[MPlayer-dev-eng] [PATCH] New slave command for loading video filters at runtime

[Reimar Döffinger]

On Sun, Apr 04, 2010 at 02:38:39AM +0900, Jehan Pagès wrote:
> as I have sent a patch for loading audio filters at runtime, I thought
> I might check if I could not do the same for video filters (though I
> don't have personally any use for such a feature, at the contrary of
> audio filters that I use a lot more now that I could bind key to load
> them) but I think some people find this interesting.

I think that generally just can't work, at least not as simple as that.
The problem is the buffer management: Any filter might allocate a buffer
on its own, it might pass on a internal buffer to the following filter
or it might just pass through a buffer that comes from a filter after
it or even from the VO (e.g. video RAM), it might add its own restrictions
(e.g. no following filter including the VO may modify it).
I think the only thing you can do is to destroy the whole filter chain
completely and build a new on from scratch, similar to what happens
on resolution changes.
Note that in some ways this may be better for audio as well, since af_add
e.g. has a known issue that it might end up doing needless format
conversions since an already loaded filter can not switch to processing
a different audio format.