45 lines
1.4 KiB
Haxe
45 lines
1.4 KiB
Haxe
package funkin.backend.utils;
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import flixel.sound.FlxSound;
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import lime.media.AudioBuffer;
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// Thank you yosh :DDD -lunar
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// (https://github.com/CodenameCrew/YoshiCrafterEngine/blob/main/source/WaveformSprite.hx)
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class AudioAnalyzer {
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public var buffer:AudioBuffer;
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var __peakByte:Float = 0;
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var __timeMulti:Float = 0;
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public function new(sound:FlxSound) {
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@:privateAccess buffer = sound._sound.__buffer;
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__peakByte = Math.pow(2, buffer.bitsPerSample-1)-1;
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__timeMulti = 1 / (1 / buffer.sampleRate);
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__timeMulti *= buffer.bitsPerSample;
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__timeMulti -= __timeMulti % buffer.bitsPerSample;
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}
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public function analyze(startPos:Float, endPos:Float):Float {
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var bitsPerSample = buffer.bitsPerSample;
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var multi = __timeMulti / 4000 / bitsPerSample;
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var bytesStartPos:Int = Math.floor(startPos * multi) * bitsPerSample;
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var bytesEndPos:Int = Math.floor(endPos * multi) * bitsPerSample;
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bytesStartPos -= bytesStartPos % bitsPerSample;
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bytesEndPos -= bytesEndPos % bitsPerSample;
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var dataBuffer = buffer.data.buffer;
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var maxByte:Int = 0;
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for(i in 0...Math.floor((bytesEndPos - bytesStartPos) / bitsPerSample)) {
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var bytePos = bytesStartPos + (i * bitsPerSample);
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// What if bitsPerSample is 8? or 32? or 64? -Ne_Eo
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var byte:Int = dataBuffer.get(bytePos) | (dataBuffer.get(bytePos + 1) << 8);
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if (byte > 256 * 128) byte -= 256 * 256;
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if (maxByte < byte) maxByte = byte;
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}
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return maxByte/__peakByte;
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}
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} |