Question / Help Quick question on bitrate vs encoding presets.

[UrzuS3V3N]

Hey folks,

So, i'm building a second dedicated streaming PC and I was wondering a little about the bit rate vs encoding presets.

At the moment i'm streaming at 1080p @ 30 or 720p @ 60 if its really fast paced with 3000 bit rate. While it looks good on stream, the FPS on my end is horrible on some games, hence the incoming 2 PC setup. Its also limiting the viewers with slower connections since the bit rate is so high.


Now when I get this streaming PC up and running, I was hoping that I could decrease the bit rate for people with slower internet connections to watch while still maintaining 1080 @ 30, 720 @ 60 or maybe even 1080 @ 60.

Can you guys suggest what profiles / bit rates would be best.

the 2nd PC will be:

i7 3770 using the Live Gamer HD.

I could opt for a 3770k and OC it with water cooling if it would enhance my options vs the price increase.

Any and all suggestions/information appreciated.

If you need any further info don't hesitate to ask.

Thanks,

S3V3N

 

[Jack0r]

You might be able to add a tweak or two or even use one preset "slower" than on a non-overclocked i7. But that will probably be it. In general the i7 should be a very good streaming PC. A bigger jump would probably be getting a 6-core i7 in the newest generation, but these are currently just too expensive and overkill, more meant for a gaming PC I would say.

I made some quality comparisons using the x264 encoder and its ssim tests. These test the similarity of the original picture to the encoded output. I noticed that the preset's cannot increase this "value" by a big margin, but the perceived quality result, so what you experience with your eyes, definitely improves through the different presets.
So its in the end a question of balance, the slow preset for example uses lets say 75% more cpu power but increases the quality just by 10% (probably less) compared to medium, the biggest steps are between very fast to faster and fast by the way. Going to medium/slow only increases the quality by a very low margin, but increases the cpu usage by a big one.

Edit: http://jack0r.com/high/preset_to_quality.html
The blue section is the cpu usage increase(green), the red section the quality increase(black).

 

[UrzuS3V3N]

Ahhh, that helps! TY! So basically I just stick it on fast, medium if I have the spare headroom, and then all I need to play with is the bit rate?

What bit rate would you recommend for non partner streams? I really dont want to sacrifice too much quality but do wish to expand who is able to watch without constant buffering?

 

[Sapiens]

720p30 at 2000-2500 Kbps is the general recommendation, though a higher resolution/frame rate can look acceptable at those bitrates if the source content is low motion.