does async or vsync options help? On 4/4/17, Valeriy Shevchuk <[email protected]> wrote: > Hello, everyone. > I'm trying to use FFmpeg to record video and 3 audio sources and use it to > generate 3 different video files - each file should contain the same video > stream but the different audio stream. The problem is that I got audio sync > issues. The first audio stream is synced perfectly, but the second one has > 1 sec lag, and the third one has like 2 sec lag. > > I've made a few tests so far and it seems that root cause of the issue is > initialization time of video/audio devices. So, one device is already > recording something but the second is still being opened and so on. I've > tried to change input devices order and after that audio streams still have > the same issue BUT if before 2nd and 3rd audio streams were some time ahead > of video, after reordering they became to lag after the audio (audio for > the same event appears with some delay). So this test confirms my version > about device initialization times. > > But the question still, why the first audio stream is synchronized > properly, while other 2 are not. and also, how could I overcome this > issues? Any workarounds and ideas are highly appreciated. > > Here is FFmpeg command I'm using and it's output. > > ffmpeg.exe -f dshow -video_size 1920x1080 -i video="Logitech HD Webcam >> C615" -f dshow -i audio="Microphone (HD Webcam C615)" -f dshow -i >> audio="Microphone Array (Realtek High Definition Audio)" >> -filter_complex "[1:a]volume=1[a1];[2:a]volume=1[a2]" -vf >> scale=h=1080:force_original_aspect_ratio=decrease -vcodec libx264 >> -pix_fmt yuv420p -crf 23 -preset ultrafast -acodec aac -vbr 5 -threads 0 >> -map v:0 -map [a1] -map [a2] -f tee >> "[select=\'v,a:0\']C:/Users/vshevchu/Desktop/123/111/111_jjj1.avi| >> [select=\'v,a:1\']C:/Users/vshevchu/Desktop/123/111/111_jjj2.avi" > > > Here is the output: > https://pastebin.com/A3FL05My > > PS. Actually, the issue is exactly the same when I'm not using "tee" muxer > but writing all the audio streams to one container. So, "tee" isn't a > suspect. > _______________________________________________ > ffmpeg-user mailing list > [email protected] > http://ffmpeg.org/mailman/listinfo/ffmpeg-user > > To unsubscribe, visit link above, or email > [email protected] with subject "unsubscribe". _______________________________________________ ffmpeg-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/ffmpeg-user
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