All I want to do is play a WAV at random pitches in my Universal App. If there is a more straight forward way to do this than needed SharpDX tell me!
private void PlayTone(float randomPitch)
{
var xAudio = new XAudio2();
var masteringVoice = new MasteringVoice(xAudio);
var nativeFileStream = new NativeFileStream("Assets/440tone2.wav", NativeFileMode.Open, NativeFileAccess.Read, NativeFileShare.Read);
var stream = new SoundStream(nativeFileStream);
var waveFormat = stream.Format;
var buffer = new AudioBuffer
{
Stream = stream.ToDataStream(),
AudioBytes = (int)stream.Length,
Flags = BufferFlags.EndOfStream
};
var sourceVoice = new SourceVoice(xAudio, waveFormat, true);
sourceVoice.SubmitSourceBuffer(buffer, stream.DecodedPacketsInfo);
// sourceVoice.SetFrequencyRatio(200.0f);
sourceVoice.Start();
}
I had to switch these around
sourceVoice.SubmitSourceBuffer(buffer, stream.DecodedPacketsInfo);
sourceVoice.SetFrequencyRatio(200.0f);
Related
I am using Microsoft Azure Text To Speech with Unity. But there will be broken sounds at the beginning and end of the playing sound. Is this normal, or result.AudioData is broken. Below is the code.
public AudioSource audioSource;
void Start()
{
SynthesisToSpeaker("你好世界");
}
public void SynthesisToSpeaker(string text)
{
var config = SpeechConfig.FromSubscription("[redacted]", "southeastasia");
config.SpeechSynthesisLanguage = "zh-CN";
config.SpeechSynthesisVoiceName = "zh-CN-XiaoxiaoNeural";
// Creates a speech synthesizer.
// Make sure to dispose the synthesizer after use!
SpeechSynthesizer synthesizer = new SpeechSynthesizer(config, null);
Task<SpeechSynthesisResult> task = synthesizer.SpeakTextAsync(text);
StartCoroutine(CheckSynthesizer(task, config, synthesizer));
}
private IEnumerator CheckSynthesizer(Task<SpeechSynthesisResult> task,
SpeechConfig config,
SpeechSynthesizer synthesizer)
{
yield return new WaitUntil(() => task.IsCompleted);
var result = task.Result;
// Checks result.
string newMessage = string.Empty;
if (result.Reason == ResultReason.SynthesizingAudioCompleted)
{
var sampleCount = result.AudioData.Length / 2;
var audioData = new float[sampleCount];
for (var i = 0; i < sampleCount; ++i)
{
audioData[i] = (short)(result.AudioData[i * 2 + 1] << 8
| result.AudioData[i * 2]) / 32768.0F;
}
// The default output audio format is 16K 16bit mono
var audioClip = AudioClip.Create("SynthesizedAudio", sampleCount,
1, 16000, false);
audioClip.SetData(audioData, 0);
audioSource.clip = audioClip;
audioSource.Play();
}
else if (result.Reason == ResultReason.Canceled)
{
var cancellation = SpeechSynthesisCancellationDetails.FromResult(result);
}
synthesizer.Dispose();
}
The default audio format is Riff16Khz16BitMonoPcm, which has a riff header in the beginning of result.AudioData. If you pass the audioData to audioClip, it will play the header, then you hear some noise.
You can set the format to a raw format without header by speechConfig.SetSpeechSynthesisOutputFormat(SpeechSynthesisOutputFormat.Raw16Khz16BitMonoPcm);, see this sample for details.
