There's a new release candidate of OBS Studio out with a VAAPI video encoder on Linux

It also includes my fix for name collisions with multiple webcams of the same model \o/

Does OBS use ffmpeg as a library, or it calls ffmpeg binary itself?


Last edited by Shmerl on 10 Feb 2019 at 2:38 am UTC

Does OBS use ffmpeg as a library, or it calls ffmpeg binary itself?

I think the install instructions ask you to ensure that ffmpeg is installed, so I'd assume the latter.

erm, It already had it, it's what I use for hardware encoding with AMD



Last edited by pete910 on 10 Feb 2019 at 10:06 am UTC

erm, It already had it, it's what I use for hardware encoding with AMD


I think it's been available as a standalone patch for a while. On Debian Sid I have not had access to VAAPI but I'm thrilled it's finally coming. Maybe your distro has been applying the patch on their OBS releases?


Last edited by Brisse on 10 Feb 2019 at 11:04 am UTC

erm, It already had it, it's what I use for hardware encoding with AMD


There have been special builds out there with it as it was merged a while ago but it is only now in an official release, well candidate anyway.

The beaut of the AUR :P

Thinking about it iirc its Gloriouseggrols build as its called obs-studio-vaapi

The beaut of the AUR :P

Thinking about it iirc its Gloriouseggrols build as its called obs-studio-vaapi

That would make sense since they're the one who did the patch to OBS from what I remember.

Ooo, VAAPI sounds great! I didn't know it was coming. Although, game capture was one of the reasons I upgraded my CPU last year, so I already don't feel it anymore.

I'm more excited about the audio features (especially multitrack, whatever that means exactly, and a built in limiter). Due to the lack of any audio plug-in support we are pretty much limited to the built in effects unless you go to great length and try to get OBS to work nicely with external effects (JACK, PolypAudio).

I'm not too familiar with the VAAPI details. Is it not detrimental to the performance of the GPU for games? Is the encoding quality on par with CPU encoding?

The release notes don't mention any bug fixes, so it's hard to say what the feature vs. fix balance looks like. I'd rather have them fix their bugs and improve their codebase than add features. Try running OBS in Valgrind if you are up for a little shock.

;)

https://github.com/obsproject/obs-studio/commit/a64ae11bce8ed9a7c8f1deba3338f77595dba903

;)

https://github.com/obsproject/obs-studio/commit/a64ae11bce8ed9a7c8f1deba3338f77595dba903

You're a star :)

Now if only they would fix the bug where OBS doesn't create an output file.

;)

https://github.com/obsproject/obs-studio/commit/a64ae11bce8ed9a7c8f1deba3338f77595dba903

You're a star :)

I'd of said Glorious but hey :P

Now if only they would fix the bug where OBS doesn't create an output file.

Is this under certain conditions? Never came across this myself

Now if only they would fix the bug where OBS doesn't create an output file.

Have you reported this on the OBS forums or on Discord? This tends to be an edge case, and the more edge cases we know about, the more of them we can fix. It definitely shouldn't happen.

While we're here, has anyone else had an issue with recording in OBS where every video has a 1-2 second freeze at some-point that happens only once? I seem to see it in almost every longer recording I make.

I'm not too familiar with the VAAPI details. Is it not detrimental to the performance of the GPU for games? Is the encoding quality on par with CPU encoding?

GPU's have fixed function blocks specifically for encoding and decoding video. This is a part of the GPU that normally just sits there and does nothing while you are gaming. The performance loss while gaming and encoding video at the same time is therefore insignificant.

Yes, the quality is usually slightly worse than x264 running on a CPU, but at the same time it can be a hundred times faster which makes it very useful for some use cases, and it's great for those without powerful 8+ core CPU's. Even for those with a powerful CPU, there are cases where you might consider hardware accelerated encoding, such as when recording locally and you aren't constrained by bitrate. Something like 4k@60fps can be extremely taxing even on a high end CPU, but a GPU that supports it won't even break a sweat.


Last edited by Brisse on 11 Feb 2019 at 2:58 am UTC

This one is pretty awesome on Intel CPUs, their integrated GPUs does a fairly good job and the offloading of the CPU is very nice.

For intel iGPU a thing to note is that (in debian/testing at least) the open source drivers (i965-va-driver) do not fully support this but rather you need the non-free package i965-va-driver-shaders that also includes encode shaders. Or at least that was the case about two months ago.

(I'm on a Intel NUC7i5, which means Intel Iris Plus Graphics 640 (GT3e))

So why is it called "Oh, BS!" ?

I'm not too familiar with the VAAPI details. Is it not detrimental to the performance of the GPU for games? Is the encoding quality on par with CPU encoding?

GPU's have fixed function blocks specifically for encoding and decoding video. This is a part of the GPU that normally just sits there and does nothing while you are gaming. The performance loss while gaming and encoding video at the same time is therefore insignificant.

Yes, the quality is usually slightly worse than x264 running on a CPU, but at the same time it can be a hundred times faster which makes it very useful for some use cases, and it's great for those without powerful 8+ core CPU's. Even for those with a powerful CPU, there are cases where you might consider hardware accelerated encoding, such as when recording locally and you aren't constrained by bitrate. Something like 4k@60fps can be extremely taxing even on a high end CPU, but a GPU that supports it won't even break a sweat.

Thanks, but isn't GPU bandwidth also a consideration?