RTCOutboundRtpStreamStats: qualityLimitationReason property

Limited availability

This feature is not Baseline because it does not work in some of the most widely-used browsers.

Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The qualityLimitationReason property of the RTCOutboundRtpStreamStats dictionary is a string indicating the reason why the media quality in the stream is currently being reduced by the codec during encoding, or none if no quality reduction is being performed.

This quality reduction may include changes such as reduced frame rate or resolution, or an increase in compression factor. Note that the user agent report the most limiting factor. If the most limiting factor cannot be determined the result will be reported using the priority order: "bandwidth", "cpu", "other".

The amount of time the encoded media has had its quality reduced in each of the potential ways that can be done can be found in qualityLimitationDurations.

Note: The property is undefined for audio streams.

Value

A string with one of the following values:

none

The quality is not limited.

cpu

The quality is primarily limited due to CPU load.

bandwidth

The quality is primarily limited due to congestion cues during bandwidth estimation, such as inter-arrival time and round-trip time.

other

The quality is primarily limited for a reason other than the above.

Specifications

Specification
Identifiers for WebRTC's Statistics API
# dom-rtcoutboundrtpstreamstats-qualitylimitationreason

Browser compatibility

desktop mobile
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
qualityLimitationReason in 'outbound-rtp' stats
Experimental
Chrome – Full support
Chrome 80 (Release date: 2020-02-04)
footnote Full support
Edge – Full support
Edge 80 (Release date: 2020-02-07)
footnote Full support
Firefox – No support
Firefox
footnote No support
Opera – Full support
Opera 67 (Release date: 2020-03-03)
footnote Full support
Safari – No support
Safari
footnote No support
Chrome Android – Full support
Chrome Android 80 (Release date: 2020-02-04)
footnote Full support
Firefox for Android – No support
Firefox for Android
footnote No support
Opera Android – Full support
Opera Android 57 (Release date: 2020-03-30)
footnote Full support
Safari on iOS – No support
Safari on iOS
footnote No support
Samsung Internet – Full support
Samsung Internet 13 (Release date: 2020-12-02)
footnote Full support
WebView Android – Full support
WebView Android 80 (Release date: 2020-02-04)
footnote Full support
WebView on iOS – No support
WebView on iOS
footnote No support

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support
No support
No support
Experimental. Expect behavior to change in the future.