The Very Best of Atari Inside

home *** CD-ROM | disk | FTP | other *** search

/ The Very Best of Atari Inside / The Very Best of Atari Inside 1.iso / sharew / musik / vox_demo / readme < prev next >

Wrap

Text File | 1994-02-05 | 31.5 KB | 622 lines

Voxx, The 16-Band Vocoder for ATARI Falcon 030 (c)1994 Hans Achim Mueller Short User's Manual for Demo_Version. INDEX ----- 1.- Introduction 2.- Installation & DEMO-Restrictions 3.- Description 4.- Operation 5.- Some Useful Hints 6.- Specifications 7.- Availability 1.- Introduction This is the Demo-Version of a 16-Band Vocoder effect for the ATARI Falcon030 computer. This program is Public Domain and free of charges. It can be copied and distributed, if it is done entirely, without any changes in the code or this text! Any distribution of mutations, improvements, cracks etc. of this program without my written permission is illegal! *************************** IMPORTANT ********************************* I do not assume any responsability, in any form, for direct or indirect damages, that may result from the use of this programm! *********************************************************************** The german version of this text will follow soon (February). 2.- Installation This Demoversion of Voxx should have the following files: File Name Lenght VOXXDEMO.PRG 46653 VOXXMENU.RSC 2454 VOXX_UPR.RSC 52006 VOXXENV0.RSC 65438 VOXXENV8.RSC 61982 VOXX_PAN.RSC 49128 VOXXMIX0.RSC 65438 VOXXMIX8.RSC 61982 VOXX_DOC.TXT (This text) Be sure these files are the same length (where specified) in other case you have a modified and therefore an ILLEGAL copy! Voxx requires 512 KB of free memory and runs only on ATARI Falcon030 wih a RESOLUTION of at least 640 * 480 and at least 16 COLORS! (VGA Monitor or similar). If you do not have these requirements please write me a postcard telling your configuration in order to check if it will be available and when. IMPORTANT: Before you start the program please read carefully this documentation to avoid startup problems (there are some) that I am trying to solve now. Furthermore a Vocoder is a complex effect that requires some hints and knowledge to satisfy that what is expected from it! 2.1.- Restrictions in the DEMO-Version: The purpose of a Demo-version is to let the user take an idea of what a program can be or do. After deep thoughts about what should be in the Demo-version of Voxx, I decided to release it at the conclusion of it's developement. I could have released a demo much earlier, but it's screen would not have been so impressive like it is now!. Actually the Beta-version is ready and this demo is a slightly restricted version of it. The restrictions are: a.- The options marked with *** are disabled and these are: the Load and Save File options, Program Store. b.- The program changes (cycles) every 30 seconds to the next user program. The user programs are uneditable presets (program Store disabled) and some programs are intentionally missadjusted to sound not so good. User adjustments on the actual settings are possible at any time, but at least in 30 seconds will be overwritten by an automatic selected program. If any accesory is selected and the 30 seconds count is reached the accesory window will be overdrawn by the new adjustements. This is intentionally and harmless. Closing the accesory you get a clean Voxx-screen again. To run, copy all files to a FOLDER and be sure the PATH is set to the application when starting the program. 3.- Description For all those who do not know what is a Vocoder and how it operates, or those that not have a lot of experience with them, I will try to explain it as simple as I can: Apparently the Vocoder is a Military residual product that was developed to encode the speech in a way that it was impossible to be understood by other listeners until they also had a Vocoder with the same configuration. The function of a Vocoder is to split the speech (FORMANT) or any sound into several Frequency-Bands (eg. to analyze each band) and apply the amount of signal in each band to another sound (CARRIER), that also is splitted in Frecuency-Bands. In other words, the spectrum of the speech was used to FORM the sound of the CARRIER. The most analog Vocoder is our own Vocal-System that is composed of: a.-Vocal chords: who produce the voice (Oscillators) b.