Avivo And Purevideo DVD Quality Enhancements
So now that we've explained the troublesome process of enabling DVD quality enhancements with Avivo and Purevideo, what do we get out of it?
To show you the answer to that, we use the HQV DVD video benchmark. This benchmark is simply a regular DVD comprised of different scenes that present visual problems for the DVD decoder. Points are awarded if the decoder can correct these problems so that the viewer does not see them.
We should note that these problems can be fixed with software as well as with hardware. Some DVD playing software will do a decent job of correcting certain problems without hardware acceleration. So we have benchmarked both the ATI and Geforce cards with and without hardware acceleration enabled to demonstrate what is corrected by the software, and what difference the hardware decoder makes.
DVD Quality Enhancement 1: De-interlacing
The standard for video is North America is called NTSC. With NTSC video, there are 30 frames a second. To complicate matters, each frame is made up of two separate "fields."
A single field of video is comprised of half of a screen. Not the top half or bottom half, but alternating lines (see image below).
In the subsequent field, the opposite half of the lines is updated, and so on. When these alternating lines are displayed, the result is called "interlaced" video. Here is a simple demonstration of how fields would look if you slowed them down:
Demonstration of video fields
NTSC video calls for 60 interlaced fields per second, or two fields per frame. At low, blurry resolutions like those that standard TVs offer, interlaced video doesn't look too bad. But on high-definition televisions and on your computer screen, this interlacing becomes very obvious. The good news is that it can be corrected with de-interlacing, if your hardware or software can deal with it.
The HQV benchmark has four tests to measure the effectiveness of de-interlacing on your DVD player: Color Bars, Jaggies 1, Jaggies 2 and Flag.
Color Bars test: out of 10 points
This test simply shows a pattern of lines and color bars. If the DVD player can show the smallest lines without flickering, it is successfully de-interlacing the image.
The HQV color bar test
Software: 10 points
Cyberlink's PowerDVD has a built in software de-interlacer that does a really good job of getting rid of flickering and interlacing artifacts. It does indeed merit its perfect 10 out of 10 score.
ATI Avivo: 10 points
Without hardware acceleration enabled, but the pulldown detection checkbox left disabled, the ATI cards blur the lines a bit and score a five. With pulldown detection enabled, they score a perfect 10.
Geforce Purevideo: 10 points
As long as hardware acceleration is enabled, Purevideo scores a perfect 10.