[gst-devel] Notes about docs/random/negotiation

[Benjamin Otte]

Anyway, you need to modify the element anyway and need to add a
get_caps functions you can then use gst_pad_renegotiate anyway.
The only place where gst_pad_try_set_caps would be useful IMO is for
proxying.

Benjamin


On Mon, 29 Dec 2003, David Schleef wrote:

> On Tue, Dec 30, 2003 at 01:11:15AM +0100, Benjamin Otte wrote:
> > :p
> > Nice that you answer all the questions after I wrote the solutions ;)
> >
> > On Mon, 29 Dec 2003, David Schleef wrote:
> >
> > > Elements don't need a src_link() function to use try_set_caps().
> > >
> > Every pad that has non-fixed template caps needs a src_link or a get_caps
> > function, because the sink may do renego.
> > Every pad that has fixed template caps doesn't need to call try_set_caps.
> > Therefore every element that uses try_set_caps but doesn't have a src_link
> > function is broken.
>
> Or a getcaps function.  Which is the better solution, imo.  If a
> decoder reads the stream data and decides on exactly one output
> format, that format should be reflected in the getcaps function,
> because that's the only format the element is willing to accept
> on its source pad.  If the getcaps function (or pad template)
> pretends to support more formats, but then rejects all but one of
> them in the src_link function, I think that's broken.  It requires
> more code _and_ makes autoplugging more complicated.
>
> It might be wise to consolidate such behavior in a GstPad subclass
> in 0.9.
>
>
>
> dave...
>
>