DVD/Multimedia Subsystem

Keyframe Interpolation

ATI has had a long tradition of top-quality multimedia and video acceleration. Their last generation product - the ATI Rage128 Pro - has earned some of the best overall scores in MadOnion's Video2000 benchmark.

While other designs may have better quality at the expense of performance, the truth is that no one's beat ATI in terms of raw video performance. So what did ATI's engineers come up with for the Radeon 256? Better performance. Better quality.

Full HDTV support

When it comes to DVD performance, the Rage128 is already at the top of its class. Offering both iDCT and hardware motion compensation, ATI has claimed successful DVD playback on Pentium 233MMX class machines (though I expect some stuttering in high-bitrate scenes.).

In short, there's not much to improve on the DVD portion of the chip. The new addition in the Radeon 256 is an improved MPEG-2 decoding engine which will allow it to support all 18 digital TV formats. The Rage128 supported a resolution of "720p," or 720 horizontal lines of resolution in a progressive scan format. The best way to think of this is to imagine a 1280x720 monitor running at 60Hz. This is pretty impressive considering the fact that DVD's have a maximum of 500 lines of resolution.

The Radeon 256 takes HDTV support a step further with full "1080i" support, or 1080 lines of resolution in an interlaced format. This is an interlaced 1920x1080- a higher quality image than most monitors can display! This can be more than four times as complex to process than DVD!

My monitor doesn't support that resolution, so why should I care?

That's what I thought at first - what good is supporting such high-resolution graphics if you're never going to see it anyway? Well, the ATI engineers thought about that as well and they've integrated a Y'PbPr output on the chip. (also known as component video) This means that the Radeon 256 can directly drive an HDTV or TV with component video. The component video of the Radeon 256 will be able to output at all 18 ATSC formats including 1080i and 720p.

So what does this mean in terms of quality? First, when ATI releases the HDTV tuner card "within the Radeon 256's product lifespan," the Radeon 256 will be able to upgrade HDTV-ready televisions to a full-fledged HDTV solution. Second, the Radeon 256 will now offer support for true progressive-scan DVD; this is something that's currently limited to $1000+ DVD stand-alone DVD players.

Deinterlacing

Most television programs are recorded in an interlaced video format. This means that although a television is updating 60 times per second, only half of the screen is updated each time. The odd lines are drawn, then the even lines, then the odd, and so on. Interlacing on a TV really isn't a problem at all - it's only an issue when you're trying to display interlaced video on your monitor.

It should come to know surprise to you that your monitor is a progressive scan device. That is, if you run your desktop at 1024x768 at 120Hz, then all 786,432 pixels are updated 120 times per second. What happens if you want to playback video that's encoded in an interlaced format such as TV show?

To have it show up on the monitor, you have to deinterlace the video somehow and convert it to a progressive scan image. Traditionally, there have only been two solutions: bob and weave.