[Vorbis] bitrate limits don't work with -q settings?

[Nic Watson]

Thanks for the quick response.  To get versioning out of the way, I 
recompiled the libraries and oggenc from mainline svn yesterday night. 
I see the same results.

Unfortunately, I am stuck on a stupid transport.  On the IRiver players, 
any time the bitrate dips below 96kbps, you'll hear a click or pop, and 
the song will usually end.  -q3 -m 96 doesn't work.  Is there any way to 
use VBR and absolutely guarantee that the bitrate won't fall below a 
certain level?  I figured that's what the bitrate_hard_min option was 
for, but it seems to have the opposite effect.

Nic

Ralph Giles wrote:

> On Tue, Dec 28, 2004 at 10:23:50PM -0500, Nic Watson wrote:
> 
> 
>>The problem I'm seeing is that oggenc's VBR encoding doesn't seem to pay
>>attention to any sort of bitrate limitation, either the -m or
>>bitrate_hard_min settings.  It isn't that it temporarily dips below the
>>minimum; the average for the whole (in this case, easily compressible)
>>file is 10-20% too low.
> 
> 
> Are you complaining that the encoder does too good a job? :-)
> 
> The managed bitrate modes use a different engine from the standard 
> constant-quality engine, and is mutually exclusive with -q. You have
> to turn it on with -b or in more recent versions of oggenc with 
> --managed.
> 
> 
>>I see roughly the same results on an old 1.0.1 version of oggenc as well
>>as a new vorbis 1.1-linked one I found on rarewares.org.
> 
> 
> The managed bitrate handling was changed in the 1.1 release; I don't 
> know if the rarewares oggenc is the updated version from svn or not, so 
> it may be using the same logic as the 1.0.1 version.
> 
> If it's underruns you're worried about you probably shouldn't be using a 
> managed mode; -q will do a better job. You really only need this if 
> you're on some stupid transport that really can't handle the normal vbr 
> streams.
> 
>  -r
>