Re: Ritardandi and Accelerandi for MIDI

[Michael Welsh Duggan]

Han-Wen Nienhuys <address@hidden> writes:

> Michael Welsh Duggan wrote:
>> Desiring to have my midi outputs support gradual tempo changes, I
>> hacked up the following file, which I present for discussion.  I would
>> be especially grateful for suggestions on how to improve this code, as
>> my scheme knowledge is sparse (I am much more conversant with elisp),
>> and my understanding of many of the lilypond internals is shaky, at
>> best.
>> 
>
> it's a nice hack, but I think it would be better to solve this at the 
> Performer level. You could look at how Dynamic_performer does crescendi 
> for inspiration.

I just looked at span-dynamic-performer.cc to see how it works.  If I
understand this correctly, it will announce a new Audio_dynamic item
after the start of a dynamic-span for each moment in which an event
occurs.  Is this correct?

My only problem with this is the following:  It doesn't appear to
allow a crescendo to happen throught a single note without some extra
hackery added.  It would be better (IMHO) if we could emit
Audio_dynamic events (or Audio_tempo events) at discrete quantum
intervals.  It doesn't seem possible, however, to emit Audio_items at
any moments other than those defined in the Music proper.
Suggestions?  Maybe Audio_staff::audio_items_ can be a priority queue
(by moment), allowing us to emit events out of order?

-- 
Michael Welsh Duggan
(address@hidden)