playmidi.c

MIDI解码程序(用VC编写)

							(bend_fine[-tmp >> 5 & 0xff]
							* bend_coarse[-tmp >> 13 & 0x7f]);
			}
			voice[v].frequency =
					voice[v].orig_frequency * channel[ch].pitchfactor;
			if (voice[v].frequency != voice[v].orig_frequency)
				voice[v].cache = NULL;
		}
	} else {	/* Portamento */
		pb -= 0x2000;
		tmp = pb * channel[ch].rpnmap[RPN_ADDR_0000]
				+ (voice[v].porta_pb << 5) + tuning;
		if (tmp >= 0)
			pf = bend_fine[tmp >> 5 & 0xff]
					* bend_coarse[tmp >> 13 & 0x7f];
		else
			pf = 1.0 / (bend_fine[-tmp >> 5 & 0xff]
					* bend_coarse[-tmp >> 13 & 0x7f]);
		voice[v].frequency = voice[v].orig_frequency * pf;
		voice[v].cache = NULL;
	}
	root_freq = voice[v].sample->root_freq;
	a = TIM_FSCALE(((double) voice[v].sample->sample_rate
			* ((double)voice[v].frequency + channel[ch].pitch_offset_fine))
			/ (root_freq * play_mode->rate), FRACTION_BITS) + 0.5;
	/* need to preserve the loop direction */
	voice[v].sample_increment = (voice[v].sample_increment >= 0) ? a : -a;
#ifdef ABORT_AT_FATAL
	if (voice[v].sample_increment == 0) {
		fprintf(stderr, "Invalid sample increment a=%e %ld %ld %ld %ld%s\n",
				(double)a, (long) voice[v].sample->sample_rate,
				(long) voice[v].frequency, (long) voice[v].sample->root_freq,
				(long) play_mode->rate, (voice[v].cache) ? " (Cached)" : "");
		abort();
	}
#endif	/* ABORT_AT_FATAL */
}

static int32 calc_velocity(int32 ch,int32 vel)
{
	int32 velocity;
	velocity = channel[ch].velocity_sense_depth * vel / 64 + (channel[ch].velocity_sense_offset - 64) * 2;
	if(velocity > 127) {velocity = 127;}
	return velocity;
}

static void recompute_voice_tremolo(int v)
{
	Voice *vp = &(voice[v]);
	int ch = vp->channel;
	int32 depth = vp->sample->tremolo_depth;
	depth += get_midi_controller_amp_depth(&(channel[ch].mod))
		+ get_midi_controller_amp_depth(&(channel[ch].bend))
		+ get_midi_controller_amp_depth(&(channel[ch].caf))
		+ get_midi_controller_amp_depth(&(channel[ch].paf))
		+ get_midi_controller_amp_depth(&(channel[ch].cc1))
		+ get_midi_controller_amp_depth(&(channel[ch].cc2));
	if(depth > 256) {depth = 256;}
	vp->tremolo_depth = depth;
}

static void recompute_amp(int v)
{
	FLOAT_T tempamp;
	int ch = voice[v].channel;

