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- DTMF decoder DEMO version
- Shima-nized Advanced Utilities - J.M. Shima
- Copyright (c) 1994-95 by James Shima
- All Rights Reserved
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- ▐▐▐▐ R E F E R E N C E M A N U A L ▐▐▐▐
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- » Type DTMF_D at the DOS prompt for a summary of options «
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- INTRODUCTION
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-
- * This program is capable of post processing DTMF tones and decoding the
- numbers from a given input sound file. The sound file has to be sampled
- at a 8kHz sampling rate. One application where DTMF tones are used
- is in the standard American telephone dialing system. The standard
- DTMF tones represent the numbers 1,2,3,4,5,6,7,8,9,0,*,# on a standard
- keypad interface.
-
- * The source sound file has to be binary or a Soundblaster 8-bit .VOC file.
-
- * This program accepts COMMAND-LINE ARGUMENTS that are passed to the
- DTMF decoder.
-
- * For a list of the arguments, type DTMF_D at the DOS prompt.
-
- * The DEMO only decodes a maximum of 5 numbers. Interested
- persons can purchase the full-blown REGISTERED version with no limitations.
-
- * An example of the input arguments are:
-
- Usage: DTMF_D <in_file> <thresh> <sblast>
-
- <in_file> --> input sound file name.
-
- <thresh> --> The threshold that the DTMF tones must exceed over the
- noise floor for detection (in dB). Typically, strong
- DTMF tones will be 20-40 dB stronger than the noise
- in the signal. However, noisy signals lower this
- signal-to-noise (S/N) ratio. The threshold parameter
- allows the user to set the S/N threshold for detection.
- NOTE: If nothing is entered, then the default thresh value
- is 20dB.
-
- <sblast> --> Set to this to a 1 for a Soundblaster .VOC file, else set
- it to 0. NOTE: If nothing is entered, the default is 1, i.e.
- a .VOC file is selected.
-
-
- IMPORTANT NOTES BEFORE USE
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- ** For the DEMO program, your input .VOC or binary file * MUST BE SAMPLED *
- at a 8kHz rate (no exceptions) for correct results.
- The industry standard for DTMF sampling is 8kHz, and this demo program
- uses that sample rate in its calculations!!
-
- ** A binary file consists of samples that are stored as 2's complement
- numbers. In other words, the samples take on values from [-128, 127].
-
-
- EXAMPLES OF RUNNING DTMF_D
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- DTMF_D dtmf800.voc 25 1 --> input file is dtmf800.voc, threshold S/N
- ratio is 25dB, soundblaster .VOC file type is
- selected.
-
- DTMF_D dtmf800.voc --> input file is dtmf800.voc, threshold DEFAULTS
- to 20dB S/N ratio, soundblaster file type
- is selected by DEFAULT.
-
- DTMF_D junk.dat 20 0 --> input file is junk.dat, thresh=20dB, binary
- file type is selected.
-
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- INCLUDED FILES
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-
- DTMF_D.EXE --> DTMF demo decoder.
- DTMF800.VOC --> DTMF number 1-800-555-1212 stored in a .VOC file.
- DTMF_1.VOC --> DTMF number 1 stored in a Soundblaster .VOC file.
- DTMF_7.VOC --> DTMF number 7 stored in a Soundblaster .VOC file.
- DTMF_D.DOC --> This file.
- REGISTER.DOC --> Registration form.
-
-
- REGISTRATION
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-
- ** For registration, please fill out REGISTER.DOC and see the DEMO screen.
- Specify media dispersement.
-
- The enhanced REGISTERED version of this program allows unlimited decoding
- of numbers, and offers many other features INCLUDING:
-
- 1) File types supported include: .VOC, .WAV, and raw signed binary files.
- Input file types are auto detected.
-
- 2) Fast detection mode, which doubles the speed of decoding.
-
- 3) Flexible sampling rate. The program adapts to sample rates other than
- the standard 8kHz.
-
- 4) Automatic logging of the resulting decoded numbers to a log file.
-
- 5) Multiple-file input mode, so uninterrupted decoding and logging happens
- without user intervention.
-
- ** REGISTERED users will also receive a DTMF generator program. This is
- a DTMF tone generator which allows you to create any DTMF sequence
- you wish. The program allows you to specify a DTMF number sequence,
- the sampling rate, and how long you want the pulses to be (in samples).
-
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- SOFTWARE LICENSE
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-
- The DEMO version of the DTMF decoder is shareware, and is free to be
- used for personal use only. This is true as long as the DEMO is
- not alterted in any fashion. Registered users will receive the enhanced
- version of the DTMF decoder and will receive documentation stating such.
-
- I have thoroughly tested this code and am not responsible for any mishaps
- that may happen when launched on your computer. The code was tested on
- a IBM compatible 25MHz 386DX PC with a Soundblaster Ver. 1.5, 8-bit sound
- card, running DOS 5.0. For optimal performance, DO NOT run this program
- while under Microsoft Windows.
-
- Every action has been taken to ensure an error-free program.
-
- Use this program at your own risk, as I assume no responsibility in your
- actions while you are using this program. Invoking the program is your
- compliance to this statement.
-
- Good luck!
-
- For more information,
- email: James Shima
- shima@cyberramp.net
-
-
- TRADEMARKS
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-
- Soundblaster and Creative Voice File are trademarks of Creative Lab's Inc.
- Microsoft Windows and DOS are trademarks of Microsoft.
-
-