--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/decoders/timidity/playmidi.c	Fri Jan 04 06:49:49 2002 +0000
@@ -0,0 +1,800 @@
+/*
+
+    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
+
+*/
+
+#if HAVE_CONFIG_H
+#  include <config.h>
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "SDL_sound.h"
+
+#define __SDL_SOUND_INTERNAL__
+#include "SDL_sound_internal.h"
+
+#include "timidity.h"
+#include "options.h"
+#include "instrum.h"
+#include "playmidi.h"
+#include "output.h"
+#include "mix.h"
+#include "tables.h"
+
+static void adjust_amplification(MidiSong *song)
+{ 
+  song->master_volume = (float)(song->amplification) / (float)100.0;
+}
+
+static void reset_voices(MidiSong *song)
+{
+  int i;
+  for (i=0; i<MAX_VOICES; i++)
+    song->voice[i].status=VOICE_FREE;
+}
+
+/* Process the Reset All Controllers event */
+static void reset_controllers(MidiSong *song, int c)
+{
+  song->channel[c].volume=90; /* Some standard says, although the SCC docs say 0. */
+  song->channel[c].expression=127; /* SCC-1 does this. */
+  song->channel[c].sustain=0;
+  song->channel[c].pitchbend=0x2000;
+  song->channel[c].pitchfactor=0; /* to be computed */
+}
+
+static void reset_midi(MidiSong *song)
+{
+  int i;
+  for (i=0; i<16; i++)
+    {
+      reset_controllers(song, i);
+      /* The rest of these are unaffected by the Reset All Controllers event */
+      song->channel[i].program=song->default_program;
+      song->channel[i].panning=NO_PANNING;
+      song->channel[i].pitchsens=2;
+      song->channel[i].bank=0; /* tone bank or drum set */
+    }
+  reset_voices(song);
+}
+
+static void select_sample(MidiSong *song, int v, Instrument *ip)
+{
+  Sint32 f, cdiff, diff;
+  int s,i;
+  Sample *sp, *closest;
+
+  s=ip->samples;
+  sp=ip->sample;
+
+  if (s==1)
+    {
+      song->voice[v].sample=sp;
+      return;
+    }
+
+  f=song->voice[v].orig_frequency;
+  for (i=0; i<s; i++)
+    {
+      if (sp->low_freq <= f && sp->high_freq >= f)
+	{
+	  song->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++;
+    }
+  song->voice[v].sample=closest;
+  return;
+}
+
+static void recompute_freq(MidiSong *song, int v)
+{
+  int 
+    sign=(song->voice[v].sample_increment < 0), /* for bidirectional loops */
+    pb=song->channel[song->voice[v].channel].pitchbend;
+  double a;
+  
+  if (!song->voice[v].sample->sample_rate)
+    return;
+
+  if (song->voice[v].vibrato_control_ratio)
+    {
+      /* This instrument has vibrato. Invalidate any precomputed
+         sample_increments. */
+
+      int i=VIBRATO_SAMPLE_INCREMENTS;
+      while (i--)
+	song->voice[v].vibrato_sample_increment[i]=0;
+    }
+
+  if (pb==0x2000 || pb<0 || pb>0x3FFF)
+    song->voice[v].frequency = song->voice[v].orig_frequency;
+  else
+    {
+      pb-=0x2000;
+      if (!(song->channel[song->voice[v].channel].pitchfactor))
+	{
+	  /* Damn. Somebody bent the pitch. */
+	  Sint32 i=pb*song->channel[song->voice[v].channel].pitchsens;
+	  if (pb<0)
+	    i=-i;
+	  song->channel[song->voice[v].channel].pitchfactor=
+	    (float)(bend_fine[(i>>5) & 0xFF] * bend_coarse[i>>13]);
+	}
+      if (pb>0)
+	song->voice[v].frequency=
+	  (Sint32)(song->channel[song->voice[v].channel].pitchfactor *
+		  (double)(song->voice[v].orig_frequency));
+      else
+	song->voice[v].frequency=
+	  (Sint32)((double)(song->voice[v].orig_frequency) /
+		  song->channel[song->voice[v].channel].pitchfactor);
+    }
+
+  a = FSCALE(((double)(song->voice[v].sample->sample_rate) *
