libhb/reader.c

   1 /* $Id: reader.c,v 1.21 2005/11/25 15:05:25 titer Exp $
   2
   3    This file is part of the HandBrake source code.
   4    Homepage: <http://handbrake.fr/>.
   5    It may be used under the terms of the GNU General Public License. */
   6
   7 #include "hb.h"
   8
   9 typedef struct
  10 {
  11     double average; // average time between packets
  12     int64_t last;   // last timestamp seen on this stream
  13     int id;         // stream id
  14 } stream_timing_t;
  15
  16 typedef struct
  17 {
  18     hb_job_t     * job;
  19     hb_title_t   * title;
  20     volatile int * die;
  21
  22     hb_dvd_t     * dvd;
  23     hb_stream_t  * stream;
  24
  25     stream_timing_t *stream_timing;
  26     int64_t        scr_offset;
  27     hb_psdemux_t   demux;
  28     int            scr_changes;
  29     uint           sequence;
  30     int            saw_video;
  31     int            st_slots;            // size (in slots) of stream_timing array
  32 } hb_reader_t;
  33
  34 /***********************************************************************
  35  * Local prototypes
  36  **********************************************************************/
  37 static void        ReaderFunc( void * );
  38 static hb_fifo_t ** GetFifoForId( hb_job_t * job, int id );
  39
  40 /***********************************************************************
  41  * hb_reader_init
  42  ***********************************************************************
  43  *
  44  **********************************************************************/
  45 hb_thread_t * hb_reader_init( hb_job_t * job )
  46 {
  47     hb_reader_t * r;
  48
  49     r = calloc( sizeof( hb_reader_t ), 1 );
  50
  51     r->job   = job;
  52     r->title = job->title;
  53     r->die   = job->die;
  54     r->sequence = 0;
  55
  56     r->st_slots = 4;
  57     r->stream_timing = calloc( sizeof(stream_timing_t), r->st_slots );
  58     r->stream_timing[0].id = r->title->video_id;
  59     r->stream_timing[0].average = 90000. * (double)job->vrate_base /
  60                                            (double)job->vrate;
  61     r->stream_timing[0].last = -r->stream_timing[0].average;
  62     r->stream_timing[1].id = -1;
  63
  64     return hb_thread_init( "reader", ReaderFunc, r,
  65                            HB_NORMAL_PRIORITY );
  66 }
  67
  68 static void push_buf( const hb_reader_t *r, hb_fifo_t *fifo, hb_buffer_t *buf )
  69 {
  70     while( !*r->die && !r->job->done && hb_fifo_is_full( fifo ) )
  71     {
  72         /*
  73          * Loop until the incoming fifo is ready to receive
  74          * this buffer.
  75          */
  76         hb_snooze( 50 );
  77     }
  78     hb_fifo_push( fifo, buf );
  79 }
  80
  81 // The MPEG STD (Standard Target Decoder) essentially requires that we keep
  82 // per-stream timing so that when there's a timing discontinuity we can
  83 // seemlessly join packets on either side of the discontinuity. This join
  84 // requires that we know the timestamp of the previous packet and the
  85 // average inter-packet time (since we position the new packet at the end
  86 // of the previous packet). The next four routines keep track of this
  87 // per-stream timing.
  88
  89 // find the per-stream timing state for 'buf'
  90
  91 static stream_timing_t *find_st( hb_reader_t *r, const hb_buffer_t *buf )
  92 {
  93     stream_timing_t *st = r->stream_timing;
  94     for ( ; st->id != -1; ++st )
  95     {
  96         if ( st->id == buf->id )
  97             return st;
  98     }
  99     return NULL;
 100 }
 101
 102 // find or create the per-stream timing state for 'buf'
 103
 104 static stream_timing_t *id_to_st( hb_reader_t *r, const hb_buffer_t *buf )
 105 {
 106     stream_timing_t *st = r->stream_timing;
 107     while ( st->id != buf->id && st->id != -1)
 108     {
 109         ++st;
 110     }
 111     // if we haven't seen this stream add it.
 112     if ( st->id == -1 )
 113     {
 114         // we keep the steam timing info in an array with some power-of-two
 115         // number of slots. If we don't have two slots left (one for our new
 116         // entry plus one for the "-1" eol) we need to expand the array.
 117         int slot = st - r->stream_timing;
 118         if ( slot + 1 >= r->st_slots )
 119         {
 120             r->st_slots *= 2;
 121             r->stream_timing = realloc( r->stream_timing, r->st_slots *
 122                                         sizeof(*r->stream_timing) );
 123             st = r->stream_timing + slot;
 124         }
 125         st->id = buf->id;
 126         st->average = 30.*90.;
 127         st->last = buf->renderOffset - st->average;
 128
 129         st[1].id = -1;
 130     }
 131     return st;
 132 }
 133
 134 // update the average inter-packet time of the stream associated with 'buf'
 135 // using a recursive low-pass filter with a 16 packet time constant.
