How to EXIT GStreamer?

Autonomous Machines Jetson & Embedded Systems Jetson TX2
1

I’m trying to capture a sample image from my IMX274, using:

gst-launch-1.0 -e nvcamerasrc ! "video/x-raw(memory:NVMM), width=1920, height=1080, format=I420" ! nvjpegenc ! multifilesink location=snapshot.jpg

Can someone tell me how to exit gst-launch-1.0? Is my only option Ctrl-C? or is there some other, interactive commands? Right now, the app launches, prints some diagnostic information, then sits there, seemingly waiting for something, before I exit by pressing Ctrl-C.

2

Hi roach374, gst-launch subscribes to SIGINT signal that Ctrl+C sends, so it shutdowns gracefully when you do that - Ctrl+C is how to exit gst-launch.

If you want to see more console output from gst-launch, try launching it with the --verbose flag.

3

Thanks! I mostly just want to be sure I’m not missing out on some sort of interactive command palette. Starting up gst-launch, it basically runs the above pipeline, then sits there until SIGINT. I just wasn’t expecting it.

4

gst-launch doesn’t have an interactive mode, it simply runs the pipeline that you pass it in the command line arguments.

Apparently there is a gst-play application with keyboard interactivity, however I am unfamiliar with it.

5

You may also try option num-buffers with nvcamerasrc plugin. It specifies how many frames are to be acquired before it stops.

gst-inspect-1.0 nvcamerasrc

Usually the first 30 frames are dark before auto-everything gets up, so you may try to get enough frames and check last ones.

6

Interesting. What do you mean by “gets up”? Is this every time you start up GStreamer, or just during the power-up cycle of the physical camera?

7

I have no TX2 for testing and give accurate info, but I think each time you run nvcamerasrc gstreamer plugin, it activates nvcamera-deamon that configures the camera (not sure, but may involve exposure, gains, white balance, more…) and ISP.
From what I remember it was taking about 1s at 30 fps, but I cannot say much more for now.

8

I just ran into the problem with a fresh SD card image with the camera driver on it from the camera manufacturer. I eventually had to unplug the Jetson Nano. Later, I had VNC installed, and I ran the command. The video was full screen in the monitor connected to the jetson nano, but it was invisible through VNC. I was able to click on the terminal window and drag it around though VNC, while all I could see on the monitor connected to the jetson nano was the full screen video. Ctrl-C worked when the terminal window was listening for keyboard input. The first time, I must have clicked on something else, so the terminal window was no-longer listening to keyboard input, and ctrl-c wouldn’t work work then.

1 Like