timidity_playmidi.cpp

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/*

    TiMidity -- Experimental MIDI to WAVE converter
    Copyright (C) 1995 Tuukka Toivonen <toivonen@clinet.fi>

    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., 675 Mass Ave, Cambridge, MA 02139, USA.

    playmidi.c -- random stuff in need of rearrangement

*/

#include "pent_include.h"

#ifdef USE_TIMIDITY_MIDI

#include <cstdio>
#include <cstdlib>
#include <cstring>

#include "timidity.h"
#include "timidity_common.h"
#include "timidity_instrum.h"
#include "timidity_playmidi.h"
#include "timidity_readmidi.h"
#include "timidity_output.h"
#include "timidity_mix.h"
#include "timidity_controls.h"
#include "timidity_tables.h"

#ifdef NS_TIMIDITY
namespace NS_TIMIDITY {
#endif

Channel channel[16];
Voice voice[MAX_VOICES];

int
    voices=DEFAULT_VOICES;

sint32
    control_ratio=0,
    amplification=DEFAULT_AMPLIFICATION;

float
    master_volume;

sint32 drumchannels=DEFAULT_DRUMCHANNELS;
int adjust_panning_immediately=1;

struct MidiSong {
        sint32 samples;
        MidiEvent *events;
};
static int midi_playing = 0;
static sint32 lost_notes, cut_notes;
static sint32 *buffer_pointer;
static sint32 buffered_count;
extern sint32 *common_buffer;

static MidiEvent *event_list, *current_event;
static sint32 sample_count, current_sample;

static void adjust_amplification(void)
{ 
  master_volume = (float)(amplification) / (float)100.0;
}

static void reset_voices(void)
{
  int i;
  for (i=0; i<MAX_VOICES; i++)
    voice[i].status=VOICE_FREE;
}

/* Process the Reset All Controllers event */
static void reset_controllers(int c)
{
  channel[c].volume=90; /* Some standard says, although the SCC docs say 0. */
  channel[c].expression=127; /* SCC-1 does this. */
  channel[c].sustain=0;
  channel[c].pitchbend=0x2000;
  channel[c].pitchfactor=0; /* to be computed */
}

static void redraw_controllers(int c)
{
  ctl->volume(c, channel[c].volume);
  ctl->expression(c, channel[c].expression);
  ctl->sustain(c, channel[c].sustain);
  ctl->pitch_bend(c, channel[c].pitchbend);
}

static void reset_midi(void)
{
  int i;
  for (i=0; i<16; i++)
    {
      reset_controllers(i);
      /* The rest of these are unaffected by the Reset All Controllers event */
      channel[i].program=default_program;
      channel[i].panning=NO_PANNING;
      channel[i].pitchsens=2;
      channel[i].bank=0; /* tone bank or drum set */
    }
  reset_voices();
}

static void select_sample(int v, Instrument *ip)
{
  sint32 f, cdiff, diff;
  int s,i;
  Sample *sp, *closest;

  s=ip->samples;
  sp=ip->sample;

  if (s==1)
    {
      voice[v].sample=sp;
      return;
    }

  f=voice[v].orig_frequency;
  for (i=0; i<s; i++)
    {
      if (sp->low_freq <= f && sp->high_freq >= f)
        {
          voice[v].sample=sp;
          return;
        }
      sp++;
    }

