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WebRTC Metrics

A comprehensive overview of WebRTC statistics, derived indicators, and observable signals, to better understand call quality, connectivity, and user experience in rtcStats

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inbound-rtpinboundvideo

framesDropped/Received(%)

The percentage of frames that were dropped.

Description

Real number

MUST NOT exist for audio (this is video only).

Represents the percentage of frames that were dropped out of the frames that were received.

Interpreting Values

The table below can give a rough estimation as to what to expect based on the percentage of frames dropped and the resultant video quality: | Range | Description | |-------|-------------| | <1% | Good. Minimal visible impact | | 1-5% | Noticeable for motion-heavy content | | 5-10% | Clearly degraded video | | >10% | Significantly impaired |

Common Causes

  • CPU unable to decode fast enough
  • Renderer overloaded
  • Display deadline missed
  • System under memory pressure
  • Too many video streams being decoded simultaneously

User Experience Impact

  • Video appears to stutter or skip
  • Motion becomes jerky
  • If sustained, effective frame rate drops well below what the sender intended

Troubleshooting

  • Check totalDecodeTime/framesDecoded for slow decoding. If decode time per frame approaches the frame interval (e.g., >33ms for 30fps), CPU is the bottleneck
  • Reduce incoming video resolution or number of incoming streams
  • Close competing tabs and applications

See also

Notes

  • Frames can be dropped before or after being decoded and for various reasons