[2001/11/10]                                                [MIDI series]


                     *** RPG MAKER 2000 TUTORIAL ***

               HOW TO LOOP MIDI FILES AT A CUSTOM POSITION



                 by BadSector <badsect@sdf.lonestar.org>
                               ŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻ




   I once wanted to use premade MIDIs like those on vgmusic.com, or
 eventually compose my own soundrack. I imported a midi version of the
 Final Fantasy 2 battle theme which in the original game starts by an 
 intro, and then the rest of the tune loops until the battle finishes.
 The MIDI standard does not include such a feature, because it was meant
 for simple communication between musical instruments and computers, not
 to serve as a video game soundtrack. Due to the lack of technical
 information about the way RM2K interprets media and resource files, I
 tried to figure out myself. Here's what I found.


   MIDI uses special events named controllers in order to add special
 effects such as portamento, volume, modulator wheel, et caetera. These
 are stocked in the MIDI file the same way as note events. ASCII only
 chose an unused event (111) for the loopback position. When the music
 is finished, instead of looping at the beginning of the song, it takes
 you back to the place it saw the 111 controller before. Every original
 ASCII RTP midi files have this controller at the looping position, 
 track 1, channel 1.


   Now how to add an 111 controller? Many MIDI editors have a raw MIDI 
 code viewer utility which show every codes used in the MIDI file,
 its position, its track, its MIDI channel, et caetera. The editor I
 use is CakeWalk SONAR. The operations I will describe are for this 
 software. You can get the 30-day trial version at this URL :

                    http://www.cakewalk.com/download/
                    ŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻ

 *** VERY IMPORTANT! make a backup of the MIDI file you are trying to 
     alter. If you find your tune all screwed up, don't blame me! :-P


   First, start SONAR and close the sample project window that appears.
 Open the midi file (in the File menu) and look at the track manager 
 (the one that just popped up when you opened the midi file.) Play the
 song (spacebar) and note the measure number (above the tracks) where
 you want to loop your tune. Positions in midi are counted as MBT, or
 Measure Beat Tick. Measures are generally made of 4 beats, which beat
 is made of 100 ticks. Generally you'll want loop at the beginning of a
 measure so just know the measure in question. 


   Select "Series of controllers" from the Insert menu. There, select
 the "Controller" radio button, The Number is 111, the MIDI channel is
 1,  the Value Range is 0 in the "begin" field and 0 in the End field
 also. Both time ranges are "X:01:000", where X is the measure where you
 want the music to loop. For example, if your song has to return to
 measure 3 when finished, just enter in the two fields "3:01:000". Now
 click OK, and save the tune! That's all! The music won't loop when you
 play it in SONAR or any MIDI player, but try it in RM2K! ;-)


   If you want to make it loop at another place than the beginning of a
 measure, then you'll need to be more attentive to the song's timing,
 because every tune has different timing rules. But these cases are
 pretty rare!


   One problem remaining. Some MIDI files use a lot of controls in their
 conception. As RPG Maker 2000 only move the position of the MIDI engine
 while doing loops (and even while switching between songs,) it happens
 that controllers such as volume and pitch bend remains at the same
 value as it was before, which is not necessarily the same value as the
 song's default settings; it could have changed values during the MIDI
 playback, and as long as there are no event placed to set these
 controls to their original value, the notes played at the beginning of
 a tune could inherit the controller values of the previous note. If
 the folk who wrote the MIDI file didn't think about looping the song,
 he(she) did not matter about resetting the channels default controls
 at the beginning of the looping measure. Some default settings are in
 the track's original definition (left part of the tracks window), and
 some are at the early part of event changes. To see a list of every
 raw event happening during the playback of the MIDI sequence, press
 ALT+4 to open the event list window, and press T in that window to
 change between tracks. Anyway, that will be the purpose of my next MIDI
 technical tutorial. So just don't blame me if your song loops but the
 music is messed up after the loop! ;-P