An Overview of Ogg Vorbis
Created at 12:34 AM 1/18/2007
Montnemery, Erik, and Johannes Sandvall. 2004. Ogg/Vorbis in embedded systems. Master Thesis, Department of Electroscience, Lunds Universitet.
A brief introduction of the encoding and decoding algorithm, without much details. Mainly focus on DSP based decoder implementation and optimization, i.e., how to reduce the memory and CPU usage. IMDCT is replaced by the more DSP friendly FFT algorithm. Provided with a list of useful references which can be used as a start point for futher study.
Foundation, Xiph.org. 2004. Vorbis I specification.
A complete specification of Vorbis I format, mostly on the decoding side. A must-read document for Vorbis developer.
Zolzer, U. 1997. Digital audio signal processing: Wiley.
[Chapter 9: Data Compression] Generic lossy data compression codec based on subband coding and psychoacoustic models. Block diagram that explain the procedure of encoding and decoding. Important concepts: Psychoacoustic coding, critical bands and bandwidths, Absolute threshold, Masking threshold, Spectral Flatness Measure (SFM), tonality index and masking index, Masking within and across critical bands, Signal-to-mask ratio, Pseudo-QMF filter bank, Polyphase/MDCT hybrid filter bank (in MP3). Introduction of Psychoacoustic Model 1 that used in MPEG I and II. Detailed procedure of computing the signal-to-mask ratio. A very brief introduction of Dynamic Bit Allocation and Coding.
Rominski, A., and Z. Ciota. 2003. Compression of wideband sound for multimedia application.
General discussing about MPEG and Vorbis compression technology, and speech compression technologies, without technical details.