	/* master_volume and sample->volume are percentages, used to scale
	 *  amplitude directly, NOT perceived volume
	 *
	 * all other MIDI volumes are linear in perceived volume, 0-127
	 * use a lookup table for the non-linear scalings
	 */
	if (opt_user_volume_curve) {
	tempamp = master_volume *
		   voice[v].sample->volume *
		   user_vol_table[calc_velocity(ch, voice[v].velocity)] *
		   user_vol_table[channel[ch].volume] *
		   user_vol_table[channel[ch].expression]; /* 21 bits */
	} else if (play_system_mode == GM2_SYSTEM_MODE) {
	tempamp = master_volume *
		  voice[v].sample->volume *
		  gm2_vol_table[calc_velocity(ch, voice[v].velocity)] *	/* velocity: not in GM2 standard */
		  gm2_vol_table[channel[ch].volume] *
		  gm2_vol_table[channel[ch].expression]; /* 21 bits */
	} else if(play_system_mode == GS_SYSTEM_MODE) {	/* use measured curve */ 
	tempamp = master_volume *
		   voice[v].sample->volume *
		   sc_vel_table[calc_velocity(ch, voice[v].velocity)] *
		   sc_vol_table[channel[ch].volume] *
		   sc_vol_table[channel[ch].expression]; /* 21 bits */
	} else if (IS_CURRENT_MOD_FILE) {	/* use linear curve */
	tempamp = master_volume *
		  voice[v].sample->volume *
		  calc_velocity(ch, voice[v].velocity) *
		  channel[ch].volume *
		  channel[ch].expression; /* 21 bits */
	} else {	/* use generic exponential curve */
	tempamp = master_volume *
		  voice[v].sample->volume *
		  perceived_vol_table[calc_velocity(ch, voice[v].velocity)] *
		  perceived_vol_table[channel[ch].volume] *
		  perceived_vol_table[channel[ch].expression]; /* 21 bits */
	}

	/* every digital effect increases amplitude,
	 * so that it must be reduced in advance.
	 */
	if (! (play_mode->encoding & PE_MONO)
	    && (opt_reverb_control || opt_chorus_control || opt_delay_control
		|| (opt_eq_control && (eq_status_gs.low_gain != 0x40
				       || eq_status_gs.high_gain != 0x40))
		|| opt_insertion_effect))
		tempamp *= 1.35f * 0.55f;
	else
		tempamp *= 1.35f;

	/* NRPN - drum instrument tva level */
	if(ISDRUMCHANNEL(ch)) {
		if(channel[ch].drums[voice[v].note] != NULL) {
			tempamp *= channel[ch].drums[voice[v].note]->drum_level;
		}
		tempamp *= (double)opt_drum_power * 0.01f;	/* global drum power */
	}

	/* MIDI controllers amplitude control */
	if(opt_channel_pressure) {
		tempamp *= get_midi_controller_amp(&(channel[ch].mod))
			* get_midi_controller_amp(&(channel[ch].bend))
			* get_midi_controller_amp(&(channel[ch].caf))
			* get_midi_controller_amp(&(channel[ch].paf))
			* get_midi_controller_amp(&(channel[ch].cc1))
			* get_midi_controller_amp(&(channel[ch].cc2));
		recompute_voice_tremolo(v);
	}

	if (voice[v].fc.type != 0) {
		tempamp *= voice[v].fc.gain;	/* filter gain */
	}

	/* applying panning to amplitude */
	if(!(play_mode->encoding & PE_MONO))
    	{
		if(voice[v].panning == 64)
		{
			voice[v].panned = PANNED_CENTER;
			voice[v].left_amp = voice[v].right_amp = TIM_FSCALENEG(tempamp * pan_table[64], 27);
		}
		else if (voice[v].panning < 2)
		{
			voice[v].panned = PANNED_LEFT;
			voice[v].left_amp = TIM_FSCALENEG(tempamp, 20);
			voice[v].right_amp = 0;
		}
		else if(voice[v].panning == 127)
		{
#ifdef SMOOTH_MIXING
			if(voice[v].panned == PANNED_MYSTERY) {
				voice[v].old_left_mix = voice[v].old_right_mix;
				voice[v].old_right_mix = 0;
			}
#endif
			voice[v].panned = PANNED_RIGHT;
			voice[v].left_amp =  TIM_FSCALENEG(tempamp, 20);
			voice[v].right_amp = 0;
		}
		else
		{
#ifdef SMOOTH_MIXING
			if(voice[v].panned == PANNED_RIGHT) {
				voice[v].old_right_mix = voice[v].old_left_mix;
				voice[v].old_left_mix = 0;
			}
#endif
			voice[v].panned = PANNED_MYSTERY;
			voice[v].left_amp = TIM_FSCALENEG(tempamp * pan_table[128 - voice[v].panning], 27);
			voice[v].right_amp = TIM_FSCALENEG(tempamp * pan_table[voice[v].panning], 27);
		}
    	}
    	else
    	{
		voice[v].panned = PANNED_CENTER;
		voice[v].left_amp = TIM_FSCALENEG(tempamp, 21);
    	}
}

