Java
Ce programme convertit une tablature au format WAV 16 bits.
Tout d'abord, j'ai écrit tout un tas de code d'analyse de tablatures. Je ne sais pas si mon analyse est entièrement correcte, mais je pense que ça va. En outre, il pourrait utiliser plus de validation pour les données.
Après cela, j'ai créé le code pour générer l'audio. Chaque chaîne est générée séparément. Le programme enregistre la fréquence, l'amplitude et la phase actuelles. Il génère ensuite 10 harmoniques pour la fréquence avec des amplitudes relatives composées et les additionne. Enfin, les chaînes sont combinées et le résultat est normalisé. Le résultat est enregistré en audio WAV, que j'ai choisi pour son format ultra-simple (pas de librairies utilisées).
Il "supporte" hammering ( h) et pulling ( p) en les ignorant car je n'ai vraiment pas eu le temps de les faire sonner trop différemment. Le résultat sonne un peu comme une guitare, cependant (passé quelques heures à analyser le spectre de ma guitare dans Audacity).
En outre, il prend en charge la flexion ( b), la libération ( r) et le glissement ( /et \, interchangeables). xest implémenté comme coupant la chaîne.
Vous pouvez essayer de modifier les constantes au début du code. Un abaissement particulièrement silenceRateconduit souvent à une meilleure qualité.
Exemples de résultats
Le code
Je veux avertir les débutants Java: n'essayez pas d'apprendre quoi que ce soit de ce code, il est terriblement écrit. De plus, il a été écrit rapidement et en 2 sessions et il n'était pas destiné à être utilisé à nouveau donc il n'a aucun commentaire. (Pourrait en ajouter plus tard: P)
import java.io.*;
import java.util.*;
public class TablatureSong {
public static final int sampleRate = 44100;
public static final double silenceRate = .4;
public static final int harmonies = 10;
public static final double harmonyMultiplier = 0.3;
public static final double bendDuration = 0.25;
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
System.out.println("Output file:");
String outfile = in.nextLine();
System.out.println("Enter tablature:");
Tab tab = parseTablature(in);
System.out.println("Enter tempo:");
int tempo = in.nextInt();
in.close();
int samples = (int) (60.0 / tempo * tab.length * sampleRate);
double[][] strings = new double[6][];
for (int i = 0; i < 6; i++) {
System.out.printf("Generating string %d/6...\n", i + 1);
strings[i] = generateString(tab.actions.get(i), tempo, samples);
}
System.out.println("Combining...");
double[] combined = new double[samples];
for (int i = 0; i < samples; i++)
for (int j = 0; j < 6; j++)
combined[i] += strings[j][i];
System.out.println("Normalizing...");
double max = 0;
for (int i = 0; i < combined.length; i++)
max = Math.max(max, combined[i]);
for (int i = 0; i < combined.length; i++)
combined[i] = Math.min(1, combined[i] / max);
System.out.println("Writing file...");
writeWaveFile(combined, outfile);
System.out.println("Done");
}
private static double[] generateString(List<Action> actions, int tempo, int samples) {
double[] harmonyPowers = new double[harmonies];
for (int harmony = 0; harmony < harmonyPowers.length; harmony++) {
if (Integer.toBinaryString(harmony).replaceAll("[^1]", "").length() == 1)
harmonyPowers[harmony] = 2 * Math.pow(harmonyMultiplier, harmony);
else
harmonyPowers[harmony] = Math.pow(harmonyMultiplier, harmony);
}
double actualSilenceRate = Math.pow(silenceRate, 1.0 / sampleRate);
double[] data = new double[samples];
double phase = 0.0, amplitude = 0.0;
double slidePos = 0.0, slideLength = 0.0;
double startFreq = 0.0, endFreq = 0.0, thisFreq = 440.0;
double bendModifier = 0.0;
Iterator<Action> iterator = actions.iterator();
Action next = iterator.hasNext() ? iterator.next() : new Action(Action.Type.NONE, Integer.MAX_VALUE);
for (int sample = 0; sample < samples; sample++) {
while (sample >= toSamples(next.startTime, tempo)) {
switch (next.type) {
case NONE:
break;
case NOTE:
amplitude = 1.0;
startFreq = endFreq = thisFreq = next.value;
bendModifier = 0.0;
slidePos = 0.0;
slideLength = 0;
break;
case BEND:
startFreq = addHalfSteps(thisFreq, bendModifier);
bendModifier = next.value;
slidePos = 0.0;
slideLength = toSamples(bendDuration);
endFreq = addHalfSteps(thisFreq, bendModifier);
break;
case SLIDE:
slidePos = 0.0;
slideLength = toSamples(next.endTime - next.startTime, tempo);
startFreq = thisFreq;
endFreq = thisFreq = next.value;
break;
case MUTE:
amplitude = 0.0;
break;
}
next = iterator.hasNext() ? iterator.next() : new Action(Action.Type.NONE, Integer.MAX_VALUE);
}
double currentFreq;
if (slidePos >= slideLength || slideLength == 0)
currentFreq = endFreq;
else
currentFreq = startFreq + (endFreq - startFreq) * (slidePos / slideLength);
data[sample] = 0.0;
for (int harmony = 1; harmony <= harmonyPowers.length; harmony++) {
double phaseVolume = Math.sin(2 * Math.PI * phase * harmony);
data[sample] += phaseVolume * harmonyPowers[harmony - 1];
}
data[sample] *= amplitude;
amplitude *= actualSilenceRate;
phase += currentFreq / sampleRate;
slidePos++;
}
return data;
}
private static int toSamples(double seconds) {
return (int) (sampleRate * seconds);
}
private static int toSamples(double beats, int tempo) {
