November 25, 2020  

1 min 23 s  

Code

The Worst One-Liner

I have an external HDD with all my old gameplay footage I want to keep for my archive.

However, It’s all raw from the recording software and therefore HUGE.

The Solution

Use ffmpeg to encode the videos.

ffmpeg -i game.mp4 ~/Videos/Gameplay/game.mp4

But, use my AMD Graphics Card.

ffmpeg -hwaccel vaapi -hwaccel_output_format vaapi -vaapi_device /dev/dri/renderD128 -i GAME.mp4 -c:v h264_vaapi -profile:v high -level 41 -c:a copy -b 15000k GAME.mp4

Automate it all

I don’t want to type this command for every file, that’d take years.

List the mp4 files.

$ find . -type f -name "*.mp4" -print0

• -type f Find only files.
• -name Match this name.
• -print0 Use a NULL character instead of a newline.

Prepare the output file name.

Here’s how I turned the input path into the filename with cut and the delimiter (-d) argument.

For example ./Battlefield1/EpicMoment001.mp4 into EpicMoment001.mp4

$ cut -d \ -f 3

Note: The above command takes into consideration the depth of the folder structure.

Using xargs

Using xargs we can take the input from the find command and execute a statement for every entry.

$ xargs -I {} -0 sh -c "..."

• -I {} Map this input parameter to this sequence of characters
• -0 Terminate entries by a NULL character, usefull when you have filenames with spaces.
• sh -c "..." Execute this command for each instance.

The final monstrosity!

# Working from the current directory: /media/usb/GAMEPLAY
$ find . -type f -name "*.mp4" -print0 | xargs -I {} -0 sh -c \
    "ffmpeg -hwaccel vaapi -hwaccel_output_format vaapi -vaapi_device /dev/dri/renderD128 \
    -i \"{}\" -c:v h264_vaapi -profile:v high -level 41 -c:a copy -b 15000k** \
    \"/home/arran/Videos/Gameplay/{} | cut -d / -f 3`\""

I’ve Won.. But at what cost?

This was my first endevour with ffmpeg and I’m sure it won’t be the last, time to look for a better solution to bulk operations.