Arithmetic coding in Fedora libjpeg (bug #639531)

[Mukund Sivaraman]

Hi all

In reply to Gregory Maxwell:
>> It's well known around the Internet that to achieve compatibility you
>> should be conservative in what you send and liberal in what you
>> accept. Applied to JPEG: Use only Huffman coding when encoding ?
>> except maybe if you know that all recipients can handle arithmetic
>> coding ? but support both encodings when decoding.

>Absolutely. This is an excellent argument and I think is sufficient to
>justify the inclusion alone.

Thank you everyone for the replies. I did not know earlier that Fedora
was switching to libjpeg-turbo.  I have created a new bug now:

https://bugzilla.redhat.com/show_bug.cgi?id=639672
Add support for decoding arithmetic coded files in libjpeg-turbo

It contains a patch against upstream libjpeg-turbo HEAD, and the patch
has been submitted upstream too:

https://sourceforge.net/tracker/?func=detail&aid=3080268&group_id=303195&atid=1278160

This patch has been tested against some arithmetic coded images.

I wish libjpeg-turbo also accepts to include creating arithmetic coded
images too, as the project is not really going to affect creation of
such images if an application wants to do so.  But this can be saved
for another argument, and doesn't stand in the way of decode support.

		Mukund