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Ralty
2025-08-01 11:58:21 +07:00
parent 888f4135e9
commit aabfb0f3cd
1 changed files with 181 additions and 72 deletions
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source/funkin/backend/utils/AudioAnalyzer.hx
+181 -72
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@@ -24,7 +24,7 @@ class AudioAnalyzer {
if (wordSize == 2) return inline ArrayBufferIO.getInt16(buf, pos);
else if (wordSize == 3) {
var b = inline ArrayBufferIO.getUint16(buf, pos) | (buf.get(pos + 2) << 16);
if (b > 8388608) return b - 16777216;
if (b & 0x800000 != 0) return b - 0x1000000;
else return b;
}
else if (wordSize == 4) return inline ArrayBufferIO.getInt32(buf, pos);
@@ -33,7 +33,7 @@ class AudioAnalyzer {
public var sound:FlxSound;
public var buffer(default, null):AudioBuffer;
public var fftSamples(default, set):Int;
public var fftN(default, set):Int;
public var byteSize(default, null):Int;
@@ -59,11 +59,14 @@ class AudioAnalyzer {
var __sampleOutput:Array<Float>;
// fft
var __N2:Int;
var __logN:Int;
var __freqSamples:Array<Float>;
var __reverseIndices:Array<Int> = [];
var __rootReals:Array<Float> = [];
var __rootImags:Array<Float> = [];
var __factors:Array<Int> = [];
var __windows:Array<Float> = [];
var __twiddleReals:Array<Float> = [];
var __twiddleImags:Array<Float> = [];
var __freqReals:Array<Float> = [];
var __freqImags:Array<Float> = [];
@@ -74,9 +77,9 @@ class AudioAnalyzer {
* Creates an analyzer for specified FlxSound
* @param sound An FlxSound to analyze.
**/
public function new(sound:FlxSound, fftSamples = 512) {
public function new(sound:FlxSound, fftN = 2048) {
this.sound = sound;
this.fftSamples = fftSamples;
this.fftN = fftN;
__check();
}
@@ -90,23 +93,50 @@ class AudioAnalyzer {
__max.resize(buffer.channels);
}
inline function set_fftSamples(v:Int):Int {
if (fftSamples == (fftSamples = v)) return v;
var half = v >> 1, a, c;
__logN = Math.floor(Math.log(v) / Math.log(2));
__reverseIndices.resize(half);
__rootReals.resize(half);
__rootImags.resize(half);
__freqReals.resize(half);
__freqImags.resize(half);
for (i in 0...half) {
inline function set_fftN(v:Int):Int {
if (fftN == (fftN = nextPow2(v))) return fftN;
__logN = Math.floor(Math.log(fftN) / Math.log(2));
__N2 = fftN >> 1;
__freqReals.resize(fftN);
__freqImags.resize(fftN);
__reverseIndices.resize(fftN);
__windows.resize(fftN);
__twiddleReals.resize(fftN);
__twiddleImags.resize(fftN);
var f, a;
for (i in 0...fftN) {
f = i / (fftN - 1);
__windows[i] = 0.42 - 0.5 * Math.cos(Math.PI * 2 * f) + 0.08 * Math.cos(4 * Math.PI * f);
__reverseIndices[i] = __bitReverse(i);
__rootReals[i] = Math.cos(a = 2 * Math.PI * i / v);
__rootImags[i] = Math.sin(a);
__twiddleReals[i] = Math.cos(a = 2 * Math.PI * i / fftN);
__twiddleImags[i] = Math.sin(a);
}
return v;
__factors.resize(0);
var inv = fftN;
while (inv > 0) {
if (inv % 4 == 0) {
__factors.push(4);
inv >>= 2;
}
else if (inv % 2 == 0) {
__factors.push(2);
inv >>= 1;
}
else
break;
}
return fftN;
}
inline function nextPow2(x:Int):Int {
var p = 1;
while (p < x) p <<= 1;
return p;
}
inline function __bitReverse(x:Int):Int {
@@ -119,27 +149,39 @@ class AudioAnalyzer {
return y;
}
public function getLevels(startPos:Float, barCount:Int, ?levels:Array<Float>, delta = 0.0, minDb = -70.0, maxDb = -20.0):Array<Float> {
public function getLevels(startPos:Float, barCount:Int, ?levels:Array<Float>, delta = 0.0, dbRange = 50.0, minFreq = 20.0, maxFreq = 20000.0):Array<Float> {
__frequencies = getFrequencies(startPos, __frequencies);
if (levels == null) levels = [];