+	      (double)(song->voice[v].frequency)) /
+	     ((double)(song->voice[v].sample->root_freq) *
+	      (double)(song->rate)),
+	     FRACTION_BITS);
+
+  if (sign) 
+    a = -a; /* need to preserve the loop direction */
+
+  song->voice[v].sample_increment = (Sint32)(a);
+}
+
+static void recompute_amp(MidiSong *song, int v)
+{
+  Sint32 tempamp;
+
+  /* TODO: use fscale */
+
+  tempamp= (song->voice[v].velocity *
+	    song->channel[song->voice[v].channel].volume * 
+	    song->channel[song->voice[v].channel].expression); /* 21 bits */
+
+  if (!(song->encoding & PE_MONO))
+    {
+      if (song->voice[v].panning > 60 && song->voice[v].panning < 68)
+	{
+	  song->voice[v].panned=PANNED_CENTER;
+
+	  song->voice[v].left_amp=
+	    FSCALENEG((double)(tempamp) * song->voice[v].sample->volume * song->master_volume,
+		      21);
+	}
+      else if (song->voice[v].panning<5)
+	{
+	  song->voice[v].panned = PANNED_LEFT;
+
+	  song->voice[v].left_amp=
+	    FSCALENEG((double)(tempamp) * song->voice[v].sample->volume * song->master_volume,
+		      20);
+	}
+      else if (song->voice[v].panning>123)
+	{
+	  song->voice[v].panned = PANNED_RIGHT;
+
+	  song->voice[v].left_amp= /* left_amp will be used */
+	    FSCALENEG((double)(tempamp) * song->voice[v].sample->volume * song->master_volume,
+		      20);
+	}
+      else
+	{
+	  song->voice[v].panned = PANNED_MYSTERY;
+
+	  song->voice[v].left_amp=
+	    FSCALENEG((double)(tempamp) * song->voice[v].sample->volume * song->master_volume,
+		      27);
+	  song->voice[v].right_amp = song->voice[v].left_amp * (song->voice[v].panning);
+	  song->voice[v].left_amp *= (float)(127 - song->voice[v].panning);
+	}
+    }
+  else
+    {
+      song->voice[v].panned = PANNED_CENTER;
+
+      song->voice[v].left_amp=
+	FSCALENEG((double)(tempamp) * song->voice[v].sample->volume * song->master_volume,
+		  21);
+    }
+}
+
+static void start_note(MidiSong *song, MidiEvent *e, int i)
+{
+  Instrument *ip;
+  int j;
+
+  if (ISDRUMCHANNEL(song, e->channel))
+    {
+      if (!(ip=song->drumset[song->channel[e->channel].bank]->instrument[e->a]))
+	{
+	  if (!(ip=song->drumset[0]->instrument[e->a]))
+	    return; /* No instrument? Then we can't play. */
+	}
+      if (ip->samples != 1)
+	{
+	  SNDDBG(("Strange: percussion instrument with %d samples!",
+		  ip->samples));
+	}
+
+      if (ip->sample->note_to_use) /* Do we have a fixed pitch? */
+	song->voice[i].orig_frequency = freq_table[(int)(ip->sample->note_to_use)];
+      else
+	song->voice[i].orig_frequency = freq_table[e->a & 0x7F];
+      
+      /* drums are supposed to have only one sample */
+      song->voice[i].sample = ip->sample;
+    }
+  else
+    {
+      if (song->channel[e->channel].program == SPECIAL_PROGRAM)
+	ip=song->default_instrument;
+      else if (!(ip=song->tonebank[song->channel[e->channel].bank]->
+		 instrument[song->channel[e->channel].program]))
+	{
+	  if (!(ip=song->tonebank[0]->instrument[song->channel[e->channel].program]))
+	    return; /* No instrument? Then we can't play. */
+	}
+
+      if (ip->sample->note_to_use) /* Fixed-pitch instrument? */
+	song->voice[i].orig_frequency = freq_table[(int)(ip->sample->note_to_use)];
+      else
+	song->voice[i].orig_frequency = freq_table[e->a & 0x7F];
+      select_sample(song, i, ip);
+    }
+
+  song->voice[i].status = VOICE_ON;
+  song->voice[i].channel = e->channel;
+  song->voice[i].note = e->a;
+  song->voice[i].velocity = e->b;
