On 12/19/17, Mark Corner <mcor...@gmail.com> wrote: > I am having trouble with amix producing different results with different > input orders and only one input to amix staying in sync with the video. > > I am starting with three video and three audio files, vp8 and opus > encoded. There is a video and audio that go together and are about 32 > minutes long. Then there are two pairs of audio and video, each about 16 > minutes long. > > First I combine the three videos using an overlay: > ffmpeg -y -itsoffset 0 -i > /tmp/RM359a097bf459c327e34954525862d2b7/RTd9075ac090a32a21e71269e6b08f4053-reproces > sed.mkv -itsoffset 2.364 -i > /tmp/RM359a097bf459c327e34954525862d2b7/RT21a59c19d91a7644b8c76d3fd12c3b32-reproc > essed.mkv -itsoffset 983.503 -i > /tmp/RM359a097bf459c327e34954525862d2b7/RT4d34aa2bae28a73f8079a6e1b65b3aa4-re > processed.mkv -filter_complex > "[0]pad=iw*2:ih[t0];[t0][1]overlay=W/2:0[t1];[t1][2]overlay=0:0[t2]" -map > [t2] > -an -c:v libvpx -crf 23 -b:v 1M -cpu-used 3 -threads 8 > /tmp/RM359a097bf459c327e34954525862d2b7/output_video. > webm > > That works fine. > > Then I combine the audio (this is where the problem is): > ffmpeg -y -i > /tmp/RM359a097bf459c327e34954525862d2b7/RT2568dcb62e48c44c4ac61094c4377553 > -i /tmp/RM359a097bf45 > 9c327e34954525862d2b7/RTb5d9c3c0a59e98061159ddb310587b71 -i > /tmp/RM359a097bf459c327e34954525862d2b7/RT955f8ed > 764b5fda55a4dcd23cfed673d -filter_complex > "[0]adelay=25|25[t0];[1]adelay=2363|2363[t1];[2]adelay=983525|9835 > 25[t2];[t2][t1][t0]amix=inputs=3" -strict -2 -c:a libopus > /tmp/RM359a097bf459c327e34954525862d2b7/output_audi > o.mka > > And then merge the audio and video together: > ffmpeg -y -i /tmp/RM359a097bf459c327e34954525862d2b7/output_audio.mka -i > /tmp/RM359a097bf459c327e34954525862d2b7/output_video.webm -c:v copy -c:a > copy /tmp/RM359a097bf459c327e34954525862d2b7/full.webm > > The problem is that the audio and video are only in sync for what ever is > first in the amix filter.... So in the above example, the t2 audio input > will be in sync, but not the t1 or t0. If I change the order to something > like [t1][t2][t0], then the t1 audio is in sync, but none of the others. > In fact the length of the output_audio.mka will differ based on the order > of inputs to amix.... As far as I understand, the order to amix shouldn't > matter at all. > > Thanks for any advice you can offer.
Perhaps you need to use asetpts filter after each adelay to reset pts to sane value? _______________________________________________ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".