[libcamera-devel] [PATCH 01/13] gstreamer: Use gst_task_resume() when available

[Vedant Paranjape]

Hello Laurent,

On Mon, Jun 27, 2022 at 9:00 PM Laurent Pinchart
<laurent.pinchart at ideasonboard.com> wrote:
>
> Hi Vedant,
>
> On Mon, Jun 27, 2022 at 08:10:04PM +0200, Vedant Paranjape wrote:
> > Hello Laurent,
> >
> > I am not sure if I am well versed enough in gstreaner to review this,
> > but here are few of my comments, pardon me if they are wrong ;)
>
> Reviews are always appreciated :-)
>
> > On Fri, Jun 24, 2022 at 1:22 AM Laurent Pinchart wrote:
> > >
> > > The gst_libcamera_resume_task() helper is an implementation of the
> > > gst_task_resume() function that predates its addition to GStreamer. Use
> > > gst_task_resume() when available, and rename gst_libcamera_resume_task()
> > > to gst_task_resume() to support older GStreamer versions.
> > >
> > > Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

Reviewed-by: Vedant Paranjape <vedantparanjape160201 at gmail.com>

> > > ---
> > >  src/gstreamer/gstlibcamera-utils.cpp | 16 ++++++++++------
> > >  src/gstreamer/gstlibcamera-utils.h   |  4 +++-
> > >  src/gstreamer/gstlibcamerasrc.cpp    |  4 ++--
> > >  3 files changed, 15 insertions(+), 9 deletions(-)
> > >
> > > diff --git a/src/gstreamer/gstlibcamera-utils.cpp b/src/gstreamer/gstlibcamera-utils.cpp
> > > index 3f2422863c03..c97c0d438de2 100644
> > > --- a/src/gstreamer/gstlibcamera-utils.cpp
> > > +++ b/src/gstreamer/gstlibcamera-utils.cpp
> > > @@ -224,16 +224,20 @@ gst_libcamera_configure_stream_from_caps(StreamConfiguration &stream_cfg,
> > >         stream_cfg.size.height = height;
> > >  }
> > >
> > > -void
> > > -gst_libcamera_resume_task(GstTask *task)
> > > +#if !GST_CHECK_VERSION(1, 17, 1)
> > > +gboolean
> > > +gst_task_resume(GstTask *task)
> > >  {
> > >         /* We only want to resume the task if it's paused. */
> > >         GLibLocker lock(GST_OBJECT(task));
> > > -       if (GST_TASK_STATE(task) == GST_TASK_PAUSED) {
> > > -               GST_TASK_STATE(task) = GST_TASK_STARTED;
> > > -               GST_TASK_SIGNAL(task);
> > > -       }
> > > +       if (GST_TASK_STATE(task) != GST_TASK_PAUSED)
> > > +               return FALSE;
> > > +
> > > +       GST_TASK_STATE(task) = GST_TASK_STARTED;
> > > +       GST_TASK_SIGNAL(task);
> > > +       return TRUE;
> > >  }
> > > +#endif
> >
> > I had a small doubt, shouldn't this replicate the function defined
> > here ? https://gitlab.freedesktop.org/gstreamer/gstreamer/blob/1.18.4/gst/gsttask.c#L865
>
> Ideally, yes, but that calls gst_task_set_state_unlocked(), which is an
> internal static function. I could copy its code here too, but as far as
> I understand, the above implementation should be functionally equivalent
> for our use cases (I think that was Nicolas' intent at least).

Ah, this makes sense.

>
> > >  G_LOCK_DEFINE_STATIC(cm_singleton_lock);
> > >  static std::weak_ptr<CameraManager> cm_singleton_ptr;
> > > diff --git a/src/gstreamer/gstlibcamera-utils.h b/src/gstreamer/gstlibcamera-utils.h
> > > index d54f15885d0c..164189a28965 100644
> > > --- a/src/gstreamer/gstlibcamera-utils.h
> > > +++ b/src/gstreamer/gstlibcamera-utils.h
> > > @@ -18,7 +18,9 @@ GstCaps *gst_libcamera_stream_formats_to_caps(const libcamera::StreamFormats &fo
> > >  GstCaps *gst_libcamera_stream_configuration_to_caps(const libcamera::StreamConfiguration &stream_cfg);
> > >  void gst_libcamera_configure_stream_from_caps(libcamera::StreamConfiguration &stream_cfg,
> > >                                               GstCaps *caps);
> > > -void gst_libcamera_resume_task(GstTask *task);
> > > +#if !GST_CHECK_VERSION(1, 17, 1)
> > > +gboolean gst_task_resume(GstTask *task);
> > > +#endif
> > >  std::shared_ptr<libcamera::CameraManager> gst_libcamera_get_camera_manager(int &ret);
> > >
> > >  /**
> > > diff --git a/src/gstreamer/gstlibcamerasrc.cpp b/src/gstreamer/gstlibcamerasrc.cpp
> > > index 46fd02d207be..9d6be075a474 100644
> > > --- a/src/gstreamer/gstlibcamerasrc.cpp
> > > +++ b/src/gstreamer/gstlibcamerasrc.cpp
> > > @@ -192,7 +192,7 @@ GstLibcameraSrcState::requestCompleted(Request *request)
> > >                 gst_libcamera_pad_queue_buffer(srcpad, buffer);
> > >         }
> > >
> > > -       gst_libcamera_resume_task(this->src_->task);
> > > +       gst_task_resume(src_->task);
> > >  }
> > >
> > >  static bool
> > > @@ -453,7 +453,7 @@ gst_libcamera_src_task_enter(GstTask *task, [[maybe_unused]] GThread *thread,
> > >                 GstLibcameraPool *pool = gst_libcamera_pool_new(self->allocator,
> > >                                                                 stream_cfg.stream());
> > >                 g_signal_connect_swapped(pool, "buffer-notify",
> > > -                                        G_CALLBACK(gst_libcamera_resume_task), task);
> > > +                                        G_CALLBACK(gst_task_resume), task);
> > >
> > >                 gst_libcamera_pad_set_pool(srcpad, pool);
> > >                 gst_flow_combiner_add_pad(self->flow_combiner, srcpad);
>
> --
> Regards,
>
> Laurent Pinchart