IMPORTANT: This copy is partially disabled- it will not acknowledge 3 of the 16 touch tones. To obtain a full-featured copy, please register by sending $25 to me at this address:
Carl Huben
6929 Lee Crest Drive
West Bloomfield, MI
48322
Registered users will receive the latest (full-featured) copy of DTMF decoder, its documentation, and notification (either by mail or email, please specify) of future updates. I'll send updates to interested users by email (for free), or through the postal service if you send me a SASE.
Sorry, the source code is no longer available.
- Carl (gsmattes@vela.acs.oakland.edu)
-------------------------------- Begin Docs ----------------------------------
Touch Tone Decoder allows you to analyze a sound to determine whether touch tones are present, and if so, which ones. It also recognizes rings, busy signals, and the dial tone. Tones may be analyzed in real time, or recorded and then decoded.
I don't think the program requires much documentation. However, I should mention a few important points:
*** Decoding
• There are two decoding modes supported: asynchronous and real time.
- In asynchronous mode, pre-recorded sounds may be analyzed. Sounds can be loaded from AIFF files, pasted in, or recorded from within the program. The portion of the sample you wish to analyze must be highlighted. To decode the current selection, click the fourth button from the left (or choose "transform" from the decoding menu). The results are displayed in the text window. Analysis continues until either the end of the selection is reached, or the stop button is pressed.
- In real time mode, decoding is performed on-the-fly starting when the transform button is pressed, and continuing until the stop button is pressed.
• You can toggle the recognition of certain classes of tones by checking/unchecking the appropriate boxes to the right of the transform button. Here is why you might choose to do so:
- To prevent spurious recognition or tones you know will not be present.
- To speed up the algorithm. The algorithm runs fastest when only touch tones are chosen.
• You can set the sensitivity of the tone detection algorithm in the preferences menu. It is better to record louder tones than to increase the sensitivity, since false positives can be a problem at the high sensitivity setting.
*** Representation of Sounds / Making Selections
• Touch Tone Decoder features a graph of the current recording's average amplitude versus time in the small rectangle immediately below the buttons. The graph's function is two-fold: it allows the user to 'see' where the tones are within the whole sample, and it also indicates what portion of the sound is selected for playback or analysis.
• To select a portion of the sound for playback or analysis, position the I-beam cursor within the rectangle at one end of the selection, click the mouse button and, while keeping it down, move to the other end of the desired selection, then let go of the button. Your selection will be highlighted.
- NOTE: Double-click inside the rectangle to highlight the entire sample.
*** Recording Sounds
• Click the button with the red circle. Once you do this, the old recording (if there is one) is erased, and recording begins from the default sound input device. Recording continues until either the stop button (it has a square in the middle) is clicked, or the sound buffer is filled.
*** Playing Sounds
• The portion of the sample you wish to play must be highlighted. To play the current selection, click the button with the green triangle. Playing continues until either the end of the selection is reached, or the stop button is pressed.
*** Loading/Saving Sounds
• AIF files can be loaded, provided they are 8 bit, monophonic samples at either 11 or 22 khz.
• Sounds may be saved (as AIFFs), in whole or in part, by choosing the appropriate option from the file menu.
• Sounds selections may also be copied (from the edit menu), and pasted into the scrapbook or other applications.
*** Preferences
• Sound buffer- the size of the recording buffer in seconds.
• Sample rate- you can set the sample rate to either 22 or 11 khz.
• Play though- if checked, sounds are played through the Mac's internal speaker during a recording.
• Volume- You can set the volume to one of four levels, or to the system default.
• Tone sensitivity- You can choose from three levels of tone sensitivity.
• Colors- You can set the graph window foreground color, and the text window foreground and background colors from the pop-up menus.
• Record Protect- If checked, you will be warned before a recording is overwritten or lost (for example, when quitting).
• Text Protect- If checked, you will be warned before the text window is closed.
• Sound Creator- The four character creator ID used for sound files created by Touch Tone Decoder. The default creator is "SFX!"; any files saved using this ID will be opened by SoundEdit when double clicked.
• Text Creator- The four character creator ID used for text files created by Touch Tone Decoder. The default creator is 'ttxt'; any files saved using this ID will be opened by TeachText when double clicked.
*** Miscellaneous
• When you paste a sound into Touch Tone Decoder, the current sound (if there is one) will be overwritten, and the buffer will be resized to the length of the pasted sound.
