The second point of hardware supplemented DVD decoding the Rage 128 Pro brings to the table is its support for Inverse Discrete Cosine Transform (ICDT) in hardware. ICDT is just a part of the MPEG2 decoding process and by offloading it onto the graphics card from the CPU, your CPU is freed up to perform other tasks. Not only does this help users with slower CPUs but it also makes multitasking more of a reality while playing a DVD on your computer.

While we're still not at the point where you can run a primarily software decoded MPEG2/DVD stream and play a game of Quake 3 in the background, offloading ICDT onto your graphics chip does help keep the frame rate up during the decoding process even while you surf the net or launch Word.

The third and final point on the Rage 128 Pro's DVD decoding capabilities is its ability to perform the DVD subpicture feature in hardware. DVD subpicture is a very commonly used feature that allows you to display graphics over video such as subtitles or menu features, both of which are commonly used in DVD movies.

In order to place a subpicture over a DVD stream, the subpicture (a compressed bitmap) is decompressed and outputted to the screen on the fly. While this isn't the most CPU intensive part of playing back a DVD, it does contribute to some of the CPU load associated with DVD playback where there is excessive use of the subpicture feature. Performing this in hardware allows for the decompression of the subpicture on the fly as it sends it to the DAC for output. This only reduces memory bandwidth and CPU utilization by a small percentage but it does help.

Although this sounds great on paper, the fact of the matter is that this feature won't really be used all that much since subpictures are not commonly used in most DVD playback situations. However, it is a nice feature to have and that tops off the trio of hardware DVD acceleration features the Rage 128 Pro supports.

ATI Rage Theater

theater.jpg (13681 bytes)The retail version of the Rage Fury Pro (based on the Rage 128 Pro chipset) will ship with the new Rage Theater. The beauty of the Rage Theater is that the chip itself doesn't add much of a manufacturing cost to the card and offers quite a bit in return. What exactly does the Rage Theater offer?

Texture Compression & DVD What does the Rage Theater offer?

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