[pulseaudio-discuss] RTP delay and another problem

[Lennart Poettering]

On Tue, 30.06.09 12:20, Jonathan Abrams (jonathan.abrams at windriver.com) wrote:

>>> 2) Because I sometimes need to connect the RTP stream (being passed   
>>> through a null sink) to a device instead of an application, I use a   
>>> 'pacat -r -d <deviceid1> | pacat -p -d <deviceid2>' loopback. This
>>> will     
>>
>> The clocks of those two devices don't need to be in sync, so this must
>> dropout sooner or later. 
>>
>> But why are doing this anyway? You can just load module-rtp-recv on
>> the right sink and have it deal with the clock deviations.
>>   Lennart
>>
>>   
>
> Thanks very much for the response Lennart.
>
> The reason we are doing this is because we are creating an audio  
> management system that manages audio devices on different logical audio  
> 'buses'. In most cases, applications can connect to a logical bus by  
> connecting to the source/sink that represents the bus on that host. In  
> order to use RTP this way, we need to make it appear in pulseaudio as  
> sources/sinks, (not as source-outputs/sink-inputs). Tying RTP streams to  
> null sinks works fine for the most common use case (connecting an  
> application to a 'bus'), but we also need to be able to 'bridge' buses.  
> This is where connecting sources directly to sinks is required. We are  
> doing this using pacat and pipes. But obviously this is insufficient due  
> to the source and sink having different clocks. The FAQ on the  
> pulseaudio website recommends using the pacat pipe method for connecting  
> a microphone directly to speakers. Does it work in that scenario because  
> the microphone and speakers use the same clock? Is there another way to  
> connect a source to a sink that is clock agnostic?

Does the FAQ really say that? It shouldn't. Dunno whho added this
there.

Uh, that part of the FAQ is really misleading. Also, not sure why sox
is used there. I have now deleted this.

Lennart

-- 
Lennart Poettering                        Red Hat, Inc.
lennart [at] poettering [dot] net
http://0pointer.net/lennart/           GnuPG 0x1A015CC4