sadek at ict.usc.edu
Fri Feb 10 11:41:14 PST 2006
I didn't realize that buffers of different types cannot be queued into a
source. This must be an oversight on my part. Could you point me/us to
the documentation wherein this constraint is outlined?
From: Garin Hiebert [mailto:garinh at cheesetoast.net]
Sent: Friday, February 10, 2006 11:31 AM
To: Ramy Sadek
Cc: openal-devel at opensource.creative.com
Subject: Re: [Openal-devel] AL_BYTE_OFFSET
> Implementing AL_BYTE_OFFSET leads me to some confusion. Consider 3
> files FileA, FileB and FileC, which are in differing formats, MONO8,
> MONO16 and STERO16 respectively. If these 3 files are queued into a
> buffer, what is the meaning of calls like
The files can't be concatenated into the same buffer, since they are
different formats. If placed in three separate buffers, they can't be
queued onto the same source, also because they are of different formats
(source queues can only have one format).
> alSourcei(source, AL_BYTE_OFFSET, num) ?
> Depending on the order of the files, <num> bytes represents a
> different number of samples (and therefore different amounts of time).
> Specifically, <num> refers to twice as many samples in the MONO8
> FileA as it does in the 16-bit files FileB and FileC.
AL_BYTE_OFFSET is always in bytes, so there wouldn't be any confusion if
you could do what you describe. Such confusion would exist with
AL_SAMPLE_OFFSET, but since the formats can't be mixed it's not a
> Furthermore, if implementations are using longer words to represent
> samples internally (e.g. 32 bit float samples), the meaning of
> AL_BYTE_OFFSET is even less clear.
The application can use AL_SAMPLE_OFFSET to avoid this type of issue.
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