[libcamera-devel] [PATCH v3 17/18] py: generate pixel formats list

[Kieran Bingham]

Quoting Laurent Pinchart (2022-05-18 14:54:39)
> Hi Tomi,
> 
> Thank you for the patch.
> 
> On Wed, May 18, 2022 at 04:13:28PM +0300, Tomi Valkeinen wrote:
> > Generate a list of pixel formats under "libcamera.formats".
> > 
> > I'm not super happy about this solution, as the user can change the
> > formats (libcamera.formats.XRGB8888 = None) and, for some reason,
> 
> I won't make it a blocker for this patch, but is there a way this could
> be fixed ?
> 

Are these types generated with this name 'libcamera.' or is that
inherited by being in the module?

I.e. would
 "import libcamera as cam"
make these cam.formats.XRGB8888 ?

> > pybind11-stubgen doesn't produce stubs for this.
> > 
> > However, other than the two issues above, it works, and I haven't
> > figured out a better way.
> > 
> > Signed-off-by: Tomi Valkeinen <tomi.valkeinen at ideasonboard.com>
> > ---
> >  src/py/libcamera/gen-py-formats.py           | 56 ++++++++++++++++++++
> >  src/py/libcamera/meson.build                 | 12 +++++
> >  src/py/libcamera/py_formats_generated.cpp.in | 21 ++++++++
> >  src/py/libcamera/py_main.cpp                 |  3 ++
> >  4 files changed, 92 insertions(+)
> >  create mode 100755 src/py/libcamera/gen-py-formats.py
> >  create mode 100644 src/py/libcamera/py_formats_generated.cpp.in
> > 
> > diff --git a/src/py/libcamera/gen-py-formats.py b/src/py/libcamera/gen-py-formats.py
> > new file mode 100755
> > index 00000000..72565a25
> > --- /dev/null
> > +++ b/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'formats.attr("{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))
> > diff --git a/src/py/libcamera/meson.build b/src/py/libcamera/meson.build
> > index a3388c63..0a7b65f3 100644
> > --- a/src/py/libcamera/meson.build
> > +++ b/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,
> > diff --git a/src/py/libcamera/py_formats_generated.cpp.in b/src/py/libcamera/py_formats_generated.cpp.in
> > new file mode 100644
> > index 00000000..1100c024
> > --- /dev/null
> > +++ b/src/py/libcamera/py_formats_generated.cpp.in
> > @@ -0,0 +1,21 @@
> > +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> > +/*
> > + * Copyright (C) 2022, Tomi Valkeinen <tomi.valkeinen at 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;
> > +
> > +void init_py_formats_generated(py::module& m)
> > +{
> > +auto formats = m.def_submodule("formats");
> > +
> > +${formats}
> 
> Could you indent this ? It's nicer to keep generated files readable.
> 
> Apart from that,
> 
> Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>


Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>

> 
> > +}
> > diff --git a/src/py/libcamera/py_main.cpp b/src/py/libcamera/py_main.cpp
> > index 1d941160..e7066841 100644
> > --- a/src/py/libcamera/py_main.cpp
> > +++ b/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);
> >  
> 
> -- 
> Regards,
> 
> Laurent Pinchart