User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:51.0) Gecko/20100101 Firefox/51.0 Build ID: 20161201172143 Steps to reproduce: 1） I used webrtc of firefox version 54 to join video meeting 2) and I setted max-mbps (value is 1920*1080 15fps) in remote SDP fmtp attribute as I want to control my upload framerate Actual results: I found firefox webrtc can't controlled the framerate using max-mbps as expected,it sent 30fps large than 15fps.but it worked on firefox 52 Expected results: we expected max-mbps could also works on firefox version 54.If max-mbps could not work on version 54,I also find the max-fps parameter does not work.could you suggest anther way instead?

Can you tell if this is a regression?

Yes,I tested on FF 52 and the attribute max-mbps worked. I read the code of FF 54,and it wrote below information in function ConfigureSendMediaCodec of videoCondiut.cpp " if (codecConfig->mName == "H264") { if (codecConfig->mEncodingConstraints.maxMbps > 0) { // Not supported yet! CSFLogError(logTag, "%s H.264 max_mbps not supported yet", __FUNCTION__); } } " Could you help to tell how to controlled framerate in FF 54? Thanks

we also can not control framerate from firefox 53 . we use the max-fr/max-fs to control framerate/resolution before. https://bugzilla.mozilla.org/show_bug.cgi?id=1393687

Dan -- Is this a dup of the bug you've been working on?

Yes, same problem.

I'm going to reopen this for further investigation, it's not clear to me that the fixes over on Bug 1393687 worked for max-mbps.

If I set max-mbps to a small enough value that it attempts to reduce the framerate, I see a warning in the console from the H.264 codec from [1]: [OpenH264] this = 0x0x7fa71207da60, Warning:Actual input framerate 29.000000 is different from framerate in setting 22.000000, suggest to use other rate control modes That would imply that the requested framerate is in fact making it to the codec, but is not having the desired effect. [1] https://github.com/cisco/openh264/blob/master/codec/encoder/plus/src/welsEncoderExt.cpp#L646

How is issue going on? Dan