compressioning

MPEG-4 Natural Audio Features
Just as in MPEG-1 and MPEG-2, Audio compression is the core functionality of MPEG-4. However, the range of bit rates covered by MPEG-4 Audio and the compression ratio and sound quality have been improved much over previous systems and can be considered state of the art today. Besides this MPEG-4 has a lot additional new functionalities. Fraunhofer IIS provides technology supporting the following functions:
• Bit rate scalability (hierarchical coding) allows a bit stream to be parsed into bit streams of lower bit rate which still can be decoded into a meaningful signal. The bit stream parsing can occur either during transmission or in the decoder.
• Bandwidth scalability is a particular case of bit rate scalability, whereby part of a bit stream representing a part of the frequency spectrum can be discarded during transmission or decoding.
• Encoder complexity scalability allows encoders of different complexity to generate valid and m...