 136
 137 static void update_ipt( hb_reader_t *r, const hb_buffer_t *buf )
 138 {
 139     stream_timing_t *st = id_to_st( r, buf );
 140     double dt = buf->renderOffset - st->last;
 141     st->average += ( dt - st->average ) * (1./32.);
 142     st->last = buf->renderOffset;
 143 }
 144
 145 // use the per-stream state associated with 'buf' to compute a new scr_offset
 146 // such that 'buf' will follow the previous packet of this stream separated
 147 // by the average packet time of the stream.
 148
 149 static void new_scr_offset( hb_reader_t *r, hb_buffer_t *buf )
 150 {
 151     stream_timing_t *st = id_to_st( r, buf );
 152     int64_t nxt = st->last + st->average;
 153     r->scr_offset = buf->renderOffset - nxt;
 154     buf->renderOffset = nxt;
 155     r->scr_changes = r->demux.scr_changes;
 156     st->last = buf->renderOffset;
 157 }
 158
 159 /***********************************************************************
 160  * ReaderFunc
 161  ***********************************************************************
 162  *
 163  **********************************************************************/
 164 static void ReaderFunc( void * _r )
 165 {
 166     hb_reader_t  * r = _r;
 167     hb_fifo_t   ** fifos;
 168     hb_buffer_t  * buf;
 169     hb_list_t    * list;
 170     int            n;
 171     int            chapter = -1;
 172     int            chapter_end = r->job->chapter_end;
 173
 174     if( !( r->dvd = hb_dvd_init( r->title->dvd ) ) )
 175     {
 176         if ( !( r->stream = hb_stream_open( r->title->dvd, r->title ) ) )
 177         {
 178           return;
 179         }
 180     }
 181
 182     if (r->dvd)
 183     {
 184         /*
 185          * XXX this code is a temporary hack that should go away if/when
 186          *     chapter merging goes away in libhb/dvd.c
 187          * map the start and end chapter numbers to on-media chapter
 188          * numbers since chapter merging could cause the handbrake numbers
 189          * to diverge from the media numbers and, if our chapter_end is after
 190          * a media chapter that got merged, we'll stop ripping too early.
 191          */
 192         int start = r->job->chapter_start;
 193         hb_chapter_t *chap = hb_list_item( r->title->list_chapter, chapter_end - 1 );
 194
 195         chapter_end = chap->index;
 196         if (start > 1)
 197         {
 198            chap = hb_list_item( r->title->list_chapter, start - 1 );
 199            start = chap->index;
 200         }
 201         /* end chapter mapping XXX */
 202
 203         if( !hb_dvd_start( r->dvd, r->title->index, start ) )
 204         {
 205             hb_dvd_close( &r->dvd );
 206             return;
 207         }
 208
 209         if ( r->job->start_at_preview )
 210         {
 211             // XXX code from DecodePreviews - should go into its own routine
 212             hb_dvd_seek( r->dvd, (float)r->job->start_at_preview /
 213                          ( r->job->seek_points ? ( r->job->seek_points + 1.0 ) : 11.0 ) );
 214         }
 215     }
 216     else if ( r->stream && r->job->start_at_preview )
 217     {
 218
 219         // XXX code from DecodePreviews - should go into its own routine
 220         hb_stream_seek( r->stream, (float)( r->job->start_at_preview - 1 ) /
 221                         ( r->job->seek_points ? ( r->job->seek_points + 1.0 ) : 11.0 ) );
 222
 223     }
 224     else if( r->stream )
 225     {
 226         /*
 227          * Standard stream, seek to the starting chapter, if set, and track the
 228          * end chapter so that we end at the right time.
 229          */
 230         int start = r->job->chapter_start;
 231         hb_chapter_t *chap = hb_list_item( r->title->list_chapter, chapter_end - 1 );
 232
 233         chapter_end = chap->index;
 234         if (start > 1)
 235         {
 236             chap = hb_list_item( r->title->list_chapter, start - 1 );
 237             start = chap->index;
 238         }
 239
 240         /*
 241          * Seek to the start chapter.
