<div dir="ltr">Thanks, Gregory. That's perfect, exactly what I wanted to know.<div><br></div><div>- Larry</div></div><div class="gmail_extra"><br><div class="gmail_quote">On Thu, Nov 6, 2014 at 2:06 PM, Gregory Maxwell <span dir="ltr"><<a href="mailto:gmaxwell@gmail.com" target="_blank">gmaxwell@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><span class="">On Thu, Nov 6, 2014 at 8:55 PM, Larry Fenske <<a href="mailto:opus@towanda.com">opus@towanda.com</a>> wrote:<br>
> I'm a bit confused about VBR with Opus. I see that the default is VBR,<br>
> but I don't see any way to specify a quality setting. I can set a<br>
> target bitrate, but that's definitely not what I want; I want a constant<br>
> quality level, like "-q" in oggenc, and for the encoder to select<br>
> bitrates based on the desired quality.<br>
><br>
> For example, for playback through earbuds or laptop speakers, I wouldn't<br>
> need anything better than low quality; through good headphones or decent<br>
> stereo speakers, medium quality; and for playback through $5000<br>
> speakers, high quality. Bitrate is not relevant in these cases, except<br>
> I don't want the file to be larger than necessary for the desired quality.<br>
<br>
</span>The VBR settings are 'constant quality'. Bitrate is just used as a<br>
real-world unit indexed against a large corpus of diverse content.<br>
E.g. bitrate 128 is the quality that got the average rate for the<br>
whole corpus to 128.<br>
<br>
This avoids problems with an opaque quality setting having no external<br>
meaning (and drifting over time and/or having to add crazy values like<br>
-2 later ) and only making sense relative to itself.<br>
<br>
If you'd like, you can just imagine that the bitrate numbers in VBR<br>
mode are "quality" scaled by a somewhat funny 512kbit/sec/channel.<br>
</blockquote></div><br></div>