ref: f25e3e2d6ee2be725eade97fef60e615ff7f7177
dir: /src/mus2mid.c/
// Emacs style mode select -*- C++ -*-
//-----------------------------------------------------------------------------
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005 Simon Howard
// Copyright(C) 2006 Ben Ryves 2006
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
// 02111-1307, USA.
//
// mus2mid.c - Ben Ryves 2006 - http://benryves.com - benryves@benryves.com
// Use to convert a MUS file into a single track, type 0 MIDI file.
#include <stdio.h>
#include "memio.h"
#include "mus2mid.h"
// MUS event codes
typedef enum
{
mus_releasekey = 0x00,
mus_presskey = 0x10,
mus_pitchwheel = 0x20,
mus_systemevent = 0x30,
mus_changecontroller = 0x40,
mus_scoreend = 0x60
} musevent;
// MIDI event codes
typedef enum
{
midi_releasekey = 0x80,
midi_presskey = 0x90,
midi_aftertouchkey = 0xA0,
midi_changecontroller = 0xB0,
midi_changepatch = 0xC0,
midi_aftertouchchannel = 0xD0,
midi_pitchwheel = 0xE0
} midievent;
// Structure to hold MUS file header
typedef struct
{
unsigned char id[4];
unsigned short scorelength;
unsigned short scorestart;
unsigned short primarychannels;
unsigned short secondarychannels;
unsigned short instrumentcount;
} musheader;
// Standard MIDI type 0 header + track header
static unsigned char midiheader[] =
{
'M', 'T', 'h', 'd', // Main header
0x00, 0x00, 0x00, 0x06, // Header size
0x00, 0x00, // MIDI type (0)
0x00, 0x01, // Number of tracks
0x00, 0x46, // Resolution
'M', 'T', 'r', 'k', // Start of track
0x00, 0x00, 0x00, 0x00 // Placeholder for track length
};
// Cached channel velocities
static unsigned char channelvelocities[] =
{
127, 127, 127, 127, 127, 127, 127, 127,
127, 127, 127, 127, 127, 127, 127, 127
};
// Timestamps between sequences of MUS events
static unsigned int queuedtime = 0;
// Counter for the length of the track
static unsigned int tracksize = 0;
static unsigned char mus2midi_translation[] =
{
0x00, 0x20, 0x01, 0x07, 0x0A, 0x0B, 0x5B, 0x5D,
0x40, 0x43, 0x78, 0x7B, 0x7E, 0x7F, 0x79
};
// Write timestamp to a MIDI file.
static int midi_writetime(unsigned int time, MEMFILE *midioutput)
{
unsigned int buffer = time & 0x7F;
unsigned char writeval;
while ((time >>= 7) != 0)
{
buffer <<= 8;
buffer |= ((time & 0x7F) | 0x80);
}
for (;;)
{
writeval = (unsigned char)(buffer & 0xFF);
if (mem_fwrite(&writeval, 1, 1, midioutput) != 1)
{
return 1;
}
++tracksize;
if ((buffer & 0x80) != 0)
{
buffer >>= 8;
}
else
{
queuedtime = 0;
return 0;
}
}
}
// Write the end of track marker
static int midi_writeendtrack(MEMFILE *midioutput)
{
unsigned char endtrack[] = {0xFF, 0x2F, 0x00};
if (midi_writetime(queuedtime, midioutput))
{
return 1;
}
if (mem_fwrite(endtrack, 1, 3, midioutput) != 3)
{
return 1;
}
tracksize += 3;
return 0;
}
// Write a key press event
static int midi_writepresskey(unsigned char channel, unsigned char key,
unsigned char velocity, MEMFILE *midioutput)
{
unsigned char working = midi_presskey | channel;
if (midi_writetime(queuedtime, midioutput))
{
return 1;
}
if (mem_fwrite(&working, 1, 1, midioutput) != 1)
{
return 1;
}
working = key & 0x7F;
if (mem_fwrite(&working, 1, 1, midioutput) != 1)
{
return 1;
