uint8_t *x264_allocated_pic;
int chap_mark; // saved chap mark when we're propagating it
- int64_t dts_next; // DTS start time value for next output frame
int64_t last_stop; // Debugging - stop time of previous input frame
int64_t init_delay;
- int64_t max_delay; // if init_delay too small, delay really needed
int64_t next_chap;
struct {
pv->x264_allocated_pic = pv->pic_in.img.plane[0];
- pv->dts_next = -1;
- pv->next_chap = 0;
-
if (job->areBframes)
{
/* Basic initDelay value is the clockrate divided by the FPS
/* The delay is 1 frames for regular b-frames, 2 for b-pyramid. */
pv->init_delay *= job->areBframes;
}
+ w->config->h264.init_delay = pv->init_delay;
return 0;
}
hb_work_private_t *pv = w->private_data;
hb_job_t *job = pv->job;
- /* Get next DTS value to use */
- int64_t dts_start = pv->dts_next;
-
- /* compute the stop time based on the original frame's duration */
- int64_t dts_stop = dts_start + get_frame_duration( pv, pic_out->i_pts );
- pv->dts_next = dts_stop;
-
/* Should be way too large */
buf = hb_buffer_init( 3 * job->width * job->height / 2 );
buf->size = 0;
buf->frametype = 0;
- buf->start = dts_start;
- buf->stop = dts_stop;
- /* Store the output presentation time stamp from x264 for use by muxmp4
- in off-setting b-frames with the CTTS atom. */
- buf->renderOffset = pic_out->i_pts - dts_start + pv->init_delay;
- if ( buf->renderOffset < 0 )
- {
- if ( dts_start - pic_out->i_pts > pv->max_delay )
- {
- pv->max_delay = dts_start - pic_out->i_pts;
- hb_log( "encx264: init_delay too small: "
- "is %lld need %lld", pv->init_delay,
- pv->max_delay );
- }
- buf->renderOffset = 0;
- }
+ // use the pts to get the original frame's duration.
+ int64_t duration = get_frame_duration( pv, pic_out->i_pts );
+ buf->start = pic_out->i_pts;
+ buf->stop = pic_out->i_pts + duration;
/* Encode all the NALs we were given into buf.
NOTE: This code assumes one video frame per NAL (but there can
// make sure we found at least one video frame
if ( buf->size <= 0 )
{
- // no video: back up the output time stamp then free the buf
- pv->dts_next = buf->start;
+ // no video - discard the buf
hb_buffer_close( &buf );
}
return buf;
pv->pic_in.img.plane[1] = in->data + job->width * job->height;
pv->pic_in.img.plane[2] = in->data + 5 * job->width * job->height / 4;
}
-
- if( pv->dts_next == -1 )
- {
- /* we don't have a start time yet so use the first frame's
- * start. All other frame times will be determined by the
- * sum of the prior output frame durations in *DTS* order
- * (not by the order they arrive here). This timing change is
- * essential for VFR with b-frames but a complete nop otherwise.
- */
- pv->dts_next = in->start;
- }
if( in->new_chap && job->chapter_markers )
{
/* chapters have to start with an IDR frame so request that this
// the x264_encoder_encode call (since it reorders frames).
save_frame_info( pv, in );
- /* Feed the input DTS to x264 so it can figure out proper output PTS */
+ /* Feed the input PTS to x264 so it can figure out proper output PTS */
pv->pic_in.i_pts = in->start;
x264_picture_t pic_out;
}
// Not EOF - encode the packet & wrap it in a NAL
+
+ // if we're re-ordering frames, check if this frame is too large to reorder
if ( pv->init_delay && in->stop - in->start > pv->init_delay )
{
// This frame's duration is larger than the time allotted for b-frame
/* libmp4v2 handle */
MP4FileHandle file;
- /* Cumulated durations so far, in timescale units (see MP4Mux) */
- uint64_t sum_dur;
+ /* Cumulated durations so far, in output & input timescale units (see MP4Mux) */
+ int64_t sum_dur; // duration in output timescale units
+ int64_t sum_dur_in; // duration in input 90KHz timescale units
+
+ // bias to keep render offsets in ctts atom positive (set up by encx264)
+ int64_t init_delay;
/* Chapter state information for muxing */
MP4TrackId chapter_track;
AddIPodUUID(m->file, mux_data->track);
}
+ m->init_delay = job->config.h264.init_delay;
}
else /* FFmpeg or XviD */
{
hb_buffer_t * buf )
{
hb_job_t * job = m->job;
-
int64_t duration;
+ int64_t offset = 0;
if( mux_data == job->mux_data )
{
+ /* Video */
+
+ // if there are b-frames compute the render offset
+ // (we'll need it for both the video frame & the chapter track)
+ if ( m->init_delay )
+ {
+ offset = ( buf->start + m->init_delay ) * m->samplerate / 90000 -
+ m->sum_dur;
+ }
/* Add the sample before the new frame.
