[libcamera-devel] [PATCH v7 04/13] Add Python bindings

Laurent Pinchart laurent.pinchart at ideasonboard.com
Thu May 5 19:32:11 CEST 2022


On Thu, May 05, 2022 at 02:51:34PM +0100, Kieran Bingham wrote:
> Quoting Tomi Valkeinen (2022-05-05 11:40:55)
> > Add libcamera Python bindings. pybind11 is used to generate the C++ <->
> > Python layer.
> > 
> > We use pybind11 'smart_holder' version to avoid issues with private
> > destructors and shared_ptr. There is also an alternative solution here:
> > 
> > https://github.com/pybind/pybind11/pull/2067
> > 
> > Only a subset of libcamera classes are exposed. Implementing and testing
> > the wrapper classes is challenging, and as such only classes that I have
> > needed have been added so far.
> > 
> > Signed-off-by: Tomi Valkeinen <tomi.valkeinen at ideasonboard.com>
> > ---
> >  meson.build                                   |   1 +
> >  meson_options.txt                             |   5 +
> >  src/meson.build                               |   1 +
> >  src/py/libcamera/__init__.py                  |  12 +
> >  src/py/libcamera/meson.build                  |  44 ++
> >  src/py/libcamera/pyenums.cpp                  |  53 ++
> >  src/py/libcamera/pymain.cpp                   | 452 ++++++++++++++++++
> >  src/py/meson.build                            |   1 +
> >  subprojects/.gitignore                        |   3 +-
> >  subprojects/packagefiles/pybind11/meson.build |   8 +
> >  subprojects/pybind11.wrap                     |   8 +
> >  11 files changed, 587 insertions(+), 1 deletion(-)
> >  create mode 100644 src/py/libcamera/__init__.py
> >  create mode 100644 src/py/libcamera/meson.build
> >  create mode 100644 src/py/libcamera/pyenums.cpp
> >  create mode 100644 src/py/libcamera/pymain.cpp
> >  create mode 100644 src/py/meson.build
> >  create mode 100644 subprojects/packagefiles/pybind11/meson.build
> >  create mode 100644 subprojects/pybind11.wrap
> > 
> > diff --git a/meson.build b/meson.build
> > index 0124e7d3..60a911e0 100644
> > --- a/meson.build
> > +++ b/meson.build
> > @@ -177,6 +177,7 @@ summary({
> >              'Tracing support': tracing_enabled,
> >              'Android support': android_enabled,
> >              'GStreamer support': gst_enabled,
> > +            'Python bindings': pycamera_enabled,
> >              'V4L2 emulation support': v4l2_enabled,
> >              'cam application': cam_enabled,
> >              'qcam application': qcam_enabled,
> > diff --git a/meson_options.txt b/meson_options.txt
> > index 2c80ad8b..ca00c78e 100644
> > --- a/meson_options.txt
> > +++ b/meson_options.txt
> > @@ -58,3 +58,8 @@ option('v4l2',
> >          type : 'boolean',
> >          value : false,
> >          description : 'Compile the V4L2 compatibility layer')
> > +
> > +option('pycamera',
> > +        type : 'feature',
> > +        value : 'auto',
> > +        description : 'Enable libcamera Python bindings (experimental)')
> > diff --git a/src/meson.build b/src/meson.build
> > index e0ea9c35..34663a6f 100644
> > --- a/src/meson.build
> > +++ b/src/meson.build
> > @@ -37,4 +37,5 @@ subdir('cam')
> >  subdir('qcam')
> >  
> >  subdir('gstreamer')
> > +subdir('py')
> >  subdir('v4l2')
> > diff --git a/src/py/libcamera/__init__.py b/src/py/libcamera/__init__.py
> > new file mode 100644
> > index 00000000..cd7512a2
> > --- /dev/null
> > +++ b/src/py/libcamera/__init__.py
> > @@ -0,0 +1,12 @@
> > +# SPDX-License-Identifier: LGPL-2.1-or-later
> > +# Copyright (C) 2021, Tomi Valkeinen <tomi.valkeinen at ideasonboard.com>

You may want to bump the copyright year :-) Same below.

