Question / Help further info upload speed vs bitrate

#1
Hi there

First post :) Good to be here in the world of OBS, very impressive software!

I live in South Africa, so internet is a bit of a problem here. However, I would still like to stream some of my games. More specifically HoN.

I have read a number of guides on setting up OBS, and also visited the http://obsproject.com/estimator

I have a downlink of 8128 kbps and uplink of 1024 kbps. Note : My ISP limits my downlink to 4096 kbps but it does/can spike quite high up to 8128 kbps on a regular basis.

I have i5 2500k with 8GB RAM and ATI 6950

estimator spat out the following :

Use CBR for improved stream stability
Recommended max bitrate: 680
Recommended buffer size: 408
I have read in various places that one cannot use the full uplink capacity for obvious reasons. Some guides say that you can dedicate 50% of your uplink speed to your video bitrate while others say up to 80%. Can someone please give me an idea of what I should be using?

Another question I have is the audio bitrate. AAC vs MP3. I assume that MP3 (compressed) will be better, but take more CPU to convert on the fly. Would MP3 be the best option in my case? Seeing as I have plenty of CPU but limited uplink speed?

Im open to any other tips/suggestions.

Many thanks for the assistance
 
#2
First off, AAC is better than MP3. It compresses better and has better quality at the same bitrate. Which is why it is default.

Now, as far as your bandwidth question goes -- http://www.testmy.net/upload -- Make sure to pick a test server that is near the streaming server you would be streaming to. To get an accurate idea of what your connection is capable of to that location.
 
#3
Kharay said:
First off, AAC is better than MP3. It compresses better and has better quality at the same bitrate. Which is why it is default.

Now, as far as your bandwidth question goes -- http://www.testmy.net/upload -- Make sure to pick a test server that is near the streaming server you would be streaming to. To get an accurate idea of what your connection is capable of to that location.
many thanks for that. and here I thought MP3 was better. I will stick with AAC then. For gaming purposed, 96 kbps should be enough?

I tested to the NL server. This is the server I have selected in OBS, as it gives me the best latency and least line jitter.

Upload speed is around 800 Kbps. That is to the testmy.net testing server, but I know for certain that I can sustain a continuous upload speed of 100K/sec. I have Netlimiter 3 installed so I watch it a lot.

Bearing this in mind, you think I should go with AAC 96kbps and a 480p stream with a bit rate of 680kbps?

I think I will be able to sustain that on my connection. Im worried its going to look crap though. Wish there were some test streams that I could see the different resolutions (480p vs 720p etc etc) along with the different bit rates.

:)
 
#4
TwoSugarsZA said:
Bearing this in mind, you think I should go with AAC 96kbps and a 480p stream with a bit rate of 680kbps?
That seems like a very reasonable starting point. And given the content (a MOBA), I think you could just stick with 24 or 30 FPS.
 
#5
Kharay said:
TwoSugarsZA said:
Bearing this in mind, you think I should go with AAC 96kbps and a 480p stream with a bit rate of 680kbps?
That seems like a very reasonable starting point. And given the content (a MOBA), I think you could just stick with 24 or 30 FPS.
FPS
How many frames per second to target. If you have a high end system, 60 fps looks very fluid and is preferred for fast action games like FPS / fighting games. A higher frame rate is directly tied to an increase in CPU requirements, eg 60 fps will require twice as much CPU power as 30 fps. However, 60 fps may not require twice the bitrate, since the improvement in fluidity from 30 fps to 60 fps means there is less time for the eye to notice a quality loss. If you find you have a great CPU but low upload, increasing FPS is one of the best ways to improve quality
Im busy working my way through all the documentation on this forum. The above I found under Support (Guides). Based on the abive I will go with 30fps to get the most quality out of my CPU, without impacting my upload capacity negatively.

Im going to do some more testing tonight, but its tricky to to broadcast and view the stream at the same time. I did this last night, and ended up with some serious echo coming through over and over and over... Until I figured out that I was streaming and re-streaming the sounds in the game, and it was coming through the stream... fail lol :)

I will connect a laptop through a LTE connection tonight to view the stream, thereby not impacting my broadcast setup/connection at all.

edit : Im gonna round up to 700 kbps as well and see how it goes ;)
 
#7
Kharay said:
To avoid said echo -- just turn the audio of the stream off? :S
yes I will do this, but I dont really have the internet bandwidth to test the broadcast and have a sample stream on the same connection. This is why I will put them on seperate connections.

Thanks for all the help, much appreciated.
 
#8
A very quick and easy way to check quality as you're tweaking OBS -- Broadcast Settings: File Output only. ;) And then when you're 100% satisfied, you can switch back to actually streaming.
 
#9
Kharay said:
A very quick and easy way to check quality as you're tweaking OBS -- Broadcast Settings: File Output only. ;) And then when you're 100% satisfied, you can switch back to actually streaming.
ah, this is an excellent suggestion! I will do this first, and then work on if that quality can be uploaded.

I have a quick question regarding Twitch, if you dont mind? I know its slightly off topic.

Lets say that I do go with 480p at 700kbps. I run a 1920 x 1200 screens (2 of them) but this means nothing in terms of the stream. Twitch will supply (to any viewer) a stream of 480p (not sure of the EXACT res, I think they will use 16:9 whereas my screens are 16:10)

What happens if the person watching doesnt have internet fast enough to watch? Will they have an option to select a lower quality? Or will they only have available what I stream ie. 480p
 
#10
Only Twitch.TV Partners have the option of different resolutions. Anyone that is not partnered will only show one resolution, the resolution being streamed at.
 
#13
Im back... :)

A question on CBR. When CBR is ticked, the quality option gets greyed out. Can you please confirm that once you have CBR ticked that quality setting (1-10) does absolutely nothing?
 
#14
Why else would it be greyed out? CBR and VBR are mutually exclusive. It is either one or the other. CBR will make the encoder try and maintain the specified bitrate, VBR will make the encoder try and maintain the specified quality level.
 
#15
Kharay said:
Why else would it be greyed out? CBR and VBR are mutually exclusive. It is either one or the other. CBR will make the encoder try and maintain the specified bitrate, VBR will make the encoder try and maintain the specified quality level.
Yes I thought so, I just wanted to make 100% certain. Thank you Kharay
 
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