[GStreamer] AudioSourceProvider support in the MediaPlayer
https://bugs.webkit.org/show_bug.cgi?id=78883

Reviewed by Gustavo Noronha Silva.

GStreamer-based audio source provider for the GTK and EFL
ports. This new component gathers decoded raw audio data from the
MediaPlayer and pipes it to an AudioBus when required by the
User Agent.

* PlatformEfl.cmake: New files in the build.
* PlatformGTK.cmake: Ditto.
* platform/audio/gstreamer/AudioSourceProviderGStreamer.cpp: Added.
(WebCore::onAppsinkNewBufferCallback): Function called when a new
buffer can be pulled from appsink.
(WebCore::onGStreamerDeinterleavePadAddedCallback): Function
called when a new source pad has been added to deinterleave.
(WebCore::onGStreamerDeinterleaveReadyCallback): Function called
when the deinterleave element completed the configuration of all
its source pads.
(WebCore::copyGstreamerBuffersToAudioChannel): Called for each
channel of the AudioBus that needs data as input.
(WebCore::AudioSourceProviderGStreamer::AudioSourceProviderGStreamer):
Create an audio bin that by default routes buffers only to
autoaudiosink. A new route is added if the provider has a client.
(WebCore::AudioSourceProviderGStreamer::~AudioSourceProviderGStreamer):
Clean buffer adapters and audio bin.
(WebCore::AudioSourceProviderGStreamer::configureAudioBin):
(WebCore::AudioSourceProviderGStreamer::provideInput): Transfer
data from the buffer adapters to the bus channels.
(WebCore::AudioSourceProviderGStreamer::handleAudioBuffer): Pull a
buffer from appsink and queue it to the buffer adapter.
(WebCore::AudioSourceProviderGStreamer::setClient): Complete the
construction of the audio bin by adding a new chain to the tee
element. This new chain will deinterleave the buffer stream to
planar audio channels and route them to an appsink per channel for
data extraction.
(WebCore::AudioSourceProviderGStreamer::handleNewDeinterleavePad):
A new appsink after a new source pad has been added to deinterleave.
(WebCore::AudioSourceProviderGStreamer::deinterleavePadsConfigured):
Configure the client Node format (number of channels and sample
rate) once the provider knows how many audio channels are managed
by the pipeline.
(WebCore::cleanUpElementsAfterDeinterleaveSourcePadCallback):
(WebCore::AudioSourceProviderGStreamer::cleanUpElementsAfterDeinterleaveSourcePad):
Remove the elements after the given deinterleave source pad.
(WebCore::AudioSourceProviderGStreamer::reset): Cleanup the
deinterleave source pads. This is especially needed before the
whole pipeline goes to NULL and later on prerolls again.
* platform/audio/gstreamer/AudioSourceProviderGStreamer.h: Added.
(WebCore::AudioSourceProviderGStreamer::create): Use this to
create the provider and get an OwnPtr of it.
(WebCore::AudioSourceProviderGStreamer::client): Provider client getter.
(WebCore::AudioSourceProviderGStreamer::getAudioBin): Audio bin
getter, used by the media player to configure its
playbin::audio-sink property.
* platform/graphics/gstreamer/GRefPtrGStreamer.cpp:
* platform/graphics/gstreamer/MediaPlayerPrivateGStreamer.cpp:
(WebCore::MediaPlayerPrivateGStreamer::MediaPlayerPrivateGStreamer):
Provider life cycle management and reset the audio provider before
going to NULL.
(WebCore::MediaPlayerPrivateGStreamer::~MediaPlayerPrivateGStreamer): Ditto.
(WebCore::MediaPlayerPrivateGStreamer::handlePluginInstallerResult): Ditto.
(WebCore::MediaPlayerPrivateGStreamer::cancelLoad): Ditto.
(WebCore::MediaPlayerPrivateGStreamer::didEnd): Ditto.
(WebCore::MediaPlayerPrivateGStreamer::createAudioSink): Configure
the audio source provider if needed.
* platform/graphics/gstreamer/MediaPlayerPrivateGStreamer.h:
(WebCore::MediaPlayerPrivateGStreamer::audioSourceProvider):
Provider getter, used by MediaPlayer and MediaElement.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@177058 268f45cc-cd09-0410-ab3c-d52691b4dbfc