/* $Id: reader.c,v 1.21 2005/11/25 15:05:25 titer Exp $
This file is part of the HandBrake source code.
- Homepage: <http://handbrake.m0k.org/>.
+ Homepage: <http://handbrake.fr/>.
It may be used under the terms of the GNU General Public License. */
#include "hb.h"
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;
- uint sequence;
- int saw_video;
+ stream_timing_t *stream_timing;
int64_t scr_offset;
- int64_t last_scr;
+ 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;
/***********************************************************************
r->die = job->die;
r->sequence = 0;
+ 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( const hb_reader_t *r, hb_fifo_t *fifo, hb_buffer_t *buf )
+{
+ while( !*r->die && !r->job->done && hb_fifo_is_full( fifo ) )
+ {
+ /*
+ * Loop until the incoming fifo is ready to receive
+ * this buffer.
+ */
+ hb_snooze( 50 );
+ }
+ 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
***********************************************************************
hb_reader_t * r = _r;
hb_fifo_t ** fifos;
hb_buffer_t * buf;
- hb_buffer_t * buf_old;
hb_list_t * list;
int n;
int chapter = -1;
if( !( r->dvd = hb_dvd_init( r->title->dvd ) ) )
{
- if ( !( r->stream = hb_stream_open( r->title->dvd, 1 ) ) )
+ if ( !( r->stream = hb_stream_open( r->title->dvd, r->title ) ) )
{
return;
}
}
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 )
{
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;
}
#define p state.param.working
state.state = HB_STATE_WORKING;
- p.progress = (float)chapter / (float)r->job->chapter_end;
+ p.progress = (double)chapter / (double)r->job->chapter_end;
if( p.progress > 1.0 )
{
p.progress = 1.0;
hb_set_state( r->job->h, &state );
}
- hb_demux_ps( r->ps, list );
+ if ( r->title->demuxer == HB_NULL_DEMUXER )
+ {
+ hb_demux_null( ps, list, &r->demux );
+ }
+ else
+ {
+ hb_demux_ps( ps, list, &r->demux );
+ }
while( ( buf = hb_list_item( list, 0 ) ) )
{
{
/* The first video packet defines 'time zero' so discard
data until we get a video packet with a PTS */
- if ( buf->id == 0xE0 && buf->start != -1 )
+ if ( buf->id == r->title->video_id && buf->start != -1 )
{
r->saw_video = 1;
- r->scr_offset = buf->start;
- r->last_scr = buf->stop;
+ r->scr_changes = r->demux.scr_changes;
+ new_scr_offset( r, buf );
hb_log( "reader: first SCR %llu scr_offset %llu",
- r->last_scr, r->scr_offset );
+ r->demux.last_scr, r->scr_offset );
}
else
{
}
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;
- }
- buf->sequence = r->sequence++;
- for( n = 0; fifos[n] != NULL; n++)
- {
- if( n != 0 )
+ if ( r->scr_changes == r->demux.scr_changes )
{
- /*
- * Replace the buffer with a new copy of itself for when
- * it is being sent down multiple fifos.
- */
- buf_old = buf;
- buf = hb_buffer_init(buf_old->size);
- memcpy( buf->data, buf_old->data, buf->size );
- hb_buffer_copy_settings( buf, buf_old );
+ // This packet is referenced to the same SCR as the last.
+ // Update the average inter-packet time for this stream.
+ update_ipt( r, buf );
}
-
- while( !*r->die && !r->job->done &&
- hb_fifo_is_full( fifos[n] ) )
+ else
{
- /*
- * Loop until the incoming fifo is reaqdy to receive
- * this buffer.
- */
- hb_snooze( 50 );
+ // 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;
+ }
- hb_fifo_push( fifos[n], buf );
+ 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
+ * original buffer or we'll race with the thread that's
+ * consuming the buffer & inject garbage into the data stream). */
+ for( n = 1; fifos[n] != NULL; n++)
+ {
+ hb_buffer_t *buf_copy = hb_buffer_init( buf->size );
+ hb_buffer_copy_settings( buf_copy, buf );
+ memcpy( buf_copy->data, buf->data, buf->size );
+ push_buf( r, fifos[n], buf_copy );
}
+ push_buf( r, fifos[0], buf );
}
else
{
}
}
- /* send an empty buffer upstream to signal we're done */
- hb_fifo_push( r->job->fifo_mpeg2, hb_buffer_init(0) );
+ /* send empty buffers upstream to video & audio decoders to signal we're done */
+ push_buf( r, r->job->fifo_mpeg2, hb_buffer_init(0) );
+
+ hb_audio_t *audio;
+ for( n = 0;
+ ( audio = hb_list_item( r->job->title->list_audio, n ) ) != NULL;
+ ++n )
+ {
+ push_buf( r, audio->priv.fifo_in, 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 );
hb_stream_close(&r->stream);
}
- hb_log( "reader: done. %d scr changes", r->scr_changes );
+ if ( r->stream_timing )
+ {
+ free( r->stream_timing );
+ }
+
+ hb_log( "reader: done. %d scr changes", r->demux.scr_changes );
free( r );
_r = NULL;
memset(fifos, 0, sizeof(fifos));
- if( id == 0xE0 )
+ if( id == title->video_id )
{
if( job->indepth_scan )
{
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