Messages in this thread | | | Date | Fri, 10 Jan 2003 08:52:18 +0200 | From | Matti Aarnio <> | Subject | Re: [Asterisk] DTMF noise |
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On Thu, Jan 09, 2003 at 05:32:51PM -0600, David D. Hagood wrote: > Well, I found out that while we have the DTMF test tape at work, it is > exactly that - a cassette tape that is copyrighted. So, no easy/legal > way to make it available for testing...
What does such tape contain ? - DTMF tones buried in various degrees of distortions, which should be decodable ? - DTMF tones buried in varying noises which should not be decodable ? - Other multi-tone signals which should not decode ?
For the last, I know of cases where test was done by playing a radio station on the decoder for 2-3 days, and seeing when does it trigger DTMFs (if ever).
For that matter, the Linux kernel ISDN audio DTMF detection is exactly of the last variant.
/Matti Aarnio - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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