ExtAudioFileDispose Error

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Joined: Sun Aug 06, 2006 5:13 pm
Location: Denver, CO, USA

ExtAudioFileDispose Error

Post by teece »

I added a comment to this bug, but I thought I'd post a message here, too, as I spent awhile reading the forums looking for this.

First off, thanks for the great product! I spent an entire day looking for something like Max, most of them costing $20 to $40, and none of them were as nice as the free and GPL'd Max, which I stumbled upon last, and by accident.

I have some files encoded to AAC/M4A, MPEG-4, whatever we're calling it these days. I did not encode them. I believe they are all encoded by the same software, but I don't know what that software is (they all share the same source).

All of these AAC files fail when any attempt at conversion is made, with the an error of ExtAudioFileDispose, see the bug linked above.

I may have found something that might be the problem, and I did find a (kludgey and annoying) work around.

What they all seem to have in common is this: in a "Get Info" window in the Finder, under the "More Info->Codecs" section, in addition to listing AAC, they also list MPEG-4 ODSM, MPEG4-SDSM. My other m4a files have AAC as the only codec there (these are ones I encoded with iTunes).

If I open one of these 3-codec AAC files in Quicktime Pro, goto the "Properties" pane, and delete those two tracks/layers/containers/whatever, and then export the file as an MP4 movie (with pass-through as the encoding, which I believe just puts the already-encoded AAC data into a new container, so as to not take the quality hit of re-encoding), I can then use it regularly in Max and iTunes (but the files worked in iTunes and Quicktime before: the only problem with them is showing up in Max). That is, this "ExtAudioFileDispose" error goes away, and the file can be handled normally in Max (I happen to be converting to OGG). This is less than ideal, not only because it's manual (which was the whole point of Max: automation ;-) ), but also because QT kills all the metadata, so I'd have to key everything in again if I used this as a solution. And you also have to purchase QT Pro (well, I don't think you can do that with just QT).

I'm not certain at all that this is the only thing causing this bug, but it does seem to be the only thing causing it on my machine, and the fact that killing those tracks lets Max do its thing is a strong indicator that it might be. I don't know if those two extra tracks on the AAC file are supposed to be there, and Core Audio or Max is handling them incorrectly, or if the AAC files with those tracks are some kind of bad AAC file made by a buggy encoder.

Maybe this will help track down the bug, which is, I suspect, in CoreAudio.

If anyone knows of a painless way, on a Mac, to kill those two channels (or whatever it is they are called) that doesn't involve killing the tags and buying QT Pro or re-encoding, I'd love to hear it, as a work-around for this problem for now. Because if this is really an Apple bug in Core Audio (which it may not be), it could be a long time until we get a fix from them.
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