IE 9 and 10 yield unexpected and inconsistent MediaError's

Question

We have a set of HTML blocks -- say around 50 of them -- which are iteratively parsed and have Audio objects dynamically added:

var SomeAudioWrapper = function(name) {

  this.internal_player = new Audio();

  this.internal_player.src = this.determineSrcFromName(name);
     // ultimately an MP3

  this.play = function() {
    if (someOtherConditionsAreMet()) {
      this.internal_player.play();
    }
  }

}

Suppose we generate about 40 to 80 of these on page load, but always the same set for a particular configuration. In all browsers tested, this basic strategy appears to work. The audio load and play successfully.

In IE's 9 and 10, a transient bug surfaces. On occasion, calling .play() on the inner Audio object fails. Upon inspection, the inner Audio object has a .error.code of 4 (MEDIA_ERR_SRC_NOT_SUPPORTED). The file's .duration shows NaN.

However, this only happens occasionally, and to some random subset of the audio files. E.g., usually file_abc.mp3 plays, but sometimes it generates the error. The network monitor shows a successful download in either case. And attempting to reload the file via the console also fails -- and no requests appears in IE's network monitor:

var a = new Audio();
a.src = "the_broken_file.mp3";
a.play(); // fails
a.error.code; // 4

Even appending a query value fails to refetch the audio or trigger any network requests:

var a = new Audio();
a.src = "the_broken_file.mp3?v=12345";
a.play(); // fails
a.error.code; // 4

However, attempting the load the broken audio file in a new tab using the same code works: the "unsupported src" plays perfectly.

Are there any resource limits we could be hitting? (Maybe the "unsupported" audio finishes downloading late?) Are there any known bugs? Workarounds?

I think we can pretty easily detect when a file fails. For other compatibility reasons we run a loop to check audio progress and completion stats to prevent progression through the app (an assessment) until the audio is complete. We could easily look for .error values -- but if we find one, what do we do about it!?

Addendum: I just found a related question (IE 9/10/11 sound file limit) that suggests there's an undocumented limit of 41 -- not sure whether that's a limit of "41 requests for audio files", "41 in-memory audio objects", or what. I have yet to find any M$ documentation on the matter -- or known solutions.

Answer 1

Have you seen these pages on the audio file limits within IE? These are specific to Sound.js, but the information may be applicable to your issue:

https://github.com/CreateJS/SoundJS/issues/40 ...

Possible solution as mentioned in the last comment: "control the maximum number of audio tags depending on the platform and reuse these instead of recreating them"

Additional Info: http://community.createjs.com/kb/faq/soundjs-faq (see the section entitled “I load a lot of sounds, why am running into errors in Internet Explorer?”)