+  song->voice[i].sample_offset = 0;
+  song->voice[i].sample_increment = 0; /* make sure it isn't negative */
+
+  song->voice[i].tremolo_phase = 0;
+  song->voice[i].tremolo_phase_increment = song->voice[i].sample->tremolo_phase_increment;
+  song->voice[i].tremolo_sweep = song->voice[i].sample->tremolo_sweep_increment;
+  song->voice[i].tremolo_sweep_position = 0;
+
+  song->voice[i].vibrato_sweep = song->voice[i].sample->vibrato_sweep_increment;
+  song->voice[i].vibrato_sweep_position = 0;
+  song->voice[i].vibrato_control_ratio = song->voice[i].sample->vibrato_control_ratio;
+  song->voice[i].vibrato_control_counter = song->voice[i].vibrato_phase = 0;
+  for (j=0; j<VIBRATO_SAMPLE_INCREMENTS; j++)
+    song->voice[i].vibrato_sample_increment[j] = 0;
+
+  if (song->channel[e->channel].panning != NO_PANNING)
+    song->voice[i].panning = song->channel[e->channel].panning;
+  else
+    song->voice[i].panning = song->voice[i].sample->panning;
+
+  recompute_freq(song, i);
+  recompute_amp(song, i);
+  if (song->voice[i].sample->modes & MODES_ENVELOPE)
+    {
+      /* Ramp up from 0 */
+      song->voice[i].envelope_stage = 0;
+      song->voice[i].envelope_volume = 0;
+      song->voice[i].control_counter = 0;
+      recompute_envelope(song, i);
+      apply_envelope_to_amp(song, i);
+    }
+  else
+    {
+      song->voice[i].envelope_increment = 0;
+      apply_envelope_to_amp(song, i);
+    }
+}
+
+static void kill_note(MidiSong *song, int i)
+{
+  song->voice[i].status = VOICE_DIE;
+}
+
+/* Only one instance of a note can be playing on a single channel. */
+static void note_on(MidiSong *song)
+{
+  int i = song->voices, lowest=-1; 
+  Sint32 lv=0x7FFFFFFF, v;
+  MidiEvent *e = song->current_event;
+
+  while (i--)
+    {
+      if (song->voice[i].status == VOICE_FREE)
+	lowest=i; /* Can't get a lower volume than silence */
+      else if (song->voice[i].channel==e->channel && 
+	       (song->voice[i].note==e->a || song->channel[song->voice[i].channel].mono))
+	kill_note(song, i);
+    }
+
+  if (lowest != -1)
+    {
+      /* Found a free voice. */
+      start_note(song,e,lowest);
+      return;
+    }
+  
+  /* Look for the decaying note with the lowest volume */
+  i = song->voices;
+  while (i--)
+    {
+      if ((song->voice[i].status != VOICE_ON) &&
+	  (song->voice[i].status != VOICE_DIE))
+	{
+	  v = song->voice[i].left_mix;
+	  if ((song->voice[i].panned == PANNED_MYSTERY)
+	      && (song->voice[i].right_mix > v))
+	    v = song->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. */
+      
+      song->cut_notes++;
+      song->voice[lowest].status=VOICE_FREE;
+      start_note(song,e,lowest);
+    }
+  else
+    song->lost_notes++;
+}
+
+static void finish_note(MidiSong *song, int i)
+{
+  if (song->voice[i].sample->modes & MODES_ENVELOPE)
+    {
+      /* We need to get the envelope out of Sustain stage */
+      song->voice[i].envelope_stage = 3;
+      song->voice[i].status = VOICE_OFF;
+      recompute_envelope(song, i);
+      apply_envelope_to_amp(song, 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). */
+      song->voice[i].status = VOICE_OFF;
+    }
+}
+
+static void note_off(MidiSong *song)
+{
+  int i = song->voices;
+  MidiEvent *e = song->current_event;
+
+  while (i--)
+    if (song->voice[i].status == VOICE_ON &&
+	song->voice[i].channel == e->channel &&
+	song->voice[i].note == e->a)
+      {
+	if (song->channel[e->channel].sustain)
+	  {
