No way to get/calculate/implement latency metric

[VasylKhmil]

Unfortunately there are no ways to get latency metrics for chime session.

In our application we are trying to build a low latency synchronised process that require to know latency parameter.

Unfortunately Chime SDK do not provide such parameter in metrics our of the box.

Every VideoFrame have property timestampNs, but this property differs per device and do not allow to calculate latency at any scenario.

Also I were trying to implement it myself by applying metadata into CVPixelBuffer. But AWS Chime is overriding this params and receiver do not get it.

So there are no ways to implement latency calculation. Maybe somebody know some scenarios how to achieve that?

[hokyungh]

We currently expose videoSendRttMs, would that be enough for your use case or is there specific thing you are expecting?

[VasylKhmil]

Hey. Unfortunately RTT is near 120-150 ms, while real latency is 400-600 ms. So I assume RTT is a value that tell how long will take to send data message, but not video frame latency. So unfortunately this is not helping.

[VasylKhmil]

I have counted real latency by putting two devices in front of third one with timer and making the screenshot on one of them. The difference on pictures is the exact latency, as one tile is local one directly from camera, and another - remote from another device.

[VasylKhmil]

I would love to help, for example to persist frame metadata, or implement latency calculation, or to implement audio filters. But all this is under Media SDK that's closed.

[dylonChime]

Thanks for your interest @VasylKhmil. I'll leave this as a feature request for 2 things.

1. Real Video Frame Latency Metrics.
2. An open source media layer so developers like yourself can contribute.