FFmpeg
From Leo's Notes
This page was last edited on 21 July 2019, at 23:49.
Usage
Merging mp4 and m4a
Using ffmpeg you can combine the two together:
# ffmpeg -i video.mp4 -i audio.m4a -acodec copy -vcodec copy output.mp4
Extracting a video section
To extract a video section:
# ffmpeg -i input.mp4 -ss 00:00:15 -t 00:00:10 -async 1 output.mp4
Where:
| -ss | The start time in HH:MM:SS |
|---|---|
| -t | The length of the video in HH:MM:SS |
Slideshow to Video
See: https://trac.ffmpeg.org/wiki/Slideshow
Example usage:
## Remove any empty image files (explained below)
# find ./images -size 0 -print0
The * needs to be escaped or contained in single quotes because ffmpeg will do the globbing, not the shell.
Empty files will cause ffmpeg to stop processing additional files. Run find ./slideshow -size 0 -print0 to delete zero-sized files to prevent this from happening.
Issues
Copying DASH video (via -vcodec copy) using versions older than 0.10 will result in an empty file because it is unable to read the video contents.