  /* 
     No suitable sample found! We'll select the sample whose root
     frequency is closest to the one we want. (Actually we should
     probably convert the low, high, and root frequencies to MIDI note
     values and compare those.) */

  cdiff=0x7FFFFFFF;
  closest=sp=ip->sample;
  for(i=0; i<s; i++)
    {
      diff=sp->root_freq - f;
      if (diff<0) diff=-diff;
      if (diff<cdiff)
        {
          cdiff=diff;
          closest=sp;
        }
      sp++;
    }
  voice[v].sample=closest;
  return;
}

static void recompute_freq(int v)
{
  int 
    sign=(voice[v].sample_increment < 0), /* for bidirectional loops */
    pb=channel[voice[v].channel].pitchbend;
  double a;
  
  if (!voice[v].sample->sample_rate)
    return;

  if (voice[v].vibrato_control_ratio)
    {
      /* This instrument has vibrato. Invalidate any precomputed
         sample_increments. */

      int i=VIBRATO_SAMPLE_INCREMENTS;
      while (i--)
        voice[v].vibrato_sample_increment[i]=0;
    }

  if (pb==0x2000 || pb<0 || pb>0x3FFF)
    voice[v].frequency=voice[v].orig_frequency;
  else
    {
      pb-=0x2000;
      if (!(channel[voice[v].channel].pitchfactor))
        {
          /* Damn. Somebody bent the pitch. */
          sint32 i=pb*channel[voice[v].channel].pitchsens;
          if (pb<0)
            i=-i;
          channel[voice[v].channel].pitchfactor=
            (float)(bend_fine[(i>>5) & 0xFF] * bend_coarse[i>>13]);
        }
      if (pb>0)
        voice[v].frequency=
          (sint32)(channel[voice[v].channel].pitchfactor *
                  (double)(voice[v].orig_frequency));
      else
        voice[v].frequency=
          (sint32)((double)(voice[v].orig_frequency) /
                  channel[voice[v].channel].pitchfactor);
    }

  a = FSCALE(((double)(voice[v].sample->sample_rate) *
              (double)(voice[v].frequency)) /
             ((double)(voice[v].sample->root_freq) *
              (double)(play_mode->rate)),
             FRACTION_BITS);

  if (sign) 
    a = -a; /* need to preserve the loop direction */

  voice[v].sample_increment = (sint32)(a);
}

static void recompute_amp(int v)
{
  sint32 tempamp;

  /* TODO: use fscale */

  tempamp= (voice[v].velocity *
            channel[voice[v].channel].volume * 
            channel[voice[v].channel].expression); /* 21 bits */

  if (!(play_mode->encoding & PE_MONO))
    {
      if (voice[v].panning > 60 && voice[v].panning < 68)
        {
          voice[v].panned=PANNED_CENTER;

          voice[v].left_amp=
            FSCALENEG((double)(tempamp) * voice[v].sample->volume * master_volume,
                      21);
        }
      else if (voice[v].panning<5)
        {
          voice[v].panned = PANNED_LEFT;

          voice[v].left_amp=
            FSCALENEG((double)(tempamp) * voice[v].sample->volume * master_volume,
                      20);
        }
      else if (voice[v].panning>123)
        {
          voice[v].panned = PANNED_RIGHT;

          voice[v].left_amp= /* left_amp will be used */
            FSCALENEG((double)(tempamp) * voice[v].sample->volume * master_volume,
                      20);
        }
      else
        {
          voice[v].panned = PANNED_MYSTERY;

          voice[v].left_amp=
            FSCALENEG((double)(tempamp) * voice[v].sample->volume * master_volume,
                      27);
          voice[v].right_amp=voice[v].left_amp * (voice[v].panning);
          voice[v].left_amp *= (float)(127-voice[v].panning);
        }
    }
  else
    {
      voice[v].panned=PANNED_CENTER;

      voice[v].left_amp=
        FSCALENEG((double)(tempamp) * voice[v].sample->volume * master_volume,
                  21);
    }
}

static void start_note(MidiEvent *e, int i)
{
  Instrument *ip;
  int j;

  if (ISDRUMCHANNEL(e->channel))
    {
      if (!(ip=drumset[channel[e->channel].bank]->tone[e->a].instrument))
        {
          if (!(ip=drumset[0]->tone[e->a].instrument))
            return; /* No instrument? Then we can't play. */
        }
      if (ip->samples != 1)
        {
          ctl->cmsg(CMSG_WARNING, VERB_VERBOSE, 
               "Strange: percussion instrument with %d samples!", ip->samples);
        }

      if (ip->sample->note_to_use) /* Do we have a fixed pitch? */
        voice[i].orig_frequency=freq_table[(int)(ip->sample->note_to_use)];
      else
        voice[i].orig_frequency=freq_table[e->a & 0x7F];
      
