Implement a new memory type wrapping CVPixelBuffer.
There are two immediate advantages:
a) Make the GstMemory itself retain the CVPixelBuffer. Previously,
the containing GstBuffer was solely responsible for the lifetime of
the backing CVPixelBuffer.
With this change, we remove the GST_MEMORY_FLAG_NO_SHARE so that
GstMemory objects be referenced by multiple GstBuffers (doing away
with the need to copy.)
b) Delay locking CVPixelBuffer into CPU memory until it's actually
mapped -- possibly never.
The CVPixelBuffer object is shared among references, shares and
(in planar formats) planes, so a wrapper GstAppleCoreVideoPixelBuffer
structure was introduced to manage locking.
https://bugzilla.gnome.org/show_bug.cgi?id=747216
When doing GLMemory avfvideosrc negotiates UYVY. This change allows avfvideosrc
! tee name=t ! ... ! glimagesink t. ! ... ! gldownload ! vtenc_h264 ! ...
to do GLMemory and 0-copy with the encoder (with the CV meta).
Change texture format from BGRA to NV12. This allows a pipeline like avfvideosrc
! tee name=t ! ... ! glimagesink t. ! ... ! gldownload ! vtenc_h264 ! ... to
negotiate GLMemory. This makes the glimagesink branch much faster (obviously)
and triggers the 0-copy path between avfvideosrc and vtenc (using the CV meta).
Combined this results in a huge perf improvement on iOS (25-30% of CPU time in a
pipeline like the one above).
Note that this doesn't introduce a new shader conversion in the sink, since BGRA
textures had to be copied/converted from format=BGRA,texture-target=RECTANGLE to
format=RGBA,texture-target=2D anyway.
Fixate to the highest possible resolution and fps. Otherwise by default we end
up fixating at 2fps and the lowest supported resolution, which is hardly what
someone who bought an overpriced smartphone wants.
We need a static lock to protect various NVENC methods in _set_format(). Without
this the CPU use increases dramatically on initialisation of the element when
there are multiple elements being initialised at the same time.
https://bugzilla.gnome.org/show_bug.cgi?id=759742
When the mode of decklinkvideosink is set to "auto", the sink claims to
support the full set of caps that it can support for all modes. Then, every
time new caps are set, the sink will automatically find the correct mode for
these caps and set it.
Caveat: We have no way to know whether a specific mode will actually work for
your hardware. Therefore, if you try sending 4K video to a 1080 screen, it
will silently fail, we have no way to know that in advance. Manually setting
that mode at least gave the user a way to double-check what they are doing.
https://bugzilla.gnome.org/show_bug.cgi?id=759600
Otherwise qtkitvideosrc fails to build on OSX 10.10.4
because QTKit has been deprecated since OS X 10.9.
Also set -mmacosx-version-min=10.8 in front to allow
the user or cerbero to override the version.
https://bugzilla.gnome.org/show_bug.cgi?id=745564
