我正在寻找一种基于浏览器的录音方式，直到发生沉默。
可以在Firefox和Chrome中使用麦克风录制HTML音频 - 使用Recordmp3js，请参阅：http://nusofthq.com/blog/recording-mp3-using-only-html5-and-javascript-recordmp3-js/和github上的代码：http://github.com/nusofthq/Recordmp3js
我无法看到一种方法来改变代码记录直到沉默。
记录，直到沉默可以使用Java为原生Android应用程序完成（和调整） - 请参阅：Android audio capture silence detection
qazxsw poi演示了一个浏览器可以做到的 - 但我怎样才能使用Javascript？有任何想法吗？
如果您使用Web Audio API，请通过调用：navigator.getUserMedia打开实时麦克风音频捕获，然后使用：createScriptProcessor创建节点，然后为该节点分配其事件的回调：onaudioprocess。在你的回调函数里面（我使用script_processor_analysis_node）你可以访问实时的实时音频缓冲区，然后你可以解析它寻找静音（振幅低的某个时间长度[保持接近于零]）。
对于正常的时域音频曲线，请参阅：array_time_domain，每次调用回调时都会重新填充script_processor_analysis_node ...类似于频域请参阅array_freq_domain
调低扬声器音量或使用耳机以避免来自麦克风的反馈 - >扬声器 - >麦克风......
Google Voice Search
这是一个老帖子，但我相信很多人会有同样的问题所以我在这里发布我的解决方案。使用<html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>capture microphone then show time & frequency domain output</title>
<script type="text/javascript">
var webaudio_tooling_obj = function () {
var audioContext = new AudioContext();
console.log("audio is starting up ...");
var BUFF_SIZE_RENDERER = 16384;
var audioInput = null,
microphone_stream = null,
gain_node = null,
script_processor_node = null,
script_processor_analysis_node = null,
analyser_node = null;
if (!navigator.getUserMedia)
navigator.getUserMedia = navigator.getUserMedia || navigator.webkitGetUserMedia ||
navigator.mozGetUserMedia || navigator.msGetUserMedia;
if (navigator.getUserMedia){
navigator.getUserMedia({audio:true},
function(stream) {
start_microphone(stream);
},
function(e) {
alert('Error capturing audio.');
}
);
} else { alert('getUserMedia not supported in this browser.'); }
// ---
function show_some_data(given_typed_array, num_row_to_display, label) {
var size_buffer = given_typed_array.length;
var index = 0;
console.log("__________ " + label);
if (label === "time") {
for (; index < num_row_to_display && index < size_buffer; index += 1) {
var curr_value_time = (given_typed_array[index] / 128) - 1.0;
console.log(curr_value_time);
}
} else if (label === "frequency") {
for (; index < num_row_to_display && index < size_buffer; index += 1) {
console.log(given_typed_array[index]);
}
} else {
throw new Error("ERROR - must pass time or frequency");
}
}
function process_microphone_buffer(event) {
var i, N, inp, microphone_output_buffer;
microphone_output_buffer = event.inputBuffer.getChannelData(0); // just mono - 1 channel for now
}
function start_microphone(stream){
gain_node = audioContext.createGain();
gain_node.connect( audioContext.destination );
microphone_stream = audioContext.createMediaStreamSource(stream);
microphone_stream.connect(gain_node);
script_processor_node = audioContext.createScriptProcessor(BUFF_SIZE_RENDERER, 1, 1);
script_processor_node.onaudioprocess = process_microphone_buffer;
microphone_stream.connect(script_processor_node);
// --- enable volume control for output speakers
document.getElementById('volume').addEventListener('change', function() {
var curr_volume = this.value;
gain_node.gain.value = curr_volume;
console.log("curr_volume ", curr_volume);
});
// --- setup FFT
script_processor_analysis_node = audioContext.createScriptProcessor(2048, 1, 1);
script_processor_analysis_node.connect(gain_node);
analyser_node = audioContext.createAnalyser();
analyser_node.smoothingTimeConstant = 0;
analyser_node.fftSize = 2048;
microphone_stream.connect(analyser_node);
analyser_node.connect(script_processor_analysis_node);
var buffer_length = analyser_node.frequencyBinCount;
var array_freq_domain = new Uint8Array(buffer_length);
var array_time_domain = new Uint8Array(buffer_length);
console.log("buffer_length " + buffer_length);
script_processor_analysis_node.onaudioprocess = function() {
// get the average for the first channel
analyser_node.getByteFrequencyData(array_freq_domain);
analyser_node.getByteTimeDomainData(array_time_domain);
// draw the spectrogram
if (microphone_stream.playbackState == microphone_stream.PLAYING_STATE) {
show_some_data(array_freq_domain, 5, "frequency");
show_some_data(array_time_domain, 5, "time"); // store this to record to aggregate buffer/file
// examine array_time_domain for near zero values over some time period
}
};
}
}(); // webaudio_tooling_obj = function()
</script>
</head>
<body>
<p>Volume</p>
<input id="volume" type="range" min="0" max="1" step="0.1" value="0.5"/>
</body>
</html>
下面是我用于电子应用程序的示例演示代码
hark.js
来自@Scott Stensland的解决方案不允许我解析沉默。当我解析两个数组时，我得到相同的值 - 这就是我在解析 hark = require('./node_modules/hark/hark.bundle.js')
navigator.getUserMedia({ audio : true}, onMediaSuccess, function(){});
function onMediaSuccess(blog) {
var options = {};
var speechEvents = hark(blog, options);
speechEvents.on('speaking', function() {
console.log('speaking');
});
speechEvents.on('stopped_speaking', function() {
console.log('stopped_speaking');
});
};
时总是在解析0和arrayFreqDomain时总是得到128
arrayTimeDomain