The pliCount
property of the RTCRtpStreamStats
dictionary states the number of times the stream's receiving end sent a Picture Loss Indication (PLI) packet to the sender. A PLI packet indicates that some amount of encoded video data has been lost for one or more frames.
Syntax
var pliCount = RTCRtpStreamStats.pliCount;
Value
An integer value indicating the number of times a PLI packet was sent by the stream's receiver to the sender.
A PLI message is used by video decoders (running on the receiving end of the stream) to notify the encoder (the sender) that an undefined amount of coded video data, which may span frame boundaries, has been lost.
This may trigger the sender to send a full frame in order to allow the receiver to re-synchronize, since lost data may be an irrecoverable situation for decoding media. However, the primary purpose of this message is to allow the sender to consider techniques to mitigate network performance issues. This is often achieved by methods such as increasing the compression, lowering resolution, or finding other ways to reduce the bit rate of the stream.
Note: This value is only available on the receiver, and only for video media.
Specifications
Specification | Status | Comment |
---|---|---|
Identifiers for WebRTC's Statistics API The definition of 'RTCInboundRtpStreamStats: pliCount' in that specification. |
Candidate Recommendation | Initial definition. |
Identifiers for WebRTC's Statistics API The definition of 'RTCOutboundRtpStreamStats: pliCount' in that specification. |
Candidate Recommendation | Initial definition. |
Browser compatibility
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
pliCount | 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
See also
- RFC 4585: 6.3.1: Definition of "PLI messages" in the document Extended RTP Profile for Real-time Transport Control Protocol (RTCP)-Based Feedback (RTP/AVPF).