Hardware DVD decoding

[Jaggu]

I have a All in Wonder 128 video card from ATI (AGP version). I see that the specifications say harware DVD playback. But there is no special connector from the DVD drive to the ATI card. How does the hardware decoding work?

Jaggu (a Newbie to Video)

 

[Workin']

The IDE (or SCSI) cable carries all the data off the DVD disc. DVD movies are just another kind of data file (.vob is the extension).

When the DVD player software opens the DVD data structure, it tells the hardware decoder on the video card to take over some functions that would normally be provided in the software and performed by your CPU - kind of like how a 3-D accelerated video card takes over some functions to render the output from certain programs.

The DVD drive doesn't need a special connection to the video card - DVD video isn't like audio CD's (which are decoded by a digital-to-analog converter which is part of the drive, hence the special cable from the drive to your soundcard).

Hope that helps.

 

[Mday]

the ATI video player, based on cinemaster, is the only program that can take advantage of the hardware IDCT decoding.

IDCT is the method by which mpeg compression\encoding for video work, and the Rage128 series of chips have onchip instructions to decode them.

one place you can start learning about mpeg is http://www.mpeg.org