OBS Studio Gets a New Renderer

281 pointsposted 18 hours ago
by aizk

61 Comments

MBCook

10 hours ago

Great article. The description of how they handle shaders is just bonkers to me.

Is that really what you’d have to go through to have a working system with plugin shaders from 3rd parties on multiple backends? Or is mostly the result of time and trying to keep backwards compatibility with existing plugins?

Telling external devs “Write a copy in every shader language” would certainly be easier for the core team but that’s obviously undesirable.

delusional

9 hours ago

Transpiling shaders is what most game engines have done for a decade now. Everybody thinks it's stupid in that field as well, but there is no viable alternative.

ZiiS

3 hours ago

I think it was the most game engines once they adopted Direct 3D 8; so over two decades now.

JSR_FDED

15 hours ago

The submitted title buries the lede. It should be:

“OBS Studio Gets A New Renderer: How OBS Adopted Metal”

RobotToaster

14 hours ago

Also Mac only, since non Mac users won't have a clue what metal means in this context.

smcnally

11 hours ago

“Mac-only” was disappointing to read, but OBS’ render performance has been fine on macos and linux even with older hardware. James Webb calls anything heavier than helium “metal.”

mariusmg

8 hours ago

>James Webb calls anything heavier than helium “metal.”

And i call it great music.

MBCook

10 hours ago

Well Metal is the limitation there.

But they’ve clearly learned a lot that will help in the future with other modern APIs like DX12 or Vulcan.

monster_truck

9 hours ago

It actually wasn't, though.

That's besides the point though, the OS has been trash for realtime encoding for over a decade now. At the very least you have to write a script to repeatedly renice the process back to the top when it tries to protect you from the excessive thermal load lmao

robert_foss

7 hours ago

This quite clearly shows the cost of Apple preferring to build a software ecosystem moat, than using the Vulkan API which every other OS supports.

Vulkan support was introduced in OBS Studio 25.0 in March 2020, 5.5 years ago.

jdboyd

6 hours ago

Metal does pre date Vulkan, and some people consider it easier to use.

badsectoracula

5 hours ago

While Metal might be easier to use, i'm pretty sure it is still easier to have to worry about Vulkan alone than Vulkan+Metal. And Metal predating Vulkan is really only of concern to code that existed before Vulkan was made available (which wasn't that much).

brnt

2 hours ago

Mantle predates either, and Vulkan is based on Mantle.

stephen_g

3 hours ago

As if nobody else ever did that (like Microsoft with DirectX, and almost every single games console)?

ayi

9 hours ago

I'm no expert on topic. So, I maybe understood only 5% of what I read but I wish we had more posts like that. Announcements without any technical details sounds like marketing pieces.

Venn1

15 hours ago

I’m more excited about the upcoming support for VST3, but this is still welcome news. It is far easier than getting hardware encoding working with Rockchip SoCs on Linux.

andrekandre

14 hours ago

  > Metal takes Direct3D's object-oriented approach one step further by combining it with the more "verbal" API design common in Objective-C and Swift in an attempt to provide a more intuitive and easier API for app developers to use (and not just game developers) and to further motivate those to integrate more 3D and general GPU functionality into their apps. 
slightly off-topic perhaps, but i find it amazing that an os-level 3d graphics api can be built in such a dynamic language as objective-c; i think it really goes to show how much optimization put in `objc_msgSend()`... it does a lot of heavy lifting in the whole os.

Rohansi

14 hours ago

Modern graphics APIs minimize the number of graphics API calls vs. OpenGL and similar. Vulkan/Metal/DirectX 12 will have you pass command buffers with many commands in them instead of separate API calls for everything.

jasonwatkinspdx

10 hours ago

It's been possible for quite some time.