> > +
> > +from ._libcamera import *
> > +import mmap
> > +
> > +
> > +def __FrameBuffer__mmap(self, plane):

Let's record that more work is needed:

    # \todo Support multi-planar formats

> > +    return mmap.mmap(self.fd(plane), self.length(plane), mmap.MAP_SHARED, mmap.PROT_READ)
> > +
> > +
> > +FrameBuffer.mmap = __FrameBuffer__mmap
> > diff --git a/src/py/libcamera/meson.build b/src/py/libcamera/meson.build
> > new file mode 100644
> > index 00000000..e1f5cf21
> > --- /dev/null
> > +++ b/src/py/libcamera/meson.build
> > @@ -0,0 +1,44 @@
> > +# SPDX-License-Identifier: CC0-1.0
> > +
> > +py3_dep = dependency('python3', required : get_option('pycamera'))
> > +
> > +if not py3_dep.found()
> > +    pycamera_enabled = false
> > +    subdir_done()
> > +endif
> > +
> > +pycamera_enabled = true
> > +
> > +pybind11_proj = subproject('pybind11')
> > +pybind11_dep = pybind11_proj.get_variable('pybind11_dep')
> > +
> > +pycamera_sources = files([
> > +    'pymain.cpp',
> > +    'pyenums.cpp',

Alphabetical order please.

> > +])
> > +
> > +pycamera_deps = [
> > +    libcamera_public,
> > +    py3_dep,
> > +    pybind11_dep,
> > +]
> > +
> > +pycamera_args = ['-fvisibility=hidden']
> > +pycamera_args += ['-Wno-shadow']
> > +pycamera_args += ['-DPYBIND11_USE_SMART_HOLDER_AS_DEFAULT']

You could write this as

pycamera_args = [
    '-fvisibility=hidden',
    '-Wno-shadow',
    '-DPYBIND11_USE_SMART_HOLDER_AS_DEFAULT',
]

> > +
> > +destdir = get_option('libdir') + '/python' + py3_dep.version() + '/site-packages/libcamera'

destdir = get_option('libdir') / ('python' + py3_dep.version()) / 'site-packages' / 'libcamera'

> > +
> > +pycamera = shared_module('_libcamera',
> > +                         pycamera_sources,
> > +                         install : true,
> > +                         install_dir : destdir,
> > +                         name_prefix : '',
> > +                         dependencies : pycamera_deps,
> > +                         cpp_args : pycamera_args)
> > +
> > +run_command('ln', '-fsT', '../../../../src/py/libcamera/__init__.py',
> > +            meson.current_build_dir() / '__init__.py',
> > +            check: true)
> > +
> > +install_data(['__init__.py'], install_dir : destdir)
> > diff --git a/src/py/libcamera/pyenums.cpp b/src/py/libcamera/pyenums.cpp
> > new file mode 100644
> > index 00000000..39886656
> > --- /dev/null
> > +++ b/src/py/libcamera/pyenums.cpp
> > @@ -0,0 +1,53 @@
> > +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> > +/*
> > + * Copyright (C) 2021, Tomi Valkeinen <tomi.valkeinen at ideasonboard.com>
> > + *
> > + * Python bindings

This could be a bit more descriptive:

 * Python bindings - Enumerations

> > + */
> > +
> > +#include <libcamera/libcamera.h>
> > +
> > +#include <pybind11/smart_holder.h>
> > +
> > +namespace py = pybind11;
> > +
> > +using namespace libcamera;
> > +
> > +void init_pyenums(py::module &m)
> > +{
> > +       py::enum_<CameraConfiguration::Status>(m, "ConfigurationStatus")
> > +               .value("Valid", CameraConfiguration::Valid)
> > +               .value("Adjusted", CameraConfiguration::Adjusted)
> > +               .value("Invalid", CameraConfiguration::Invalid);

It would be nice if C++ had some introspection capabilities that would
allow this to be done automatically :-)

> > +
> > +       py::enum_<StreamRole>(m, "StreamRole")
> > +               .value("StillCapture", StreamRole::StillCapture)
> > +               .value("Raw", StreamRole::Raw)
> > +               .value("VideoRecording", StreamRole::VideoRecording)
> > +               .value("Viewfinder", StreamRole::Viewfinder);
> > +
> > +       py::enum_<Request::Status>(m, "RequestStatus")
> > +               .value("Pending", Request::RequestPending)

I wonder if the C++ enum should turn into an enum class, and the
enumerators renamed to drop the Request prefix.

> > +               .value("Complete", Request::RequestComplete)
> > +               .value("Cancelled", Request::RequestCancelled);

Nothing that needs to be changed now, by what is more pythonic between

    Request.Status.Pending

and

    RequestStatus.Pending

?

