[Freeswitch-users] Better results from mod_vmd

[Matthew Fong]

Hi Eric,
Thanks for these recommendations.

for vmd-not-panasonic-home-ans.wav changing MAX_FREQ to 1450 WORKED!

but I'm still having problems picking out the ~750Hz beep of sprint,
tmobile, and verizon. I tried first cutting POINTS and VALID in half, then
in half again, while also reducing MIN_AMPL in half but still no luck. I
assumed from the descriptions of each, that reducing the numbers would make
the algorithm less picky at finding a beep. Is this correct?

Any other recommendations on picking up these ~750Hz beeps? Thanks again for
the help.

--matt

On Mon, Aug 17, 2009 at 2:15 PM, Eric des Courtis <
eric.des.courtis at gmail.com> wrote:

> Matt,
>
> Okay the good news is vmd should be able to handle these cases. The
> bad news is for whatever reason they are not getting detected at the
> moment.
>
> vmd-not-panasonic-home-ans.wav is a sine at ~1400Hz you can change
> MAX_FREQ to 1450 and play with MIN_AMPL  if that still doesn't help.


> The following seem to use the same beep:
>
> vmd-not-tmobile.wav is a sine at ~750Hz but has a bit of noise
> vmd-not-sprint.wav is a sine at ~750Hz but has a bit of noise
> vmd-not-sprint.wav is a sine at ~750Hz but has a bit of noise
>
> You can try to play with these values:
>
> POINTS 32
> VALID 22
> MAX_CHIRP 22
>
> If that doesn't work let me know I will try to improve the algorithm
> to detect the providers.
>
> Cheers!
>
> Eric des Courtis
>
>
>
> On Mon, Aug 17, 2009 at 1:52 PM, Matthew Fong<mattdfong at gmail.com> wrote:
> > Hi Eric,
> > Thanks for the response. I had tried emailing you @brenbria.com and the
> > email had bounced, thanks for responding to my mail.
> > If you'd be interested I .zipped up my sample voicemail beeps
> > at http://bandcon.hellohunter.com/vmd_wav.zip
> > I'm relatively new to telephony, but can you point me in the right
> direction
> > for figuring out if the beeps are sinewaves. About as far as I've come
> with
> > audio is being able to open the .wav files in audacity. Any website
> >  recommendations I can read? Thanks so much.
> > --matt
> >
> > On Mon, Aug 17, 2009 at 10:29 AM, Eric des Courtis
> > <eric.des.courtis at gmail.com> wrote:
> >>
> >> Matt,
> >>
> >> You must first capture the audio beeps and verify that they are sine
> >> waves. If not, simply tweaking the algorithm will not give you better
> >> results.
> >>
> >> It might be possible to use FFT and I would be happy to help you
> >> implement such a solution but keep in mind FFT is very very demanding
> >> on the hardware. Ideally what you want to find out is what functions
> >> was use to generate the beep in the first place so that it can be
> >> detected. Is it two sines waves like in DTMF? Or something more
> >> complex?
> >>
> >> Anyway my email is eric.des.courtis at benbria.ca.
> >>
> >> Cheers.
> >>
> >> Eric des Courtis
> >>
> >> On Mon, Aug 17, 2009 at 12:26 AM, Matthew Fong<mattdfong at gmail.com>
> wrote:
> >> > I tried emailed Eric, seeking advice on this, but his email (the one
> in
> >> > the
> >> > source code) is bouncing email (invalid user), so thought I would ask
> >> > here
> >> > instead. If anyone has eric's new email address, I'd be interesting in
> >> > it.
> >> >
> >> > I did some tests with mod_vmd this afternoon, but I'm only finding
> about
> >> > 33%
> >> > of the voice mail beeps and did have 1 false-positive in my test of
> >> > 7 voice
> >> > mail machines. I've recorded the audio of the session in .wav files
> that
> >> > were both successful and not, as a comparison. I can upload the .wav
> >> > files
> >> > if they would be useful.
> >> > mod_vmd works great for voicemails of Skype Users, and kall8.com, but
> >> > has
> >> > issues dealing with mobile phone carriers.
> >> > sprint - not successful
> >> > tmobile - not successful
> >> > verizon - not successful
> >> > panasonic home answering machine system - not successful
> >> > kall8 - SUCCESS
> >> > skype - SUCCESS
> >> > I'm wondering if you can recommend a simple fix, like changing some of
> >> > the
> >> > constants like MAX_FREQ, or MIN_TIME at the top of the mod_vmd.c
> source
> >> > file, or if better success requires more complex analysis.  Do you
> have
> >> > any
> >> > recommendations on how this might be done? Listening to the .wav's
> >> > its apparent the beeps are not as loud for the mobile phone carriers
> as
> >> > they
> >> > are with skype and kall8. Any guidance would be greatly appreciated.
> >> > --matt
> >> > hello hunter
> >> > http://www.hellohunter.com
> >> > voice broadcasting & hosted dialer
> >> > _______________________________________________
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> >> > FreeSWITCH-users at lists.freeswitch.org
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> >
> >
>
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