-Mouth: that forms the vocalization (Filtering and Noise) The vocal chords produce a sound (voice) that only can vary the pitch but not the sound character. The waveform of this sound is nearby a Pulse-Wave eg. rich in Harmonics. The sound character is given by our mouth formation (Vocalization). The form and volume of our mouth-cavity (including tongue position and mouth aperture) produce a resonance cavity that acts like a filter on the voice. Any variation of our mouth is a variation in the filter parameters, so we can say that we have a Time-Variable-Filter of more complex structure than known of analog synthesizers. In addition the same airflow that excites the vocal chords also can be/is used to create several noises ("s", "r", "t", etc) when it passes the throath, tongue and teeths, which are added to the voice and also filtered. These variations, slower than the voice's pitch, are variations in the frequency-spectrum of our voice. If these spectrum-variations are extracted and used to parametrize the spectrum of a sound, similar to our voice, we get a synthesis of our voice. This synthesis will be as good as the spectrum-analisys and reapplication to the sound are. A well known example (at least for musicians) is the Jew's harp where the instrument creates the sound (voice) and the mouth does the vocalization. A Vocoder is composed of following main sections: The analisys section (FORMANT) that extracts the spectrum variations of the vocalization source (speech, drums, etc), the voice section (CARRIER) where these variations are applied to the target sound (strings, pulsewaves, noises etc), something to interconnect both sections (routing MATRIX) and other sections, for signal conditioning like GAIN, MIX, PAN and VU-Displays etc. The names in uppercase are those I used in Voxx. 3.1.- Formant section: The formant section is composed of 16 Band-Pass-Filters (BPF) for different frequencys (like an Equalizer) covering the desired frequency spectrum and Envelope Generators (EG's). Each BPF lets pass-through the part of the input signal's spectrum that lies around the BPF's center- frequency (Fc) attenuating the rest of the signal's spectrum proportionally to it's "distance" to The BPF's Fc. In other words this stage "slices" the Formant signal in frequency bands. The more bands (BPF's) a vocoder has the more precise is the spectrum characteristic it can analyze. Each band output ("slice") passes in the next stage to an envelope generator to form a envelope for each band, proportional to the formant signal's spectrum. As mentioned before, the vocalization is slow in relation to the sound, threfore envelopes are used instead of the direct BPF's output. The Attack/Decay time of The EG's is adjustable via the ENV-Faders to create different effects of vocalization. 3.2.- Carrier section: This section also has 16 BPF with the same Fc's as the formant section and again here the the carrier signal is filtered and "sliced" into spectrum components but this time the BPF's outputs go to Value-Controlled-Amplifiers (identical to synthesizer VCA's but controlled by digital Values, not Volts). The control value for these amplifiers is supplied by the Formant Envelopes. The result is that each Carrier-band output is modulated in amplitude by the amount of signal of this band in the Formant signal. If all results are added (MIXed) together the result is a "symbiosis" of the "speech" of the formant with the "voice" of the carrier. This is the principle that makes Talking Instruments talk! (or sing?) 3.3.- MATRIX: In the beginning I mentioned the military purpose of a Vocoder to code spoken messages and it was based on arrange the routing (Patching) of formant envelopes to the carrier in an unnatural order to make the speech/voice not understandable. Only with the reverse routing it would be possible to reconstruct partially the original speech. I do not know if this was usefull anytime for these purpose, but for musicians and the movie-FX-sections (Greetings from Robot-Worlds) I am sure it is . This routing is done in Voxx via the MATRIX an it is intended to route the formant envelopes to the carrier amplifiers. 3.4.- Additional sections (at least for Voxx): I/O-Section: This section is for input and output signal gain adjust and level display. SPECTRUM & settings section: This section displays the formant spectrum envelopes and allows some global settings for envelope modes. MIX/PAN section: The resulting signal is adjustable in this section via the MIX faders and the PAN knobs for each band similar to an equalizer. 4.- OPERATION: This long description (I hope, I have reached something more than confuse you) is followed now by the operation of Voxx. 4.1.- Connecting the Falcon030 : IMPORTANT! The Falcon030 audio inputs are designed for microphone signals and very sensitive. If you connect them with a LINE-Output of instruments, CD-players or other audio devices be carefull with the levels. In this case the better way is to insert 200K Resistors in series with the audio-source and the Falcon030 Inputs as in Fig. 1 to reduce Noise and Humm. For more information about this, contact ATARI Corp. or your local dealer. Fig. 1 ....................................................................... : : : Instrument Resistor Falcon030 Inputs : : : : Shielded Cable +------+ : : Line-Out-Left ==================| 200K |=============- Left : : +------+ : : : : Shielded Cable +------+ : : Line-Out-Right ==================| 200K |=============- Right : : +------+ : : : : : :.....................................................................: To connect the Falcon030 for use as Vocoder effect you need: FORMANT sound source like a MICROPHONE, Tape deck, musical instrument, etc, connected to the Left-Input of the Falcon030. CARRIER sound source like SYNTHESIZER, elctric guitar, etc connected to the Right-Input of the Falcon030. A headphone, amplifier etc, connected to the Falcon030 stereo output. NOTE: Uppercase devices are the most used in a Vocoder effect (see chapter 5.) 