nvenc: no compatible devices found when compatible devices present

[mjlbach]

Xpra 4.0-r24434 fails to find available devices for nvenc that are detected under 3.0.2.

[mjlbach]

:4.log

[mjlbach]

loader.py output

[mjlbach]

nv_util.py.log

[mjlbach]

video_helper.py log

[Antoine Martin]

Very likely to have been caused by #2416.

[Antoine Martin]

Summary from the logs:

• the nvenc codec is installed and loads OK: nvenc/encoder.cpython-36m-x86_64-linux-gnu.so
• we find libcuda and libnvidia-encode:

  NVENC encoder API version 8.1
  init_nvencode_library() will try to load libcuda.so
  init_nvencode_library() <bound method LibraryLoader.LoadLibrary of <ctypes.LibraryLoader object at 0x7f19dc3d0c18>>(libcuda.so)=<CDLL 'libcuda.so', handle 7f198c2620b0 at 0x7f199274cdd8>
  init_nvencode_library() libcuda.cuCtxGetCurrent=<_FuncPtr object at 0x7f195328ea70>
  init_nvencode_library() will try to load libnvidia-encode.so.1
  init_nvencode_library() <bound method LibraryLoader.LoadLibrary of <ctypes.LibraryLoader object at 0x7f19dc3d0c18>>(libnvidia-encode.so.1)=<CDLL 'libnvidia-encode.so.1', handle 7f198c2a0f90 at 0x7f19900cff98>
  init_nvencode_library() NvEncodeAPICreateInstance=<_FuncPtr object at 0x7f195328eb38>
  

But no devices:

CUDA initialization (this may take a few seconds)
nvenc: no compatible devices found
NVidia driver version 430.50

Fixes:

• r24521 allow the 'load-balancing' config option to be loaded from the cuda.conf file(s)
• r24522 actual fix: missing variable and missing initialization flag

With these changes, my card does show up as it should:

$ python3 ./xpra/codecs/cuda_common/cuda_context.py 
CUDA initialization (this may take a few seconds)
CUDA 10.0.0 / PyCUDA 2019.1.2, found 1 device:
  + GeForce GTX 1070 @ 0000:01:00.0 (memory: 85% free, compute: 6.1)
pycuda_info
* version                         : 2019.1.2
  - text                          : 2019.1.2
cuda_info
* driver
  - driver_version                : 10020
  - version                       : 10.0.0
preferences:
* disabled-devices                : none
* enabled-devices                 : all
* load-balancing                  : memory
device automatically selected:
 GeForce GTX 1070 @ 0000:01:00.0

@mjlbach: there are updated beta builds with these fixes, please close if those work for you.

[mjlbach]

Resolved! Tested on Fedora 31 and Ubuntu 18.04