Re: [codec] AD Evaluation of draft-ietf-codec-oggopus-09

"Ben Campbell" <ben@nostrum.com> Mon, 21 December 2015 22:21 UTC

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From: Ben Campbell <ben@nostrum.com>
To: "Timothy B. Terriberry" <tterribe@xiph.org>
Date: Mon, 21 Dec 2015 16:21:10 -0600
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Subject: Re: [codec] AD Evaluation of draft-ietf-codec-oggopus-09
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On 21 Dec 2015, at 15:43, Timothy B. Terriberry wrote:

> Ben Campbell wrote:
>
>> I think I see. The point is that you decode rate still does not match
>> the hardware rate, thus the resampling? OTOH, I now find myself 
>> confused
>> by "next highest supported rate above this". Does "this" refer to the
>> "hardware’s highest available sample rate"? So the decode rate is 
>> always
>> equal to or higher than the hardware playback rate?
>
>
> Correct (except possibly if the hardware supports rates higher than 48 
> kHz, in which case step 4 might apply).

Got it. But I still think the "this" is ambiguous (between "highest 
hardware rate" and 48khz). So I propose:

OLD:
Otherwise, if the hardware’s highest available sample rate is less 
than 48 kHz, decode at the next highest supported rate above this and 
resample.
NEW:
Otherwise, if the hardware’s highest available sample rate is less 
than 48 kHz, decode at the next higher Opus supported rate above the 
hardware rate and resample to the hardware rate.
END