Media tools

ffmpeg, sox, jpegoptim, pngquant and poppler: convert and shrink video, audio, images and PDFs.

.md

Five command-line tools for the media that ends up in a repository or a message: video and audio with ffmpeg and sox, images with jpegoptim and pngquant, and PDFs with poppler.

On the workstation

Installed by the ffmpeg, sox, jpegoptim, pngquant and poppler formulae.
poppler brings pdftotext, pdftoppm and pdfinfo.

Keys and commands

Key or command Does

Key or command	Does
`ffmpeg -i in.mov -c:v libx264 -crf 23 out.mp4`	Convert a screen recording to a small MP4
`ffmpeg -i in.mp4 -vf "fps=12,scale=800:-1" out.gif`	Make a GIF for a README or a pull request
`ffmpeg -i in.mp4 -vn -c:a copy out.m4a`	Take the audio out of a video
`sox in.wav -r 16000 -c 1 out.wav`	Resample audio to 16 kHz mono, as speech models expect
`jpegoptim --max=85 --strip-all *.jpg`	Shrink JPEGs and drop their metadata
`pngquant --quality=65-80 --strip --ext .png --force *.png`	Shrink PNGs in place and drop their metadata
`pdftotext -layout in.pdf -`	Print a PDF’s text, keeping its columns
`pdftoppm -png -r 150 in.pdf page`	Render each page to a PNG
`pdfinfo in.pdf`	Show a PDF’s pages, size and producer

ffmpeg -i in.mov -c:v libx264 -crf 23 out.mp4

Convert a screen recording to a small MP4

ffmpeg -i in.mp4 -vf "fps=12,scale=800:-1" out.gif

Make a GIF for a README or a pull request

ffmpeg -i in.mp4 -vn -c:a copy out.m4a

Take the audio out of a video

sox in.wav -r 16000 -c 1 out.wav

Resample audio to 16 kHz mono, as speech models expect

jpegoptim --max=85 --strip-all *.jpg

Shrink JPEGs and drop their metadata

pngquant --quality=65-80 --strip --ext .png --force *.png

Shrink PNGs in place and drop their metadata

pdftotext -layout in.pdf -

Print a PDF’s text, keeping its columns

pdftoppm -png -r 150 in.pdf page

Render each page to a PNG

pdfinfo in.pdf

Show a PDF’s pages, size and producer

With zc-workstation

The screenshots in these docs are PNGs. Before committing one, shrink it:

$ pngquant --quality=65-80 --strip --ext .png --force docs/modules/ROOT/images/*.png

--strip drops metadata, such as which machine and app made the image.

Media tools

On the workstation

Keys and commands

With zc-workstation

See also

Keyboard shortcuts