Nvvidconv crop failed

Autonomous Machines Jetson & Embedded Systems Jetson TX2
#1

Hi

I am trying to crop image on TX2 using nvvidconv

I am using Jetpack version 28.2.1 and gstreamer version 1.8.3

My pipeline is working well using the nvvidconv element without setting properties

BUT when I am trying to set any of crop property (top,bottom,left,right) I get critical error from my pipeline

do you know what the reason for that error?

#3

Hi,
Please share the pipeline and the reported error.

#4

Be aware that, as opposed to videocrop, nvvidconv parameters are not the margins, but the X or Y coordinates.
For top and left these are the same as with videocrop, but you would set:
right = width - rightMargin
and
bottom = height - bottomMargin.

Example removing 100 columns on left and right and 100 rows on top and bottom from a 640x480 frame giving a 440x280 frame:

gst-launch-1.0 -v videotestsrc ! video/x-raw, format=YUY2, width=640, height=480, framerate=30/1 ! nvvidconv left=100 right=539 top=100 bottom=379 ! 'video/x-raw(memory:NVMM), width=440, height=280' ! nvvidconv ! xvimagesink
#6

The above information is important to know and at odds with current documentation.

gst-inspect-1.0 nvvidconv outputs:

  left                : Pixels to crop at left
                        flags: readable, writable
                        Integer. Range: 0 - 2147483647 Default: 0 
  right               : Pixels to crop at right
                        flags: readable, writable
                        Integer. Range: 0 - 2147483647 Default: 0 
  top                 : Pixels to crop at top
                        flags: readable, writable
                        Integer. Range: 0 - 2147483647 Default: 0 
  bottom              : Pixels to crop at bottom
                        flags: readable, writable
                        Integer. Range: 0 - 2147483647 Default: 0

However, setting those values to 0 crashes the pipeline.

#7

FYI the Accelerated GStreamer User Guide. shows an example of how to use nvvidconv for scaling:

gst-launch-1.0 videotestsrc ! \
 'video/x-raw, format=(string)I420, width=(int)1280, \
height=(int)720' ! nvvidconv ! \
 'video/x-raw(memory:NVMM), width=(int)640, height=(int)480, \
 format=(string)I420' ! omxh264enc ! \
 'video/x-h264, stream-format=(string)byte-stream' ! h264parse ! \
 qtmux ! filesink location=test.mp4 -e
#8

I’ve edited my post above for fixing an error. width would be right - left +1 and height would be bottom - top + 1.This may be required for keeping pixel-aspect-ratio tp 1/1.