+	    song->voice[i].status = VOICE_SUSTAINED;
+	  }
+	else
+	  finish_note(song, i);
+	return;
+      }
+}
+
+/* Process the All Notes Off event */
+static void all_notes_off(MidiSong *song)
+{
+  int i = song->voices;
+  int c = song->current_event->channel;
+
+  SNDDBG(("All notes off on channel %d", c));
+  while (i--)
+    if (song->voice[i].status == VOICE_ON &&
+	song->voice[i].channel == c)
+      {
+	if (song->channel[c].sustain) 
+	  song->voice[i].status = VOICE_SUSTAINED;
+	else
+	  finish_note(song, i);
+      }
+}
+
+/* Process the All Sounds Off event */
+static void all_sounds_off(MidiSong *song)
+{
+  int i = song->voices;
+  int c = song->current_event->channel;
+
+  while (i--)
+    if (song->voice[i].channel == c && 
+	song->voice[i].status != VOICE_FREE &&
+	song->voice[i].status != VOICE_DIE)
+      {
+	kill_note(song, i);
+      }
+}
+
+static void adjust_pressure(MidiSong *song)
+{
+  MidiEvent *e = song->current_event;
+  int i = song->voices;
+  
+  while (i--)
+    if (song->voice[i].status == VOICE_ON &&
+	song->voice[i].channel == e->channel &&
+	song->voice[i].note == e->a)
+      {
+	song->voice[i].velocity = e->b;
+	recompute_amp(song, i);
+	apply_envelope_to_amp(song, i);
+	return;
+      }
+}
+
+static void drop_sustain(MidiSong *song)
+{
+  int i = song->voices;
+  int c = song->current_event->channel;
+
+  while (i--)
+    if (song->voice[i].status == VOICE_SUSTAINED && song->voice[i].channel == c)
+      finish_note(song, i);
+}
+
+static void adjust_pitchbend(MidiSong *song)
+{
+  int c = song->current_event->channel;
+  int i = song->voices;
+  
+  while (i--)
+    if (song->voice[i].status != VOICE_FREE && song->voice[i].channel == c)
+      {
+	recompute_freq(song, i);
+      }
+}
+
+static void adjust_volume(MidiSong *song)
+{
+  int c = song->current_event->channel;
+  int i = song->voices;
+
+  while (i--)
+    if (song->voice[i].channel == c &&
+	(song->voice[i].status==VOICE_ON || song->voice[i].status==VOICE_SUSTAINED))
+      {
+	recompute_amp(song, i);
+	apply_envelope_to_amp(song, i);
+      }
+}
+
+static void seek_forward(MidiSong *song, Sint32 until_time)
+{
+  reset_voices(song);
+  while (song->current_event->time < until_time)
+    {
+      switch(song->current_event->type)
+	{
+	  /* All notes stay off. Just handle the parameter changes. */
+
+	case ME_PITCH_SENS:
+	  song->channel[song->current_event->channel].pitchsens =
+	    song->current_event->a;
+	  song->channel[song->current_event->channel].pitchfactor = 0;
+	  break;
+	  
+	case ME_PITCHWHEEL:
+	  song->channel[song->current_event->channel].pitchbend =
+	    song->current_event->a + song->current_event->b * 128;
+	  song->channel[song->current_event->channel].pitchfactor = 0;
+	  break;
+	  
+	case ME_MAINVOLUME:
+	  song->channel[song->current_event->channel].volume =
+	    song->current_event->a;
+	  break;
+	  
+	case ME_PAN:
+	  song->channel[song->current_event->channel].panning =
+	    song->current_event->a;
+	  break;
+	      
+	case ME_EXPRESSION:
+	  song->channel[song->current_event->channel].expression =
+	    song->current_event->a;
+	  break;
+	  
+	case ME_PROGRAM:
+	  if (ISDRUMCHANNEL(song, song->current_event->channel))
+	    /* Change drum set */
+	    song->channel[song->current_event->channel].bank =
+	      song->current_event->a;
+	  else
+	    song->channel[song->current_event->channel].program =
+	      song->current_event->a;
+	  break;
+
+	case ME_SUSTAIN:
