Home

Welcome to the bgbtech_misc wiki!

Mostly still familiarizing myself with all this.

BTIC1x Family Codecs:

• BTIC1G
  • Older/Simpler byte-oriented low-complexity incremental codec.
  • Main use case is streaming video from robots.
    • It is more intended for low complexity rather than bitrate or quality.
    • It is mostly intended for incremental video streaming from ARM-based robot controllers.
• BTIC1H
  • Intended as a reasonably low-complexity codec for fast encode/decode.
  • It isn't intended for the best possible bitrate or image quality.
    • It was originally mostly intended as a replacement for BTIC1G in the same basic use-case.
    • However, the design seems to also work passably for screen-capture and other things.
• BTIC4B
  • Similar in premise to BTIC1H, but uses 8x8 blocks.
  • This reduces per-block overhead, allowing for higher speeds.
  • General effects on Q/bpp have yet to be determined.

BTAC Audio Codecs

• BTAC1C
  • Modified MS-IMA-ADPCM
  • Generally fairly effective.
• BTAC2B
  • Possible fancier design.

Data Compression:

• BTLZA / BTLZH
  • An extended form of Deflate supporting larger windows and matches.
  • It is a backwards-compatible binary superset of Deflate.
  • It was intended as a compromise between Deflate and LZMA.
    • Speed closer to Deflate, but compression closer to LZMA.
    • Thus far mostly used in Huffman only mode (BTLZH).
    • Conceptually, which term is used depends on whether or not AC is used.
• FeLZ32
  • Speed oriented DWORD-based LZ77 format.
  • In my tests, gains faster speeds than LZ4 at the expense of slightly worse compression.
  • The cost to compression depends a bit on payload, generally with binary formats faring better.
  • Intended mostly for use-cases where encode/decode needs to happen quickly.