decoder.txt

非常不错的jpeg压缩/解压代码,可以实现常用的JPEG压缩/解

Well, here it is the decoder source.
It takes as an input a JPG file and decodes it into a truecolor BMP.

Opposite to the encoder, it's not so optimized or clear as I wanted.
But since I received a lot of emails asking for it, here it is.

It is written long ago and since then I was quite busy learning other stuff 
and I haven't modified it as it should [Huffman decoder probably can be made
better and IDCT (the most consuming CPU part) -- should be done faster],
so don't expect a super fast decoder [though it's speed seems reasonable].
Few comments are in romanian.
Some ideas have been taken from Independent JPEG Group's JPEG software.
(IDCT routine is taken with minor modifications)

It compiles under WATCOM C (still my favourite compiler) 10.0 for DOS, and 
VISUAL C 5.0 (if you turn on optimizations in VC 5.0, make sure that the option
"assume aliasing across function calls" it's turned on for the "jpegdec.c" module).
I haven't tested it under other compilers.

I don't know when I'll have the time to make it better, but in the meantime, 
I'd like to hear from you if you make it more clear and/or faster.

You are free to modify it as you want, but it would be nice to say somewhere 
that you used ideas from these routines.

Disclaimer
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NO WARRANTY PROVIDED WITH THIS PROGRAM.
So, use it at your own risk.
It's status: freeware.

Author email: 
            [e-mail]