Is it possible to convert from memory:CUDAMemory to memory:NVMM?

Application Development
1

When using decoders from the nvcodec plugin together with NVIDIA DeepStream it would be very good if it would be possible to keep memory on the GPU between the decoder and nvstreammux. Ideal would be if the decoder had support for memory:NVMM. That is not the case though, so the second best option would be if it was possible to convert from e.g. memory:CUDAMemory to memory:NVMM. Neither cudaupload not cudadownload seems to support that case. Converting like this:
… “video/x-raw(memory:CUDAMemory)” ! cudadownload ! “video/x-raw(memory:NVMM)” …
is accepted by cudadownload without any errors, but sending the buffers to nvstreammux results in the error “error: input buffer [stream_id=0] is not NVMM format; FATAL error”.

Is there a way to get this conversion to work?

2

Not sure, someone more skilled may correct my understanding.

I think that NVMM memory refers to DMA-able memory (contiguous memory with linear allocator) for iGPUs such as Drive or Jetson platforms, while CUDAMemory is rather related to dGPUs with cudadownload/cudaupload copies). With iGPU, for copying NVMM from/to system memory, see elements nvvidconv or DeepStream nvvideoconvert if available.

You may better tell your case for further advice from anyone more skilled.