/* libmp4v2 handle */
MP4FileHandle file;
- /* 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
+ int64_t sum_dur; // sum of video frame durations so far
// bias to keep render offsets in ctts atom positive (set up by encx264)
int64_t init_delay;
MP4TrackId chapter_track;
int current_chapter;
uint64_t chapter_duration;
-
- /* Sample rate of the first audio track.
- * Used for the timescale
- */
- int samplerate;
};
struct hb_mux_data_s
/* Flags for enabling/disabling tracks in an MP4. */
typedef enum { TRACK_DISABLED = 0x0, TRACK_ENABLED = 0x1, TRACK_IN_MOVIE = 0x2, TRACK_IN_PREVIEW = 0x4, TRACK_IN_POSTER = 0x8} track_header_flags;
- if( (audio = hb_list_item(title->list_audio, 0)) != NULL )
- {
- /* Need the sample rate of the first audio track to use as the timescale. */
- m->samplerate = audio->config.out.samplerate;
- audio = NULL;
- }
- else
- {
- m->samplerate = 90000;
- }
-
/* Create an empty mp4 file */
if (job->largeFileSize)
/* Use 64-bit MP4 file */
mux_data = malloc( sizeof( hb_mux_data_t ) );
job->mux_data = mux_data;
- /* When using the standard 90000 timescale, QuickTime tends to have
- synchronization issues (audio not playing at the correct speed).
- To workaround this, we use the audio samplerate as the
- timescale */
- if (!(MP4SetTimeScale( m->file, m->samplerate )))
+ if (!(MP4SetTimeScale( m->file, 90000 )))
{
hb_error("muxmp4.c: MP4SetTimeScale failed!");
*job->die = 1;
{
/* Stolen from mp4creator */
MP4SetVideoProfileLevel( m->file, 0x7F );
- mux_data->track = MP4AddH264VideoTrack( m->file, m->samplerate,
+ mux_data->track = MP4AddH264VideoTrack( m->file, 90000,
MP4_INVALID_DURATION, job->width, job->height,
job->config.h264.sps[1], /* AVCProfileIndication */
job->config.h264.sps[2], /* profile_compat */
else /* FFmpeg or XviD */
{
MP4SetVideoProfileLevel( m->file, MPEG4_SP_L3 );
- mux_data->track = MP4AddVideoTrack( m->file, m->samplerate,
+ mux_data->track = MP4AddVideoTrack( m->file, 90000,
MP4_INVALID_DURATION, job->width, job->height,
MP4_MPEG4_VIDEO_TYPE );
if (mux_data->track == MP4_INVALID_TRACK_ID)
// (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;
+ offset = buf->start + m->init_delay - m->sum_dur;
+ if ( offset < 0 )
+ {
+ hb_log("MP4Mux: illegal render offset %lld, start %lld,"
+ "stop %lld, sum_dur %lld",
+ offset, buf->start, buf->stop, m->sum_dur );
+ offset = 0;
+ }
}
/* Add the sample before the new frame.
// 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.
+ // The initial and final chapters can be very short (a second or
+ // less) since they're not really chapters but just a placeholder to
+ // insert a cell command. We don't write chapters shorter than 1.5 sec.
duration = m->sum_dur - m->chapter_duration + offset;
- if ( duration <= 0 )
+ if ( duration >= (90000*3)/2 )
{
- /* The initial & final chapters can have very short durations
- * (less than the error in our total duration estimate) so
- * the duration calc above can result in a negative number.
- * when this happens give the chapter a short duration (1/3
- * of an ntsc frame time). */
- duration = 1000 * m->samplerate / 90000;
- }
+ chapter = hb_list_item( m->job->title->list_chapter,
+ buf->new_chap - 2 );
- chapter = hb_list_item( m->job->title->list_chapter,
- buf->new_chap - 2 );
+ MP4AddChapter( m->file,
+ m->chapter_track,
+ duration,
+ (chapter != NULL) ? chapter->title : NULL);
- MP4AddChapter( m->file,
- m->chapter_track,
- duration,
- (chapter != NULL) ? chapter->title : NULL);
-
- m->current_chapter = buf->new_chap;
- m->chapter_duration += duration;
+ m->current_chapter = buf->new_chap;
+ m->chapter_duration += duration;
+ }
}
- // 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;
+ // We're getting the frames in decode order but the timestamps are
+ // for presentation so we have to use durations and effectively
+ // compute a DTS.
+ duration = buf->stop - buf->start;
if ( duration <= 0 )
{
/* We got an illegal mp4/h264 duration. This shouldn't
be possible and usually indicates a bug in the upstream code.
Complain in the hope that someone will go find the bug but
try to fix the error so that the file will still be playable. */
- hb_log("MP4Mux: illegal duration %lld, bias %lld, start %lld (%lld),"
- "stop %lld (%lld), sum_dur %lld",
- duration, bias, buf->start * m->samplerate / 90000, buf->start,
- buf->stop * m->samplerate / 90000, buf->stop, m->sum_dur );
+ hb_log("MP4Mux: illegal duration %lld, start %lld,"
+ "stop %lld, sum_dur %lld",
+ duration, buf->start, buf->stop, m->sum_dur );
/* we don't know when the next frame starts so we can't pick a
- valid duration for this one so we pick something "short"
- (roughly 1/3 of an NTSC frame time) and rely on the bias calc
- for the next frame to correct things (a duration underestimate
- just results in a large bias on the next frame). */
- duration = 1000 * m->samplerate / 90000;
+ valid duration for this one. we pick something "short"
+ (roughly 1/3 of an NTSC frame time) to take time from
+ the next frame. */
+ duration = 1000;
}
m->sum_dur += duration;
- m->sum_dur_in += dur_in;
}
else
{
hb_chapter_t *chapter = NULL;
int64_t duration = m->sum_dur - m->chapter_duration;
/* The final chapter can have a very short duration - if it's less
- * than a second just skip it. */
- if ( duration >= m->samplerate )
+ * than 1.5 seconds just skip it. */
+ if ( duration >= (90000*3)/2 )
{
chapter = hb_list_item( m->job->title->list_chapter,
{
// Insert track edit to get A/V back in sync. The edit amount is
// the init_delay.
- int64_t edit_amt = m->init_delay * m->samplerate / 90000;
+ int64_t edit_amt = m->init_delay;
MP4AddTrackEdit(m->file, 1, MP4_INVALID_EDIT_ID, edit_amt,
MP4GetTrackDuration(m->file, 1), 0);
if ( m->job->chapter_markers )
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