[libcamera-devel] [PATCH v5 1/3] Add Python bindings
David Plowman
david.plowman at raspberrypi.com
Tue Apr 12 20:44:19 CEST 2022
Hi Jacopo, everyone
On our "picamera2" branch of libcamera we have all Tomi's work, plus
another 8 commits on top which implement the features that I was
missing (https://github.com/raspberrypi/libcamera/commits/picamera2).
Most of it is to do with Transforms, ColorSpaces, array controls and
one or two other things. I was planning to start submitting some of
these once the bulk of the work has been merged. Most of it shouldn't
be too surprising, though there's another
"multi-plane-isn't-really-multi-plane" thing (just like we had in the
C++ world some time ago) which needs a proper solution.
David
On Tue, 12 Apr 2022 at 18:49, Jacopo Mondi <jacopo at jmondi.org> wrote:
>
> Hi Tomi,
> I've been using the bindings in the last days, they're nice to
> work! Great job!
>
> Once the question about a Request belonging to a Camera is
> clarified I think we should merge these soon, even if incomplete, to
> build on top.
>
> My understanding of python is very limited so I have just a few minor
> comments and one larger question about controls.
>
> On Mon, Mar 14, 2022 at 05:46:31PM +0200, Tomi Valkeinen via libcamera-devel wrote:
> > 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 | 10 +
> > src/py/libcamera/meson.build | 43 ++++
> > src/py/libcamera/pyenums.cpp | 53 ++++
> > src/py/libcamera/pymain.cpp | 453 +++++++++++++++++++++++++++++++++++
> > src/py/meson.build | 1 +
> > subprojects/.gitignore | 3 +-
> > subprojects/pybind11.wrap | 6 +
> > 10 files changed, 575 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/pybind11.wrap
> >
> > diff --git a/meson.build b/meson.build
> > index 29d8542d..ff6c2ad6 100644
> > --- a/meson.build
> > +++ b/meson.build
> > @@ -179,6 +179,7 @@ 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..b30bf33a
> > --- /dev/null
> > +++ b/src/py/libcamera/__init__.py
> > @@ -0,0 +1,10 @@
> > +# SPDX-License-Identifier: LGPL-2.1-or-later
> > +# Copyright (C) 2021, Tomi Valkeinen <tomi.valkeinen at ideasonboard.com>
> > +
> > +from ._libcamera import *
> > +import mmap
> > +
> > +def __FrameBuffer__mmap(self, plane):
> > + 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..82388efb
> > --- /dev/null
> > +++ b/src/py/libcamera/meson.build
> > @@ -0,0 +1,43 @@
> > +# 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',
> > +])
> > +
> > +pycamera_deps = [
> > + libcamera_public,
> > + py3_dep,
> > + pybind11_dep,
> > +]
> > +
> > +pycamera_args = ['-fvisibility=hidden']
> > +pycamera_args += ['-Wno-shadow']
> > +pycamera_args += ['-DPYBIND11_USE_SMART_HOLDER_AS_DEFAULT']
> > +
> > +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')
> > +
> > +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..af6151c8
> > --- /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
> > + */
> > +
> > +#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);
> > +
> > + 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)
> > + .value("Complete", Request::RequestComplete)
> > + .value("Cancelled", Request::RequestCancelled);
> > +
> > + py::enum_<FrameMetadata::Status>(m, "FrameMetadataStatus")
> > + .value("Success", FrameMetadata::FrameSuccess)
> > + .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)
> > + .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..7701da40
> > --- /dev/null
> > +++ b/src/py/libcamera/pymain.cpp
> > @@ -0,0 +1,453 @@
> > +/* 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
> > + */
> > +
> > +#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/smart_holder.h>
> > +#include <pybind11/functional.h>
> > +#include <pybind11/stl.h>
> > +#include <pybind11/stl_bind.h>
> > +
> > +namespace py = pybind11;
> > +
> > +using namespace std;
> > +using namespace libcamera;
> > +
> > +template<typename T>
> > +static py::object ValueOrTuple(const ControlValue &cv)
> > +{
> > + 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: {
> > + 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:
> > + case ControlTypeNone:
> > + default:
> > + throw runtime_error("Control type not implemented");
> > + }
> > +}
> > +
> > +static weak_ptr<CameraManager> g_camera_manager;
