The special focus of Release 44.18 was improved performance on 
the 68040. JPEG loading using the default HQ iDCT is now about 
30% faster on 68040 compared to earlier releases. Speed gains 
on 68060 are more modest at up to 10%. An installer was included,
too.

In short: the fastest 68k Amiga JPEG datatype got faster, again.

A performance comparison is shown below. (on A3000 with 
BFG9060@100 MHz, 3.1 ROM, CyberVision64 in HiColor, 
picture.datatype 47.15 from OS3.2.1, all datatypes at 
default settings; times in seconds measured as median over 
5 iterations with "visage nojpeg time test"):

Name                  |akjfif  |jfif    |warpjpeg|os32jpeg|
Version               |45.95   |44.18   |45.16   |47.8    |
----------------------|--------|--------|--------|--------|
APac640x480.jpg       |0.501   |0.319   |0.473   |0.382   |
BGA1024x1024.jpg      |1.568   |1.370   |1.524   |1.515   |
Casa2592x1728A.jpg    |4.713   |3.069   |4.048   |3.743   |
Casa2592x1728B.jpg    |8.376   |5.553   |7.816   |6.676   |
Goose1024x768.jpg     |2.027   |1.479   |1.884   |1.829   |
Molli512x384.jpg      |0.392   |0.267   |0.363   |0.320   |
Peacock800x600.jpg    |0.945   |0.630   |0.904   |0.762   |
Sail768x576.jpg       |0.699   |0.443   |0.643   |0.530   |
Wnmde1152x768.jpg     |1.829   |1.514   |1.721   |1.664   |
Wnmde1536x1024.jpg    |1.871   |1.227   |1.715   |1.474   |
jordan199b.jpg        |1.219   |0.743   |1.068   |0.899   |

The numbers for 68040/25 MHz are following below.
(A4000, BFG9060 in 68040 mode, Kick3.2.1, PicassoIV)

Name                  |akjfif  |jfif    |warpjpeg|os32jpeg|
Version               |45.95   |44.18   |45.16   |47.6    |
----------------------|--------|--------|--------|--------|
APac640x480.jpg       |3.541   |2.549   |3.472   |3.566   |
BGA1024x1024.jpg      |9.048   |8.245   |8.631   |9.641   |
Casa2592x1728A.jpg    |34.007  |26.946  |31.752  |36.476  |
Casa2592x1728B.jpg    |63.804  |49.727  |62.038  |65.766  |
Goose1024x768.jpg     |16.123  |13.733  |15.451  |17.822  |
Molli512x384.jpg      |2.808   |2.188   |2.704   |2.925   |
Peacock800x600.jpg    |7.152   |5.550   |7.090   |7.424   |
Sail768x576.jpg       |4.873   |3.514   |4.715   |4.874   |
Wnmde1152x768.jpg     |10.140  |11.078  |10.010  |12.858  |
Wnmde1536x1024.jpg    |13.778  |10.239  |13.095  |14.160  |
jordan199b.jpg        |8.217   |6.087   |7.905   |8.615   |


The test images, benchmarking scripts, system details and 
raw results are available at:
http://bax.comlab.uni-rostock.de/fileadmin/downloads/jpegbench.zip


The datatype is an all-in-one binary for any 68020+ Amiga.
A 68000 version (without assembly optimizations) is provided as 
well.


Changes in this release
 44.18:
 - added installer script
 - overhauled YCC to RGB conversion by avoiding multiplications such
   that it runs much faster on MC68030/68040
 - updated both HQ and fast integer iDCT algorithms with faster paths
   for some special cases that are computed as more efficient 2D iDCT 
   instead of the customary 1D separated row/column approach
 44.17:
 - fixed V42 mode (3.0/3.1 without updated picture.datatype)
 - added CPU check to 020+ version to exit cleanly on 68000/68010
 - removed FPU requirement (FPU iDCT is still optionally available
   on FPU equipped systems)
 - added minimum CPU type to version string
 44.16:
 - fixed occasionally missing rows of pixels in cases where the
   SCALE or MAXLENGTH options are active
 - prepared for additional speedup on OS3.2.1 (about 100ms per
   megapixel on 060/50 with picture.datatype 47.15)
 44.15:
 - fixed incompatibility with picture.datatype 45.17 (OS3.9BB2)
 44.14:
 - enabled arithmetic residual coding (not part of the JPEG standard
   last I checked, but there are some pictures on the internet using 
   this mode)
 - improvements to Huffman decoding functions
 - leverage V47 picture.datatype features for more performance
 - improvements to grayscale image handling


