Re: [Ccrtp-devel] ccRTP audio mixer

[maik.pichler]

Thx in advance for your answeres.

I tried to figure out what is meant with "sum the samples". (As I
mentioned within another posting I have only basic knowledge of RTP)

So if I have linear samples is it possible to mix the packets with the
ccRTP class outgoingDataQueue (putData) ?


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> The mixing algorithm is much simpler if you have or convert the packets
> to linear samples; you can then directly sum the samples of your
> incoming packets from all the sessions.  You should also mix each
> session separately so that it includes only the sum of packets received
> from the other sessions it is joined to and not it's own, so you do not
> carry back echo.  Of course if your doing multicast, then usually the
> mixing is distributed to the endpoints themselves.
>
> Other issues that make conferencing more interesting and complex include
> detecting packet energy level to determine who are the "loudest" or
> "active" speakers at the moment, so that you only sum the first (few)
> speakers rather than all sessions.  GNU ccAudio2 includes both codec
> functions to convert packet frames to/from linear, and functions to
> measure energy level.  Overall it would be very nice to see a generic
> conference server written with ccrtp.
>
> Dan Weber wrote:
> |
> | Simple.  Since ccrtp uses packet queues, appends all the rtp data to
> the | same queue.
> |
> | Dan
> |
> |
> | On Wed, 2 Mar 2005 address@hidden wrote:
> |
> |> I'm writing on my master thesis and looking for a rtp mixer. I found
> some |> hints that it may easily possible to implement with ccRTP.
> |> But I'm not sure! So has anybody experience how to implement an audio
> rtp |> mixer?
> |>
> |> maik
> |>
> |>
> |>
> |>
> |> _______________________________________________
> |> Ccrtp-devel mailing list
> |> address@hidden
> |> http://lists.gnu.org/mailman/listinfo/ccrtp-devel
> |>
> |
> |
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