Question / Help Completely new to OBS, have some questions

C

Count Von Blatt

New Member
Hi guys! I searched a lot but can't seem to find what I need, so might as well ask here.

I'm a director/filmmaker/pc enthusiast, worked in broadcast, I was on my way of buying cameras and a switcher for a TV show I do for a local TV network, but we realised maybe we could invest in a system that could also work for streaming and/or recording. I can't seem to find info on which components are more important that others for my needs.

We would have 3 HDMI cameras (can output 4K and HD, will mostly work in HD) and probably 1 or 2 graphics, stereo input.

We would like to be able to:
- Record the output of a 3 camera setup in prores or high quality codec (tv show scenario)
- Livestream for clients (concert/conference scenario)
- Livestream AND record (not necessarily prores but something better than h264)

I'd be building a custom PC for this, was thinking:
Ryzen 5 1600AF
32gb ram
RX580 8gb
NVME for OS
Blackmagic Decklink Quad or Magewell quad HDMI capture card

What do you guys think? Will I be able to pull something like this off?
 
You could get a cheap atem mini and setup a nas with fast wifi and send recording directly from cameras to NAS for queued encoding if needed, per source. If you have small distances, wifi can work but you'll need technical expertise to maximize effiency and good routines for control. Ryzen 5 isnt really a good pick when u can get ryzen 7 so cheap and doesnt make sense if your background is true.. Dont really like the rx580 choice either. You'll want a gpu that supports latest codecs and maximum features. If you were thinking a simple ryzen 5 would handle 3x 4k encoding and or even managment of the bandwidth requirements then you're quite the optimist. - wifi will only here benefit preview resolutions and possibly single source at the time. Wifi 6 goes to 10gpbs, almost, so its a desireable option if stability can be attained. Certainly removing need for cables is every streamers wish..

Btw with atem mini you can remove any capture cards if you can sacrifice a usb-c port with full usb 3 capabilities (preferrably 3.1+)

Lossless 720p from game source in my tests usually run about 3gbps with a 10gb lane, staking that up to 1080p we get to a rough 4.2 gbps. So in order to gain 4k we're talking very quickly dual 25gbe nics for wire transfer - ie 3x 4k sources lossless - not even going to bother checking the math on that.. So that's where you'll want some encoding to lower it from lossless as to be able to fit more sources in. Distance doesnt play too much of a role, except if going the sfp+ route.

Id at least go for the 3900x coupled with the fastest memory you can find and a motherboard with a 10gbe option to save on costs for an additional nic, which will also open up the option of addtional network cards that can be dedicated to NAS recording etc. IIRC both asus and asrock has such options. The question then becomes wait for x670 or current x570 options. I think x570 is good enough and does have the benefit of being a pure amd design. 3950x would be ideal with it's 16 cores and ideal for cpu encoding, even with SMT off, as a dedicated encoding box.
 
Hey vapeahoy, thanks for taking the time to chip in!

I forgot to mention that I want to be able to see a multiview screen and a pgm screen, which I could maybe record with an external recorder or see if I can record in OBS. That kinda takes out the ATEM minis because I can't have multiview, or if I do, I end up with a compressed pgm output recording.

As for the PC requirements, lets just say we need 1080p. No 4K. The ryzen 5/7 conundrum is something I keep an eye out on ebay everyday, we'll see what I can get, but you get the idea of kind of budget/pc power I'm getting at. You're saying "If you were thinking a simple ryzen 5 would handle 3x 4k encoding" but wouldn't I be only encoding one stream? the pgm output? Or does OBS have to process each video feed when inputted to the software? I thought the capture card did that. Again, really new at this.

Why so much CPU power? I remember doing a livestream with two HDMI cameras and one USB camera through a laptop two years ago, I didn't think there would be so much need for more processing power.
Also, what do you think I should look for in GPUs? Is architecture more important than ram amount? What about ram speed?
 
If you intend to only capture the output of whatever you stream, then however many cameras you have matter very little, as the bottle necks will be a bit different, ie we're then suddenly just talking about 1 source. In post production work one might want to edit whatever the 3 or X amount of cameras record and thus it's a completely different scenario. But since you lead on with 3 cameras alas.
I've used a single 1700 for 720p stream with a very custom ffmpeg encoding setup and it will crush x264 veryslow at medium setting, but around 60 more custom options. I will however stress that it will stress even the 8 cores. The good news is we have newer ryzen cpu's now with more l3 cache and better ram training enviroment, also helped by newer x470/x570 then the initial 1st gen. I also used a custom overclocked set of ram at 3466 cl14 with the fastest timings possible, a good deal further then the ryzen oc calc suggested, and i ran one time a stream 24 hours non stop without fail. It's a very impressive cpu. But i wouldnt even bother considering 6 cores, or less then 16 threads rather.

But attaining 1080p is out of the question for the 1700 i used, simply because even as powerful as it is, one will run into the problem of needing lookahead option to sustain smoothness of 1080p picture - made even worse with twitch's 6mbit limit. Tho i havent streamed in a long time so idk if thats still relevant - probably is, and it's certainly still an issue given one wants to have a stream thats watchable despite not ideal bandwidth conditions. Might work now tho with newer encoder and lots updates since, but i'm still fairly certain i would be at the very threshold.

Ie 1080p for 6mbit is just not worth it, 720p will be better quality and practically better in every way.
Of course everything is still relative, ie what i consider OK will be completely overkill for someone else and so on. However there is barely no difference in costs here so i dont see the point in the ryzen 5 at all, regardless.
If you're going for 1080p certainly i would not go lower then the 3700.

