92 lines
2.2 KiB
JavaScript
92 lines
2.2 KiB
JavaScript
importScripts("Mp3LameEncoder.min.js");
|
|
|
|
var NUM_CH = 2, // constant
|
|
sampleRate = 44100,
|
|
options = undefined,
|
|
maxBuffers = undefined,
|
|
encoder = undefined,
|
|
recBuffers = undefined,
|
|
bufferCount = 0;
|
|
|
|
function error(message) {
|
|
self.postMessage({ command: "error", message: "mp3: " + message });
|
|
}
|
|
|
|
function init(data) {
|
|
if (data.config.numChannels === NUM_CH) {
|
|
sampleRate = data.config.sampleRate;
|
|
options = data.options;
|
|
} else
|
|
error("numChannels must be " + NUM_CH);
|
|
};
|
|
|
|
function setOptions(opt) {
|
|
if (encoder || recBuffers)
|
|
error("cannot set options during recording");
|
|
else
|
|
options = opt;
|
|
}
|
|
|
|
function start(bufferSize) {
|
|
maxBuffers = Math.ceil(options.timeLimit * sampleRate / bufferSize);
|
|
if (options.encodeAfterRecord)
|
|
recBuffers = [];
|
|
else
|
|
encoder = new Mp3LameEncoder(sampleRate, options.mp3.bitRate);
|
|
}
|
|
|
|
function record(buffer) {
|
|
if (bufferCount++ < maxBuffers)
|
|
if (encoder)
|
|
encoder.encode(buffer);
|
|
else
|
|
recBuffers.push(buffer);
|
|
else
|
|
self.postMessage({ command: "timeout" });
|
|
};
|
|
|
|
function postProgress(progress) {
|
|
self.postMessage({ command: "progress", progress: progress });
|
|
};
|
|
|
|
function finish() {
|
|
if (recBuffers) {
|
|
postProgress(0);
|
|
encoder = new Mp3LameEncoder(sampleRate, options.mp3.bitRate);
|
|
var timeout = Date.now() + options.progressInterval;
|
|
while (recBuffers.length > 0) {
|
|
encoder.encode(recBuffers.shift());
|
|
var now = Date.now();
|
|
if (now > timeout) {
|
|
postProgress((bufferCount - recBuffers.length) / bufferCount);
|
|
timeout = now + options.progressInterval;
|
|
}
|
|
}
|
|
postProgress(1);
|
|
}
|
|
self.postMessage({
|
|
command: "complete",
|
|
blob: encoder.finish(options.mp3.mimeType)
|
|
});
|
|
cleanup();
|
|
};
|
|
|
|
function cleanup() {
|
|
encoder = recBuffers = undefined;
|
|
bufferCount = 0;
|
|
}
|
|
|
|
self.onmessage = function(event) {
|
|
var data = event.data;
|
|
switch (data.command) {
|
|
case "init": init(data); break;
|
|
case "options": setOptions(data.options); break;
|
|
case "start": start(data.bufferSize); break;
|
|
case "record": record(data.buffer); break;
|
|
case "finish": finish(); break;
|
|
case "cancel": cleanup();
|
|
}
|
|
};
|
|
|
|
self.postMessage({ command: "loaded" });
|