Re: [Libjpeg-devel-6x] libjpeg-8 - Was: libjpeg license

[Guido V. <gu...@jp...>]

Hello Allan

> > And even v7 is fading fast into history.
> > v8 is ready here and will be released on 1-Jan-2010.
> >
> 
> Is there going to be api changes this time?

No.  That's why it was good to release v7 so that the changes can
be resolved now.  No further adaptions should be necessary for v8.
But there are of course reasons for the jump from v7 to v8:
Applications need again to be recompiled, due to extension of the
parameter master records, and there will be a format extension which
will introduce new flavors of JPEG files, similar to adding progressive
support in v6 and arithmetic support in v7.

> The libjpeg6 to 7 upgrade was complicated by the change in scaling.
> 
> jpeg-6b: Currently, the only supported scaling ratios are 1/1, 1/2, 1/4,
> and 1/8.
> jpeg-7:  Currently, the supported scaling ratios are 8/N with all N from
> 1 to 16.

It was not complicated, but people just got confused that scaling has
now been introduced also for the compression side.
The 8/N figure is for *compression*!  For decompression it is N/8 and
the old cases are a subset thereof (N=8,4,2,1).

> Also, is there a mailing list for the development of libjpeg apart from
> this one?

There is no mailing list.
I will make available pre-release versions of v8 on jpegclub.org
in some weeks (when adaptions of the Jpegcrop sample program are
finished), similar as done with v7.

Regards
Guido