Horizontal lines in video output

[clemon]

using a UI-1241LE-C-HQ. Almost any time the camera sees movement, these horizontal lines are visible. They do not move.

everything looks fine in the ueyedemo, which leads me to believe its an issue with this plugin. Seen using simple pipeline: gst-launch-1.0 ueyesrc do-timestamp=true ! videoconvert ! ximagesink

Have any insight into what may be causing this problem? Willing to help out and contribute if I can.

[clemon]

Found out it has something to do with the new version of the sdk. Revert to 4.40 and it should work fine. Pretty stumped on finding out what causes this though.

[akmalhisyam36]

Hello,

I'm using the gst-plugin-ueye with UI388xLE-C on Ubuntu 17.10. And I'm encountering the same problem as @clemon having horizontal lines visible. @clemon what is the sdk are you talking about? Sorry, i'm quite new with advanced programming. @paulbarber is also invited to comment on this ^^ Thanks in advance !

[paulbarber]

Hi, I never saw this so may not be much help. The plugin just takes the image buffer, maybe reformats the pixels (eg into RGB), and puts in down the pipeline.
Issues like this are usually due to timing. Maybe the camera driver is part way through writing the buffer when the plugin accesses it, or the imagesink buffer is not in sync with the graphics adaptor of the PC. Normally you see tearing of the image when this happens not replacement of blocks like this.
How does frame rate effect the issue?

[akmalhisyam36]

Thank you @paulbarber for replying. I tried this pipeline gst-launch-1.0 -v ueyesrc ! decodebin ! videoconvert ! video/x-raw,format=\(string\)RGB ! videoconvert ! xvimagesink but the display remains to output the same horizontal lines. I haven't yet found a solution to change the frametrate using a pipeline. gst-inspect-1.0 shows that ueyesrc have a framerate range between [ 0/1, 2147483647/1 ] then I tried to add framerate=25/1 after ...format=\(string\)RGB, but it gave me an error when I launched the command line. Can you please enlighten me how to change framerate using a pipeline. Thanks in advance!

[paulbarber]

Type gst-inspect-1.0 ueyesrc for the properties of the element. Exposure time is one property you can change. If I can remember, the frame rate is set by 1/(exposure time) or "max frame rate", whichever is less.

[krisklau]

Hi @akmalhisyam36, was the issue resolved by changing the framerate?

And @paulbarber if I may; The library has not been updated in a while, but is it reasonable to assume that since Gstreamer 1.0 is pretty stable and the u-eye SDK mostly backwards compatible, that this library should continue to work? Is there a list of known bugs or missing features?

[paulbarber]

Hi, we developed the plugin with the features needed and froze the design so I cannot say whether it works with libraries. There are no lists, there maybe comments in the code. Gst-inspect will tell you what has been implemented.

[cuonggarlik]

We are currently having the same issue with those horizontal lines. It's on Jetson TX2 so the SDK version 4.40 is not available. Could anyone provide me any fix for this issue? Thanks a lot