Introduction

Christmas came early this year courtesy of FedEx and NVIDIA. I came home Tuesday morning to see an unlabeled brown box outside my door -- no markings other than a FedEx label. What was inside certainly wasn’t plain:

What is PureVideo HD?

From a marketing perspective, “PureVideo HD” is a great idea. The name captures the ultimate goal of the technology, makes for a great logo, and provides easy recognition for the public. It’s a great brand-name. What’s frustrating is that NVIDIA assigns that term to anything and everything that’s video-related. When talking about “PureVideo HD” on the GeForce 6 and 7 platform, we’re really talking about several different things, both hardware and software. (ATI is just as guilty in calling everything AVIVO).

Programmable PureVideo Processor

Every GeForce 6 and 7 with PureVideo (excluding the AGP versions of the 6800 Ultra/GT, and 6100) has a dedicated programmable video processing unit (VPU) on the physical chip. This programmable VPU is separate from the other parts of the GeForce that deal with video (like the scaler) and is also separate from the GPU shader part of the chip. It’s like having a dual-core CPU – one core is the regular GPU, and another core is a completely different VPU or thinking about the Vector Units in the Sony Emotion Engine in the PS2.

Although NVIDIA does not provide specific details about the underlying architecture of PureVideo, our best analysis suggests that the GeForce’s video processing pipeline involves several elements :

1. Fully-programmable VPU (H.264 decode, VC-1 decode, some deinterlacing)
   
2. GPU Pixel/Vertex shaders (some deinterlacing, noise reduction, sharpening)
   
3. Fixed-function video processing elements (video scaler, HDCP, MPEG-2 IDCT)
   
4. Software (Bitstream processing, H.264 IDCT)