gst_v4l2_open() is called by gst_v4l2_device_provider_probe_device(),
where the GstV4l2Object is created without an associated GstElement.
If gst_v4l2_open() fails, it raises a bus message, but without an
element, a precondition check fails on
gst_element_message_full_with_details() generating a crash if running
with fatal-warnings debug mode.
GstV4l2Error is a helper to raise error bus messages when it is
appropiated. This patch changes the direct bus messages to this
helper, and the elements will actually send the error message.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-good/-/merge_requests/694>
This is problematic in the current design at it seriously slow down
startup of applications. As of now, no known application uses the
colorimetry and the interlace-modes for anything (the two fields that
won't be probed). So let's disable it, in the long term we'll try and
find a way to interact with the provider so applicaiton could opt-in
these slow probing methods for more advance configuration.
This way we can pass the pad name instead of the element for tracing
which helps identifying which v4l2object is used withing M2M element
like decoder, encoder and transform. For the reference, pads are name
<parent-name>:<pad-name>.
First step of a larger cleanup, all function from v4l2_calls are in fact
methods on GstV4l2Object. This split makes the code really confusing.
This also remove no longer unused macros.
Both work with autotools but they definitely don't mean the same thing, cause
problems with other build systems, and are bad form. Existence should always be
checked with #ifdef or #if defined.
The type detection would lead to assertion as it would try
to create a device without having found any type for it. It
also didn't detect MPLANE devices properly.
The same physical device can export multiple devices. In
this case, the capabilities field now contains a union of
all caps available from all exported V4L2 devices alongside
a V4L2_CAP_DEVICE_CAPS flag that should be used to decide
what capabilities to consider. In our case, we need the
ones from the exported device we are using.
https://bugzilla.gnome.org/show_bug.cgi?id=768195
Add properties to the device with exactly the same keys and sematics
as what pulseaudio uses as property keys.
Also handle the case when a device is probed manually and not through gudev.
https://bugzilla.gnome.org//show_bug.cgi?id=759780
