[libcamera-devel] [PATCH v2] Add enable_auto_focus option to the GStreamer plugin
Nicolas Dufresne
nicolas at ndufresne.ca
Mon Jun 5 17:56:56 CEST 2023
Le lundi 05 juin 2023 à 18:33 +0300, Laurent Pinchart a écrit :
> Hi Cedric,
>
> (CC'ing Nicolas)
>
> Thank you for the patch.
>
> On Mon, Jun 05, 2023 at 04:44:05PM +0200, Cedric Nugteren via libcamera-devel wrote:
> > Cameras such as the PiCam 3 support auto-focus, but the GStreamer plugin
> > for libcamera does not enable auto-focus. With this patch auto-focus can
> > be enabled for cameras that support it. By default it is disabled, which
> > means default behaviour remains unchanged. For cameras that do not
> > support auto-focus, an error message shows up if it auto-focus is
>
> I think you meant "its auto-focus" instead of "it auto-focus" ?
>
> > enabled.
> >
> > This was tested on cameras that do not support auto-focus (e.g. PiCam2)
> > and was tested on a camera that does support auto-focus (PiCam3) by
> > enabling it, observing auto-focus, and by disabling it or by not setting
> > the option, both resulting in auto-focus being disabled.
> >
> > This should close https://bugs.libcamera.org/show_bug.cgi?id=188.
>
> This should be written
>
> Bug: https://bugs.libcamera.org/show_bug.cgi?id=188.
>
> which I realize isn't documented anywhere :-S I wonder where to best
> mention this. Is there any particular place in the documentation that
> would have caught your eyes ?
>
> > Signed-off-by: Cedric Nugteren <web at cedricnugteren.nl>
> > ---
> > Changes since v1:
> > - Now re-using the GParamSpec variables instead of re-creating.
> > - Use bool instead of gboolean for enable_auto_focus.
> > - Remove changes from the reconfigure_element functions.
>
> Perfect :-)
>
> > ---
> > src/gstreamer/gstlibcameraprovider.cpp | 12 +++++++++++
> > src/gstreamer/gstlibcamerasrc.cpp | 29 +++++++++++++++++++++++++-
> > 2 files changed, 40 insertions(+), 1 deletion(-)
> >
> > diff --git a/src/gstreamer/gstlibcameraprovider.cpp b/src/gstreamer/gstlibcameraprovider.cpp
> > index 6eb0a0eb..579cb8c0 100644
> > --- a/src/gstreamer/gstlibcameraprovider.cpp
> > +++ b/src/gstreamer/gstlibcameraprovider.cpp
> > @@ -31,6 +31,7 @@ GST_DEBUG_CATEGORY_STATIC(provider_debug);
> >
> > enum {
> > PROP_DEVICE_NAME = 1,
> > + PROP_ENABLE_AUTO_FOCUS = 2,
> > };
> >
> > #define GST_TYPE_LIBCAMERA_DEVICE gst_libcamera_device_get_type()
> > @@ -40,6 +41,7 @@ G_DECLARE_FINAL_TYPE(GstLibcameraDevice, gst_libcamera_device,
> > struct _GstLibcameraDevice {
> > GstDevice parent;
> > gchar *name;
> > + bool enable_auto_focus = false;
> > };
> >
> > G_DEFINE_TYPE(GstLibcameraDevice, gst_libcamera_device, GST_TYPE_DEVICE)
> > @@ -56,6 +58,7 @@ gst_libcamera_device_create_element(GstDevice *device, const gchar *name)
> > g_assert(source);
> >
> > g_object_set(source, "camera-name", GST_LIBCAMERA_DEVICE(device)->name, nullptr);
> > + g_object_set(source, "enable-auto-focus", GST_LIBCAMERA_DEVICE(device)->enable_auto_focus, nullptr);
>
> Nicolas, is there any particular rule when it comes to naming properties
> for GStreamer elements ?
The GLib part of it is:
A property name consists of one or more segments consisting of ASCII letters and
digits, separated by either the - or _ character. The first character of a
property name must be a letter. These are the same rules as for signal naming
(see g_signal_new()).
I strongly prefer - instead of _. Generally speaking, I would like this
discussion to happen before we start adding controls. One of the thing I was
considering was to auto-generate the propertly from the yaml, and clearly this
one is not a 1:1 mapping to the libcamera controls. But at the same time, there
is bunch of needed exception for semantic reasons. The yaml is not descriptive
enough to configure fully the properties unfortunately.
As its easier to express what I'm hoping for with code, here's my own WIP, which
is much more C++ like then this one. I'm missing the AutoFocusMode.
https://gitlab.collabora.com/nicolas/libcamera/-/commit/83d67744ccbd60ad67d2afc70be7f2d95032e4d7
Nicolas
>
> >
> > return source;
> > }
> > @@ -82,6 +85,9 @@ gst_libcamera_device_set_property(GObject *object, guint prop_id,
> > case PROP_DEVICE_NAME:
> > device->name = g_value_dup_string(value);
> > break;
> > + case PROP_ENABLE_AUTO_FOCUS:
> > + device->enable_auto_focus = g_value_get_boolean(value);
> > + break;
> > default:
> > G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
> > break;
> > @@ -121,6 +127,12 @@ gst_libcamera_device_class_init(GstLibcameraDeviceClass *klass)
> > (GParamFlags)(G_PARAM_STATIC_STRINGS | G_PARAM_WRITABLE |
> > G_PARAM_CONSTRUCT_ONLY));
> > g_object_class_install_property(object_class, PROP_DEVICE_NAME, pspec);
> > + pspec = g_param_spec_boolean("enable-auto-focus",
> > + "Enable auto-focus",
> > + "Enable auto-focus if set to true, "
> > + "disable it if set to false",
> > + FALSE, G_PARAM_WRITABLE);
>
> Incorrect indentation (you should use tabs instead of spaces, and the
> last line is indented by one space too much.
