Problem about cudaCreateChannelDesc

Dear all,
I have some question about cudaCreateChannelDesc,I have read the CUDA_runtime_api.h.What does x,y,z,w mean?
Is it the bit depth?
If a bmp file ,so I read the API like cudaCreateChannelDesc(8,8,8,8,cudaChannelFormatKindUnsigned),because all RGB and alpha channel are 8 bits.
So if the data is 10 or 12 bit,I can run the API lik cudaCreateChannelDsec(10,10,10,10,cudaChannelFormatKindUnsigned)?

http://docs.nvidia.com/cuda/cuda-runtime-api/group__CUDART__HIGHLEVEL.html#group__CUDART__HIGHLEVEL_1g655725c27d8ffe75accb9b531ecf2d15

If you search for it in the cuda programming guide, you can find several examples.

There are also cuda sample codes which provide examples.

Is there any clear explanation?The CUDA_Runtime_API.pdf in 229 page write (x —— x component)。So does it mean bit depth?

Did you click on the link I gave? It says:

“Returns a channel descriptor with format f and number of bits of each component x, y, z, and w.”