[asterisk-dev] how does a channel driver know the result of codec negotiation ?

[Kevin P. Fleming]

Luigi Rizzo wrote:

> I suppose (but again, have no idea) that for audio codecs, asterisk
> uses the .capabilities field of the struct ast_channel_tech to do
> the matching, and because asterisk itself does the transcoding there
> is no need to propagate the choice to the channel driver.  But for
> video the situation is different.

That is exactly correct; the channel driver tells the core what
format(s) the channel can supply/accept, and Asterisk does the rest. The
channel driver is never informed of any changes in format that will
occur to the media once they leave the channel driver.

Why do you say that the situation is different for video?

-- 
Kevin P. Fleming
Director of Software Technologies
Digium, Inc. - "The Genuine Asterisk Experience" (TM)