4.2.- Voxx-Screen: The following is a blockdiagramm of the Voxx Vocoder as it is arranged in the screen: ------------------------------------------------------------------------ "Desk" "File" Menu Bar ------------------------------------------------------------------------ I/O Section Spectrum & settings Matrix +------------+ +----------------------------+ +----------------------+ | #### #### | | ########################## | | F | | #### #### | | ########################## | | E | | #### #### | | ########################## | | D | | #### #### | | ########################## | | : | | #### #### | | ########################## | | : | | F C L R | | | | 2 | | O A O O | | P1 P2 P3 P4 P5 P6 P7 P8 | | 1 | | R R U U | | | | 0 | | M R T T | | FREEZE SLOW FAST STORE_PRG | | RST 0 1 2 .... D E F | +------------+ +----------------------------+ +----------------------+ +-------------------------------------------------------------+ +------+ | E | | Voxx | | N 16 ENV-Faders | | F | | V | | U | +-------------------------------------------------------------+ | T | +-------------------------------------------------------------+ | U | | PAN 16 PAN-Knobs | | R | +-------------------------------------------------------------+ | E | +-------------------------------------------------------------+ | | | M | | U | | I 16 MIX-Faders | | S | | X | | E | +-------------------------------------------------------------+ +------+ "#" = Displays 4.3.- Menu bar The menu bar is composed of the titles "Desk" and "File" 4.3.1.- "Desk" is the menu for the options: - About Voxx..: which shows the program's version and Users Registration. - The other options are the accesories your system has installed. 4.3.2.- "File" is the menu for Loading, Saving a file and Quit the program. *** - Load File: Loads a file with the settings for 8 user programs and the previous saved memory settings. *** - Save File: Saves a user file with the 8 user programs as well as the actual memory settings. NOTE: The file extensions are predefined as "VXD" (VoxX Data) - Quit: Exits the program. 4.4.- I/O Section The I/O section is composed of 2 VU-Displays for Input and Output levels, Left and Right each. The left input of the ATARI Falcon030 is for the FORMANT (speech) and the right input for the CARRIER (voice instrument). The output is the stereo effect (Left and Right). The 4 faders below are for adjustment of the input and output levels. To move a fader, point it with the mouse and press the left button, holding it (the arrow will change to a hand), now you can move the mouse up and down to adjust the selected level. The slider will follow within his limits while the left mouse button is pressed. 4.5.- Spectrum and settings section The large display, shows the actual envelope value for each CARRIER-band that is extracted from the Formant source, like a spectrum analyzer. The frequncy for each band is displayed below. The program buttons allow the selection of 8 user setting programs that are loaded at the start of the program or via the "Load File" option in the Menu title "File". These are user programs. Each of these programs holds the settings for all adjustable parameters. Pressing a program button, the selected program is copied to the edit memory . Each change in the adjustements is done in the edit memory (those that are active). If you want to store these settings for future use you must write them to one of the 8 user programs (see STORE PRG) and then save them with he option "Save File" in the menu title "File". Of the 4 buttons at the bottom the 3 named FREEZE, ENV SLOW and ENV FAST are for a global range setting of the formant envelope attack/deacy velocity. FREEZE sets all attack/decay velocities to zero regardless of the ENV fader settings, freezing all actual envelope values until another button, SLOW or FAST is pressed. This function is usefull to equalize the CARRIER with a FORMANT's spectrum characteristic. SLOW and FAST set two different envelope velocity ranges with a relation 1 to 10. *** The STORE PRG button is to store the actual settings (in memory) in one of the 8 available programs. To store a program press STORE PRG, all the program buttons will then show pressed and then press the program button where you wish to save the settings. The settings will be recalled each time you press the selected program button. 4.6.