dev@129: /**
dev@129:  * Created by lucast on 16/03/2017.
dev@129:  */
dev@236: import {RealFft, KissRealFft} from 'piper/fft/RealFft';
dev@236: import {hann} from 'piper/FftUtilities';
dev@236: import {Framing} from 'piper';
dev@289: import Waves from 'waves-ui-piper';
dev@129: 
dev@129: class SpectrogramEntity extends Waves.utils.MatrixEntity {
dev@129: 
dev@129:   private samples: Float32Array;
cannam@168:   private sampleRate: number;
dev@129:   private framing: Framing;
dev@129:   private fft: RealFft;
dev@129:   private real: Float32Array;
dev@129:   private nCols: number;
cannam@130:   private columnHeight: number;
dev@129:   private window: Float32Array;
dev@129: 
cannam@168:   constructor(samples: Float32Array, options: Framing & Object, sampleRate: number) {
dev@129:     super();
dev@129:     this.samples = samples;
cannam@168:     this.sampleRate = sampleRate;
dev@129:     this.framing = options;
dev@129:     this.real = new Float32Array(this.framing.blockSize);
dev@236:     this.nCols = Math.floor(this.samples.length / this.framing.stepSize); // !!! not correct
cannam@130:     this.columnHeight = Math.round(this.framing.blockSize / 2) + 1;
dev@129:     this.fft = new KissRealFft(this.framing.blockSize);
dev@129:     this.window = hann(this.framing.blockSize);
dev@129:   }
dev@129: 
cannam@131:   dispose(): void {
cannam@131:     this.fft.dispose();
cannam@131:   }
cannam@131: 
dev@129:   getColumnCount(): number {
dev@129:     return this.nCols;
dev@129:   }
dev@129: 
dev@129:   getColumnHeight(): number {
cannam@130:     return this.columnHeight;
dev@129:   }
dev@129: 
cannam@168:   getStepDuration(): number {
cannam@168:     return this.framing.stepSize / this.sampleRate;
cannam@168:   }
dev@236: 
dev@129:   getColumn(n: number): Float32Array {
dev@129: 
dev@129:     const startSample = n * this.framing.stepSize;
dev@129:     const sz = this.framing.blockSize;
dev@129: 
dev@129:     this.real.fill(0);
dev@129: 
dev@129:     let available = sz;
dev@129:     if (startSample + sz >= this.samples.length) {
dev@129:       available = this.samples.length - startSample;
dev@129:     }
dev@129: 
dev@129:     for (let i = 0; i < available; ++i) {
dev@129:       this.real[i] = this.samples[startSample + i] * this.window[i];
dev@129:     }
dev@129: 
dev@129:     const complex = this.fft.forward(this.real);
dev@129: 
dev@129:     const h = this.getColumnHeight();
dev@129:     const col = new Float32Array(h);
dev@129: 
cannam@130:     const scale = 1.0 / Math.sqrt(sz);
dev@129:     for (let i = 0; i < h; ++i) {
dev@236:       const re: number = complex[i * 2] * scale;
dev@236:       const im: number = complex[i * 2 + 1] * scale;
dev@236:       col[i] = Math.sqrt(re * re + im * im);
dev@129:     }
dev@129: 
dev@129:     return col;
dev@129:   }
dev@129: }
dev@129: 
dev@129: export class WavesSpectrogramLayer extends Waves.core.Layer {
dev@236:   constructor(bufferIn: AudioBuffer,
dev@129:               options: Framing & Object) {
dev@129: 
dev@129:     const defaults = {
dev@129:       normalise: 'hybrid',
dev@129:       gain: 40.0,
cannam@162:       channel: -1,
dev@129:       stepSize: 512,
dev@129:       blockSize: 1024
dev@129:     };
dev@129: 
dev@129:     const mergedOptions: Framing & Object & {channel: number} =
dev@129:       Object.assign({}, defaults, options);
dev@129: 
cannam@162:     const getSamples = ((buffer, channel) => {
cannam@162:       const nch = buffer.numberOfChannels;
dev@236:       if (channel >= 0 || nch === 1) {
dev@236:         if (channel < 0) {
dev@236:           channel = 0;
dev@236:         }
dev@236:         return buffer.getChannelData(channel);
cannam@162:       } else {
cannam@163:         const before = performance.now();
dev@236:         console.log('mixing down ' + nch + ' channels for spectrogram...');
dev@236:         const mixed = Float32Array.from(buffer.getChannelData(0));
dev@236:         const n = mixed.length;
dev@236:         for (let ch = 1; ch < nch; ++ch) {
dev@236:           const buf = buffer.getChannelData(ch);
dev@236:           for (let i = 0; i < n; ++i) {
dev@236:             mixed[i] += buf[i];
dev@236:           }
dev@236:         }
dev@236:         const scale = 1.0 / nch;
dev@236:         for (let i = 0; i < n; ++i) {
dev@236:           mixed[i] *= scale;
dev@236:         }
dev@236:         console.log('done in ' + (performance.now() - before) + 'ms');
dev@236:         return mixed;
cannam@162:       }
cannam@162:     });
dev@236: 
dev@236:     super(
dev@236:       'entity',
dev@236:       new SpectrogramEntity(getSamples(bufferIn, mergedOptions.channel),
dev@236:         mergedOptions,
dev@236:         bufferIn.sampleRate),
dev@236:       mergedOptions
dev@236:     );
dev@129: 
dev@129:     this.configureShape(Waves.shapes.Matrix, {}, mergedOptions);
dev@129:   }
dev@129: }