gmod-bad-apple

Setup Instructions

1. Clone repository
2. Run cargo run -- "media/frames.zip" 30 "media/audio.wav" "media/output.bin" 40 30 10
3. Create e2 bad_apple from bad_apple.e2
4. In bad_apple e2, import video data
5. Place E2 into world and wire to a digital screen

Technical Details

The video data is encoded into base64 and uploaded as code along side of the decoder e2.

• Video data
  • Format - 1 byte
  • Width - 1 byte
  • Height - 1 byte
  • Frames - 2 bytes
  • FPS - 1 byte
  • Video stream

Formats

Every video format encodes the difference between frames.
The reason the difference is used is because setting every pixel every frame is VERY expensive.
Even though the video data is smaller if we use the frames themselves instead of the difference, the E2 would easily hit tick quota while setting the pixels.

• RleSimple (1)
  • The difference between frames is encoded.
  • Flip flops between off/on with lengths.
    • Eg. 3 1 2 4 1 4 1 will decode to

    ___X
    __XX
    XX_X
    XXX_
    

• Quadtree (2)
  • The difference between frames is encoded.
  • Splits to sub-trees or leafs, Leafs encode color information.
    • 0 = Split
    • 1 = Leaf (Next bit is if pixel is off/on)
    • Must be leaf if width & height is 1.
    • Each sub-tree/leaf is evaluated from depth first.
      • (Top left, top right, bottom left, bottom right)
    • Eg. 0b010111100110 will decode to

      __XX
      __XX
      XX_X
      XXX_
      

• RleSimple2 (3)
  • RleSimple but lengths may be encoded into many bytes instead of 1.

Format Table (60x45 @ 7fps)

Format	Size (Base64)	Total CPU Usage (μs)
RleSimple	304KiB	515,026
Quadtree	177KiB	1,170,762
RleSimple2	291KiB	436,832