I have two video tracks (one with alpha transparency and both without audio) and an audio file, I need to put them all together with the same beginning.
so:
I only managed to mix the two videos together with this code:
ffmpeg
-i "alpha.mov" -i "background.mov"
-filter_complex "nullsrc=size=1920x1080 [base];
[0:v] setpts=PTS-STARTPTS [top];
[1:v] setpts=PTS-STARTPTS [bottom];
[base][top] overlay=shortest=1 [temp];
[temp][bottom] overlay=shortest=1"
-acodec libvo_aacenc -vcodec libx264 out.mp4
But I can't add the audio track.
Furthermore, the base must be of a specific color (white) and when the background clip ends it remains black
Can you help me? Thank you