 242          */
 243         hb_stream_seek_chapter( r->stream, start );
 244     }
 245
 246     list  = hb_list_init();
 247     hb_buffer_t *ps = hb_buffer_init( HB_DVD_READ_BUFFER_SIZE );
 248
 249     while( !*r->die && !r->job->done )
 250     {
 251         if (r->dvd)
 252             chapter = hb_dvd_chapter( r->dvd );
 253         else if (r->stream)
 254             chapter = hb_stream_chapter( r->stream );
 255
 256         if( chapter < 0 )
 257         {
 258             hb_log( "reader: end of the title reached" );
 259             break;
 260         }
 261         if( chapter > chapter_end )
 262         {
 263             hb_log( "reader: end of chapter %d (media %d) reached at media chapter %d",
 264                     r->job->chapter_end, chapter_end, chapter );
 265             break;
 266         }
 267
 268         if (r->dvd)
 269         {
 270           if( !hb_dvd_read( r->dvd, ps ) )
 271           {
 272               break;
 273           }
 274         }
 275         else if (r->stream)
 276         {
 277           if ( !hb_stream_read( r->stream, ps ) )
 278           {
 279             break;
 280           }
 281         }
 282
 283         if( r->job->indepth_scan )
 284         {
 285             /*
 286              * Need to update the progress during a subtitle scan
 287              */
 288             hb_state_t state;
 289
 290 #define p state.param.working
 291
 292             state.state = HB_STATE_WORKING;
 293             p.progress = (double)chapter / (double)r->job->chapter_end;
 294             if( p.progress > 1.0 )
 295             {
 296                 p.progress = 1.0;
 297             }
 298             p.rate_avg = 0.0;
 299             p.hours    = -1;
 300             p.minutes  = -1;
 301             p.seconds  = -1;
 302             hb_set_state( r->job->h, &state );
 303         }
 304
 305         (hb_demux[r->title->demuxer])( ps, list, &r->demux );
 306
 307         while( ( buf = hb_list_item( list, 0 ) ) )
 308         {
 309             hb_list_rem( list, buf );
 310             fifos = GetFifoForId( r->job, buf->id );
 311
 312             if ( ! r->saw_video )
 313             {
 314                 /* The first video packet defines 'time zero' so discard
 315                    data until we get a video packet with a PTS & DTS */
 316                 if ( buf->id == r->title->video_id && buf->start != -1 &&
 317                      buf->renderOffset != -1 )
 318                 {
 319                     // force a new scr offset computation
 320                     r->scr_changes = r->demux.scr_changes - 1;
 321                     r->saw_video = 1;
 322                     hb_log( "reader: first SCR %lld", r->demux.last_scr );
 323                 }
 324                 else
 325                 {
 326                     fifos = NULL;
 327                 }
 328             }
 329             if( fifos )
 330             {
 331                 if ( buf->renderOffset != -1 )
 332                 {
 333                     if ( r->scr_changes == r->demux.scr_changes )
 334                     {
 335                         // This packet is referenced to the same SCR as the last.
 336                         // Adjust timestamp to remove the System Clock Reference
 337                         // offset then update the average inter-packet time
 338                         // for this stream.
 339                         buf->renderOffset -= r->scr_offset;
 340                         update_ipt( r, buf );
 341                     }
 342                     else
 343                     {
 344                         // This is the first audio or video packet after an SCR
 345                         // change. Compute a new scr offset that would make this
 346                         // packet follow the last of this stream with the correct
 347                         // average spacing.
 348                         stream_timing_t *st = find_st( r, buf );
 349
 350                         if ( st )
 351                         {
 352                             // if this isn't the video stream or we don't
 353                             // have audio yet then generate a new scr
 354                             if ( st != r->stream_timing ||
 355                                  r->stream_timing[1].id == -1 )
 356                             {
 357                                 new_scr_offset( r, buf );
 358                             }
 359                             else
 360                             {
 361                                 // defer the scr change until we get some
 362                                 // audio since audio has a timestamp per
 363                                 // frame but video doesn't. Clear the timestamps
 364                                 // so the decoder will regenerate them from
 365                                 // the frame durations.
 366                                 buf->start = -1;
 367                                 buf->renderOffset = -1;
 368                             }
 369                         }
 370                         else
 371                         {
 372                             // we got a new scr at the same time as the first
 373                             // packet of a stream we've never seen before. We
 374                             // have no idea what the timing should be so toss
 375                             // this buffer & wait for a stream we've already seen.
 376                             hb_buffer_close( &buf );
 377                             continue;
 378                         }
 379                     }
 380                 }
 381                 if ( buf->start != -1 )
 382                 {
 383                     buf->start -= r->scr_offset;
 384                     if ( r->job->pts_to_stop && buf->start > r->job->pts_to_stop )
 385                     {
 386                         // we're doing a subset of the input and we've hit the
 387                         // stopping point.