+	  song->channel[song->current_event->channel].sustain =
+	    song->current_event->a;
+	  break;
+
+	case ME_RESET_CONTROLLERS:
+	  reset_controllers(song, song->current_event->channel);
+	  break;
+	      
+	case ME_TONE_BANK:
+	  song->channel[song->current_event->channel].bank =
+	    song->current_event->a;
+	  break;
+	  
+	case ME_EOT:
+	  song->current_sample = song->current_event->time;
+	  return;
+	}
+      song->current_event++;
+    }
+  /*song->current_sample=song->current_event->time;*/
+  if (song->current_event != song->events)
+    song->current_event--;
+  song->current_sample=until_time;
+}
+
+static void skip_to(MidiSong *song, Sint32 until_time)
+{
+  if (song->current_sample > until_time)
+    song->current_sample = 0;
+
+  reset_midi(song);
+  song->buffered_count = 0;
+  song->buffer_pointer = song->common_buffer;
+  song->current_event = song->events;
+  
+  if (until_time)
+    seek_forward(song, until_time);
+}
+
+static void do_compute_data(MidiSong *song, Sint32 count)
+{
+  int i;
+  memset(song->buffer_pointer, 0, 
+	 (song->encoding & PE_MONO) ? (count * 4) : (count * 8));
+  for (i = 0; i < song->voices; i++)
+    {
+      if(song->voice[i].status != VOICE_FREE)
+	mix_voice(song, song->buffer_pointer, i, count);
+    }
+  song->current_sample += count;
+}
+
+/* count=0 means flush remaining buffered data to output device, then
+   flush the device itself */
+static void compute_data(MidiSong *song, void *stream, Sint32 count)
+{
+  int channels;
+
+  if ( song->encoding & PE_MONO )
+    channels = 1;
+  else
+    channels = 2;
+
+  if (!count)
+    {
+      if (song->buffered_count)
+          song->write(stream, song->common_buffer, channels * song->buffered_count);
+      song->buffer_pointer = song->common_buffer;
+      song->buffered_count = 0;
+      return;
+    }
+
+  while ((count + song->buffered_count) >= song->buffer_size)
+    {
+      do_compute_data(song, song->buffer_size - song->buffered_count);
+      count -= song->buffer_size - song->buffered_count;
+      song->write(stream, song->common_buffer, channels * song->buffer_size);
+      song->buffer_pointer = song->common_buffer;
+      song->buffered_count = 0;
+    }
+  if (count>0)
+    {
+      do_compute_data(song, count);
+      song->buffered_count += count;
+      song->buffer_pointer += (song->encoding & PE_MONO) ? count : count*2;
+    }
+}
+
+void Timidity_Start(MidiSong *song)
+{
+  song->playing = 1;
+  adjust_amplification(song);
+  skip_to(song, 0);
+}
+
+int Timidity_PlaySome(MidiSong *song, void *stream, Sint32 len)
+{
+  Sint32 start_sample, end_sample, samples;
+  int bytes_per_sample;
+
+  if (!song->playing)
+    return 0;
+  
+  bytes_per_sample =
+        ((song->encoding & PE_MONO) ? 1 : 2)
+      * ((song->encoding & PE_16BIT) ? 2 : 1);
+  samples = len / bytes_per_sample;
+  
+  start_sample = song->current_sample;
+  end_sample = song->current_sample+samples;
+  while ( song->current_sample < end_sample ) {
+    /* Handle all events that should happen at this time */
+    while (song->current_event->time <= song->current_sample) {
+      switch(song->current_event->type) {
+
+        /* Effects affecting a single note */
+
+        case ME_NOTEON:
+          if (!(song->current_event->b)) /* Velocity 0? */
+            note_off(song);
+          else
+            note_on(song);
+          break;
+  
+        case ME_NOTEOFF:
+          note_off(song);
+          break;
+  
