Re: [Denemo-devel] importmidi.c

[Richard Shann]

On Mon, 2009-08-24 at 13:09 -0500, Jeremiah Benham wrote:
> On Sat, Aug 22, 2009 at 02:32:18PM +0100, Richard Shann wrote:
> > In the course of removing compiler warnings I noticed that importmidi.c
> > was seriously abusing pointers. I have redefined the offending
> > structures to contain integers, and changed the code to suit.
> > I may have broken something in the process, I have just done a single
> > MIDI import to make sure that there is nothing completely stupid there.
> > But I thought that this would be a good time to get this cleaned up, as
> > we are at the start of the 0.8.10 cycle, giving us time to sort out
> > bugs.
> 
> Something is now broken.
Can you establish a test.midi file that shows a problem. Then revert the
changes to importmidi.c (they don't have any impact elsewhere) and see
if there really is a change?
I say this because it may give a clue to other problems that may be
there. The changes I made would not break the code unless it was already
using some undefined behavior (e.g. there was a comparison between a
pointer and an integer, which might do something strange on 64-bit
pointers).


>  I think I am going to rewrite some of importmidi.c and put it in scheme.

Of course, if you *were* going to do something radical like this, then
exploring problems in the current importmidi.c would be less attractive.
But my instinct tells me that this is not a good way to go. I have had a
look at the code, and I think it may well be close to doing what you
want.
Before committing to a big change in direction, I think it would be good
to get a test file that exhibits a problem, and let me look at what the
problem is. One thing that may be causing difficulties is that libsmf
has not been tested by us for doing what you are using it for: you might
change to scheme and find yourself with the very same underling problem.

Do you have a program that displays the contents of a midi file (did you
say libsmf came with something to display its own interpretation of a
file?)
Richard



>  importmidi.c is doing some ugly low level stuff and I don't feel that it 
> needs to be that way. My idea was to use libsmf to read the midi file and 
> dump the track data out to be processed via scheme. The c portion of this is 
> mostly all written in libsmf/smfsh.c. What is passed to scheme would be 
> similar to the output of smfsh utiltily included in libsmf/ . Then when 
> scheme recieves the string of events it then decides what to do about it. 
> 
> Some helper scripts that will need to be written to:
> 
> 1. determine how much time is left in the measure. 
> 2. if note is inserted and note duration > space left in measure tie the note 
> over to contain (duration - time_left) in next measure
> 3. if inserting a note at time x duration x does it collide with note already 
> inserted
> 4. if note collides and duration and start time are =, add the note to the 
> notelist for that object
> 5. if note collides and duration or start !=, put the note in next voice -> 
> (create if nonexistant) (if existant rerun check for collision)
> 
> Richard if you think this is not a bad idea then I will get started on this 
> now. I may need your help on some of it. 
> 
> Should I write a wiki page on my idea?
> 
> Jeremiah
> 
>  
> 
> 
> > 
> > I have also given the prototype of the DenemoDirective->graphic field as
> > GObject *, to reflect its evolving role as a graphical object
> > representing the directive. The case I have in mind is the textual
> > commentry that people may want to add to a denemo music file, which will
> > have its text editor stored here.
> > 
> > Richard
> > 
> > 
> > 
> > 
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