I'm trying to broadcast captured mic audio across a websocket. I can see the buffer array is being sent, and the array has actual valid data but the receiving client side cannot hear it. I'm pretty sure my playback function is correct, because I can generate white noise by filling an array with random numbers and using the playback function to hear it. I'm thinking maybe the audio it's broadcasting is too quiet to hear, because the numbers generated in the array are seem to mostly be in the .000### range. Any ideas? Capturing mic audio and broadcasting it seems to be over complicated... :/
//broadcasting side
navigator.mediaDevices.getUserMedia({audio: true,video: false}) // request cam
.then(stream => {
vid.srcObject = stream;
context = new AudioContext();
var source = context.createMediaStreamSource(stream);
var processor = context.createScriptProcessor(1024, 2, 2);
source.connect(processor);
processor.connect(context.destination);
processor.onaudioprocess = function(e) {
audiodata = e.inputBuffer.getChannelData(1);
socket.send(JSON.stringify({sound: audiodata, to: to, from: '$username', text:''}));
};
return vid.play(); // returns a Promise
});
//receiving side object to array
if(typeof (message.sound) != "undefined"){
//$('#video_stream_btn').trigger('click');
var json_sound = message.sound;
var array_sound = [];
for(var i in json_sound){
array_sound.push([i, json_sound [i]]);
}
if(typeof(context) == 'undefined'){
context = new AudioContext();
}
play_sound(array_sound, context);
return;
}
// receiving side play sound function
function play_sound(raw,context){
//alert(raw.length);
var audioBuffer = context.createBuffer(1, raw.length, context.sampleRate);
audioBuffer.getChannelData(0).set(raw);
var source = context.createBufferSource();
source.buffer = audioBuffer;
source.connect(context.destination);
source.start(0);
}
For anyone out there trying to figure this out. I ended up encoding it to an int16array, then sent it across the socket, where the client encoded it back into a float32 array and passed it to the play_sound function. I basically just stole a bunch of stuff off stackoverflow and faked it until I made it, cause I'm not that smart :)
capturing mic and converting to int16array, then sending it across the socket
navigator.mediaDevices.getUserMedia({audio: {sampleSize: 16, channelCount: 2},video: true}) // request cam
.then(stream => {
vid.srcObject = stream; // don't use createObjectURL(MediaStream)
context = new AudioContext();
var source = context.createMediaStreamSource(stream);
var processor = context.createScriptProcessor(1024, 2, 2);
source.connect(processor);
processor.connect(context.destination);
processor.onaudioprocess = function(e) {
// Do something with the data, i.e Convert this to WAV
audiodata = new Int16Array(convertFloat32ToInt16(e.inputBuffer.getChannelData(0)));
console.log(audiodata);
socket.send(JSON.stringify({sound: audiodata, to: to, from: '$username', text:''}));
};
return vid.play(); // returns a Promise
});
relevant function for converting captured mic to int16array:
function convertFloat32ToInt16(buffer){
l = buffer.length;
buf = new Int16Array(l);
while (l--)
{
buf[l] = Math.min(1, buffer[l])*0x7FFF;
}
return buf.buffer;
}
receiving client side json object to int16array, then int16array back to float32array:
if(typeof (message.sound) != "undefined"){
//$('#video_stream_btn').trigger('click');
//var json_sound = message.sound;
if(typeof(context) == 'undefined'){
context = new AudioContext();
}
sound_array = [];
for (i in message.sound)
{
sound_array[i] = (message.sound [i]);
}
//sound_array16 = new Int16Array(sound_array);
sound_array32 = int16ToFloat32(sound_array);
play_sound(sound_array32, context);
return;
}
relevant receiving side int16array to float32array function:
function int16ToFloat32(inputArray) {
let int16arr = new Int16Array(inputArray)
var output = new Float32Array(int16arr.length);
for (var i = 0; i < int16arr.length; i++) {
var int = int16arr[i];
var float = (int >= 0x8000) ? -(0x10000 - int) / 0x8000 : int / 0x7FFF;
output[i] = float;
}
return output;
}
I have a website hosted by Azure that includes a Web API which I'm using to develop an android app. I'm trying to upload a media file to the server where it's encoded by a media encoder and saved to a path. The encoder library is called "Media Toolkit" which I found here : https://www.nuget.org/packages/MediaToolkit/1.0.0.3
My server side code looks like this:
[HttpPost]
[Route("upload")]
public async Task<HttpResponseMessage> Upload(uploadFileModel model)
{
var result = new HttpResponseMessage(HttpStatusCode.OK);
if (ModelState.IsValid)
{
string thumbname = "";
string resizedthumbname = Guid.NewGuid() + "_yt.jpg";
string FfmpegPath = Encoding_Settings.FFMPEGPATH;
string tempFilePath = Path.Combine(HttpContext.Current.Server.MapPath("~/video"), model.fileName);
string pathToFiles = HttpContext.Current.Server.MapPath("~/video");
string pathToThumbs = HttpContext.Current.Server.MapPath("~/contents/member/" + model.username + "/thumbs");
string finalPath = HttpContext.Current.Server.MapPath("~/contents/member/" + model.username + "/flv");
string resizedthumb = Path.Combine(pathToThumbs, resizedthumbname);
var outputPathVid = new MediaFile { Filename = Path.Combine(finalPath, model.fileName) };
var inputPathVid = new MediaFile { Filename = Path.Combine(pathToFiles, model.fileName) };
int maxWidth = 380;
int maxHeight = 360;
var namewithoutext = Path.GetFileNameWithoutExtension(Path.Combine(pathToFiles, model.fileName));
thumbname = model.VideoThumbName;
string oldthumbpath = Path.Combine(pathToThumbs, thumbname);
var fileName = model.fileName;
try
{
File.WriteAllBytes(tempFilePath, model.data);
}
catch (Exception e)
{
Console.WriteLine(e.Message);
}
using (var engine = new Engine())
{
engine.GetMetadata(inputPathVid);
// Saves the frame located on the 15th second of the video.
