Kyauta Mai Nazarin Yanayin Sauti

Yadda Yake Aiki

Mai Nazarin Spectrum na Sauti yana gudana gaba ɗaya a burauzarka ta amfani da AnalyserNode na Web Audio API, wanda yake lissafta FFT (Fast Fourier Transform) na lokaci na gaskiya a kan bayanan sauti daga fayil ko makirifo. Ana zana kowace firam da lambar Canvas 2D da aka rubuta da hannu — babu ɗakin karatu na gani da abin ya shafa, kuma babu sauti da yake barin na'urarka.

1. 1
   Ana warware sautin kuma a ba shi hanya

   Lokacin da ka loda fayil, Web Audio API yana warware shi zuwa AudioBuffer kuma yana ba shi hanya ta hanyar MediaElementAudioSourceNode zuwa AnalyserNode. Don shigarwar makirifo, getUserMedia() yana kama gudan kuma yana ciyar da shi ta hanyar MediaStreamAudioSourceNode maimakon haka — tare da soke amo, murkushe hayaniya, da riba ta atomatik duk an kashe su don ka ga siginar danye.
2. 2
   AnalyserNode yana gudanar da FFT a kowace firam

   A kowace firam ta motsi (ta hanyar requestAnimationFrame), lambar tana kiran getFloatFrequencyData() don karanta spectrum na ƙarfin FFT na yanzu a dBFS, da getFloatTimeDomainData() don samfuran waveform danye. Girman FFT ana iya saita shi daga 2048 zuwa 16384 bins, yana bayar da ƙudurin mitar kamar kusan 2.7 Hz/bin a 44.1 kHz.
3. 3
   Canvas 2D yana zana zaɓaɓɓen dubawa

   Dubawar Analyzer tana mayar da bins na FFT zuwa gefen X na log-mitar (20 Hz–20 kHz) da gefen Y na dBFS, tana zana spectrum a matsayin layi cike, tana kuma sanya alamar tafiya ta matuƙa mai raguwa. Ana gano mitar da ta fi rinjaya ta amfani da tsaka-tsaki na parabolic kewaye bin na matuƙa, sannan a mayar da shi zuwa mafi kusar nota ta kiɗa ta iri ɗaya-tempered (A4=440 Hz) tare da nuna karkacewa ta cent a karatun. Dubawar Spectrogram tana sakewa canvas ɗin pixel guda hagu a kowace firam kuma tana zana sabon shafi ta amfani da tsarin launi irin na inferno. Dubawar Artistic tana amfani da bayanan mitar ko lokaci na ƙudurin byte don yanayoyin ado na sanda, waveform, ko da'ira.
4. 4
   Fitarwa ta Canvas da MediaRecorder

   Ajiye PNG yana kiran canvas.toBlob() don ɓoye firam ɗin yanzu. Rikodin bidiyo yana amfani da canvas.captureStream(30) haɗe da wani tap na sauti daga MediaStreamAudioDestinationNode, wanda ake tura shi zuwa MediaRecorder mai samar da WebM ko MP4. Fitarwar WAV tana ɓoye da hannu fayil na RIFF na PCM 16-bit daga AudioBuffer ta amfani da DataView — babu mai ɓoyewa na waje.

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