This feature is well established and works across many devices and browser versions. It’s been available across browsers since March 2022.
The sdpFmtpLine property of the RTCCodecStats dictionary is a string containing the format-specific parameters of the codec.
These are the values in the "a=fmtp" line in the codec's SDP (if present) after the payload type number (see section 5.8 of the IETF specification for JSEP).
A string containing the format-specific parameters of the codec.
The "a=fmtp" line in the codec's SDP line has the following format, where the payload type (see RTCCodecStats.payloadType) and parameters depend on the codec:
a=fmtp:<payload_type_number> param1=value1; ...; paramN=valueN
For example, the following line would indicate that the "opus" codec, which has a payloadType 99, has the format-specific parameters maxplaybackrate and stereo:
a=fmtp:99 maxplaybackrate=16000; stereo=1;
For this codec, the value in sdpFmtpLine would be maxplaybackrate=16000; stereo=1;.
| Desktop | Mobile | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chrome | Edge | Firefox | Opera | Safari | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | WebView Android | WebView on iOS | |
sdpFmtpLine |
83 | 83 | 98 | 69 | 14 | 83 | 98 | 59 | 14 | 13.0 | 83 | 14 |
codecs.sdpFmtpLine option in parameter passed to RTCRtpTransceiver.setCodecPreferences() and RTCRtpSender.setParameters().codecs.sdpFmtpLine in object returned by RTCRtpSender.getParameters() and RTCRtpReceiver.getParameters().
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https://developer.mozilla.org/en-US/docs/Web/API/RTCCodecStats/sdpFmtpLine