[JimKurth]

I've read Microsoft's article on MIDI files, and I also looked into programming resources (no source code) about the file type. I understand how to read them but I only have one question: How do you program this to be played for multiple tracks? Do you load the contents of the file into memory and just jump to location xxxx:xxxx to grab another track's info to be played simultaneously? That wouldn't be so bad with small files but larger complex 16-track MIDI files seem potential for problems.

From what I understand each track chunk extends from start to end of the file and then jumps to the next track chunk from start to end and so forth. I'm not understanding how to grab this data and send it to the sound device to retrieve incoming midi commands. Maybe I'm thinking in the wrong direction (usually am). If any one knows the concept of how to do this please share with me. Thanks.

James Kurth
james.kurth@hotmail.com

[XMark]

Which language are you programming in, and which library are you using for sound?

It sounds like you're trying to re-invent the wheel by programming your own MIDI loading and playing routine, which should not be necessary because there are many libraries available to handle the whole thing for you. For example, the Allegro library comes with midi loading and playing routines.
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Mark Hall
Abstract Productions
I PLAYS THE MUSIC THAT MAKES THE PEOPLES FALL DOWN!

[JimKurth]

Well, I guess you could say I'm trying to make my own routines. I'm doing it because I feel the best way to manipulate things and troubleshoot problems is if you write the code yourself. I am programming in QuickBASIC and I have looked at a MIDI load/playback program for Qbasic, however it only plays 1 track and doesn't account for ticks or duration. I'd use libraries but most people add in too much stuff and I only want to use routines that I will use and how to manipulate it. I've seen a C++ MIDI loading program and since I don't program in C++ (and as hard as I try to learn it, it always stumps me), I'm forced to write my own routines.

I do know the file structure and my first guess is to write a TSR or a program shell that runs simultaneously in the background that initializes the sound card, and sets up the MIDI, and then loops while the game is running, waiting for MIDI commands and/or sound samples. Then, in the game, make an array of 16 cells (1 per track) and have it store the starting byte of that track from the MIDI file. Next, prepare for durations with Track TIMERs and lastly, when the current timer has reached the track timer, send the next MIDI command to this background MIDI player.

Of course what I'm thinking about sounds very tough and complex and it is, especially since I'm using Qbasic and MASM. But anyway thanks for the post.

-Jim

[Nodtveidt]

There's always QMIDI... :)
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If you play a Microsoft CD backwards you can hear demonic voices. The scary part is that if you play it forwards it installs Windows. - wallace

[BDZ]

I've kind of been wanting to do the same thing as Jim Kurth here. Is there any other simple solution besides QMIDI?

[JimKurth]

BDZ,

I'm going to attempt to write a MIDI loader/player in Qbasic. I'll keep you informed of the progress. I'm not going to take forever on it. I'm sure reading the file won't be a problem. It's playback and keeping everything else running smoothly that is the problem. This will be a big challenge for me, but I'll try.

I've got a complete list of Interrupts/Ports and the Internet for resources on soundcard programming (Not going to write "You're soundcard isn't compatible with this program" routines. Just straight guts for general SoundBlaster soundcards)

[DeveloperX]

[JimKurth]

DeveloperX:

I appreciate your input and after thinking things through, I think I just may port this to C++ (somehow, I don't know yet) using MS-VC++ Express and Allegro. I can get some good speed with QB right now (without any ASM code) graphics wise and I think I'll stick with 320x200x32-bit cuz all my graphics are designed for it and I like that style. I do understand some C and I studied it but trying VC++ was completely different (felt like I was instructed to chop down a tree and I was given a fish for a saw). I found a nice C++ Game Programming site that teaches C++ and lessons on Allegro (where is that link...? Oh here: http://www.cppgameprogramming.com/cgi/nav.cgi?page=allegbasics) So, i'll check that out. I do have the guts in Qbasic and flowcharts for some other modules/engines on paper, so porting over wouldn't be hard (no need to start from scratch). I really need sound and music in my game though. It's too powerful to be left out (for any type of media). I'll quit the Qbasic MIDI quest. I did find out how to program the SB and send info to it, and I do have a site telling me the complete layout of a .MID file. Maybe now I can have flicker-free video clips (i was double-buffering a 4-frame walking motion but it went so fast that you saw the flickering problem I guess). I'll post up the file soon... somewhere with a demo of it and the base to create these video files in QB. Anyway, Thanks for the input. BTW, I have played Xenogears and thought the graphics were nice but I wasn't fond of the battle style (i'm just used to old turn-based FF-style cuz that's what I grew up with). Right now, I don't use tiles at all. Only pre-developed images for my towns/buildings/worlds/etc and an array-based movement map to determine where the player can move.

Another good option to moving to C++/Allegro is Joystick commands. I spent a week researching USB PnP codes to receive input from my current gamepad, but beats me how to get it done. All I know is the company and model memory address (xxxx:xxxx).

Well, gotta get to work on my demo cd. Applied for a sound position at TimeGate Studios in Houston and they want a demo cd from me. So, back to work on it. Anybody play their games and enjoy them? They made Kohan series and the FEAR expansion pack.

[DeveloperX]

I've got Allegro & C++ tutorials on my site as well
Please, check em out. :)

http://www.ccpssolutions.com/index.php?pageID=community/articles.php&c=C

and

http://www.ccpssolutions.com/agps/

Goodluck.
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