#define RESONANCE_COEFF 0.2393

void recompute_channel_filter(int ch, int note)
{
	double coef = 1.0f, reso = 0;

	if(channel[ch].special_sample > 0) {return;}

	/* Soft Pedal */
	if(channel[ch].soft_pedal != 0) {
		if(note > 49) {	/* tre corde */
			coef *= 1.0 - 0.20 * ((double)channel[ch].soft_pedal) / 127.0f;
		} else {	/* una corda (due corde) */
			coef *= 1.0 - 0.25 * ((double)channel[ch].soft_pedal) / 127.0f;
		}
	}

	if(!ISDRUMCHANNEL(ch)) {
		/* NRPN Filter Cutoff */
		coef *= pow(1.26, (double)(channel[ch].param_cutoff_freq) / 8.0f);
		/* NRPN Resonance */
		reso = (double)channel[ch].param_resonance * RESONANCE_COEFF;
	}

	channel[ch].cutoff_freq_coef = coef;
	channel[ch].resonance_dB = reso;
}

void init_voice_filter(int i)
{
  memset(&(voice[i].fc), 0, sizeof(FilterCoefficients));
  if(opt_lpf_def && voice[i].sample->cutoff_freq) {
	  voice[i].fc.orig_freq = voice[i].sample->cutoff_freq;
	  voice[i].fc.orig_reso_dB = (double)voice[i].sample->resonance / 10.0f - 3.01f;
	  if (voice[i].fc.orig_reso_dB < 0.0f) {voice[i].fc.orig_reso_dB = 0.0f;}
	  if (opt_lpf_def == 2) {
		  voice[i].fc.gain = 1.0;
		  voice[i].fc.type = 2;
	  } else if(opt_lpf_def == 1) {
		  voice[i].fc.gain = pow(10.0f, -voice[i].fc.orig_reso_dB / 2.0f / 20.0f);
		  voice[i].fc.type = 1;
	  }
	  voice[i].fc.start_flag = 0;
  } else {
	  voice[i].fc.type = 0;
  }
}

#define CHAMBERLIN_RESONANCE_MAX 24.0

void recompute_voice_filter(int v)
{
	int ch = voice[v].channel, note = voice[v].note;
	double coef = 1.0, reso = 0, cent = 0, depth_cent = 0, freq;
	FilterCoefficients *fc = &(voice[v].fc);
	Sample *sp = (Sample *) &voice[v].sample;

	if(fc->type == 0) {return;}
	coef = channel[ch].cutoff_freq_coef;

	if(ISDRUMCHANNEL(ch) && channel[ch].drums[note] != NULL) {
		/* NRPN Drum Instrument Filter Cutoff */
		coef *= pow(1.26, (double)(channel[ch].drums[note]->drum_cutoff_freq) / 8.0f);
		/* NRPN Drum Instrument Filter Resonance */
		reso += (double)channel[ch].drums[note]->drum_resonance * RESONANCE_COEFF;
	}

	/* MIDI controllers filter cutoff control and LFO filter depth */
	if(opt_channel_pressure) {
		cent += get_midi_controller_filter_cutoff(&(channel[ch].mod))
			+ get_midi_controller_filter_cutoff(&(channel[ch].bend))
			+ get_midi_controller_filter_cutoff(&(channel[ch].caf))
			+ get_midi_controller_filter_cutoff(&(channel[ch].paf))
			+ get_midi_controller_filter_cutoff(&(channel[ch].cc1))
			+ get_midi_controller_filter_cutoff(&(channel[ch].cc2));
		depth_cent += get_midi_controller_filter_depth(&(channel[ch].mod))
			+ get_midi_controller_filter_depth(&(channel[ch].bend))
			+ get_midi_controller_filter_depth(&(channel[ch].caf))
			+ get_midi_controller_filter_depth(&(channel[ch].paf))
			+ get_midi_controller_filter_depth(&(channel[ch].cc1))
			+ get_midi_controller_filter_depth(&(channel[ch].cc2));
	}