      /* drums are supposed to have only one sample */
      voice[i].sample=ip->sample;
    }
  else
    {
      if (channel[e->channel].program==SPECIAL_PROGRAM)
        ip=default_instrument;
      else if (!(ip=tonebank[channel[e->channel].bank]->
                 tone[channel[e->channel].program].instrument))
        {
          if (!(ip=tonebank[0]->tone[channel[e->channel].program].instrument))
            return; /* No instrument? Then we can't play. */
        }

      if (ip->sample->note_to_use) /* Fixed-pitch instrument? */
        voice[i].orig_frequency=freq_table[(int)(ip->sample->note_to_use)];
      else
        voice[i].orig_frequency=freq_table[e->a & 0x7F];
      select_sample(i, ip);
    }

  voice[i].status=VOICE_ON;
  voice[i].channel=e->channel;
  voice[i].note=e->a;
  voice[i].velocity=e->b;
  voice[i].sample_offset=0;
  voice[i].sample_increment=0; /* make sure it isn't negative */

  voice[i].tremolo_phase=0;
  voice[i].tremolo_phase_increment=voice[i].sample->tremolo_phase_increment;
  voice[i].tremolo_sweep=voice[i].sample->tremolo_sweep_increment;
  voice[i].tremolo_sweep_position=0;

  voice[i].vibrato_sweep=voice[i].sample->vibrato_sweep_increment;
  voice[i].vibrato_sweep_position=0;
  voice[i].vibrato_control_ratio=voice[i].sample->vibrato_control_ratio;
  voice[i].vibrato_control_counter=voice[i].vibrato_phase=0;
  for (j=0; j<VIBRATO_SAMPLE_INCREMENTS; j++)
    voice[i].vibrato_sample_increment[j]=0;

  if (channel[e->channel].panning != NO_PANNING)
    voice[i].panning=channel[e->channel].panning;
  else
    voice[i].panning=voice[i].sample->panning;

  recompute_freq(i);
  recompute_amp(i);
  if (voice[i].sample->modes & MODES_ENVELOPE)
    {
      /* Ramp up from 0 */
      voice[i].envelope_stage=0;
      voice[i].envelope_volume=0;
      voice[i].control_counter=0;
      recompute_envelope(i);
      apply_envelope_to_amp(i);
    }
  else
    {
      voice[i].envelope_increment=0;
      apply_envelope_to_amp(i);
    }
  ctl->note(i);
}

static void kill_note(int i)
{
  voice[i].status=VOICE_DIE;
  ctl->note(i);
}

/* Only one instance of a note can be playing on a single channel. */
static void note_on(MidiEvent *e)
{
  int i=voices, lowest=-1; 
  sint32 lv=0x7FFFFFFF, v;

  while (i--)
    {
      if (voice[i].status == VOICE_FREE)
        lowest=i; /* Can't get a lower volume than silence */
      else if (voice[i].channel==e->channel && 
               (voice[i].note==e->a || channel[voice[i].channel].mono))
        kill_note(i);
    }

  if (lowest != -1)
    {
      /* Found a free voice. */
      start_note(e,lowest);
      return;
    }
  