• The Command-Period key combination is equivalent to clicking the stop button.
*** Problems
• If the program fails to recognize tones, they probably aren't loud enough. Try increasing the tone sensitivity in the preferences menu, or analyze louder tones. If that fails, make sure you are selecting a portion of the graph before pressing the transform button.
• If you have other problems, please contact me either by mail or email (addresses given below) with a *full* description of the problem. I'll try to fix it in the next version.
*** Distribution and (lack of) Warranty
Touch Tone Decoder 2.0 Demo may be freely distributed, as long as this text file is included.
No warranty is expressed or implied. I am not responsible for loss of data, time, money, life or other damages resulting from bugs or flaws in, or misuse of, either directly or indirectly, Touch Tone Decoder 2.0 Demo.
*** Okay...
Some features to be included in the next version:
• Applescript awareness.
• Recognition of user-specified tones
I will get to these soon. However, when I get to it depends in large measure on the response I get from the Mac community. If a lot of people express interest, I will get around to these upgrades sooner.
Thanks to everyone who's tested the program and made suggestions, but especially Rustle Laidman, for his endless testing and great suggestions. And of course, thanks very much to those who have registered.
If you have any bug reports, suggestions, and/or comments, I'd like to hear from you. My addresses are (in order of probable permanence):
• The Internet: gsmattes@vela.acs.oakland.edu
• US Mail: CCH, 6929 Lee Crest Drive, West Bloomfield, MI, 48322
• Compuserve: My ID is 72157,3506.
• America Online: My user ID is CarlHuben
***More information about signaling tones:
Touch Tones:
There are 16 touch tones. Most phones can only produce twelve of these, the familiar 0 through 9, #, and * tones. There are, however, four other touch tones, usually designated A, B, C, and D. Some modems and special purpose phones can produce these, but in general they are seldom encountered. The frequencies used for each touch tone are listed in the table below.
In North America, the minimum touch tone length is 50 milliseconds; the minimum separation between touch tones is also 50 milliseconds. Touch tones must follow these conventions to be processed accurately by the DTMF Decoder application.
1209 1336 1477 1633
_____________________
697 | 1 2 3 A
|
770 | 4 5 6 B
|
852 | 7 8 9 C
|
941 | * 0 # D
Dial Tone:
The standard dial tone is a continuous signal composed of equal amplitude 350 and 440 hz tones.
Rings:
There are two common types of rings, normal and PBX. DTMF Decoder recognizes both. The normal ring is a tone containing an equal amplitude mix of 440 and 480 hz tones. It is on for two seconds, and off for four. The PBX ring is spectrally identical to the normal ring, but is on for one second, and off for three.
It may seem surprising that the ring sound is just another DTMF tone, since it appears to chatter on and off during the actual ring ("B-r-r-r-r-r-r-ing"). The reason for this is simple: the difference frequency produced by the mixing of the two nearly equal frequencies that make up the ring is 40 hz, and so the 'volume' of the mixture dips and rises 40 times per second.
When DTMF Decoder encounters a ring when analyzing a recording, "RING" is written to the text window. It does not differentiate between the two rings.
Busy Signals:
Similar to rings, there are three common signals that share the same frequencies but differ in timing. These are the busy, local reorder, and toll congestion tones. They are composed of (again, an equal amplitude mix of) 480 and 620 hz tones. The busy signal is on for half of a second, and off for half of a second. The other two are shorter in duration and their off times are shorter, too.
***History:
Version 1.0 released 10/7/93
Version 1.1 released 12/3/93
• Snazzy finder icon added.
• Spinning cursor added to distract user during pauses.
• DTMF window comes up automatically after launch.
• Docs partially rewritten.
Version 1.2 released 12/16/93
• Support for black & white.
• No longer requires System 7.0 or above. I know for sure it runs on 6.0.7 and above.
• No longer requires a sound input device. This was something I just forgot to fix
earlier.
• Will run even if a printer is not chosen.
• Better color handling- allows user to customize the text and graph window colors.
• Superfluous data removed from pict resources.
• Play-through option added.
• Algorithm sensitivity made user-adjustable.
• Volume may now be set internally, or set to system default.
• No longer clobbers sound manager when it returns to finder.
• Support for multiple monitors.
• Docs overhauled.
Version 2.0 released 1/27/94
• New, assembly language decoding algorithm added. Handles real-time and asynch decoding.
