XpkL2XZ

This is an LZMA2-based sub-library for XPK.  LZMA2 is an updated
version of LZMA (Lempel-Ziv-Markov) which in turn is based on the
popular LZ77 algorithm.

LZMA2 is usually found within the XZ container format, which is
effectively what this packer is using.

Compression modes (IMPORTANT!)
==============================

Modes 1-79 and 100 are recognised.  80-99 should be treated as
reserved (the compression parameters for these are undefined).

The first digit of the mode is the amount of compression, from 0-7.

Extra filters are used depending on the last digit of the mode:
x0 - no filters
x1 - delta with distance 1
x2 - delta with distance 2
x3 - delta with distance 3
x4 - delta with distance 4
x9 - PowerPC

Modes ending 5-8 are also using the PowerPC filter, but may not
do so in future.

Mode 100 is the same as mode 70, but with "extreme" set. This
gives more compression but slower.

The delta modes help compress data that changes slowly - eg, an 8-bit
sound sample might be compressed better with delta1. A photograph in
raw ARGB might compress better with delta4.  The PowerPC filter should
be used for PPC executables.  Selecting the wrong filter may have a
detrimental effect on compression ratios.

Compression is generally better than xpkLZMA, particularly if the correct
filters are deployed, however it tends to be slightly slower.

Here's some example compression for lzma.library:
As this is PPC code, modes ending in 9 are better than modes ending 0, and
the delta modes actually reduce the amount of compression attainable.

File 'lzma.library' with a size of 215924 bytes.
Type  Num Version P    CSize     CTime      CSpd     UTime      USpd  Rate
L2XZ:   0  1.1         68052      0.03   7197466      0.03   7197466  68.5
L2XZ:   1  1.1         83256      0.06   3598733      0.04   5398100  61.5
L2XZ:   2  1.1         94288      0.01  21592400      0.05   4318480  56.4
L2XZ:   3  1.1         97836      0.01  21592400      0.05   4318480  54.7
L2XZ:   4  1.1         89060      0.01  21592400      0.05   4318480  58.8
L2XZ:   9  1.1         67264      0.02  10796200      0.04   5398100  68.9
L2XZ:  10  1.1         66880      0.01  21592400      0.04   5398100  69.1
L2XZ:  11  1.1         82552      0.03   7197466      0.05   4318480  61.8
L2XZ:  12  1.1         94184      0.05   4318480      0.05   4318480  56.4
L2XZ:  13  1.1         97564      0.06   3598733      0.05   4318480  54.9
L2XZ:  14  1.1         88824      0.04   5398100      0.05   4318480  58.9
L2XZ:  19  1.1         66056      0.01  21592400      0.04   5398100  69.5
L2XZ:  20  1.1         66604      0.01  21592400      0.04   5398100  69.2
L2XZ:  21  1.1         82348      0.02  10796200      0.05   4318480  61.9
L2XZ:  22  1.1         94036      0.03   7197466      0.06   3598733  56.5
L2XZ:  23  1.1         97452      0.04   5398100      0.06   3598733  54.9
L2XZ:  24  1.1         88700      0.02  10796200      0.06   3598733  59.0
L2XZ:  29  1.1         65764      0.01  21592400      0.05   4318480  69.6
L2XZ:  30  1.1         66480      0.05   4318480      0.06   3598733  69.3
L2XZ:  31  1.1         82280      0.06   3598733      0.01  21592400  61.9
L2XZ:  32  1.1         93992      0.01  21592400      0.01  21592400  56.5
L2XZ:  33  1.1         97432      0.01  21592400      0.01  21592400  54.9
L2XZ:  34  1.1         88664      0.07   3084628      0.01  21592400  59.0
L2XZ:  39  1.1         65652      0.05   4318480      0.06   3598733  69.6
L2XZ:  40  1.1         63952      0.01  21592400      0.06   3598733  70.4
L2XZ:  41  1.1         80948      0.04   5398100      0.01  21592400  62.6
L2XZ:  42  1.1         90312      0.02  10796200      0.01  21592400  58.2
L2XZ:  43  1.1         95068      0.02  10796200      0.01  21592400  56.0
L2XZ:  44  1.1         86212      0.04   5398100      0.01  21592400  60.1
L2XZ:  49  1.1         63092      0.01  21592400      0.06   3598733  70.8
L2XZ:  50  1.1         63760      1.01    213786      0.01  21592400  70.5
L2XZ:  51  1.1         80828      1.04    207619      0.02  10796200  62.6
L2XZ:  52  1.1         90104      1.02    211690      0.02  10796200  58.3
L2XZ:  53  1.1         94868      1.02    211690      0.03   7197466  56.1
L2XZ:  54  1.1         86060      1.04    207619      0.03   7197466  60.2
L2XZ:  59  1.1         62892      1.00    215924      0.01  21592400  70.9
L2XZ:  60  1.1         63700      1.01    213786      0.01  21592400  70.5
L2XZ:  61  1.1         80752      1.04    207619      0.02  10796200  62.7
L2XZ:  62  1.1         90016      1.02    211690      0.02  10796200  58.4
L2XZ:  63  1.1         94828      1.02    211690      0.03   7197466  56.1
L2XZ:  64  1.1         86348      1.03    209634      0.03   7197466  60.1
L2XZ:  69  1.1         62836      1.01    213786      0.01  21592400  70.9
L2XZ:  70  1.1         63700      1.00    215924      0.06   3598733  70.5
L2XZ:  71  1.1         80752      1.03    209634      0.01  21592400  62.7
L2XZ:  72  1.1         90016      1.01    213786      0.01  21592400  58.4
L2XZ:  73  1.1         94828      1.01    213786      0.01  21592400  56.1
L2XZ:  74  1.1         86348      1.02    211690      0.01  21592400  60.1
L2XZ:  79  1.1         62836      1.00    215924      0.07   3084628  70.9 *
L2XZ: 100  1.1         63784      2.00    107962      0.06   3598733  70.5

LZMA: 100 52.2         63608      1.00    215924      0.02  10796200  70.6
BZP2: 100  1.7         78680      1.04    207619      0.05   4318480  63.6
GZIP: 100 50.4         77592      0.03   7197466      0.01  21592400  64.1


X1000 users
===========

I've been advised that this sub-lib is very slow when packing on an X1000.
I believe this is because lzma.library when compiled was built to use
instructions which cause an exception on the PA6T.  I have yet to find
the correct compiler switches which fix this as well as producing a working
lzma.library.


DISCLAIMER
==========

No warranty is expessed nor implied for this software.  If you compress data
using it, there is no guarantee it will be uncompressible in future.  Please
keep an uncompressed copy of any data you care about.  The author will not
take responsibility for any loss of data due to direct or indirect use of
this software.  If you don't agree to these terms, you must delete the
archive without installing it.