Question / Help Game Capture Cards, Shadow Play and OBS?

[Plitz]

Hi, i am planning to change my r9 270x against an GTX 970, which supports shadow play. At the same time i plan to buy a capute card (AVerMedia).

But before i do so i wanted to ask you guys if this makes any sense. Does the Capture Card profit from Shadow Play? Do i need Shadow Play if i have a Capture Card? Do i need the Capture Card if i have Shadow Play? And how can OBS work together with all these Services.

If my Stream/PC can profit from the Capture Card, how do i know which one to get? There are so many of them, with all the same specifications ... yet the pricerange is huge! What is the difference?


Last Question regarding the capture Card: Is it okay to use the Capture Card in my Gaming Rig or should i use a second PC for capturing and streaming? Does OBS still use pretty much of my CPU when i have the Capture Card installed?

 

[dodgepong]

Capture cards do pretty much nothing if all you're doing is capturing the same PC that you're encoding on. They do not improve performance at all, and should not be thought of as devices that improve performance. If you're just streaming a PC, then getting a second machine dedicated to encoding would obviously ease the load on the first PC.

Thus, using NVENC and a capture card are unrelated, as each one accomplishes different functions.

 

[Plitz]

On the Page of AVerMedia they are telling, that this card is taking the part of encoding the video. Does this function just doesnt work with OBS? they are specifically stating that it is working with xsplit.

They are specifically stating, that there is no need for a second PC anymore.

Do they tell lies?
Is it only working with specific software?
Or are they at least a bit right?

Would Shadowplay take away load from my CPU or is it just affecting the GPU Load ... or ... does it like the Capturecard only work with other Software?

 

[dodgepong]

The Live Gamer HD has a built-in encoder that OBS cannot use, since I don't believe their SDK is public. Even if it were available, it's a pretty terrible encoder, so it's not recommended. But they push that aspect of the capture card pretty hard to the point where people think that simply having it installed will help their performance, but it won't.

NVENC will alleviate CPU load, yes. It uses a hardware encoder on the GPU, so it doesn't affect GPU load either. However, all other things equal, it will produce lower quality video than x264.

Also, I think you're confused on the difference between NVENC and Shadowplay. NVENC is the hardware encoder (which OBS can also use) and Shadowplay is an nVidia program that can use NVENC to encode gameplay. OBS does not use Shadowplay, OBS uses NVENC.

 

[Plitz]

Okay ... are there any Capture Cards available that produce good quality and are usable with OBS?

i tried using the streaming feature with my AMD card.... it totaly looked like shit. NVENC any better? In the end i want a picture as clear as possible, can the NVENC push out a picture at least as good as "veryfast" or even better? Or does it look worse?

 

[dodgepong]

What do you actually need a capture card for? Are you capturing an external device, or do you intend to make a 2-PC setup?

As for VCE and NVENC, it largely depends on your bit rate. Both encoders are more designed to be used for local recording only, and thus they do a lot better when run at high bit rates. As for streaming, since you will be limited on bit rate, x264 will give better quality at a given bit rate.

 

[Plitz]

best would be if there was a way to source out the cpu load to another device on the same computer. but if there is nothing else available i am able to install another mid-range i5 just for the stream. since this is more like an better office pc there shouldnt be any load on the graphics card ... and as low as possible load on the cpu.

 

[dodgepong]

If you're just trying to offload the CPU, then getting a capture card will be useless unless you get a second PC dedicated to encoding. Otherwise, you can try QuickSync or NVENC and see how that turns out.

 

[Plitz]

You are awesome :) 100€ less spend on useless things thanks to you :) i will try quicksync as soon as possible. Thanks.

 

[davethejackal]

I have to correct the mod here. Here's how I have used a capture card to offload stuff on my old AMD gaming system: you get OBS to project its output onto the capture card, as if it's projecting to a monitor. You then only use OBS in preview mode, with encoding disabled and use the capture card to do the encoding, pushing data out through your gaming PC.

 

[dodgepong]

In that case you're using the capture card as a dedicated encoder, and not all capture cards have a dedicated encoder. Most people expect to capture their actual content with a capture card, and then import their content into OBS, and use OBS to do the encoding/streaming and expect that to somehow reduce load. In your case, you're not importing the capture card into OBS, you're exporting OBS to the capture card. It's an interesting workaround, to be sure, but not a catch-all solution, and generally not what people have in mind when then they are asking this question.

 

[davethejackal]

In that case you're using the capture card as a dedicated encoder, and not all capture cards have a dedicated encoder. Most people expect to capture their actual content with a capture card, and then import their content into OBS, and use OBS to do the encoding/streaming and expect that to somehow reduce load. In your case, you're not importing the capture card into OBS, you're exporting OBS to the capture card. It's an interesting workaround, to be sure, but not a catch-all solution, and generally not what people have in mind when then they are asking this question.

Perhaps they don't do it because it's not viable. At the very least you need to fix audio monitoring, since without being able to hear OBS's full mix, audio monitoring is virtually worthless. if you fix that, then it becomes usable in the above fashion.

I didn't think of the idea, a few streamers use it. I originally heard about it from Lirik. The workaround is to feed my soundcard output into my line in or some such, using an audio lead, since i could send line in to the capture card.