130 MIDI Tool Box

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Text File | 1993-04-13 | 18KB | 326 lines

MIDIMOD - Amiga Noise/Sound/Protracker to MIDI file converter (c)opyright Andrew Scott 1993 MIDIMOD - What it does ---------------------- MIDIMOD is a program which converts music modules generated by Amiga tracker programs (MOD files) to general MIDI format 1 (MID files). It is menu- driven and if not "user-friendly", at least "user-polite". No temporary files are created at any stage, so it is ok to be run on a floppy (though a disk-cache utility or a fast drive are preferred). Some editting of the output MID file will probably be necessary, but only to normalise volumes. Why convert MOD files to MID files? ----------------------------------- Even though MOD files contain some music-instructions that cannot be represented in MID format, there are many reasons why it is desirable to have music in MID form rather than MOD form: * Some sound cards cannot play MOD files, only MID files (eg. Ad Lib) * Top-of-the-range music editting programs do not handle MOD files, but almost always handle MID files * There exist programs to print out MID files as musical score. I don't know of any which do the same for MOD files * MID files tend to be much smaller than MOD files * On some sound cards, MID files sound better than MOD files (although on many others the converse is true) * MID files are more portable, having a well-known format, and have utilities on many different computers. MID files _ARE_ the industry standard. * MID files can be played on professional keyboards, allowing expert recording/presentation of music * Umm.. Microsoft Windows comes with a MID player but not a MOD player, so you can play MID files as a background task (and insert MID files into documents etc. etc.) Ok.. have I sold you on MOD->MID conversion yet? How to use MIDIMOD ------------------ After starting up MIDIMOD (I assume you know how to do that), you can select menus and commands by simply pressing a key. There are 3 menus: * File menu (press "F"): commands to do with files * Samples menu (press "S"): commands to do with samples * Help menu (press "H"): commands to do with help You can also use the cursor keys to select menus and commands, and then press <RETURN> to select that command. The File Menu ------------- The file menu consists of 4 commands: * Destination MIDI file (press "D"): A dialogue box will appear and ask you to enter the name of a MID file. After entering the full name (including extension eg. TECHNO.MID) press <RETURN>. If the file you entered already exists then you will be asked if it can be overwritten.. press "Y" for yes or "N" for no. * Source MOD file (press "S"): A dialogue box will appear similar to the "Destination MIDI" one. Enter a filename then press <RETURN> * Convert (press "C"): This will convert the MOD file you entered to the MID file you entered. I suggest before you do this step, use the Sample menu to set samples to appropriate instruments. Sometimes conversion takes a while - please be patient. If you get an error message which says that you have too many different instruments, then use the "Map samples" command to reduce the number. * Quit (press "Q"): Yep.. you quit MIDIMOD if you choose this command. The Samples Menu --------------- The samples menu consists of 2 commands: * Map samples (press "M"): There are many, many MOD samples on computers around the world, so it is impossible to automatically know which instrument is equivalent to which sample. You must tell MIDIMOD which instrument to use. Use the cursor keys and <RETURN> to select a sample from the list that appears on the screen. It is possible that the list will be longer than the screen and so you will need to move off the bottom of the list (don't worry.. the list will scroll upwards if it can). If you can't move off the top/bottom of the list, you will hear a beep. Each sample may have an asterisk "*" before it - this means that there is actual sample data that corresponds to this sample - ignore any other samples.. they won't be converted (except in name only). Each sample will have an instrument code to its right. If the code is prefixed by a "D" then it is a percussion code. Anyway.. after selecting a sample, a list of all of the available instruments will appear on the screen (it is another scrolling menu). Select one and the appropriate code will appear to the right of it. If you don't want to select anything from a menu, just press <ESCAPE>. So when all samples have been given instruments (sometimes they will already have an instrument code.. it is best to leave these codes as they already have been matched with a sample's name) press <ESCAPE> * Transposing (press "T"): Even if you have matched a MOD sample with a MIDI instrument there is no guarantee that each will play at the same pitch. MOD samples tend to sound high, low, very low, or slightly off pitch when both MOD and MIDI instruments play the same note. The trick is to map MOD samples to a different note during the conversion, so that there won't be any horrible musical clashes. A good way to do this is to find a sample that maps exactly to a MIDI instrument, and then get a MOD-editor and play other samples, and compare those samples to the "true" sample. This way you can find the number of semitones difference there are between a MOD sample and its instrument equivalent. For example, bass guitar samples are usually an octave lower (sometimes two) than their actual note. As an octave is 12 semitones, if the guitar sample is transposed down 12 semitones, it sounds ok. Another example, chords are usually made up of 3 notes which are played simulateously (major chords have part of them transposed up 4 semitones, and another part 7 semitones