Explore the gstreamer pipeline with opencv

[DaneLLL]

Hi,

@LoveNvidia

Is it possible to remove the decoded frames from NVMM buffer when copied into cpu buffer? Is it possible to limit the queue of NVMM buffer and CPU buffer?

The hardware decoder decodes frames into NVMM buffers. OpenCV take CPU buffers, so the memory copy is required if you have to use OpenCV.

@LoveNvidia

What’s difference between videoconvert ! video/x-raw,format=BGR and videoconvert ?
when I put videoconvert instead of videoconvert ! video/x-raw,format=BGR , Than’s work correctly, why? in the only using videoconvert , the converation to BGR don’t occured or this is done by default in videoconvert ?

If caps is not specified in the pipeline, it does auto caps negotiation. By default the appsink requests for CPU buffers in BGR format so it still runs like

videoconvert ! video/x-raw,format=BGR ! appsink

@LoveNvidia

Is the pipeline above efficient for decoding? If not so, How I can solve the problem?

It is optimal solution to run OpenCV on Jetson platforms. Due to limitation of hardware converter, need to have software converter to convert RGBA/BGRx to BGR.