MIDICraft's MIDINET CD-ROM/MIDICraft's MIDINET CD-ROM.iso/CONVERTR/PTMID3.DOC

Text File | 1994-07-18 | 17KB | 351 lines

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
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