• ffmpeg

    2 min read · Documentation Sound Vision

    Basics

    Translate a media file to a new type.

    ffmpeg -i [input file] output_file.mkv

    The input file might be a device, such as a camera.

    #Record screen

    Take the format as 'grab the x11 screen'.

    1ffmpeg -f x11grab -s [screensize] -i :0.0 out.mkv

    Get screensize with

    1xrandr -q

    or maybe just...

    1ffmpeg -f x11grab -s " …

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  • imagemagick

    2 min read · Documentation Vision

    Convert jpg to png.

    1convert image.jpg image.png

    1convert image.jpg -quality 50 image.jpg

    'Quality' must be from 1 to 100.

    1convert -resize 50% image.jpg image2.jpg

    Resizing only changes jpegs. Change a png with:

    1convert input.png png8:out.png

    Invert Colours

    1convert input.jpg output.jpg -negate

    Make Images Smaller

    1 …

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  • Markdown to PDF

    1 min read · Documentation Markdown PDF Vision

    Turn a markdown file into a pdf:

    1lowdown -stms "$FILE".md | pdfroff -itk -mspdf > "$FILE".pdf

    Example: put this Makefile in a directory, rename it Makefile, then do:

    1make example
2make

    To give the document a title, put that title in the metadata:

    1sed -i "1 i---" "$FILE".md
2sed -i …

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