wildmidi_lib.c

WildMidi Midi Library and Player

/*
	wildmidi_lib.c

 	Midi Wavetable Processing library
 
 	Copyright (C)2001-2004 Chris Ison
 
	This library is free software; you can redistribute it and/or
	modify it under the terms of the GNU Lesser General Public
	License as published by the Free Software Foundation; either
	version 2.1 of the License, or (at your option) any later version.

	This library is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
	Lesser General Public License for more details.

	You should have received a copy of the GNU Lesser General Public
	License along with this library; if not, write to the Free Software
	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

	Email: [e-mail]
		 [e-mail]
 
 	$Id: wildmidi_lib.c,v 1.18 2004/01/28 05:45:09 wildcode Exp $

	========================================
	Changelog
	----------------------------------------
	Aug 3, 2003
		- changed kill envelope from 6th to 5th
		- changed data_length, loop_start, loop_end to 22:10 fixed point
		- added fractional position to loop_start and loop_end
		- added fake reverb
		
	Aug 4, 2003
		- added MIDI_EVENT_DEBUG to midi event functions
		- fixed hold release killing off notes that hadn't been turned off
		  by note off
		- sped up fake reverb by doing it outside the channel mixing loop
	
	Aug 5, 2003
		- removed note_table init from ParseNewMidi, entries are now fully reset 
		  in do_note_on
		- moved fast kill envelope setting to sample loading
		- removed envelopes from notes, use ones from sample instead
		- optimized do_amp_setup functions
		- do_control_volume, do_control_expression, do_channel_pressure,
		  changed from setting note_table[] to note[] for performance.
		- optimizations of sample conversion,
		
	Aug 6, 2003
		- removed changing sample volumes, the amp setting is now apart of 
		  the midi volume maths.
		- re-write conversion functions to make them more clearer and less bug prone
		
	Aug 7, 2003
		- fixed volume, expression and preasure changes effecting all notes.
	
	Aug 8, 2003
		- spead up midi processing by using an event index
		
	Aug 9, 2003
		- spead up sampling and mixing by using a seperate function depending on fixed
		  modes
		- fixed data lock where it would sleep reguardless of lock state
		- fixed memory leak ... oops, forgot a free
		- removed track data storge, isn't required by the core functions
		
	Aug 10, 2003
		- created error function and changed all error messages to use it
		- malloc, calloc, realloc audit ensuring all are error checked.
		- fixed potential reading beyond end of midi bug
		
	Aug 11, 2003
		- fixed expensive interpolation over-running the sample buffer
		- changed stereo option so that changing it worked right away
		
	Aug 14, 2003
		- optimizations for and to the frequency calc code
		- removal of wide stereo (it sucked anyway)

	Aug 15, 2003
		- fixed volume levels for panning when non-linear volumes are used
		- removed fake reberb, it sucked on better sound systems.
		
	Aug 17, 2003
		- fixed autoamp
		- added env_time#= and env_level#= to timiidty.cfg parser.
		- fixed bug where last event in the midi before the last eot would
		  have a large delta. This is a bug in the midi file itself.
		- fixed some midi's having no sound cause they don't supply patch information.
		  Now defaulting all channels to bank 0, patch 0.
	
	Aug 18, 2003
		- preload samples
		- optimized envelope checking and controler code
		- fixed bug where some samples have an envelope rate setting that doesn't 
		  actually mean anything .. ie: 0x00 0x40 0x80 0xC0
		- fixed amp bug where initial left/right levels were set to 0
		- added timidity's keep=[loop|env] support for drum patches, 
		  now ignores loops and env settings for drum patches unless keep=[loop|env]
		  is in the patch line in the config.
	
	Aug 21, 2003
		- float to fixed point math conversions.
		- frequency range locked to 100 steps between notes
		  NOTE:need to test slow pitchbends with this, fast ones are fine
		
	Aug 24, 2003
		- optimized sample conversions
		- optimized note handling and sample/envelope position checks	
	
	Aug 28, 2003
		- compile level optimizations
		  NOTE: gcc builtins used
		- numerous bug fixes
		
	Aug 30, 2003
		- fixed sample inc calculation bug
		- fixed panning volumes, now percieved volume of the sample is the same no matter
		  panning position.

`	Sep 2, 2003
		- made noteoff/hold behaviour match midi standard
		- added remove=sustain to patch line 
		- added all sound off controller
		- fixed all notes off to only effect notes that aren't being held
		- changed envelope behaviour so that only non-sustaned samples hit envelope 4 
		  while note is on.
		- Added all controllers off event
		

	Sep 4, 2003
		- added master sample data lock
		- improved performance of the resampling algo
		
	========================================
*/

#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <math.h>
#ifndef _WIN32
#include <pwd.h>
#endif
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#ifdef _WIN32
# include <windows.h>
#endif
#include "config.h"
#include "wildmidi_lib.h"

/*
 * =========================
 * Global Data and Data Structs
 * =========================
 */

int WM_Initialized = 0;
signed short int WM_MasterVolume = 948;
unsigned short int WM_SampleRate = 0;
unsigned short int WM_MixerOptions = 0;

char WM_Version[] = "WildMidi Processing Library " WILDMIDILIB_VERSION;

struct _lowpass {
	signed long int in[2];
	signed long int out[2];
};

struct _filter {
	signed long int *delay[4][2];
	unsigned long int delay_pos[4][2];
	struct _lowpass lowpass[4][2];
	signed long int in[2][2];
	signed long int out[2][2];
};

struct _env {
	float time;
	float level;
	unsigned char set;
};

struct _sample {
	unsigned long int data_length;
	unsigned long int loop_start;
	unsigned long int loop_end;
	unsigned long int loop_size;
	unsigned char loop_fraction;
	unsigned short int rate;
	unsigned long int freq_low;
	unsigned long int freq_high;
	unsigned long int freq_root;
	unsigned char modes;
	unsigned long int env_rate[7];
	unsigned long int env_target[7];
	unsigned long int inc_div;
	signed short *data;
	signed short max_peek;
	signed short min_peek;
	signed long int peek_adjust;
	struct _sample *next;
};

struct _patch {
	unsigned short patchid;
	unsigned char loaded;
	char *filename;
	signed short int amp;
	unsigned char keep;
	unsigned char remove;
	struct _env env[6];
	unsigned char note;
	unsigned long int inuse_count;
	struct _sample *first_sample;
	struct _patch *next;
};

struct _patch *patch[128];

int patch_lock;

struct _channel {
	unsigned char bank;
	struct _patch *patch;