Question / Help Maximum bitrate in OBS Studio - not streaming service dependent

opticitch

New Member
Some background on me: I am a technical expert turned A/V expert through my job in enterprise IT moving to enterprise IT for a large live theater. I am good with tech and networking and currently stream online using a two computer setup, NDI stream, capture cards, network audio... with gigabit home internet and a studio I have set up at a commercial address. I am familiar with live broadcast for TV and web for live shows through this work and have a practiced workflow and specialized hardware and software for it.

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Question:
What is the maximum bitrate available in OBS Studio for streaming or recording? I am not talking about streaming ability of different services. I am talking about the ability of the program. Does Wirecast do more? (I do not want to use Wirecast, but I need a point of reference with reasons below)

If it is dependent on the hardware, is there a chart I can use to calculate that?
Would Mac vs. Windows matter?
Can OBS (or any similar program) even handle... say a... 50mbps recording to go well over the maximum I'm receiving and working with? (see below)

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Reasoning and scope:
I am asking because I have been requested to provide an absurd network throughput for work with a streaming service I bid to work with. The network throughput requested is many times the maximum of the source video and assets they provide. It approaches the RAW video bitrates I used to see from studio cameras a couple years ago, although they are providing compressed video feeds from DSLRs and other compressed video recording sent through further compression over a third party server. I have also been given a number of raster images and mp3 audio files as show assets.

I will be running two upstreams (one A/V feed from a remote studio in on my downstream to be sent upstream with live management by either my home or commercial studio, and one audio connection out/in for communication with a remote broadcast station that could be done on cell data), but they are still requesting well above the theoretical maximum bitrate of the data ingest for my upstream part (≈30mbps if I was just recording to local drives). All of this will be done, by their request, in OBS or Wirestream, preferably OBS.

I have the network ability to handle a multi-Gb/s symmetric connection through a dedicated fiber line and enterprise hardware from the studio, or an upstream speed above the maximum plus a wide safety margin for network congestion from home, but I have been informed that my home network speed is still too slow. I do not want to argue with a project manager, but I feel the request is absurd and even harmful to their own service. The extra data would put unnecessary strain on their servers to process and export to people watching on mobile devices at only a few mb/s with no increase in quality over that much lower value of ≈30mbps . I have offered to match their formatting for easier transcoding or to reduce losses in converting and resizing, but they still request the high speed for what amounts to a Discord video call level of visual and audio requirements.

Due to privacy and NDA concerns with the work bid, I can only say that the requested throughput is somewhere well over (let's say) 15 times that of Twitch's maximum bitrate for a 1080/60p stream or even a Netflix 4k video.

I'd rather do this work from home as the studio has a slight risk of scheduling conflicts and my home studio can be more easily customized for the project without affecting others' work.

Thank you for reading my novel. Expect it on shelves Q2 2021...
 

BigYuckFou

Member
Just took a look and it will allow me to set mine to a max of 9999999 Kbps

If I had to guess the software might do that? just do an internal network test? stream from one PC to another using NDI possibly?
 

opticitch

New Member
Unfortunately NDI does not appear to be affected by anything I do, and I can't find any user-definable settings for it. I did what you suggested, feeling like an idiot for not just doing that myself lol, but I cannot get mine as high as yours (limited by the interface). What I have gotten it to should be fine as a demo for them, however.

I wish I had a server to test on in house that would accept rtmp or virtualcam output... maybe I'll run one tomorrow. This 200mbps recording test is at least giving me a way to show them that there is no discernible difference past a certain bitrate.

I am actually surprised that OBS doesn't have a limit in that regard. What is it putting in the file different than at 50? at 10? Oh well...

I'm running it with standard test patterns to send them comparisons.

(Oops. I was recording a test through this whole response and I now have a 2 GB video file...)
 

megpoid0

New Member
OBS Studio doesn't have an upper limit on bit rates (or at least nothing you're realistically going to hit), but some video encoders do. NVENC, for example, will fail to start at around 240-250 Mbps, that's a limitation imposed by NVIDIA. You can, however, use CQP when streaming over LAN or other reliable / not congested connections, allowing much higher bit rates.

NDI disobeys everything in Settings > Output, it's only affected by Settings > Video and its own settings.

You can also go YUV444 with certain video encoders, improving color accuracy slightly, at the cost of doubling the bit rate and denying yourself the performance benefits of hardware decoding.
 

opticitch

New Member
Thanks for the note on max bitrate for NVENC. Is there a way to use CQP or YUV444 in OBS? I don't see anything in the settings for recording output or under advanced. I do see the attached image under "Advanced"

I can't imagine YUV444 being important for their needs, but thank you for giving me some more technical details to compare and send to the company as a "You don't need this because..."

Even if I wasn't receiving an mp4 (or lesser, possibly) stream for the main video source, their servers are still dropping it to h.264 or 265 for viewing by the audience from some basic assets.

I produced a set of test recordings from 6mbps up to a reasonable limit for sending through my cloud storage (my <2min test videos were getting over 1GB each) with 4K test patterns to show that quality stops increasing for their purpose around 10mbps. I wish I knew more about h.264 to know what extra data is being stored at that point... Maybe next week :)

You can also go YUV444 with certain video encoders, improving color accuracy slightly, at the cost of doubling the bit rate and denying yourself the performance benefits of hardware decoding.
 

Attachments

TryHD

Member
OBS does not have any problems with outputting high bitrates and with NVENC you most likely hit the limit of your storage before you hit other limits.
 

opticitch

New Member
That's awesome, TryHD. Yeah, I'm not going near that, yet. I do have an SSD on the main with a gigabit file server externally, but there's no way I'm dealing with that... I have gotten some clarification on need from the company, but it still does not make sense. It is outside the scope of OBS however, and more on the data links to the broadcast stations and production houses.

Is there a way to mark this question closed?

Also, megpoid0, thanks for the note on YUV444 and I444 in settings along with the NVIDIA link. I should also clarify myself that my test images are 4K tests, but the company is only using 560/30p at a maximum broadcast (as of now). I ran the demos with 1080/30p output from 6mbps up to a very, very high number that I was surprised still worked... and sent the output to the company for comparison. I had to open them in Photoshop at a very high magnification on a variety of monitors and display settings to spot the differences visually rather than only programmatically.
 
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