> > +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");
> > +
> > + /* 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");
> > +
> > + 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 &) {
> > + 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() */
> > + 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);
> > +
> > + if (id.find(str) != string::npos)
> > + 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);
> > +
> > + int ret = self.start();
> > + if (ret)
> > + self.requestCompleted.disconnect(handleRequestCompleted);
> > +
> > + return ret;
> > + })
> > +
> > + .def("stop", [](Camera &self) {
> > + int ret = self.stop();
> > + if (!ret)
> > + self.requestCompleted.disconnect(handleRequestCompleted);
> > +
> > + return ret;
> > + })
> > +
> > + .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);
> > +
> > + 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) {
> > + 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()) {
> > + 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)
> > + .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); })
> > + .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 */
> > + .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()));
> > + })
>
> I see a mixture of camel case ("addBuffer") and snake case
> ("set_controls"). If there's a preferred coding style for Python
> should we uniform on it ?
>
> Minor comments apart, there's a thing which is missing:
> support for setting controls that accept a Span<> of values.
>
> I tried several solutions and I got the following to compile
>
> .def("set_control_array", [](Request &self, ControlId& id, py::tuple &values) {
> py::bytearray bytes = py::bytearray(values);
> py::buffer_info info(py::buffer(bytes).request());
>
> const int *data = reinterpret_cast<const int *>(info.ptr);
> size_t length = static_cast<size_t>(info.size);
>
> self.controls().set(id.id(), Span<const int>{data, length});
> })
>
> (All types in casts<> should depend on id.type(), but that's for later).
>
> Unfortunately, while length is correct, the values I access with
> 'data' seems invalid, which makes me think
>
> py::bytearray bytes = py::bytearray(values);
>
> Dosn't do what I think it does, or maybe Tuple in Python are simply
> not backed by a contigous memory buffer , hence there's no way to wrap
> their memory in a Span<>).
>
> Please note I also tried to instrument:
>
> .def("set_control_array", [](Request &self, ControlId& id, vector<int> values)
>
> Relying on pybind11 type casting, and it seems to work, but I see two issues:
>
> 1) Converting from python to C++ types goes through a copy.
> Performances reasons apart, the vector lifetime is limited to the
> function scope. This isn't be a problem for now, as control
> values are copied in the Request's control list, but that would
> prevent passing controls values as pointers, if a control transports a
> large chunk of data (ie gamma tables). Not sure we'll ever want this
> (I don't think so as it won't play well with serialization between the
> IPA and the pipeline handler) but you never know.
>
> 2) my understanding is that python does not support methods signature
> overloading, hence we would have
>
> .def("set_control_array_int", [](Request &self, ControlId& id, vector<int> values)
> .def("set_control_array_float", [](Request &self, ControlId& id, vector<float> values)
> ....
>
> there are surely smart ways to handle this, but in my quick experiment
> I haven't found one yet :)
>
> David: Is the issue with Span<> controls addressed by picamera2 ?
>
> Thanks, I hope we can merge this soon!
>
>
> > + .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. */
> > + .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 */
> > + .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..757bb072 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/pybind11.wrap b/subprojects/pybind11.wrap
> > new file mode 100644
> > index 00000000..ebf942ff
> > --- /dev/null
> > +++ b/subprojects/pybind11.wrap
> > @@ -0,0 +1,6 @@
> > +[wrap-git]
> > +url = https://github.com/tomba/pybind11.git
> > +revision = smart_holder
> > +
> > +[provide]
> > +pybind11 = pybind11_dep
> > --
> > 2.25.1
> >
More information about the libcamera-devel
mailing list