ffdshow

To improve my understanding.

I installed ffdshow to run flv files.

I can now view flv files in Windows Media Player and Movica.

My question relates to how it works.

Before installing ffdshow the two programmes were useable (not for flv), so I assume that they have their own codecs installed somewhere? Yet they search for others?

Does ffdshow take preference over other codecs originally used by applications?

I am runnumg ffdshow using the defaults. Do I need to look further?

is ffdshow the best free series of codecs, best meaning most comprehensive?

Is ffdshow usually installed to superceed exisiting codecs and allow an application/s greater useage?

I wonder why media applications don't include ffdshow with their applications?

ffdshow is installed in program files (Vista). It looks like the applications must search for codecs, eventhough they have their own?