I want to create a custom GPAC filter which is going to be a decoder at later stage.
From [this](https://github.com/gpac/gpac/wiki/filters_general#external-filters) document, it says we can load external filters from default module folder.

So I have created a folder "test_filter" in the gpac_public\modules folder and added a makefile and gf_test_filter.c source file in it.
Also I have added `PLUGDIRS+=test_filter` in the makefile of modules folder to enable build of test_filter.

But in the build log I am not seeing this file getting compiled anywhere and I am not able to use this filter with the gpac command.
It gives following error 
```
Failed to find filter "testfilter"
Closest filter names:
- flist
```
Need help implementing a custom filter
This is a GitHub Issue
repo:gpac
owner:gpac
Title : Need help implementing a custom filter
Issue date:

--- start body ---
I want to create a custom GPAC filter which is going to be a decoder at later stage.
From [this](https://github.com/gpac/gpac/wiki/filters_general#external-filters) document, it says we can load external filters from default module folder.

So I have created a folder "test_filter" in the gpac_public\modules folder and added a makefile and gf_test_filter.c source file in it.
Also I have added `PLUGDIRS+=test_filter` in the makefile of modules folder to enable build of test_filter.

But in the build log I am not seeing this file getting compiled anywhere and I am not able to use this filter with the gpac command.
It gives following error 
```
Failed to find filter "testfilter"
Closest filter names:
- flist
```
--- end body ---