> > +
> > +       py::enum_<FrameMetadata::Status>(m, "FrameMetadataStatus")
> > +               .value("Success", FrameMetadata::FrameSuccess)

Same here, an enum class may make sense.

> > +               .value("Error", FrameMetadata::FrameError)
> > +               .value("Cancelled", FrameMetadata::FrameCancelled);
> > +
> > +       py::enum_<Request::ReuseFlag>(m, "ReuseFlag")
> > +               .value("Default", Request::ReuseFlag::Default)
> > +               .value("ReuseBuffers", Request::ReuseFlag::ReuseBuffers);
> > +
> > +       py::enum_<ControlType>(m, "ControlType")
> > +               .value("None", ControlType::ControlTypeNone)

Ditto.

> > +               .value("Bool", ControlType::ControlTypeBool)
> > +               .value("Byte", ControlType::ControlTypeByte)
> > +               .value("Integer32", ControlType::ControlTypeInteger32)
> > +               .value("Integer64", ControlType::ControlTypeInteger64)
> > +               .value("Float", ControlType::ControlTypeFloat)
> > +               .value("String", ControlType::ControlTypeString)
> > +               .value("Rectangle", ControlType::ControlTypeRectangle)
> > +               .value("Size", ControlType::ControlTypeSize);
> > +}
> > diff --git a/src/py/libcamera/pymain.cpp b/src/py/libcamera/pymain.cpp
> > new file mode 100644
> > index 00000000..54674caf
> > --- /dev/null
> > +++ b/src/py/libcamera/pymain.cpp
> > @@ -0,0 +1,452 @@
> > +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> > +/*
> > + * Copyright (C) 2021, Tomi Valkeinen <tomi.valkeinen at ideasonboard.com>
> > + *
> > + * Python bindings
> > + */
> > +
> > +/*
> > + * To generate pylibcamera stubs:
> > + * PYTHONPATH=build/src/py pybind11-stubgen --no-setup-py -o build/src/py libcamera

What is this for ?

> > + */
> > +
> > +#include <chrono>
> > +#include <fcntl.h>
> > +#include <mutex>
> > +#include <sys/eventfd.h>
> > +#include <sys/mman.h>
> > +#include <thread>
> > +#include <unistd.h>
> > +
> > +#include <libcamera/libcamera.h>
> > +
> > +#include <pybind11/functional.h>
> > +#include <pybind11/smart_holder.h>
> > +#include <pybind11/stl.h>
> > +#include <pybind11/stl_bind.h>
> > +
> > +namespace py = pybind11;
> > +
> > +using namespace std;

You're using the std:: namespace qualifier explicitly in several
location below. Could we do that everywhere and drop the using namespace
directive ?

> > +using namespace libcamera;
> > +
> > +template<typename T>
> > +static py::object ValueOrTuple(const ControlValue &cv)

Could you rename this to valueOrTuple() to follow the libcamera coding
style ? Or would that look awkward from a python bindings coding style
point of view ?

Same for ControlValueToPy and PyToControlValue.

> > +{
> > +       if (cv.isArray()) {
> > +               const T *v = reinterpret_cast<const T *>(cv.data().data());
> > +               auto t = py::tuple(cv.numElements());
> > +
> > +               for (size_t i = 0; i < cv.numElements(); ++i)
> > +                       t[i] = v[i];
> > +
> > +               return t;
> > +       }
> > +
> > +       return py::cast(cv.get<T>());
> > +}
> > +
> > +static py::object ControlValueToPy(const ControlValue &cv)
> > +{
> > +       switch (cv.type()) {
> > +       case ControlTypeBool:
> > +               return ValueOrTuple<bool>(cv);
> > +       case ControlTypeByte:
> > +               return ValueOrTuple<uint8_t>(cv);
> > +       case ControlTypeInteger32:
> > +               return ValueOrTuple<int32_t>(cv);
> > +       case ControlTypeInteger64:
> > +               return ValueOrTuple<int64_t>(cv);
> > +       case ControlTypeFloat:
> > +               return ValueOrTuple<float>(cv);
> > +       case ControlTypeString:
> > +               return py::cast(cv.get<string>());
> > +       case ControlTypeRectangle: {

