VDPAU - 8400 GS - Which one?

[Vorgus]

Originally Posted by roger1818

Thanks for all the responses. It is nice to know the ASUS has the G98 chip.

I should better explain what my needs are. I will be using it in my MythTV HTPC for playing programs recorded with an ATSC tuner so I am less concerned about H.264 and more concerned about MPEG-2. Although the streams are in HD, I will be downconverting them to SD as I don't have an HDTV yet, so I need the card to have TV-OUT (for S-VIDEO). When I get an HDTV, I can always upgrade my video card at that time.

Are there any fanless GF 210 cards with TV-OUT? All the ones I have seen have an HDMI connector instead.

I was also looking at a 9400 and a 9500 (both by Sparkle), but was told they actually aren't as good as the 8400 (and looking at the link provided by gradinaruvasile, it seems true as they only support feature set A).

Any other recommendations? Thanks again!

Right now I am only using the 8400 on atsc and it is down converting to SD. My tv has RGB in, so that is what I am using. And I can tell you, the asus 8400gs silent is too slow. It requires careful settings and still gets droped frames, looses A/V sync, gets stuck in some kind of video studder with no audio (fixable by chaning chanels). I use 1/2 spastal because one of the channels has more problems at full. I would not recommend this card. Also, think ahead. You may want to do more latter, even just add a dvd to play movies.

btw, it doesn't matter that yuo are down converting it. It's the source that matters. If it can't play h264 video then it doesn't matter if it's going to 1080p or TV-out, it's still h264. The card still has to handle the data before it down converts it as far as I know

[roger1818]

Originally Posted by Vorgus

Right now I am only using the 8400 on atsc and it is down converting to SD. My tv has RGB in, so that is what I am using. And I can tell you, the asus 8400gs silent is too slow. It requires careful settings and still gets droped frames, looses A/V sync, gets stuck in some kind of video studder with no audio (fixable by chaning chanels). I use 1/2 spastal because one of the channels has more problems at full. I would not recommend this card. Also, think ahead. You may want to do more latter, even just add a dvd to play movies.

Thanks for the advice! May I ask what PC you are using? Although the video card may be doing all the MPEG decoding, there may be other bottlenecks with a PC that is underpowered.

[cehoyos]

Originally Posted by gradinaruvasile

I dont know exactly the theory behind this, bit i have a Quadro NVS 135M on my laptop that supports set A and i have a 8200 on an ASUS M2N78-VM mobo that supports set B - and i can tell you that the 135M doesnt played all movies the 8200 did.

Could you point me to a sample? I am curious (and I don't think this is a known issue).

And i havent seen a single movie that works on the 135M and doesnt on the 8200...

Just try any H264 video that is 1024 pixels wide...

Carl Eugen

[primerib]

Originally Posted by roger1818

Aren't all ATSC broadcasts currently encoded in MPEG-2

Nope. You may want to make sure the broadcasts you plan on using are in fact mpeg2 before you make your purchase.

[roger1818]

Originally Posted by cehoyos

Just try any H264 video that is 1024 pixels wide...

Where would someone find such a video? It isn't a standard resolution for television in North America. Is it in Europe?

[roger1818]

Originally Posted by primerib

Nope. You may want to make sure the broadcasts you plan on using are in fact mpeg2 before you make your purchase.

Really? Do you know of any stations in North America that broadcast over the air with H.264? In any event it would be a non-issue, since all the valid resolutions in the ATSC standard are supported by the G98 chip.

[Vorgus]

Originally Posted by roger1818

Thanks for the advice! May I ask what PC you are using? Although the video card may be doing all the MPEG decoding, there may be other bottlenecks with a PC that is underpowered.

Athlon64 x2 4200Mhz. Uses very low pcu but I do have to set the speed step trip down form 95% to 50% or raid rsync just about kills video because at the lowest setting the bus speed is also reduced. The default 95% seems to be too high for most things. But at 50% it doesn't take much to kick it out of idle.

It does handle the mpeg2 stream in soft mode better then the gpu, but it runs the cores at 80-90%+ so not much head room left.

[Vorgus]

Originally Posted by primerib

Nope. You may want to make sure the broadcasts you plan on using are in fact mpeg2 before you make your purchase.

That would not be the US ATSC because in the US, ATSC is mpeg2. That is the standard set by the feds.

[roger1818]

Originally Posted by Vorgus

Athlon64 x2 4200Mhz. Uses very low pcu but I do have to set the speed step trip down form 95% to 50% or raid rsync just about kills video because at the lowest setting the bus speed is also reduced. The default 95% seems to be too high for most things. But at 50% it doesn't take much to kick it out of idle.

I have read about this problem. Apperently some AMD processors throttle the bus speed along with the CPU clock. They say to play with it to find a value that works well for you.

It does handle the mpeg2 stream in soft mode better then the gpu, but it runs the cores at 80-90%+ so not much head room left.

Hmm. I wonder if the issue is the 8400 doesn't have enough horse power to both decode the HD MPEG stream and down convert it to SD. Have you tried it on a 1080p display to see if you get the same problems?

One question, you say in your previous post that you are using 1/2 spatial de-interlacing. Why bother de-interlacing at all if you are down converting to SD (which is interlaced)?

[primerib]

Originally Posted by Vorgus

That would not be the US ATSC because in the US, ATSC is mpeg2. That is the standard set by the feds.

The ATSC standard supports both mpeg2 and mpeg4 (ITU-T H.264). Also, the FCC regulates how communications are established, but not how those signals are compressed. You will never see the FCC enforcing the use of an audio or video codec. That's not the function of the FCC and they don't have the power to do it anyways.

[roger1818]

Originally Posted by primerib

The ATSC standard supports both mpeg2 and mpeg4 (ITU-T H.264).

H.264 was only added in 2008 so to the best of my knowledge no TVs or set top boxes support it. For that reason alone, I can't imagine any broadcasters using it anytime soon, unless it is for mobile DTV, which requires a special decoder anyway..

[primerib]

It's not like it was kept a secret til the day it was added. It was common knowledge for a very long time before that. As a matter of fact, once it became blatantly obvious there was a high demand for hd content, neglecting to include h264 would've been idiotic.

All that aside, you should have a look at the following thread titled VDPAU testing tool. The results to tons of video cards have been posted there and it should help you figure out what best suits your needs.