C/C++ Users Group Library 1996 July

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NAME ptmid - Creates Protracker MOD files or Multitracker MTM files from General MIDI files (ver 0.3) SYNOPSIS ptmid [-cFile] [-dChannel] [-fFrac] [-q] [-s] infile[.mid] [outfile[.mod]] DESCRIPTION Ptmid will take either standard MIDI format 0 or format 1 files and convert them into various Tracker-type files. MIDI files are industry standard, but need some sort of sequencer to be played, as there can be near infinite simultaneous notes (though about 20 is a standard maximum). Protracker files are 4 channel (though 6, 8, and just about any other variety is supported) files, but have a bank of digitized instruments included, so reasonable quality sound is produced given limited hardware. Multitracker files are similar, and support upto 32 simultaneous notes. Both Protracker and Multitracker files are referred to as Tracker files in this document. The differences between MIDI (extension .mid) and Tracker (extension .mod or .mtm) formats are more than superficial, and a fair bit of information is needed to be able perform the conversion - most of this is held in the configuration file: ptmid.cfg The format of ptmid.cfg is fairly simple: Any line beginning with a hash (#) is ignored, other lines contain configuration info. The first word on a line (called a tag) specifies what sort of information (and sometimes only one word is needed), anything following this word is used as supplementary information and depends of the sort of option specified by the first word. One type of word needs a little explaining: pitch. A pitch, when used in the configuration file, is a character string in the format of: C2, C#2, D2, D#2, E2, F2, F#2, G2, G#2, A2, A#2, B2 (that was a whole octave beginning with middle C). Other octaves can be used in place of 2, eg. D#2, A-1, etc. Here are a list of the tags permissible in the configuration file: spath: The word following this tag is the name of the directory that any subsequent samples will be found in. It must end in a trailing slash, and be located in the file before any line using the tags: def, xx, or dxx. def, or xx (where xx is a number): These options supply information on what samples (digitized instruments) should be allocated to what MIDI instrument numbers. "def" is the default non-percussion instrument, and must always be specified. "xx" is a specific MIDI instrument. After the tag are the filenames of the samples that can be used to represent the instrument (if multiple filenames are used, then the one sampled closest to the desired pitch for a note is chosen from the list). If an allocation is not present for some particular instrument, then the default instrument is used instead. A shortcut is to put a quotes (") mark instead of a list of filenames. This tells Ptmid that that instrument is identical to the last one specified. dxx (where xx is a number): This is similar to the above tag, but applies to percussion samples. The first word following the tag is the filename of the sample to associate with the appropriate MIDI percussion instrument (only one filename can be used). If there is another word following this, it is the pitch to play the sample at when used in the Tracker file. There is no default sample for non-specified percussion instruments, as these are simply not played. sample: The information following this tag tells Ptmid crucial information about a sample. Samples can either be in .SMP format (this is the default, and corresponds to headerless, 8 bit signed data), .WAV format, or .VOC format. The first word following the tag is the filename of the sample which is to be defined (and must correspond exactly to the filename of this sample used elsewhere in the ptmid.cfg file). The next word is the pitch of the sample when it's played (at 8287 Hz for .SMP files, or the normal rate for .WAV or .VOC files). Optionally, it can then be followed by a loop-start offset and a loop- length (in that order), specified in words (1 word = 2 bytes). After a sample is played it will stop if no loop information is given, otherwise it will start looping at the loop-start address and continue for the length of the loop-length (looping continues indefinitely). A "sample" must be present for EVERY filename given in one of the above options (def, xx, or dxx). drumch: The percussion channel is assumed to be 10, but some MIDI devices assume it is elsewhere, and so Ptmid must know what channel it will be to perform a correct conversion. Following the tag name is a number which is the percussion channel. Common values are 10 and 16. fract: Ptmid quantizes (that is, groups notes to the closest note) MIDI files duration conversion, and so must know what