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
 210     list  = hb_list_init();
 211     hb_buffer_t *ps = hb_buffer_init( HB_DVD_READ_BUFFER_SIZE );
 212     r->demux.flaky_clock = r->title->flaky_clock;
 213
 214     while( !*r->die && !r->job->done )
 215     {
 216         if (r->dvd)
 217           chapter = hb_dvd_chapter( r->dvd );
 218         else if (r->stream)
 219           chapter = 1;
 220
 221         if( chapter < 0 )
 222         {
 223             hb_log( "reader: end of the title reached" );
 224             break;
 225         }
 226         if( chapter > chapter_end )
 227         {
 228             hb_log( "reader: end of chapter %d (media %d) reached at media chapter %d",
 229                     r->job->chapter_end, chapter_end, chapter );
 230             break;
 231         }
 232
 233         if (r->dvd)
 234         {
 235           if( !hb_dvd_read( r->dvd, ps ) )
 236           {
 237               break;
 238           }
 239         }
 240         else if (r->stream)
 241         {
 242           if ( !hb_stream_read( r->stream, ps ) )
 243           {
 244             break;
 245           }
 246         }
 247
 248         if( r->job->indepth_scan )
 249         {
 250             /*
 251              * Need to update the progress during a subtitle scan
 252              */
 253             hb_state_t state;
 254
 255 #define p state.param.working
 256
 257             state.state = HB_STATE_WORKING;
 258             p.progress = (double)chapter / (double)r->job->chapter_end;
 259             if( p.progress > 1.0 )
 260             {
 261                 p.progress = 1.0;
 262             }
 263             p.rate_avg = 0.0;
 264             p.hours    = -1;
 265             p.minutes  = -1;
 266             p.seconds  = -1;
 267             hb_set_state( r->job->h, &state );
 268         }
 269
 270         if ( r->title->demuxer == HB_NULL_DEMUXER )
 271         {
 272             hb_demux_null( ps, list, &r->demux );
 273         }
 274         else
 275         {
 276             hb_demux_ps( ps, list, &r->demux );
 277         }
 278
 279         while( ( buf = hb_list_item( list, 0 ) ) )
 280         {
 281             hb_list_rem( list, buf );
 282             fifos = GetFifoForId( r->job, buf->id );
 283
 284             if ( ! r->saw_video )
 285             {
 286                 /* The first video packet defines 'time zero' so discard
 287                    data until we get a video packet with a PTS & DTS */
 288                 if ( buf->id == r->title->video_id && buf->start != -1 &&
 289                      buf->renderOffset != -1 )
 290                 {
 291                     // force a new scr offset computation
 292                     r->scr_changes = r->demux.scr_changes - 1;
 293                     r->saw_video = 1;
 294                     hb_log( "reader: first SCR %lld", r->demux.last_scr );
 295                 }
 296                 else
 297                 {
 298                     fifos = NULL;
 299                 }
 300             }
 301             if( fifos )
 302             {
 303                 if ( buf->renderOffset != -1 )
 304                 {
 305                     if ( r->scr_changes == r->demux.scr_changes )
 306                     {
 307                         // This packet is referenced to the same SCR as the last.
 308                         // Adjust timestamp to remove the System Clock Reference
 309                         // offset then update the average inter-packet time
 310                         // for this stream.
 311                         buf->renderOffset -= r->scr_offset;
 312                         update_ipt( r, buf );
 313                     }
 314                     else
 315                     {
 316                         // This is the first audio or video packet after an SCR
 317                         // change. Compute a new scr offset that would make this
 318                         // packet follow the last of this stream with the correct
 319                         // average spacing.
 320                         stream_timing_t *st = find_st( r, buf );
 321
 322                         if ( st )
 323                         {
 324                             // if this isn't the video stream or we don't
 325                             // have audio yet then generate a new scr
 326                             if ( st != r->stream_timing ||
 327                                  r->stream_timing[1].id == -1 )
 328                             {
 329                                 new_scr_offset( r, buf );
 330                             }
 331                             else
 332                             {
 333                                 // defer the scr change until we get some
 334                                 // audio since audio has a timestamp per
 335                                 // frame but video doesn't. Clear the timestamps
 336                                 // so the decoder will regenerate them from
 337                                 // the frame durations.
 338                                 buf->start = -1;
 339                                 buf->renderOffset = -1;
 340                             }
 341                         }
 342                         else
 343                         {
 344                             // we got a new scr at the same time as the first
 345                             // packet of a stream we've never seen before. We
 346                             // have no idea what the timing should be so toss
 347                             // this buffer & wait for a stream we've already seen.
