[Asterisk-Users] Digium TheVoice recordings' sound terrible

[Benjamin on Asterisk Mailing Lists]

On Mon, 25 Oct 2004 11:06:40 -0400, Race Vanderdecken
<asterisk at vanderdecken.com> wrote:
>         If you have not gotten your answer yet;

I have tried the sox parameters Nicolas recommended and the files did
seem to be ok with that on my Powerbook. I am now waiting for the
feedback from the customer.

>         I would take the .gsm files that Digium produced

That's the trouble, the customer ordered them as WAV, not GSM. I am
sure if Digium had been asked to deliver them in GSM format they would
have been ok and matched the Asterisk sound library.

> or converted
> from the .WAV files and play them back on the Windows machine and then
> compare that quality to the WAV on the Windows box.

They checked the WAV files they got from Digium on their Windoze box
and they said that they sounded alright. I have to take their word for
it because I don't have any Windoze box. When I play them on my
Powerbook the volume too hight and it's not as clear as other WAV
files I have checked, but the only thing that matters is how they
sound when Asterisk plays them.

So, I have put those right into /var/lib/asterisk/sounds and let the
IVR menu play them back with Background(filename) and *that* sounds
terrible. The volume is much to high and the sound is like it was sent
through one of those guitar fuzz boxes.

So, I then tried to convert them to GSM format and while I was able to
get the volume down, the fuzz box effect got worse and worse the more
I tried.

Hence the question what sox parameters others have used in such situations.

>         The .gsm should sound the same on the windows box as on the
> phone. If the quality is worse then contact Digium.

All I expected is to get .gsm files that sound the same as the .gsm
files in the Asterisk sound library. I wasn't able to accomplish that.
Hopefully, with the parameters from Nicolas, they will be on par with
the Asterisk sound library now.

>         I used http://www.audioi.com/ 'Audio Converter and Ripper' to
> convert .wav to .gsm.

Thanks for the link. Funny that website doesn't mention platforms
anywhere at all. I guess it would be considered misplaced if I asked
them whether they have a Linux or OSX version ;-)

I was using sox, because that's what is sitting on the Asterisk server.

>         4. if there is much difference check the phone AUDIO CODECS in
> asterisk, you might be converting from GSM to G729 on the fly

That would be rather surprising because the caller to listen to the
IVR is coming in on a PSTN line via Zaptel ;-)

but thanks anyway, for you help.

I will report back when I know the feedback from the customer. If the
parameters posted by Nicolas did the trick, then I will update the
Wiki with that as an "if anything else fails" tooltip ;-)

rgds
benjk

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Tokyo, Japan.

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