 388                         hb_buffer_close( &buf );
 389                         goto done;
 390                     }
 391                 }
 392
 393                 buf->sequence = r->sequence++;
 394                 /* if there are mutiple output fifos, send a copy of the
 395                  * buffer down all but the first (we have to not ship the
 396                  * original buffer or we'll race with the thread that's
 397                  * consuming the buffer & inject garbage into the data stream). */
 398                 for( n = 1; fifos[n] != NULL; n++)
 399                 {
 400                     hb_buffer_t *buf_copy = hb_buffer_init( buf->size );
 401                     hb_buffer_copy_settings( buf_copy, buf );
 402                     memcpy( buf_copy->data, buf->data, buf->size );
 403                     push_buf( r, fifos[n], buf_copy );
 404                 }
 405                 push_buf( r, fifos[0], buf );
 406             }
 407             else
 408             {
 409                 hb_buffer_close( &buf );
 410             }
 411         }
 412     }
 413
 414   done:
 415     // send empty buffers downstream to video & audio decoders to signal we're done.
 416     push_buf( r, r->job->fifo_mpeg2, hb_buffer_init(0) );
 417
 418     hb_audio_t *audio;
 419     for( n = 0; ( audio = hb_list_item( r->job->title->list_audio, n ) ); ++n )
 420     {
 421         if ( audio->priv.fifo_in )
 422             push_buf( r, audio->priv.fifo_in, hb_buffer_init(0) );
 423     }
 424
 425     hb_list_empty( &list );
 426     hb_buffer_close( &ps );
 427     if (r->dvd)
 428     {
 429         hb_dvd_stop( r->dvd );
 430         hb_dvd_close( &r->dvd );
 431     }
 432     else if (r->stream)
 433     {
 434         hb_stream_close(&r->stream);
 435     }
 436
 437     if ( r->stream_timing )
 438     {
 439         free( r->stream_timing );
 440     }
 441
 442     hb_log( "reader: done. %d scr changes", r->demux.scr_changes );
 443     if ( r->demux.dts_drops )
 444     {
 445         hb_log( "reader: %d drops because DTS out of range", r->demux.dts_drops );
 446     }
 447
 448     free( r );
 449     _r = NULL;
 450 }
 451
 452 /***********************************************************************
 453  * GetFifoForId
 454  ***********************************************************************
 455  *
 456  **********************************************************************/
 457 static hb_fifo_t ** GetFifoForId( hb_job_t * job, int id )
 458 {
 459     hb_title_t    * title = job->title;
 460     hb_audio_t    * audio;
 461     hb_subtitle_t * subtitle;
 462     int             i, n;
 463     static hb_fifo_t * fifos[8];
 464
 465     memset(fifos, 0, sizeof(fifos));
 466
 467     if( id == title->video_id )
 468     {
 469         if( job->indepth_scan )
 470         {
 471             /*
 472              * Ditch the video here during the indepth scan until
 473              * we can improve the MPEG2 decode performance.
 474              */
 475             return NULL;
 476         }
 477         else
 478         {
 479             fifos[0] = job->fifo_mpeg2;
 480             return fifos;
 481         }
 482     }
 483
 484     if( job->indepth_scan ) {
 485         /*
 486          * Count the occurances of the subtitles, don't actually
 487          * return any to encode unless we are looking fro forced
 488          * subtitles in which case we need to look in the sub picture
 489          * to see if it has the forced flag enabled.
 490          */
 491         for (i=0; i < hb_list_count(title->list_subtitle); i++) {
 492             subtitle =  hb_list_item( title->list_subtitle, i);
 493             if (id == subtitle->id) {
 494                 /*
 495                  * A hit, count it.
 496                  */
 497                 subtitle->hits++;
 498                 if( job->subtitle_force )
 499                 {
 500
 501                     fifos[0] = subtitle->fifo_in;
 502                     return fifos;
 503                 }
 504                 break;
 505             }
 506         }
 507     } else {
 508         if( ( subtitle = hb_list_item( title->list_subtitle, 0 ) ) &&
 509             id == subtitle->id )
 510         {
 511             fifos[0] = subtitle->fifo_in;
 512             return fifos;
 513         }
 514     }
 515     if( !job->indepth_scan )
 516     {
 517         n = 0;
 518         for( i = 0; i < hb_list_count( title->list_audio ); i++ )
 519         {
 520             audio = hb_list_item( title->list_audio, i );
 521             if( id == audio->id )
 522             {
 523                 fifos[n++] = audio->priv.fifo_in;
 524             }
 525         }
 526
 527         if( n != 0 )
 528         {
 529             return fifos;
 530         }
 531     }
 532
 533     return NULL;
 534 }
 535