Question / Help OBS ignores CBR bitrate

[RecordimusMaximus]

So, im recording/streaming with CBR encoding on x264 with a 17000bitrate
Yet, when doing it ill see in OBS status bar that the bitrate can reach even up to 20000 which is nearly 20% above the limit i set
Why is this happening? And most important, how to prevent it?

 

[Narcogen]

Are you recording or streaming? Because you probably shouldn't be streaming at that bitrate, and you shouldn't be recording with CBR.

https://obsproject.com/forum/resour...lity-recording-and-multiple-audio-tracks.221/

 

[Stream Doctor]

Definitely while streaming you'll see bitrate shoot over 6500 sometimes even with a 6000 CBR cap. Agree with Narco to probably roll VBR for a local recording or just go NVENC with a CQP setting.

 

[Narcogen]

CQP or CRF for recording, yes.

 

[RecordimusMaximus]

Are you recording or streaming? Because you probably shouldn't be streaming at that bitrate, and you shouldn't be recording with CBR.

https://obsproject.com/forum/resour...lity-recording-and-multiple-audio-tracks.221/

The problem is most annoying when I'm streamin (to YouTube that does not have bitrate limits like Twitch etc.). It's 1080p 60fps stream, sometimes 1440p 30fps but I'm limiting bitrate to not overshoot over my UL speed (20Mbps)

 

[Narcogen]

For *streaming* you absolutely should be using CBR. For recording, you should be using CRF or CQP. You don't need to (and probably shouldn't) use the same settings for both tasks.

 

[RecordimusMaximus]

For *streaming* you absolutely should be using CBR. For recording, you should be using CRF or CQP. You don't need to (and probably shouldn't) use the same settings for both tasks.

Ok then, so what about the CBR bitrate overshooting by nearly 20% of target bitrate? its normal? Nothing that can be done fo get rid of it?

 

[Stream Doctor]

Ok then, so what about the CBR bitrate overshooting by nearly 20% of target bitrate? its normal? Nothing that can be done fo get rid of it?

I'd say its pretty normal. I had mine capped at 6000kbps live streaming today and I was getting peaks of 6800+ . I'd say with a large target like 15000 the gap will widen even further.

 

[R1CH]

You should be aware that the bitrate shown at the bottom is the network bitrate, not the video bitrate. As video is produced at a non-constant rate (keyframes for example are much larger than other types of frames), some variance is expected.