Fast and Strong Burrows Wheeler Model
BRC is a very careful implementation of non-sequential move to front coding, the encoder is fully vectorized and decoder is partially vectorized.
BRC acheives compression rates on par with QLFC when paired with an order-0 entropy coder, and BRC can operate in parallel via OpenMP.
Here's some numbers from BRC on the enwik9.bwt test file, tests were run on an i7-7700HQ @ 3.5Ghz.
Note: time to compress via fpaqc and FSE (32KB blocks) is not included, these are purely timings of the BRC transform itself.
| Implementation | Encode speed | Decode speed | Compressed size (via fpaqc) | Compressed size (via FSE) |
|---|---|---|---|---|
| BRC4_AVX 16-threads | 483 MB/s | 548 MB/s | 168,556,196 bytes | 178,988,019 bytes |
| BRC4_AVX 8-threads | 456 MB/s | 486 MB/s | 168,556,196 bytes | 178,988,019 bytes |
| BRC4_AVX 4-threads | 303 MB/s | 316 MB/s | 168,556,196 bytes | 178,988,019 bytes |
| BRC4_AVX 1-thread | 99 MB/s | 108 MB/s | 168,556,196 bytes | 178,988,019 bytes |