[gst-devel] Passing Custom Events

[Wim Taymans]

On Wed, 2005-01-26 at 14:05 +0100, Benjamin Otte wrote:
> On Tue, 25 Jan 2005, Thirupathiah Annapureddy wrote:
> 
> > Hi All,
> > I have developed two basic elements src and decoder specific to our
> > hw. They use normal gst provided logic to pass data when they are
> > connected to non-custom elements. When both of these are connected, i
> > want to exchange some unique information between them so that data
> > flow is handled entirely at hw level.
> > I thought of sending a custom event from one element to another
> > element to exchange this unique information. To create a custom event,
> > should i extend GstEventType or i can use any event# higher than
> > GST_EVENT_TAG.
> >
> If you want to create custom events, you should use GST_EVENT_ANY and use
> a unique name for the GstStructure in that event.
> Off topic: Your idea of extending the enum doesn't work, because if
> someone else has the same idea, you get a collision.
> 
> OTOH I'm not sure you want to use events here. Wouldn't it be better to
> negotiate the link between the two elements to a different format (say
> "application/hw-passed-stuff") and just pass control information over
> that link?

Indeed, this is the solution I would suggest as well, pass the control
information about where the buffer is using the buffer passing
mechanisms instead of using custom events. You can define your own
layout for the buffer contents and define a unique caps for that layout.
This will also make sure that your element is not linked to an element
that does not understand this control information. There is no such
guarantee for events.

Wim

> 
> Benjamin
> 
> 
> 
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-- 
Wim Taymans <wim at fluendo.com>