Libargus c++ api returns yuv frames with null uv-plane

[mstunda]

I have an IMX477 camera connected to Jetson Orin Nano. The camera provides a normal colored video stream using a gst-launch script.

However, when I try to run the c++ examples provided in jetson-multimedia-api-reference, I get the yuv420p (YCbCr_420_888) frame with an ok Y plane, but the UV plane is all zeros (sized correctly). When I convert the .yuv image to .jpeg (via ffmpeg), the image is well-lit and detailed, but green. I tried setting a lower resolution and turning the IspStage off, but it changed nothing.

So far I tried the approaches in examples argus/samples/rawBayerOutput and argus/samples/yuvOneShot. For the first one i changed the pixelformat to yuv. But the RAW16 provided originally also didn’t seem to have any color. I changed almost nothing in the yuvOneShot example, just disabled the preview thread (running headless).

Any ideas on what i’m doing wrong?

[JerryChang]

hello mstunda,

@mstunda

I have an IMX477 camera connected to Jetson Orin Nano.

just double check, is it Raspberry PI HQ camera, IMX477?

besides,
may I also know what’s your real use-case, would you like to receive the frames with YUV420p?

[mstunda]

Hi,
Yes, it’s the reaspberry camera, Revision D.
I have a C++ application that processes, encodes, and forwards frames to various endpoints. I want to obtain frames in yuv420p, yes.

[JerryChang]

hello mstunda,

Bayer Raw camera sensors it’s by default processed by internal ISP as YUV420SP, (or, NV12).
for instance, here’s simple gst pipeline for launching camera to preview.
$ gst-launch-1.0 nvarguscamerasrc ! 'video/x-raw(memory:NVMM),framerate=30/1,format=NV12' ! nvvidconv ! xvimagesink

hence,
you may try adding video converter to covert from YUV420SP to YUV420P.
for example,
$ gst-launch-1.0 nvarguscamerasrc ! 'video/x-raw(memory:NVMM),framerate=30/1,format=NV12' ! nvvidconv ! 'video/x-raw, format=(string)I420, width=640, height=480' ! queue ! xvimagesink -e