[Live-devel] Transcoder Question

[Susanne Lefvert]

Thank you for answering my questions. However, I still get the same 
result after changing to 2 for big-endian. Any other ideas?

Thanks,

Susanne



On Mon, 31 Jan 2005, Ross Finlayson wrote:

> 
> >I am trying to develop an audio transcoder using the live.com streaming
> >media library.  The goal is to receive L16 RTP audio streams and transcode
> >them on the fly to PCMU audio, then forward the new streams to a different
> >multicast address.  I found the uLawFromPCMAudioSource that already exists
> >in the library and tried to use that filter for the transformation.
> 
> Susanne,
> 
> I didn't have time to look at your code in detail, but one thing you should 
> note is that in the "audio/L16" RTP payload format (a 16-bit PCM RTP 
> stream), audio samples are sent in *network byte order* - i.e., big endian.
> 
> Therefore, when you create the "uLawFromPCMAudioSource" filter that you'll 
> feed this incoming PCM data into, you should set the "byteOrdering" 
> parameter to 2, to indicate that the input data is in big-endian order.
> 
> >Also, I am planning on adding down-sample code so I can transform
> >L16 - 16kHz -> PCMU - 8KHz.  Would a new filter be the appropriate place
> >for me to add that?
> 
> Yes, I think so,
> 
> 
> 	Ross Finlayson
> 	LIVE.COM
> 	<http://www.live.com/>
> 
> _______________________________________________
> live-devel mailing list
> live-devel at lists.live.com
> http://lists.live.com/mailman/listinfo/live-devel
> 
>