levels.resize(barCount);
var x1 = 0.5, i1 = 1, n = fftSamples >> 1;
var x2, i2, v;
for (i in 0...barCount) {
i2 = Math.floor(x2 = Math.pow(n, (i + 1) / barCount) - 0.5);
var logMin = Math.log(minFreq), logMax = Math.log(maxFreq);
inline function calculateScale(i:Int)
return CoolUtil.bound(Math.exp(logMin + ((logMax - logMin) * i / barCount)) * fftN / buffer.sampleRate, 0, __N2 - 1);
if (i2 < i1) v = __frequencies[i2] * (x2 - x1);
var s1 = calculateScale(0), s2;
var i1 = Math.floor(s1), i2;
var v, range;
for (i in 0...barCount) {
i2 = Math.ceil(s2 = calculateScale(i));
if ((range = s2 - s1) < 1) {
if (i2 == i1) v = __frequencies[i1] * range;
else v = (s1 + (s2 - s1) * (s1 - i1)) * range;
}
else {
v = __frequencies[i1 - 1] * (i1 - x1);
while (i1 < i2) v += __frequencies[i1++];
if (i2 < n) v += __frequencies[i2] * (x2 - i2);
v = __frequencies[i1] * (Math.ceil(s1) - i1);
while (++i1 < i2) v += __frequencies[i1];
v += __frequencies[i2] * (s2 - Math.floor(s2));
}
i1 = Math.ceil(x1 = x2);
i1 = Math.floor(s1 = s2);
if (v > 0) v = 20 * Math.log(v) / 2.302585092994046;//log(10)
else v = -200;
v = CoolUtil.bound(1 + v / dbRange, 0, 1);
v = 20 * Math.log(v * barCount / 12) / 2.302585092994046/*log(10)*/ / (maxDb - minDb);
if (delta > 0 && levels[i] > v) levels[i] -= (levels[i] - v) * delta;
else levels[i] = v;
}
@@ -149,48 +191,106 @@ class AudioAnalyzer {
/**
* Gets frequencies from an attached FlxSound from startPos with samples
* @return Output of frequencies ranging from 1 to fftSamples/2.
* @return Output of frequencies ranging from 1 to fftN/2.
**/
public function getFrequencies(startPos:Float, ?frequencies:Array<Float>):Array<Float> {
__freqSamples = getSamples(startPos, fftSamples, true, __freqSamples);
var inv = fftSamples >> 1;
for (i in 0...inv) {
__freqReals[__reverseIndices[i]] = __freqSamples[i];
__freqImags[i] = 0;
}
var h = 1, g = 0, b = 0, r = 0;
var tr, ti, i1, i2;
while (inv > 0) {
h <<= 1;
while (g < fftSamples) {
while (b < h) {
i2 = (i1 = g + b) + h;
tr = __rootReals[r] * __freqReals[i2] - __rootImags[r] * __freqImags[i2];
ti = __rootReals[r] * __freqImags[i2] + __rootImags[r] * __freqReals[i2];
__rootReals[i2] = __freqReals[i1] - tr;
__rootImags[i2] = __freqImags[i1] - ti;
__freqReals[i1] += tr;
__freqImags[i1] += ti;
b++;
r += inv;
}
b = r = 0;
g += h;
}
g = 0;
inv >>= 1;
}
__freqSamples = getSamples(startPos, fftN, true, __freqSamples);
if (frequencies == null) frequencies = [];
frequencies.resize(inv = fftSamples >> 1);
var mag;
for (i in 0...inv) frequencies[i] = (mag = Math.sqrt(__freqReals[i] * __freqReals[i] + __freqImags[i] * __freqImags[i])) < 0.001 ? 0 : mag;
frequencies.resize(__N2);
if (fftN == 1) frequencies[0] = __freqSamples[0];
else {
for (i in 0...fftN) {
__freqReals[__reverseIndices[i]] = __freqSamples[i] * __windows[i];
__freqImags[i] = 0;
}
// https://github.com/FunkinCrew/grig.audio/commit/8567c4dad34cfeaf2ff23fe12c3796f5db80685e
inline function butterfly4PointOptimized(i0:Int, i1:Int, i2:Int, i3:Int, w1_idx:Int, w2_idx:Int, w3_idx:Int) {
// Load input values
var x0r = __freqReals[i0];
var x0i = __freqImags[i0];
// Apply twiddle factors to x1, x2, x3
// x1 = workingData[i1] * twiddle1
var x1r_raw = __freqReals[i1];
var x1i_raw = __freqImags[i1];
var tw1r = __twiddleReals[w1_idx];
var tw1i = __twiddleImags[w1_idx];
var x1r = x1r_raw * tw1r - x1i_raw * tw1i;
var x1i = x1r_raw * tw1i + x1i_raw * tw1r;
// x2 = workingData[i2] * twiddle2
var x2r_raw = __freqReals[i2];
var x2i_raw = __freqImags[i2];
