l the standards specify the format of the data fields output from an MP3 encoder, and the operation of the decoders. Different vendors are therefore free to enhance the quality of audio encoding, SO long as a standard decoder can replay the encoded audio. This ensures that any MP3 player can play back an audio recording by another vendor's MP3 encoder. Table 5.5 shows a list of commonly used lossless audio compression standards and Table 5.6 gives a list of lossy compression standards. A comprehensive list of all audio codecs can be found in the literature [18, 19, 20, 21, 22]. Table 5.5 Lossless compression standards Lossless audio codec Application Bit rate Standard Storage/playback 1411 kbps IEC 60908 Storage/playback 50-60% of CD Apple Open Source Storage/playback 50-60% of CD XIPH.ORG Open Format Broadband Telecommunications Technologies and Management Table 5.6 Lossy compression standards Lossy audio codec Application Bit rate (kbps) Standard MP3 (MPEG-1 Storage/playback/ 32-320 ISO/IEC 11172-3 ISO/ and MPEG-2) streaming IEC 13818-3 AAC (MPEG-2 Storage/playback/ 32-320 ISO/IEC 13818-7 ISO/ and MPEG-4) streaming IEC 14496-3 Vorbis Storage/playback/ 45-500 XIPH.ORG Open Format streaming Windows media Storage/playback/ 24-768 Microsoft Proprietary audio (WMA) streaming Case Study 5.3: iTunes The MP3 technology was developed at the German company Fraunhofer-Gesellshaft, and their first German patent was issued in 1989. The technology was integrated into the MPEG-1 standard in 1992 and published a year later. MP3 system's high compression capability and relatively high quality of the reproduced audio presented a credible audio recording and playing alternative to the CD standard. Software prod- ucts were soon developed and the first MP3 music and portable MP3 players appeared in the market in 1999 [23]. However, major music producers did not sell music in the MP3 format because of file copying and difficulty of digital rights management (DRM). While MP3 files sharing on platforms such as Napster and later on KaZ