[FFmpeg-user] libvpx + libopus creates files with negative starttime for audio

Mike Martin redtux1 at gmail.com
Sat Sep 4 16:15:10 EEST 2021

I have come across an oddity with transcoding files to vp9/libopus from mp4

The resulting files have a negative starttime for audio , nearly all the
time this is -.007.

I noticed it when I was concating files using demux concat and specifying
video duration

This resulted in concat operation stopping at end of first file.

Removing the duration from the conf file seems to resolve this.

Seems to be just this combination of codecs

More information about the ffmpeg-user mailing list