py: Generate pixel formats list

Generate a list of pixel formats under 'libcamera.formats'.

The 'formats' is a "dummy" container class, the only purpose of which is
to contain the read-only pixel format properties.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

src/py/libcamera/gen-py-formats.py

@@ -0,0 +1,56 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# Generate Python format definitions from YAML
+
+import argparse
+import string
+import sys
+import yaml
+
+
+def generate(formats):
+    fmts = []
+
+    for format in formats:
+        name, format = format.popitem()
+        fmts.append(f'\t\t.def_readonly_static("{name}", &libcamera::formats::{name})')
+
+    return {'formats': '\n'.join(fmts)}
+
+
+def fill_template(template, data):
+    with open(template, encoding='utf-8') as f:
+        template = f.read()
+
+    template = string.Template(template)
+    return template.substitute(data)
+
+
+def main(argv):
+    parser = argparse.ArgumentParser()
+    parser.add_argument('-o', dest='output', metavar='file', type=str,
+                        help='Output file name. Defaults to standard output if not specified.')
+    parser.add_argument('input', type=str,
+                        help='Input file name.')
+    parser.add_argument('template', type=str,
+                        help='Template file name.')
+    args = parser.parse_args(argv[1:])
+
+    with open(args.input, encoding='utf-8') as f:
+        formats = yaml.safe_load(f)['formats']
+
+    data = generate(formats)
+    data = fill_template(args.template, data)
+
+    if args.output:
+        with open(args.output, 'w', encoding='utf-8') as f:
+            f.write(data)
+    else:
+        sys.stdout.write(data)
+
+    return 0
+
+
+if __name__ == '__main__':
+    sys.exit(main(sys.argv))

src/py/libcamera/meson.build

@@ -30,6 +30,18 @@ pycamera_sources += custom_target('py_gen_controls',
                                   output : ['py_control_enums_generated.cpp'],
                                   command : [gen_py_control_enums, '-o', '@OUTPUT@', '@INPUT@'])
 
+gen_py_formats_input_files = files([
+    '../../libcamera/formats.yaml',
+    'py_formats_generated.cpp.in',
+])
+
+gen_py_formats = files('gen-py-formats.py')
+
+pycamera_sources += custom_target('py_gen_formats',
+                                  input : gen_py_formats_input_files,
+                                  output : ['py_formats_generated.cpp'],
+                                  command : [gen_py_formats, '-o', '@OUTPUT@', '@INPUT@'])
+
 pycamera_deps = [
     libcamera_public,
     py3_dep,

src/py/libcamera/py_formats_generated.cpp.in

@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2022, Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
+ *
+ * Python bindings - Auto-generated formats
+ *
+ * This file is auto-generated. Do not edit.
+ */
+
+#include <libcamera/formats.h>
+
+#include <pybind11/smart_holder.h>
+
+namespace py = pybind11;
+
+class PyFormats
+{
+};
+
+void init_py_formats_generated(py::module& m)
+{
+	py::class_<PyFormats>(m, "formats")
+${formats}
+	;
+}

src/py/libcamera/py_main.cpp

@@ -132,6 +132,7 @@ static void handleRequestCompleted(Request *req)
 
 void init_py_enums(py::module &m);
 void init_py_control_enums_generated(py::module &m);
+void init_py_formats_generated(py::module &m);
 void init_py_geometry(py::module &m);
 
 PYBIND11_MODULE(_libcamera, m)
@@ -171,6 +172,8 @@ PYBIND11_MODULE(_libcamera, m)
 	auto pyColorSpaceRange = py::enum_<ColorSpace::Range>(pyColorSpace, "Range");
 	auto pyPixelFormat = py::class_<PixelFormat>(m, "PixelFormat");
 
+	init_py_formats_generated(m);
+
 	/* Global functions */
 	m.def("log_set_level", &logSetLevel);