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Re: [codec] #8: Sample rates? 44.1kHz?

"Christian Hoene" <hoene@uni-tuebingen.de> Fri, 16 April 2010 04:45 UTC

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From: Christian Hoene <hoene@uni-tuebingen.de>
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Date: Fri, 16 Apr 2010 06:44:42 +0200
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Subject: Re: [codec] #8: Sample rates? 44.1kHz?
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Hi all,

>It might be useful to state that it is not recommended to use 44100 Hz, because the conversion to
>16kHz and 32kHz is computational more demanding than 48kHz and requires more power/time.

Currently, proposed codec run at sampling rates of 

BroadVoice: 8, 16 kHz
SILK: 8, 12, 16, 24 kHz
CELT: 32 kHz to 96 kHz.

I do have a question. In order to make the RTP handling and the resampling simpler, it might be useful to skip the 44.1kHz compression mode. If only 8, 12, 16, 24, 32, and 48 kHz sampling rates are used, then the RTP timestamp can be easily counted in 96 kHz units. Supporting 44.1 kHz would require fractions of time stamp units that are difficult to handle with. Also, the resampling take more computational resource if it has to be done at high quality.

Thus, my question: Is 44.1 kHz really much-needed or can we use 32 or 48 kHz instead?

Christian

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