Thus, to fit video and movie data into smaller spaces for movie; DVDs, HDTV broadcasts and DSS satellite systems, MPEG compression is used.Pod casting is a term evolved by fusing digital music players (Pod from I-Pod) transmission (or broadcasting). The MP3 system enables a 30-megabyte sound file from a CD to be compressed to 3 megabytes and stored in an MP3 disc. 44,100 samples per second, 16 bits per sample and two channels (for stereo sound) are required to store music on a CD. About 10 million bytes (megabytes) of data per minute of music are stored on a CD and for a three-minute song 30 megabytes of data are needed. In Pod casting programmes the participants hold an interactive session of chatting, playing songs, etc and convert the recording into a digital audio file. It makes no difference to the sound quality and on downloading an MP3 file it plays as well as the original file.
It is mere conversion of different formats to make the process of downloading that much easier.In a compact disc (CD) the sound quality is superior as musical sounds are recorded on it by turning them into digits.. Anybody who has tried to download files on the Internet would understand that 30 megabytes is a massive quantum of memory space and using a modem for the purpose of Internet connectivity, 30 megabytes of data could take several hours to download.
A subsystem that compresses sound is called MPEG Audio Layer-3. Pod casters mostly patronize the MP3 format. It is also possible to download an MP3 file and stretch it back to the original size for the purpose of recording it on a writable CD that could be played on a CD player that cannot read MP3 files. For the purpose of recording/storing video data, MPEG (Moving Picture Experts Group) has created China custom precision die casting parts for sale systems of compression