... and put them into new nvcodec plugin.
* nvcodec plugin
Now each nvenc and nvdec element is moved to be a part of nvcodec plugin
for better interoperability.
Additionally, cuda runtime API header dependencies
(i.e., cuda_runtime_api.h and cuda_gl_interop.h) are removed.
Note that cuda runtime APIs have prefix "cuda". Since 1.16 release with
Windows support, only "cuda.h" and "cudaGL.h" dependent symbols have
been used except for some defined types. However, those types could be
replaced with other types which were defined by "cuda.h".
* dynamic library loading
CUDA library will be opened with g_module_open() instead of build-time linking.
On Windows, nvcuda.dll is installed to system path by CUDA Toolkit
installer, and on *nix, user should ensure that libcuda.so.1 can be
loadable (i.e., via LD_LIBRARY_PATH or default dlopen path)
Therefore, NVIDIA_VIDEO_CODEC_SDK_PATH env build time dependency for Windows
is removed.
separateColourPlaneFlag is mapped to separate_colour_plane_flag which
means Y, U and V planes are separately processed as monochrome sampled pictures.
So encoder shouldn't set that flag for normal 4:4:4 encoding.
Also for 4:4:4 encoding, NV_ENC_H264_PROFILE_HIGH_444_GUID profile must be
explicitly set.
Some presets are not always supported on all devices and will cause an error if
used. Specifically, the LOSSLESS presets are known to not work everywhere.
