I'm changing containers from MKV to MP4. I think I'm close, but I can't figure out how to keep the Subtitle and Attachment (font for the subtitles) streams.
Stream 0 Video (H264) - Stream 1 Audio (mp4a) - Stream 2 Audio (mp4a) - Stream 3 Subtitles (ssa) - Stream 4 Attachment (tff)
I've tried a lot of variations, but most recently these 3:
ffmpeg -i input.mkv -map 0:v -map 0:a:0 -map 0:a:1 -c copy -c:s mov_text output.mp4
ffmpeg -i input.mkv -map 0:v -map 0:a:0 -map 0:a:1 -map 0:s -map 0:t -c copy output.mp4
ffmpeg -i input.mkv -map 0:v -map 0:a:0 -map 0:a:1 -c copy -c:s copy -c:t copy output.mp4
I wind up with the video stream and the 2 audio streams only.
Thank you!