ffmpeg - Slow down video and loop/repeat audio
since there is no loop option on the mapped stream; therefore you need 2 steps

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

Note: stream_loop number is the ceiling of factor