  /* Look for the decaying note with the lowest volume */
  i=voices;
  while (i--)
    {
      if ((voice[i].status!=VOICE_ON) &&
          (voice[i].status!=VOICE_DIE))
        {
          v=voice[i].left_mix;
          if ((voice[i].panned==PANNED_MYSTERY) && (voice[i].right_mix>v))
            v=voice[i].right_mix;
          if (v<lv)
            {
              lv=v;
              lowest=i;
            }
        }
    }

  if (lowest != -1)
    {
      /* This can still cause a click, but if we had a free voice to
         spare for ramping down this note, we wouldn't need to kill it
         in the first place... Still, this needs to be fixed. Perhaps
         we could use a reserve of voices to play dying notes only. */
      
      cut_notes++;
      voice[lowest].status=VOICE_FREE;
      ctl->note(lowest);
      start_note(e,lowest);
    }
  else
    lost_notes++;
}

static void finish_note(int i)
{
  if (voice[i].sample->modes & MODES_ENVELOPE)
    {
      /* We need to get the envelope out of Sustain stage */
      voice[i].envelope_stage=3;
      voice[i].status=VOICE_OFF;
      recompute_envelope(i);
      apply_envelope_to_amp(i);
      ctl->note(i);
    }
  else
    {
      /* Set status to OFF so resample_voice() will let this voice out
         of its loop, if any. In any case, this voice dies when it
         hits the end of its data (ofs>=data_length). */
      voice[i].status=VOICE_OFF;
    }
}

static void note_off(MidiEvent *e)
{
  int i=voices;
  while (i--)
    if (voice[i].status==VOICE_ON &&
        voice[i].channel==e->channel &&
        voice[i].note==e->a)
      {
        if (channel[e->channel].sustain)
          {
            voice[i].status=VOICE_SUSTAINED;
            ctl->note(i);
          }
        else
          finish_note(i);
        return;
      }
}

/* Process the All Notes Off event */
static void all_notes_off(int c)
{
  int i=voices;
  ctl->cmsg(CMSG_INFO, VERB_DEBUG, "All notes off on channel %d", c);
  while (i--)
    if (voice[i].status==VOICE_ON &&
        voice[i].channel==c)
      {
        if (channel[c].sustain) 
          {
            voice[i].status=VOICE_SUSTAINED;
            ctl->note(i);
          }
        else
          finish_note(i);
      }
}

/* Process the All Sounds Off event */
static void all_sounds_off(int c)
{
  int i=voices;
  while (i--)
    if (voice[i].channel==c && 
        voice[i].status != VOICE_FREE &&
        voice[i].status != VOICE_DIE)
      {
        kill_note(i);
      }
}

static void adjust_pressure(MidiEvent *e)
{
  int i=voices;
  while (i--)
    if (voice[i].status==VOICE_ON &&
        voice[i].channel==e->channel &&
        voice[i].note==e->a)
      {
        voice[i].velocity=e->b;
        recompute_amp(i);
        apply_envelope_to_amp(i);
        return;
      }
}

static void adjust_panning(int c)
{
  int i=voices;
  while (i--)
    if ((voice[i].channel==c) &&
        (voice[i].status==VOICE_ON || voice[i].status==VOICE_SUSTAINED))
      {
        voice[i].panning=channel[c].panning;
        recompute_amp(i);
        apply_envelope_to_amp(i);
      }
}

static void drop_sustain(int c)
{
  int i=voices;
  while (i--)
    if (voice[i].status==VOICE_SUSTAINED && voice[i].channel==c)
      finish_note(i);
}

static void adjust_pitchbend(int c)
{
  int i=voices;
  while (i--)
    if (voice[i].status!=VOICE_FREE && voice[i].channel==c)
      {
        recompute_freq(i);
      }
}

static void adjust_volume(int c)
{
  int i=voices;
  while (i--)
    if (voice[i].channel==c &&
        (voice[i].status==VOICE_ON || voice[i].status==VOICE_SUSTAINED))
      {
        recompute_amp(i);
        apply_envelope_to_amp(i);
      }
}

static void seek_forward(sint32 until_time)
{
  reset_voices();
  while (current_event->time < until_time)
    {
      switch(current_event->type)
        {
          /* All notes stay off. Just handle the parameter changes. */

