MLow: Meta’s low bitrate audio codec

What this post added

This post introduces MLow, Meta's new low bitrate audio codec designed to improve real-time communication (RTC) quality, particularly for users on slow connections or low-end devices. MLow achieves two-times-better quality than Opus at 6kbps WB (POLQA MOS 3.9 vs 1.89) while maintaining 10 percent lower computational complexity. It utilizes a split-band encoding approach with advancements in excitation generation, parameter quantization, and coding schemes, building on CELP principles. MLow also enables more effective Forward Error Correction (FEC) strategies, improving audio quality in packet loss scenarios.