[vorbis-dev]Newbie question

Rob D rddone at att.net
Fri Jan 17 07:23:34 PST 2003



 Hello there,
I am a new member here, and of course i have a question first thing.

About myself: I have been programming for nearly 20 years, have been degreed
for nearly 10, currently work programming satellite system simulators for
the AirForce, and enjoy programming so much, nearly half of my free time is
spent programming too.

I recently used the SDK to add ogg support to an existing mp3 product. It
has mp3 to ogg conversion, mp3 to wav, ogg to wav, and wav to ogg conversion
support.

The player has hardware volume for instantaneous volume, and has decoder
volume for saving a volume/eq settings per album so they play back
relatively similar sounding. The mp3 version has been working this way for
several years, but cannot figure out how, (or if there is a way) to add
similar support for the ogg decoder.

After reading through all the docs and coming up empty, and perusing the msg
archive, and finding that ogg not currently support EQ settings yet, but
maybe someone knows how to do volume for now.

I realize that I could use the volume as a scaling value for the hardware
volume, but that would rule out volume increase for a quiet album, and would
require 'downgrading' the mp3 decoder to work the same, or some screwy
programming to support doing it differently per decoder.

If there is no existing way to achieve volume control, it would seem I could
loop through PCM buffer and multiply all values by volume ratio before
passing buffer to sound card, but that would be rather CPU intensive, and
would rather scale some variable used for building PCM buffer when
converting from freqency values.

I would be interested in being part of the EQ additions if/when it gathers
enough interest.

For those interesting in seeing the product this is referring to, I have had
a shareware version available for about 3 years, and there is a BETA version
with ogg support at:

http://rbdone.home.att.net/rsmp3ogg.zip

It is about 1MB. There are about a dozen small things I have to clean up
before I can remove the BETA status,  but is very close. It will complain
about playlist, bakup, and skin files load failure, and some of the tools
are still hardcoded as mp3, and wont work for ogg, but the player works
great.

Thanks in advance
Rob D

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