The PC-DVD Guide -> Glossary

Before we can get into this guide, there are a few terms that you need to know. There is a more extensive glossary on this page, but it covers more things to do with DVD conversion (eg. to DivX, VCD, SVCD), than basic PC-DVD knowledge covered in this guide.

16:9 Enhanced - See Anamorphic Widescreen

5.1 - See Dolby Digital 5.1

AC-3 - See Dolby Digital 5.1

Anamorphic Widescreen - DVDs that are said to be anamorphic widescreen are enhanced for television sets that support 16:9 compression (eg. widescreen and most high-end TVs). Please refer to Chapter 6 for more information.

Aspect Ratio - The ratio of width versus height (eg. 16:9) - there are 3 main standard in use today, 4:3 (fullscreen - eg. analog TV broadcasts), 16:9 (or 1.85:1 - many new movies and digital TV use this ratio) and 2.35:1 (the standard cinema ratio). Please refer to Chapter 6 for more information.

Decoding - DVD video is encoded in a format where a large amount of video and audio can be stored in relative small space (also called Compression). The video encoding scheme used is MPEG-2 (Motion Picture Expert Group 2) and the audio encoding scheme used is either MPEG-2, DTS or the more common Dolby Digital AC3 (also known as Dolby Digital 5.1).

Dolby Digital 5.1 - A sound compression routine that compresses the 6 channel soundtrack from movies into a a single digital stream that occupies less space. The 6 channels are : front left, center, front right, rear right, rear left and a LFE channel for deep bass effects. The LFE channel is given the .1 rating, thus giving 5.1 channels of discrete CD-Quality audio.

DTS 5.1 - A competing format to Dolby Digital, which most regards as having better quality. Not all DVD players (either software, hardware, or standalone) can playback DTS audio tracks, and an external DTS decoder may be needed - all DTS DVDs will have a Dolby Digital soundtrack (either stereo or 5.1), so you should still be able to hear something with DTS DVDs. Also see Dolby Digital 5.1.

DVD-ROM drive - The device that actually read DVDs. This is the most basic requirement of any DVD related functions (eg. playing DVDs, ripping DVDs, converting DVDs), and there is no substitute for it. While the actual DVD media looks like CDs, they are actually very different in terms of physical properties (DVDs have more "pits" packed closer than CDs) - and this is why they require different types of lasers for reading.

Firmware - Software stored on semi-permanent/permanent memory on hardware, that can only be accessed by a firmware uploaded/flasher program. Firmware are usually basic software to control the basic functions of a hardware device (eg. the open/close "tray" function on DVD-ROM drives, region control).

Hardware Decoder - Uses a PCI decoder card to do the decoding, where the mathematical calculations required to decoder the DVD movie is done on the PCI card. This type of decoder is not heavily dependent on the CPU or the graphic/sound cards.

Pan and Scan - a 4:3 (see Aspect Ratio) movie that has been "converted" from a widescreen source. A 4:3 (almost square) area on the widescreen picture is taken (with the sides of the picture not visible), and this "square" pans from left depending on where the most important part of the image is. You often miss out on 1/3 to 1/2 of the picture with pan and scan movies.

Software Decoder - Uses "software" to decode a DVD movie. This basically tells the CPU to perform some mathematical calculations to decode the DVD movie file, without any serious help from the video card or the sound card. However, a suitable video card is required to be compatible with the type of software mode needed to draw the video on screen, which in this case is done in hardware overlays.

Macrovision - most DVD movies are copy protected to prevent you from copying it to VHS. Unfortunately, this may prevent playback of DVDs through your computer's TV-out, or distortion patterns when you try to watch a DVD through your computer's TV-out. For more information, please refer to DVD Digest's Macrovision-free Guide.

Regions - DVD movies are encoded in regions that will need to be matched up to the region of your decoder. For example, in the US, the region code is "1", and you will require a decoder that is set to this region ("1"). If you tried to play an Australian DVD (region "4") DVD in the same decoder above, you will get an error and the disc will not play. Most computer based decoder (either software or hardware) has the advantage of being able to change regions of the decoder by software, meaning that they are in essence, multi-region decoders. But you will also need your DVD-ROM drive to be multi-region or software region locked for a true multi-region system. If you DVD-ROM drive is hardware locked, then you cannot change the region with software. This is similar to Set-top based decoders (see above), which are usally hardware region locked too. However, if you are handy with a soldering iron, you can short circuit a connection in your set-top player to make it multi-region, but you risk voiding your warrantee. More detailed information on regions can be read in Chapter 6 and in DVD Digest's Complete Region-free Guide.

Set-top/Standalone Player - This is the type of player that you can connect straight to a TV-set, sort of like a VCR or a Laserdisc player.

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