[Openal] noise playing ogg files using OpenAL
garinh at cheesetoast.net
Sat Sep 9 18:14:18 PDT 2006
I'd suggest two steps:
1) If your program isn't using enumeration, I'd modify it to do so and
see if the results are consistent for multiple output devices. At
minimum, your system will probably support a "Generic Hardware" and a
"Generic Software" device, which have different mixing code. If you
have a hardware-accelerated device available, then things are even
better -- you'll have another device which has a _very_ different code path.
If the problem winds up happening for only one device, that's a valuable
2) The diagnostic technique I normally use for cases like this is to
isolate a stream of bad output (one OpenAL source, to use OpenAL's
naming conventions), and dump the raw PCM data that is being placed into
the OpenAL buffers (multiple if you are streaming the data) to a file.
Then, bring that data up in Audacity, Cool Edit, or equivalent, and play
it back from there.
Barring a misunderstanding, this should tell you if this is a case of
garbage-in-garbage-out or good-data-in-garbage-out. If the data in is
bad, then trace backwards, and if the data in is good, then it would be
worth repeating the data-dump process inside a modified version of the
OpenAL library to trace where the problem is occurring.
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