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Has anybody out there got working sample code that synthesizes (and plays) audio using HTML5/Javascript on Mobile Safari on the iPad? I have found some examples for javascript-based sound synthesis on the web, but they all seem to work in Firefox only.

jms
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  • The JS audio samples I'm aware of work in FF, Safari, Opera .. but they don't seem to work on the iPad version of Safari. Generally I find HMTL5 support on that browser to be either sluggish or broken - at least for the features I've tried. – brainjam Sep 02 '10 at 22:42

4 Answers4

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Recently I came across this js-library, I think this is what you want -> https://github.com/oampo/Audiolet

heyoka
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    This sounds like an interesting Library; however, it only works on Firefox and some Versions of Chrome. I was looking for something that works on mobile Safari for iPad. – jms Jul 17 '11 at 10:57
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I'm answering a very old question... but modern webkit browsers now support the Web Audio API. I wrote a very simple fiddle that generates chords using sine waves. There are only 4 built-in wave forms, but you can build your own using Fourier coefficients (array of numbers). You have to generate a new oscillator object for each note. They are single use objects. By connecting multiple oscillators to the same destination, you get polyphonic sounds.

 let audio = new(window.AudioContext || window.webkitAudioContext)();
 let s1 = audio.createOscillator();
 let g1 = audio.createGain();
 s1.type = 'sine';
 s1.frequency.value = 600;
 s1.start();
 g1.gain.value = 0.5;
 g1.connect(audio.destination);
 s1.connect(g1);
John Henckel
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Here is an example that works for me on an iPad:

www.cse.usf.edu/~turnerr/sound_demo.html

You can download the files from http://www.cse.usf.edu/~turnerr/Downloads/Sound_Demo.zip

This demo is on a Unix based server. But I have not been been able to get the same code to work on an IIS server. Hoping someone can provide some help with IIS.

Rollins Turner
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    Sorry, but that doesn't help. Playing existing audio files is not the issue - I need to render new audio on the fly (e.g. sine waves) and then play it – jms Mar 20 '11 at 08:20
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You may be able to use generated data URIs of uniform length, such as 0.1 seconds. This would give you 1/10 of a second delay and you would generate that many "frames" of audio. I'm not sure entirely what formats the iPad supports, but I read it supports uncompressed WAV. Info on this file format is pretty easy to get, I remember generating WAV files a long time ago with some primitive byte manipulation methods.

Please post back with details!

Kristopher Ives
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  • I have been thinking about a similar solution. Problem is, the iPad stubbornly refuses to auto-play audio of any kind - the user would have to tap a button 10 times a second to achieve continuous audio. – jms Dec 28 '11 at 19:37
  • @jms: Interesting. I am trying to implement a synthsizer myself but with the restriction that I want to emulate instruments. So you are saying dataUri would technically work if the user taps a button? If that's true I could just generate the anticipated sound for the future assuming no further input and then replace it with a new prediction on additional input. That works for me because I only generate sound based on user input in the first place. Have you figured anything out (this is an old topic, all I know there was no progress so far in terms of support)? – thesaint Apr 27 '14 at 12:25