[Bug 779484] New: Allow start_preroll to be overridden

["GStreamer" (GNOME Bugzilla)]

https://bugzilla.gnome.org/show_bug.cgi?id=779484

Bug ID: 779484
Summary: Allow start_preroll to be overridden
Classification: Platform
Product: GStreamer
Version: 1.11.1
OS: Mac OS
Status: NEW
Severity: enhancement
Priority: Normal
Component: gst-rtsp-server
Assignee: gstreamer-***@lists.freedesktop.org
Reporter: ***@gmail.com
QA Contact: gstreamer-***@lists.freedesktop.org
GNOME version: ---

In order to build videocompositor/mosaic RTSP server, I subclassed
RTSPMediaFactory to create my own elements directly. Each RTSPMedia created by
the factory is in the same pipeline (so they can mux together). But RTSPMedia
does not allow you to share pipelines between Media elements, because as part
of the preparation process it prerolls the pipeline: it sets the pipeline state
to pause and then it listens for confirmation that it transitioned from ready
-> pause before activating everything. But if you are sharing a pipeline
between RTSPMedia it will already be in state playing most of the time, and new
medias that share the pipeline will not get prepared correctly.

My solution is to make the preroll method overridable.

I wanted some feedback on this before I continue...

["GStreamer" (GNOME Bugzilla)]

https://bugzilla.gnome.org/show_bug.cgi?id=779484

Nick Kallen <***@gmail.com> changed:

What |Removed |Added
----------------------------------------------------------------------------
CC| |***@coaxion.net

["GStreamer" (GNOME Bugzilla)]

https://bugzilla.gnome.org/show_bug.cgi?id=779484

--- Comment #1 from Nick Kallen <***@gmail.com> ---
Created attachment 347086
--> https://bugzilla.gnome.org/attachment.cgi?id=347086&action=edit
Allow override of preroll

["GStreamer" (GNOME Bugzilla)]

https://bugzilla.gnome.org/show_bug.cgi?id=779484

Nick Kallen <***@gmail.com> changed:

What |Removed |Added
----------------------------------------------------------------------------
Summary|Allow start_preroll to be |Allow pipelines to be
|overridden |shared between media

["GStreamer" (GNOME Bugzilla)]

https://bugzilla.gnome.org/show_bug.cgi?id=779484

--- Comment #2 from Nick Kallen <***@gmail.com> ---
Created attachment 347193
--> https://bugzilla.gnome.org/attachment.cgi?id=347193&action=edit
Add setting to indicate pipeline is shared; Media do not manipulate state of
shared-pipelines

I like this approach better although the change is more drastic.

There is a new setting, 'shared-pipeline', that tells the media not to
manipulate the pipeline's state nor rely on the pipeline's state changes (e.g.,
in handle_message) for its own internal state. This allows different media to
share a live pipeline.

In order for this to work correctly, the media needs to manipulate the state of
its rtpbin and the various elements added by the stream, which would otherwise
have inherited the state changes from the pipeline. To keep the code simple,
these elements are added to the bin the user provides (i.e., the media's
element) rather than adding them to the pipeline. Then simply changing the
bin's state keeps everything in sync.

I also fixed what I think was a bug in `gst_rtsp_media_unprepare`, where the
media would never be unprepared if it was in the suspend state, but going into
the suspend state is a normal part of disposing of the media.

["GStreamer" (GNOME Bugzilla)]

https://bugzilla.gnome.org/show_bug.cgi?id=779484

Nicolas Dufresne (stormer) <***@ndufresne.ca> changed:

What |Removed |Added
----------------------------------------------------------------------------
CC| |***@ndufresne.ca
Summary|Allow pipelines to be |rtsp: Allow pipelines to be
|shared between media |shared between media

["GStreamer" (GNOME Bugzilla)]

https://bugzilla.gnome.org/show_bug.cgi?id=779484

GStreamer system administrator <***@gstreamer.net> changed:

What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
Resolution|--- |OBSOLETE

--- Comment #3 from GStreamer system administrator <***@gstreamer.net> ---
-- GitLab Migration Automatic Message --

This bug has been migrated to freedesktop.org's GitLab instance and has been
closed from further activity.

You can subscribe and participate further through the new bug through this link
to our GitLab instance:
https://gitlab.freedesktop.org/gstreamer/gst-rtsp-server/issues/33.