Does compiling Decord from source depend on FFmpeg?

Hi Decord team,
Does compiling Decord from source depend on FFmpeg, or is FFmpeg required only for compiling the CUDA version of Decord?
When I enabled CUDA compilation, the following error was reported(command: `cmake .. -DUSE_CUDA=ON -DCMAKE_BUILD_TYPE=Release -DUSE_CUDA=/usr/local/cuda`):
```sh
CMake Error at cmake/modules/FFmpeg.cmake:27 (message):
Unable to find FFMPEG automatically, please specify FFMPEG location
Call Stack (most recent call first):
CMakeLists.txt:91 (include)
```
I would greatly appreciate it if you could reply.