On Tue, March 19, 2013 6:10 pm, Federico Bruni wrote: > Il 19/03/2013 02:25, Len Ovens ha scritto: >>> I have another issue with the tutorial above. >>> >It says: >>> >"Now you have two separate files, an .mkv and a .wav file and because >>> >jack_capture was started right after ffmpeg audio should be no more >>> out >>> >of sync then just a few millisecs." >>> > >>> >Actually my files are out of sync because they have different >>> durations. >>> >Video is 5:31 and audio is 9:21. >> My first guess is a frame rate issue... like a half frame rate that is >> also mistranslated from 25hz to 29.*dropframe (or vise versa). It really >> doesn't matter at this point, check two things. Listen to the wave, does >> it sound right"? Watch the video stream, does it look really fast? Do >> they >> play back at the listed times? >> >> Are you using spdif for audio in? If so, where is it getting sync from? >> >> These are all shots in the dark. The first thing is to play them back >> and >> see if there is an issue with audio or video or both. > > Your guess is probably right. > The audio is ok, while the video is a bit too fast. > > Yes, they play back at the listed times. > Here's what ffmpeg say: > > Input #0, matroska,webm, from 'screencast_video_20130318-23h53.mkv': > Metadata: > ENCODER : Lavf54.29.104 > Duration: 00:05:31.00, start: 0.000000, bitrate: 426 kb/s > Stream #0:0: Video: h264 (High 4:4:4 Predictive), yuv444p, > 1280x800, SAR 1:1 DAR 8:5, 30 fps, 30 tbr, 1k tbn, 60 tbc (default) > > Input #0, wav, from 'screencast_audio_20130318-23h53.wav': > Duration: 00:09:21.79, bitrate: 2304 kb/s > Stream #0:0: Audio: pcm_s24le ([1][0][0][0] / 0x0001), 48000 Hz, > stereo, s32, 2304 kb/s > > But I don't understand... I've recorded at 30 fps and I'm watching at 30 > fps. Why it's playing faster than the recording? > It possible that your machine was dropping frames while recording. You can slow down playback 'stretch" the video to the timelength you require. http://ffmpeg.org/trac/ffmpeg/wiki/How%20to%20speed%20up%20/%20slow%20down%20a%20video -- Patrick Shirkey Boost Hardware Ltd _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user