where minor chords have 3 and 7 semitone transposed parts). After selecting a MOD-sample from the menu (the numbers on the right are the transpose values), you can enter in its transposition. For a bass sample you might enter: -12 then press <RETURN>, whereas for a major chord you might enter 0, 4, 7 then press <RETURN>, and for a bass major chord you might enter -12, -8, -5 then press <RETURN> (note than -12+4=-8 etc.). During conversion, these transpositions are applied and hopefully the MID-file won't sound as if many musicians are playing using different scales. A couple of things you need to watch out for: if one of the transposition values is 0 then it must be the first value, also don't transpose percussion instruments - it's not a good idea. * Save info (press "S"): Because it is nicer to have the computer select instruments and transpositions for you than having to look them up each time, MIDIMOD keeps a list of "known" mappings/transposes from MOD-samples to MID-instruments. Once you have selected a mapping using the "Map samples" command or a transposition using "Transposing", you can use this command to save a sample's info to the info file. Just select the sample with the cursor keys and <RETURN> and it is done. Press <ESCAPE> to leave this command. The Help Menu ------------- There is only 1 command in the help menu: * About (press "A"): This displays some information about MIDIMOD. Press any key to make it go away. If you really wanted help.. print out this document and use it as a reference while you use MIDIMOD. If you are still stuck, call up a friend who knows a bit about computers and ask them what to do (but you were going to do that anyway weren't you?).. it may help if they know something about music too. Maybe get in contact with a hacker-friend and a muso-friend. On the other hand, maybe it would be best to throw a party and invite all your friends around. Command Line Parameters ----------------------- When executing MIDIMOD, you can put the two filenames on the command-line eg. midimod headbang.mod techno.mid The first filename (you guessed it) is the MOD file, and the second is the MID file. If the MID-file already exists, then you will be asked if you really want to overwrite it. Example Session --------------- Ok.. just incase everything I have said so far has gone over your head, here is the way that I use the program (and it works for me.. honest!): * Run MIDIMOD by typing "MIDIMOD" at the command-line and press <RETURN> * Press "F" followed by "S" to choose the "Source MOD file" command. * Enter the MOD file name (eg. headbang.mod) and press <RETURN> * Press "D" to choose the "Destination MIDI file" command. * Enter the MID file name (eg. techno.mid) and press <RETURN> * Press either: the right cursor key, or <ESCAPE> followed by "S" Then press "M" to choose the "Map Samples" command. --1-- * Now use the up cursor key and the down cursor key to highlight a sample, then press <RETURN> to select it. Remember, only the samples with a "*" on the left-hand side are actually samples, the rest are probably just advertising. * Now use the up cursor key and the down cursor key to highlight an instrument (you should be getting quite good at this now) then press <RETURN> to select it. If the sample was percussion, you should've selected a percussion instrument (the ones with a "D" on the left). * Go back to --1-- and do these steps until you get sick of them, or all of the proper samples have been allocated an instrument * Press <ESCAPE> to quit from this command * Press either: the left cursor key, or <ESCAPE> followed by "F" Then press "C" to choose the "Convert" command. * Wait for the disk to stop writing, and the cursor to reappear. * Press "Q" to choose the "Quit" command. There should now be a file lying around called "techno.mid" or whatever you typed in. This is the MIDI equivalent to the MOD file. The Instruments --------------- The list of MIDI instruments is kept in the text file "midimod.ins". Each instrument separate line. The first 128 lines must hold the instruments 0 to 127. The lines after this hold the percussion instruments (no more than 128). All instruments should have a code as the first thing on the line. The code must consist of the letter "D" (only if it is a percussion instrument) followed by a number from 0 to 127. This file can be editted with a text editor to put in the instruments for your particular soundcard/ computer/keyboard/software etc. The supplied instrument file contains the Soundblaster MIDI patches, if you are using a synth or a different sound card, then edit this file and insert the correct instruments for you. The Info File ------------- A list of default mappings and transpositions is kept in the text file "midimod.map". This is maintained with the "Save info" command in the "Samples" menu, but it can also be editted with a text-editor. Each sample is on a separate line, and consists of the first word in the sample's name followed by 4 numbers, all separated by spaces. The first word in the sample's name comes right after any header (st-xx: or leading spaces) and terminates at the first space. The first number is a mapping number, the remaining three numbers are transposition values (normally 0 0 0). The mapping numbers range from 0 to 255. The numbers 0-127 correspond to the MIDI instruments 0-127, and the other mapping numbers are the percussion instrument codes plus 128 (without the "D" infront). The transposition values hold either a set amount to transpose the instrument by (first transposition value) or a mapping to a chord (two or more non-zero numbers). Any 0 transposition value must occur in the first position. Each line in the info file is in alphabetical order, and it would be a bad idea to put a sample in the wrong