The firCount
property of the RTCRtpStreamStats
dictionary indicates the number of Full Intra Request (FIR) packets have been sent by the receiver to the sender. This is a measure of how often the stream falls behind and has to skip frames in order to catch up.
Syntax
var firCount = RTCRtpStreamStats.firCount;
Value
An integer value indicating how many FIR packets have been received by the sender during the current connection. This value is available only on receivers for video tracks.
The receiver sends a FIR packet to the sender any time it falls bahind or loses packets and cannot decode the incoming stream any longer because of the lost data. This tells the sender to send a full frame instead of a delta frame, so that the receiver can catch up.
The higher firCount
is, the more often frames were dropped, which may be an indication that the media's bit rate is too high for the available bandwidth, or that the receiving device is overburdened and is therefore unable to process the incoming data.
Specifications
Specification | Status | Comment |
---|---|---|
Identifiers for WebRTC's Statistics API The definition of 'RTCInboundRtpStreamStats: firCount' in that specification. |
Candidate Recommendation | Initial definition. |
Identifiers for WebRTC's Statistics API The definition of 'RTCOutboundRtpStreamStats: firCount' in that specification. |
Candidate Recommendation | Initial definition. |
Browser compatibility
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
firCount | Chrome No support No | Edge No support No | Firefox Full support 55 | IE No support No | Opera No support No | Safari ? | WebView Android No support No | Chrome Android No support No | Firefox Android Full support 55 | Opera Android No support No | Safari iOS ? | Samsung Internet Android No support No |
Legend
- Full support
- Full support
- No support
- No support
- Compatibility unknown
- Compatibility unknown