Bitrate in Admission Webhooks

[irlkitcom]

Add the bitrate from the client in the admission webhooks to have the option to deny incoming streams that are over a certain amount of bitrate.

[naanlizard]

This would be useful for us as well

[getroot]

AdmissionWebhooks operate before the client sends stream data. Therefore, OME cannot calculate the bitrates at that time.
Please refer to the Alert function below, which was created for that purpose.
https://airensoft.gitbook.io/ovenmediaengine/alert

[irlkitcom]

This is perfect, I didn't see it in the documentation at first.

[bchah]

A question on this - in the scenario where we need to block high bitrates - will the Alert function notify the control server before OME starts processing the incoming stream data? Or does this happen concurrently? The scenario I am wondering about is if somebody tried to "flood" the server with a 250Mbps stream, will we be able to fully block the transmission before it begins?

[getroot]

Because the bitrates are the number of bits transmitted per second, it is impossible for OME to know before they are received.

If it is essential, it is recommended to limit the maximum bandwidth per TCP/UDP session using external software such as Linux's tc.

[naanlizard]

Doesn't ome get a biterate value from the rtmp data? I'm wondering how we get the value in the API so exact matching the setting in the encoder.

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On Wed, Apr 3, 2024 at 10:15 Jeheon Han ***@***.***> wrote: Because the bitrates are the number of bits transmitted per second, it is impossible for OME to know before they are received. If it is essential, it is recommended to limit the maximum bandwidth per TCP/UDP session using external software such as Linux's tc. — Reply to this email directly, view it on GitHub <#1579 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABV4BWOLBZ6XSBENHG2AYHDY3QFJPAVCNFSM6AAAAABFULHFH2VHI2DSMVQWIX3LMV43SRDJONRXK43TNFXW4Q3PNVWWK3TUHM4DSOJXG43TO> . You are receiving this because you commented.Message ID: ***@***.*** com>

[bchah]

I think RTMP lets you 'declare' a bitrate as part of opening the stream, but that doesn't necessarily reflect the real-world bitrate reaching the server.

[getroot]

Yes, the bitrates value that OBS sends is just numeric meta information.
All encoders strive to achieve compression close to the set bitrates, but in fact it is a very technically difficult problem. You can achieve the target bitrates almost exactly by using two-pass encoding, but it will be difficult to do it live rather than in a file.
This is especially true because VBR does not have the goal of compressing to the set bitrates.

[naanlizard]

True, it certainly doesn't reflect e.g. VBR variations in bitrate, which is my biggest gripe. But it's usually pretty good for good faith users, who are all probably using obs anyway which seems to do well with it

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On Wed, Apr 3, 2024 at 10:20 bchah ***@***.***> wrote: I think RTMP lets you 'declare' a bitrate as part of opening the stream, but that doesn't necessarily reflect the real-world bitrate reaching the server. — Reply to this email directly, view it on GitHub <#1579 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABV4BWI4RIHXZOY6NUP73DDY3QF2XAVCNFSM6AAAAABFULHFH2VHI2DSMVQWIX3LMV43SRDJONRXK43TNFXW4Q3PNVWWK3TUHM4DSOJXHA2DI> . You are receiving this because you commented.Message ID: ***@***.*** com>

[naanlizard]

Yes, obviously VBR etc are special cases. In my experience, OBS' x264 CPU encoder is almost always extremely accurate with its encoding bitrate usage

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On Wed, Apr 3, 2024 at 10:39 Jeheon Han ***@***.***> wrote: Yes, the bitrates value that OBS sends is just numeric meta information. All encoders strive to achieve compression close to the set bitrates, but in fact it is a very technically difficult problem. You can achieve the target bitrates almost exactly by using two-pass encoding, but it will be difficult to do it live rather than in a file. This is especially true because VBR does not have the goal of compressing to the set bitrates. — Reply to this email directly, view it on GitHub <#1579 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABV4BWIQUI2VNRQFVASCBOTY3QIC3AVCNFSM6AAAAABFULHFH2VHI2DSMVQWIX3LMV43SRDJONRXK43TNFXW4Q3PNVWWK3TUHM4DSOJYGEYDA> . You are receiving this because you commented.Message ID: ***@***.*** com>