>
> We have a tool, in utils/checkstyle.py, that checks for common coding
> style violations and can in many cases propose fixes (see
> https://libcamera.org/coding-style.html#tools). I recommend installing
> it as a git post-commit hook, how to do so is also documented in the
> previous URL.
>
> Please take the output of the tool with a pinch of salt though. For code
> formatting, the tool is based on clang-format, and while it does a
> fairly good job, not all suggestions are perfect. You can ignore some of
> the warnings if you think that's appropriate (mostly based on the coding
> style of the existing code in the file).
>
> > + g_object_class_install_property(object_class, PROP_ENABLE_AUTO_FOCUS, pspec);
> > }
> >
> > static GstDevice *
> > diff --git a/src/gstreamer/gstlibcamerasrc.cpp b/src/gstreamer/gstlibcamerasrc.cpp
> > index a10cbd4f..b2d8456b 100644
> > --- a/src/gstreamer/gstlibcamerasrc.cpp
> > +++ b/src/gstreamer/gstlibcamerasrc.cpp
> > @@ -146,6 +146,7 @@ struct _GstLibcameraSrc {
> > GstTask *task;
> >
> > gchar *camera_name;
> > + bool enable_auto_focus = false;
> >
> > GstLibcameraSrcState *state;
> > GstLibcameraAllocator *allocator;
> > @@ -154,7 +155,8 @@ struct _GstLibcameraSrc {
> >
> > enum {
> > PROP_0,
> > - PROP_CAMERA_NAME
> > + PROP_CAMERA_NAME,
> > + PROP_ENABLE_AUTO_FOCUS,
> > };
> >
> > G_DEFINE_TYPE_WITH_CODE(GstLibcameraSrc, gst_libcamera_src, GST_TYPE_ELEMENT,
> > @@ -577,6 +579,18 @@ gst_libcamera_src_task_enter(GstTask *task, [[maybe_unused]] GThread *thread,
> > gst_flow_combiner_add_pad(self->flow_combiner, srcpad);
> > }
> >
> > + if (self->enable_auto_focus) {
> > + const ControlInfoMap &infoMap = state->cam_->controls();
> > + if (infoMap.find(&controls::AfMode) != infoMap.end()) {
> > + state->initControls_.set(controls::AfMode, controls::AfModeContinuous);
> > + } else {
> > + GST_ELEMENT_ERROR(self, RESOURCE, SETTINGS,
> > + ("Failed to enable auto focus"),
> > + ("AfMode not found in camera controls, "
> > + "please retry with 'enable-auto-focus=false'"));
> > + }
> > + }
>
> We should be able to enable and disable auto-focus at runtime as well. I
> don't want to ask for too much yak-shaving, so I'm fine with this patch
> as an initial solution. Please note, however, that once we enable
> support for controls more generically in libcamerasrc, the name of the
> property may change.
>
> > +
> > ret = state->cam_->start(&state->initControls_);
> > if (ret) {
> > GST_ELEMENT_ERROR(self, RESOURCE, SETTINGS,
> > @@ -659,6 +673,9 @@ gst_libcamera_src_set_property(GObject *object, guint prop_id,
> > g_free(self->camera_name);
> > self->camera_name = g_value_dup_string(value);
> > break;
> > + case PROP_ENABLE_AUTO_FOCUS:
> > + self->enable_auto_focus = g_value_get_boolean(value);
> > + break;
> > default:
> > G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
> > break;
> > @@ -676,6 +693,9 @@ gst_libcamera_src_get_property(GObject *object, guint prop_id, GValue *value,
> > case PROP_CAMERA_NAME:
> > g_value_set_string(value, self->camera_name);
> > break;
> > + case PROP_ENABLE_AUTO_FOCUS:
> > + g_value_set_boolean(value, self->enable_auto_focus);
> > + break;
> > default:
> > G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
> > break;
> > @@ -844,4 +864,11 @@ gst_libcamera_src_class_init(GstLibcameraSrcClass *klass)
> > | G_PARAM_READWRITE
> > | G_PARAM_STATIC_STRINGS));
> > g_object_class_install_property(object_class, PROP_CAMERA_NAME, spec);
> > + spec = g_param_spec_boolean("enable-auto-focus",
> > + "Enable auto-focus",
> > + "Enable auto-focus if set to true, "
> > + "disable it if set to false",
> > + FALSE, G_PARAM_WRITABLE);
> > + g_object_class_install_property(object_class, PROP_ENABLE_AUTO_FOCUS, spec);
> > +
> > }
>
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