID &&
 252         p_sys->i_interpolated_dts <= VLC_TS_INVALID )
 253     {
 254         msg_Dbg( p_dec, "need a starting pts/dts" );
 255         return VLC_EGENERIC;
 256     }
 257
 258     /* When starting the stream we can have the first frame with
 259      * a null DTS (i_interpolated_pts is initialized to 0) */
 260     if( !p_au->i_dts )
 261         p_au->i_dts = p_au->i_pts;
 262     return VLC_SUCCESS;
 263 }
 264
 265 /*****************************************************************************
 266  * ParseMPEGBlock: Re-assemble fragments into a block containing a picture
 267  *****************************************************************************/
 268 static block_t *ParseMPEGBlock( decoder_t *p_dec, block_t *p_frag )
 269 {
 270     decoder_sys_t *p_sys = p_dec->p_sys;
 271     block_t *p_pic = NULL;
 272
 273     if( p_frag->p_buffer[3] == 0xB0 || p_frag->p_buffer[3] == 0xB1 || p_frag->p_buffer[3] == 0xB2 )
 274     {   /* VOS and USERDATA */
 275 #if 0
 276         /* Remove VOS start/end code from the original stream */
 277         block_Release( p_frag );
 278 #else
 279         /* Append the block for now since ts/ps muxers rely on VOL
 280          * being present in the stream */
 281         block_ChainLastAppend( &p_sys->pp_last, p_frag );
 282 #endif
 283         return NULL;
 284     }
 285     if( p_frag->p_buffer[3] >= 0x20 && p_frag->p_buffer[3] <= 0x2f )
 286     {
 287         /* Copy the complete VOL */
 288         if( (size_t)p_dec->fmt_out.i_extra != p_frag->i_buffer )
 289         {
 290             p_dec->fmt_out.p_extra =
 291                 xrealloc( p_dec->fmt_out.p_extra, p_frag->i_buffer );
 292             p_dec->fmt_out.i_extra = p_frag->i_buffer;
 293         }
 294         memcpy( p_dec->fmt_out.p_extra, p_frag->p_buffer, p_frag->i_buffer );
 295         ParseVOL( p_dec, &p_dec->fmt_out,
 296                   p_dec->fmt_out.p_extra, p_dec->fmt_out.i_extra );
 297
 298 #if 0
 299         /* Remove from the original stream */
 300         block_Release( p_frag );
 301 #else
 302         /* Append the block for now since ts/ps muxers rely on VOL
 303          * being present in the stream */
 304         block_ChainLastAppend( &p_sys->pp_last, p_frag );
 305 #endif
 306         return NULL;
 307     }
 308     else
 309     {
 310         if( !p_dec->fmt_out.i_extra )
 311         {
 312             msg_Warn( p_dec, "waiting for VOL" );
 313             block_Release( p_frag );
 314             return NULL;
 315         }
 316
 317         /* Append the block */
 318         block_ChainLastAppend( &p_sys->pp_last, p_frag );
 319     }
 320
 321     if( p_frag->p_buffer[3] == 0xb6 &&
 322         ParseVOP( p_dec, p_frag ) == VLC_SUCCESS )
 323     {
 324         /* We are dealing with a VOP */
 325         p_pic = block_ChainGather( p_sys->p_frame );
 326         p_pic->i_flags = p_sys->i_flags;
 327         p_pic->i_pts = p_sys->i_interpolated_pts;
 328         p_pic->i_dts = p_sys->i_interpolated_dts;
 329
 330         /* Reset context */
 331         p_sys->p_frame = NULL;
 332         p_sys->pp_last = &p_sys->p_frame;
 333     }
 334
 335     return p_pic;
 336 }
 337
 338 /* ParseVOL:
 339  *  TODO:
 340  *      - support aspect ratio
 341  */
 342 static int ParseVOL( decoder_t *p_dec, es_format_t *fmt,
 343                      uint8_t *p_vol, int i_vol )
 344 {
