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added support for custom bit depth resampling #5

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4 changes: 3 additions & 1 deletion README.md
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Original file line number Diff line number Diff line change
Expand Up @@ -22,6 +22,8 @@ resampler(input, targetSampleRate, oncomplete);

`targetSampleRate` : The target sample rate after the re-sampling process. This number is limted based on the browser implementation (usually >=3000, <=192000)

`targetBitDepth` : The target bit depth after the re-sampling process. This number is limted based on the browser implementation (usually >=16, <=32)

`oncomplete`: Callback when the resampling process is completed. The argument to this callback is an Object which supports the following methods:

`getAudioBuffer` : Returns the resampler AudioBuffer
Expand All @@ -33,7 +35,7 @@ resampler(input, targetSampleRate, oncomplete);
```
resampler = require('audio-resampler');
var URL = "https://dl.dropboxusercontent.com/u/957/audio/sine.wav"
resampler(URL, 192000, function(event){
resampler(URL, 192000, 24, function(event){
event.getFile(function(fileEvent){
var a = document.createElement("a");
document.body.appendChild(a);
Expand Down
173 changes: 89 additions & 84 deletions bundle.js
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Original file line number Diff line number Diff line change
Expand Up @@ -56,7 +56,7 @@ window.addEventListener('load', function(){
spinner.style.display = "inherit";
input.disabled = true;
disableDragDrop(dropzone);
resampler(file, targetSampleRate, function(event){
resampler(file, targetSampleRate, 24, function(event){
event.getFile(function(fileEvent){
console.log(fileEvent);
spinner.style.display = "none";
Expand Down Expand Up @@ -95,95 +95,100 @@ var wal = new WebAudioLoader({
cache: false
});

function resampler(input, targetSampleRate, oncomplete) {
function resampler(input, targetSampleRate, targetBitDepth, oncomplete) {

if (!input && !targetSampleRate) {
return returnError('Error: First argument should be either a File, URL or AudioBuffer');
}
if (!input && !targetSampleRate && !targetBitDepth) {
return returnError('Error: First argument should be either a File, URL or AudioBuffer');
}

var inputType = Object.prototype.toString.call(input);
if (inputType !== '[object String]' &&
inputType !== '[object File]' &&
inputType !== '[object AudioBuffer]' &&
inputType !== '[object Object]') {
return returnError('Error: First argument should be either a File, URL or AudioBuffer');
}
var inputType = Object.prototype.toString.call(input);
if (inputType !== '[object String]' &&
inputType !== '[object File]' &&
inputType !== '[object AudioBuffer]' &&
inputType !== '[object Object]') {
return returnError('Error: First argument should be either a File, URL or AudioBuffer');
}

if (typeof targetSampleRate !== 'number' ||
targetSampleRate > 192000 || targetSampleRate < 3000) {
return returnError('Error: Second argument should be a numeric sample rate between 3000 and 192000');
}
if (typeof targetSampleRate !== 'number' ||
targetSampleRate > 192000 || targetSampleRate < 3000) {
return returnError('Error: Second argument should be a numeric sample rate between 3000 and 192000');
}

if (inputType === '[object String]' || inputType === '[object File]') {
console.log('Loading/decoding input', input);
wal.load(input, {
onload: function(err, audioBuffer) {
if (err) {
return returnError(err);
}
resampleAudioBuffer(audioBuffer);
}
});
} else if (inputType === '[object AudioBuffer]') {
resampleAudioBuffer(input);
} else if (inputType === '[object Object]' && input.leftBuffer && input.sampleRate) {
var numCh_ = input.rightBuffer ? 2 : 1;
var audioBuffer_ = audioContext.createBuffer(numCh_, input.leftBuffer.length, input.sampleRate);
resampleAudioBuffer(audioBuffer_);
} else {
return returnError('Error: Unknown input type');
}
if (typeof targetBitDepth !== 'number' ||
targetBitDepth > 32 || targetBitDepth < 16) {
return returnError('Error: Third argument should be a numeric bit depth between 16 and 32');
}

function returnError(errMsg) {
console.error(errMsg);
if (typeof oncomplete === 'function') {
oncomplete(new Error(errMsg));
}
return;
}
if (inputType === '[object String]' || inputType === '[object File]') {
console.log('Loading/decoding input', input);
wal.load(input, {
onload: function(err, audioBuffer) {
if (err) {
return returnError(err);
}
resampleAudioBuffer(audioBuffer);
}
});
} else if (inputType === '[object AudioBuffer]') {
resampleAudioBuffer(input);
} else if (inputType === '[object Object]' && input.leftBuffer && input.sampleRate) {
var numCh_ = input.rightBuffer ? 2 : 1;
