[theora-dev] [OT] Just saying hi!

Mike Melanson melanson at pcisys.net
Thu Feb 27 13:46:54 PST 2003

On Thu, 27 Feb 2003, Mike Melanson wrote:

> But now I seriously think that they could be predicted as they are
> decoded. The coefficients necessary for prediction have already been
> unpacked when it is time to unpack a given DC coeff. These 2 tasks
> (unpacking DC, then predicting) could probably be effectively combined
> (not done in the original VP3 source).

        For anyone following along, I should probably note that the above
is infeasible. I thought about it some more and remembered that the
fragments are decoded in a very funky pattern which would not lend itself
to DC prediction in the same phase of the decode process.

        However, since there would be, e.g., 1800 DC coeffs in a 320x240
image, for a grand total of 3600 bytes, would it be reasonable for them
all to be in cache just after they were unpacked? Then, all of the
prediction could be calculated in one go, as I think Christoph was getting


	-Mike Melanson

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