RTCCodecStats: sdpFmtpLine property

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since January 2020.

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).

Values

A string containing the format-specific parameters of the codec.

Description

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;.

Specifications

Specification
Identifiers for WebRTC's Statistics API
# dom-rtccodecstats-sdpfmtpline

Browser compatibility

BCD tables only load in the browser

See also