- The MATRIX The matrix is used to connect the FORMANT Envelopes to the CARRIER amplifiers. For each band there is a FORMANT(source) button(green) and a CARRIER(target) button (yellow) labeled from 0 to F, where the 0 stands for the lowest frequency band and F for the highest. With this matrix it is possible to assign or route the envelope of one determinated frequency band to any of the CARRIER-band-amplifier. So you can assign a low frequency amount in the FORMANT to modulate a high frequency band of the CARRIER and vice versa. In a 1 to 1 routing the effect of a talking instrument is the most notable while the shifting of the bands in both directions by one or two (0 with 1, 1 with 2, ... E with F or vice versa) adds the effect of pitch shifting (which is the logical consequence of shifting the bands). Very scarammbled routings may result in interesant and unespected effects of vocalization that surely will not be understood as human speech, regardless of what source for the FORMANT is used. The RST button ReSTores the 1 to 1 routing of the MATRIX for comfort. To operate in the matrix is very simple, then once the mouse enters the routing field, it's pointer transforms in a cross that intersects with both the FORMANT and CARRIER band buttons. If you want to connect FORMANT band 5 to CARRIER band E place the cross in the position where the green button "5" and the yellow button "E" are pointed by the horizontal and the vertical lines respectively, then press the left mouse button and the routing will be done. You can do this routing as you like. A FORMANT source can be routed to one or more CARRIER targets but a CARRIER target can only recive one source. This means that if a source is routed to more than one target there will be one or more sources without a respective target. Leaving the routing field returns the mouse pointer to the usual arrow. 4.7.- ENV section This section consists of 16 faders each one assigned to a frequency band. According to the range selected with the ENV SLOW/FAST buttons it is possible to adjust the attack/decay for each FORMANT envelope. The lowest slider position is for slowest and the highest for fastest attack/decay times. These sliders are moved by pressing the left mouse button while it is positioned in one of the faders and keeping the button pressed moving the mouse up and down (pointer is now a hand). A speciality for this section as well as for the MIX section is that if you move the mouse pointer over another fader of this section while the button is pressed, then the new pointed fader becomes active leaving the one before in the last position. With this method it is possible to "draw" the slider positions with the mouse, moving it over the entire fader section. In this way it is possible to slide all faders down or up by entering in one fader, pressing the left mouse button and holding it, to travel the mouse pointer accross the entire screen. While the mouse button is pressed the only affected faders will be those of the section where the mouse pointer was in the moment the left button was pressed. 4.8.- PAN section Since the FORMANT (left input) and the CARRIER (right input) are used both to form one signal, this section is for adjusting the stereo panorama position for each modulated CARRIER band (result output), to create a stereo effect. It is provided with 16 knobs (potentiometer simulations), one for each band. To move one of these knobs move the mouse pointer to it and press the left mouse button and while holding it, move the pointer around the knob. While the left button is pressed the knob mark will point in the direction of the mouse pionter over the entire screen. 4.9.- MIX section The result of each coded band now is ready and with this section it is possible to adjust the gain for each band (equalize) to fit the desired tone characteristic. The MIX faders are adjusted in the same way as the ENV faders. Additional information: When any adjusting element is being changed (faders and knobs), each variation is inmediatly send to the DSP (and not when the left mouse button is released). You will hear the changes in realtime (as fast as realtime is possible). This has a disadvantage: The faders are a little slower than those that are commonly used to set parameters (here the information is actualized after the change/movement is completed by releasing the mouse button. I think that for a musical effect, realtime is a more important factor than fast slider animation. Recalling a program also involves sending all parameters to The DSP. 5.- Some Useful Hints Experience has shown that the use of a vocoder could be frustrating for some users due to bad understanding of it's operation and what the user wants to do with it. My shortest explanation of a vocoder I ever had given to those who asked me "what is a vocoder?", was: "it is like a good equalizer acting over a sound (CARRIER) whose gain controls are fastly moved by a device that extracts the movement information from the frequency spectrum of another sound or speech (FORMANT)." To obtain a good vocoder effect it is important to know what kind of effect is expected and what FORMANT and CARRIER sound sources are used. The most applications use speech as a source for the FORMANT and synthesizer-sounds for the CARRIER. The FORMANT sources like speech should be clear and cover the most part of the spectrum (use the display). A thin voice like through a phone or a smooth one (like mine) are very poor in the spectrum's "Skyline". A very good speech source is