	if(sp->vel_to_fc) {	/* velocity to filter cutoff frequency */
		if(voice[v].velocity > sp->vel_to_fc_threshold)
			cent += sp->vel_to_fc * (double)(127 - voice[v].velocity) / 127.0f;
		else
			coef += sp->vel_to_fc * (double)(127 - sp->vel_to_fc_threshold) / 127.0f;
	}
	if(sp->vel_to_resonance) {	/* velocity to filter resonance */
		reso += (double)voice[v].velocity * sp->vel_to_resonance / 127.0f / 10.0f;
	}
	if(sp->key_to_fc) {	/* filter cutoff key-follow */
		cent += sp->key_to_fc * (double)(voice[v].note - sp->key_to_fc_bpo);
	}

	if(opt_modulation_envelope) {
		if(voice[v].sample->tremolo_to_fc + (int16)depth_cent) {
			cent += ((double)voice[v].sample->tremolo_to_fc + depth_cent) * lookup_triangular(voice[v].tremolo_phase >> RATE_SHIFT);
		}
		if(voice[v].sample->modenv_to_fc) {
			cent += (double)voice[v].sample->modenv_to_fc * voice[v].last_modenv_volume;
		}
	}

	if(cent != 0) {coef *= pow(2.0, cent / 1200.0f);}

	freq = (double)fc->orig_freq * coef;

	if (freq > play_mode->rate / 2) {freq = play_mode->rate / 2;}
	else if(freq < 5) {freq = 5;}
	else if(freq > 20000) {freq = 20000;}
	fc->freq = (int32)freq;

	fc->reso_dB = fc->orig_reso_dB + channel[ch].resonance_dB + reso;
	if(fc->reso_dB < 0.0f) {fc->reso_dB = 0.0f;}
	else if(fc->reso_dB > 96.0f) {fc->reso_dB = 96.0f;}

	if(fc->type == 1) {	/* Chamberlin filter */
		if(fc->freq > play_mode->rate / 6) {
			if (fc->start_flag == 0) {fc->type = 0;}	/* turn off. */ 
			else {fc->freq = play_mode->rate / 6;}
		}
		if(fc->reso_dB > CHAMBERLIN_RESONANCE_MAX) {fc->reso_dB = CHAMBERLIN_RESONANCE_MAX;}
	} else if(fc->type == 2) {	/* Moog VCF */
		if(fc->reso_dB > fc->orig_reso_dB / 2) {
			fc->gain = pow(10.0f, (fc->reso_dB - fc->orig_reso_dB / 2) / 20.0f);
		}
	}
	fc->start_flag = 1;	/* filter is started. */
}

float calc_drum_tva_level(int ch, int note, int level)
{
	int def_level, nbank, nprog;
	ToneBank *bank;

	if(channel[ch].special_sample > 0) {return 1.0;}

	nbank = channel[ch].bank;
	nprog = note;
	instrument_map(channel[ch].mapID, &nbank, &nprog);

	if(ISDRUMCHANNEL(ch)) {
		bank = drumset[nbank];
		if(bank == NULL) {bank = drumset[0];}
	} else {
		return 1.0;
	}

	def_level = bank->tone[nprog].tva_level;

	if(def_level == -1 || def_level == 0) {def_level = 127;}
	else if(def_level > 127) {def_level = 127;}

	return (sc_drum_level_table[level] / sc_drum_level_table[def_level]);
}

static int32 calc_random_delay(int ch, int note)
{
	int nbank, nprog;
	ToneBank *bank;

	if(channel[ch].special_sample > 0) {return 0;}

	nbank = channel[ch].bank;

