Java
Dieses Programm konvertiert eine Tabulatur in ein 16-Bit-WAV-Format.
Erstens habe ich eine ganze Reihe von Tabulatur-Parsing-Code geschrieben. Ich bin nicht sicher, ob meine Analyse vollständig korrekt ist, aber ich denke, es ist in Ordnung. Es könnte auch mehr Validierung für Daten gebrauchen.
Danach habe ich den Code erstellt, um das Audio zu generieren. Jeder String wird separat generiert. Das Programm verfolgt die aktuelle Frequenz, Amplitude und Phase. Es werden dann 10 Obertöne für die Frequenz mit erfundenen relativen Amplituden erzeugt und addiert. Schließlich werden die Zeichenfolgen kombiniert und das Ergebnis wird normalisiert. Das Ergebnis wird als WAV-Audio gespeichert, das ich für sein ultra-einfaches Format ausgewählt habe (keine Bibliotheken verwendet).
Es "unterstützt" das Hämmern ( h) und Ziehen ( p), indem es sie ignoriert, da ich wirklich keine Zeit hatte, sie zu unterschiedlich klingen zu lassen. Das Ergebnis klingt allerdings ein bisschen wie eine Gitarre (verbrachte einige Stunden damit, meine Gitarre in Audacity zu analysieren).
Es unterstützt auch das Biegen ( b), Loslassen ( r) und Gleiten ( /und \austauschbar). xwird als Muting des Strings implementiert.
Sie können versuchen, die Konstanten am Anfang des Codes zu optimieren. Besonders das Absenken silenceRateführt oft zu einer besseren Qualität.
Beispielergebnisse
Der Code
Ich möchte jeden Java-Anfänger warnen: Versuchen Sie nicht , etwas aus diesem Code zu lernen, er ist schrecklich geschrieben. Außerdem wurde es schnell und in 2 Sitzungen geschrieben und sollte nie wieder verwendet werden, sodass es keine Kommentare enthält. (Könnte später hinzugefügt werden: 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;
}
}