Handy tip for trimming demo videos
Thought I'd document the process I used for trimming down my React conf demo videos in case it might be useful to someone else in the future.
Let's say I have a 40 second video named
original-video.mp4, and I want to only keep the following sections (in seconds): 1-8, 10-11, 20-33
I could create 3 chunks using
ffmpeg like so:
ffmpeg -i original-video.mp4 -ss 1 -t 7 piece-a.mp4 -ss 10 -t 1 piece-b.mp4 -ss 20 -t 33 piece-c.mp4
Then write the names of these pieces to a text file:
cat >> video-pieces.txt << EOF file 'piece-a.mp4' file 'piece-b.mp4' file 'piece-c.mp4' EOF
Then lastly, use
ffmpeg to stitch them back together into a single file:
ffmpeg -f concat -i video-pieces.txt -c copy trimmed-video.mp4
I know other tools (like QuickTime) let you trim, but I don't know if they let you splice sections out. (I'm not a QuickTime power user.) The above is pretty easy and fast though so...hope it helps someone!