gstreamer-1.0 camera preview flickering

Robotics & Edge Computing Jetson & Embedded Systems Jetson TX1
1

i am using nvidia Jetson-TX1 board with gstreamer-1.0 v1.2.4.

Below is pipeline

//Camera preview

gst-launch-1.0 v4l2src device=/dev/video0 ! 'video/x-raw, width=1920, height=1080, format=UYVY, framerate=60/1' \ 
! nvvidconv ! 'video/x-raw(memory:NVMM), width=1920, height=1080, format=I420, framerate=60/1' \ 
! nvoverlaysink sync=false

// camera preview+textoverlay

gst-launch-1.0 v4l2src device=/dev/video0 \ 
! textoverlay text="Recording..." halignment=0 valignment=1 \ 
! 'video/x-raw, width=1920, height=1080, format=UYVY, framerate=60/1' \ 
! nvvidconv ! 'video/x-raw(memory:NVMM), width=1920, height=1080, format=I420, framerate=60/1' \ 
! nvoverlaysink sync=false

I am getting Flickering on camera preview with or without textoverlay. But in preview without textoverlay its not too noticeable. But when i on add textoverlay, flicking highlighted due to textoverlay.

This flickering happens with also with videotestsrc

gst-launch-1.0 videotestsrc \ 
! textoverlay text="Recording..." halignment=0 valignment=1 \ 
! 'video/x-raw, width=1920, height=1080, format=UYVY, framerate=60/1' \ 
! nvvidconv ! 'video/x-raw(memory:NVMM), width=1920, height=1080, format=I420, framerate=60/1' \ 
! nvoverlaysink sync=false

I have also tried to replace nvvidconv with videoconvert and nvoverlaysink with autovideosink but still flickers.

but when i remove UYVY format from above pipeline no flickers

gst-launch-1.0 videotestsrc \ 
! textoverlay text="Recording..." halignment=0 valignment=1 \ 
! videoconvert ! 'video/x-raw, width=1920, height=1080, format=I420, framerate=60/1' \ 
! nvoverlaysink sync=false

for my camera v4l2 i have to use UYVY to I420 conversion in order to view video so any other workaround?

2

Hi

I am seeing a similar problem with textoverlay on GStreamer 1.2.4. More precisely there are horizontal lines inside the text, when the video in the background is running and the image is changing.

Now i have compiled a newer version of GStreamer (1.8.0) and it looks like the problem as far as I can see it is gone. I have tested this with the videotestsrc, since the combination of v4l2src and Nvidia-elements (like nvvidconv, nvoverlaysink,…) does not work in the newer GStreamer version.

Hopefully Nvidia will support newer versions of GStreamer with the new L4T release that is coming up…