2006.04.04 02:19 "[Tiff] New OJPEG support", by Joris Van Damme

Folks,

The new tif_ojpeg.c has just been dropped into CVS. At your convinience, please test, and be merciless.

Some important notes:

• While I've no clue about your *nix makefile trouble (oops... sorry, disregard that last word), I understand that tif_ojpeg.c is optional and not included by default. You'll have to do something special to include it, and I hope you know 'cause I don't.
• The new tif_ojpeg.c does not require the old hack in LibJpeg. Don't forget to remove that hack if you used the old tif_ojpeg.c before.
• The new tif_ojpeg.c does not support TIFFTAG_JPEGCOLORMODE. If your own application level doesn't handle YCbCr and desubsampling, you may test and use tif_ojpeg.c through the tif_getimage.c layer instead. This tif_getimage.c does support YCbCr and desubsampling for planarconfig contig, not separate, but almost all tif_ojpeg images are contig anyway.
• I've not been able to test the longjump way to call LibJpeg functions... Some environments don't support longjump. This includes my own LibTiffDelphi build. Thus, I've included an alternative way of calling, triggered by the optional define LIBJPEG_ENCAP_EXTERNAL. If you define that, LibJpeg doesn't get called directly, but you have a chance to implement dedicated call encapsulators outside of tif_ojpeg.c. The use with this LIBJPEG_ENCAP_EXTERNAL is tested, but the default, direct longjump call usage without LIBJPEG_ENCAP_EXTERNAL is not. I must depend on you to do that and report any problems. Default is normal longjump, so you likely don't need to change anything.
• Please make a note of any compiler warnings you see. Even if they don't impact functionality, I'm eager to learn about them and solve them.
• Please test with all OJPEG files you have, even if you've already posted me your testfiles... I've build support for all testfiles I've received, but, still, there are different ways to use the library, and maybe I've missed one in my testing process...
• Any remark, small, big, or huge, please tell me... I aim to please.

Joris Van Damme
info@awaresystems.be
http://www.awaresystems.be/
Download your free TIFF tag viewer for windows here:
http://www.awaresystems.be/imaging/tiff/astifftagviewer.html