Latency in QGC when Receiving H.265 Video Stream

[nechtobolshee]

We are experiencing a consistent 150+ms latency when receiving H.265 video streams in QGroundControl (QGC). The same stream, when tested outside of QGC (using tools like gst-launch), does not show this level of latency, which suggests that the delay is occurring within QGC's internal handling of the stream.

Expected Behavior

Latency less than 50ms when processing QGC images (including decoding).

Current Behavior

Latency over 150ms when receiving H.265 video stream (150+ms latency inside QGC -> decoding and processing)

Steps to Reproduce:

Please provide an unambiguous set of steps to reproduce the current behavior

1. Stream H.265 encoded video to QGC
2. Observe the latency between the actual event and the video display in QGC
3. Perform the same test using gst-launch or similar external tools to verify the stream performance outside of QGC (latency is much lower or non-existent).

System Information

• Operating System: Ubuntu 22.04
• QGC build: daily
• Video source: H.265 over UDP

Detailed Description

It is necessary to understand why this latency occurs. The low latency mode is enabled in the settings.

Could you please point me to the code area in QGC where I can see the final GStreamer pipeline used to receive the stream?

[nechtobolshee]

@HTRamsey I saw that you made a large update for GStreamer yesterday. Could you check this case?
Also, where can I see the final GStreamer pipeline used to obtain the stream? Thanks.