 Spectral band replication

Spectral Band Replication (SBR) is a technique used in audio coding and compression, particularly in the context of lossy compression formats like AAC (Advanced Audio Codec). The primary goal of SBR is to enhance the perceived audio quality while keeping the file size relatively small. ### How it Works: 1. **High-Frequency Extension**: SBR is primarily used to reconstruct high-frequency content that can be difficult to encode at lower bit rates.