multi audio track combine

[Richard]

Thanks all,

The scenario is odd...  Its a intercom with some funky features.

3 ALSA inputs/outputs for headsets/microphones, all audio from all
microphones should go to all earpieces.

There is one special case input; A microphone is placed in the ambient
noise (in an aircraft)
The audio is inverted and added to the other 3 headset outputs - this
should give Active noise cancellation; or some effect close to it.

It is easier to do using discrete op-amps, but this is more fun :D

Richard
 On Aug 19, 2012 8:03 AM, "Emile Semmes" <emile.semmes at e6group.com> wrote:

> On 8/18/2012 12:23 PM, Tim-Philipp Müller wrote:
>
>> On Sat, 2012-08-18 at 17:43 +0100, Richard wrote:
>>
>>  Is there a component that is capable of combining/mixing multiple
>>> audio tracks in to one? I am reading audio from multiple ALSA devices
>>> and need to combine in to one stream and then output to multiple audio
>>> sinks.
>>>
>> Perhaps the "adder" element is what you're looking for? If not, maybe
>> the interleave element?
>>
>> Cheers
>> -Tim
>>
>> ______________________________**_________________
>> gstreamer-devel mailing list
>> gstreamer-devel at lists.**freedesktop.org<gstreamer-devel at lists.freedesktop.org>
>> http://lists.freedesktop.org/**mailman/listinfo/gstreamer-**devel<http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel>
>>
> Tim,
>
> You beat me to the punch. I second using adder too.
>
> Can you just have a pipeline from one alsasrc directly to the alsasink or
> do you need something like an output-selector for dynamic alsasink
> selection? Is this on the same device for immediate playback or can you
> save this to a file for later playback? There are a couple of ways to skin
> this cat.
>
> Note: these are prototype pipelines. I haven't tested them.
>
> Assuming you're using multichannel inputs, you could try using the
> interleave and deinterleave elements but that's kinda hackish
> alsasrc device="hw:1,0" ! deinterleave name=d1 \
> alsasrc device="hw:1,1" ! deinterleave name=d2 \
> interleave name=i \
> d1.src0 ! i.sink0 \
> d1.src1 ! i.sink1 \
> d2.src0 ! i.sink2 \
> d3.src1 ! i.sink3
> ... and then the reverse to get to your alsasink. If you need to swap
> inputs to outputs, you'll have to throw in output-selectors. That's going
> to be a pretty complex pipeline, but it may do the trick. (This actually
> sounds like fun. Let me know if you need help doing this one)
>
>
> For later playback, if you can mux them into a quicktime container. Your
> pipeline would look something like:
>
> alsasrc device="hw:1,0" ! queue ! mux.audio_00 \
> alsasrc device="hw:1,1" ! queue ! mux.audio_01 \
> alsasrc device="hw:1,2" ! queue ! mux.audio_02 \
> qtmux name=mux ! filesink
>
> You might have to do some tricks with qtmux so you can play it back.
> qtdemux was complaining about an empty atom during demuxing.
>
> Have fun,
> Emile
>
> ______________________________**_________________
> gstreamer-devel mailing list
> gstreamer-devel at lists.**freedesktop.org<gstreamer-devel at lists.freedesktop.org>
> http://lists.freedesktop.org/**mailman/listinfo/gstreamer-**devel<http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.freedesktop.org/archives/gstreamer-devel/attachments/20120819/aa662e1e/attachment.html>