In the early 2000's there was a book on using Direct3D from C# that was pretty influential as far as changing people's assumption that you couldn't do high performance graphics in a GC'd language. In the end a lot of the ideas overlap with what c/c++ gamedevs do, like structuring everything around fixed sized tables allocated at load time and then minimal dynamic memory usage within the frame loop. The same concepts can apply at the graphics API level. Minimize any dynamic language overhead by dispatching work in batches that reference preallocated buffers. That gets the language runtime largely out of the way.

monster_truck

9 hours ago

No, it doesn't. You won't find it used much if at all at these levels of the OS. Once you get past cocoa and friends it's restricted subsets of C++ (IOKit for example)

pjmlp

6 hours ago

Yes it does, see NeXTSTEP, even the drivers were written in Objective-C.

adamnemecek

13 hours ago

There is a Metal Obj-C API, Metal implementation is C++.

almostgotcaught

11 hours ago

No it's not - the compiler for MSL is of course C++ because it's LLVM but the runtime is absolutely written in objc (there weren't even C++ bindings until recently).

adamnemecek

7 hours ago

No, I mean what is inside the Objective-C objects. Essentially everything on macOS has an Objective-C API but is implemented using C++. Have you ever noticed the ".cxx_destruct" method on like all objects?

What you are talking about are C++ wrappers around Metal Objective-C API. Yes, it is weird as they are going C++ -> Objective-C -> C++. Why not go directly? Because Apple does not ship C++ systems frameworks.

The term is Objective-C++.

leecommamichael

10 hours ago

I hope Modern GPU APIs are just a stepping stone to something simpler. OpenGL is loved and hated; and I have grown to love it after using the new stuff.

zdw

14 hours ago

I wonder how this improves performance on older Intel macs with a Metal-compatible GPUs, or if it's really a M-series only improvement.

stephen_g

8 hours ago

It says in passing As the Metal backend is only supported on Apple Silicon devices, GPU and CPU share the same memory in the part talking about the differences between the Direct3D and Metal render pipelines.

Not sure why though, because Metal 3 is still supported on a bunch of Intel Macs...

dwoldrich

15 hours ago

Was considering building a streaming rig around a Mac Mini. I wonder if with these performance enhancements, that will work for me?

keyle

15 hours ago

Highly depends on what you're streaming. If you stream arcade 2D games of the past, or software development, it should be perfectly fine.

AAA titles with newer graphics, well, you can always send a capture the PC with the nvidia card's screen through a capture card.

Back in my days of streaming, macOS was no option, cca. 2017. Today I'd do it with any M processor mac without a second thought.

KronisLV

5 hours ago

I actually used an M1 MacBook Air for encoding/compositing by sending the video/audio sources over from my main PC with DistroAV (LAN).

Worked reasonably well (you can send camera/VTuber output and captured video from game and any overlays separately, or just use the setup in a similar way to a capture card and run ONLY the game on the gaming PC and everything else on the Mac), but added some complexity to it all.

A beefy Nvidia GPU would make that setup not necessary, unless you want to directly play games on the Mac.

stephen_g

8 hours ago

Streaming video from camera? In general the newer Mac Minis in general were fine already just because the M-series chips are very fast, but hopefully this should make it much more efficient

caseyf7

9 hours ago

Apple should dedicate some resources to making this successful. Metal could use more wins outside of Apple itself.

__mharrison__

16 hours ago

Sadly, it breaks my scene with a PIP camera with a mask...

ChrisMarshallNY

13 hours ago

Well, to be fair, they say it's an "experimental" version, so they would probably appreciate a bug report.

keyle

15 hours ago

An obvious regression, you hope they'll get it fixed soon.

snvzz

16 hours ago

That is actually sad. It is such basic scene.

I hope the next version actually works in some facility.