        case ME_PITCH_SENS:
          channel[current_event->channel].pitchsens=
            current_event->a;
          channel[current_event->channel].pitchfactor=0;
          break;
          
        case ME_PITCHWHEEL:
          channel[current_event->channel].pitchbend=
            current_event->a + current_event->b * 128;
          channel[current_event->channel].pitchfactor=0;
          break;
          
        case ME_MAINVOLUME:
          channel[current_event->channel].volume=current_event->a;
          break;
          
        case ME_PAN:
          channel[current_event->channel].panning=current_event->a;
          break;
              
        case ME_EXPRESSION:
          channel[current_event->channel].expression=current_event->a;
          break;
          
        case ME_PROGRAM:
          if (ISDRUMCHANNEL(current_event->channel))
            /* Change drum set */
            channel[current_event->channel].bank=current_event->a;
          else
            channel[current_event->channel].program=current_event->a;
          break;

        case ME_SUSTAIN:
          channel[current_event->channel].sustain=current_event->a;
          break;

        case ME_RESET_CONTROLLERS:
          reset_controllers(current_event->channel);
          break;
              
        case ME_TONE_BANK:
          channel[current_event->channel].bank=current_event->a;
          break;
          
        case ME_EOT:
          current_sample=current_event->time;
          return;
        }
      current_event++;
    }
  /*current_sample=current_event->time;*/
  if (current_event != event_list)
    current_event--;
  current_sample=until_time;
}

static void skip_to(sint32 until_time)
{
  if (current_sample > until_time)
    current_sample=0;

  reset_midi();
  buffered_count=0;
  buffer_pointer=common_buffer;
  current_event=event_list;
  
  if (until_time)
    seek_forward(until_time);
  ctl->reset();
}

static int apply_controls(void)
{
  int rc, i, did_skip=0;
  sint32 val;
  /* ASCII renditions of CD player pictograms indicate approximate effect */
  do
    switch(rc=ctl->read(&val))
      {
      case TM_RC_QUIT: /* [] */
      case TM_RC_LOAD_FILE:       
      case TM_RC_NEXT: /* >>| */
      case TM_RC_REALLY_PREVIOUS: /* |<< */
        return rc;
        
      case TM_RC_CHANGE_VOLUME:
        if (val>0 || amplification > -val)
          amplification += val;
        else 
          amplification=0;
        if (amplification > MAX_AMPLIFICATION)
          amplification=MAX_AMPLIFICATION;
        adjust_amplification();
        for (i=0; i<voices; i++)
          if (voice[i].status != VOICE_FREE)
            {
              recompute_amp(i);
              apply_envelope_to_amp(i);
            }
        ctl->master_volume(amplification);
        break;

      case TM_RC_PREVIOUS: /* |<< */
        if (current_sample < 2*play_mode->rate)
          return TM_RC_REALLY_PREVIOUS;
        return TM_RC_RESTART;

      case TM_RC_RESTART: /* |<< */
        skip_to(0);
        did_skip=1;
        break;
        
      case TM_RC_JUMP:
        if (val >= sample_count)
          return TM_RC_NEXT;
        skip_to(val);
        return rc;
        
      case TM_RC_FORWARD: /* >> */
        if (val+current_sample >= sample_count)
          return TM_RC_NEXT;
        skip_to(val+current_sample);
        did_skip=1;
        break;
        
      case TM_RC_BACK: /* << */
        if (current_sample > val)
          skip_to(current_sample-val);
        else
          skip_to(0); /* We can't seek to end of previous song. */
        did_skip=1;
        break;
      }
  while (rc!= TM_RC_NONE);
 