}
working = velocity & 0x7F;
if (mem_fwrite(&working, 1, 1, midioutput) != 1)
{
return 1;
}
tracksize += 3;
return 0;
}
// Write a key release event
static int midi_writereleasekey(unsigned char channel, unsigned char key,
MEMFILE *midioutput)
{
unsigned char working = midi_releasekey | channel;
if (midi_writetime(queuedtime, midioutput))
{
return 1;
}
if (mem_fwrite(&working, 1, 1, midioutput) != 1)
{
return 1;
}
working = key & 0x7F;
if (mem_fwrite(&working, 1, 1, midioutput) != 1)
{
return 1;
}
working = 0;
if (mem_fwrite(&working, 1, 1, midioutput) != 1)
{
return 1;
}
tracksize += 3;
return 0;
}
// Write a pitch wheel/bend event
static int midi_writepitchwheel(unsigned char channel, short wheel,
MEMFILE *midioutput)
{
unsigned char working = midi_pitchwheel | channel;
if (midi_writetime(queuedtime, midioutput))
{
return 1;
}
if (mem_fwrite(&working, 1, 1, midioutput) != 1)
{
return 1;
}
working = wheel & 0x7F;
if (mem_fwrite(&working, 1, 1, midioutput) != 1)
{
return 1;
}
working = (wheel >> 7) & 0x7F;
if (mem_fwrite(&working, 1, 1, midioutput) != 1)
{
return 1;
}
tracksize += 3;
return 0;
}
// Write a patch change event
static int midi_writechangepatch(unsigned char channel, unsigned char patch,
MEMFILE *midioutput)
{
unsigned char working = midi_changepatch | channel;
if (midi_writetime(queuedtime, midioutput))
{
return 1;
}
if (mem_fwrite(&working, 1, 1, midioutput) != 1)
{
return 1;
}
working = patch & 0x7F;
if (mem_fwrite(&working, 1, 1, midioutput) != 1)
{
return 1;
}
tracksize += 2;
return 0;
}
// Write a valued controller change event
static int midi_writechangecontroller_valued(unsigned char channel,
unsigned char control,
unsigned char value,
MEMFILE *midioutput)
{
unsigned char working = midi_changecontroller | channel;
if (midi_writetime(queuedtime, midioutput))
{
return 1;
}
if (mem_fwrite(&working, 1, 1, midioutput) != 1)
{
return 1;
}
working = control & 0x7F;
if (mem_fwrite(&working, 1, 1, midioutput) != 1)
{
return 1;
}
// Quirk in vanilla DOOM? MUS controller values should be
// 7-bit, not 8-bit.
working = value;// & 0x7F;
// Fix on said quirk to stop MIDI players from complaining that
// the value is out of range:
if (working & 0x80)
{
working = 0x7F;
}
if (mem_fwrite(&working, 1, 1, midioutput) != 1)
{
return 1;
}
tracksize += 3;
return 0;
}
// Write a valueless controller change event
static int midi_writechangecontroller_valueless(unsigned char channel,
unsigned char control,
MEMFILE *midioutput)
{
return midi_writechangecontroller_valued(channel, control, 0,
midioutput);
}
// Read a MUS file from a stream (musinput) and output a MIDI file to
// a stream (midioutput).
//
// Returns 0 on success or 1 on failure.
int mus2mid(MEMFILE *musinput, MEMFILE *midioutput)
{
// Header for the MUS file
musheader musfileheader;
// Descriptor for the current MUS event
unsigned char eventdescriptor;
int channel; // Channel number
musevent event;
// Bunch of vars read from MUS lump
unsigned char key;
unsigned char controllernumber;
unsigned char controllervalue;
// Buffer used for MIDI track size record
unsigned char tracksizebuffer[4];
// Flag for when the score end marker is hit.
