From 56d9caaefb91abc763be3a1d17d14d0e7e2e9059 Mon Sep 17 00:00:00 2001 From: van Date: Tue, 15 Apr 2008 19:14:03 +0000 Subject: Move clock recovery code from reader to demuxmpeg so it sees all frames & not just the ones we happen to be encoding. This change gives a more accurate clock and allows us to once again ignore audio during pass 1 of a 2 pass encode. git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@1420 b64f7644-9d1e-0410-96f1-a4d463321fa5 --- libhb/demuxmpeg.c | 56 ++++++++++++++++++++++++++++++++++++++++---------- libhb/hb.c | 6 +----- libhb/internal.h | 8 +++++++- libhb/reader.c | 61 ++++++++----------------------------------------------- libhb/scan.c | 2 +- libhb/stream.c | 4 ++-- 6 files changed, 65 insertions(+), 72 deletions(-) (limited to 'libhb') diff --git a/libhb/demuxmpeg.c b/libhb/demuxmpeg.c index 424cce696..35d941ad0 100644 --- a/libhb/demuxmpeg.c +++ b/libhb/demuxmpeg.c @@ -8,11 +8,10 @@ /* Basic MPEG demuxer, only works with DVDs (2048 bytes packets) */ -int hb_demux_ps( hb_buffer_t * buf_ps, hb_list_t * list_es ) +int hb_demux_ps( hb_buffer_t * buf_ps, hb_list_t * list_es, hb_psdemux_t* state ) { hb_buffer_t * buf_es; int pos = 0; - int64_t scr; #define d (buf_ps->data) @@ -25,14 +24,49 @@ int hb_demux_ps( hb_buffer_t * buf_ps, hb_list_t * list_es ) return 0; } pos += 4; /* pack_start_code */ - /* extract the system clock reference (scr) */ - scr = ((uint64_t)(d[pos] & 0x38) << 27) | - ((uint64_t)(d[pos] & 0x03) << 28) | - ((uint64_t)(d[pos+1]) << 20) | - ((uint64_t)(d[pos+2] >> 3) << 15) | - ((uint64_t)(d[pos+2] & 3) << 13) | - ((uint64_t)(d[pos+3]) << 5) | - (d[pos+4] >> 3); + + if ( state ) + { + /* + * This section of code implements the timing model of + * the "Standard Target Decoder" (STD) of the MPEG2 standard + * (specified in ISO 13818-1 sections 2.4.2, 2.5.2 & Annex D). + * The STD removes and corrects for clock discontinuities so + * that the time stamps on the video, audio & other media + * streams can be used for cross-media synchronization. To do + * this the STD has its own timestamp value, the System Clock + * Reference or SCR, in the PACK header. Clock discontinuities + * are detected using the SCR & and the adjustment needed + * to correct post-discontinuity timestamps to be contiguous + * with pre-discontinuity timestamps is computed from pre- and + * post-discontinuity values of the SCR. Then this adjustment + * is applied to every media timestamp (PTS). + * + * ISO 13818-1 says there must be an SCR at least every 700ms + * (100ms for Transport Streams) so if the difference between + * this SCR & the previous is >700ms it's a discontinuity. + * If the difference is negative it's non-physical (time doesn't + * go backward) and must also be a discontinuity. When we find a + * discontinuity we adjust the scr_offset so that the SCR of the + * new packet lines up with that of the previous packet. + */ + /* extract the system clock reference (scr) */ + int64_t scr = ((uint64_t)(d[pos] & 0x38) << 27) | + ((uint64_t)(d[pos] & 0x03) << 28) | + ((uint64_t)(d[pos+1]) << 20) | + ((uint64_t)(d[pos+2] >> 3) << 15) | + ((uint64_t)(d[pos+2] & 3) << 13) | + ((uint64_t)(d[pos+3]) << 5) | + (d[pos+4] >> 3); + int64_t scr_delta = scr - state->last_scr; + if ( scr_delta > (90*700) || scr_delta < 0 ) + { + ++state->scr_changes; + state->scr_offset += scr_delta - 1; + } + state->last_scr = scr; + } + pos += 9; /* pack_header */ pos += 1 + ( d[pos] & 0x7 ); /* stuffing bytes */ @@ -119,7 +153,7 @@ int hb_demux_ps( hb_buffer_t * buf_ps, hb_list_t * list_es ) buf_es->id = id; buf_es->start = pts; - buf_es->stop = scr; + buf_es->stop = -1; if (id == 0xE0) { // Consume a chapter break, and apply it to the ES. buf_es->new_chap = buf_ps->new_chap; diff --git a/libhb/hb.c b/libhb/hb.c index a6fc87fca..5f176f1ae 100644 --- a/libhb/hb.c +++ b/libhb/hb.c @@ -857,11 +857,7 @@ void hb_add( hb_handle_t * h, hb_job_t * job ) title_copy->list_audio = hb_list_init(); /* Do nothing about audio during first pass */ - // XXX for right now we need to see the audio in libhb/reader.c to track - // clock changes otherwise we'll discard more video frames in pass 1 than - // pass 2 & screw up the encoding. Once the clock tracking is moved from - // reader to the mpeg demuxer this code can be restored. - //if( job->pass == 0 || job->pass == 2 ) + if( job->pass == 0 || job->pass == 2 ) { for( i = 0; i < hb_list_count(job->list_audio); i++ ) { diff --git a/libhb/internal.h b/libhb/internal.h index 73a5502da..5f3baecc5 100644 --- a/libhb/internal.h +++ b/libhb/internal.h @@ -117,7 +117,13 @@ int hb_libmpeg2_clear_aspect_ratio( hb_libmpeg2_t * ); /*********************************************************************** * mpegdemux.c **********************************************************************/ -int hb_demux_ps( hb_buffer_t * ps_buf, hb_list_t * es_list ); +typedef struct { + int64_t last_scr; /* unadjusted SCR from most recent pack */ + int64_t scr_offset; /* discontinuity correction adjustment */ + int scr_changes; /* number of SCR discontinuities */ +} hb_psdemux_t; + +int hb_demux_ps( hb_buffer_t * ps_buf, hb_list_t * es_list, hb_psdemux_t * ); /*********************************************************************** * dvd.c diff --git a/libhb/reader.c b/libhb/reader.c index ac02f90ca..233319833 100644 --- a/libhb/reader.c +++ b/libhb/reader.c @@ -16,12 +16,9 @@ typedef struct hb_buffer_t * ps; hb_stream_t * stream; + hb_psdemux_t demux; uint sequence; int saw_video; - int64_t scr_offset; - int64_t last_scr; - int scr_changes; - } hb_reader_t; /*********************************************************************** @@ -161,7 +158,7 @@ static void ReaderFunc( void * _r ) hb_set_state( r->job->h, &state ); } - hb_demux_ps( r->ps, list ); + hb_demux_ps( r->ps, list, &r->demux ); while( ( buf = hb_list_item( list, 0 ) ) ) { @@ -175,10 +172,9 @@ static void ReaderFunc( void * _r ) if ( buf->id == 0xE0 && buf->start != -1 ) { r->saw_video = 1; - r->scr_offset = buf->start; - r->last_scr = buf->stop; + r->demux.scr_offset = buf->start; hb_log( "reader: first SCR %llu scr_offset %llu", - r->last_scr, r->scr_offset ); + r->demux.last_scr, r->demux.scr_offset ); } else { @@ -187,52 +183,13 @@ static void ReaderFunc( void * _r ) } if( fifos ) { - /* - * This section of code implements the timing model of - * the "Standard Target Decoder" (STD) of the MPEG2 standard - * (specified in ISO 13818-1 sections 2.4.2, 2.5.2 & Annex D). - * The STD removes and corrects for clock discontinuities so - * that the time stamps on the video, audio & other media - * streams can be used for cross-media synchronization. To do - * this the STD has its own timestamp value, the System Clock - * Reference or SCR, in the PACK header. Clock discontinuities - * are detected using the SCR & and the adjustment needed - * to correct post-discontinuity timestamps to be contiguous - * with pre-discontinuity timestamps is computed from pre- and - * post-discontinuity values of the SCR. Then this adjustment - * is applied to every media timestamp (PTS). - * - * hb_demux_ps left the SCR for this pack in buf->stop. - * ISO 13818-1 says there must be an SCR at least every 700ms - * (100ms for Transport Streams) so if the difference between - * this SCR & the previous is >700ms it's a discontinuity. - * If the difference is negative it's non-physical (time doesn't - * go backward) and must also be a discontinuity. When we find a - * discontinuity we adjust the scr_offset so that the SCR of the - * new packet lines up with that of the previous packet. - */ - int64_t scr_delta = buf->stop - r->last_scr; - if ( scr_delta > (90*700) || scr_delta < -90 ) - { - ++r->scr_changes; - r->scr_offset += scr_delta - 1; - } - r->last_scr = buf->stop; - buf->stop = -1; - - /* - * The last section detected discontinuites and computed the - * appropriate correction to remove them. The next couple of - * lines apply the correction to the media timestamps so the - * code downstream of us sees only timestamps relative to the - * same, continuous clock with time zero on that clock being - * the time of the first video packet. - */ if ( buf->start != -1 ) { /* this packet has a PTS - correct it for the initial - video time offset & any timing discontinuities. */ - buf->start -= r->scr_offset; + 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->sequence = r->sequence++; for( n = 0; fifos[n] != NULL; n++) @@ -284,7 +241,7 @@ static void ReaderFunc( void * _r ) hb_stream_close(&r->stream); } - hb_log( "reader: done. %d scr changes", r->scr_changes ); + hb_log( "reader: done. %d scr changes", r->demux.scr_changes ); free( r ); _r = NULL; diff --git a/libhb/scan.c b/libhb/scan.c index 8669fb01e..b139e5e4c 100644 --- a/libhb/scan.c +++ b/libhb/scan.c @@ -299,7 +299,7 @@ static int DecodePreviews( hb_scan_t * data, hb_title_t * title ) goto skip_preview; } } - hb_demux_ps( buf_ps, list_es ); + hb_demux_ps( buf_ps, list_es, 0 ); while( ( buf_es = hb_list_item( list_es, 0 ) ) ) { diff --git a/libhb/stream.c b/libhb/stream.c index 9738eb36b..1d1ea2b26 100755 --- a/libhb/stream.c +++ b/libhb/stream.c @@ -541,7 +541,7 @@ static uint64_t hb_ps_stream_getVideoPTS(hb_stream_t *stream) hb_buffer_t *es; // 'buf' contains an MPEG2 PACK - get a list of all it's elementary streams - hb_demux_ps(buf, list); + hb_demux_ps(buf, list, 0); while ( ( es = hb_list_item( list, 0 ) ) ) { @@ -884,7 +884,7 @@ static void hb_ps_stream_find_audio_ids(hb_stream_t *stream, hb_title_t *title) hb_buffer_t *es; // 'buf' contains an MPEG2 PACK - get a list of all it's elementary streams - hb_demux_ps(buf, list); + hb_demux_ps(buf, list, 0); while ( ( es = hb_list_item( list, 0 ) ) ) { -- cgit v1.2.3