Setting exposure for Webcam doesn’t work with DeepStream 5.0

[Aswin]

Hi , 

I am building a G streamer pipeline for YOLO on Nvidia Jetson Nano.

This pipeline uses live feed captured through USB WEBCAM as input.

I need to operate the feed at a specific exposure setting.

I have changed the exposure settings as follows :

FROM :

*caps_v4l2src.set_property(‘caps’, Gst.Caps.from_string(“video/x-raw,
framerate=30/1”))
caps_vidconvsrc.set_property(‘caps’,
Gst.Caps.from_string(“video/x-raw(memory:NVMM)”))
*

TO :

*caps_v4l2src.set_property(‘caps’, Gst.Caps.from_string(“video/x-raw,
framerate=(fraction)30/1, auto-exposure=(int)1,
exposure-time=(double)166.66999999999999, width=(int)640, height=(int)480”))
caps_vidconvsrc.set_property(‘caps’,
Gst.Caps.from_string(“video/x-raw(memory:NVMM)”))*

I have verified this change in the pipeline in the following way :

*print(“Exposure Mode :”,
caps.get_property(‘caps’).get_structure(0).get_value(‘auto-exposure’))
print(“Exposure Time :”,
caps.get_property(‘caps’).get_structure(0).get_value(‘exposure-time’))
print(“Frame Width :”,
caps.get_property(‘caps’).get_structure(0).get_value(‘width’))
print(“Frame Height :”,
caps.get_property(‘caps’).get_structure(0).get_value(‘height’))
print(“Frame Rate :”,
caps.get_property(‘caps’).get_structure(0).get_fraction(‘framerate’))*

This results as follows :

*Exposure Mode : 1
Exposure Time : 166.67
Frame Width : 640
Frame Height : 480
Frame Rate : (True, value_numerator=30, value_denominator=1)*


The pipeline produces 29 FPS with lights turned on.

When the lights are turned off or camera is covered in such a way to block
lights, FPS reduces to 15.

/This indicates that EXPOSURE change/setting has not happened in the
gstreamer./

/But i am able to successfully set the exposure setting using opencv in
python on the same camera./

Any possible guide on how to control the EXPOSURE, WIDTH, HEIGHT in the
pipeline ?



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