I am trying to slow down a video+audio a little bit, using this FFMpeg command:

ffmpeg.exe -i video.mp4 -filter_complex "[0:v]yadif,framerate=30,setpts=1.2*PTS[v];[0:a]atempo=0.8[a]" -map "[v]" -map "[a]" -vsync vfr -vcodec h264_qsv out.mp4

but this command gives lots of warnings like this:

[mp4 @ 00000194a7089040] Non-monotonous DTS in output stream 0:0; previous: 2002, current: 2002; changing to 2003. This may result in incorrect timestamps in the output file.

Screenshot and the video and audio are out of sync on the out.mp4

How can I slow down a video and audio using FFMpeg or HandBrakeCLI ?

1 Answer 1


This seems to work well:

ffmpeg.exe -r 24 -i video.mp4 -filter_complex "[0:v]yadif[v];[0:a]atempo=0.8[a]" -map "[v]" -map "[a]" -vsync vfr -vcodec h264_qsv out.mp4

Source: #handbrake channel on Freenode, user BradleyS

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.