ffmpeg: Changes to FPS only work if I don't include audio in the export, how can I keep audio and choose the FPS value?

Question

How can I export a video to .mjpeg at my selected FPS value (7 FPS for stop motion video) while including audio in the export?

I use the -i input command in ffmpeg to include my .ogg audio file:

ffmpeg -r 7 -i /path/to/audio/file/audioexample.ogg -i "$IMAGEPATH/%06d.jpg" -vcodec mjpeg -shortest "$VIDEOFILE".mov

This doesn't export at 7 fps, it's much faster, looks like about 25 FPS. The -shortest option works and cuts the audio length to the video length, otherwise without -shortest the audio goes on longer than the video, so about 25 FPS either way regardless of -shortest.

The FPS will only correctly export at 7 FPS if I remove the audio from the ffmpeg export like this:

ffmpeg -r 7 -i "$IMAGEPATH/%06d.jpg" -vcodec mjpeg "$VIDEOFILE".mov

I'm using Linux Stopmotion video creation software which uses this ffmpeg command.

How can I include my audio but still have control of the FPS value using ffmpeg?

Answer 1

The location of the audio -i input within the ffmpeg command makes a difference. If the audio is input right after the FPS value, then the FPS value doesn't work and instead uses a default FPS. Put your sound input after your existing images input then the FPS value you input will work.

The working command is:

ffmpeg -r 7 -i "$IMAGEPATH/%06d.jpg" -i /path/to/audio/file/audioexample.ogg -vcodec mjpeg -shortest "$VIDEOFILE".mov