Optimizing Audio Compression Through Entropy-Controlled Dithering

Abstract

This paper explores entropy-controlled dithering techniques in audio compression, examining the application of standard and modified TPDFs, combined with noise shaping and entropy-controlled parameters, across various audio contexts, including pitch, loudness, rhythm, and instrumentation variations. Perceptual quality metrics such as VISQOL and STOI were used to evaluate performance. The results demonstrate that TPDF-based dithering consistently outperforms RPDF, particularly under optimal alpha conditions, while highlighting performance variability based on signal characteristics. These findings suggest the situational appropriateness of using various TPDF distributions. This work emphasizes the trade-off between entropy and perceptual fidelity, offering insights into the potential of entropy-controlled dithering as a foundation for enhanced audio compression algorithms. A practical implementation as a Digital Audio Workstation plugin introduces customizable dithering controls, laying the groundwork for future advancements in audio compression algorithms.

Figures (15)

• Figure 1: Inputted sine wave with amplitude 1 (blue) overlaid by quantized sine wave to 2 bits (red).
• Figure 2: Quantized sinusoidal wave without dither applied.
• Figure 3: Quantized sinusoidal wave with dither applied.
• Figure 4: Rectangular Probability Density Function.
• Figure 5: (a) Triangular Probability Density Function (b) Modified Triangular Probability Density Function.