vlac: A lossless audio codec for voice, written in Rust

说明与用途

vlac 是一个为 16 kHz 单声道语音音频设计的无损编解码器，使用 Order‑4 LPC 预测器和带训练字典的 Zstandard。它保证 100 % 位精确，支持 WebAssembly 编译，并可训练域特定字典，虽然在一般语音音频上比 FLAC 大 8 %。

问题

Need a lossless codec that preserves 16kHz mono voice audio with domain‑specific compression and WebAssembly support.

结果

vlac achieves 8 % larger files than FLAC on general voice audio but guarantees bit‑perfect output and supports domain‑specific dictionary training and WebAssembly compilation.

工作流

• Predict next sample using previous three samples (Order‑4 LPC).
• ZigZag encode the residuals.
• Split residuals into High and Low bytes for efficient Zstandard compression of zero‑padded High bytes.
• Compress the split residuals with Zstandard using trained dictionaries.

证据

I built vlac, a lossless audio codec designed specifically for 16kHz mono voice audio.

来源

On a 10.75-second voice memo (337 KB WAV): Original WAV: 337 KB, FLAC (ffmpeg default): 151 KB, vlac: 163 KB

来源

vlac currently produces files 8% larger than FLAC on general voice audio. However, it is 100% bit-perfect (verified via MD5 hash on the raw PCM data) and compiles to WebAssembly.

来源