Question / Help Advice about OBS settings

Hi,
Q1: Some people said me, OBS is better than XSplit about CPU usage, it's correct? I actually use Dxtory + XSplit for streaming StarCraft II with low/-mid graphics
If it is, I would like to switch my live broadcast to OBS. :)

Here my OBS settings (I applied my XSplit settings) :

• - Quality : 6 (OBS estimator -> 7 or 8)
  - Max Bitrate (kb/s): 650 (estimator -> 723)
  - Buffer Size (kbit): 650 (estimator OBS -> 433)
  - Base Resolution: 1920 x 1080
  - Resolution Downscale: 1.50 (1280 x 720) (estimator -> 480p (720x480))
  - FPS: 30 (estimator -> 25)

About my computer :

• - AMD Phenom II X4 955 (3.20GHz)
  - HD 6800 series
  - 8Go

About my Internet connection :

• - 27 to 30 Mb/s Down
  - 0.85 to 1 Mb/s Up

Q2: Do you think I correctly configured OBS for my settings or I have to follow the "OBS Estimator"?
In my opinion, yes for the Max Bitrate & Buffer Size, since I saw your estimation :D, but what about the resolution and the fps?

Q3 : Moreover, can I use Dxtory with OBS or it's better to use the Game Capture of OBS directly?

Thanks for your help.
nAm

Q1: Is it better than Xsplit for CPU usage? Not necessarily, no.
Q2: Regarding the resolution -- The higher resolution will obviously mean a lower quality, given the somewhat limited bandwidth. If you can accept it, I think I would personally consider the suggestion of the estimator and go with 480p instead. Sure, it is a lower resolution but this also means it is a severely reduced number of pixels, meaning more bandwidth per pixel. Just try both options, 720p and 480p and see what you think looks better.
Q3: I would just use Game Capture directly. It's the option with the least number of variables and most likely the best performance in your situation.

Thanks for your answer @Kharay !

Ok about the CPU usage, if OBS is the same as XSplit, I will use OBS, since with it I don't have to use Dxtory.
Maybe I will win "some usage" without Dxtory ^^

Regarding the resolution, as you said I have a limited bandwidth. I will try to stream on 480p and configure OBS like the estimator suggest and I will see the result.

If others people have some advice, don't hesitate ;)

Thanks for your help.

I'd have to disagree... I've found OBS to have a significantly lower CPU footprint than XSplit most times, even without factoring in the additional overhead for DXtory. Which is unnecessary, with OBS; the game/window capture works much better than XS in that regard.

I'd also recommend running a 6MB test at http://testmy.net/upload to get a more accurate ballpark figure about your available constant throughput; would not set a buffer rate lower than the bitrate either (can lead to choppiness). Higher can help with some poor line quality situations, but that tends to be very trial-and-error.

Agreed with using Game Capture (or Window Capture with Aero enabled)... no need for dxtory, with OBS.

@FerretBomb, thanks for your reply.

Ok for the Game Capture, you are agreed :)
I will stop using Dxtory.

So I tested my upload connection with your link (6MB test), result my speed ~900 Kbps (2 times).
You said the values of estimator are not correct for the Max Bitrate & Buffer Size ?
What do you suggest for my case ?

Thanks.

If you are playing offline (no multiplayer) you can probably get away with 800kbps bitrate and buffer. If you are having small/intermittent frame drops, try bumping your buffer to 1600 to help smooth out any momentary connection issues a little. You can creep it upward until you start getting dropped frames, then back it down a bit... I'd still probably slap it at 800 and leave it there, as network throughput does fluctuate on a day-by-day basis (or hourly, or less). Would need to re-test a few times a day over a few days to get a good picture of how much it fluctuates in general/at what time of day/etc.

If you're playing online vs? You'll need to leave more; set OBS to a 600-700kbps bitrate. May have to back it down even further if you get an unacceptable amount of lag or start dropping frames again. Both game network communications and livestreaming both use constant upload throughput. Making them both behave together in the same bandwidth 'budget' is a good bit of trial and error. I'd also strongly advise using CBR (rendering the Quality setting moot) to more closely stay within your set bitrate limit... VBR can spike significantly higher during periods of high onscreen activity.

Also, make SURE your audio codec is set to AAC. Audio takes up some of the bandwidth budget as well, and AAC is excellent at providing good sound reproduction at low bitrates... I'd encourage you to test-stream at AAC-96, all the way down to AAC-64 or even 48. Every kilobit you can 'steal' from the audio stream will help to improve your video quality, when dealing with a low-upstream connection like that. :)

Thanks again for your advice @FerretBomb.

I'm playing online, specifically StarCracft 2.

http://www.twitch.tv/ymaneiram/b/427654804
On this vidéo I configure OBS with the values of estimator.
Quality : 6
Max Bitrate: 723
Buffer Size: 433
Resolution Downscale : 2.50 (768x432)
FPS : 30
Codec : AAC-96

With your advice :
http://www.twitch.tv/ymaneiram/b/427690450
Quality : 6
Max Bitrate: 650kbps
Buffer Size: 650kbps
Resolution Downscale : 2 (960x540)
FPS : 30
Codec : AAC-64

Maybe I can change the downscale to 1.75 (1096x616).
I'll try later.

Thanks for your help :)

I'd still recommend no higher than 480p with that bitrate... 360p would likely provide smoother performance and a better-quality output. Entirely up to you, just be sure to test it and review the VOD to make sure the quality is acceptable. You can also drop to 25fps to help image clarity as well by freeing up some more bitrate.

Ok so I will try with those settings :

Quality : 6
Max Bitrate: 650kbps
Buffer Size: 650kbps
Resolution Downscale : 2.50 (768x432) <- I think, I'm on 480p with this resolution or maybe 2.75?..
FPS : 25
Codec : AAC-64

I'll try tonight.
Thanks.