[libcamera-devel] [PATCH v3] gstreamer: Implement element EOS handling

[Kieran Bingham]

Quoting Laurent Pinchart via libcamera-devel (2023-11-22 16:38:49)
> Hello,
> 
> On Tue, Nov 14, 2023 at 01:18:57PM +0100, Jaslo Ziska via libcamera-devel wrote:
> > This commit implements EOS handling for events sent to the libcamerasrc
> > element by the send_event method (which can happen when pressing
> > Ctrl-C while running gst-launch-1.0 -e, see below). EOS events from
> > downstream elements returning GST_FLOW_EOS are not considered here.
> > 
> > To archive this add a function for the send_event method which handles
> > the GST_EVENT_EOS event. This function will set an atomic to the
> > received event and push this EOS event to all source pads in the running
> > task.
> > 
> > Also set the GST_ELEMENT_FLAG_SOURCE flag to identify libcamerasrc as a
> > source element which enables it to receive EOS events sent to the
> > (pipeline) bin containing it.
> > This in turn enables libcamerasrc to for example receive EOS events from
> > gst-launch-1.0 when using the -e flag.
> > 
> > Bug: https://bugs.libcamera.org/show_bug.cgi?id=91
> > Signed-off-by: Jaslo Ziska <jaslo at ziska.de>
> > Acked-by: Nicolas Dufresne <nicolas.dufresne at collabora.com>
> > ---
<snip>

> > +static gboolean
> > +gst_libcamera_src_send_event(GstElement *element, GstEvent *event)
> > +{
> > +     GstLibcameraSrc *self = GST_LIBCAMERA_SRC(element);
> > +     gboolean ret = FALSE;
> > +
> > +     switch (GST_EVENT_TYPE(event)) {
> > +     case GST_EVENT_EOS: {
> > +             g_autoptr(GstEvent) oldEvent = self->pending_eos.exchange(event);
> 
> I'm afraid this causes a compilation breakage with clang :-(
> 
> ../../src/gstreamer/gstlibcamerasrc.cpp:768:23: error: unused variable 'oldEvent' [-Werror,-Wunused-variable]
>                 g_autoptr(GstEvent) oldEvent = self->pending_eos.exchange(event);
>                                     ^
> 
> The patch has been merged, can you propose a fix quickly, or should I
> revert to give you more time ?
> 

I'm afraid with a broken build we're blocked on merging more patches -
of which I'm now trying to do - so I'd probably ask if we can revert
this until it's fixed please.

--
Kieran