Question / Help Max Bitrate and other questions

[KryspeH]

Hello,
I am new to this forum so I apologize if I do anything wrong. Now that I got that out of the way, my first question is what is the maximum bitrate that OBS currently allows? Also, I am having a hard time understanding what cbr padding and buffer size are. Another question is if cbr is unchecked, does it use vbr encoding and use the value for max bitrate as the average bitrate or something? Also, what is CFR in advanced settings? My last question really isn't OBS specific, but I thought I'd ask, so how exactly does the keyframe interval affect the quality of the video. Sorry for the ridiculous amount of questions. Any help would be appreciated. Thanks in advance.

 

[H4ndy]

I try to answer your question as I understand them.
If you have specific question, check the chat or look them up in a Wiki.

Max Bitrate: There is no artificial limit in OBS. I can do 100000 kbps (100 mbps) recording without issues. On the other side Twitch for example only allows about 3500 kbps streams for non-partners.

CBR (Constand Bitrate) padding: I'll quote Wikipedia for that: Most coding schemes such as Huffman coding or run-length encoding produce variable-length codes, making perfect CBR difficult to achieve. This is partly solved by varying the quantization (quality), and fully solved by the use of padding. (However, CBR is implied in a simple scheme like reducing all 16-bit audio samples to 8 bits.)

Buffer size: If you don't know what that is or for what you need it for, just leave it at the default values.

CFR: Constant Frame Rate. Locks the recording/stream encoding to the defined frame rate even of the game e.g. drops below it (shuttering) which is then compensated with duplicated frames. Usually required for compatibility reasons on the retrieving end of your stream.

Key frame: Tells the encoder at what frame interval he should save a full reference picture again. Simply speaking, modern encoders, like h.264 used by OBS, only save the changes from one frame to the next. This process is restarted every key frame.

And yes, if you uncheck CBR it will use VBR, which is recommended for local recordings. Check this info: https://obsproject.com/forum/resources/how-to-make-high-quality-local-recordings.16/