google/brotli · GitHub

https://github.com/google/brotli/

Brotli is a generic-purpose lossless compression algorithm that compresses data using a combination of a modern variant of the LZ77 algorithm, Huffman coding and 2nd order context modeling, with a compression ratio comparable to the best currently available general-purpose compression methods. It is similar in speed with deflate but offers more dense compression.

GitHub - google/zopfli: Zopfli Compression Algorithm is a compression library programmed in C to perform very good, but slow, deflate or zlib compression.

https://github.com/google/zopfli

Zopfli Compression Algorithm is a compression library programmed in C to perform very good, but slow, deflate or zlib compression.

Google Open Source Blog: Introducing Brotli: a new compression algorithm for the internet

http://google-opensource.blogspot.jp/2015/09/introducing-brotli-new-compression.html

While Zopfli is Deflate-compatible, Brotli is a whole new data format. This new format allows us to get 20–26% higher compression ratios over Zopfli.

Code Excited Linear Prediction - Wikipedia

https://ja.wikipedia.org/wiki/Code_Excited_Linear_Prediction

Code Excited Linear Prediction（CELP、セルプ）は、1985年に米AT&Tの M.R. Schroeder と B.S. Atal が提案した音声符号化アルゴリズム。

携帯電話の音声圧縮のベースとなっているアルゴリズムらしい。