Design And Realization Of Ogg/Vorbis Decoder

With the development of multimedia technology, more and more audio compress standards such as WMA, APE, MP3 appear. Nowaday, MP3 is most popular in audio process domain, but Ogg/Vorbis get more and more attentions and favors of audio compress researchers because of its open-source and good compress performance, and we can believe it will become the substitute of MP3 in the future.The decoding process of Ogg/Vorbis standard is easy, it includes header decode, floor reconstruction, residual decode, IMDCT, windowing and so on. The topic of this thesis is the application of Ogg/Vorbis Decoder in DSP. According to Tremor Decoder (a fix-point decoder which Xiph.org provides), we wrote Ogg/Vorbis decode code using our own instruction set, and realized Ogg/Vorbis Decoder in FPGA.We designed several output methods for our Decoder and chose DMA interrupt method with 8 output buffer at last. The conclusion after some test is: our Ogg/Vorbis Decoder can decode 2-channels Ogg files which encoded with any sample rate and bit rate, and can get good real-time performance.Then, we improved the function of our Decoder with dual-core(CPU and DSP) communication, thus our OggA/brbis Decoder realized some basic functions such as play, pause, positioning, stop.