	if(ISDRUMCHANNEL(ch)) {
		nprog = note;
		instrument_map(channel[ch].mapID, &nbank, &nprog);
		bank = drumset[nbank];
		if (bank == NULL) {bank = drumset[0];}
	} else {
		nprog = channel[ch].program;
		if(nprog == SPECIAL_PROGRAM) {return 0;}
		instrument_map(channel[ch].mapID, &nbank, &nprog);
		bank = tonebank[nbank];
		if(bank == NULL) {bank = tonebank[0];}
	}

	if (bank->tone[nprog].rnddelay == 0) {return 0;}
	else {return (int32)((double)bank->tone[nprog].rnddelay * play_mode->rate / 1000.0
		* (get_pink_noise_light(&global_pink_noise_light) + 1.0f) * 0.5);}
}

void recompute_bank_parameter(int ch, int note)
{
	int nbank, nprog;
	ToneBank *bank;
	struct DrumParts *drum;

	if(channel[ch].special_sample > 0) {return;}

	nbank = channel[ch].bank;

	if(ISDRUMCHANNEL(ch)) {
		nprog = note;
		instrument_map(channel[ch].mapID, &nbank, &nprog);
		bank = drumset[nbank];
		if (bank == NULL) {bank = drumset[0];}
		if (channel[ch].drums[note] == NULL)
				play_midi_setup_drums(ch, note);
		drum = channel[ch].drums[note];
		if (drum->reverb_level == -1 && bank->tone[nprog].reverb_send != -1) {
			drum->reverb_level = bank->tone[nprog].reverb_send;
		}
		if (drum->chorus_level == -1 && bank->tone[nprog].chorus_send != -1) {
			drum->chorus_level = bank->tone[nprog].chorus_send;
		}
		if (drum->delay_level == -1 && bank->tone[nprog].delay_send != -1) {
			drum->delay_level = bank->tone[nprog].delay_send;
		}
	} else {
		nprog = channel[ch].program;
		if (nprog == SPECIAL_PROGRAM) {return;}
		instrument_map(channel[ch].mapID, &nbank, &nprog);
		bank = tonebank[nbank];
		if (bank == NULL) {bank = tonebank[0];}
		channel[ch].legato = bank->tone[nprog].legato;
		channel[ch].damper_mode = bank->tone[nprog].damper_mode;
		channel[ch].loop_timeout = bank->tone[nprog].loop_timeout;
	}
}

Instrument *play_midi_load_instrument(int dr, int bk, int prog)
{
	ToneBank **bank = (dr) ? drumset : tonebank;
	Instrument *ip;
	int load_success = 0;

	if (bank[bk] == NULL)
		alloc_instrument_bank(dr, bk);

	if (bank[bk]->tone[prog].name) {
		/* Instrument is found. */
		if ((ip = bank[bk]->tone[prog].instrument) == MAGIC_LOAD_INSTRUMENT
#ifndef SUPPRESS_CHANNEL_LAYER
			|| ip == NULL	/* see also readmidi.c: groom_list(). */
#endif
		) {ip = bank[bk]->tone[prog].instrument = load_instrument(dr, bk, prog);}
		if (ip == NULL || IS_MAGIC_INSTRUMENT(ip)) {
			bank[bk]->tone[prog].instrument = MAGIC_ERROR_INSTRUMENT;
		} else {
			load_success = 1;
		}
	} else {
		/* Instrument is not found.
		   Try to load the instrument from bank 0 */
		if ((ip = bank[0]->tone[prog].instrument) == NULL
			|| ip == MAGIC_LOAD_INSTRUMENT)
			ip = bank[0]->tone[prog].instrument = load_instrument(dr, 0, prog);
		if (ip == NULL || IS_MAGIC_INSTRUMENT(ip)) {
			bank[0]->tone[prog].instrument = MAGIC_ERROR_INSTRUMENT;
		} else {
			copy_tone_bank_element(&bank[bk]->tone[prog], &bank[0]->tone[prog]);
			bank[bk]->tone[prog].instrument = ip;
			load_success = 1;
		}
	}

	if (load_success)
		aq_add(NULL, 0);	/* Update software buffer */

	if (ip == MAGIC_ERROR_INSTRUMENT)