ffmpeg - Slow down video and loop/repeat audio

Question

I am trying to use ffmpeg to slow down a video speed by 25% (75% speed) without changing the audio speed.

ffmpeg -i input_video.mkv -filter:v "setpts=1.3*PTS" "SlowVideo25.mp4"

On doing so, the audio finishes first and the video continues to play for some more seconds. I want to use ffmpeg to loop/repeat the audio track in this case. So when the audio finishes, it plays the audio from the beginning for the remainder of the video.

Is this do-able using ffmpeg?

Answer 1

since there is no loop option on the mapped stream; therefore you need 2 steps

1. ffmpeg -y -stream_loop 2 -i https://www.learningcontainer.com/wp-content/uploads/2020/05/sample-mp4-file.mp4 output.wav
2. ffmpeg -y -i output.wav -i https://www.learningcontainer.com/wp-content/uploads/2020/05/sample-mp4-file.mp4 -filter:v "setpts=1.3*PTS" -shortest output.mp4

Note: stream_loop number is the ceiling of factor