## rosegarden-user

 [Rosegarden-user] 33840 -> 024-02-08-00 From: Johan Vromans - 2008-06-12 09:35:52 ```Hi, I could not find in the docs the exact way Rosegarden represents a time delta as MMM-BB-XX-YY in the event editor. MMM is the measure. Each measure has nn * TICKS units, where nn is the numerator part of the time signature. BB is the beat within the measure. Each beat has TICKS units. XX seems to be the offset within the beat, in 16 steps (0 .. 15). YY ?? A micro-offset? It this correct? Any pointers to where this is documented? Thanks, Johan ```
 Re: [Rosegarden-user] 33840 -> 024-02-08-00 From: D. Michael McIntyre - 2008-06-12 13:28:10 ```On Thursday 12 June 2008, Johan Vromans wrote: > Any pointers to where this is documented? I never documented it because I don't really understand it myself. I just muddle along semi-randomly. Hopefully Chris can offer the real explanation. -- D. Michael McIntyre ```
 Re: [Rosegarden-user] 33840 -> 024-02-08-00 From: Chris Cannam - 2008-06-12 14:14:16 ```On Thu, Jun 12, 2008 at 2:27 PM, D. Michael McIntyre wrote: > On Thursday 12 June 2008, Johan Vromans wrote: >> Any pointers to where this is documented? > > I never documented it because I don't really understand it myself. I just > muddle along semi-randomly. > > Hopefully Chris can offer the real explanation. Oh no! The pressure is on! Will I be able to remember what it's all intended to mean? OK, these four values MMM-BB-XX-YY are referred to in the code as "bar", "beat", "fraction", and "remainder". "Bar" is the bar or measure number as you would expect. "Beat" is the count of beats within the bar. The total number of beats is defined by the time signature, although it is not always equal to the numerator of the time sig (e.g. in 6/8 it is 2). "Fraction" is the count of hemidemisemiquavers (sixty-fourth notes) within the beat. In 4/4 there are 16 of these per beat, but for other time signatures that will vary. "Remainder" is the count of "Rosegarden's basic note timing units" within the hemidemisemiquaver. The base timing unit is 1/960 of a crotchet (quarter note), so there are 60 of these for each increment of the fraction counter. So, it's bars; beats (according to time signature); 64th-notes; and then whatever finer timing Rosegarden may happen to have a record of. Chris ```
 Re: [Rosegarden-user] 33840 -> 024-02-08-00 From: Johan Vromans - 2008-06-12 19:21:33 ```"Chris Cannam" writes: > "Beat" is the count of beats within the bar. The total number of > beats is defined by the time signature, although it is not always > equal to the numerator of the time sig (e.g. in 6/8 it is 2). Just when I thought I understood... I create a piece in 6/8, and generate midi, this will have tick = 480 and 'time_signature', 0, 6, 3, 36, 8 Since it is 6/8, there are 2 beats per measure, so the number of ticks per measure is 2 * 480 = 960. This would give a time delta per 1/8 note of 160. However, each 1/8 note is generated with a delta of 240. So the number of ticks per measure appears to be 1440 instead. Apparently I'm overlooking something... > "Fraction" is the count of hemidemisemiquavers (sixty-fourth notes) > within the beat. In 4/4 there are 16 of these per beat, but for other > time signatures that will vary. In 6/8, this will be 24, right? -- Johan ```
 Re: [Rosegarden-user] 33840 -> 024-02-08-00 From: Chris Cannam - 2008-06-12 19:40:03 ```On Thu, Jun 12, 2008 at 8:21 PM, Johan Vromans wrote: > I create a piece in 6/8, and generate midi, this will have tick = 480 Ah, introducing MIDI export complicates the matter. The timebase used for MIDI export is different from the internal resolution. The original intention, I imagine, was to make the MIDI export timebase configurable, but as it happens it is currently hardcoded to 480 ppq -- only half the internal resolution. > Since it is 6/8, there are 2 beats per measure, so the number of ticks > per measure is 2 * 480 = 960. Again, this is not the same in MIDI export. MIDI timebase is always per quarter note, not per beat, and there are three quarter notes in a 6/8 bar, which is where your 1440 comes from. Rosegarden doesn't "think" in MIDI time (or MIDI anything much) internally. >> "Fraction" is the count of hemidemisemiquavers (sixty-fourth notes) >> within the beat. In 4/4 there are 16 of these per beat, but for other >> time signatures that will vary. > > In 6/8, this will be 24, right? Right -- as far as display in the event list (or transport window in musical time mode) is concerned. Chris ```
 Re: [Rosegarden-user] 33840 -> 024-02-08-00 From: - 2008-06-12 20:27:44 ```[Quoting Chris Cannam, on June 12 2008, 20:40, in "Re: [Rosegarden-user"] > The timebase used for MIDI export is different from the internal > resolution. This pretty much explains it... I now have a symbolic MIDI dumper program that shows Rosegarden compatible event times :-) . Thanks! -- Johan ```