1) We need to lock and get a strong ref to the parent, if still there.
2) If it has gone away, we need to handle that gracefully.

This is necessary in order to safely modify a running pipeline. Has been
observed when a streaming thread is doing a buffer_alloc() while an
application thread sends an event on a pad further downstream, and from
within a pad probe (holding STREAM_LOCK) carries out the pipeline plumbing
while the streaming thread has its buffer_alloc() in progress.

It is possible that the element might be going down while the event arrives

https://bugzilla.gnome.org/show_bug.cgi?id=646924

The endianness was not set correctly before.

Fixes bug #646923.

The RFF flag is to be reused for buffers in the telecine state to
indicate that the buffer contains only unneeded repeated fields that are
present in other buffers and as such this buffer can be dropped.

... which avoids crashing in the off-chance that structure == NULL.

Leave dealing with the appearance of the window when we are not playing to the
applications. We anyway want to go to NULL as quickly as possible.

Fixes #635800

gstvorbistag.c: In function 'gst_tag_list_from_vorbiscomment_buffer':
gstvorbistag.c:371: warning: 'data' may be used uninitialized in this function

https://bugzilla.gnome.org/show_bug.cgi?id=646744

https://bugzilla.gnome.org/show_bug.cgi?id=646744

https://bugzilla.gnome.org/show_bug.cgi?id=646744

From 1ccbe09 to c3cafe1

A race was observed between query() and setcaps() where the latter would
change the ringbuffer spec while the former was performing operations
based this data.

Observed a case where the src went to null-state during the query,
hence the spec pointer was no longer valid, and
gst_util_unit64_scale_int crashed (assertion `denom > 0´failed)

Add locking to make sure the ringbuffer can't disappear.

Given a large enough drift-tolerance, one could end up in a situation
where one would keep aligning the written buffers behind the current
read-segment position. The result for the reader would be complete
silence, possible preceded by very choppy audio.

By checking the available headroom, one can determine if there is
room to do alignment, or if one should resort to a resync instead to get
the pointers back on track.

Also refactor the alignment-logic out of the render function for cleaner
code.

Perform calculation in a temp var with enough room as there's guarantee that
ret will be able to hold the result for example in _blit_AYUV.

This is the official, standardized way of embedding images into
vorbiscomments now.

This is the official, standardized way of embedding pictures
inside vorbiscomments now. Parsing code taken from flacparse
and slightly changed.

Fixes bug #635669.

Instead of using the GLib base64 decoding functions manually to
do inplace base64 decoding. This makes the code easier to understand.

Also initialize it always in TIME format. We require TIME segments
in oggmux anyway and drop newsegment events in other formats and
assume an open-ended segment starting at 0.

Theora and vorbis use running time (which is correct) for calculating
the granulepos for their ogg packets. Oggmux, however, used
timestamps to order the received buffers.

This patch makes it use the running time to compare buffer times
and also to timestamp pushed buffers.

Some bits of the code still use timestamps, but they are only
used to calculate durations, so it should be fine.

https://bugzilla.gnome.org/show_bug.cgi?id=643775

https://bugzilla.gnome.org/show_bug.cgi?id=643775

Now all RGB variants are supported.

'A OVER B' compositing is explained at
http://en.wikipedia.org/wiki/Alpha_compositing.

Previously, overlaying text on a transparent background image left the
text overlay also transparent. This pipeline shows such an example:

gst-launch videotestsrc pattern=white ! video/x-raw-yuv,format=\(fourcc\)AYUV ! alpha alpha=0.0 ! textoverlay text=Testing auto-resize=False font-desc=60px ! videomixer ! ffmpegcolorspace ! autovideosink

With this patch, text is composited "OVER" the background image and
thus is visible regardless of the alpha of the background image. The
overlay in the above pipeline works after applying this patch.

Commit ba2e500b ensured to provide
a running clock when EOS had finished rendering.  However,
other measures are needed (and were in place before) to ensure a
running clock when EOS still needs rendering (i.e. waiting).

So, specifically, re-introduce eos_rendering removed in aforementioned commit,
this time as a public variable so subclasses can be aware of the situation.

Fixes (part of) #645961.

API: GstBaseAudioSink:eos_rendering