@ Petrz
I'm glad you've got things working.
When I uninstalled in_mp4.dll, Winamp would not load MP4 files into the Library. I don't use any 3rd party codecs.
Are you sure you can tag MP4 files in Winamp when in_mp4.dll is not installed?
@ Aminifu
My tests show that if MP4 is not included in the extension list of in_mp4.dll, tags are not written to file.
Maybe you moved MP4 from in_mp4.dll to in_dshow.dll? I did, when I still played videos using these instructions:
http://forums.winamp.com/showthread....id=155680#mp4v
I am able to either play MP4 files or tag them, but not both. Maybe Petrz has found a way.
Long ago, I gave up on trying to write tags to video files.
Instead, I satisfied myself with using the filepath to provide basic tags via the "Smart" option in the Watch Folder Settings.