# Media tools

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

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 |
| --- | --- |
| 
`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:

```console
$ 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.

## See also

-   [Everyday apps](everyday-apps.html), for Shottr
    
-   [ffmpeg documentation](https://ffmpeg.org/documentation.html)
    
-   [pngquant](https://pngquant.org)
    
-   [poppler](https://poppler.freedesktop.org)