 345     decoder_sys_t *p_sys = p_dec->p_sys;
 346     int i_vo_type, i_vo_ver_id, i_ar, i_shape;
 347     bs_t s;
 348
 349     for( ;; )
 350     {
 351         if( p_vol[0] == 0x00 && p_vol[1] == 0x00 && p_vol[2] == 0x01 &&
 352             p_vol[3] >= 0x20 && p_vol[3] <= 0x2f ) break;
 353
 354         p_vol++; i_vol--;
 355         if( i_vol <= 4 ) return VLC_EGENERIC;
 356     }
 357
 358     bs_init( &s, &p_vol[4], i_vol - 4 );
 359
 360     bs_skip( &s, 1 );   /* random access */
 361     i_vo_type = bs_read( &s, 8 );
 362     if( bs_read1( &s ) )
 363     {
 364         i_vo_ver_id = bs_read( &s, 4 );
 365         bs_skip( &s, 3 );
 366     }
 367     else
 368     {
 369         i_vo_ver_id = 1;
 370     }
 371     i_ar = bs_read( &s, 4 );
 372     if( i_ar == 0xf )
 373     {
 374         int i_ar_width, i_ar_height;
 375
 376         i_ar_width = bs_read( &s, 8 );
 377         i_ar_height= bs_read( &s, 8 );
 378     }
 379     if( bs_read1( &s ) )
 380     {
 381         int i_chroma_format;
 382         int i_low_delay;
 383
 384         /* vol control parameter */
 385         i_chroma_format = bs_read( &s, 2 );
 386         i_low_delay = bs_read1( &s );
 387
 388         if( bs_read1( &s ) )
 389         {
 390             bs_skip( &s, 16 );
 391             bs_skip( &s, 16 );
 392             bs_skip( &s, 16 );
 393             bs_skip( &s, 3 );
 394             bs_skip( &s, 11 );
 395             bs_skip( &s, 1 );
 396             bs_skip( &s, 16 );
 397         }
 398     }
 399     /* shape 0->RECT, 1->BIN, 2->BIN_ONLY, 3->GRAY */
 400     i_shape = bs_read( &s, 2 );
 401     if( i_shape == 3 && i_vo_ver_id != 1 )
 402     {
 403         bs_skip( &s, 4 );
 404     }
 405
 406     if( !bs_read1( &s ) ) return VLC_EGENERIC; /* Marker */
 407
 408     p_sys->i_fps_num = bs_read( &s, 16 ); /* Time increment resolution*/
 409     if( !p_sys->i_fps_num ) p_sys->i_fps_num = 1;
 410
 411     if( !bs_read1( &s ) ) return VLC_EGENERIC; /* Marker */
 412
 413     if( bs_read1( &s ) )
 414     {
 415         int i_time_increment_bits = vlc_log2( p_sys->i_fps_num - 1 ) + 1;
 416
 417         if( i_time_increment_bits < 1 ) i_time_increment_bits = 1;
 418
 419         p_sys->i_fps_den = bs_read( &s, i_time_increment_bits );
 420     }
 421     if( i_shape == 0 )
 422     {
 423         bs_skip( &s, 1 );
 424         fmt->video.i_width = bs_read( &s, 13 );
 425         bs_skip( &s, 1 );
 426         fmt->video.i_height= bs_read( &s, 13 );
 427         bs_skip( &s, 1 );
 428     }
 429
 430     return VLC_SUCCESS;
 431 }
 432
 433 static int ParseVOP( decoder_t *p_dec, block_t *p_vop )
 434 {
 435     decoder_sys_t *p_sys = p_dec->p_sys;
 436     int64_t i_time_increment, i_time_ref;
 437     int i_modulo_time_base = 0, i_time_increment_bits;
 438     bs_t s;
 439
 440     bs_init( &s, &p_vop->p_buffer[4], p_vop->i_buffer - 4 );
 441
 442     switch( bs_read( &s, 2 ) )
 443     {
 444     case 0:
 445         p_sys->i_flags = BLOCK_FLAG_TYPE_I;
 446         break;
 447     case 1:
 448         p_sys->i_flags = BLOCK_FLAG_TYPE_P;
 449         break;
 450     case 2:
 451         p_sys->i_flags = BLOCK_FLAG_TYPE_B;
 452         p_sys->b_frame = true;
 453         break;
 454     case 3: /* gni ? */
 455         p_sys->i_flags = BLOCK_FLAG_TYPE_PB;
 456         break;
 457     }
 458
 459     while( bs_read( &s, 1 ) ) i_modulo_time_base++;
