[BUG] Flash file JPEG decoding
Tim Olson
tim at jump.net
Tue Jun 12 13:00:45 UTC 2001
I've debugged this problem a little more. Ignoring the extraneous EOI,
SOI on the front, it appears to be a valid JFIF image. However, the
FlashJPEGDecoder (a subclass of JPEGReadWriter) is performing the Flash
tag 21 "ProcessDefineBitsJPEG2", which reads a JFIF header, parsing the
JFIF markers while looking for an EOI marker (i.e. it seems to be
expecting just a JFIF header with no JPEG image data following it).
I'm not sure what the real purpose of ProcessDefineBitsJPEG2 is, as after
it reads the JFIF header and an expected EOI, it then performs
decodeNextImageFrom:, which would then process an entire JFIF image
(including parsing all the header data from the stream again, in effect
discarding the header data previously read).
I think Andreas Raab was the person who implemented the Flash support --
Andreas, do you have any insights into what is going on in this case?
-- tim
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