[Live-devel] PCM data gets corrupt during transport

[Marlon Reid]

Hi Ross,
 
I found the problem and manage to fix it even though I am not entirely
sure of the reason for it.
 
I have my own custom AudioRTPSink for PCM data. Removing the
MultiFramedRTPSink::doSpecialFrameHandling call from the
doSpecialFrameHandling function in my derived AudioRTPSink solved the
problem. I can only speculate that one of the parameters of the function
might have been incorrect.
 
In any case, removing this call gives me crystal clear sound and it
seems to have no adverse effect on my application.
 
Thanks for you help.
___________________________________
  

Marlon Reid 

 

Web: www.scansoft.co.za <http://www.scansoft.co.za/> 
Tel:  +27 21 913 8664
Cell: +27 72  359 0902 
 
 

________________________________

From: live-devel-bounces at ns.live555.com
[mailto:live-devel-bounces at ns.live555.com] On Behalf Of Ross Finlayson
Sent: 03 February 2012 10:22 AM
To: LIVE555 Streaming Media - development & use
Subject: Re: [Live-devel] PCM data gets corrupt during transport



	I am experiencing a problem that has me stumped.  My application
uses Live555 to stream PCM data over a network.  The problem is that the
data received on the client side is corrupt.  The bottom half of the
right channel contains noise.  If you take a look at the image hosted
here : http://www.freeimagehosting.net/q1cgw you will see what I mean.
The first file is the PCM data directly before transport (obtained from
the input buffer in AfterGettingFrame1 in my FramedFilter, the second
PCM file is data directly after transport (obtained from the input
buffer in AfterGettingFrame1 in my MediaSink).
	 
	My only conclusion is that I must be doing something wrong that
causes the transport to add this noise to the right channel during
transport, but I cannot figure out what.  Can you perhaps guide me in a
direction?


One possibility that comes immediately to mind is that you're not
setting "fFrameSize" correctly (and/or are not copying the correct
number of bytes) in your source or filter objects.  Remember that PCM is
usually 16-bits per sample, so its size in bytes is 2x the number of
samples.


Ross Finlayson
Live Networks, Inc.
http://www.live555.com/ 

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