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

   1 /*****************************************************************************
   2  * mpegvideo.c
   3  *****************************************************************************
   4  * Copyright (C) 2001, 2002 VideoLAN
   5  * $Id: mpegvideo.c,v 1.19 2003/09/02 20:19:26 gbazin Exp $
   6  *
   7  * Authors: Laurent Aimar <fenrir@via.ecp.fr>
   8  *          Eric Petit <titer@videolan.org>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
  23  *****************************************************************************/
  24
  25 /*****************************************************************************
  26  * Problem with this implementation:
  27  *
  28  * Although we should time-stamp each picture with a PTS, this isn't possible
  29  * with the current implementation.
  30  * The problem comes from the fact that for non-low-delay streams we can't
  31  * calculate the PTS of pictures used as backward reference. Even the temporal
  32  * reference number doesn't help here because all the pictures don't
  33  * necessarily have the same duration (eg. 3:2 pulldown).
  34  *
  35  * However this doesn't really matter as far as the MPEG muxers are concerned
  36  * because they allow having empty PTS fields. --gibalou
  37  *****************************************************************************/
  38
  39 /*****************************************************************************
  40  * Preamble
  41  *****************************************************************************/
  42 #include <vlc/vlc.h>
  43 #include <vlc/decoder.h>
  44 #include <vlc/input.h>
  45 #include <vlc/sout.h>
  46 #include "codecs.h"                         /* WAVEFORMATEX BITMAPINFOHEADER */
  47
  48 #include <stdlib.h>                                      /* malloc(), free() */
  49 #include <string.h>                                              /* strdup() */
  50
  51 /*****************************************************************************
  52  * Local prototypes
  53  *****************************************************************************/
  54 typedef struct packetizer_s
  55 {
  56     /* Input properties */
  57     decoder_fifo_t          *p_fifo;
  58     bit_stream_t            bit_stream;
  59
  60     /* Output properties */
  61     sout_packetizer_input_t *p_sout_input;
  62     sout_format_t           output_format;
  63
  64     mtime_t                 i_interpolated_dts;
  65     mtime_t                 i_old_duration;
  66     mtime_t                 i_last_ref_pts;
  67     double                  d_frame_rate;
  68     int                     i_progressive_sequence;
  69     int                     i_low_delay;
  70     uint8_t                 p_sequence_header[150];
  71     int                     i_sequence_header_length;
  72     int                     i_last_sequence_header;
  73
  74 } packetizer_t;
  75
  76 static int  Open    ( vlc_object_t * );
  77 static int  Run     ( decoder_fifo_t * );
  78
  79 static int  InitThread     ( packetizer_t * );
  80 static void PacketizeThread   ( packetizer_t * );
  81 static void EndThread      ( packetizer_t * );
  82
  83 /*****************************************************************************
  84  * Module descriptor
  85  *****************************************************************************/
  86
  87 vlc_module_begin();
  88     set_description( _("MPEG-I/II video packetizer") );
  89     set_capability( "packetizer", 50 );
  90     set_callbacks( Open, NULL );
  91 vlc_module_end();
  92
  93 /*****************************************************************************
  94  * OpenDecoder: probe the packetizer and return score
  95  *****************************************************************************
  96  * Tries to launch a decoder and return score so that the interface is able
  97  * to choose.
