I have a 2 audio track mxf file and need to clone the video but create 8 audio tracks. The tracks 1 and 2 should be copied into 3 and 4, 5 and 6 and 7 and 8. Some files that I'm dealing with are 4 track files with the silence in 3 and 4, and some are genuine 2 track mxf's with a mono audio in each one. Not wearing my ffmpeg boots for quite some time, any ideas how to achieve this? Thanks!
1 Answer
In case anyone ever needs it, this worked out for me, the combination of split filter and map.
-filter_complex "[0:1]asplit=4[1:1][1:3][1:5][1:7];[0:2]asplit=4[2:2][2:4][2:6][2:8]"
-map 0:v:0 -map "[1:1]" -map "[2:2]" -map "[1:3]" -map "[2:4]" -map "[1:5]" -map "[2:6]" -map "[1:7]" -map "[2:8]"
The whole command:
ffmpeg -y -i <input_2_tracks>.mxf -filter_complex \
"[0:1]asplit=4[1:1][1:3][1:5][1:7];[0:2]asplit=4[2:2][2:4][2:6][2:8]" \
-map 0:v:0 -map "[1:1]" -map "[2:2]" -map "[1:3]" -map "[2:4]" -map "[1:5]" \
-map "[2:6]" -map "[1:7]" -map "[2:8]" \
-c:v copy -c:a pcm_s24le -ar 48000 <output_8_tracks>.mxf
This will take input with any number of tracks and copy the first two tracks into the eight tracks in the output file. The asplit arguments [1:1][1:3] etc. may be named arbitrarily.
