Release Notes
Open Source Used In AsyncOS 8.8 for Cisco Web Security Appliances
108
(jpeg_std_message_table[]) from jerror.c, and alter format_message to do
something reasonable without it. You could output the numeric value of the
message code number, for example. If you do this, you can also save a couple
more K by modifying the TRACEMSn() macros in jerror.h to expand to nothing;
you don't need trace capability anyway, right?
Portability considerations
--------------------------
The JPEG library has been written to be extremely portable; the sample
applications cjpeg and djpeg are slightly less so. This section summarizes
the design goals in this area. (If you encounter any bugs that cause the
library to be less portable than is claimed here, we'd appreciate hearing
about them.)
The code works fine on ANSI C, C++, and pre-ANSI C compilers, using any of
the popular system include file setups, and some not-so-popular ones too.
See install.txt for configuration procedures.
The code is not dependent on the exact sizes of the C data types. As
distributed, we make the assumptions that
charis at least 8 bits wide
shortis at least 16 bits wide
intis at least 16 bits wide
longis at least 32 bits wide
(These are the minimum requirements of the ANSI C standard.) Wider types will
work fine, although memory may be used inefficiently if char is much larger
than 8 bits or short is much bigger than 16 bits. The code should work
equally well with 16- or 32-bit ints.
In a system where these assumptions are not met, you may be able to make the
code work by modifying the typedefs in jmorecfg.h. However, you will probably
have difficulty if int is less than 16 bits wide, since references to plain
int abound in the code.
char can be either signed or unsigned, although the code runs faster if an
unsigned char type is available. If char is wider than 8 bits, you will need
to redefine JOCTET and/or provide custom data source/destination managers so
that JOCTET represents exactly 8 bits of data on external storage.
The JPEG library proper does not assume ASCII representation of characters.
But some of the image file I/O modules in cjpeg/djpeg do have ASCII
dependencies in file-header manipulation; so does cjpeg's select_file_type()
routine.
The JPEG library does not rely heavily on the C library. In particular, C
stdio is used only by the data source/destination modules and the error