DVD Players

A DVD player is a device that plays discs produced under both the DVD-Video and DVD-Audio technical standards, two different and incompatible standards.

Technical Details
A DVD player has to complete these tasks:

Read a DVD disc in ISO – UDF version 1.2 format
optionally decrypt the data with either CSS and/or Macrovision
read and obey the DVD's Regional lockout codes and display a warning if the player is not authorised to play the DVD
decode the MPEG-2 video stream with a maximum of 10 Mbit/s (peak) or 8 Mbit/s (continuous)
decode sound in MP2, PCM or AC-3 format and output (with optional AC-3 to stereo downsampling) on stereo connector, optical or electric digital connector
output a video signal, either an analog one (in NTSC, PAL or SECAM format) on the composite, S-Video, SCART, or component video connectors, or a digital one on the DVI or HDMI connectors
[edit] CD/DVD/RMVB playback
Additionally, most DVD players allow users to play audio CDs (CDDA, MP3, etc.) and Video CDs (VCD). A few include a home cinema decoder (i.e. Dolby Digital, Digital Theater Systems (DTS)). Some newer devices also play videos in the MPEG-4 ASP video compression format (such as DivX) popular in the Internet, as well as the RMVB video compression format.

Output
Most hardware DVD players have to be connected to a television set; there are also some small portable devices which have an LCD screen attached.

[edit] Portable DVD Player
Main article: Portable DVD Player
Portable DVD players that are capable of playing DVDs. Most have an LCD screen and stereo speakers and are usually powered by lithium ion batteries. Portable DVD players are often used for long road trips and travel.