  98  *****************************************************************************/
  99 static int Open( vlc_object_t *p_this )
 100 {
 101     decoder_t *p_dec = (decoder_t*)p_this;
 102
 103     if( p_dec->p_fifo->i_fourcc != VLC_FOURCC( 'm', 'p', 'g', 'v') &&
 104         p_dec->p_fifo->i_fourcc != VLC_FOURCC( 'm', 'p', 'g', '1') &&
 105         p_dec->p_fifo->i_fourcc != VLC_FOURCC( 'm', 'p', 'g', '2') )
 106     {
 107         return VLC_EGENERIC;
 108     }
 109
 110     p_dec->pf_run = Run;
 111     return VLC_SUCCESS;
 112 }
 113
 114 /*****************************************************************************
 115  * RunDecoder: this function is called just after the thread is created
 116  *****************************************************************************/
 117 static int Run( decoder_fifo_t *p_fifo )
 118 {
 119     packetizer_t *p_pack;
 120     int b_error;
 121
 122     msg_Info( p_fifo, "Running mpegvideo packetizer" );
 123     if( !( p_pack = malloc( sizeof( packetizer_t ) ) ) )
 124     {
 125         msg_Err( p_fifo, "out of memory" );
 126         DecoderError( p_fifo );
 127         return( -1 );
 128     }
 129     memset( p_pack, 0, sizeof( packetizer_t ) );
 130
 131     p_pack->p_fifo = p_fifo;
 132
 133     if( InitThread( p_pack ) != 0 )
 134     {
 135         DecoderError( p_fifo );
 136         return( -1 );
 137     }
 138
 139     while( ( !p_pack->p_fifo->b_die )&&( !p_pack->p_fifo->b_error ) )
 140     {
 141         PacketizeThread( p_pack );
 142     }
 143
 144
 145     if( ( b_error = p_pack->p_fifo->b_error ) )
 146     {
 147         DecoderError( p_pack->p_fifo );
 148     }
 149
 150     EndThread( p_pack );
 151
 152     if( p_pack )
 153     {
 154         free( p_pack );
 155     }
 156
 157     if( b_error )
 158     {
 159         return( -1 );
 160     }
 161
 162     return( 0 );
 163 }
 164
 165
 166 /*****************************************************************************
 167  * InitThread: initialize data before entering main loop
 168  *****************************************************************************/
 169
 170 static int InitThread( packetizer_t *p_pack )
 171 {
 172
 173     p_pack->output_format.i_cat = VIDEO_ES;
 174     p_pack->output_format.i_fourcc = VLC_FOURCC( 'm', 'p', 'g', 'v');
 175     p_pack->output_format.i_width  = 0;
 176     p_pack->output_format.i_height = 0;
 177     p_pack->output_format.i_bitrate= 0;
 178     p_pack->output_format.i_extra_data = 0;
 179     p_pack->output_format.p_extra_data = NULL;
 180
 181     p_pack->p_sout_input = NULL;
 182
 183     if( InitBitstream( &p_pack->bit_stream, p_pack->p_fifo,
 184                        NULL, NULL ) != VLC_SUCCESS )
 185     {
 186         msg_Err( p_pack->p_fifo, "cannot initialize bitstream" );
 187         return -1;
 188     }
 189
 190     return( 0 );
 191 }
 192
 193 /* from ISO 13818-2 */
 194 /* converting frame_rate_code to frame_rate */
 195 static const double pd_frame_rates[16] =
 196 {
 197     0, 24000.0/1001, 24, 25, 30000.0/1001, 30, 50, 60000.0/1001, 60,
 198     0, 0, 0, 0, 0, 0, 0
 199 };
 200
 201 static int CopyUntilNextStartCode( packetizer_t   *p_pack,
 202                                    sout_buffer_t  *p_sout_buffer,
 203                                    unsigned int   *pi_pos )
 204 {
 205     int i_copy = 0;
 206
 207     do
 208     {
 209         p_sout_buffer->p_buffer[(*pi_pos)++] =
 210                 GetBits( &p_pack->bit_stream, 8 );
 211         i_copy++;
 212
 213         if( *pi_pos + 2048 > p_sout_buffer->i_buffer_size )
 214         {
 215             sout_BufferRealloc( p_pack->p_sout_input->p_sout,
 216                                 p_sout_buffer,
 217                                 p_sout_buffer->i_buffer_size + 50 * 1024);
 218         }
 219
 220     } while( ShowBits( &p_pack->bit_stream, 24 ) != 0x01 &&
 221              !p_pack->p_fifo->b_die && !p_pack->p_fifo->b_error );
 222
 223     return( i_copy );
 224 }
 225
 226 /*****************************************************************************