  /* Advertise the skip so that we stop computing the audio buffer */
  if (did_skip)
    return TM_RC_JUMP; 
  else
    return rc;
}

static void do_compute_data(sint32 count)
{
  int i;
  memset(buffer_pointer, 0, 
         (play_mode->encoding & PE_MONO) ? (count * 4) : (count * 8));
  for (i=0; i<voices; i++)
    {
      if(voice[i].status != VOICE_FREE)
        mix_voice(buffer_pointer, i, count);
    }
  current_sample += count;
}

/* count=0 means flush remaining buffered data to output device, then
   flush the device itself */
static int compute_data(void *stream, sint32 count)
{
  int rc, channels;

  if ( play_mode->encoding & PE_MONO )
    channels = 1;
  else
    channels = 2;

  if (!count)
    {
      if (buffered_count)
          s32tobuf(stream, common_buffer, channels*buffered_count);
      buffer_pointer=common_buffer;
      buffered_count=0;
      return TM_RC_NONE;
    }

  while ((count+buffered_count) >= AUDIO_BUFFER_SIZE)
    {
      do_compute_data(AUDIO_BUFFER_SIZE-buffered_count);
      count -= AUDIO_BUFFER_SIZE-buffered_count;
      s32tobuf(stream, common_buffer, channels*AUDIO_BUFFER_SIZE);
      buffer_pointer=common_buffer;
      buffered_count=0;
      
      ctl->current_time(current_sample);
      if ((rc=apply_controls())!=TM_RC_NONE)
        return rc;
    }
  if (count>0)
    {
      do_compute_data(count);
      buffered_count += count;
      buffer_pointer += (play_mode->encoding & PE_MONO) ? count : count*2;
    }
  return TM_RC_NONE;
}

int Timidity_PlaySome(void *stream, int samples)
{
  int rc = TM_RC_NONE;
  sint32 end_sample;
  
  if ( ! midi_playing ) {
    return TM_RC_NONE;
  }
  end_sample = current_sample+samples;
  while ( current_sample < end_sample ) {
    /* Handle all events that should happen at this time */
    while (current_event->time <= current_sample) {
      switch(current_event->type) {

        /* Effects affecting a single note */

        case ME_NOTEON:
          if (!(current_event->b)) /* Velocity 0? */
            note_off(current_event);
          else
            note_on(current_event);
          break;
  
        case ME_NOTEOFF:
          note_off(current_event);
          break;
  
        case ME_KEYPRESSURE:
          adjust_pressure(current_event);
          break;
  
          /* Effects affecting a single channel */
  
        case ME_PITCH_SENS:
          channel[current_event->channel].pitchsens=current_event->a;
          channel[current_event->channel].pitchfactor=0;
          break;
          
        case ME_PITCHWHEEL:
          channel[current_event->channel].pitchbend=
            current_event->a + current_event->b * 128;
          channel[current_event->channel].pitchfactor=0;
          /* Adjust pitch for notes already playing */
          adjust_pitchbend(current_event->channel);
          ctl->pitch_bend(current_event->channel, 
              channel[current_event->channel].pitchbend);
          break;
          
        case ME_MAINVOLUME:
          channel[current_event->channel].volume=current_event->a;
          adjust_volume(current_event->channel);
          ctl->volume(current_event->channel, current_event->a);
          break;
          
        case ME_PAN:
          channel[current_event->channel].panning=current_event->a;
          if (adjust_panning_immediately)
            adjust_panning(current_event->channel);
          ctl->panning(current_event->channel, current_event->a);
          break;
          
        case ME_EXPRESSION:
          channel[current_event->channel].expression=current_event->a;
          adjust_volume(current_event->channel);
          ctl->expression(current_event->channel, current_event->a);
          break;
  
        case ME_PROGRAM:
          if (ISDRUMCHANNEL(current_event->channel)) {
            /* Change drum set */
            channel[current_event->channel].bank=current_event->a;
          }
          else
          {
            channel[current_event->channel].program=current_event->a;
          }
          ctl->program(current_event->channel, current_event->a);
          break;
  
