[FFmpeg-user] emerge has unconnected output? Works on FFMPEG 4, not 3

[Michael Koch]

Am 23.11.2020 um 16:14 schrieb Karl Messner:
> Michael,
>
> Thank you so much for your help. I made the changes you suggested and now I'm getting this:
>
>
> ffmpeg -report -i videos/intro720.mp4 -i videos/raw.mp4 -i videos/outro720.mp4 -i videos/music.mp3 -filter_complex " \
> [0]scale=1280:720:force_original_aspect_ratio=decrease,pad=1280:720:(ow-iw)/2:(oh-ih)/2,setsar=1[v0];\
> [1]scale=1280:720:force_original_aspect_ratio=decrease,pad=1280:720:(ow-iw)/2:(oh-ih)/2,setsar=1[v1];\
> [2]scale=1280:720:force_original_aspect_ratio=decrease,pad=1280:720:(ow-iw)/2:(oh-ih)/2,setsar=1[v2];\
> [3:a]volume=.015[a0];\
> [1:a][a0]amerge[amix];\
> [v0][0:a:0] [v1][amix] [v2][2:a:0]concat=n=3:v=1:a=1[v][a]" -map "[v]" -map "[a]" -f mp4 videos/out1606144376.mp4 2>&1
>
>
>
>
>
> [Parsed_amerge_10 @ 0x21c96c0] No channel layout for input 1
> [Parsed_amerge_10 @ 0x21c96c0] No channel layout for input 2
> [AVFilterGraph @ 0x1a76460] The following filters could not choose their formats: Parsed_amerge_10
> Consider inserting the (a)format filter near their input or output.
> Error configuring complex filters.
> Input/output error

Are you sure that "amerge" is the correct filter for your purpose? Why 
not the "amix" filter?

Michael