Feature overview

 - supports normal and progressive JFIFs with all its flavours
 - supports HAM output (HAM6 as well as HAM8)
 - switches to V43 mode if a picture.datatype V43 or newer is found
 - asynchronous file I/O to speedup image loading and decoding
 - utilizes WritePixelLine8() for chunky-to-planar in V42 mode
 - automatic colour quantizing of true-colour data for V42
 - can be configured to suit personal preferences
 - OS 3.5 and later support (minimum OS3.0)
 - FBlit tolerance
 - based on libjpeg-turbo
 - ASM optimizations to Huffman decoding, iDCT and color 
   transform (68020+)
 - 30 bit internal resolution for color transform functions
 - Highly accurate and fast default inverse cosine transform
   function (stock libjpeg methods still available as options)
 - AMMX optimization for Apollo Core Gold 2.7 and later
 - FPU and AMMX availability is checked before use at runtime
 - support for XMP JFIF files
 - all-in-one binary for 68020+


Tuning (see also the guide file for additional options):

 Classic 68k based Amigas
 - The old fast iDCT is still about 10% faster than the default
   on 68030/68040.
   If you care more for speed than accuracy, just type 
    makedir envarc:classes
    makedir envarc:classes/datatypes
    echo "DCT=FAST" >envarc:classes/datatypes/jfif44.prefs
   in a shell window. Alternatively, a single commandline
   call is also possible:
    setenv envarc:classes/datatypes/jfif44.prefs DCT=FAST
   
 Vampire Amigas
 - On Vampire, the default iDCT is the AMMX fast, less accurate iDCT. 
   If you'd like to have the better accuracy of the new iDCT, type 
   the following lines in a shell window:
    makedir envarc:classes
    makedir envarc:classes/datatypes
    echo "DCT=FASTGOOD" >envarc:classes/datatypes/jfif44.prefs
  alternative:
    setenv envarc:classes/datatypes/jfif44.prefs DCT=FASTGOOD

PERMISSION  UID  GID    PACKED    SIZE  RATIO METHOD CRC     STAMP     NAME
---------- ----------- ------- ------- ------ ---------- ------------ ----------
[unknown]                  258     516  50.0% -lh5- 770e Mar 25 23:25 jfifdt44.18/Classes.info
[unknown]                  265     516  51.4% -lh5- 45bb Jul 31  2021 jfifdt44.18/Classes/Datatypes-68000.info
[unknown]                50898   84696  60.1% -lh5- bf7b Jun 17 08:28 jfifdt44.18/Classes/Datatypes-68000/jfif.datatype
[unknown]                  264     516  51.2% -lh5- bd35 Jul 31  2021 jfifdt44.18/Classes/Datatypes.info
[unknown]                56561   93488  60.5% -lh5- ee46 Jun 17 08:28 jfifdt44.18/Classes/Datatypes/jfif.datatype
[unknown]                  286     342  83.6% -lh5- 540a Mar 25 23:25 jfifdt44.18/Devs/Datatypes/JFIF
[unknown]                 2111    7936  26.6% -lh5- d785 Jun 18 01:14 jfifdt44.18/Install
[unknown]                 1119    2015  55.5% -lh5- 7394 Jun 17 22:48 jfifdt44.18/Install.info
[unknown]                 7652   18588  41.2% -lh5- d893 Jun 18 08:21 jfifdt44.18/JFIFdt.guide
[unknown]                  275     514  53.5% -lh5- 25bf Mar 25 23:25 jfifdt44.18/JFIFdt.guide.info
[unknown]                 2725    6081  44.8% -lh5- bfe0 Jun 18 08:47 jfifdt44.18/JFIFdt44.readme
[unknown]               584209  584209 100.0% -lh0- 5ee1 Jun 18 08:52 jfifdt44.18/Source.lzx
[unknown]                  259     516  50.2% -lh5- 2f1b Mar 25 23:26 jfifdt44.18.info
[unknown]                  260     516  50.4% -lh5- 8934 Mar 25 23:25 jfifdt44.18/Devs.info
[unknown]                  261     516  50.6% -lh5- 551a Mar 25 23:25 jfifdt44.18/Devs/Datatypes.info
[unknown]                 1978    2279  86.8% -lh5- aa94 Mar 25 23:25 jfifdt44.18/Devs/Datatypes/JFIF.info
[unknown]                  275     514  53.5% -lh5- 67a1 Mar 25 23:25 jfifdt44.18/JFIFdt44.readme.info
---------- ----------- ------- ------- ------ ---------- ------------ ----------
 Total        17 files  709656  803758  88.3%            Jun 26 02:28