29athrowaway

16 hours ago

If you are

- recording your screen but not streaming

- you are not customizing what goes into your screen

Then use something else. GPU screen recorder has a lower overhead and produces much smoother recordings: https://git.dec05eba.com/gpu-screen-recorder/about/

aizk

15 hours ago

Looks neat but seems like a complete hassle to get up and running and maintain, unless if your goal is to learn how screen recorders work.

purple-dragon

15 hours ago

The linked post is about a new Metal-based renderer for OBS Studio on MacOS. The software you linked is for Linux.

zamadatix

15 hours ago

I think the point extends well beyond the specific app/OS example though, even though the article talks to macOS exclusively. For macOS and Windows there are built in tools which offer direct recording functionality. To trigger on macOS Command+Shift+5 (or launch it via QuickTime as jasonlotito noted), on Windows Win+Shift+S. Both of these utilize the same OS APIs OBS Studio uses to get the screen content, but they skip the step of needing a renderer at all.

GSimon

14 hours ago

You need to install a 3rd party software Blackhole to even get desktop audio for screen recording with QuickTime. After about an hour of troubleshooting settings I gave up and used OBS, esp since I was in a public space at the time and the Blackhole config disabled my headphones and for a moment you could hear a loud YouTube tutorial playing through my Mac speakers. Also the shortcut to stop screen recording on QuickTime sucks, it’s like CMD+CTRL+ESC and you need to have it memorized because there’s no “Stop Recording” button option

lelandfe

13 hours ago

> get desktop audio for screen recording with QuickTime

A famously missing macOS feature. Loopback is yonder: https://rogueamoeba.com/loopback/

> the shortcut to stop screen recording on QuickTime sucks, it’s like CMD+CTRL+ESC

I just stop it from the menu bar, then on the resultant video press Cmd-T (trim) to lop off that footage.

ramses0

14 hours ago

It shows up in the notification area bar (top) as an ambiguous circle with a square in it.

spike021

14 hours ago

I've had a lot of issues using the QuickTime screen recorder, especially when it comes to recording from an iOS simulator for app/game development and needing to produce preview videos.

koakuma-chan

15 hours ago

NVIDIA has a "lower overhead" screen recorder, no? It's alt + f9 or something. AFAIK It's supposed to be optimized, because they own the stack and all. It's probably only on Windows though.

ycombinete

9 hours ago

If all you need is screen recording, as per your parent, and you're on windows the default screenshot tool (Win + Shift + S) does screen recording.

mcny

13 hours ago

Does anyone know if AMD 8845HS with 780M graphics (running fedora) can into this? Ideally very low system resources used, I only have 16GB RAM, also ideally very little storage space used, one or two frames per second is enough, ideally should compress even more if nothing has changed in the screen for a while, also ideally should create a new file every eight hours or so.

gooberman

3 hours ago

It should work yes. Fedora by default disables hardware accelerated video encoding but if you use flatpak versions of software (in this case the flatpak version of gpu screen recorder) then it should work. Even 12 year old gpus work.

Lower framerate doesn't really decrease video size because of how videos work, but you can set bitrate quality for the recorded video to reduce the video quality a bit to decrease the size.

jasonlotito

15 hours ago

Why not just use quicktime?

Edit: I think you might have skipped reading the post. It's about OBS on MacOS. Where quicktime exists. Your suggestion seems geared toward Linux.

minimaxir

15 hours ago

QuickTime cannot record system audio output without shenanigans.

jasonlotito

15 hours ago

Yep, if you want to do something more than screen recording, just screen recording won't work. Nor will the OP's comment.

stavros

15 hours ago

This is great, thanks!

zeeeeeebo

8 hours ago

now all macOS streamers need is games!

jdboyd

6 hours ago

Not all streamers are game streamers, and not all obs users are streamers. I installed on all of my workstations for its screen capture and virtual camera features.

maxlin

12 hours ago

Hope they'll fix the obvious bugs like CPU use going to 60% doing nothing after restore from hibernation next

daviddever23box

an hour ago

It's never "doing nothing" - you just need more visibility into your running tasks.

Turning off nearly everything iCloud- or Spotlight-related is a pretty good start; disable network access and you may find even more pearls of wisdom.