[libcamera-devel] [RFC PATCH 00/12] Replace boost JSON parser with libyaml in Raspberry Pi IPA

[Laurent Pinchart]

Hello,

As mentioned in the subject, this patch series replaces the boost JSON
parser with the YamlParser implementation based on libyaml for the
Raspberry Pi IPA module.

The series starts with a few cleanups and extensions in YamlParser, with
patch 01/12 turning the enum Type into an enum class, patch 02/12
extending the size() function to support dictionaries in addition to
lists, and patch 03/12 moving the parser from using FILE to File for a
better RAII-style management of files. Patch 04/12 continues with a
small cleanup in the YamlParser unit tests.

Patch 05/12 introduces the first big change in the series: a new
iterator API for YamlObject. This allows iterating over the elements of
a list of dictionaly object. Unlike the boost property_tree
implementation that iterates over a pair of std::string key and ptree
value, the YamlObject iterators differ for lists and dictionaries. This
provides a more familiar API for lists, at the expense of requiring
adapter objects (see the asDict() and asList() functions). I'm
interested in feedback on this approach, hence the RFC. Patch 06/12
then extends the unit tests to cover the iterator API, and patch 07/12
uses the API in the Android camera HAL. Patch 08/12 completes that part
of the series by removing the then unused memberNames() function.

The series continue with two extensions to the YamlParser. In patch
09/12 the get() function receives a fix to properly check the value
range for 32-bit integers, and in patch 10/12 new specializations of
the function are added for 16-bit integers, needed by the Raspberry Pi
IPA.

The last part of the series converts the Raspberry Pi IPA from boost to
YamlParser. Small changes are needed in patch 11/12 to convert tabs to
spaces in the tuning JSON files, as they confuse the YAML parser. Patch
12/12 then converts the IPA module, and drops the dependency on boost.

When compiled in release mode with clang-13, the Raspberry Pi IPA module
.text section shrank from 1317086 to 963614 bytes.

I haven't been able to test the series on a Raspberry Pi yet (second
reason for the RFC) as I don't have access to my board at the moment.

Laurent Pinchart (12):
  libcamera: yaml_object: Turn Type into an enum class
  libcamera: yaml_parser: Extend YamlObject::size() to dictionaries
  libcamera: yaml_parser: Switch from FILE to File
  test: yaml-parser: Use write() instead of fwrite()
  libcamera: yaml_parser: Add iterator API
  test: yaml_parser: Extend tests to cover the iterator API
  android: Use the YamlObject iterator API
  libcamera: yaml_parser: Remove memberNames() function
  libcamera: yaml_parser: Fix range checks for 32-bit integers
  libcamera: yaml_parser: Add get() specializations for 16-bit integers
  ipa: raspberrypi: Replace tabs with spaces in tuning data files
  ipa: raspberrypi: Use YamlParser to replace dependency on boost

 README.rst                                    |   6 -
 include/libcamera/internal/yaml_parser.h      | 133 +++++++++-
 src/android/camera_hal_config.cpp             |  22 +-
 src/ipa/raspberrypi/controller/algorithm.cpp  |   2 +-
 src/ipa/raspberrypi/controller/algorithm.hpp  |   6 +-
 src/ipa/raspberrypi/controller/controller.cpp |  27 +-
 src/ipa/raspberrypi/controller/pwl.cpp        |  12 +-
 src/ipa/raspberrypi/controller/pwl.hpp        |   5 +-
 src/ipa/raspberrypi/controller/rpi/agc.cpp    |  94 +++----
 src/ipa/raspberrypi/controller/rpi/agc.hpp    |  10 +-
 src/ipa/raspberrypi/controller/rpi/alsc.cpp   |  94 ++++---
 src/ipa/raspberrypi/controller/rpi/alsc.hpp   |   2 +-
 src/ipa/raspberrypi/controller/rpi/awb.cpp    |  89 +++----
 src/ipa/raspberrypi/controller/rpi/awb.hpp    |   8 +-
 .../controller/rpi/black_level.cpp            |  12 +-
 .../controller/rpi/black_level.hpp            |   2 +-
 src/ipa/raspberrypi/controller/rpi/ccm.cpp    |  28 +--
 src/ipa/raspberrypi/controller/rpi/ccm.hpp    |   4 +-
 .../raspberrypi/controller/rpi/contrast.cpp   |  18 +-
 .../raspberrypi/controller/rpi/contrast.hpp   |   2 +-
 src/ipa/raspberrypi/controller/rpi/dpc.cpp    |   4 +-
 src/ipa/raspberrypi/controller/rpi/dpc.hpp    |   2 +-
 src/ipa/raspberrypi/controller/rpi/geq.cpp    |  10 +-
 src/ipa/raspberrypi/controller/rpi/geq.hpp    |   2 +-
 src/ipa/raspberrypi/controller/rpi/lux.cpp    |  12 +-
 src/ipa/raspberrypi/controller/rpi/lux.hpp    |   2 +-
 src/ipa/raspberrypi/controller/rpi/noise.cpp  |   6 +-
 src/ipa/raspberrypi/controller/rpi/noise.hpp  |   2 +-
 src/ipa/raspberrypi/controller/rpi/sdn.cpp    |   6 +-
 src/ipa/raspberrypi/controller/rpi/sdn.hpp    |   2 +-
 .../raspberrypi/controller/rpi/sharpen.cpp    |   8 +-
 .../raspberrypi/controller/rpi/sharpen.hpp    |   2 +-
 src/ipa/raspberrypi/data/imx219.json          |   8 +-
 src/ipa/raspberrypi/data/imx219_noir.json     |  10 +-
 src/ipa/raspberrypi/data/imx290.json          |  18 +-
 src/ipa/raspberrypi/data/imx477.json          |   8 +-
 src/ipa/raspberrypi/data/imx477_noir.json     |  10 +-
 src/ipa/raspberrypi/data/ov5647.json          |  10 +-
 src/ipa/raspberrypi/data/ov5647_noir.json     |  12 +-
 src/ipa/raspberrypi/data/se327m12.json        |   6 +-
 src/ipa/raspberrypi/meson.build               |   1 -
 src/ipa/raspberrypi/raspberrypi.cpp           |   1 +
 src/libcamera/yaml_parser.cpp                 | 232 +++++++++++++-----
 test/yaml-parser.cpp                          | 109 +++++---
 44 files changed, 659 insertions(+), 400 deletions(-)


base-commit: 153b468930a9df22debb28889312f8a5c511ee04
-- 
Regards,

Laurent Pinchart