MPEG is an encoding and compression system for digital multimedia content defined by the Motion Pictures Expert Group (MPEG). MPEG-2 extends the basic MPEG system to provide compression support for TV quality transmission of digital video. To understand why video compression is so important, one has to consider the vast bandwidth required to transmit uncompressed digital TV pictures.
Phase Alternate Line (PAL) is the analogue TV transmission standard used in the UK, and throughout many parts of the world. An uncompressed PAL TV picture requires a massive 216 Mbps, far beyond the capacity of most radio frequency links. The U.S. uses an analogue TV system called NTSC. This system provides less precise color information, and a different frame rate. An uncompressed NTSC signal requires slightly less transmission capacity at 168 Mbps. The situation becomes much more acute, when one realizes that high definition TV is just around the corner. A High Definition TV (HDTV) picture requires a raw bandwidth exceeding 1 Gbps (1000 Mbps).
MPEG-2 provides a way to compress this digital video signal to a manageable bit rate. Because the MPEG-2 standard provides good compression using standard algorithms, it has become the standard for digital TV. It has the following features:
- Video compression which is backwards compatible with MPEG-1
- Full-screen interlaced and/or progressive video (for TV and Computer displays)
- Enhanced audio coding (high quality, mono, stereo, and other audio features)
- Transport multiplexing (combining different MPEG streams in a single transmission stream)
- Other services (GUI, interaction, encryption, data transmission, etc)
DVD Ripper: Rip and convert DVD movies to popular video format like mp4, avi, mov, mkv, wmv, mpeg, mpeg-1, mpeg-2, mpeg-4, etc. for playback on iPhone, iPad, iPod, Samsung, HTC, etc.