 348                             hb_buffer_close( &buf );
 349                             continue;
 350                         }
 351                     }
 352                 }
 353                 if ( buf->start != -1 )
 354                     buf->start -= r->scr_offset;
 355
 356                 buf->sequence = r->sequence++;
 357                 /* if there are mutiple output fifos, send a copy of the
 358                  * buffer down all but the first (we have to not ship the
 359                  * original buffer or we'll race with the thread that's
 360                  * consuming the buffer & inject garbage into the data stream). */
 361                 for( n = 1; fifos[n] != NULL; n++)
 362                 {
 363                     hb_buffer_t *buf_copy = hb_buffer_init( buf->size );
 364                     hb_buffer_copy_settings( buf_copy, buf );
 365                     memcpy( buf_copy->data, buf->data, buf->size );
 366                     push_buf( r, fifos[n], buf_copy );
 367                 }
 368                 push_buf( r, fifos[0], buf );
 369             }
 370             else
 371             {
 372                 hb_buffer_close( &buf );
 373             }
 374         }
 375     }
 376
 377     // send empty buffers downstream to video & audio decoders to signal we're done.
 378     push_buf( r, r->job->fifo_mpeg2, hb_buffer_init(0) );
 379
 380     hb_audio_t *audio;
 381     for( n = 0; ( audio = hb_list_item( r->job->title->list_audio, n ) ); ++n )
 382     {
 383         if ( audio->priv.fifo_in )
 384             push_buf( r, audio->priv.fifo_in, hb_buffer_init(0) );
 385     }
 386
 387     hb_list_empty( &list );
 388     hb_buffer_close( &ps );
 389     if (r->dvd)
 390     {
 391         hb_dvd_stop( r->dvd );
 392         hb_dvd_close( &r->dvd );
 393     }
 394     else if (r->stream)
 395     {
 396         hb_stream_close(&r->stream);
 397     }
 398
 399     if ( r->stream_timing )
 400     {
 401         free( r->stream_timing );
 402     }
 403
 404     hb_log( "reader: done. %d scr changes", r->demux.scr_changes );
 405     if ( r->demux.dts_drops )
 406     {
 407         hb_log( "reader: %d drops because DTS out of range", r->demux.dts_drops );
 408     }
 409
 410     free( r );
 411     _r = NULL;
 412 }
 413
 414 /***********************************************************************
 415  * GetFifoForId
 416  ***********************************************************************
 417  *
 418  **********************************************************************/
 419 static hb_fifo_t ** GetFifoForId( hb_job_t * job, int id )
 420 {
 421     hb_title_t    * title = job->title;
 422     hb_audio_t    * audio;
 423     hb_subtitle_t * subtitle;
 424     int             i, n;
 425     static hb_fifo_t * fifos[8];
 426
 427     memset(fifos, 0, sizeof(fifos));
 428
 429     if( id == title->video_id )
 430     {
 431         if( job->indepth_scan )
 432         {
 433             /*
 434              * Ditch the video here during the indepth scan until
 435              * we can improve the MPEG2 decode performance.
 436              */
 437             return NULL;
 438         }
 439         else
 440         {
 441             fifos[0] = job->fifo_mpeg2;
 442             return fifos;
 443         }
 444     }
 445
 446     if( job->indepth_scan ) {
 447         /*
 448          * Count the occurances of the subtitles, don't actually
 449          * return any to encode unless we are looking fro forced
 450          * subtitles in which case we need to look in the sub picture
 451          * to see if it has the forced flag enabled.
 452          */
 453         for (i=0; i < hb_list_count(title->list_subtitle); i++) {
 454             subtitle =  hb_list_item( title->list_subtitle, i);
 455             if (id == subtitle->id) {
 456                 /*
 457                  * A hit, count it.
 458                  */
 459                 subtitle->hits++;
 460                 if( job->subtitle_force )
 461                 {
 462
 463                     fifos[0] = subtitle->fifo_in;
 464                     return fifos;
 465                 }
 466                 break;
 467             }
 468         }
 469     } else {
 470         if( ( subtitle = hb_list_item( title->list_subtitle, 0 ) ) &&
 471             id == subtitle->id )
 472         {
 473             fifos[0] = subtitle->fifo_in;
 474             return fifos;
 475         }
 476     }
 477     if( !job->indepth_scan )
 478     {
 479         n = 0;
 480         for( i = 0; i < hb_list_count( title->list_audio ); i++ )
 481         {
 482             audio = hb_list_item( title->list_audio, i );
 483             if( id == audio->id )
 484             {
 485                 fifos[n++] = audio->priv.fifo_in;
 486             }
 487         }
 488
 489         if( n != 0 )
 490         {
 491             return fifos;
 492         }
 493     }
 494
 495     return NULL;
 496 }
 497