Conference Paper
Rhythmic Music Codec: An MDCT-Based Music Codec with Onset-Localized Block Switching and Tempo-Synchronized Prediction
AES Show 2026 Nashville · Paper 43 · October 2026
Abstract
This paper presents the Rhythmic Music Codec (RMC), a novel audio codec that exploits the temporal structure in music. RMC builds upon a baseline codec based on the Modified Discrete Cosine Transform (MDCT) by
incorporating two complementary modules: transient-aware block switching and rhythmic prediction. A multi-layer transient detector identifies onsets and triggers a sequence of variable-length analysis/synthesis windows providing
enhanced time resolution in the proximity of each detected attack. A tempo-synchronized prediction module identifies rhythmically related regions in previously decoded audio and encodes the prediction residual only when
doing so reduces the coding cost. Subjective listening tests following the ITU-R BS.1116 recommendation compare the baseline codec, the block switching and prediction modules individually, and the complete RMC system. The
results demonstrate that the combined codec provides a statistically significant improvement in perceived audio quality over the baseline while incurring only a small, bounded increase in decoder complexity, with the added cost
concentrated in the encoder.