var audioBuffer_ = audioContext.createBuffer(numCh_, input.leftBuffer.length, input.sampleRate);
resampleAudioBuffer(audioBuffer_);
} else {
return returnError('Error: Unknown input type');
}

function resampleAudioBuffer(audioBuffer) {


var numCh_ = audioBuffer.numberOfChannels;
var numFrames_ = audioBuffer.length * targetSampleRate / audioBuffer.sampleRate;

var offlineContext_ = new OfflineAudioContext(numCh_, numFrames_, targetSampleRate);
var bufferSource_ = offlineContext_.createBufferSource();
bufferSource_.buffer = audioBuffer;

offlineContext_.oncomplete = function(event) {
var resampeledBuffer = event.renderedBuffer;
console.log('Done Rendering');
if (typeof oncomplete === 'function') {
oncomplete({
getAudioBuffer: function() {
return resampeledBuffer;
},
getFile: function(fileCallback) {
var audioData = {
sampleRate: resampeledBuffer.sampleRate,
channelData: []
};
for (var i = 0; i < resampeledBuffer.numberOfChannels; i++) {
audioData.channelData[i] = resampeledBuffer.getChannelData(i);
}
WavEncoder.encode(audioData).then(function(buffer) {
var blob = new Blob([buffer], {
type: "audio/wav"
});
fileCallback(URL.createObjectURL(blob));
});
}
});
}
};

console.log('Starting Offline Rendering');
bufferSource_.connect(offlineContext_.destination);
bufferSource_.start(0);
offlineContext_.startRendering();
}
function returnError(errMsg) {
console.error(errMsg);
if (typeof oncomplete === 'function') {
oncomplete(new Error(errMsg));
}
return;
}

function resampleAudioBuffer(audioBuffer) {


var numCh_ = audioBuffer.numberOfChannels;
var numFrames_ = audioBuffer.length * targetSampleRate / audioBuffer.sampleRate;

var offlineContext_ = new OfflineAudioContext(numCh_, numFrames_, targetSampleRate);
var bufferSource_ = offlineContext_.createBufferSource();
bufferSource_.buffer = audioBuffer;

offlineContext_.oncomplete = function(event) {
var resampeledBuffer = event.renderedBuffer;
console.log('Done Rendering');
if (typeof oncomplete === 'function') {
oncomplete({
getAudioBuffer: function() {
return resampeledBuffer;
},
getFile: function(fileCallback) {
var audioData = {
sampleRate: resampeledBuffer.sampleRate,
channelData: []
};
for (var i = 0; i < resampeledBuffer.numberOfChannels; i++) {
audioData.channelData[i] = resampeledBuffer.getChannelData(i);
}
WavEncoder.encode(audioData, { float: false, bitDepth: targetBitDepth }).then(function(buffer) {
var blob = new Blob([buffer], {
type: "audio/wav"
});
fileCallback(URL.createObjectURL(blob));
});
}
});
}
};

console.log('Starting Offline Rendering');
bufferSource_.connect(offlineContext_.destination);
bufferSource_.start(0);
offlineContext_.startRendering();
}
}


Expand Down
2 changes: 1 addition & 1 deletion index.js
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Original file line number Diff line number Diff line change
Expand Up @@ -55,7 +55,7 @@ window.addEventListener('load', function(){
spinner.style.display = "inherit";
input.disabled = true;
disableDragDrop(dropzone);
resampler(file, targetSampleRate, function(event){
resampler(file, targetSampleRate, 24, function(event){
event.getFile(function(fileEvent){
console.log(fileEvent);
spinner.style.display = "none";
Expand Down
11 changes: 8 additions & 3 deletions lib/resampler.js
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Original file line number Diff line number Diff line change
Expand Up @@ -14,9 +14,9 @@ var wal = new WebAudioLoader({
cache: false
});

function resampler(input, targetSampleRate, oncomplete) {
function resampler(input, targetSampleRate, targetBitDepth, oncomplete) {

if (!input && !targetSampleRate) {
if (!input && !targetSampleRate && !targetBitDepth) {
return returnError('Error: First argument should be either a File, URL or AudioBuffer');
}

Expand All @@ -33,6 +33,11 @@ function resampler(input, targetSampleRate, oncomplete) {
return returnError('Error: Second argument should be a numeric sample rate between 3000 and 192000');
}

if (typeof targetBitDepth !== 'number' ||
targetBitDepth > 32 || targetBitDepth < 16) {
return returnError('Error: Third argument should be a numeric bit depth between 16 and 32');
}

if (inputType === '[object String]' || inputType === '[object File]') {
console.log('Loading/decoding input', input);
wal.load(input, {
Expand Down Expand Up @@ -87,7 +92,7 @@ function resampler(input, targetSampleRate, oncomplete) {
for (var i = 0; i < resampeledBuffer.numberOfChannels; i++) {
audioData.channelData[i] = resampeledBuffer.getChannelData(i);
}
WavEncoder.encode(audioData).then(function(buffer) {
WavEncoder.encode(audioData, { float: false, bitDepth: targetBitDepth }).then(function(buffer) {
var blob = new Blob([buffer], {
type: "audio/wav"
});
Expand Down