Access NVMM mapped nvarguscamerasrc frames from CUDA on Jetson Orin AGX

[TAX]

Hi Guys,

I have been spending the past days trying to access nvarguscamerasrc frames from gstreamer, but untill now with no luck. I am aware of the NV12 format (video/x-raw(memory:NVMM)) and I just need to access its y_channel.

I need to both read from and write to the y_channel.

I have shared a repo with my minimal gstreamer plugin alongside a build script that can be run by “make clean test”

GitHub - taxfromdk/jetson_cuda_sample

It executes a pipeline

gst-launch-1.0
nvarguscamerasrc sensor-id=1
! “video/x-raw(memory:NVMM),format=NV12,width=3840,height=2160,framerate=30/1”
! cudasample
! nvv4l2h265enc iframeinterval=90 maxperf-enable=true insert-sps-pps=true preset-level=1 insert-vui=true insert-aud=true bitrate=8000000
! h265parse config-interval=-1
! queue
! mpegtsmux
! tcpserversink host=“0.0.0.0” port=9002

And i test the pipeline from a networked PC using

ffplay -fflags nobuffer -flags low_delay -framedrop -strict experimental -probesize 32 -sync ext tcp://host_ip:9002

The plugin I have implemented is “cudasample”

Regardless of my attempts I always get an “an illegal memory access was encountered”.

I would appreciate some pointers, or ideally a pull request, on how to access the y data from a cuda kernel.

[DaneLLL]

Hi,
NVMM buffer is based on NvBufSurface APIs, so you can access the buffer through the APIs. There is demonstration in jetson_multimedia_api and please check 12 sample. And nvarguscamerasrc is open source. You can customize it to add the function.