HDTV, DVD and DivX Video Playback Peculiarities
Since DeltaChrome graphics processor is based on a complex programmable Chromotion engine intended for video streams processing, we though it would be interesting to find out how greatly it can reduce the system CPU workload during video playback in different formats.
Of course, we were mostly interested in checking the situation with HDTV video, so let’s start here. This standard provides the highest quality video of all other standards today, because it supports resolutions up to 1920x1080. For a more illustrative comparison: the widely spread DVD format supports 720x576 in PAL and 720x480 in NTSC modes. Of course, HDTV video is much harder to decode and process than the regular DVD streams. This is exactly where Chromotion may be the right thing to help. However, if you want to take full advantage of the S3’s programmable engine, you should receive fully-fledged support from the developers of video playback software. Today we are going to find out if the advantages of S3 Chromotion engine will provide us with efficient HDTV playback. For our tests we downloaded two videos with 1920x1080 resolution and 8384Kbit/sec bitrate (you can download them from Microsoft web-site).
I should say that it would be incorrect to speak about the horizontal resolution in case of video playback by consumer electronic devices, because this parameter is not critical for TV-sets. The resolution in this case is defined as the number of displayed vertical lines. In our case there were 1080 of them. In case of video playback on a PC the horizontal resolution depends on the video format. If the screen sides ratio equals 4:3, the horizontal resolution equals 1440, and for 16:9 ratio – 1920 horizontal pixels. The first video used in our today’s test session was recorded in 4:3 format, and the second one – in 16:9 format.
Each of the two videos was about 2 minutes long. To pay both of them we used the regular Windows Media Player 9. When we played the HDTV videos the CPU utilization varied from 47% to 63% and no visual artifacts were revealed. If you took a closer look at the image, you could notice that it was a little grainy, which could be caused by the WMV format. Nevertheless, the image quality was just excellent and the colors bright and rich. When we installed a RADEON 9600 XT and then GeForce FX 5700 Ultra, the situation didn’t change and the CPU utilization remained the same. It means that the unique video processing abilities of S3 DeltaChrome do not work right now. At least it is true for the WMV format and Windows Media Player from Microsoft.
Now let’s see what happens to other formats. S3 Graphics provided us with a specially optimized InterVideo WinDVD 5 version. During the playback of the above mentioned videos, the CPU utilization stayed about 55% and all Chromotion video effects worked just fine, except Neon Forge. When we enabled Neon Forge the CPU utilization immediately grew up to 100% and the video playback started spurting forward. We observed the same effect when we enabled Deblocking Filter, although it doesn’t make much sense to apply this filter to HDTV video, because the quality of this video is high enough and doesn’t need this kind of additional processing.