AudioEngine's getDuration method always returns -1

[netunlimited]

Tested on iOS and on Android, with MP3 files.

Code:

auto snd = cocos2d::experimental::AudioEngine::play2d(filename);

float duration = cocos2d::experimental::AudioEngine::getDuration(snd);


[liuyi]

Maybe the filename is wrong path, AudioEngine is works fine in my device. IOS and ANDROID

[netunlimited]

I don't think it's a filename issue - the audio plays properly. Also the setFinishCallback method works as expected on the same file.
getDuration just returns only -1.000000

Here's someone else mentioning the same problem:
http://discuss.cocos2d-x.org/t/getting-duration-of-an-audio-file/4194/7

[netunlimited]

Here's one of the mp3 files I'm using. I couldn't upload it here so I've put it on Wetransfer ( expires after 7 days).
http://we.tl/UTu1aTxyZH

[piotrros]

I'm using ogg files and getDuration for first few frames returns indeed -1 and later it returns correct number.

[netunlimited]

Interesting info @piotrros, I wonder if that is intended behaviour (probably not since this issue is now filed as "bug").

[rh101]

It may have something to do with cocos2d::experimental::AudioEngine being out of sync with OpenAL, as described in this issue I recently submitted:

#15419

For the first few loops after play2d is called, the sound isn't actually playing yet in OpenAL, but once the OpenAL status is AL_PLAYING (I think this is the right state, can't verify at the moment), then a call to getDuration() will return the correct value.