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Functions
| ClutterGstVideoSink * | clutter_gst_video_sink_new () |
| gboolean | clutter_gst_video_sink_is_ready () |
| ClutterGstFrame * | clutter_gst_video_sink_get_frame () |
| CoglPipeline * | clutter_gst_video_sink_get_pipeline () |
| void | clutter_gst_video_sink_setup_pipeline () |
| ClutterGstOverlays * | clutter_gst_video_sink_get_overlays () |
Object Hierarchy
GObject
╰── GInitiallyUnowned
╰── GstObject
╰── GstElement
╰── GstBaseSink
╰── GstVideoSink
╰── ClutterGstVideoSink
Description
ClutterGstVideoSink is a subclass of GstBaseSink which can be used to create a CoglPipeline for rendering the frames of the video.
To create a basic video player, an application can create a
GstPipeline as normal using gst_pipeline_new() and set the
sink on it to one created with clutter_gst_video_sink_new(). The
application can then listen for the “new-frame”
signal which will be emitted whenever there are new textures ready
for rendering. For simple rendering, the application can just call
clutter_gst_video_sink_get_pipeline() in the signal handler and use
the returned pipeline to paint the new frame.
An application is also free to do more advanced rendering by
customizing the pipeline. In that case it should listen for the
“pipeline-ready” signal which will be emitted as
soon as the sink has determined enough information about the video
to know how it should be rendered. In the handler for this signal,
the application can either make modifications to a copy of the
pipeline returned by clutter_gst_video_sink_get_pipeline() or it can
create its own pipeline from scratch and ask the sink to configure
it with clutter_gst_video_sink_setup_pipeline(). If a custom pipeline
is created using one of these methods then the application should
call clutter_gst_video_sink_attach_frame() on the pipeline before
rendering in order to update the textures on the pipeline's layers.
If the COGL_FEATURE_ID_GLSL feature is available then the pipeline
used by the sink will have a shader snippet with a function in it
called clutter_gst_sample_video0 which takes a single vec2 argument.
This can be used by custom snippets set the by the application to
sample from the video. The vec2 argument represents the normalised
coordinates within the video. The function returns a vec4
containing a pre-multiplied RGBA color of the pixel within the
video.
Functions
clutter_gst_video_sink_new ()
ClutterGstVideoSink *
clutter_gst_video_sink_new (void);
Creates a new ClutterGstVideoSink
Since 3.0
clutter_gst_video_sink_is_ready ()
gboolean
clutter_gst_video_sink_is_ready (ClutterGstVideoSink *sink);
Returns whether the pipeline is ready and so
clutter_gst_video_sink_get_pipeline() and
clutter_gst_video_sink_setup_pipeline() can be called without causing error.
Note: Normally an application will wait until the “pipeline-ready” signal is emitted instead of polling the ready status with this api, but sometimes when a sink is passed between components that didn't have an opportunity to connect a signal handler this can be useful.
Since 3.0
clutter_gst_video_sink_get_frame ()
ClutterGstFrame *
clutter_gst_video_sink_get_frame (ClutterGstVideoSink *sink);
Returns a ClutterGstFrame object suitable to render the current frame of the given video sink. An application is free to make a copy of this pipeline and modify it for custom rendering.
Since 3.0
clutter_gst_video_sink_get_pipeline ()
CoglPipeline *
clutter_gst_video_sink_get_pipeline (ClutterGstVideoSink *sink);
Returns a pipeline suitable for rendering the current frame of the given video sink. The pipeline will already have the textures for the frame attached. For simple rendering, an application will typically call this function immediately before it paints the video. It can then just paint a rectangle using the returned pipeline.
An application is free to make a copy of this pipeline and modify it for custom rendering.
Note: it is considered an error to call this function before the “pipeline-ready” signal is emitted.
Since 3.0
clutter_gst_video_sink_setup_pipeline ()
void clutter_gst_video_sink_setup_pipeline (ClutterGstVideoSink *sink,CoglPipeline *pipeline);
Configures the given pipeline so that will be able to render the
video for the sink
. This should only be used if the application
wants to perform some custom rendering using its own pipeline.
Typically an application will call this in response to the
“pipeline-ready” signal.
Note: it is considered an error to call this function before the “pipeline-ready” signal is emitted.
Since 3.0
clutter_gst_video_sink_get_overlays ()
ClutterGstOverlays *
clutter_gst_video_sink_get_overlays (ClutterGstVideoSink *sink);
Types and Values
struct ClutterGstVideoSink
struct ClutterGstVideoSink;
The ClutterGstVideoSink structure contains only private data and should be accessed using the provided API.
Since 3.0
struct ClutterGstVideoSinkClass
struct ClutterGstVideoSinkClass {
void (* new_frame) (ClutterGstVideoSink *sink);
void (* pipeline_ready) (ClutterGstVideoSink *sink);
void (* new_overlays) (ClutterGstVideoSink *sink);
};
Since 3.0
Signal Details
The “new-frame” signal
void user_function (ClutterGstVideoSink *sink, gpointer user_data)
The sink will emit this signal whenever there are new textures
available for a new frame of the video. After this signal is
emitted, an application can call clutter_gst_video_sink_get_pipeline()
to get a pipeline suitable for rendering the frame. If the
application is using a custom pipeline it can alternatively call
clutter_gst_video_sink_attach_frame() to attach the textures.
Flags: Run Last
Since 3.0
The “new-overlays” signal
void user_function (ClutterGstVideoSink *sink, gpointer user_data)
The sink will emit this signal whenever there are new textures
available for set of overlays on the video. After this signal is
emitted, an application can call
clutter_gst_video_sink_get_overlays() to get a set of pipelines
suitable for rendering overlays on a video frame.
Flags: Run Last
Since 3.0
The “pipeline-ready” signal
void user_function (ClutterGstVideoSink *sink, gpointer user_data)
The sink will emit this signal as soon as it has gathered enough
information from the video to configure a pipeline. If the
application wants to do some customized rendering, it can setup its
pipeline after this signal is emitted. The application's pipeline
will typically either be a copy of the one returned by
clutter_gst_video_sink_get_pipeline() or it can be a completely custom
pipeline which is setup using clutter_gst_video_sink_setup_pipeline().
Note that it is an error to call either of those functions before this signal is emitted. The “new-frame” signal will only be emitted after the pipeline is ready so the application could also create its pipeline in the handler for that.
Flags: Run Last
Since 3.0