Gstreamer : Frame Number at application

[Siddharth]

I am working on one custom application on imx8mm using GStreamer and facing the issue of latency in RTSP while running the live video(1920x1080: 20 fps:h264 ) on VLC of around 1.5 seconds.

I have one question regarding the issue :
a) Do we have any plugins or properties on GStreamer to find the frame number on the GStreamer application?
do-timestamp is not working properly (offset is -1: Gstbuffer member)

b) Any API to get the frame number at the application to find the comparison with the frame captured at a low level?
c) Is latency can be reduced?

Thanks
Regards
Siddharth Singh

[Siddharth]

BSP Version : 

Linux imx8mmevk 5.4.24-2.1.0+ge94682e3ac7d #1 SMP PREEMPT Mon Aug 23 13:41:17 UTC 2021 aarch64 aarch64 aarch64 GNU/Linux

[joanxie]

did you find the a/v sync issue? could you share the commands you use? if you want to get absolute timestamp, maybe you can refer to the link as below:

"https://stackoverflow.com/questions/6149983/h-264-rtsp-absolute-timestamp"

and I found in the encoder and decoder source code, structure GstVideoCodecFrame has pts for frame timestamp, you can export this to check, and as I known the latest bsp fixed many latency or A/V sync issue, maybe you can try the latest bsp to test again

[joanxie]

what bsp version do you test?