        case ME_SUSTAIN:
          channel[current_event->channel].sustain=current_event->a;
          if (!current_event->a)
            drop_sustain(current_event->channel);
          ctl->sustain(current_event->channel, current_event->a);
          break;
          
        case ME_RESET_CONTROLLERS:
          reset_controllers(current_event->channel);
          redraw_controllers(current_event->channel);
          break;
  
        case ME_ALL_NOTES_OFF:
          all_notes_off(current_event->channel);
          break;
          
        case ME_ALL_SOUNDS_OFF:
          all_sounds_off(current_event->channel);
          break;
          
        case ME_TONE_BANK:
          channel[current_event->channel].bank=current_event->a;
          break;
  
        case ME_EOT:
          /* Give the last notes a couple of seconds to decay  */
          ctl->cmsg(CMSG_INFO, VERB_VERBOSE,
            "Playing time: ~%d seconds", current_sample/play_mode->rate+2);
          ctl->cmsg(CMSG_INFO, VERB_VERBOSE,
            "Notes cut: %d", cut_notes);
          ctl->cmsg(CMSG_INFO, VERB_VERBOSE,
          "Notes lost totally: %d", lost_notes);
          midi_playing = 0;
          return TM_RC_TUNE_END;
        }
      current_event++;
    }
    if (current_event->time > end_sample)
      rc=compute_data(stream, end_sample-current_sample);
    else
      rc=compute_data(stream, current_event->time-current_sample);
    ctl->refresh();
    if ( (rc!=TM_RC_NONE) && (rc!=TM_RC_JUMP))
      break;
  }
  return rc;
}


void Timidity_SetVolume(int volume)
{
  int i;
  if (volume > MAX_AMPLIFICATION)
    amplification=MAX_AMPLIFICATION;
  else
  if (volume < 0)
    amplification=0;
  else
    amplification=volume;
  adjust_amplification();
  for (i=0; i<voices; i++)
    if (voice[i].status != VOICE_FREE)
      {
        recompute_amp(i);
        apply_envelope_to_amp(i);
      }
  ctl->master_volume(amplification);
}

MidiSong *Timidity_LoadSong(char *midifile)
{
  MidiSong *song;
  sint32 events;
  FILE *fp;

  /* Allocate memory for the song */
  song = safe_Malloc<MidiSong>();
  memset(song, 0, sizeof(*song));

  /* Open the file */
  fp = open_file(midifile, 1, OF_VERBOSE);
  if ( fp != NULL ) {
    song->events=read_midi_file(fp, &events, &song->samples);
    close_file(fp);
  }
  
  /* Make sure everything is okay */
  if (!song->events) {
    free(song);
    song = NULL;
  }
  return(song);
}

void Timidity_Start(MidiSong *song)
{
  load_missing_instruments();
  adjust_amplification();
  sample_count = song->samples;
  event_list = song->events;
  lost_notes=cut_notes=0;

  skip_to(0);
  midi_playing = 1;
}

int Timidity_Active(void)
{
        return(midi_playing);
}

void Timidity_Stop(void)
{
  midi_playing = 0;
}

void Timidity_FreeSong(MidiSong *song)
{
  if (free_instruments_afterwards)
      free_instruments();
  
  free(song->events);
  free(song);
}

/* Pentagram Extensions to Timidity Lib */

#define MIDIEVENT(t,ch,pa,pb) \
  event.time=0; event.type=t; event.channel=ch; \
  event.a=(uint8)pa; event.b=(uint8)pb; 

void Timidity_PlayEvent(unsigned char status, int a, int b)
{
        MidiEvent event;
        uint8 chan=status & 0x0F;

        switch((status>>4) & 0x07)
        {
        case 0: /* Note off */
                MIDIEVENT(ME_NOTEOFF, chan, a,b);
                note_off(&event);
                return;

        case 1: /* Note on */
                MIDIEVENT(ME_NOTEON, chan, a,b);
        if (b) note_on(&event);
        else note_off(&event);
                return;

