GFX card video decoding

[Zarxrax]

I'm looking to build a new system, and I'm curious about the features I've been hearing about in graphics cards these days for accelerating video decoding.

I'm not really interested in playing a lot of 3d games, so I really just want a card that can take some of the load of decoding h.264 video off of my cpu.

How exactly does acceleration work? Do I have to use a special player, or will it work with any directshow-based player? Does it work with players that are not based on directshow, such as VLC? Can it help out when I'm doing something like reading an H.264 video through avisynth?

Are there any cards that can help out with encoding video?

[Turtleggjp]

I just bought a new 2400Pro card to test this stuff out. It should be waiting for me at home today. I'll let you know what I find out with it.

I'll take a guess and say that VLC media player will not be able to use it for acceleration, unless they rewrite its decoders for that. As far as AVI Synth decoding, maybe if there is a direct show filter that can use the acceleration, DirectShowSource might work. For encoding video, same thing as VLC media player: Not unless your favorite encoder is rewritten for it. However, I believe that ATi software has supposedly had support for hardware assited encoding of video, but it would be through their own software, which is anyone's guess as to how good it compares in quality to the other ones more commonly used. Might be good for quick jobs where it just needs to get done, and maximum quality is not an issue.

Matt

EDIT: Update. Got the card in, and so far H.264 acceleration looks great! Single digit CPU usage for a High Def trailer of "The Departed" video only, and that's with a 1.6GHz Sempron! I downloaded this clip in an .EVO container, which PowerDVD 7.3 refuses to play (may be just playing audio) but if I pull out the video track using EVODemux, it plays it flawlessly. I have two other .EVO trailers (Serenity and Chronicles of Riddick), both with VC-1 video. PowerDVD will play these and I get both sound and video, but the video is choppy, and CPU usage is at 100%. My guess is that PowerDVD 7.3 doesn't know how to use the new 2000 series Radeon's VC-1 acceleration, but hopefully there is a newer version of it that will. I am about to try H.264 acceleration on one of my HD encodes using x264.

EDIT2: No go on just about every other h.264 clip I tried, all I get is a black screen. I guess the Departed trailer was a fluke (still works though). If I disable hardware acceleration, I get the picture correctly, but it is choppy due to the poor Sempron not being able to keep up. I will try to find an update to PowerDVD 7.3 now. Oh, and PowerDVD 7.3 doesn't like my graphics card drivers for the new card, so it stops legit HD-DVD playback after a few seconds. :mad: The latest advisor gives most stuff (including the drivers) a green light, and it only says that I should probably upgrade my memory (512MB) and it is unsure about my Sempron.

EDIT3: Downloaded a patch for PowerDVD (from Cyberlink), and now legit HD-DVD playback works. However, now I am getting downscaling! (picture does not fill my screen when I go full screen, looks to be about 960x540). Before I go whining to the AACS or whatever though, I remind myself that my card is only a 2400 Pro, and I know that they seem to emphasize 1080p playback with the 2600 series cards. Perhaps PowerDVD is doing this because it knows that my card can't do full screen playback. I even tried connecting it to my TV via HDCP (which the advisor says is working), but still get downscaling. I also noticed that for some reason, CPU usage is about the same now when playing HD-DVDs whether video acceleration is turned on or not. So far, the only clip to show a real benefit from the acceleration is that Departed Trailer. The other two VC-1 trailers play ok in their native .EVO containers (still downscaled though), but they look terrible if I try to play the demuxed VC-1 stream by itself (blocky, choppy, but full screen!). Even with the update I still get a black screen on my x264 encodes with acceleration, and correct but choppy (but not too bad) playback with it off. So for now, I continue to remain unimpressed by all this.

[CruNcher]

The Black Screen, is because the file you trying to playback is incompatible (virtualy all H.264 clips that where muxed with Mp4box 0.4.3 won't playback with Cyberlinks Decoder and active PureVideo 1/2) you have to remux it with the latest Dev Mp4box 0.4.5 then it will work with Cyberlinks Decoder and Hardware Accelleration same for .MKVs that where muxed from those incompatible .MP4 files.
see http://forum.doom9.org/showthread.php?p=1023991#post1023991

[Turtleggjp]

A little update.

I took CruNcher's advice and re-demuxed my AVC AVI and tried the raw stream on PowerDVD tonight. No more black screen :), but despite single digit CPU usage with my 1.6 GHz Sempron :cool:, playback is definitely choppy :(. In fact, it actually looks smoother with acceleration turned off, even though that causes the CPU to redline. At least it is playing full screen, and doesn't seem to have any blocking issues.

So my conclusion is that the 2600 series has 1080p in the specs for a reason, the 2400 just can't do it. I see that Gigabyte is supposed to be coming out with a fanless 2600Pro card soon, so as soon as I can get my hands on one of those, I'll update on how well it works.

Matt

[Turtleggjp]

Another Update:

I got a 2600Pro card today, however this seemed to improve only one thing: Raw VC-1 stream playback. Playback of the two trailers' demuxed VC-1 streams now seems to work perfectly. However, I still have the problem of downscaling with PowerDVD :mad: and now I can't get my x264 encodes to work again with acceleration, I am once again getting a black screen. I guess I will now focus on trying to rip my HD-DVDs and see if I can get PowerDVD to accelerate them some other way.

Anxiously awaiting open source software capable of playing .EVO files, as PowerDVD continues to fail miserably. I see that Dolby Digital Plus is starting to become supported in open source players. Hopefully, the rest of the needed knowledge will follow soon!

Matt