var tw2r = __twiddleReals[w2_idx];
var tw2i = __twiddleImags[w2_idx];
var x2r = x2r_raw * tw2r - x2i_raw * tw2i;
var x2i = x2r_raw * tw2i + x2i_raw * tw2r;
// x3 = workingData[i3] * twiddle3
var x3r_raw = __freqReals[i3];
var x3i_raw = __freqImags[i3];
var tw3r = __twiddleReals[w3_idx];
var tw3i = __twiddleImags[w3_idx];
var x3r = x3r_raw * tw3r - x3i_raw * tw3i;
var x3i = x3r_raw * tw3i + x3i_raw * tw3r;
// Compute intermediate values for 4-point DFT
var t0r = x0r + x2r; // (x0 + x2).real
var t0i = x0i + x2i; // (x0 + x2).imag
var t1r = x0r - x2r; // (x0 - x2).real
var t1i = x0i - x2i; // (x0 - x2).imag
var t2r = x1r + x3r; // (x1 + x3).real
var t2i = x1i + x3i; // (x1 + x3).imag
var t3r = x1r - x3r; // (x1 - x3).real
var t3i = x1i - x3i; // (x1 - x3).imag
// Apply j multiplication: j * (a + jb) = -b + ja
var jt3r = -t3i; // j * t3.real = -t3.imag
var jt3i = t3r; // j * t3.imag = t3.real
// Final 4-point DFT butterfly outputs
__freqReals[i0] = t0r + t2r; // X[k]
__freqImags[i0] = t0i + t2i;
__freqReals[i1] = t1r - jt3r; // X[k + N/4]
__freqImags[i1] = t1i - jt3i;
__freqReals[i2] = t0r - t2r; // X[k + N/2]
__freqImags[i2] = t0i - t2i;
__freqReals[i3] = t1r + jt3r; // X[k + 3N/4]
__freqImags[i3] = t1i + jt3i;
}
inline function butterfly2PointOptimized(i0:Int, i1:Int, w_idx:Int) {
var tempr = __freqReals[i1] * __twiddleReals[w_idx] - __freqImags[i1] * __twiddleImags[w_idx];
var tempi = __freqReals[i1] * __twiddleImags[w_idx] + __freqImags[i1] * __twiddleReals[w_idx];
__freqReals[i1] = __freqReals[i0] - tempr;
__freqImags[i1] = __freqImags[i0] - tempi;
__freqReals[i0] += tempr;
__freqImags[i0] += tempi;
}
var size = 1, n, s, start, t;
for (radix in __factors) {
n = Math.floor(fftN / (size *= radix));
s = size >> (radix >> 1);
if (radix == 4) for (i in 0...n) {
start = i * size;
for (k in 0...s)
butterfly4PointOptimized(t = start + k, t = (t + s), t = (t + s), t = (t + s),
(k * n) % fftN, (2 * k * n) % fftN, (3 * k * n) % fftN);
}
else for (i in 0...n) {
start = i * size;
for (k in 0...s) butterfly2PointOptimized(t = start + k, t = (t + s), (k * n) % fftN);
}
}
var inv = 1.0 / fftN;
frequencies[0] = Math.sqrt(__freqReals[0] * __freqReals[0] + __freqImags[0] * __freqImags[0]) * inv;
for (i in 1...__N2) frequencies[i] = 2 * Math.sqrt(__freqReals[i] * __freqReals[i] + __freqImags[i] * __freqImags[i]) * inv;
}
return frequencies;
}
@@ -248,7 +348,7 @@ class AudioAnalyzer {
__sampleIndex = 0;
__check();
__read(startPos, startPos + (length / __toBits), mono ? __getSamplesCallbackMerge : __getSamplesCallback);
__read(startPos, startPos + (length / __toBits * buffer.channels), mono ? __getSamplesCallbackMerge : __getSamplesCallback);
__sampleOutput = null;
return output;
@@ -315,16 +415,25 @@ class AudioAnalyzer {
var n = Math.floor((endPos - startPos) * __toBits);
if (startPos >= time && startPos < backend.bufferTimes[backend.bufferSizes.length - 1] * 1000) {
var pos = Math.floor((startPos - time) * __toBits), buf = backend.bufferDatas[i].buffer, size = backend.bufferSizes[i], c = 0;
while (pos > size) {
if (++i >= backend.bufferSizes.length) {
n = 0;
break;
}
pos -= size;
buf = backend.bufferDatas[i].buffer;
size = backend.bufferSizes[i];
}
pos -= pos % __sampleSize;
while (n > 0) {
callback(getByte(buf, pos, __wordSize), c);
if (++c > buffer.channels) c = 0;
if ((pos += __wordSize) >= size) {
if (++i >= backend.bufferDatas.length) break;
if (++i >= backend.bufferSizes.length) break;
pos = 0;
buf = backend.bufferDatas[i].buffer;
size = backend.bufferSizes[i];
pos = 0;
}
n -= __wordSize;
}