+        case ME_KEYPRESSURE:
+          adjust_pressure(song);
+          break;
+  
+          /* Effects affecting a single channel */
+  
+        case ME_PITCH_SENS:
+          song->channel[song->current_event->channel].pitchsens =
+	    song->current_event->a;
+          song->channel[song->current_event->channel].pitchfactor = 0;
+          break;
+          
+        case ME_PITCHWHEEL:
+          song->channel[song->current_event->channel].pitchbend =
+            song->current_event->a + song->current_event->b * 128;
+          song->channel[song->current_event->channel].pitchfactor = 0;
+          /* Adjust pitch for notes already playing */
+          adjust_pitchbend(song);
+          break;
+          
+        case ME_MAINVOLUME:
+          song->channel[song->current_event->channel].volume =
+	    song->current_event->a;
+          adjust_volume(song);
+          break;
+          
+        case ME_PAN:
+          song->channel[song->current_event->channel].panning =
+	    song->current_event->a;
+          break;
+          
+        case ME_EXPRESSION:
+          song->channel[song->current_event->channel].expression =
+	    song->current_event->a;
+          adjust_volume(song);
+          break;
+  
+        case ME_PROGRAM:
+          if (ISDRUMCHANNEL(song, song->current_event->channel)) {
+            /* Change drum set */
+            song->channel[song->current_event->channel].bank =
+	      song->current_event->a;
+          }
+          else
+            song->channel[song->current_event->channel].program =
+	      song->current_event->a;
+          break;
+  
+        case ME_SUSTAIN:
+          song->channel[song->current_event->channel].sustain =
+	    song->current_event->a;
+          if (!song->current_event->a)
+            drop_sustain(song);
+          break;
+          
+        case ME_RESET_CONTROLLERS:
+          reset_controllers(song, song->current_event->channel);
+          break;
+  
+        case ME_ALL_NOTES_OFF:
+          all_notes_off(song);
+          break;
+          
+        case ME_ALL_SOUNDS_OFF:
+          all_sounds_off(song);
+          break;
+          
+        case ME_TONE_BANK:
+          song->channel[song->current_event->channel].bank =
+	    song->current_event->a;
+          break;
+  
+        case ME_EOT:
+          /* Give the last notes a couple of seconds to decay  */
+          SNDDBG(("Playing time: ~%d seconds\n",
+		  song->current_sample/song->rate+2));
+          SNDDBG(("Notes cut: %d\n", song->cut_notes));
+          SNDDBG(("Notes lost totally: %d\n", song->lost_notes));
+	  song->playing = 0;
+          return (song->current_sample - start_sample) * bytes_per_sample;
+        }
+      song->current_event++;
+    }
+    if (song->current_event->time > end_sample)
+      compute_data(song, stream, end_sample-song->current_sample);
+    else
+      compute_data(song, stream, song->current_event->time-song->current_sample);
+  }
+  return samples * bytes_per_sample;
+}
+
+void Timidity_SetVolume(MidiSong *song, int volume)
+{
+  int i;
+  if (volume > MAX_AMPLIFICATION)
+    song->amplification = MAX_AMPLIFICATION;
+  else
+  if (volume < 0)
+    song->amplification = 0;
+  else
+    song->amplification = volume;
+  adjust_amplification(song);
+  for (i = 0; i < song->voices; i++)
+    if (song->voice[i].status != VOICE_FREE)
+      {
+        recompute_amp(song, i);
+        apply_envelope_to_amp(song, i);
+      }
+}