[mythtv] [PATCH] MythPhone - prevent sending garbage video whenwebcam grabs smaller video than we want to send

Paul Volkaerts paul.volkaerts at lineone.net
Wed Jan 26 17:39:53 EST 2005


> I would be quite happy to recode it to allow input and output.
>
> Having synchronised in and out audio will be essential if we ever want
> to support accoustic echo cancellation.  I have been reading up on some
> algorithms, it's quite complicated though and there is no algorithm
> coded up (for free) that I can see.  It's something of a special case of
> the room correction stuff that I use in my hifi setup though.
>
> Will take a look as I get a chance

This would be really useful.  I coded using OSS first but that is not really
a very good interface for MythPhone, as I really wanted to use the
microphone as a clocking source, i.e. get the Microphone driver to kick my
process whenever it had 30ms worth of capture data. OSS cannot do this
though I believe Alsa can. The alternative is I have to wake-up my process
every 15ms and poll the microphone; and as a veteran of real-time
programming I really hate non-event-driven behaviour.

A common set of myth functions that handled mic audio too, and could provide
this synchronisation would be perfect.





More information about the mythtv-dev mailing list