[jmsl] MIDI File Transcriber Crashes

[jmsl at music.columbia.edu]

Hi Greg

I believe I have solved this problem. The MIDI files that you sent me 
offlist had some anomalous time signatures in them.  I've never seen 
this before, but a very few of the time signatures were negative (like 
-8/4 time). This crashed the transcriber that lays out the measures of 
the score from the time signatures in the MIDI file.  It would not throw 
off midi playback devices that simply read note events.

MIDIFileToMusicShape now takes the absolute value of the time signature 
events in a midi file to safeguard against this.  Both your MIDI files 
import in a flash now, with no trouble. I just ran your code on both 
your midi files and they produce nice Lilypond output.  Note that there 
are some time signatures in there that do not seem very typical of 
Mozart or Handel, like 1/4, 15/4, and 13/4. JMSL does not guess at these 
time sigantures; they are specified in the MIDI file. But that's not a 
JMSL issue, and in any case I don't object to these time signatures!

When you wrote that shortening the MIDI files seemed to solve the 
problem, it was a bit of a red herring. It was not the size that was the 
problem (ie running out of memory or something similar), but you met 
with success when you happened to truncate the midi file before the 
negative time signatures occurred.

You can download a pre-release that includes this bug fix at 
http://www.algomusic.com/prerelease/

This pre-release also includes a bug fix that Georg Hajdu alerted me to, 
related to exporting MIDI files from Score (chord intervals with midi 
style velocities were not getting written properly)

Thanks
Nick Didkovsky



jmsl at music.columbia.edu wrote:
> Hi Nick,
>
> We've spent several days trying to nail down the root cause of the
> trouble.  The Score transcriber appears to crash with larger MIDI files
> that contain more than 1600 (or so) discrete events.
>
> I've attached a couple of examples that should allow you to reproduce
> the issue.  (We've been able to successfully pass these through by
> shortening them considerably...)
>
> Thanks for the much needed assistance,
> Greg
>
>
> jmsl at music.columbia.edu wrote:
>   
>> Hello Greg
>>
>> I tried your code with a MIDI file I happened to have on my system and
>> it ran OK.
>> So there must be something in the MIDI file you are using that is
>> revealing a bug that I cannot reproduce.
>> I would be happy to inspect your MIDI file and see if I can track down
>> what's causing the problem with JMSL's transcriber
>>
>> Thanks
>> Nick Didkovsky
>>
>> jmsl at music.columbia.edu wrote:
>>     
>>> Hi all,
>>>
>>> I'm getting the following error (attached) when attempting to transcribe
>>> a MIDI file with the code in the attached sample.
>>>
>>> Any ideas as to what is going wrong?  What other information would be
>>> helpful in tracking this down?
>>>
>>> TIA,
>>> Greg
>>>
>>>  
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