diff --git a/README.txt b/README.txt new file mode 100644 index 0000000..22b6a0a --- /dev/null +++ b/README.txt @@ -0,0 +1,141 @@ +/*-------------------------------------------------------------------------------- +* +* +* About MIDITONES +* +* +* MIDITONES converts a MIDI music file into a much simplified stream of commands, +* so that a version of the music can be played on a synthesizer having only +* tone generators without any volume or tone controls. +* +* Volume ("velocity") and instrument specifications in the MIDI files are discarded. +* All the tracks are prcoessed and merged into a single time-ordered stream of +* "note on", "note off", and "delay" commands. +* +* This was written for the "Playtune" Arduino library, which plays polyphonic music +* using up to 6 tone generators run by the timers on the processor. See the separate +* documentation for Playtune. But MIDITONES may prove useful for other tone +* generating systems. +* +* The output can be either a C-language source code fragment that initializes an +* array with the command bytestream, or a binary file with the bytestream itself. +* +* MIDITONES is written in standard ANSI C (plus strlcpy and strlcat functions), and +* is meant to be executed from the command line. There is no GUI interface. +* +* The MIDI file format is complicated, and this has not been tested on a very +* wide variety of file types. In particular, we have tested only format type "1", +* which seems to be what most of them are. Let me know if you find MIDI files +* that it won't digest and I'll see if I can fix it. + +* This has been tested only on a little-endian PC, but I think it should work on +* big-endian processors too. Note that the MIDI file format is inherently +* big-endian. +* +* +* ***** The command line ***** +* +* To convert a MIDI file called "chopin.mid" into a command bytestream, execute +* +* miditones chopin +* +* It will create a file in the same directory called "chopin.c" which contains +* the C-language statement to intiialize an array called "score" with the bytestream. +* +* +* The general form for command line execution is this: +* +* miditones [-p] [-lg] [-lp] [-s1] [-tn] [-b] [-cn] [-kn] +* +* The is the base name, without an extension, for the input and +* output files. It can contain directory path information, or not. +* +* The input file is the base name with the extension ".mid". The output filename(s) +* are the base name with ".c", ".bin", and/or ".log" extensions. +* +* +* The following command-line options can be specified: +* +* -p Only parse the MIDI file; don't generate an output file. +* Tracks are processed sequentially instead of being merged into chronological order. +* This is mostly useful when generating a log to debug MIDI file parsing problems. +* +* -lp Log input file parsing information to the .log file +* +* -lg Log output bytestream generation information to the .log file +* +* -sn Use bytestream generation strategy "n". +* Two strategies are currently implemented: +* 1: favor track 1 notes instead of all tracks equally +* 2: try to keep each track to its own tone generator +* +* -tn Generate the bytestream so that at most n tone generators are used. +* The default is 6 tone generators, and the maximum is 16. +* The program will report how many notes had to be discarded because there +* weren't enough tone generators. Note that for the Arduino Playtunes +* library, it's ok to have the bytestream use more tone genreators than +* exist on your processor because any extra notes will be ignored, although +* it does make the file bigger than necessary . Of course, too many ignored +* notes will make the music sound really strange! +* +* -b Generate a binary file with the name .bin, instead of a +* C-language source file with the name .c. +* +* -cn Only process the channel numbers whose bits are on in the number "n". +* For example, -c3 means "only process channels 0 and 1" +* +* -kn Change the musical key of the output by n chromatic notes. +* -k-12 goes one octave down, -k12 goes one octave up, etc. +* +* +* ***** The score bytestream ***** +* +* The generated bytestream is a series of commands that turn notes on and off, and +* start delays until the next note change. Here are the details, with numbers +* shown in hexadecimal. +* +* If the high-order bit of the byte is 1, then it is one of the following commands: +* +* 9t nn Start playing note nn on tone generator t. Generators are numbered +* starting with 0. The notes numbers are the MIDI numbers for the chromatic +* scale, with decimal 60 being Middle C, and decimal 69 being Middle A (440 Hz). +* +* 8t Stop playing the note on tone generator t. +* +* F0 End of score: stop playing. +* +* E0 End of score: start playing again from the beginning. +* (Shown for completeness; MIDITONES won't generate this.) +* +* If the high-order bit of the byte is 0, it is a command to delay for a while until +* the next note change.. The other 7 bits and the 8 bits of the following byte are +* interpreted as a 15-bit big-endian integer that is the number of milliseconds to +* wait before processing the next command. For example, +* +* 07 D0 +* +* would cause a delay of 0x07d0 = 2000 decimal millisconds, or 2 seconds. Any tones +* that were playing before the delay command will continue to play. +* +* +* Len Shustek, 4 Feb 2011 +* +*----------------------------------------------------------------------------------*/ + +Update on 28 Feb 2011: I fixed a bug that caused it to stop some notes too soon. + +I also wrote a "MIDITONES_SCROLL" program that displays a miditones bytestream as a time-ordered scroll, sort of like a piano roll but with non-uniform time.This is primarily useful to debug programming errors that cause some MIDI scripts to sound strange. It reads the .bin file created from a .mid file by MIDITONES using the -b option. + +Update on 25 Apr 2011: Scott Stickeler pointed out that it doesn't work if compiled for a 64-bit environment. I'll put fixing that on my to-do list, but in the meantime the workaround is just to compile for 32 bits. (Thanks, Scott.) + +Update on 20 Nov 2011, V1.4: Added options to mask which channels (tracks) to process, and to change key by any chromatic distance. These are in support of music-playing on my Tesla Coil. + +Update on 25 Aug 2013, V1.6: I finally fixed it to compile in 64-bit environments. I didn't have a way to test that, so thanks to David Azar for doing so. + +Update on 30 Dec 2013: I added version 1.1 of MINITONES_SCROLL with a "-c" option to create annotated C source code initialization of the music bytestream. This makes it easier to manually edit the bytestream. See the beginning of the MINITONES_SCROLL source code for more details. + +Update on 7 Mar 2013: I compiled 32-bit versions for people running Windows XP and Vista. Unfortunately code.google.com no longer allows downloaded files! So I put them in a Google Drive folder here: +https://drive.google.com/folderview?id=0B1ZOnb_w5lfBQkNPeFpvRHdQNnc + +Update on 5 April 2015: Now code.google.org is going away, so I've migrated this to github. +