	/* \todo Add geometry classes to the Python bindings */

> > +               const Rectangle *v = reinterpret_cast<const Rectangle *>(cv.data().data());
> > +               return py::make_tuple(v->x, v->y, v->width, v->height);
> > +       }
> > +       case ControlTypeSize: {
> > +               const Size *v = reinterpret_cast<const Size *>(cv.data().data());
> > +               return py::make_tuple(v->width, v->height);
> > +       }
> > +       case ControlTypeNone:
> > +       default:
> > +               throw runtime_error("Unsupported ControlValue type");
> > +       }
> > +}
> > +
> > +static ControlValue PyToControlValue(const py::object &ob, ControlType type)
> > +{
> > +       switch (type) {
> > +       case ControlTypeBool:
> > +               return ControlValue(ob.cast<bool>());
> > +       case ControlTypeByte:
> > +               return ControlValue(ob.cast<uint8_t>());
> > +       case ControlTypeInteger32:
> > +               return ControlValue(ob.cast<int32_t>());
> > +       case ControlTypeInteger64:
> > +               return ControlValue(ob.cast<int64_t>());
> > +       case ControlTypeFloat:
> > +               return ControlValue(ob.cast<float>());
> > +       case ControlTypeString:
> > +               return ControlValue(ob.cast<string>());
> > +       case ControlTypeRectangle:
> > +       case ControlTypeSize:

A todo comment would be nice here too.

> > +       case ControlTypeNone:
> > +       default:
> > +               throw runtime_error("Control type not implemented");
> > +       }
> > +}
> > +
> > +static weak_ptr<CameraManager> g_camera_manager;

Coding style here too, gCameraManager, or would that look too awkward ?
Same below.

> > +static int g_eventfd;
> > +static mutex g_reqlist_mutex;
> > +static vector<Request *> g_reqlist;
> > +
> > +static void handleRequestCompleted(Request *req)
> > +{
> > +       {
> > +               lock_guard guard(g_reqlist_mutex);
> > +               g_reqlist.push_back(req);
> > +       }
> > +
> > +       uint64_t v = 1;
> > +       write(g_eventfd, &v, 8);
> > +}
> > +
> > +void init_pyenums(py::module &m);
> > +
> > +PYBIND11_MODULE(_libcamera, m)
> > +{
> > +       init_pyenums(m);
> > +
> > +       /* Forward declarations */
> > +
> > +       /*
> > +        * We need to declare all the classes here so that Python docstrings
> > +        * can be generated correctly.
> > +        * https://pybind11.readthedocs.io/en/latest/advanced/misc.html#avoiding-c-types-in-docstrings
> > +        */
> > +
> > +       auto pyCameraManager = py::class_<CameraManager>(m, "CameraManager");
> > +       auto pyCamera = py::class_<Camera>(m, "Camera");
> > +       auto pyCameraConfiguration = py::class_<CameraConfiguration>(m, "CameraConfiguration");
> > +       auto pyStreamConfiguration = py::class_<StreamConfiguration>(m, "StreamConfiguration");
> > +       auto pyStreamFormats = py::class_<StreamFormats>(m, "StreamFormats");
> > +       auto pyFrameBufferAllocator = py::class_<FrameBufferAllocator>(m, "FrameBufferAllocator");
> > +       auto pyFrameBuffer = py::class_<FrameBuffer>(m, "FrameBuffer");
> > +       auto pyStream = py::class_<Stream>(m, "Stream");
> > +       auto pyControlId = py::class_<ControlId>(m, "ControlId");
> > +       auto pyRequest = py::class_<Request>(m, "Request");
> > +       auto pyFrameMetadata = py::class_<FrameMetadata>(m, "FrameMetadata");

Could you please sort these alphabetically ?

> > +
> > +       /* Global functions */
> > +       m.def("logSetLevel", &logSetLevel);
> > +
> > +       /* Classes */
> > +       pyCameraManager
> > +               .def_static("singleton", []() {
> > +                       shared_ptr<CameraManager> cm = g_camera_manager.lock();
> > +                       if (cm)
> > +                               return cm;
> > +
> > +                       int fd = eventfd(0, 0);
> > +                       if (fd == -1)
> > +                               throw std::system_error(errno, std::generic_category(), "Failed to create eventfd");