It is important that this be calculated prior to the duration
of the new video sample, as we want to sync to right after it.
{
struct hb_text_sample_s *sample;
- /* If this is an x264 encode with bframes the IDR frame we're
- trying to mark will be displayed offset by its renderOffset
- so we need to offset the chapter by the same amount.
- MP4 render offsets don't seem to work for text tracks so
- we have to fudge the duration instead. */
- duration = m->sum_dur - m->chapter_duration;
-
- if ( job->areBframes )
- {
- duration += buf->renderOffset * m->samplerate / 90000;
- }
+ // this chapter is postioned by writing out the previous chapter.
+ // the duration of the previous chapter is the duration up to but
+ // not including the current frame minus the duration of all
+ // chapters up to the previous.
+ duration = m->sum_dur - m->chapter_duration + offset;
if ( duration <= 0 )
{
/* The initial & final chapters can have very short durations
m->chapter_duration += duration;
}
- /* Video */
- /* Because we use the audio samplerate as the timescale,
- we have to use potentially variable durations so the video
- doesn't go out of sync */
- int64_t bias = ( buf->start * m->samplerate / 90000 ) - m->sum_dur;
- duration = ( buf->stop - buf->start ) * m->samplerate / 90000 + bias;
+ // since we're changing the sample rate we need to keep track of
+ // the truncation bias so that the audio and video don't go out
+ // of sync. m->sum_dur_in is the sum of the input durations so far.
+ // m->sum_dur is the sum of the output durations. Their difference
+ // (in output sample rate units) is the accumulated truncation bias.
+ int64_t bias = ( m->sum_dur_in * m->samplerate / 90000 ) - m->sum_dur;
+ int64_t dur_in = buf->stop - buf->start;
+ duration = dur_in * m->samplerate / 90000 + bias;
if ( duration <= 0 )
{
/* We got an illegal mp4/h264 duration. This shouldn't
duration = 1000 * m->samplerate / 90000;
}
m->sum_dur += duration;
+ m->sum_dur_in += dur_in;
}
else
{
duration = MP4_INVALID_DURATION;
}
- /* Here's where the sample actually gets muxed.
- If it's an audio sample, don't offset the sample's playback.
- If it's a video sample and there are no b-frames, ditto.
- If there are b-frames, offset by the initDelay plus the
- difference between the presentation time stamp x264 gives
- and the decoding time stamp from the buffer data. */
+ // Here's where the sample actually gets muxed.
if( !MP4WriteSample( m->file,
mux_data->track,
buf->data,
buf->size,
duration,
- ((mux_data->track != 1) ||
- (job->areBframes==0) ||
- (job->vcodec != HB_VCODEC_X264)) ? 0 : ( buf->renderOffset * m->samplerate / 90000),
+ offset,
((buf->frametype & HB_FRAME_KEY) != 0) ) )
{
hb_error("Failed to write to output file, disk full?");
if (job->areBframes)
{
// Insert track edit to get A/V back in sync. The edit amount is
- // the rendering offset of the first sample.
- MP4AddTrackEdit(m->file, 1, MP4_INVALID_EDIT_ID, MP4GetSampleRenderingOffset(m->file,1,1),
- MP4GetTrackDuration(m->file, 1), 0);
+ // the init_delay.
+ int64_t edit_amt = m->init_delay * m->samplerate / 90000;
+ MP4AddTrackEdit(m->file, 1, MP4_INVALID_EDIT_ID, edit_amt,
+ MP4GetTrackDuration(m->file, 1), 0);
if ( m->job->chapter_markers )
{
// apply same edit to chapter track to keep it in sync with video
MP4AddTrackEdit(m->file, m->chapter_track, MP4_INVALID_EDIT_ID,
- MP4GetSampleRenderingOffset(m->file,1,1),
+ edit_amt,
MP4GetTrackDuration(m->file, m->chapter_track), 0);
}
}
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