var outputPathThumb = new MediaFile { Filename = Path.Combine(pathToThumbs, thumbname + ".jpg") };
var options = new ConversionOptions { Seek = TimeSpan.FromSeconds(0), CustomHeight = 360, CustomWidth = 380 };
engine.GetThumbnail(inputPathVid, outputPathThumb, options);
}
Image image = Image.FromFile(Path.Combine(pathToThumbs, thumbname + ".jpg"));
//var ratioX = (double)maxWidth / image.Width;
//var ratioY = (double)maxHeight / image.Height;
//var ratio = Math.Min(ratioX, ratioY);
var newWidth = (int)(maxWidth);
var newHeight = (int)(maxHeight);
var newImage = new Bitmap(newWidth, newHeight);
Graphics.FromImage(newImage).DrawImage(image, 0, 0, newWidth, newHeight);
Bitmap bmp = new Bitmap(newImage);
bmp.Save(Path.Combine(pathToThumbs, thumbname + "_resized.jpg"));
//File.Delete(Path.Combine(pathToThumbs, thumbname));
using (var engine = new Engine())
{
var conversionOptions = new ConversionOptions
{
VideoSize = VideoSize.Hd720,
AudioSampleRate = AudioSampleRate.Hz44100,
VideoAspectRatio = VideoAspectRatio.Default
};
engine.GetMetadata(inputPathVid);
engine.Convert(inputPathVid, outputPathVid, conversionOptions);
}
File.Delete(tempFilePath);
Video_Struct vd = new Video_Struct();
vd.CategoryID = 0; // store categoryname or term instead of category id
vd.Categories = "";
vd.UserName = model.username;
vd.Title = "";
vd.Description = "";
vd.Tags = "";
vd.Duration = inputPathVid.Metadata.Duration.ToString();
vd.Duration_Sec = Convert.ToInt32(inputPathVid.Metadata.Duration.Seconds.ToString());
vd.OriginalVideoFileName = model.fileName;
vd.VideoFileName = model.fileName;
vd.ThumbFileName = thumbname + "_resized.jpg";
vd.isPrivate = 0;
vd.AuthKey = "";
vd.isEnabled = 1;
vd.Response_VideoID = 0; // video responses
vd.isResponse = 0;
vd.isPublished = 1;
vd.isReviewed = 1;
vd.Thumb_Url = "none";
//vd.FLV_Url = flv_url;
vd.Embed_Script = "";
vd.isExternal = 0; // website own video, 1: embed video
vd.Type = 0;
vd.YoutubeID = "";
vd.isTagsreViewed = 1;
vd.Mode = 0; // filter videos based on website sections
//vd.ContentLength = f_contentlength;
vd.GalleryID = 0;
long videoid = VideoBLL.Process_Info(vd, false);
return result;
}
else
{
throw new HttpResponseException(Request.CreateResponse(HttpStatusCode.NotAcceptable, "This request is not properly formatted"));
}
}
When the debugger hits the line using (var engine = new Engine()) I get 500 internal server error thrown. I don't get this error testing it on the iis server. Since it works fine on my local server and not on the azure hosted server, I figured it had to do with the Azure service rather than an error in my code. If so is the case then how would I be able to get around this issue? I don't want to use azure blob storage as it would require a lot of changes to my code. Does anyone have any idea what might be the issue.