Some long lines like this one can be wrapped:

				throw std::system_error(errno, std::generic_category(),
							"Failed to create eventfd");
> > +
> > +                       cm = shared_ptr<CameraManager>(new CameraManager, [](auto p) {
> > +                               close(g_eventfd);
> > +                               g_eventfd = -1;
> > +                               delete p;
> > +                       });
> > +
> > +                       g_eventfd = fd;
> > +                       g_camera_manager = cm;
> > +
> > +                       int ret = cm->start();
> > +                       if (ret)
> > +                               throw std::system_error(-ret, std::generic_category(), "Failed to start CameraManager");
> > +
> > +                       return cm;
> > +               })
> > +
> > +               .def_property_readonly("version", &CameraManager::version)
> > +
> > +               .def_property_readonly("efd", [](CameraManager &) {
> > +                       return g_eventfd;
> > +               })
> > +
> > +               .def("getReadyRequests", [](CameraManager &) {

As we don't usually prefix getters with "get", maybe just
"readyRequests" ?

> > +                       vector<Request *> v;
> > +
> > +                       {
> > +                               lock_guard guard(g_reqlist_mutex);
> > +                               swap(v, g_reqlist);
> > +                       }
> > +
> > +                       vector<py::object> ret;
> > +
> > +                       for (Request *req : v) {
> > +                               py::object o = py::cast(req);
> > +                               /* decrease the ref increased in Camera::queueRequest() */

s/decrease/Decrease/

> > +                               o.dec_ref();
> > +                               ret.push_back(o);
> > +                       }
> > +
> > +                       return ret;
> > +               })
> > +
> > +               .def("get", py::overload_cast<const string &>(&CameraManager::get), py::keep_alive<0, 1>())
> > +
> > +               .def("find", [](CameraManager &self, string str) {
> > +                       std::transform(str.begin(), str.end(), str.begin(), ::tolower);
> > +
> > +                       for (auto c : self.cameras()) {
> > +                               string id = c->id();
> > +
> > +                               std::transform(id.begin(), id.end(), id.begin(), ::tolower);

Do we really want to ignore the case in the comparison here ?

> > +
> > +                               if (id.find(str) != string::npos)

Actually, does this function really belong in the python bindings ? It
seems to be used in unit tests only, where you could iterate over the
cameras exposed by the cameras property instead.

> > +                                       return c;
> > +                       }
> > +
> > +                       return shared_ptr<Camera>();
> > +               }, py::keep_alive<0, 1>())
> > +
> > +               /* Create a list of Cameras, where each camera has a keep-alive to CameraManager */
> > +               .def_property_readonly("cameras", [](CameraManager &self) {
> > +                       py::list l;
> > +
> > +                       for (auto &c : self.cameras()) {
> > +                               py::object py_cm = py::cast(self);
> > +                               py::object py_cam = py::cast(c);
> > +                               py::detail::keep_alive_impl(py_cam, py_cm);
> > +                               l.append(py_cam);
> > +                       }
> > +
> > +                       return l;
> > +               });
> > +
> > +       pyCamera
> > +               .def_property_readonly("id", &Camera::id)
> > +               .def("acquire", &Camera::acquire)
> > +               .def("release", &Camera::release)
> > +               .def("start", [](Camera &self) {
> > +                       self.requestCompleted.connect(handleRequestCompleted);
> 
> What happens if someone calls start() multiple times? Is that going to
> mean the signal / slot will be connected multiple times?
> 
> That could be problematic ... as I think it means it could then call the
> request completed handler multiple times - but it may also already be
> trapped by the recent work we did around there.
> 
> So for now I think this is fine - but may be something to test or
> consider later.

Indeed. A \todo comment would be nice.

> > +
> > +                       int ret = self.start();
> > +                       if (ret)
> > +                               self.requestCompleted.disconnect(handleRequestCompleted);
> > +
> > +                       return ret;

			int ret = self.start();
			if (ret) {
				self.requestCompleted.disconnect(handleRequestCompleted);
				return ret;
			}

			return 0;

> > +               })
> > +
> > +               .def("stop", [](Camera &self) {
> > +                       int ret = self.stop();
> > +                       if (!ret)
> > +                               self.requestCompleted.disconnect(handleRequestCompleted);
> > +
> > +                       return ret;

			int ret = self.stop();
			if (ret)
				return ret;

			self.requestCompleted.disconnect(handleRequestCompleted);
			return 0;

> > +               })
> > +
> > +               .def("__repr__", [](Camera &self) {
> > +                       return "<libcamera.Camera '" + self.id() + "'>";
> > +               })
> > +
> > +               /* Keep the camera alive, as StreamConfiguration contains a Stream* */
> > +               .def("generateConfiguration", &Camera::generateConfiguration, py::keep_alive<0, 1>())
> > +               .def("configure", &Camera::configure)
> > +
> > +               .def("createRequest", &Camera::createRequest, py::arg("cookie") = 0)
> > +
> > +               .def("queueRequest", [](Camera &self, Request *req) {
> > +                       py::object py_req = py::cast(req);
> > +

			/*
			 * Increase the reference count, will be dropped in
			 * getReadyRequests().
			 */

I wonder what happens if nobody calls getReadyRequests() though, for
instance for the last requesuts when stopping the camera. If there's an
issue there, please add a \todo comment somewhere.