int hitscoreend = 0;
// Temp working byte
unsigned char working;
// Used in building up time delays
unsigned int timedelay;
int i;
// Grab the header
if (mem_fread(&musfileheader, sizeof(musheader), 1, musinput) != 1)
{
return 1;
}
#ifdef CHECK_MUS_HEADER
// Check MUS header
if (musfileheader.id[0] != 'M'
|| musfileheader.id[1] != 'U'
|| musfileheader.id[2] != 'S'
|| musfileheader.id[3] != 0x1A)
{
return 1;
}
#endif
// Seek to where the data is held
if (mem_fseek(musinput, (long)musfileheader.scorestart, SEEK_SET) != 0)
{
return 1;
}
// So, we can assume the MUS file is faintly legit. Let's start
// writing MIDI data...
mem_fwrite(midiheader, 1, 22, midioutput);
// Now, process the MUS file:
while (!hitscoreend)
{
// Handle a block of events:
while (!hitscoreend)
{
// Fetch channel number and event code:
if (mem_fread(&eventdescriptor, 1, 1, musinput) != 1)
{
return 1;
}
channel = eventdescriptor & 0x0F;
event = eventdescriptor & 0x70;
// Swap channels 15 and 9.
// MIDI channel 9 = percussion.
// MUS channel 15 = percussion.
if (channel == 15)
{
channel = 9;
}
else if (channel == 9)
{
channel = 15;
}
switch (event)
{
case mus_releasekey:
if (mem_fread(&key, 1, 1, musinput) != 1)
{
return 1;
}
if (midi_writereleasekey(channel, key, midioutput))
{
return 1;
}
break;
case mus_presskey:
if (mem_fread(&key, 1, 1, musinput) != 1)
{
return 1;
}
if (key & 0x80)
{
if (mem_fread(&channelvelocities[channel], 1, 1, musinput) != 1)
{
return 1;
}
channelvelocities[channel] &= 0x7F;
}
if (midi_writepresskey(channel, key, channelvelocities[channel], midioutput))
{
return 1;
}
break;
case mus_pitchwheel:
if (mem_fread(&key, 1, 1, musinput) != 1)
{
break;
}
if (midi_writepitchwheel(channel, (short)(key * 64), midioutput))
{
return 1;
}
break;
case mus_systemevent:
if (mem_fread(&controllernumber, 1, 1, musinput) != 1)
{
return 1;
}
if (controllernumber < 10 || controllernumber > 14)
{
return 1;
}
if (midi_writechangecontroller_valueless(channel, mus2midi_translation[controllernumber], midioutput))
{
return 1;
}
break;
case mus_changecontroller:
if (mem_fread(&controllernumber, 1, 1, musinput) != 1)
{
return 1;
}
if (mem_fread(&controllervalue, 1, 1, musinput) != 1)
{
return 1;
}
if (controllernumber == 0)
{
if (midi_writechangepatch(channel, controllervalue, midioutput))
{
return 1;
}
}
else
{
if (controllernumber < 1 || controllernumber > 9)
{
return 1;
}
if (midi_writechangecontroller_valued(channel, mus2midi_translation[controllernumber], controllervalue, midioutput))
{
return 1;
}
}
break;
case mus_scoreend:
hitscoreend = 1;
break;
default:
return 1;
break;
}
if (eventdescriptor & 0x80)
{
break;
}
}
// Now we need to read the time code:
if (!hitscoreend)
{
timedelay = 0;
for (;;)
{
if (mem_fread(&working, 1, 1, musinput) != 1)
{
return 1;
}
timedelay = timedelay * 128 + (working & 0x7F);
if ((working & 0x80) == 0)
{
break;
}
}
queuedtime += timedelay;
}
}
// End of track
if (midi_writeendtrack(midioutput))
{
return 1;
}
// Write the track size into the stream
if (mem_fseek(midioutput, 18, SEEK_SET))
{
return 1;
}
for (i = 0; i < 4; ++i)
{
tracksizebuffer[i] = (unsigned char)(tracksize >> 24);
tracksize <<= 8;
}
if (mem_fwrite(tracksizebuffer, 1, 4, midioutput) != 4)
{
return 1;
}
return 0;
}