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
CMBlockBufferGetDataLength would return the entire data length, while
size of individual blocks can be smaller. Iterate over the block buffer
and add the individual (possibly non-contiguous) memory blocks.
https://bugzilla.gnome.org/show_bug.cgi?id=751071
When doing texture sharing we don't need to call CVPixelBufferLockBaseAddress to
map the buffer in CPU. This cuts about 10% relative cpu time from a vtdec !
glimagesink pipeline.
Handle stride alignment through the use of the video meta API. The
code is based on the corevideobuffer implementation.
If the video meta API is not supported and the underlying buffer
contains padding, the core media buffer is copied to a system memory
buffer.
https://bugzilla.gnome.org/show_bug.cgi?id=727885
Public frameworks don't need to build the API dynamically, we instead
use the framework directly.
The exception is for VideoToolbox which went public in the 10.8 SDK,
but it's still private in older version of the SDK and iOS. This allow
building the plugin against SDK's where it's not a public framework.
Also rename the relevant API so we mirror the public API more closely, and
switch to CoreFoundation CFTypeRef style typedefs. We still support the old
private CoreMedia in order to not break OS X support.
This means that vtenc and vtdec are now compatible with iOS 4.x, and in
theory also future versions of OS X, where this API may turn public like
it has on iOS.
Provides the following elements:
qtkitvideosrc: OS X video source relying on the QTKit API. Comes with
hard-coded caps as the API does not provide any way of querying for
formats supported by the hardware. Hasn't been tested a lot, but seems
to work.
miovideosrc: OS X video source which uses the undocumented/private
CoreMediaIOServices API, which is also the one used by iChat.
Present on latest version of Leopard and all versions of Snow Leopard.
Has been tested extensively with built-in cameras and TANDBERG's
PrecisionHD USB camera.
vtenc, vtdec: Generic codec wrappers which make use of the undocumented/
private VideoToolbox API on OS X and iOS. List of codecs are currently
hard-coded to H.264 for vtenc, and H.264 + JPEG for vtdec. Can easily be
expanded by adding new entries to the lists, but haven't yet had time to
do that. Should probably also implement probing as available codecs depend
on the OS and its version, and there doesn't seem to be any way to
enumerate the available codecs.
vth264decbin, vth264encbin: Wrapper bins to make it easier to use
vtdec_h264/vtenc_h264 in live scenarios.
iphonecamerasrc: iPhone camera source relying on the undocumented/private
Celestial API. Tested on iOS 3.1 running on an iPhone 3GS. Stops working
after a few minutes, presumably because of a resource leak. Needs some
love.
Note that the iOS parts haven't yet been ported to iOS 4.x.