 227  * PacketizeThread: packetize an unit (here copy a complete pes)
 228  *****************************************************************************/
 229 static void PacketizeThread( packetizer_t *p_pack )
 230 {
 231     sout_buffer_t *p_sout_buffer = NULL;
 232     vlc_bool_t    b_seen_slice = VLC_FALSE;
 233     int32_t       i_pos;
 234     int           i_skipped;
 235     mtime_t       i_duration; /* of the parsed picture */
 236
 237     mtime_t       i_pts = 0;
 238     mtime_t       i_dts = 0;
 239
 240     /* needed to calculate pts/dts */
 241     int i_temporal_ref = 0;
 242     int i_picture_coding_type = 0;
 243     int i_picture_structure = 0x03; /* frame picture */
 244     int i_top_field_first = 0;
 245     int i_repeat_first_field = 0;
 246     int i_progressive_frame = 0;
 247
 248     if( !p_pack->p_sout_input )
 249     {
 250         byte_t p_temp[512];/* 150 bytes is the maximal size
 251                                of a sequence_header + sequence_extension */
 252         int i_frame_rate_code;
 253
 254
 255         /* skip data until we find a sequence_header_code */
 256         /* TODO: store skipped somewhere so can send it to the mux
 257          * after the input is created */
 258         i_skipped = 0;
 259         while( ShowBits( &p_pack->bit_stream, 32 ) != 0x1B3 &&
 260                !p_pack->p_fifo->b_die && !p_pack->p_fifo->b_error )
 261         {
 262             RemoveBits( &p_pack->bit_stream, 8 );
 263             i_skipped++;
 264         }
 265         msg_Warn( p_pack->p_fifo, "sequence_header_code found (%d skipped)",
 266                  i_skipped );
 267
 268         /* copy the start_code */
 269         i_pos = 0;
 270         GetChunk( &p_pack->bit_stream, p_temp, 4 ); i_pos += 4;
 271
 272         /* horizontal_size_value */
 273         p_pack->output_format.i_width = ShowBits( &p_pack->bit_stream, 12 );
 274         /* vertical_size_value */
 275         p_pack->output_format.i_height= ShowBits( &p_pack->bit_stream, 24 ) & 0xFFF;
 276         /* frame_rate_code */
 277         i_frame_rate_code = ShowBits( &p_pack->bit_stream, 32 ) & 0xF;
 278
 279         /* copy headers */
 280         GetChunk( &p_pack->bit_stream, p_temp + i_pos, 7 ); i_pos += 7;
 281
 282         /* intra_quantiser_matrix [non_intra_quantiser_matrix] */
 283         if( ShowBits( &p_pack->bit_stream, 7 ) & 0x1 )
 284         {
 285
 286             GetChunk( &p_pack->bit_stream, p_temp + i_pos, 64 ); i_pos += 64;
 287
 288             if( ShowBits( &p_pack->bit_stream, 8 ) & 0x1 )
 289             {
 290                 GetChunk( &p_pack->bit_stream, p_temp + i_pos, 65); i_pos += 65;
 291             }
 292         }
 293         /* non_intra_quantiser_matrix */
 294         else if( ShowBits( &p_pack->bit_stream, 8 ) & 0x1 )
 295         {
 296             GetChunk( &p_pack->bit_stream, p_temp + i_pos, 65); i_pos += 65;
 297         }
 298         /* nothing */
 299         else
 300         {
 301             GetChunk( &p_pack->bit_stream, p_temp + i_pos, 1 ); i_pos += 1;
 302         }
 303
 304         /* sequence_extension (10 bytes) */
 305         if( ShowBits( &p_pack->bit_stream, 32 ) != 0x1B5 )
 306         {
 307             msg_Dbg( p_pack->p_fifo, "ARRGG no extension_start_code" );
 308             p_pack->i_progressive_sequence = 1;
 309             p_pack->i_low_delay = 1;
 310         }
 311         else
 312         {
 313             GetChunk( &p_pack->bit_stream, p_temp + i_pos, 10 );
 314             p_pack->i_progressive_sequence = ( p_temp[i_pos+5]&0x08 ) ? 1 : 0;
 315             p_pack->i_low_delay = ( p_temp[i_pos+9]&0x80 ) ? 1 : 0;
 316             i_pos += 10;
 317         }
 318
 319         /* remember sequence_header and sequence_extention */
 320         memcpy( p_pack->p_sequence_header, p_temp, i_pos );
 321         p_pack->i_sequence_header_length = i_pos;
 322
 323         p_pack->d_frame_rate =  pd_frame_rates[i_frame_rate_code];
 324
 325         msg_Warn( p_pack->p_fifo,