        case 2: /* Key Pressure */
                MIDIEVENT(ME_KEYPRESSURE, chan, a, b);
                adjust_pressure(&event);
                return;

        case 3: /* Control change */
                switch(a)
                {
                case 0:                 /* Bank - This is not needed for Pentagram */
                        return;

                case 7:                 /* Volume */
                        channel[chan].volume=b;
                        adjust_volume(chan);
                        ctl->volume(chan, b);
                        return;

                case 10:                /* Pan */
                        channel[chan].panning=b;
                        if (adjust_panning_immediately)
                                adjust_panning(chan);
                        ctl->panning(chan, b);
                        return;

                case 11:                /* Expression */
                        channel[chan].expression=b;
                        adjust_volume(chan);
                        ctl->expression(chan, b);
                        return;

                case 64:                /* Sustain*/
                        channel[chan].sustain=b;
                        if (!b) drop_sustain(chan);
                        ctl->sustain(chan, b);
                        return;

                case 120:               /* All Sounds Off */
                all_sounds_off(chan);
                        return;
                                
                case 121:               /* Reset Controllers */
                    reset_controllers(chan);
                redraw_controllers(chan);
                        return;

                case 123:               /* All notes off */
                        all_notes_off(chan);
                        return;

                default:
                        return;
                }

        case 4: /* Program change */
        if (chan!=9) {
                channel[chan].program=a;
                ctl->program(chan, a);
                }
        return;

        case 5: /* Channel pressure - NOT IMPLEMENTED */
                return;

        case 6: /* Pitch wheel */
        channel[chan].pitchbend= a + b * 128;
        channel[chan].pitchfactor=0;
        /* Adjust pitch for notes already playing */
        adjust_pitchbend(chan);
        ctl->pitch_bend(chan, channel[chan].pitchbend);
                return;

        default: 
                return;
        }
}

void Timidity_GenerateSamples(void *stream, int samples)
{
        int channels;

        if ( play_mode->encoding & PE_MONO )
                channels = 1;
        else
                channels = 2;

        int sample_size = channels;

        if ( play_mode->encoding & PE_16BIT )
                sample_size *= 2;

        buffer_pointer=common_buffer;
        buffered_count=0;

        while (samples >= AUDIO_BUFFER_SIZE)
        {
                do_compute_data(AUDIO_BUFFER_SIZE);
                samples -= AUDIO_BUFFER_SIZE;
                s32tobuf(stream, common_buffer, channels*AUDIO_BUFFER_SIZE);
                stream = AUDIO_BUFFER_SIZE*sample_size + (uint8*)stream;
                buffer_pointer=common_buffer;
                buffered_count=0;
        }

        if (samples)
        {
                do_compute_data(samples);
                s32tobuf(stream, common_buffer, channels*samples);
                buffer_pointer=common_buffer;
                buffered_count=0;
        }
}

void Timidity_FinalInit(bool patches[128], bool drums[128])
{
        for (int i = 0; i < 128; i++)
        {
                if (patches[i])
                {
                        /* Mark this instrument to be loaded */
                        if (!(tonebank[0]->tone[i].instrument))
                                tonebank[0]->tone[i].instrument=MAGIC_LOAD_INSTRUMENT;
                }
                if (drums[i])
                {
                        /* Mark this instrument to be loaded */
                        if (!(drumset[0]->tone[i].instrument))
                                drumset[0]->tone[i].instrument=MAGIC_LOAD_INSTRUMENT;
                }
        }

        load_missing_instruments();
        adjust_amplification();
        sample_count = 0x7FFFFFF;
        event_list = 0;
        lost_notes=cut_notes=0;
        skip_to(0);
        midi_playing = 1;
}

#ifdef NS_TIMIDITY
};
#endif

#endif //USE_TIMIDITY_MIDI

---