return (int) (sampleRate * beats * 60.0 / tempo);
}
private static void writeWaveFile(double[] data, String outfile) {
try (OutputStream out = new FileOutputStream(new File(outfile))) {
out.write(new byte[] { 0x52, 0x49, 0x46, 0x46 }); // Header: "RIFF"
write32Bit(out, 44 + 2 * data.length, false); // Total size
out.write(new byte[] { 0x57, 0x41, 0x56, 0x45 }); // Header: "WAVE"
out.write(new byte[] { 0x66, 0x6d, 0x74, 0x20 }); // Header: "fmt "
write32Bit(out, 16, false); // Subchunk1Size: 16
write16Bit(out, 1, false); // Format: 1 (PCM)
write16Bit(out, 1, false); // Channels: 1
write32Bit(out, 44100, false); // Sample rate: 44100
write32Bit(out, 44100 * 1 * 2, false); // Sample rate * channels *
// bytes per sample
write16Bit(out, 1 * 2, false); // Channels * bytes per sample
write16Bit(out, 16, false); // Bits per sample
out.write(new byte[] { 0x64, 0x61, 0x74, 0x61 }); // Header: "data"
write32Bit(out, 2 * data.length, false); // Data size
for (int i = 0; i < data.length; i++) {
write16Bit(out, (int) (data[i] * Short.MAX_VALUE), false); // Data
}
out.close();
} catch (IOException e) {
e.printStackTrace();
}
}
private static void write16Bit(OutputStream stream, int val, boolean bigEndian) throws IOException {
int a = (val & 0xFF00) >> 8;
int b = val & 0xFF;
if (bigEndian) {
stream.write(a);
stream.write(b);
} else {
stream.write(b);
stream.write(a);
}
}
private static void write32Bit(OutputStream stream, int val, boolean bigEndian) throws IOException {
int a = (val & 0xFF000000) >> 24;
int b = (val & 0xFF0000) >> 16;
int c = (val & 0xFF00) >> 8;
int d = val & 0xFF;
if (bigEndian) {
stream.write(a);
stream.write(b);
stream.write(c);
stream.write(d);
} else {
stream.write(d);
stream.write(c);
stream.write(b);
stream.write(a);
}
}
private static double[] strings = new double[] { 82.41, 110.00, 146.83, 196.00, 246.94, 329.63 };
private static Tab parseTablature(Scanner in) {
String[] lines = new String[6];
List<List<Action>> result = new ArrayList<>();
int longest = 0;
for (int i = 0; i < 6; i++) {
lines[i] = in.nextLine().trim().substring(2);
longest = Math.max(longest, lines[i].length());
}
int skipped = 0;
for (int i = 0; i < 6; i++) {
StringIterator iterator = new StringIterator(lines[i]);
List<Action> actions = new ArrayList<Action>();
while (iterator.index() < longest) {
if (iterator.get() < '0' || iterator.get() > '9') {
switch (iterator.get()) {
case 'b':
actions.add(new Action(Action.Type.BEND, 1, iterator.index(), iterator.index()));
iterator.next();
break;
case 'r':
actions.add(new Action(Action.Type.BEND, 0, iterator.index(), iterator.index()));
iterator.next();
break;
case '/':
case '\\':
int startTime = iterator.index();
iterator.findNumber();
int endTime = iterator.index();
int endFret = iterator.readNumber();
actions.add(new Action(Action.Type.SLIDE, addHalfSteps(strings[5 - i], endFret), startTime,
endTime));
break;
case 'x':
actions.add(new Action(Action.Type.MUTE, iterator.index()));
iterator.next();
break;
case '|':
iterator.skip(1);
iterator.next();
break;
case 'h':
case 'p':
case '-':
iterator.next();
break;
default:
throw new RuntimeException(String.format("Unrecognized character: '%c'", iterator.get()));
}
} else {
StringBuilder number = new StringBuilder();
int startIndex = iterator.index();
while (iterator.get() >= '0' && iterator.get() <= '9') {
number.append(iterator.get());
iterator.next();
}
int fret = Integer.parseInt(number.toString());
double freq = addHalfSteps(strings[5 - i], fret);
actions.add(new Action(Action.Type.NOTE, freq, startIndex, startIndex));
}
}
result.add(actions);
skipped = iterator.skipped();
}
return new Tab(result, longest - skipped);
}
private static double addHalfSteps(double freq, double halfSteps) {
return freq * Math.pow(2, halfSteps / 12.0);
}
}
class StringIterator {
private String string;
private int index, skipped;
public StringIterator(String string) {
this.string = string;
index = 0;
skipped = 0;
}
public boolean hasNext() {
return index < string.length() - 1;
}
public void next() {
index++;
}
public void skip(int length) {
skipped += length;
}
public char get() {
if (index < string.length())
return string.charAt(index);
return '-';
}
public int index() {
return index - skipped;
}
public int skipped() {
return skipped;
}
public boolean findNumber() {
while (hasNext() && (get() < '0' || get() > '9'))
next();
return get() >= '0' && get() <= '9';
}
public int readNumber() {
StringBuilder number = new StringBuilder();
while (get() >= '0' && get() <= '9') {
number.append(get());
next();
}
return Integer.parseInt(number.toString());
}
}
class Action {
public static enum Type {
NONE, NOTE, BEND, SLIDE, MUTE;
}
public Type type;
public double value;
public int startTime, endTime;
public Action(Type type, int time) {
this(type, time, time);
}
public Action(Type type, int startTime, int endTime) {
this(type, 0, startTime, endTime);
}
public Action(Type type, double value, int startTime, int endTime) {
this.type = type;
this.value = value;
this.startTime = startTime;
this.endTime = endTime;
}
}
class Tab {
public List<List<Action>> actions;
public int length;
public Tab(List<List<Action>> actions, int length) {
this.actions = actions;
this.length = length;
}
}