Merge MP4 files with ffmpeg

Question

I have two MP4 files in which there is video and audio, and one contains only video,

I need to combine both files - this means playing both files at the same time. I do not want to concatenate them (add one after the other).

So how can I do this?

Answer 1

Side by side with audio from one of the inputs

_{Two separate scenes from Gymkata, but probably a bad example of choice, because it seems like two people are hiding behind a wall with their faces and watching the fighting of an epic battle.}

Assuming both videos have the same format, frame size, frame rate, etc:

ffmpeg -i videoandaudio.mp4 -i video.mp4 -filter_complex \
"[0:v]pad=iw*2:ih,setpts=PTS-STARTPTS[bg]; \
 [1:v]setpts=PTS-STARTPTS[fg]; \
 [bg][fg]overlay=shortest=1:x=w,format=yuv420p[filtered]" \
-map "[filtered]" -map 0:a -codec:a copy output.mp4

This filtergraph will be:

• pad , setpts, , 0.
• PTS setpts.
• , [bg] [fg].
• format , , chroma , FFmpeg.

:

• .
• , ffmpeg. . FFmpeg Download ffmpeg ffmpeg .
• . FFmpeg x264 Encoding Guide.