Webrtcbin: "do-nack" seems to have no effect
I admit, I might be wrong. Beforehand. To not be misunderstood.
- Java app based upon org.freedesktop.gstreamer:gst1-java-core:1.1.0, JDK 1.8
- Mac OS 10.14.5
- Java application just sends test-video, but fetches video from remote (no audio at all)
- Remote clients: Raspberry PI based on UV4L, browser app (Chrome, Firefox)
- Gstreamer 1.16.0 via brew
I was trying to harden the Java/Gstreamer implementation, since it has the problem, that it shows up artefacts which do not disappear, once there are packet losses downstream.
For that I was able to obtain the RTP statistics. My current solution is to issue a FIR request towards remote, once I see increasing packet losses inbound. But no more than one FIR per 5 seconds. These FIR requests are visible in the received video and counted in the remote statistics (not in a browser, but this might be a problem of the browser implementation) and basically this solution works for me.
I wanted to give the "do-nack" thing a try, which is disabled by default. I'm able to set and retrieve the value of do-nack, having done that on both streams now.
I was thinking, that a significant packet-loss on the inbound stream would force the Java/Gstreamer app to send NACKs, but I can't see them in the statistics of the remote side. And I could also not see any impact on the quality of the received video. Not sure if this expectation is true at all.
So my assumption is, that there is no effect of this setting at all.