* Add support to write mapping tables to the JPEG byte stream.
* Add API method to set the table ID for a component
* Add method to create JPEG-LS file with mapping tables only.
* Add support to read mapping tables
* Parse table-ids from the scan segment
* Extend API of charls_decoder_get_mapping_table_index to return -1 if index is not found
* Add support to read mapping table continuation segments
* Document new API methods
* Add sample image from appendix H.4.5 "Example of a palletised image" / Figure H.10 to unit test
* Update the get_mapping_table API to include size of the buffer
Don't derive quad from triplet, but make it a standalone type with just 4 members.
Note: additional dummy operators are needed for the color transforms. This is required for the current template design.
HP never defined the (non-standard JPEG-LS) color transformation for anything else then 3 components.
The upgrade to C++17 allows to get rid of the following macros:
CHARLS_NO_DISCARD : [[nodiscard]] can now always be used in C++ code
CHARLS_DEPRECATED: there are no deprecated types\methods anymore
CHARLS_CONSTEXPR_INLINE: inline constexpr is allowed in C++17
CHARLS_CONSTEXPR: Support for VS 2015 has been dropped, constexpr can always be used.
Backport C++20 countl_zero
1) countl_zero can be used in peek_0_bits and is 2X faster.
Note: peek_0_bits is not on a hot path, overall gain is limited.
2) Apply updates for clang-tidy v13 (ships with VS 2022 17.1 Preview 2)
3) Increase upper range of supported CMake to 3.22
The C++ attribute [[nodiscard]] requires C++17.
Using _Check_return_ or __attribute__((warn_unused_result)) ensures C++14 and C apps are covered.
__attribute__((warn_unused_result)) cannot be used in front of an enum.
Using CHARLS_CHECK_RETURN directly in front of the API functions ensure the best coverage.
Add also CHARLS_ATTRIBUTE_ACCESS((access()) annotations.
Note that only GCC 10 or newer is required for this annotation attribute.
Using the prefix CHARLS is a more clear identification that the macros belongs to the CharLS library. It also reduces the risk with conflicts of other 3rd party headers.
charls_jpegls_decoder_create and charls_jpegls_encoder_create may return null pointers. Add SAL annotations on those functions.
note: remove API docs for removed parameters
Both the MSVC and the gcc\clang C++ compiler provide additional attributes that can be used to assist the static analyzer build into these compilers to detect problems at compile time.
The problem is that these extension attributes are not cross compiler compatible, which requires additional macros to ensure that all supported compiler can compile the code.
The main focus of adding these attributes is on the external C API as in that area the most errors can be made.
Apply the modern way of documenting the used license, by referencing a SPDX Unique License Identifier in the source code files.
Note: From the legal point of view, this commit is only a change to the textual representation of the license information, but in no way any change to the actual license terms. With this commit applied, all files will still be licensed under the same terms they were before.
The current C API prevents adding new features and the introduction of an object oriented C++ interface. Every change results directly in a ABI break. To prevent this a new C API is introduced that is easier to extend and to maintain. On top of this API are 2 C++ classes: jpeg_encoder and jpeg_decoder to encode and decode JPEG-LS files.
This commit comes also with the following changes:
- Updated .clang-format
- Switch to Visual Studio 2019 for the CI build pipeline
- Support for reading and writing SPIFF header
- Incomplete support for JFIF header has been removed
- Extended unit test coverage
Since C++11, it is possible to return rich error information. Replace the custom way of returning error values and strings with the C++ standard way.
The only limitation is that the strings need to fixed and cannot use parameters. This should be no limitation in practice.
