diff --git a/source/funkin/backend/utils/AudioAnalyzer.hx b/source/funkin/backend/utils/AudioAnalyzer.hx index 67206dd6..2eeedb6b 100644 --- a/source/funkin/backend/utils/AudioAnalyzer.hx +++ b/source/funkin/backend/utils/AudioAnalyzer.hx @@ -77,7 +77,7 @@ class AudioAnalyzer { * Creates an analyzer for specified FlxSound * @param sound An FlxSound to analyze. **/ - public function new(sound:FlxSound, fftN = 2048) { + public function new(sound:FlxSound, fftN = 512) { this.sound = sound; this.fftN = fftN; __check(); @@ -108,26 +108,23 @@ class AudioAnalyzer { 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); + __windows[i] = 0.42 - 0.5 * Math.cos(2 * Math.PI * f) + 0.08 * Math.cos(4 * Math.PI * f); __reverseIndices[i] = __bitReverse(i); - __twiddleReals[i] = Math.cos(a = 2 * Math.PI * i / fftN); + __twiddleReals[i] = Math.cos(a = -2 * Math.PI * i / fftN); __twiddleImags[i] = Math.sin(a); } __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; + while (inv % 4 == 0) { + __factors.push(4); + inv >>= 2; + } + + while (inv % 2 == 0) { + __factors.push(2); + inv >>= 1; } return fftN; @@ -149,40 +146,37 @@ class AudioAnalyzer { return y; } - public function getLevels(startPos:Float, barCount:Int, ?levels:Array, delta = 0.0, dbRange = 50.0, minFreq = 20.0, maxFreq = 20000.0):Array { + public function getLevels(startPos:Float, barCount:Int, ?levels:Array, delta = 0.0, minDb = -70, maxDb = -10, minFreq = 20.0, maxFreq = 22000.0):Array { __frequencies = getFrequencies(startPos, __frequencies); if (levels == null) levels = []; levels.resize(barCount); var logMin = Math.log(minFreq), logMax = Math.log(maxFreq); + var logRange = logMax - logMin, dbRange = maxDb - minDb; inline function calculateScale(i:Int) - return CoolUtil.bound(Math.exp(logMin + ((logMax - logMin) * i / barCount)) * fftN / buffer.sampleRate, 0, __N2 - 1); + return CoolUtil.bound(Math.exp(logMin + (logRange * i / (barCount + 1))) * fftN / buffer.sampleRate, 0, __N2 - 1); 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 ((range = (s2 = calculateScale(i + 1)) - s1) < 1) { + i2 = Math.ceil(s2); if (i2 == i1) v = __frequencies[i1] * range; - else v = (s1 + (s2 - s1) * (s1 - i1)) * range; + else v = (__frequencies[i1] + (__frequencies[i2] - __frequencies[i1]) * (s1 - i1)) * range; } else { v = __frequencies[i1] * (Math.ceil(s1) - i1); - while (++i1 < i2) v += __frequencies[i1]; - v += __frequencies[i2] * (s2 - Math.floor(s2)); + if (i1 != (i2 = Math.floor(s2))) { + while (++i1 < i2) v += __frequencies[i1]; + v += __frequencies[i2] * (s2 - Math.floor(s2)); + } } - 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); - - if (delta > 0 && levels[i] > v) levels[i] -= (levels[i] - v) * delta; + v = ((20 * Math.log(v) / 2.302585092994046) - minDb) / dbRange; + if (delta > 0 && delta < 1 && v < levels[i]) levels[i] -= Math.pow(levels[i] - v, 2) * delta; else levels[i] = v; } @@ -194,6 +188,71 @@ class AudioAnalyzer { * @return Output of frequencies ranging from 1 to fftN/2. **/ public function getFrequencies(startPos:Float, ?frequencies:Array):Array { + // 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; + } + __freqSamples = getSamples(startPos, fftN, true, __freqSamples); if (frequencies == null) frequencies = []; @@ -201,89 +260,26 @@ class AudioAnalyzer { if (fftN == 1) frequencies[0] = __freqSamples[0]; else { + var n; for (i in 0...fftN) { - __freqReals[__reverseIndices[i]] = __freqSamples[i] * __windows[i]; - __freqImags[i] = 0; + n = __reverseIndices[i]; + __freqReals[n] = __freqSamples[i] * __windows[i]; + __freqImags[n] = 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; + var size = 1, s2, start, t; for (radix in __factors) { n = Math.floor(fftN / (size *= radix)); - s = size >> (radix >> 1); + s2 = 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), + for (k in 0...s2) + butterfly4PointOptimized(t = start + k, t = (t + s2), t = (t + s2), t = (t + s2), (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); + for (k in 0...s2) butterfly2PointOptimized(t = start + k, t = (t + s2), (k * n) % fftN); } } @@ -344,7 +340,7 @@ class AudioAnalyzer { * @return Output of **/ public function getSamples(startPos:Float, length:Int, mono = true, ?output:Array):Array { - ((output == null) ? (__sampleOutput = output = []) : (__sampleOutput = output)).resize((__sampleOutputLength = length) * (mono ? 1 : buffer.channels)); + ((output == null) ? (__sampleOutput = output = []) : (__sampleOutput = output)).resize(__sampleOutputLength = length * (mono ? 1 : buffer.channels)); __sampleIndex = 0; __check(); @@ -354,7 +350,6 @@ class AudioAnalyzer { return output; } - // TODO: check later if this formula is correct. function __getSamplesCallbackMerge(b:Int, c:Int):Void if (__sampleIndex < __sampleOutputLength) { if (c == 0) __sampleOutput[__sampleIndex] = b / buffer.channels / byteSize; else if (c == buffer.channels) {