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// Load one mp3 file for one note.
// url = the base url for the soundfont
// instrument = the instrument name (e.g. "acoustic_grand_piano")
// name = the pitch name (e.g. "A3")
var soundsCache = require("./sounds-cache");
var getNote = function (url, instrument, name, audioContext) {
if (!soundsCache[instrument]) soundsCache[instrument] = {};
var instrumentCache = soundsCache[instrument];
if (!instrumentCache[name])
instrumentCache[name] = new Promise(function (resolve, reject) {
var xhr = new XMLHttpRequest();
let noteUrl = url + instrument + "-mp3/" + name + ".mp3";
xhr.open("GET", noteUrl, true);
xhr.responseType = "arraybuffer";
xhr.onload = function () {
if (xhr.status !== 200) {
reject(Error("Can't load sound at " + noteUrl + ' status=' + xhr.status));
return
}
var noteDecoded = function(audioBuffer) {
resolve({instrument: instrument, name: name, status: "loaded", audioBuffer: audioBuffer})
}
var maybePromise = audioContext.decodeAudioData(xhr.response, noteDecoded, function () {
reject(Error("Can't decode sound at " + noteUrl));
});
// In older browsers `BaseAudioContext.decodeAudio()` did not return a promise
if (maybePromise && typeof maybePromise.catch === "function") maybePromise.catch(reject);
};
xhr.onerror = function () {
reject(Error("Can't load sound at " + noteUrl));
};
xhr.send();
})
.catch(err => {
console.error("Didn't load note", instrument, name, ":", err.message);
throw err;
});
return instrumentCache[name];
};
module.exports = getNote;
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