> > +                       py_req.inc_ref();
> > +
> > +                       int ret = self.queueRequest(req);
> > +                       if (ret)
> > +                               py_req.dec_ref();
> > +
> > +                       return ret;
> > +               })
> > +
> > +               .def_property_readonly("streams", [](Camera &self) {
> > +                       py::set set;
> > +                       for (auto &s : self.streams()) {
> > +                               py::object py_self = py::cast(self);
> > +                               py::object py_s = py::cast(s);
> > +                               py::detail::keep_alive_impl(py_s, py_self);
> > +                               set.add(py_s);
> > +                       }
> > +                       return set;
> > +               })
> > +
> > +               .def("find_control", [](Camera &self, const string &name) {

"findControl"

> > +                       const auto &controls = self.controls();
> > +
> > +                       auto it = find_if(controls.begin(), controls.end(),
> > +                                         [&name](const auto &kvp) { return kvp.first->name() == name; });
> > +
> > +                       if (it == controls.end())
> > +                               throw runtime_error("Control not found");
> > +
> > +                       return it->first;
> > +               }, py::return_value_policy::reference_internal)
> > +
> > +               .def_property_readonly("controls", [](Camera &self) {
> > +                       py::dict ret;
> > +
> > +                       for (const auto &[id, ci] : self.controls()) {

				/* \todo Add bindings for the ControlInfo class */

> > +                               ret[id->name().c_str()] = make_tuple<py::object>(ControlValueToPy(ci.min()),
> > +                                                                                ControlValueToPy(ci.max()),
> > +                                                                                ControlValueToPy(ci.def()));
> > +                       }
> > +
> > +                       return ret;
> > +               })
> > +
> > +               .def_property_readonly("properties", [](Camera &self) {
> > +                       py::dict ret;
> > +
> > +                       for (const auto &[key, cv] : self.properties()) {
> > +                               const ControlId *id = properties::properties.at(key);
> > +                               py::object ob = ControlValueToPy(cv);
> > +
> > +                               ret[id->name().c_str()] = ob;
> > +                       }
> > +
> > +                       return ret;
> > +               });
> > +
> > +       pyCameraConfiguration
> > +               .def("__iter__", [](CameraConfiguration &self) {
> > +                       return py::make_iterator<py::return_value_policy::reference_internal>(self);
> > +               }, py::keep_alive<0, 1>())
> > +               .def("__len__", [](CameraConfiguration &self) {
> > +                       return self.size();
> > +               })
> > +               .def("validate", &CameraConfiguration::validate)
> > +               .def("at", py::overload_cast<unsigned int>(&CameraConfiguration::at), py::return_value_policy::reference_internal)

Line wrap.

> > +               .def_property_readonly("size", &CameraConfiguration::size)
> > +               .def_property_readonly("empty", &CameraConfiguration::empty);
> > +
> > +       pyStreamConfiguration
> > +               .def("toString", &StreamConfiguration::toString)
> > +               .def_property_readonly("stream", &StreamConfiguration::stream, py::return_value_policy::reference_internal)
> > +               .def_property(
> > +                       "size",
> > +                       [](StreamConfiguration &self) { return make_tuple(self.size.width, self.size.height); },
> > +                       [](StreamConfiguration &self, tuple<uint32_t, uint32_t> size) { self.size.width = get<0>(size); self.size.height = get<1>(size); })

That's a very long line too.

			[](StreamConfiguration &self) {
				return make_tuple(self.size.width, self.size.height);
			},
			[](StreamConfiguration &self, tuple<uint32_t, uint32_t> size) {
				self.size.width = get<0>(size);
				self.size.height = get<1>(size);
			})

Same where applicable.

