diff options
Diffstat (limited to 'libhb/reader.c')
| -rw-r--r-- | libhb/reader.c | 144 |
1 files changed, 114 insertions, 30 deletions
diff --git a/libhb/reader.c b/libhb/reader.c index 9ce2a806a..d789993f7 100644 --- a/libhb/reader.c +++ b/libhb/reader.c @@ -8,17 +8,27 @@ typedef struct { + int64_t last; // last timestamp seen on this stream + double average; // average time between packets + int id; // stream id +} stream_timing_t; + +typedef struct +{ hb_job_t * job; hb_title_t * title; volatile int * die; hb_dvd_t * dvd; - hb_buffer_t * ps; hb_stream_t * stream; + stream_timing_t *stream_timing; + int64_t scr_offset; hb_psdemux_t demux; + int scr_changes; uint sequence; int saw_video; + int st_slots; // size (in slots) of stream_timing array } hb_reader_t; /*********************************************************************** @@ -43,26 +53,18 @@ hb_thread_t * hb_reader_init( hb_job_t * job ) r->die = job->die; r->sequence = 0; - /* - * when the scr changes we need to base the timing offset change on the - * end of the current video frame otherwise we'll map the first frame - * following the change over the current frame & it will be discarded. - * Since the PTS only gives the start of the frame we need the average - * frame duration to get its end. See the comments in the init_delay - * setup in libhb/encx264.c to understand the following code. - */ - r->demux.frame_duration = 90000. * (double)job->vrate_base / (double)job->vrate; - if ( r->demux.frame_duration == 3753 ) - { - r->demux.frame_duration = 4506; - } - r->demux.frame_duration += 3; + r->st_slots = 4; + r->stream_timing = calloc( sizeof(stream_timing_t), r->st_slots ); + r->stream_timing[0].id = r->title->video_id; + r->stream_timing[0].average = 90000. * (double)job->vrate_base / + (double)job->vrate; + r->stream_timing[1].id = -1; return hb_thread_init( "reader", ReaderFunc, r, HB_NORMAL_PRIORITY ); } -static void push_buf( hb_reader_t *r, hb_fifo_t *fifo, hb_buffer_t *buf ) +static void push_buf( const hb_reader_t *r, hb_fifo_t *fifo, hb_buffer_t *buf ) { while( !*r->die && !r->job->done && hb_fifo_is_full( fifo ) ) { @@ -75,6 +77,70 @@ static void push_buf( hb_reader_t *r, hb_fifo_t *fifo, hb_buffer_t *buf ) hb_fifo_push( fifo, buf ); } +// The MPEG STD (Standard Timing Decoder) essentially requires that we keep +// per-stream timing so that when there's a timing discontinuity we can +// seemlessly join packets on either side of the discontinuity. This join +// requires that we know the timestamp of the previous packet and the +// average inter-packet time (since we position the new packet at the end +// of the previous packet). The next three routines keep track of this +// per-stream timing. + +// find the per-stream timing state associated with 'buf' + +static stream_timing_t *id_to_st( hb_reader_t *r, const hb_buffer_t *buf ) +{ + stream_timing_t *st = r->stream_timing; + while ( st->id != buf->id && st->id != -1) + { + ++st; + } + // if we haven't seen this stream add it. + if ( st->id == -1 ) + { + // we keep the steam timing info in an array with some power-of-two + // number of slots. If we don't have two slots left (one for our new + // entry plus one for the "-1" eol) we need to expand the array. + int slot = st - r->stream_timing; + if ( slot + 1 >= r->st_slots ) + { + r->st_slots *= 2; + r->stream_timing = realloc( r->stream_timing, r->st_slots * + sizeof(*r->stream_timing) ); + st = r->stream_timing + slot; + } + st->id = buf->id; + st->last = buf->renderOffset; + st->average = 30.