Any helpful suggestions are appreciated.
Server.MapPath works differently on Azure WebApps - change to:
string pathToFiles = HttpContext.Current.Server.MapPath("~//video");
Also, see this SO post for another approach.
I have a template PDF file, and I want to replace some marker strings to generate new PDF files and save them. What's the best/simplest way to do this? I don't need to add graphics or anything fancy, just a simple text replacement, so I don't want anything too complicated.
Thanks!
Edit: Just found HummusJS, I'll see if I can make progress and post it here.
I found this question by searching, so I think it deserves the answer. I found the answer by BrighTide here: https://github.com/galkahana/HummusJS/issues/71#issuecomment-275956347
Basically, there is this very powerful Hummus package which uses library written in C++ (crossplatform of course). I think the answer given in that github comment can be functionalized like this:
var hummus = require('hummus');
/**
* Returns a byteArray string
*
* #param {string} str - input string
*/
function strToByteArray(str) {
var myBuffer = [];
var buffer = new Buffer(str);
for (var i = 0; i < buffer.length; i++) {
myBuffer.push(buffer[i]);
}
return myBuffer;
}
function replaceText(sourceFile, targetFile, pageNumber, findText, replaceText) {
var writer = hummus.createWriterToModify(sourceFile, {
modifiedFilePath: targetFile
});
var sourceParser = writer.createPDFCopyingContextForModifiedFile().getSourceDocumentParser();
var pageObject = sourceParser.parsePage(pageNumber);
var textObjectId = pageObject.getDictionary().toJSObject().Contents.getObjectID();
var textStream = sourceParser.queryDictionaryObject(pageObject.getDictionary(), 'Contents');
//read the original block of text data
var data = [];
var readStream = sourceParser.startReadingFromStream(textStream);
while(readStream.notEnded()){
Array.prototype.push.apply(data, readStream.read(10000));
}
var string = new Buffer(data).toString().replace(findText, replaceText);
//Create and write our new text object
var objectsContext = writer.getObjectsContext();
objectsContext.startModifiedIndirectObject(textObjectId);
var stream = objectsContext.startUnfilteredPDFStream();
stream.getWriteStream().write(strToByteArray(string));
objectsContext.endPDFStream(stream);
objectsContext.endIndirectObject();
writer.end();
}
// replaceText('source.pdf', 'output.pdf', 0, /REPLACEME/g, 'My New Custom Text');
UPDATE:
The version used at the time of writing an example was 1.0.83, things might change recently.
UPDATE 2:
Recently I got an issue with another PDF file which had a different font. For some reason the text got split into small chunks, i.e. string QWERTYUIOPASDFGHJKLZXCVBNM1234567890- got represented as -286(Q)9(WER)24(T)-8(YUIOP)116(ASDF)19(GHJKLZX)15(CVBNM1234567890-)
I had no idea what else to do rather than make up a regex.. So instead of this one line:
var string = new Buffer(data).toString().replace(findText, replaceText);
I have something like this now:
var string = Buffer.from(data).toString();
var characters = REPLACE_ME;
var match = [];
for (var a = 0; a < characters.length; a++) {
match.push('(-?[0-9]+)?(\\()?' + characters[a] + '(\\))?');
}
string = string.replace(new RegExp(match.join('')), function(m, m1) {
// m1 holds the first item which is a space
return m1 + '( ' + REPLACE_WITH_THIS + ')';
});
Building on Alex's (and other's) solution, I noticed an issue where some non-text data were becoming corrupted. I tracked this down to encoding/decoding the PDF text as utf-8 instead of as a binary string. Anyways here's a modified solution that:
Avoids corrupting non-text data
Uses streams instead of files
Allows multiple patterns/replacements
Uses the MuhammaraJS package which is a maintained fork of HummusJS (should be able to swap in HummusJS just fine as well)
Is written in TypeScript (feel free to remove the types for JS)
import muhammara from "muhammara";
interface Pattern {
searchValue: RegExp | string;
replaceValue: string;
}
/**
* Modify a PDF by replacing text in it
