<div dir="ltr"><div>Ooops! I didn't reply-all...<br><br>When I look at the opus_defines.h, OPUS_BANDWIDTH_NARROWBAND, is defined
as '< 4 kHz bandpass'. I assume 'bandpass' in this case refers to a
'bandpass filter'.<br><br><a href="http://en.wikipedia.org/wiki/Band-pass_filter" target="_blank">http://en.wikipedia.org/wiki/Band-pass_filter</a><br><br></div>Looking at the briefly looking at the Opus RFC, I __think__ the 'bandpass' is applied per frame. Which means the 'center' of the bandpass filter could change frame to frame. Maybe I'm wrong and I need to slapped in the face with fish, but that's what it looks like it happening.<br><br></div><div class="gmail_extra"><br><div class="gmail_quote">On Tue, Feb 24, 2015 at 11:59 AM, Jean-Marc Valin <span dir="ltr"><<a href="mailto:jmvalin@jmvalin.ca" target="_blank">jmvalin@jmvalin.ca</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Can you explain what you mean by "center point"?<br>
<br>
Jean-Marc<br>
<div><div class="h5"><br>
On 24/02/15 11:30 AM, Tony wrote:<br>
> I have an audio device whose 'driver' gives me Opus encoded frames<br>
> using OPUS_APPLICATION_AUDIO and max bandwidth set to<br>
> OPUS_BANDWIDTH_NARROWBAND. How does Opus encoder decide the center<br>
> point of the 4K bandpass filter? Is it done frame by frame?<br>
><br>
> --<br>
> Tony<br>
><br>
><br>
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</blockquote></div><br><br clear="all"><br>-- <br><div class="gmail_signature">Tony</div>
</div>