*90.; + + st[1].id = -1; + } + return st; +} + +// update the average inter-packet time of the stream associated with 'buf' +// using a recursive low-pass filter with a 16 packet time constant. + +static void update_ipt( hb_reader_t *r, const hb_buffer_t *buf ) +{ + stream_timing_t *st = id_to_st( r, buf ); + double dt = buf->renderOffset - st->last; + st->average += ( dt - st->average ) * (1./16.); + st->last = buf->renderOffset; +} + +// use the per-stream state associated with 'buf' to compute a new scr_offset +// such that 'buf' will follow the previous packet of this stream separated +// by the average packet time of the stream. + +static void new_scr_offset( hb_reader_t *r, const hb_buffer_t *buf ) +{ + stream_timing_t *st = id_to_st( r, buf ); + int64_t nxt = st->last + st->average - r->scr_offset; + r->scr_offset = buf->renderOffset - nxt; + r->scr_changes = r->demux.scr_changes; + st->last = buf->renderOffset; +} + /*********************************************************************** * ReaderFunc *********************************************************************** @@ -127,7 +193,7 @@ static void ReaderFunc( void * _r ) } list = hb_list_init(); - r->ps = hb_buffer_init( HB_DVD_READ_BUFFER_SIZE ); + hb_buffer_t *ps = hb_buffer_init( HB_DVD_READ_BUFFER_SIZE ); while( !*r->die && !r->job->done ) { @@ -150,14 +216,14 @@ static void ReaderFunc( void * _r ) if (r->dvd) { - if( !hb_dvd_read( r->dvd, r->ps ) ) + if( !hb_dvd_read( r->dvd, ps ) ) { break; } } else if (r->stream) { - if ( !hb_stream_read( r->stream, r->ps ) ) + if ( !hb_stream_read( r->stream, ps ) ) { break; } @@ -187,11 +253,11 @@ static void ReaderFunc( void * _r ) if ( r->title->demuxer == HB_NULL_DEMUXER ) { - hb_demux_null( r->ps, list, &r->demux ); + hb_demux_null( ps, list, &r->demux ); } else { - hb_demux_ps( r->ps, list, &r->demux ); + hb_demux_ps( ps, list, &r->demux ); } while( ( buf = hb_list_item( list, 0 ) ) ) @@ -206,9 +272,10 @@ static void ReaderFunc( void * _r ) if ( buf->id == r->title->video_id && buf->start != -1 ) { r->saw_video = 1; - r->demux.scr_offset = buf->renderOffset; + r->scr_changes = r->demux.scr_changes; + new_scr_offset( r, buf ); hb_log( "reader: first SCR %llu scr_offset %llu", - r->demux.last_scr, r->demux.scr_offset ); + r->demux.last_scr, r->scr_offset ); } else { @@ -219,13 +286,25 @@ static void ReaderFunc( void * _r ) { if ( buf->start != -1 ) { - /* this packet has a PTS - correct it for the initial - video time offset & any timing discontinuities so that - everything after this sees a continuous clock with 0 - being the time of the first video packet. */ - buf->start -= r->demux.scr_offset; - buf->renderOffset -= r->demux.scr_offset; + if ( r->scr_changes == r->demux.scr_changes ) + { + // This packet is referenced to the same SCR as the last. + // Update the average inter-packet time for this stream. + update_ipt( r, buf ); + } + else + { + // This is the first audio or video packet after an SCR + // change. Compute a new scr offset that would make this + // packet follow the last of this stream with the correct + // average spacing. + new_scr_offset( r, buf ); + } + // adjust timestamps to remove System Clock Reference offsets. + buf->start -= r->scr_offset; + buf->renderOffset -= r->scr_offset; } + buf->sequence = r->sequence++; /* if there are mutiple output fifos, send a copy of the * buffer down all but the first (we have to not ship the @@ -251,7 +330,7 @@ static void ReaderFunc( void * _r ) hb_fifo_push( r->job->fifo_mpeg2, hb_buffer_init(0) ); hb_list_empty( &list ); - hb_buffer_close( &r->ps ); + hb_buffer_close( &ps ); if (r->dvd) { hb_dvd_stop( r->dvd ); @@ -262,6 +341,11 @@ static void ReaderFunc( void * _r ) hb_stream_close(&r->stream); } + if ( r->stream_timing ) + { + free( r->stream_timing ); + } + hb_log( "reader: done. %d scr changes", r->demux.scr_changes ); free( r ); |