*/
const modifyPdf = ({
sourceStream,
targetStream,
patterns,
}: {
sourceStream: muhammara.ReadStream;
targetStream: muhammara.WriteStream;
patterns: Pattern[];
}): void => {
const modPdfWriter = muhammara.createWriterToModify(sourceStream, targetStream, { compress: false });
const numPages = modPdfWriter
.createPDFCopyingContextForModifiedFile()
.getSourceDocumentParser()
.getPagesCount();
for (let page = 0; page < numPages; page++) {
const copyingContext = modPdfWriter.createPDFCopyingContextForModifiedFile();
const objectsContext = modPdfWriter.getObjectsContext();
const pageObject = copyingContext.getSourceDocumentParser().parsePage(page);
const textStream = copyingContext
.getSourceDocumentParser()
.queryDictionaryObject(pageObject.getDictionary(), "Contents");
const textObjectID = pageObject.getDictionary().toJSObject().Contents.getObjectID();
let data: number[] = [];
const readStream = copyingContext.getSourceDocumentParser().startReadingFromStream(textStream);
while (readStream.notEnded()) {
const readData = readStream.read(10000);
data = data.concat(readData);
}
const pdfPageAsString = Buffer.from(data).toString("binary"); // key change 1
let modifiedPdfPageAsString = pdfPageAsString;
for (const pattern of patterns) {
modifiedPdfPageAsString = modifiedPdfPageAsString.replaceAll(pattern.searchValue, pattern.replaceValue);
}
// Create what will become our new text object
objectsContext.startModifiedIndirectObject(textObjectID);
const stream = objectsContext.startUnfilteredPDFStream();
stream.getWriteStream().write(strToByteArray(modifiedPdfPageAsString));
objectsContext.endPDFStream(stream);
objectsContext.endIndirectObject();
}
modPdfWriter.end();
};
/**
* Create a byte array from a string, as muhammara expects
*/
const strToByteArray = (str: string): number[] => {
const myBuffer = [];
const buffer = Buffer.from(str, "binary"); // key change 2
for (let i = 0; i < buffer.length; i++) {
myBuffer.push(buffer[i]);
}
return myBuffer;
};
And then to use it:
/**
* Fill a PDF with template data
*/
export const fillPdf = async (sourceBuffer: Buffer): Promise<Buffer> => {
const sourceStream = new muhammara.PDFRStreamForBuffer(sourceBuffer);
const targetStream = new muhammara.PDFWStreamForBuffer();
modifyPdf({
sourceStream,
targetStream,
patterns: [{ searchValue: "home", replaceValue: "emoh" }], // TODO use actual patterns
});
return targetStream.buffer;
};
There is another Node.js Package asposepdfcloud, Aspose.PDF Cloud SDK for Node.js. You can use it to replace text in your PDF document conveniently. Its free plan offers 150 credits monthly. Here is sample code to replace text in PDF document, don't forget to install asposepdfcloud first.
const { PdfApi } = require("asposepdfcloud");
const { TextReplaceListRequest }= require("asposepdfcloud/src/models/textReplaceListRequest");
const { TextReplace }= require("asposepdfcloud/src/models/textReplace");
// Get App key and App SID from https://aspose.cloud
pdfApi = new PdfApi("xxxxx-xxxxx-xxxx-xxxxxxxxxxx", "xxxxxxxxxxxxxxxxxxxxxb");
var fs = require('fs');
const name = "02_pages.pdf";
const remoteTempFolder = "Temp";
//const localTestDataFolder = "C:\\Temp";
//const path = remoteTempFolder + "\\" + name;
//var data = fs.readFileSync(localTestDataFolder + "\\" + name);
const textReplace= new TextReplace();
textReplace.oldValue= "origami";
textReplace.newValue= "aspose";
textReplace.regex= false;
const textReplace1= new TextReplace();
textReplace1.oldValue= "candy";
textReplace1.newValue= "biscuit";
textReplace1.regex= false;
const trr = new TextReplaceListRequest();
trr.textReplaces = [textReplace,textReplace1];
// Upload File
//pdfApi.uploadFile(path, data).then((result) => {
// console.log("Uploaded File");
// }).catch(function(err) {
// Deal with an error
// console.log(err);
//});
// Replace text
pdfApi.postDocumentTextReplace(name, trr, null, remoteTempFolder).then((result) => {
console.log(result.body.code);
}).catch(function(err) {
// Deal with an error
console.log(err);
});
P.S: I'm developer evangelist at aspose.