the smallest type of note is. Following the tag name is a number (possibly with a suffix of "t") which represents a type of note - this is the quantize fraction. Valid fractions are of the form: 4, 4t, 8, 8t, 16, 16t, etc. where 4 means a quarter note (crotchet), 4t means a triplet, 8 means an eighth-note (quaver), 8t means quaver-triplets, etc. It usually can't hurt to give a smaller note (larger value), though it uses up more memory, but the critical part is knowing if a triplet note is needed. If not specified, the fraction is assumed to be 16. This option can be overridden with the similar option specified on the command line. modfmt: This tag chooses the type of Tracker file to produce. If the word following the tag name is "1", then Protracker .mod files are produced (this is the default). If the word is "2", then Multitracker .mtm files are produced. maxchan: Following this tag is a number representing the number of channels to have in the final Tracker file. It will default to 4, and can have values upto 32. If creating a Protracker file, putting values other than 4 may result in a .mod file that cannot be played by your Tracker program, although 6 and 8 are common too. extend: If this tag is present, then an extended range of notes is allowed during conversion. Usually there is a 3 octave range, but since MIDI allows a 9 octave range converted files can sound wrong. With an extended range, 5 octaves are supported, but you need special trackers for this (the tracker DMP is one example). The best solution for this problem is to use multiple samples, each of which is digitized an octave apart, and specify all of them for an instrument. rgmode: There are 3 things Ptmid can do if despite using "extend", a note is out-of-range. These things can be chosen by specifying a number following this tag: 0 - This rounds a note to the nearest pitch (the default) 1 - Drop the note altogether 2 - Transpose the note by octaves until it's in range Mode number 2 sounds the best, but it can generate melodies that don't sound like the original, and is not the default. nocopy: This tag will stop copyrighted MIDI files being converted if it is present. Since MIDI files support a copyright notice as part of their official format, I thought that this would be a good option for the fascist-minded. Options in the configuration file may be given in any order, and are all optional except for "def" and "sample". DMP is written by Otto Crons (no relation :). How Ptmid works. Well.. It goes through the following steps: 1) Read the configuration file and check each sample specified (this is necessary so as to extract the sample-frequency of samples in .WAV or .VOC format). 2) Read in the entire MIDI file (except effects such as pitch bend, mod wheel, etc.) into memory. 3) Scan the tune and allocate samples to each note, convert the volumes etc. 4) Write the tune to disk as a Tracker file. If there are more notes than channels at any particular time, it picks what it guesses to be shorter notes rather than longer notes. The reason behind this is that shorter notes allow more notes to come later, freeing up channels sooner.. okay, so it's not a very good reason, but it tends to sound better than simply dropping notes. I originally wanted to do "channel pruning" before the writing stage occurred, but yes I'm slack and wanted to get a working copy released. And now with ver 0.3, I have modified it extensively, and still can't be bothered. Anyway, this means there is a bit of inelegancy: samples may be allocated to notes, but those notes are pruned later on and are never played, leaving redundant samples. Other things I want to add are: compression (ie. identification of common patterns and re-using them), MIDI effects, volume decay of samples, and calculation of default volumes (at the mo they are just set to 64). OPTIONS cFile "File" is the filename of the configuration file. If not given will default to "ptmid.cfg". See above for format of the configuration file. dChannel "Channel" is a number from 1 to 16. This is the channel used for percussion instruments. See "drumch" option above. fFrac "Frac" is a quantize fraction. It can take values of the form: 4, 4t, 8, 8t, etc. See the "fract" option above, which this option overrides. q Enables quiet-mode. Only error messages are sent (to stderr). s Enables statistics-mode. Displays all kinds of funky information to the screen while performing the conversion. This will allow you to make good choices for what to set different options to. I better give a short description of what all of this information is.. "Ticks to quantize" is the amount of MIDI ticks that every note will be rounded to (it defaults to a 16th note). The amount of ticks representing