opus - Jan 2011 - Artifacts in One Channel of Stereo C55x Implementation

Hi guys,

I am on a C55x stereo implementation of CELT 0.7.1; I am using 100 sample
frame size and writing 58 Bytes per Packet. At the output of the decoder I
see one channel reconstructed perfectly, but the other channel has random
corruption that appears to be a sinusoid with a period of the frame size.
The artifact is non-periodic and appears to happen randomly during the audio
stream.

Anyone ever run across this? Have any insight?

thanks
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I guess the first question is whether you can reproduce the problem on a 
PC with the same code. If not, then the most likely issue is a 16-bit 
integer overflow. CELT *attmpts* to only use the "int" type for values
that won't overflow a 16-bit int. However, because we have no 16-bit 
platform to test, it's likely that we missed something.

Cheers,

	Jean-Marc

On 11-01-31 03:34 PM, Bob Bang wrote:
> Hi guys,
>
> I am on a C55x stereo implementation of CELT 0.7.1; I am using 100
> sample frame size and writing 58 Bytes per Packet. At the output of the
> decoder I see one channel reconstructed perfectly, but the other channel
> has random corruption that appears to be a sinusoid with a period of the
> frame size.  The artifact is non-periodic and appears to happen randomly
> during the audio stream.
>
> Anyone ever run across this? Have any insight?
>
> thanks
>
>
>
>
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> celt-dev mailing list
> celt-dev at xiph.org
> http://lists.xiph.org/mailman/listinfo/celt-dev