How to add buffer for RTSP server? - gstreamer

Question

I’m trying to create the following pipeline:
On Jetson:
1.1) camera -> … - > udpsink
1.2) udpsrc -> rtspserver
On Host PC
2.1) rtspsrc -> jitterbuffer -> detection -> tracker -> analytics
The main question is
My Jetson connected to Host PC over local WiFi network. I’ve choosen mesh WiFi Tenda Nova MW3. When Jetson reconnect from one WiFi access point to another, I loose some frames (from 0.5 to 10 seconds of stream). I understand that we cann’t get ideal seamless WiFi network, and system will "loose some frames" during reconnection.
I've try to setup buffer on udpsrc and udpsink, I've try to setup do-retransmission on rtspsrc, but it didn't work, or may be I did it wrong.
How to setup buffer in RTSP server to keep frames on Jetson client when it reconnects to another WiFi point and continue send frames from last point to Host PC?
Should I setup buffer on udpsink or udpsrc or rtspserver?
How to config rtpsrc to send frames from “losted time”?

Answer 1

I loose some frames (from 0.5 to 10 seconds of stream)
Maybe because decoder in Host pipeline misses the I frame, and should wait for the next I frame, 0.5~10s depends on the first frame position in the GOP(The GOP can be changed via encoder property).
You can use a rtmp server instead of rtsp, srs is a good choose, and open the gop cache. the pipeine would like to be camera -> encoder -> flvmux -> rtmpsink
vhost __defaultVhost__ {
gop_cache on;
}
The latency will increase while enable the gop cache, so the GOP for encoder should not be that large, may be 2s is good.
the pipeline on host pc may receive video data that had processed before reconnecting wifi, also the latency is bigger compare with gop disabled. If either counts, you should drop the outdated frame after decoding.