Hi all,

I'm a new member of this forum and I still don't know all about its rules, so sorry if I'm breaking any of those rules. And sorry for my English!

With this message I would like to confirm that something I have found is not a bug or if so, how can I solve it.

I'm working on a midi program which uses the functions of midi.c. Everything is working but when I change a drum kit by another one, no change is done. In fact, the standard kit is always used, even if I set a different one from the beginnig. When I do the same for other tracks (the program is a kind of sequencer/composer) which are not using drum sounds, the sound changes as expected. I mean, if I'm using the sound 10 in channel 1 and I change the sound from 10 to 23 (for example) the change takes effect inmediately. But if I try to use a drum kit in the channel number 10 (the one for this kind of instruments, as the standard GM says), the drum kit never changes, it is always the standard kit. I have debugged everything and this is the only thing I think could be failing:

static void raw_program_change(int channel, int patch)
{
if (channel != 9) {
/* bank change #1 */
if (patch_table[patch].bank1 >= 0) {
midi_driver->raw_midi(0xB0+channel);
midi_driver->raw_midi(0);
midi_driver->raw_midi(patch_table[patch].bank1);
}
/* bank change #2 */
if (patch_table[patch].bank2 >= 0) {
midi_driver->raw_midi(0xB0+channel);
midi_driver->raw_midi(32);
midi_driver->raw_midi(patch_table[patch].bank2);
}
/* program change */
midi_driver->raw_midi(0xC0+channel);
midi_driver->raw_midi(patch_table[patch].prog);
/* update volume */
midi_driver->raw_midi(0xB0+channel);
midi_driver->raw_midi(7);
midi_driver->raw_midi(global_volume_fix(midi_channel[channel].volume-1));
}
}

As you can see, the first instruction checks the channel and the code is only executed when the channel is not 9. This is the channel used for drums (you are right, if you see the midi standard it says that channel 10 is the one for drums, but in the code, even in the Allegro code, the channels begin with 0, so the midi channel 10 corresponds with the internal code channel 9). By the standard GM specifications, if you don't set any drum kit, the standard one is used and I think that is what is happening here. Thus, my question is, why we are checking the channel? I think a program change (in other words, an instrument change) would should done always, with no dependance of the channel, but that explicit instruction checking the channel 9 must have an explanation. Does anyone know it?

Is there any way to modify this code to delete that instruction? I have tryed to do it and recompile Allegro, but the code executed is the old one and not my modified midi.c. I'm working with Code:Blocks and Mingw32 in Windows 7, Allegro version 4.2.2 but perhaps I have not recompile it in the right way. I have done it using a console window with administrator permisions and the following instructions:

fix.bat mingw32
mingw32-make
mingw32-make DEBUGMODE=1
mingw32-make install
mingw32-make install DEBUGMODE=1

But it seems like the sources from SRC folder (in that folder is the file midi.c) are not used... Any error from my side?

If you want to check what I say, I have attached a small midi file created by my program. If you play it with a player like winamp or windows media player you can see its drums are not the standard ones, in other words, it sounds as it should. But if you play the file using a player based on the function play_midi from midi.c (which is the function that uses the piece of code I have detailed above) you can hear the drums are the standard ones. Here is a simple code of a wav/midi player based on that midi.c function:

http://altair.lcc.uma.es/clases/laboratorio/curso200203/tutoriales/Sonidos.pdf

Thanks in advance. Any comment will be very appreciated.

Best regards,

Jose

Hi Ron,

I have checked the Allegro library and it is in the correct folder. I have also checked if the code has more places where the channel 9 is considered to do or not to do something and I have found more checks, but they are not related with this problem. In fact, I have change manually the values by debug in the piece of code I said yesterday and... wow! then the Allegro player sounds as it should, so I'm pretty sure the problem is only this function and the check against channel 9.

As you suggested, my last choice was to recompile again. I have done it using the "clear" instruction but then, when I recompile the process crashes and says that the file gdi.c has an error I have tried many times and in different computers with different OS (windows XP and win7) but the compilation always fails. It seems like the cleaning process has cleaned too many things...

Then I have uninstalled Codeblocks, Mingw and Allegro and reinstalled all again, but replacing the midi.c file with my own midi.c. Then, the compilation works right and everything seems to be ok. I have recompile my program, run and... I don't understand. Although I see my midi.c, if I execute it step by step by debug I see that the code which is being executed is not my midi.c, but the original midi.c. It is very rare to see how the process is executing blank lines where there is no code, but those lines were the old midi.c code. When the channel is 9, the process jumps directly to the end of the function, after executing a blank line which corresponds with the old code line: if (channel != 9) {

I'm getting crazy. Has anyone any idea? I don't know what more can I do.

Thank you very much, and specially thanks to Ron and Elias for trying to help me. I appreciate it a lot.

Just to be sure... You used clean and not clear, veryclean or distclean? If you used veryclean then you'll have to reinstall the library because that erases some specially generated files... Just be sure to backup any modified files first.

I can't be too sure of what's going on, but when you run the program it's probably using a version of the Allegro DLL that is somewhere else on your system... Like C:\Windows\System32 maybe?? So even if you re-compile the library it won't matter because it is still using the old DLL elsewhere on your hard drive.

Since you're using a modified version of the library, I think the best bet for you is to static link to the allegro library. Since the official 4.2.2 DLL doesn't have those modifications, this will prevent the use of the wrong DLL if you distribute your app later on...

mingw32-make STATICLINK=1
mingw32-make STATICLINK=1 DEBUGMODE=1
mingw32-make install STATICLINK=1
mingw32-make install STATICLINK=1 DEBUGMODE=1

This will build the liballeg_s.a and liballd_s.a libraries. All you should need to do is change your project to link with those instead and then add the ALLEGRO_STATICLINK to your compiler define section...

That should do it

All the information for static linking should be available in the file "Allegro\Docs\Build\mingw32.txt"

[edit] Arg... Thomas Fjellstrom!

If you go static, you need to link to a bunch of extra libraries manually. I don't personally remember the full list for windows. But someone else should, and should follow up with it.

You are my idols! Thank you very much. Ron, I have specified those libraries and now it works perfectly!! Any instrument change takes effect, even if I change the drum kit instrument. Now I have total control of the tracks of my autocomposer. That was the last step to complete the first prototype of my application so... I'm very happy! Thanks, thanks, thanks! I would have been not able to do it without your help. I'm very grateful to you.