<Li> DVD players cannot play Blu - ray discs . However, most Blu - ray players are "backwards compatible" and they will play DVDs . </Li> <P> Additionally, most DVD players allow users to play audio CDs (CD - DA, 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 . </P> <P> Most hardware DVD players have to be connected to a television; there are portable devices which have an attached LCD screen and stereo speakers . Portable DVD players are often used for long road trips and travel . They often have a plug for the 12 volt power jack in cars . Some models have two screens, so that two people in the back seat can both watch the movie . Other portable DVD players have a single screen that opens up like a laptop computer screen . </P> <P> Due to multiple audio (and video) output devices, there are many outputs on a DVD player, such as an RCA jack, component outputs, and an HDMI output . Consumers may become confused with how to connect a player to a TV or amplifier . Most systems include an optional digital audio connector for this task, which is then paired with a similar input on the amplifier . The physical connection is typically RCA connectors or TOSLINK, which transmits a S / PDIF stream carrying either uncompressed digital audio (PCM) or the original compressed audio data (Dolby Digital, DTS, MPEG audio) to be decoded by the audio equipment . </P>

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