Re: [codec] Conformance with unusual sample rates

[John Ridges <[e-mail]>]

Thank-you for clarifying that. I also have another application where I 
need to use 16 ms frames and it looks like Opus-custom would allow me to 
do that.

John Ridges

On 11/18/2011 8:56 AM, Benjamin M. Schwartz wrote:
> On 11/18/2011 09:29 AM, John Ridges wrote:
>> Is it possible to create a conforming (and
>> thus unencumbered) Opus codec from the reference implementation that can
>> use a sample rate of, say, 44100 Hz?
> It depends what you mean.
>
> One answer is "no".  Opus always operates at a fixed nominal samplerate of
> 48000 Hz.
>
> Another answer is "yes", because you are of course always free to resample
> your inputs before encoding, and to resample the outputs after decoding.
> If you figure out a way to use less CPU by integrating your resampler into
> the decoder then that's just a trivial implementation detail.
>
> Another answer is "yes, in Opus-custom".  Opus-custom is a
> non-interoperable Opus-derived codec development system, defined as part
> of the Opus standard [1].  Opus-custom can be driven at different
> samplerates, including 44100 Hz.
>
> --Ben
>
> P.S. I do agree that clarifying our text on this point might be helpful.
>
> [1] http://tools.ietf.org/html/draft-ietf-codec-opus-10#section-6.2
>