cuvidGetDecoderCaps not work with primary context

Asked Oct 22 '22 at 11:58

Active Oct 22 '22 at 11:58

Viewed 43 times

I use cuvidGetDecoderCaps to check whether my gpu suuport hevc decoding. I noticed that the calling thread needs to be associated with a valid context. I use cudaSetDevice to create a primary context, then call cuvidGetDecoderCaps, but still get error 101(cudaErrorInvalidDevice), do I have to call cuCtxCreate to explicitly create the context. code here:

CheckCudaErrors(cudaSetDevice(0));
CUcontext cuda_context = nullptr;
CheckCudaErrors(cuCtxGetCurrent(&cuda_context));
if (cuda_context == nullptr) {
  LOG(ERROR) << "cuda context is nullptr";
  return -1;
} else {
  LOG(INFO) << "cuda context is not nullptr";
}
CUVIDDECODECAPS decode_caps = {};
decode_caps.eCodecType = cudaVideoCodec_HEVC;
decode_caps.eChromaFormat = cudaVideoChromaFormat_420;
decode_caps.nBitDepthMinus8 = 0;
CheckCudaErrors(cuvidGetDecoderCaps(&decode_caps));

get output:

cuda context is not nullptr
Check failed: err == CUDA_SUCCESS (101 vs. 0) Cuda driver api error = 101(cudaErrorInvalidDevice)

Does anyone know why？

asked Oct 22 '22 at 11:58

375

1

cudaGetDevice doesn’t create a context – talonmies Oct 22 '22 at 14:52
Dose it create a primary context by calling `cudaSetDevice()`? After the calling, can indeed get a context. – 375 Oct 22 '22 at 15:03
No. Select the device and call cudaFree(0). Then you will have a context – talonmies Oct 22 '22 at 15:47

cuvidGetDecoderCaps not work with primary context

0 Answers0