 326                   "creating input (image size %dx%d, frame rate %.2f)",
 327                   p_pack->output_format.i_width,
 328                   p_pack->output_format.i_height,
 329                   p_pack->d_frame_rate );
 330
 331         /* now we have informations to create the input */
 332         p_pack->p_sout_input = sout_InputNew( p_pack->p_fifo,
 333                                               &p_pack->output_format );
 334
 335         if( !p_pack->p_sout_input )
 336         {
 337             msg_Err( p_pack->p_fifo, "cannot add a new stream" );
 338             p_pack->p_fifo->b_error = VLC_TRUE;
 339             return;
 340         }
 341
 342         p_sout_buffer = sout_BufferNew( p_pack->p_sout_input->p_sout,
 343                                         100 * 1024 );
 344         p_sout_buffer->i_size = i_pos;
 345         memcpy( p_sout_buffer->p_buffer, p_temp, i_pos );
 346
 347     }
 348     else
 349     {
 350         p_sout_buffer =
 351             sout_BufferNew( p_pack->p_sout_input->p_sout, 100 * 1024 );
 352         i_pos = 0;
 353     }
 354
 355     p_pack->i_last_sequence_header++;
 356
 357     for( ;; )
 358     {
 359         uint32_t    i_code;
 360         if( p_pack->p_fifo->b_die || p_pack->p_fifo->b_error )
 361         {
 362             break;
 363         }
 364
 365         i_code = ShowBits( &p_pack->bit_stream, 32 );
 366
 367         if( b_seen_slice && ( i_code < 0x101 || i_code > 0x1af ) )
 368         {
 369             break;
 370         }
 371
 372         if( i_code == 0x1B8 ) /* GOP */
 373         {
 374             /* usefull for bad MPEG-1 : repeat the sequence_header
 375                every second */
 376             if( p_pack->i_last_sequence_header > (int) p_pack->d_frame_rate )
 377             {
 378                memcpy( p_sout_buffer->p_buffer + i_pos,
 379                        p_pack->p_sequence_header,
 380                        p_pack->i_sequence_header_length );
 381                i_pos += p_pack->i_sequence_header_length;
 382                p_pack->i_last_sequence_header = 0;
 383             }
 384             CopyUntilNextStartCode( p_pack, p_sout_buffer, &i_pos );
 385         }
 386         else if( i_code == 0x100 ) /* Picture */
 387         {
 388             /* picture_start_code */
 389             GetChunk( &p_pack->bit_stream,
 390                       p_sout_buffer->p_buffer + i_pos, 4 ); i_pos += 4;
 391
 392             NextPTS( &p_pack->bit_stream, &i_pts, &i_dts );
 393             i_temporal_ref = ShowBits( &p_pack->bit_stream, 10 );
 394             i_picture_coding_type = ShowBits( &p_pack->bit_stream, 13 ) & 0x3;
 395
 396             CopyUntilNextStartCode( p_pack, p_sout_buffer, &i_pos );
 397         }
 398         else if( i_code == 0x1b5 )
 399         {
 400             /* extention start code                   32 */
 401             GetChunk( &p_pack->bit_stream,
 402                       p_sout_buffer->p_buffer + i_pos, 4 ); i_pos += 4;
 403
 404             if( ShowBits( &p_pack->bit_stream, 4 ) == 0x08 )
 405             {
 406                 /* picture coding extention */
 407
 408                 /* extention start code identifier(b1000)  4 */
 409                 /* f_code[2][2]                           16 */
 410                 /* intra_dc_precision                      2 */
 411                 /* picture_structure                       2 */
 412                 /* top_field_first                         1 */
 413                 i_picture_structure =
 414                     ShowBits( &p_pack->bit_stream, 24 ) & 0x03;
 415                 i_top_field_first =
 416                     ShowBits( &p_pack->bit_stream, 25 ) & 0x01;
 417                 i_repeat_first_field =
 418                     ShowBits( &p_pack->bit_stream, 31 ) & 0x01;
 419
 420                 GetChunk( &p_pack->bit_stream,
 421                           p_sout_buffer->p_buffer + i_pos, 4 ); i_pos += 4;
 422
 423                 i_progressive_frame =
 424                     ShowBits( &p_pack->bit_stream, 1 ) & 0x01;
 425             }