I have the below code to play a particular sound loaded into a buffer.
sound1.gainNode = context.createGain();
sound1.source = context.createBufferSource();
sound1.source.buffer = soundBuffers[num];
sound1.source.connect(sound1.gainNode);
sound1.gainNode.connect(context.destination);
sound1.source.looping = true;
sound1.source.start(0);
Here's how I call the change volume method:
<input type="range" min="0" max="100" value="70" id="playBtn1_vol" onchange="changeVolume(this,sound1Gain)" style="display:none">
Here's the change volume method:
function changeVolume = function(element,soundNo){
var volume = element.value;
var fraction = parseInt(element.value) / parseInt(element.max);
// Using an x^2 progression as it gives a better sound than linear.
soundNo.gainNode.gain.value = fraction * fraction;
};
Before I tried to get the volume working using gain, it was playing just fine but now its broken and I can't find what's wrong with it. If anyone could point me in the right direction it would be very much appreciated.
Here's sample code (js) which should help you out. Reference
var VolumeSample = {
};
// Gain node needs to be mutated by volume control.
VolumeSample.gainNode = null;
VolumeSample.play = function() {
if (!context.createGain)
context.createGain = context.createGainNode;
this.gainNode = context.createGain();
var source = context.createBufferSource();
source.buffer = BUFFERS.techno;
// Connect source to a gain node
source.connect(this.gainNode);
// Connect gain node to destination
this.gainNode.connect(context.destination);
// Start playback in a loop
source.loop = true;
if (!source.start)
source.start = source.noteOn;
source.start(0);
this.source = source;
};
VolumeSample.changeVolume = function(element) {
var volume = element.value;
var fraction = parseInt(element.value) / parseInt(element.max);
// Let's use an x*x curve (x-squared) since simple linear (x) does not
// sound as good.
this.gainNode.gain.value = fraction * fraction;
};
VolumeSample.stop = function() {
if (!this.source.stop)
this.source.stop = source.noteOff;
this.source.stop(0);
};
VolumeSample.toggle = function() {
this.playing ? this.stop() : this.play();
this.playing = !this.playing;
};
this renders web audio using a volume widget - just update mp3 with path to an actual file or some URL pointing to such
<html>
<head>
<title>render audio with volume control</title>
</head>
<body>
<p>Volume</p>
<input id="volume" type="range" min="0" max="1" step="0.1" value="0.5"/>
<script>
var audio_context = null;
var gain_node = null;
window.AudioContext = window.AudioContext || window.webkitAudioContext;
audio_context = new AudioContext();
gain_node = audio_context.createGain(); // Declare gain node
gain_node.connect(audio_context.destination); // Connect gain node to speakers
function render_audio() {
var request = new XMLHttpRequest();
var audio_url = "put_your_music_file_here.mp3";
request.open('GET', audio_url, true); // loading local file for now
request.responseType = 'arraybuffer';
// Decode asynchronously
request.onload = function() {
audio_context.decodeAudioData(request.response, function(buffer) {
stored_buffer = buffer; // store buffer for replay later
var source = audio_context.createBufferSource(); // creates a sound source
source.buffer = buffer; // tell the source which sound to play
source.connect(gain_node); // connect source to speakers
source.start(0); // play the source now
});
};
request.send();
}
// --- 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);
});
// init
render_audio();
</script>
<body onkeypress="render_audio()">
<button onclick="render_audio()">play_again</button>
</body>
</html>
I resolved this issue, I think it was to do with the ordering of the lines or the labels or something. I had this:
sound1.gainNode = context.createGain();
sound1.source = context.createBufferSource();
sound1.source.buffer = soundBuffers[num];
sound1.source.connect(sound1.gainNode);
sound1.gainNode.connect(context.destination);
sound1.source.looping = true;
sound1.source.start(0);
I updated it to this:
source1 = context.createBufferSource();
gain1 = context.createGain();
gain1.gain.value=parseFloat(document.getElementById('playBtn'+num+'_vol').value);our currently playing sound.
source1.buffer = soundBuffers[num];
source1.connect(gain1);
gain1.connect(context.destination);
source1.looping = true;
source1[source1.start ? 'start' : 'noteOn'](0);
And now it works. Might have been a rookie mistake, but hopefully this'll help someone else starting out with Web Audio.