> > +               .def_property(
> > +                       "pixelFormat",
> > +                       [](StreamConfiguration &self) { return self.pixelFormat.toString(); },
> > +                       [](StreamConfiguration &self, string fmt) { self.pixelFormat = PixelFormat::fromString(fmt); })
> > +               .def_readwrite("stride", &StreamConfiguration::stride)
> > +               .def_readwrite("frameSize", &StreamConfiguration::frameSize)
> > +               .def_readwrite("bufferCount", &StreamConfiguration::bufferCount)
> > +               .def_property_readonly("formats", &StreamConfiguration::formats, py::return_value_policy::reference_internal);
> > +
> > +       pyStreamFormats
> > +               .def_property_readonly("pixelFormats", [](StreamFormats &self) {
> > +                       vector<string> fmts;
> > +                       for (auto &fmt : self.pixelformats())
> > +                               fmts.push_back(fmt.toString());
> > +                       return fmts;
> > +               })
> > +               .def("sizes", [](StreamFormats &self, const string &pixelFormat) {
> > +                       auto fmt = PixelFormat::fromString(pixelFormat);
> > +                       vector<tuple<uint32_t, uint32_t>> fmts;
> > +                       for (const auto &s : self.sizes(fmt))
> > +                               fmts.push_back(make_tuple(s.width, s.height));
> > +                       return fmts;
> > +               })
> > +               .def("range", [](StreamFormats &self, const string &pixelFormat) {
> > +                       auto fmt = PixelFormat::fromString(pixelFormat);
> > +                       const auto &range = self.range(fmt);
> > +                       return make_tuple(make_tuple(range.hStep, range.vStep),
> > +                                         make_tuple(range.min.width, range.min.height),
> > +                                         make_tuple(range.max.width, range.max.height));
> > +               });
> > +
> > +       pyFrameBufferAllocator
> > +               .def(py::init<shared_ptr<Camera>>(), py::keep_alive<1, 2>())
> > +               .def("allocate", &FrameBufferAllocator::allocate)
> > +               .def_property_readonly("allocated", &FrameBufferAllocator::allocated)
> > +               /* Create a list of FrameBuffers, where each FrameBuffer has a keep-alive to FrameBufferAllocator */
> > +               .def("buffers", [](FrameBufferAllocator &self, Stream *stream) {
> > +                       py::object py_self = py::cast(self);
> > +                       py::list l;
> > +                       for (auto &ub : self.buffers(stream)) {
> > +                               py::object py_buf = py::cast(ub.get(), py::return_value_policy::reference_internal, py_self);
> > +                               l.append(py_buf);
> > +                       }
> > +                       return l;
> > +               });
> > +
> > +       pyFrameBuffer
> > +               /* TODO: implement FrameBuffer::Plane properly */

s/TODO: implement/\\todo Implement/

> > +               .def(py::init([](vector<tuple<int, unsigned int>> planes, unsigned int cookie) {
> > +                       vector<FrameBuffer::Plane> v;
> > +                       for (const auto &t : planes)
> > +                               v.push_back({ SharedFD(get<0>(t)), FrameBuffer::Plane::kInvalidOffset, get<1>(t) });
> > +                       return new FrameBuffer(v, cookie);
> > +               }))
> > +               .def_property_readonly("metadata", &FrameBuffer::metadata, py::return_value_policy::reference_internal)
> > +               .def("length", [](FrameBuffer &self, uint32_t idx) {
> > +                       const FrameBuffer::Plane &plane = self.planes()[idx];
> > +                       return plane.length;
> > +               })
> > +               .def("fd", [](FrameBuffer &self, uint32_t idx) {
> > +                       const FrameBuffer::Plane &plane = self.planes()[idx];
> > +                       return plane.fd.get();
> > +               })
> > +               .def_property("cookie", &FrameBuffer::cookie, &FrameBuffer::setCookie);
> > +
> > +       pyStream
> > +               .def_property_readonly("configuration", &Stream::configuration);
> > +
> > +       pyControlId
> > +               .def_property_readonly("id", &ControlId::id)
> > +               .def_property_readonly("name", &ControlId::name)
> > +               .def_property_readonly("type", &ControlId::type);
> > +
> > +       pyRequest
> > +               /* Fence is not supported, so we cannot expose addBuffer() directly */
> > +               .def("addBuffer", [](Request &self, const Stream *stream, FrameBuffer *buffer) {
> > +                       return self.addBuffer(stream, buffer);
> > +               }, py::keep_alive<1, 3>()) /* Request keeps Framebuffer alive */
> > +               .def_property_readonly("status", &Request::status)
> > +               .def_property_readonly("buffers", &Request::buffers)
> > +               .def_property_readonly("cookie", &Request::cookie)
> > +               .def_property_readonly("hasPendingBuffers", &Request::hasPendingBuffers)
> > +               .def("set_control", [](Request &self, ControlId &id, py::object value) {
> > +                       self.controls().set(id.id(), PyToControlValue(value, id.type()));
> > +               })
> > +               .def_property_readonly("metadata", [](Request &self) {
> > +                       py::dict ret;
> > +
> > +                       for (const auto &[key, cv] : self.metadata()) {
> > +                               const ControlId *id = controls::controls.at(key);
> > +                               py::object ob = ControlValueToPy(cv);
> > +
> > +                               ret[id->name().c_str()] = ob;
> > +                       }
> > +
> > +                       return ret;
> > +               })
> > +               /* As we add a keep_alive to the fb in addBuffers(), we can only allow reuse with ReuseBuffers. */