 460     if( !bs_read1( &s ) ) return VLC_EGENERIC; /* Marker */
 461
 462     /* VOP time increment */
 463     i_time_increment_bits = vlc_log2(p_dec->p_sys->i_fps_num - 1) + 1;
 464     if( i_time_increment_bits < 1 ) i_time_increment_bits = 1;
 465     i_time_increment = bs_read( &s, i_time_increment_bits );
 466
 467     /* Interpolate PTS/DTS */
 468     if( !(p_sys->i_flags & BLOCK_FLAG_TYPE_B) )
 469     {
 470         p_sys->i_last_time_ref = p_sys->i_time_ref;
 471         p_sys->i_time_ref +=
 472             (i_modulo_time_base * p_dec->p_sys->i_fps_num);
 473         i_time_ref = p_sys->i_time_ref;
 474     }
 475     else
 476     {
 477         i_time_ref = p_sys->i_last_time_ref +
 478             (i_modulo_time_base * p_dec->p_sys->i_fps_num);
 479     }
 480
 481 #if 0
 482     msg_Err( p_dec, "interp pts/dts (%lli,%lli), pts/dts (%lli,%lli)",
 483              p_sys->i_interpolated_pts, p_sys->i_interpolated_dts,
 484              p_vop->i_pts, p_vop->i_dts );
 485 #endif
 486
 487     if( p_dec->p_sys->i_fps_num < 5 && /* Work-around buggy streams */
 488         p_dec->fmt_in.video.i_frame_rate > 0 &&
 489         p_dec->fmt_in.video.i_frame_rate_base > 0 )
 490     {
 491         p_sys->i_interpolated_pts += INT64_C(1000000) *
 492         p_dec->fmt_in.video.i_frame_rate_base /
 493         p_dec->fmt_in.video.i_frame_rate;
 494     }
 495     else if( p_dec->p_sys->i_fps_num )
 496         p_sys->i_interpolated_pts +=
 497             ( INT64_C(1000000) * (i_time_ref + i_time_increment -
 498               p_sys->i_last_time - p_sys->i_last_timeincr) /
 499               p_dec->p_sys->i_fps_num );
 500
 501     p_sys->i_last_time = i_time_ref;
 502     p_sys->i_last_timeincr = i_time_increment;
 503
 504     /* Correct interpolated dts when we receive a new pts/dts */
 505     if( p_vop->i_pts > VLC_TS_INVALID )
 506         p_sys->i_interpolated_pts = p_vop->i_pts;
 507     if( p_vop->i_dts > VLC_TS_INVALID )
 508         p_sys->i_interpolated_dts = p_vop->i_dts;
 509
 510     if( (p_sys->i_flags & BLOCK_FLAG_TYPE_B) || !p_sys->b_frame )
 511     {
 512         /* Trivial case (DTS == PTS) */
 513
 514         p_sys->i_interpolated_dts = p_sys->i_interpolated_pts;
 515
 516         if( p_vop->i_pts > VLC_TS_INVALID )
 517             p_sys->i_interpolated_dts = p_vop->i_pts;
 518         if( p_vop->i_dts > VLC_TS_INVALID )
 519             p_sys->i_interpolated_dts = p_vop->i_dts;
 520
 521         p_sys->i_interpolated_pts = p_sys->i_interpolated_dts;
 522     }
 523     else
 524     {
 525         if( p_sys->i_last_ref_pts > VLC_TS_INVALID )
 526             p_sys->i_interpolated_dts = p_sys->i_last_ref_pts;
 527
 528         p_sys->i_last_ref_pts = p_sys->i_interpolated_pts;
 529     }
 530
 531     return VLC_SUCCESS;
 532 }
 533
 534 /* look at ffmpeg av_log2 ;) */
 535 static int vlc_log2( unsigned int v )
 536 {
 537     int n = 0;
 538     static const int vlc_log2_table[16] =
 539     {
 540         0,0,1,1,2,2,2,2, 3,3,3,3,3,3,3,3
 541     };
 542
 543     if( v&0xffff0000 )
 544     {
 545         v >>= 16;
 546         n += 16;
 547     }
 548     if( v&0xff00 )
 549     {
 550         v >>= 8;
 551         n += 8;
 552     }
 553     if( v&0xf0 )
 554     {
 555         v >>= 4;
 556         n += 4;
 557     }
 558     n += vlc_log2_table[v];
 559
 560     return n;
 561 }