I know files captured with Final Cut Pro 7 have this attribute. The software starts recording the audio and video tracks and then inserts metadata for each track to indicate the offset of the start of the track relative to the start time of the container. This aligns the tracks, to this point.
Chris On Friday, March 20, 2015, Andrzej Borucki <[email protected]> wrote: > I convert .mov file created by Canon to H.264, container mp4 - QuickTime(?) > ffprobe give me: > [format] > format_name=mov,mp4,m4a,3gp,3g2,mj2 > format_long_name=QuickTime / MOV > start_time=0.045000 > duration=7.808000 > size=954931 > > video stream [streams.stream.0] > codec_name=h264 > codec_time_base=1/180000 > time_base=1/90000 > start_pts=5940 > start_time=0.066000 > duration_ts=702702 > duration=7.807800 > bit_rate=810598 > nb_frames=234 > > audio [streams.stream.1] > codec_name=aac > codec_time_base=1/48000 > time_base=1/48000 > start_pts=2160 > start_time=0.045000 > duration_ts=372736 > duration=7.765333 > > After converting it to h264: > [format] > start_time=-0.033333 > duration=7.842000 > size=889221 > bit_rate=907136 > > [streams.stream.0] > r_frame_rate=30000/1001 > avg_frame_rate=30000/1001 > time_base=1/30000 > start_pts=0 > start_time=0.000000 > duration_ts=235235 > duration=7.841167 > > [streams.stream.1] > time_base=1/48000 > start_pts=-1600 > start_time=-0.033333 > duration_ts=374336 > duration=7.798667 > > Why start_time is not zero? In second movie, audio begins before or after > start movie? > In first - both video and audio start_time is non zero, what it means? > _______________________________________________ > ffmpeg-user mailing list > [email protected] <javascript:;> > http://ffmpeg.org/mailman/listinfo/ffmpeg-user > _______________________________________________ ffmpeg-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/ffmpeg-user