a particular time-value will change from MIDI file to MIDI file. "Number of tracks" is the number of tracks in a (format 1) MIDI file. You will need this many files open plus one to read the MIDI file. "Maximum quantize error" is the biggest MIDI note length rounding error. By relating this to "Ticks to quantize" you get an idea of how much notes will be off-timing. "Number of times it occurred" is obvious. "Number of times quantize error > 2 occurred" helps you get some perspective for the previous item, and how accurate the conversion was overall. "Number of pitch conversions out of range" is how often a pitch was encountered that was beyond the playable range for a sample (use the "extend" option in ptmid.cfg to decrease these errors - if you haven't already). "Number of dropped notes" shows how often a note was cut while being written to the Tracker file. It should stay pretty constant for any particular tune (even if you vary the quantize fraction), but by adding more channels you will decrease it. EXAMPLES prompt> ptmid -s -f32t jazz3 jazztune ptmid ver 0.3: Converting 'jazz3.mid' to 'jazztune.mtm' Ticks to quantize: 16 Number of tracks: 11 Maximum quantize error: 8 Number of times it occurred: 145 Number of times quantize error > 2 occurred: 501 Analyzing.. Number of pitch conversions out of range: 0 Writing.. Number of dropped notes: 0 Writing 10 samples: .......... Done. prompt> ptmid test ptmid ver 0.3: Converting 'test.mid' to 'test.mod' Analyzing.. Writing.. Writing 2 samples: .. Done. DIAGNOSTICS The following errors terminate immediately and return an exit code of 1 (disclaimer: error messages may not exactly match those shown below). Cannot find config file: xxxx Either ptmid.cfg cannot be found (eg. not in current directory) or the file specified with the option -c has been incorrectly given. Error in config file: line xx Something is wrong with the config file on that line. Check the above formats for options. No default instrument defined in config file Make sure there is a "def" option in the config file. No sample definitions found in config file Likewise, make sure there is a "sample" option. Invalid quantize fraction - using default You have incorrectly specified the fraction in the -f option. Make sure it is of a similar form to: 4, 4t, 8, 8t, etc. Ptmid is going ahead, but using the value 16. Cannot access file: xxxx The MIDI file you have specified cannot be opened for reading. Not a legal MIDI file: xxxx There is something wrong with the MIDI file you have specified (like it isn't one), or there is a copyright notice in it and the NOCOPY option has been enabled (see above). Cannot create file: xxxx The Protracker file cannot be opened for writing. No more files can be opened While reading the MIDI file, Ptmid has run out of file handles (there should be at least 1 more than the number of tracks in the file), so if you can increase them, please do (see manual on how to do this). The official version of Ptmid supports upto 34 track MIDI files (which opens 38 files under MSDOS) and won't work on larger ones - this is a bug with Turbo C. Cannot allocate any more memory Nasty. Try recompiling the sources to use a bigger memory model, install more memory (probably make no difference), switch to a different operating system, or wait until other users leave. I have managed to convert MIDI files upto 80k in size under MSDOS. The follow errors do not terminate immediately, though may cause early termination, hence will return an exit code of 0. Warning -- Pattern limit xx reached. Aborting! Try using a smaller number of the quantize fraction. A Tracker file will be created anyway, so at least you will have something. HISTORY 0.1 Initial release. Spread far and wide, and a couple of people were quite impressed. 0.2 Increase of maximum number of open files from 15 to 35 (involved patching Turbo C 2.0). Statistics mode added. Never officially released. 0.3 Removed bug with MIDI Sysex events. Removed bug where odd (as apart from even) length .SMP files weren't processed properly. Percussion samples now played for 1/8th note (rather than the length in the MIDI file). .VOC and .WAV files now supported. Pitch value added to end of percussion allocations. Pitch value for percussion samples after "sample" tag now makes sense. Ditto (quote) abbreviation added to config file. "spath", "rgmode", "modfmt" and "maxchan" tags added to config file, while "ptchan", "patmax" and "formid" are removed. Tags for .mod files corresponding to channel sizes are: TDZ1, TDZ2, TDZ3, M!K!, 5CHN, 6CHN, 7CHN, 8CHN, 9CHN, 10CH, 11CH, 12CH, 13CH, 14CH, 15CH, 16CH, ... 32CH. Oh.. and MTM files now supported (he waits for applause?). Andrew Scott INTERNET:ascott@tartarus.uwa.edu.au