FFMPEG: Loop video to the length of audio

Question

E.g. if video is 1 minute, but audio is 1 hour. Make video loop throughout for 1 hour of the audio track.

I use this solution to loop image through the lenght of the audio

ffmpeg -y -loop 1 -r 6 -i image.jpg -i audio.mp3 -shortest -c:v libx264 -preset ultrafast -tune stillimage -pix_fmt yuv420p -c:a copy output.mp4

But it doesn't work for video, replacing image.jpg with video.mp4 will give error no loop found.

Here: stackoverflow.com/a/55841289/3310334
– minseong
Commented May 7, 2020 at 17:36 — minseong, Commented May 7, 2020 at 17:36

Gyan · Accepted Answer · 2018-02-13 16:04:18Z

9

For video, stream_loop option should be used.

ffmpeg -y -stream_loop -1 -i video -i audio.mp3 -fflags +shortest -max_interleave_delta 50000 -c copy output.mp4

You'll have to use a very recent version of ffmpeg (> Nov '17) as stream_loop had a bug, only recently fixed.

Since video encoding is expensive in terms of time and CPU, I've used streamcopy. For most videos, this is fine. Else, you'll have to re-encode.

Edit: another bug related to stream_loop, see workaround below

ffmpeg  -stream_loop -1 -i 1.mp4 -c copy -v 0 -f nut - | ffmpeg -thread_queue_size 10K -i - -i 1.mp3 -c copy -map 0:v -map 1:a -shortest -y out.mp4

answered Feb 11, 2018 at 16:02

Gyan

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Hello. This just strips the audio to the length of video, I meant opposite. Loop video throughout to the length of the audio. For now I'm using solution at video.stackexchange.com/questions/12905/…
– user3108268
Commented Feb 11, 2018 at 20:18
Use edited command.
– Gyan
Commented Feb 12, 2018 at 5:23
I set the video part to video.mp4, video plays until it's original length and stops while audio keeps going, video just stills last frame throughout.
– user3108268
Commented Feb 12, 2018 at 22:16
Share full log.
– Gyan
Commented Feb 13, 2018 at 5:05
1

See new command at end
– Gyan
Commented Feb 13, 2018 at 16:04

| Show 4 more comments

Chen Tian · Accepted Answer · 2021-08-09 15:08:50Z

Well, now the default behavior of current/latest ffmpeg via:

c:\sbin\ffmpeg.exe -i "D:\video.m4s" -i "\audio.m4s" -c:v copy -c:a copy "D:\combined.mp4"

is padding/looping the last frame of the video until audio.length === video.length.

See if this is acceptable for you.

For details behavior:

if (audio.length < video.length), then pad the audio with silent, so that audio.length === video.length
if (audio.length > video.length), then pad the video with the last frame of this video, so that audio.length === video.length

2 Answers 2