Databases
StackOverflow2013
Postsdbo
PODistorted sounds with Dartium and Web Audio API in Dart
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PODistorted sounds with Dartium and Web Audio API in Dart
    primarykey
    data
    text
    <p>I'm pretty new to the HTML5 audio api: I've read some of the related articles at <a href="http://www.html5rocks.com" rel="nofollow">HTML5 Rocks</a>, but it can be a little tricky flipping between Javascript and Dart at times.</p> <p>In any case, I've been experimenting with HTML5 Audio in Dart. To produce sound effects for a simple game, I created a class as follows. I created an AudioContext, loaded sound data into SoundBuffers, and when the sound needed to be played, created an AudioBufferSourceNode via which to play the data stored in the buffers:</p> <pre><code>class Sfx { AudioContext audioContext; List&lt;Map&gt; soundList; int soundFiles; Sfx() { audioContext = new AudioContext(); soundList = new List&lt;Map&gt;(); var soundsToLoad = [ {"name": "MISSILE", "url": "SFX/missile.wav"}, {"name": "EXPLOSION", "url": "SFX/explosion.wav"} ]; soundFiles = soundsToLoad.length; for (Map sound in soundsToLoad) { initSound(sound); } } bool allSoundsLoaded() =&gt; (soundFiles == 0); void initSound(Map soundMap) { HttpRequest req = new HttpRequest(); req.open('GET', soundMap["url"], true); req.responseType = 'arraybuffer'; req.on.load.add((Event e) { audioContext.decodeAudioData( req.response, (var buffer) { // successful decode print("...${soundMap["name"]} loaded..."); soundList.add({"name": soundMap["name"], "buffer": buffer}); soundFiles--; }, (var error) { print("error loading ${soundMap["name"]}"); } ); }); req.send(); } void sfx(AudioBuffer buffer) { AudioBufferSourceNode source = audioContext.createBufferSource(); source.connect(audioContext.destination, 0, 0); source.buffer = buffer; source.start(0); } void playSound(String sound) { for (Map m in soundList) { print(m); if (m["name"] == sound) { sfx(m["buffer"]); break; } } } } </code></pre> <p>(The sound effects are in a folder "SFX". Now that I look at the code, there are probably a million better ways to organise the data, but that's besides the point right now.) I am able to play sound effects by creating an instance of Sfx and calling the method playSound. </p> <p>e.g.</p> <pre><code>#import('dart:html'); #source('sfx.dart'); Sfx sfx; void main() { sfx = new Sfx(); window.on.keyUp.add((KeyboardEvent keX) { sfx.playSound("MISSILE"); }); } </code></pre> <p>(Edit: added code to play sound when a key is hit.)</p> <p>The problem is: although with the dart2js Javascript, the sound effects play as expected in Safari, when they are played in Dartium or (with the dart2js Javascript) in Chrome, they are distorted. (In Firefox, there are even worse problems!)</p> <p>Is there anything obvious that I have neglected to do or that I need to take into account? Otherwise, are there any references or tutorials, preferably in a Dart context, that might help?</p>
    singulars
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PTQuestion
    1. USRichard Ambler
    1. USRichard Ambler
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. PODistorted sounds with Dartium and Web Audio API in Dart
      1. This table or related slice is empty.
      1. VTApproveEditSuggestion
    1. COThe Dart team has a [git repo](https://github.com/dart-lang/dart-html5-samples) where they are porting the HTML5 Rocks tutorials to Dart. One of them is a port of the [Getting Started with the Web Audio API](http://www.html5rocks.com/en/tutorials/webaudio/intro/). Not sure if this is what you are after but it is [here](https://github.com/dart-lang/dart-html5-samples/blob/master/webaudio/intro/filter_sample.dart) if you want to see how they are doing it.
      singulars
      1. PODistorted sounds with Dartium and Web Audio API in Dart
      1. USscribeGriff
    2. COThanks! That sounds like a good starting point. I'll be sure to check it out.
      singulars
      1. PODistorted sounds with Dartium and Web Audio API in Dart
      1. USRichard Ambler
    3. COJust as an update: I took a look at the git repo linked above; the problem seems to lie with the audio file I was using: it was a 32 bit .wav whereas the sound in the example was 16 bit. When I saved my sound files as 16 bit .wav files, they played as expected in both Chrome and Safari...
      singulars
      1. PODistorted sounds with Dartium and Web Audio API in Dart
      1. USRichard Ambler
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload