Sometimes it is quite convenient and quick to edit media files (for eg. resize images) via command line. Below are such helpful tools for Mac OS X.
Table of contents#
Images #
Mac has an inbuild CLI tool called sips. It modifies the images in-place. To save the updated image in a separate copy, use --out [outfilename] in the command.
Re-size image#
sips -z [height] [width] file.png: Re-sizes image to specified dimensions, which may alter the actual aspect ratio.
sips -Z [heightwidth] file.png: This maintains the aspect ratio and [heightwidht] value will be the maximum value that can be for the height and width of the image (the other dimension will get set acc to its aspect ratio).
Example
sips -z 640 480 file1.png sips -Z 640 file2.png
You can view the current dimension details of an image by looking at the image's info.
Rotate image#
sips -r [degrees] file.png
Example:
sips -r 90 file.jpg --out rotatedfile.jpg
Other options:
-f [horizontal or vertical]: Flips the image
-c [pixelsH pixelsV]: Crops the image to height and width
Check out all the options available by doing sips --help
Videos #
For video editing via command line, you'll have to install a tool called ffmpeg which will make your life easier.
You can install using Homebrew:
$ brew install ffmpeg
Change format#
Eg. convert mp4 to mov
ffmpeg -i input.mp4 output.mov
Tip: You can also make gifs from video using this command
Change resolution / dimension#
Eg. Change video resolution to 1280x720. Can be used to reduce the resolution and therefore the size
ffmpeg -i input.mp4 -c:a copy -s 1280x720 output.mp4
Trim video#
Eg. 1) Trim from 00:00:10 to 00:00:20 (hh:mm:ss)
ffmpeg -i input.mp4 -ss 00:00:10 -to 00:00:20 -c copy output.mp4
Eg. 2) Trim ten seconds starting from 00:01:00
ffmpeg -i input.mp4 -c:av copy -ss 00:01:00 -t 10 output.mp4
Extract audio from video#
ffmpeg -i clip.mp4 -vn audio_only.mp3
Audio #
We are going to use the same command line tool ffmpeg to edit audio files too. If you don't have it, install it via Homebrew.
$ brew install ffmpeg
The commands are same as the commands for editing the videos actually.
Trim audio#
Eg. Trim from 00:00:20 to 00:00:40 (hh:mm:ss)
ffmpeg -ss -i input.mp3 00:00:20 -to 00:00:40 -c copy output.mp3
Change format#
Eg. convert mp3 to wav
ffmpeg -i input.mp3 output.wav
That's all for now. Hope you find these useful and get comfortable and quick with editing media files via Command Line.