 426             CopyUntilNextStartCode( p_pack, p_sout_buffer, &i_pos );
 427         }
 428         else
 429         {
 430             if( i_code >= 0x101 && i_code <= 0x1af )
 431             {
 432                 b_seen_slice = VLC_TRUE;
 433             }
 434
 435             if( i_code == 0x1B3 )
 436             {
 437                 p_pack->i_last_sequence_header = 0;
 438             }
 439             CopyUntilNextStartCode( p_pack, p_sout_buffer, &i_pos );
 440         }
 441     }
 442
 443     if( i_pts <= 0 && i_dts <= 0 && p_pack->i_interpolated_dts <= 0 )
 444     {
 445         msg_Dbg( p_pack->p_fifo, "need a starting pts/dts" );
 446         sout_BufferDelete( p_pack->p_sout_input->p_sout, p_sout_buffer );
 447         return;
 448     }
 449
 450     sout_BufferRealloc( p_pack->p_sout_input->p_sout,
 451                         p_sout_buffer, i_pos );
 452     p_sout_buffer->i_size = i_pos;
 453
 454     /* calculate frame duration */
 455     if( p_pack->i_progressive_sequence || i_picture_structure == 0x03)
 456     {
 457         i_duration = (mtime_t)( 1000000 / p_pack->d_frame_rate );
 458     }
 459     else
 460     {
 461         i_duration = (mtime_t)( 1000000 / p_pack->d_frame_rate / 2);
 462     }
 463
 464     if( p_pack->i_progressive_sequence )
 465     {
 466         if( i_top_field_first == 0 && i_repeat_first_field == 1 )
 467         {
 468             i_duration = 2 * i_duration;
 469         }
 470         else if( i_top_field_first == 1 && i_repeat_first_field == 1 )
 471         {
 472             i_duration = 3 * i_duration;
 473         }
 474     }
 475     else
 476     {
 477         if( i_picture_structure == 0x03 )
 478         {
 479             if( i_progressive_frame && i_repeat_first_field )
 480             {
 481                 i_duration += i_duration / 2;
 482             }
 483         }
 484     }
 485
 486     if( p_pack->i_low_delay || i_picture_coding_type == 0x03 )
 487     {
 488         /* Trivial case (DTS == PTS) */
 489         /* Correct interpolated dts when we receive a new pts/dts */
 490         if( i_pts > 0 ) p_pack->i_interpolated_dts = i_pts;
 491         if( i_dts > 0 ) p_pack->i_interpolated_dts = i_dts;
 492     }
 493     else
 494     {
 495         /* Correct interpolated dts when we receive a new pts/dts */
 496         if( p_pack->i_last_ref_pts )
 497             p_pack->i_interpolated_dts = p_pack->i_last_ref_pts;
 498         if( i_dts > 0 ) p_pack->i_interpolated_dts = i_dts;
 499
 500         p_pack->i_last_ref_pts = i_pts;
 501     }
 502
 503     /* Don't even try to calculate the PTS unless it is given in the
 504      * original stream */
 505     p_sout_buffer->i_pts = i_pts ? i_pts : -1;
 506
 507     p_sout_buffer->i_dts = p_pack->i_interpolated_dts;
 508
 509     if( p_pack->i_low_delay || i_picture_coding_type == 0x03 )
 510     {
 511         /* Trivial case (DTS == PTS) */
 512         p_pack->i_interpolated_dts += i_duration;
 513     }
 514     else
 515     {
 516         p_pack->i_interpolated_dts += p_pack->i_old_duration;
 517         p_pack->i_old_duration = i_duration;
 518     }
 519
 520     p_sout_buffer->i_length = p_pack->i_interpolated_dts -
 521                                 p_sout_buffer->i_dts;
 522
 523     p_sout_buffer->i_bitrate = (int)( 8 * i_pos * p_pack->d_frame_rate );
 524
 525 #if 0
 526     msg_Dbg( p_pack->p_fifo, "------------> dts=%lld pts=%lld duration=%lld",
 527              p_sout_buffer->i_dts, p_sout_buffer->i_pts,
 528              p_sout_buffer->i_length );
 529 #endif
 530
 531     sout_InputSendBuffer( p_pack->p_sout_input, p_sout_buffer );
 532 }
 533
 534
 535 /*****************************************************************************
 536  * EndThread : packetizer thread destruction
 537  *****************************************************************************/
 538 static void EndThread ( packetizer_t *p_pack)
 539 {
 540     if( p_pack->p_sout_input )
 541     {
 542         sout_InputDelete( p_pack->p_sout_input );
 543     }
 544 }