That will be an annoying limitation. Can you add a todo comment to fix
it (and line wrap this comment) ?

> > +               .def("reuse", [](Request &self) { self.reuse(Request::ReuseFlag::ReuseBuffers); });
> > +
> > +       pyFrameMetadata
> > +               .def_readonly("status", &FrameMetadata::status)
> > +               .def_readonly("sequence", &FrameMetadata::sequence)
> > +               .def_readonly("timestamp", &FrameMetadata::timestamp)
> > +               /* temporary helper, to be removed */

		/* \todo Temporary helper, to be removed */

> > +               .def_property_readonly("bytesused", [](FrameMetadata &self) {
> > +                       vector<unsigned int> v;
> > +                       v.resize(self.planes().size());
> > +                       transform(self.planes().begin(), self.planes().end(), v.begin(), [](const auto &p) { return p.bytesused; });
> > +                       return v;
> > +               });
> > +}
> > diff --git a/src/py/meson.build b/src/py/meson.build
> > new file mode 100644
> > index 00000000..4ce9668c
> > --- /dev/null
> > +++ b/src/py/meson.build
> > @@ -0,0 +1 @@
> > +subdir('libcamera')
> > diff --git a/subprojects/.gitignore b/subprojects/.gitignore
> > index 391fde2c..0e194289 100644
> > --- a/subprojects/.gitignore
> > +++ b/subprojects/.gitignore
> > @@ -1,3 +1,4 @@
> >  /googletest-release*
> >  /libyuv
> > -/packagecache
> > \ No newline at end of file
> > +/packagecache
> > +/pybind11
> > diff --git a/subprojects/packagefiles/pybind11/meson.build b/subprojects/packagefiles/pybind11/meson.build
> > new file mode 100644
> > index 00000000..67e89aec
> > --- /dev/null
> > +++ b/subprojects/packagefiles/pybind11/meson.build
> > @@ -0,0 +1,8 @@
> > +project('pybind11', 'cpp',
> > +        version : '2.9.1',
> > +        license : 'BSD-3-Clause')
> > +
> > +pybind11_incdir = include_directories('include')
> > +
> > +pybind11_dep = declare_dependency(
> > +  include_directories : pybind11_incdir)

4 spaces for indentation.

> > diff --git a/subprojects/pybind11.wrap b/subprojects/pybind11.wrap
> > new file mode 100644
> > index 00000000..2413e9ca
> > --- /dev/null
> > +++ b/subprojects/pybind11.wrap
> > @@ -0,0 +1,8 @@
> > +[wrap-git]
> > +url = https://github.com/pybind/pybind11.git

A comment here to mention this is the smart_holder branch could be nice.

> > +revision = 82734801f23314b4c34d70a79509e060a2648e04
> 
> Great - this is now pointing directly to the pybind sources so I think
> that's much cleaner:
> 
> It's hard to do a dedicated review on so much that I honestly don't
> fully comprehend yet - but I think getting this in and working/building
> on top is better for everyone, and as far as I know - it's already quite
> well tested by RPi (albeit, an older version, so I hope David can rebase
> and test sometime soon).
> 
> 
> Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
> 
> > +depth = 1
> > +patch_directory = pybind11

Do we actually have any patch ?

All comments are minor, once addressed,

Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

> > +
> > +[provide]
> > +pybind11 = pybind11_dep

-- 
Regards,

Laurent Pinchart


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