All of this is based on using the cpu in a dedicated streaming box. If you're going to do work or game at the same computer, it's the 3900x or gpu encoding.

I for one will just wait till the final iteration of am4 cpu's. An alternative option is getting a 1660 card, i think the super version had the better encoding support, but would double check that, and then doing latest nvidia encoder on that. Which should be fairly good and will less expensive then cpu encoding. It all depends on how quality enthusiast you are about it all and budget.

For cpu encoding ram can help quite a bit, especially since its ryzen. I've overclocked some samsung chips that default to 2666mhz cl19 to 3600cl16. So can be something to save there, but for most users 3200cl14, or 3200cl12 if can find them is the deal to get.

edit: that was a set of 8x samsung dimms, at simple dual chan it would be about 3600c14.
 
Last edited:
I don't understand, I need to have a 4000 computer to switch between 3 cams and record the output? How did people manage 2 years ago? Its a lot cheaper to buy the professional equipment. I must have asked the wrong questions. I'll read everything again and regroup.
 
For just switching between sources, you can find a decent hdmi/displayport switch on ebay. But you specifically said :

Count Von Blatt said:
Hi guys! I searched a lot but can't seem to find what I need, so might as well ask here.

I'm a director/filmmaker/pc enthusiast, worked in broadcast, ...
....
We would have 3 HDMI cameras (can output 4K and HD, will mostly work in HD) and probably 1 or 2 graphics, stereo input.

We would like to be able to:
- Record the output of a 3 camera setup in prores or high quality codec (tv show scenario)
...
I'd be building a custom PC for this, was thinking:
Ryzen 5 1600AF
32gb ram
RX580 8gb
Click to expand...

Which I initially took as you wanted to have full source recording for each and on location encoding to production production during a live broadcast. I simply have a lot of freetime at the moment due to obvious circumstances, and so responded as if you were serious.

Sorry about that, lol.
 
I'm relieved that I don't need that much of a computer, but I still wonder, what does each component have to do with each part of the process. Is there a wiki or something for dummies? I understand how computers work, how cameras work, how switchers work... but not how OBS works or what it needs for each scenario
 
There isn't a single source to learn everything no. And the book in theory is being rewritten every day with each new update here and there and with new hardware advancements, new possibilities open up. If you just want an easy setup you should just get a latest generation nvidia card and use nvidia encoder on that. If you want to have maximum control over picture, cpu encoding is still very much an option. GPU encoding is the easy option as you remove in part input lag from the encoding machine. If you want to do network stuff while in production you'll need to account for that. It's way too many things to try and cover in a random thread. Can work the whole life on it, and there will continue to be new things to talk about.

edit: figure out what your most chaotic video scenario would be on screen, and then do stress tests on that scenario to figure out optimal quality options while still maintaining stability. Most people dont care at all tho and hit stream and let it rip.
 
Thanks for your answers! I'll just get the PC running and try to borrow the quad hdmi capture card and test different scenarios... worst case scenario, I just use that computer for editing, which was gonna be its only use.

Thanks!
 
Count Von Blatt said:
Thanks for your answers! I'll just get the PC running and try to borrow the quad hdmi capture card and test different scenarios... worst case scenario, I just use that computer for editing, which was gonna be its only use.

Thanks!
Click to expand...

I like to use something I call "what would an idiot do?" testing. F.example, while starting a benchmark to benchmark computer, start another benchmark, and another one, and so on. Figure out where the system breaks. Thats for overclocking scenarios tho. But the principle remains the same for anthing else. How chaotic can the video picture be, and does it handle fast to slow etc transitions. If you do gpu encoding you practically dont have to worry about it for a seamless picture, alltho there are still tons of things one could do, for cpu encoding, the whole system matters, greatly. One of the benefits of cpu encoding is that it benefits from easily upgradable hardware and so you have control over that, and you can also take control over the software path - due to how opensource works. etc. Cpu encoding is a lot of work, but its also great to have that kind of control, alltho i certainly would not recommend it as it has a steep learning curve and the user will have to customize it to work for their systems. Where as with gpu encoding, if you have X card, you can know for certain almost that X settings will work greatly to almost 100% of the time for general streaming.
 
What do I have to look for, for GPU encoding? It sounds easier than CPU. Do I have to look for if it has support for encoding a certain codec or is it something else?
 
Just latest generation nvidia card with an encoding chip, which most of them got if not all now.. There are some differences in what chip is used and so u need to check you card pending on budget - what encoding chip it got and it that supports your needs. Amd isn't and in imo never has been an option for the simple reason they have never supported differences in refresh rates across I/O over your various monitors and or to and from capture card scenarios. Havent checked if they fixed it, not going to bother. amd got great cards generally tho.

NVENC - Wikipedia

en.wikipedia.org en.wikipedia.org
developer.nvidia.com

Video Encode and Decode Support Matrix

Find the related video encoding and decoding support for all NVIDIA GPU products.
developer.nvidia.com developer.nvidia.com
 
Thanks! I'll give it a read. I was thinking about AMD cards because they behave a lot better in hackintoshes (which I was thinking about building). But I'll see what middle ground I can find.
 
For a hackintosh the scenario might be different. I wouldnt really buy a card now tho, unless you just have to. It all depends on this situation now how long it will last, but i expect we'll get a crash of new stuff as things recouperate a bit. Amd is releasing new stuff but there's quite a delay on it. So not the ideal time to be buying anything imo. Then again, supporting the economy is is a good idea, so im still buying stuff, just no traditional performance items, rather upgrading network etc.
 
You must log in or register to reply here.
Back
Top