CBR vs CQP for "Streaming", which is better? (Why not CQP?)
Hello Everyone,
I've been trying to find a technical answer to why it is often not advised to use CQP for streaming?
In theory if there are no issues it would result in a better and consistent quality right?
Thanks for any and all help!
22 Replies
A)obs is hard-coded to not use cqp. You can set it but it'll silently use CBR
B)stream services expect a somewhat consistent data rate
C)cqp will usually be way more data rate than what a stream service will ingest
A) You can use the "ignore streaming service setting recommendations" feature to resolve it hard coding back to CBR iirc?
B) True per their recommendations. But what if the stream is on Youtube where they have less limitations?
C) A friend of mine has a recent livestream using CQP @ 4k 60FPS (https://www.youtube.com/watch?v=q9srUT2vSlQ&t=10502s) and while he did get OBS messages like "you're not streaming enough bitrate, you should stream more than 3.5k" the stream as seen in the VOD looks good!
But this is all void if "ignore streaming service setting recommendations" does not remove the hard coded CBR
Just use CBR when streaming. Less problems
I do use CBR when streaming no worries!
I am just looking for a legitimate and technical answer as to why not CQP?
and now looking to confirm if "ignore streaming service setting recommendations" allows CQP without it hardcoding back to CBR?
Because there’s no practical benefit to having a variable bitrate when you’re already constrained to a sub optimal bitrate per twitch’s limit
In those scenarios CQP wouldn’t really have enough bitrate headroom to improve quality
And would lead to massive drops and spikes in bitrate, which is harder to ingest
Hey Alex! I am more so referring to Youtube where the bitrate has more headroom, apologies.
Obs is hard coded to use cbr for streams
Regardless of the "ignore stream service" box
Yes but per this forum https://obsproject.com/forum/threads/i-set-stream-encoder-to-use-cqp-but-it-seems-to-still-be-streaming-with-cbr.174294/ "ignore streaming service setting recommendations" allows CQP without it hardcoding back to CBR?
Because obs is hard coded to use cbr
Trust me
Ahh okay. Thats what I needed to know.
Bet if ya pulled up the obs log from the session where they "used cqp" it'll still say cbr as the rate control 😉
Thanks for the info! I really do appreciate it 🙏
Any time you have a bitrate ceiling cqp is a bad application because it assumes you basically don’t
The quality value does limit bits per frame
But again, you’d have to really know ffmpeg well to know X value = Y bitrate limit
That was my assumption aswell, but since a friend has been using it to success I quiestioned what I've researched and wanted to get a more technical answer. But if OBS hard codes it then everything is void anyhow
Thank you all for the help!
It'll silently use the last bitrate they set when using cbr
So if they are noticing "better quality" it's purely placebo 😉
Ahh and since the default is 2500 CBR that would explain the message he receiving being "you're not streaming enough bitrate, you should stream more than 3.5k"
The quality I assume is likely heavily contributed to it being "low action" and using AV1 on Youtubes VP9
I would have never thought that 2500 would be able to do this:
https://www.youtube.com/live/r4TjPy3WfwY?si=gijXWO7UA5W6R3dA&t=20087
even with AV1
4k 60 FPS at 2500 bitrate seems REALLY LOW to the point that I wouldn't even think it would work.
I only watch the recorded vods though
So:
- Change my setting to CBR
- Crank the bitrate to 40000?
- Change preset to p1?
If that link above was done at 2500kbps, yea, I'd say av1 is pretty impressive
And if you have the upload to support 40,000 full send that shit ha
that's what the settings were according to the logs.
I had it set to CQP 20 though in the OBS UI.
GG @StriderStone, you just advanced to level 4 !
that just can't be right...0 dropped frames or anything