improve README

README.md

@@ -1,10 +1,20 @@
 # denoiseMC - Motion-compensated denoising, based on MVTools
 
+This script requires [MVTools](https://github.com/dubhater/vapoursynth-mvtools).
+
 ```python
 def denoiseMC(clip, denoise_fn, radius: int = 2, search: int = 3, blksize: int = 16):
 ```
 
-`denoise_fn` takes only one parameter, the input video clip. If `blksize` is 8 or higher, the motion vectors are recalculated at half `blksize` after the initial analysis.
+## Parameters
+
+`denoise_fn` is a function accepting one parameter (the video clip to denoise). Check the examples to understand how to use this parameter.
+
+`radius` sets the temporal radius for motion compensation.
+
+`blksize` sets the block size for MVTools' `Analyse` function. If blksize is 8 or larger, the motion vectors will be recalculated with `blksize/2` to get finer results.
+
+`search` sets the search mode for MVTools' `Analyse` and `Recalculate` functions.
 
 ## Examples
 
@@ -16,6 +26,7 @@ from denoiseMC import denoiseMC
 def denoise(clip):
     return core.ttmpsm.TTempSmooth(clip, maxr=4)
 
+# Make sure to set radius=4 so TTempSmooth can use maxr=4
 denoised = denoiseMC(clip, radius=4, denoise_fn=denoise)
 ```
 
@@ -26,3 +37,7 @@ from denoiseMC import denoiseMC
 
 denoised = denoiseMC(clip, lambda c: core.ttmpsm.TTempSmooth(c))
 ```
+
+## How it works
+
+This script creates a sequence of motion-compensated frames around each source frame, and then runs your denoising function on this sequence of frames. The motion-compensated frames are then discarded and only the (now denoised) source frame is returned.