Once you've bought your Blu-ray player, it's worth familiarising yourself with the connections on the rear panel, as hooking up the wrong socket to your TV or AV receiver may prevent you from getting the best possible picture or sound quality.
The HDMI socket is to Blu-ray what John and Paul were to the Beatles. This all-digital connection can carry video and multichannel audio simultaneously, and without it you won't be able to watch hi-def pictures in all their glory (if at all). All Blu-ray decks come equipped with an HDMI output, but the confusing part is that there are different versions of the connection, which makes certain features available on some players but not on others.
Ideally, your deck should sport an HDMI 1.3 socket, which is the latest version of the standard. It supports bitstream output of Dolby True HD, DTS HD Master Audio, Dolby Digital Plus and DTS HD soundtracks, as well as Deep Colour and automatic audio/video synchronisation. But a word of warning - HD audio bitstream output and Deep Colour support are optional parts of the standard, which means that an HDMI 1.3 socket is no guarantee that a player offers these features. Examples of Blu-ray players with this type of socket that do offer these features include the Panasonic DMP-BD30 and the Samsung BD-P1400.
You'll find component video outputs on the vast majority of Blu-ray players, but although this analogue connection can support video resolutions of up to 1080p, the copy protection systems in many Blu-ray discs force the player to downscale the component output to SD as a safeguard against piracy. Therefore in most cases the only way to view Blu-ray discs in their native resolution is to use an HDMI connection.
Multichannel Analogue Audio Outputs
Players with built-in audio decoders provide these sockets so that people whose receivers don't sport HDMI inputs can listen to HD audio soundtracks, the difference being that the audio is transferred in analogue form. You can also listen to decoded Dolby Digital and DTS soundtracks through these sockets.
Digital Audio Outputs
The regular digital coaxial and optical outputs on Blu-ray players lack the bandwidth needed to transfer HD audio soundtracks, but you can still use them to transfer regular Dolby Digital or DTS bitstreams to your receiver. When playing any of the HD audio formats the player extracts the ‘core' 5.1 channel stream and outputs it from the digital audio socket, often at a slightly higher bitrate than a regular Dolby Digital or DTS soundtrack.
This connection is a key part of the BD Live profile (see ‘Profiles' on page 1) as it allows you to connect to the Internet and access extra content. But if you find an Ethernet port on a non-BD Live player, don't get too excited - chances are it can only be used to update the player's firmware.