Bad Apple for the GBA

Decided to try my hand at porting Bad Apple to the GBA. See it running here.

How it works

Compression

• Video is compressed as a variable number of 2 byte chunks for every frame. These chunks contain the number of times a color repeats and either a 0, 1, or 2, which represent black, grey, and white respectivley.
• Audio isn't compressed, but its sampling rate is halved and saved as headerless 8bit PCM.

Decompression

Decompressing the video on the fly can be taxing, especially on frames with a lot of detail. To prevent the frames from falling out of sync with the audio, a hardware interrupt is used on every frame to keep track of what the current frame is.

Building the code

To build this code, you'll need a Linux computer (BSD might work, probably not macOS though, even though its based on FreeBSD). Sorry Windows users, but I just cannot deal with the headaches of making a buildscript work on Windows. If you're on Windows and want to build this, your best bet is to use WSL/WSL2.

Dependencies

This project has a few dependencies:

• youtube-dl
• ffmpeg
• python
• make
• g++

In addition to those, you'll also need to install the DevkitARM toolchain and ensure that its in PATH.