On Thu, Apr 24, 2025 at 10:43:21AM +0200, Dietmar Maurer wrote:
>
> > On 24.4.2025 09:32 CEST Dietmar Maurer <diet...@proxmox.com> wrote:
> >
> >
> > > > + gst_object_ref(vs->h264->source);
> > > > + if (!gst_bin_add(GST_BIN(vs->h264->pipeline), vs->h264->source)) {
> > > > + gst_object_unref(vs->h264->source);
> > > > + VNC_DEBUG("Could not add source to gst pipeline\n");
> > > > + goto error;
> > > > + }
> > >
> > > If you put the gst_object_ref call after sucessfully calling
> > > gst_bin_add, then it wouldn't need the gst_object_unref call
> > > on failure. Repeated many times below.
> >
> > Gstreamer docs claims that gst_bin_add() takes ownership of the element. So
> > I assumed that it unref the element in case of error.
> > If I do not ref the object before, this would free the object too early.
> >
> > But a look at the source code of gstbin.c reveals that it does
> > not unref the element in case of errors, so your suggestion works.
> > I will change that in the next version...
>
> From the gstreamer docs about refcounting and gst_bin_add:
>
> https://gstreamer.freedesktop.org/documentation/additional/design/MT-refcounting.html?gi-language=c#refcounting1
>
> > As soon as this function is called in a Bin, the element passed as an
> > argument is owned by the bin and you are not allowed to access it anymore
> > without taking a _ref() before adding it to the bin.
>
> This clearly states we should taking a _ref() before adding it to the bin?
Yes, you are correct, ignore my suggestion.
With regards,
Daniel
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