我正在使用可视化工具构建HTML5语音录制,但是运行时程序在onaudioprocess中给出了一个错误,即未声明变量这是因为onaudioprocess没有运行。出了什么问题?这是我的完整代码:
// variables
var leftchannel = [];
var rightchannel = [];
var recorder = null;
var recording = false;
var recordingLength = 0;
var volume = null;
var audioInput = null;
var sampleRate = 44100;
var audioContext = null;
var context = null;
var outputString;
if (!navigator.getUserMedia)
navigator.getUserMedia = navigator.getUserMedia ||
navigator.webkitGetUserMedia ||
navigator.mozGetUserMedia ||
navigator.msGetUserMedia;
if (navigator.getUserMedia){
navigator.getUserMedia({audio:true}, success, function(e) {
alert('Error capturing audio.');
});
} else alert('getUserMedia not supported in this browser.');
function getVal(value)
{
if ( value == "record"){
recording = true;
// reset the buffers for the new recording
leftchannel.length = rightchannel.length = 0;
recordingLength = 0;
document.getElementById('output').innerHTML="Recording now...";
} else if ( value == "stop" ){
// we stop recording
recording = false;
document.getElementById('output').innerHTML="Building wav file...";
// we flat the left and right channels down
var leftBuffer = mergeBuffers ( leftchannel, recordingLength );
var rightBuffer = mergeBuffers ( rightchannel, recordingLength );
// we interleave both channels together
var interleaved = interleave ( leftBuffer, rightBuffer );
var buffer = new ArrayBuffer(44 + interleaved.length * 2);
var view = new DataView(buffer);
// RIFF chunk descriptor
writeUTFBytes(view, 0, 'RIFF');
view.setUint32(4, 44 + interleaved.length * 2, true);
writeUTFBytes(view, 8, 'WAVE');
// FMT sub-chunk
writeUTFBytes(view, 12, 'fmt ');
view.setUint32(16, 16, true);
view.setUint16(20, 1, true);
// stereo (2 channels)
view.setUint16(22, 2, true);
view.setUint32(24, sampleRate, true);
view.setUint32(28, sampleRate * 4, true);
view.setUint16(32, 4, true);
view.setUint16(34, 16, true);
// data sub-chunk
writeUTFBytes(view, 36, 'data');
view.setUint32(40, interleaved.length * 2, true);
var lng = interleaved.length;
var index = 44;
var volume = 1;
for (var i = 0; i < lng; i++){
view.setInt16(index, interleaved[i] * (0x7FFF * volume), true);
index += 2;
}
var blob = new Blob ( [ view ], { type : 'audio/wav' } );
// let's save it locally
document.getElementById('output').innerHTML='Handing off the file now...';
var url = (window.URL || window.webkitURL).createObjectURL(blob);
var li = document.createElement('li');
var au = document.createElement('audio');
var hf = document.createElement('a');
au.controls = true;
au.src = url;
hf.href = url;
hf.download = 'audio_recording_' + new Date().getTime() + '.wav';
hf.innerHTML = hf.download;
li.appendChild(au);
li.appendChild(hf);
recordingList.appendChild(li);
}
}
function success(e){
audioContext = window.AudioContext || window.webkitAudioContext;
context = new audioContext();
volume = context.createGain();
// creates an audio node from the microphone incoming stream(source)
source = context.createMediaStreamSource(e);
// connect the stream(source) to the gain node
source.connect(volume);
var bufferSize = 2048;
recorder = context.createScriptProcessor(bufferSize, 2, 2);
//node for the visualizer
analyser = context.createAnalyser();
analyser.smoothingTimeConstant = 0.3;
analyser.fftSize = 1024;
analyser2 = context.createAnalyser();
analyser2.smoothingTimeConstant = 0.0;
analyser2.fftSize = 1024;
splitter = context.createChannelSplitter();
//when recording happens
recorder.onaudioprocess = function(e){
if (!recording) return;
var left = e.inputBuffer.getChannelData (0);
var right = e.inputBuffer.getChannelData (1);
// get the average of the first channel, bincount is fftsize / 2
var array = new Uint8Array(analyser.frequencyBinCount);
analyser.getByteFrequencyData(array);
var average = getAverageVolume(array);
// get the average for the second channel
var array2 = new Uint8Array(analyser2.frequencyBinCount);
analyser2.getByteFrequencyData(array2);
var average2 = getAverageVolume(array2);
// clear the current state
context.clearRect(0, 0, 60, 130);
// set the fill style
context.fillStyle=gradient;
// create the meters
context.fillRect(0,130-average,25,130);
context.fillRect(30,130-average2,25,130);
}
function getAverageVolume(array) {
var values = 0;
var average;
var length = array.length;
// get all the frequency amplitudes
for (var i = 0; i < length; i++) {
values += array[i];
}
average = values / length;
return average;
}
leftchannel.push (new Float32Array (left));
rightchannel.push (new Float32Array (right));
recordingLength += bufferSize;
// we connect the recorder(node to destination(speakers))
volume.connect(splitter);
splitter.connect(analyser, 0, 0);
splitter.connect(analyser2, 1, 0);
analyser.connect(recorder);
recorder.connect(context.destination);
}
function mergeBuffers(channelBuffer, recordingLength){
var result = new Float32Array(recordingLength);
var offset = 0;
var lng = channelBuffer.length;
for (var i = 0; i < lng; i++){
var buffer = channelBuffer[i];
result.set(buffer, offset);
offset += buffer.length;
}
return result;
}
function interleave(leftChannel, rightChannel){
var length = leftChannel.length + rightChannel.length;
var result = new Float32Array(length);
var inputIndex = 0;
for (var index = 0; index < length; ){
result[index++] = leftChannel[inputIndex];
result[index++] = rightChannel[inputIndex];
inputIndex++;
}
return result;
}
function writeUTFBytes(view, offset, string){
var lng = string.length;
for (var i = 0; i < lng; i++){
view.setUint8(offset + i, string.charCodeAt(i));
}
}
请帮助
答案 0 :(得分:0)
问题解决了,推动左右声道应该在onaudioprocess
之内 leftchannel.push (new Float32Array (left));
rightchannel.push (new Float32Array (right));
recordingLength += bufferSize;