that of the News Speaker in the FM/UKW-Radio (They have all the equipment to fill the spectrum with speech). I hearthly recommend this test! If using your own voice try not to sing or vary the pitch according to the music (else your spectrum moves with or against the spectrum of the carrier creating unregular highs and lows in level). Remember that the most part of the voice (sound) of the FORMANT is discarded, depending on the envelope settings, and only the vocalization is extracted. Drums or other percussions are also used as formant to create rythmic vocalizations of an instrument. Here the limits and settings are unlimited and depend of your imagination. CARRIER sources should be rich in harmonics and these are all those clear and sharp sounds like Strings, Brass and all those sounds whose waveform is based on sawtooth and pulses. Square, triangle and sine waveform based sounds (smooth ones) like Flutes, Whistles and some organs aren't good ones. Their harmonics are very small in relation with the fundamental which will dominate the spectrum (a true sine has no harmonics) and the resulting sound will be only in the bands near the fundamental's frequency band. The CARRIER's pitch is the pitch for the resulting effect, here is where the melody, chords or whatever should be played. I will try to list the effects and the best settings as well as sources for each one: a) Talking (singing) instruments, Choirs, Backgrounds, Harmonization: FORMANT : Human Speech CARRIER : Strings, Brass, Sawtoths, Pulses playing the melody or accompainement chords. Settings: Envelope SLOW ENV Faders: upper positions MATRIX: 1 to 1 or shifted by one or two or Envelope FAST ENV Faders: lowest positions (in upper positions FORMANT's pitch adds to the result) b) Robots: FORMANT : Human Speech CARRIER : Strings, Brass, Pulses, Sawtoths, with constant pitch (no melody) or steady chords. Settings: Like a) c) Solist Singer FORMANT : Human Speech CARRIER : Strings, Brass, Pulses, Sawtoths, with monophonic (one Finger) melody (synthesizer options like DUAL, UNISON, FAT, PORTAMENTO etc have very good results) Settings: Like a) d) Rythmic Chords and sounds FORMANT : Drums, percussions CARRIER : Strings, Brass, Pulses, Sawtoths, etc. Settings: All Envelope settings (except FREEZE) e) Warm instrument contouring (variable filtering) FORMANT : No limits CARRIER : No limits Settings: All Envelope settings (except FREEZE) e) Equalizer (fixed filtering): FORMANT : Blows in the micrphone Noise or any sound CARRIER : No limits Settings: First envelope SLOW or FAST. When the spectrum display reaches a desired characteristic press FREEZE or using Noise or blowing the micro and pressing FREEZE when spectrum display is equally leveled. Use the MIX faders to equalize the sound. 6.- SPECIFICATIONS The following are the main Voxx specifications: Number of Bands : 16 FORMANT Filters and 16 CARRIER Filters Filter Types : Digital-IIR, 4-Pole Band-Pass Center Frequencys : 125, 160, 210, 275, 360, 460, 600, 780, 1020, 1325, 1725, 2250, 2900, 3800, 5000 and 6400 Hz. Sampling Rate : 20.77 kHz, 16 Bit Stereo DSP Usage : 100% Dimensions(Pixels): 630 x 460 x 1 Pixels (W x H x D) Memory Consumption: aprox. 512 kB 7.- AVAILABILITY of Voxx Version 1.00 Voxx will be available in it's version 1.00 in March 1994! Voxx will consist of a Diskette with the program, a printed user's manual similar to this one, in German or English. Support and Updating: I will try to support any problems that may appear in the use of Voxx only to registered users, and to Update this program. The Update prices for registered users will only be those for material + handling. In the Future: Depending on Voxx's acceptance I am planning to MIDIfy Voxx, and for experienced users, add a Filter Editor to change the, BPF parameters like Resonance and Center Frequency. Any written sugestions are welcome and if possible will be considered! Coming Next: Pterodaktilus The Synthesizer(s) for Falcon030 Problems and errors with the Demo-Version: As far as I have tested and know, this demo runs without any notable error. There may be some problem when starting Voxx: The Spectrum Display will overdrive, at the output may be only noise and any attempt to reduce the Levels will be without effect. Solution: Start again and/or Cold Reset (Set amplifier inputs and volume low!). I am trying to solve this problem. If any error or strange effect occur please let me know! I will try to fix it. I have programmed and use Voxx myself with my Falcon030, as it comes from factory, without changes, additions or hardware upgrades with TOS 4.02 and 4.04. Multitos and Voxx: I recommend to use Voxx in the normal TOS mode (Single Task). Due to the intense communication between Voxx and the DSP, I doubt if there is time enough left for "Multitosing". Prices will be: Germany: DM 195,- (+ Porto und Verpackung, z.Zt. nur V-Scheck) Rest of Europe: DM 195,- (+ Postage & Packaging, Eurocheque Only) Contact to: Hans Achim Mueller Nadlerstr. 6 D-69214 Eppelheim GERMANY Distributor inquiries are welcome! January, 1994