I would like to add an image intro to a video for about 5 seconds but the time could be variable. I made a 5 seconds during intro.mkv with the following command:
ffmpeg -loop 1 -f image2 -i png.png -c:v libx264 -t 5 out.mp4
The problem is that cmd doesn't know the following command which is exactly what I need. This command is copy pasted from the FAQ of FFmpeg.
ffmpeg -i opening.mkv -i episode.mkv -i ending.mkv -filter_complex \
"[0:0] [0:1] [0:2] [1:0] [1:1] [1:2] [2:0] [2:1] [2:2]
concat=n=3:v=1:a=2 [v] [a1] [a2]" \
-map '[v]' -map '[a1]' -map '[a2]' output.mkv
The error is: (2> output.txt isnt working for some reason)