pnglibconf.h, allowing more of the decisions to be made internally
(pngpriv.h) during the compile. Without this, symbol prefixing is broken
under certain circumstances on ARM platforms. Now only the API parts of
the optimizations ('check' vs 'api') are exposed in the public header files
except that the new setting PNG_ARM_NEON_OPT documents how libpng makes the
decision about whether or not to use the optimizations.
For inflate, reverted previous fixes.
Added fixitxt and pngdeflate to the built programs and removed warnings
from the source code and timepng that are revealed as a result. Fixed
fixitxt when the chunk length is more than 65535 (untested, no test case).
prefixing This adds an API to set optimization options externally,
providing an alternative and general solution for the non-portable
run-time tests used by the ARM Neon code. It also makes those tests
compile and link on Android.
The order of settings vs options in pnglibconf.h is reversed to allow
settings to depend on options and options can now set (or override) the
defaults for settings.
option:
--enable-arm-neon=always will stop the run-time checks. New checks
within arm/arm_init.c will cause the code not to be compiled unless
__ARM_NEON__ is set. This should make it fail safe (if someone asks
for it on then the build will fail if it can't be done.)
Fixed ALIGNED_MEMORY support.
READ_GAMMA. Prior to 1.6.0 switching off READ_GAMMA did unpredictable things
to the interfaces that use it (specifically, png_do_background in 1.4 would
simply display composite for grayscale images but do composition
with the incorrect arithmetic for color ones). In 1.6 the semantic
of -DPNG_NO_READ_GAMMA is changed to simply disable any interface that
depends on it; this obliges people who set it to consider whether they
really want it off if they happen to use any of the interfaces in
question (typically most users who disable it won't).
management system (CMS). In practice it is not possible to obtain cHRM
information reliably using just the end-point tags because they do not exist
in the vast majority of profiles. Instead it is necessary to run the endpoints
through the ICC colorimetric intent transform (as described in the v4
spec). Since this is likely to be too much code inside libpng for too
little gain (it implies a fairly complete CMS implementation) the code
has been changed to allow an external CMS to be used. This code is
temporarily disabled until a suitable set of test cases using one or more
external CMS implementations have been implemented.
png_set_keep_unknown_chunks() to be turned off if not required and causes
both read and write to behave appropriately (on read this is only possible
if the user callback is used to handle unknown chunks). The change
also removes the support for storing unknown chunks in the info_struct
if the only unknown handling enabled is via the callback, allowing libpng
to be configured with callback reading and none of the unnecessary code.
control of the unknown handling, corrects the pre-existing bug where
the per-chunk 'keep' setting is ignored and makes it possible to skip
IDAT chunks in the sequential reader (broken in earlier 1.6 versions).
There is a new test program, test-unknown.c, which is a work in progress
(not currently part of the test suite). Comments in the header files now
explain how the unknown handling works.
default. Also changed some warnings in the iCCP and sRGB handling
from to benign errors. Configuration now makes read benign
errors warnings and write benign errors to errors by default (thus
changing the behavior on read). The simplified API always forces
read benign errors to errors (regardless of the system default, unless
this is disabled in which case the simplified API can't be built.)
functions [rw]util.c. A new shared keyword check routine was also added
and the 'zbuf' is no longer allocated on progressive read. It is now
possible to call png_inflate() incrementally.
to reset the user limits to safe ones if PNG_SAFE_LIMITS is defined.
To enable, use CPPFLAGS=-DPNG_SAFE_LIMITS on the configure command
or put #define PNG_SAFE_LIMITS_SUPPORTED in pnglibconf.h.prebuilt.
(Reverted previous implementation of PNG_SECURE.)
It is too risky. Exactly how png_ptr->zbuf is used is under control of the
individual chunk implementation and there could easily be significant changes
within a major release.
wrong (high by one) 25% of the time. Dividing by 257 with rounding is
wrong in 128 out of 65536 cases. Getting the right answer all the time
without division is easy.