place. All of the mapping/transpositions in the supplied "midimod.map" file are for the soundblaster card (preferrably running windows). If none of the info applies to you, you can delete the file and replacing it with the "blank.map" file provided. It is probably better to note down some of the info in the given "midimod.map", as even if mappings are wrong, transpose values will still apply. What is this .mm file? ---------------------- Because there are some times when you don't want to store information about a MOD file in the info file, a file with the same name as the MOD-file except with a .mm extension is created. This .mm file holds all of the information that you have entered about the MOD-file. It is automatically read in when you load the MOD file, and automatically saved when you quit. It is read in just before checking the info file (above), and so if you have added any new sample info that applies to that particular MOD-file it will be included. You can safely delete the .mm file, but it will come back next time you using that MOD-file. Notes on Conversion ------------------- Firstly, the way the algorithm works, each different instrument is allocated a different channel (this makes later editting of the MID file _MUCH_ easier). As there are only 16 different channels this causes a bit of a problem when you have a MOD file with 31 different samples. All is not lost due to the nature of MOD files. Each percussion instrument can be put on the same channel (10), giving you unlimited percussion instruments but 15 channels for the other instruments. If the MOD file you are using has more than 15 completely different non-percussion samples then it is an unusual MOD file indeed. There is also some ambiguity with regard to multiple notes of the same pitch on the same channel in the MIDI format. The MOD format can handle it if the notes are on different channels, but if they are the same sample then MIDIMOD will map them to the same channel in MIDI format. Some MIDI players allow "overlapping" notes, some don't - I was going to automatically remove "overlapped" notes, but no MIDI-player that I have chucks a fit if they are in, so they are still there. Cross your fingers and everything should sound fine. You will almost definitely need to edit the resulting MID file, as such things as volume are very dependant on hardware and software. Also, some samples may not be recognised by MIDIMOD and may need transposing otherwise the tune might sound horrible.. but as soon as you find correct transpose details, feed them back into MIDIMOD so it can recognise them next time. Not all MOD effects can be reproduced in a MID file. Things that I have been able to reproduce include: * Tempo (given that your MID player can handle a tempo-track) * Note length (calculated from frequency, tempo, and # bytes in sample) * Pattern Break * Position Jump (well.. not really.. pretend its Pattern Break) * Set Volume * Note slides (slide up, slide down, slide to, fine-up, fine-down) all implemented, but permanently in glissando mode. * Arpeggio * Volume Slides (and finevolume slides), but only if they occur at the start of a note * Set Sample Offset (actually retriggers the sample) * Retrigger sample * Cut sample * Delay sample * Pattern delay Effects that I have not been able to reproduce, or have ignored on the grounds that they are silly in a MID file are: * Vibrato and Tremolo (not really possible to do nicely in a MID file) * Position Jump (I have sort-of included it) * Pattern Loop (dangerous.. can cause infinite loops.. MIDI doesn't support loops so left it out) * Set filter (an Amiga-only hardware effect) * Set glissando (permanently on) * Set vibrato/tremolo waveforms (no MIDI equivalent) * Invert loop (*sigh* MIDI can't even come close to implementing this one) Hmm.. looking back at what I have included, it seems that MIDIMOD has more features than some mod-file players I have seen! Source Code ----------- I am distributing the source code - in fact, so must you! If MIDIMOD is placed on a publicly accessible medium (eg. BBS, FTP-site, Shareware vendor), then the source code must be there too. It must always be possible for the user to be able to modify this program. This allows multiple-platform distribution, allows everyone to add their little tweaks or use their favourite optimiser, and is even educational (if you can stand my code). It is legal to only possess the executable-code, but not to distribute only the executable. It is legal to distribute only the source code. For more information on the license, see the textfile also distributed with this package. Oh.. by the way.. if your computer crashes when running this program and you lose 3 years of hard work and gain white hair, don't blame me.. blame the power station, or the computer store, or your nextdoor neighbor. Details of who not to blame are also in the license. The source code consists of two .c files and and two header files: * midimod.c - main program * midimod.h - header file for midimod.c * textwin.c - text-windowing system I notched up because I didn't have one, and because I wanted one for midimod. Hence it's rather incomplete. * textwin.h - header file for textwin.c If you are creating an executable, make sure you link textwin with midimod. MIDIMOD was compiled on Turbo C 2.0, though it should work on any ANSI C compiler.. ignoring the IBM dependant console stuff of course. How to get in touch ------------------- You can email me on the internet at: ascott@tartarus.uwa.edu.au I did have a FIDO-net address.. but I have forgotten it.. oh well. Snail-mail me at: Andrew Scott 55 McCabe Street Mosman Park Western Australia, 6012 Be warned.. I only speak English. Well.. I speak other languages as well.. but not very good! (a joke.. a joke)