/* * Cogl-GStreamer. * * GStreamer integration library for Cogl. * * cogl-gst-video-sink.h - Gstreamer Video Sink that renders to a * Cogl Pipeline. * * Authored by Jonathan Matthew , * Chris Lord * Damien Lespiau * Matthew Allum * Plamena Manolova * * Copyright (C) 2007, 2008 OpenedHand * Copyright (C) 2009, 2010, 2013 Intel Corporation * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 02111-1307, USA. */ #ifndef __COGL_GST_VIDEO_SINK_H__ #define __COGL_GST_VIDEO_SINK_H__ #include #include /* We just need the public Cogl api for cogl-gst but we first need to * undef COGL_COMPILATION to avoid getting an error that normally * checks cogl.h isn't used internally. */ #ifdef COGL_COMPILATION #undef COGL_COMPILATION #endif #include #include /** * SECTION:cogl-gst-video-sink * @short_description: A video sink for integrating a GStreamer * pipeline with a Cogl pipeline. * * #CoglGstVideoSink 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 cogl_gst_video_sink_new(). The * application can then listen for the #CoglGstVideoSink::new-frame * signal which will be emitted whenever there are new textures ready * for rendering. For simple rendering, the application can just call * cogl_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 * #CoglGstVideoSink::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 cogl_gst_video_sink_get_pipeline() or it can * create its own pipeline from scratch and ask the sink to configure * it with cogl_gst_video_sink_setup_pipeline(). If a custom pipeline * is created using one of these methods then the application should * call cogl_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 cogl_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. * * Since: 1.16 */ G_BEGIN_DECLS #define COGL_GST_TYPE_VIDEO_SINK cogl_gst_video_sink_get_type() #define COGL_GST_VIDEO_SINK(obj) \ (G_TYPE_CHECK_INSTANCE_CAST ((obj), \ COGL_GST_TYPE_VIDEO_SINK, CoglGstVideoSink)) #define COGL_GST_VIDEO_SINK_CLASS(klass) \ (G_TYPE_CHECK_CLASS_CAST ((klass), \ COGL_GST_TYPE_VIDEO_SINK, CoglGstVideoSinkClass)) #define COGL_GST_IS_VIDEO_SINK(obj) \ (G_TYPE_CHECK_INSTANCE_TYPE ((obj), \ COGL_GST_TYPE_VIDEO_SINK)) #define COGL_GST_IS_VIDEO_SINK_CLASS(klass) \ (G_TYPE_CHECK_CLASS_TYPE ((klass), \ COGL_GST_TYPE_VIDEO_SINK)) #define COGL_GST_VIDEO_SINK_GET_CLASS(obj) \ (G_TYPE_INSTANCE_GET_CLASS ((obj), \ COGL_GST_TYPE_VIDEO_SINK, CoglGstVideoSinkClass)) typedef struct _CoglGstVideoSink CoglGstVideoSink; typedef struct _CoglGstVideoSinkClass CoglGstVideoSinkClass; typedef struct _CoglGstVideoSinkPrivate CoglGstVideoSinkPrivate; /** * CoglGstVideoSink: * * The #CoglGstVideoSink structure contains only private data and * should be accessed using the provided API. * * Since: 1.16 */ struct _CoglGstVideoSink { /*< private >*/ GstBaseSink parent; CoglGstVideoSinkPrivate *priv; }; /** * CoglGstVideoSinkClass: * @new_frame: handler for the #CoglGstVideoSink::new-frame signal * @pipeline_ready: handler for the #CoglGstVideoSink::pipeline-ready signal * * Since: 1.16 */ /** * CoglGstVideoSink::new-frame: * @sink: the #CoglGstVideoSink * * 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 cogl_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 * cogl_gst_video_sink_attach_frame() to attach the textures. * * Since: 1.16 */ /** * CoglGstVideoSink::pipeline-ready: * @sink: the #CoglGstVideoSink * * 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 * cogl_gst_video_sink_get_pipeline() or it can be a completely custom * pipeline which is setup using cogl_gst_video_sink_setup_pipeline(). * * Note that it is an error to call either of those functions before * this signal is emitted. The #CoglGstVideoSink::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. * * Since: 1.16 */ struct _CoglGstVideoSinkClass { /*< private >*/ GstBaseSinkClass parent_class; /*< public >*/ void (* new_frame) (CoglGstVideoSink *sink); void (* pipeline_ready) (CoglGstVideoSink *sink); /*< private >*/ void *_padding_dummy[8]; }; GType cogl_gst_video_sink_get_type (void) G_GNUC_CONST; /** * cogl_gst_video_sink_new: * @ctx: The #CoglContext * * Creates a new #CoglGstVideoSink which will create resources for use * with the given context. * * Return value: (transfer full): a new #CoglGstVideoSink * Since: 1.16 */ CoglGstVideoSink * cogl_gst_video_sink_new (CoglContext *ctx); /** * cogl_gst_video_sink_is_ready: * @sink: The #CoglGstVideoSink * * Returns whether the pipeline is ready and so * cogl_gst_video_sink_get_pipeline() and * cogl_gst_video_sink_setup_pipeline() can be called without causing error. * * Note: Normally an application will wait until the * #CoglGstVideoSink::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. * * Return value: %TRUE if the sink is ready, else %FALSE * Since: 1.16 */ CoglBool cogl_gst_video_sink_is_ready (CoglGstVideoSink *sink); /** * cogl_gst_video_sink_get_pipeline: * @vt: The #CoglGstVideoSink * * 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 * #CoglGstVideoSink::pipeline-ready signal is emitted. * * Return value: (transfer none): the pipeline for rendering the * current frame * Since: 1.16 */ CoglPipeline * cogl_gst_video_sink_get_pipeline (CoglGstVideoSink *vt); /** * cogl_gst_video_sink_set_context: * @vt: The #CoglGstVideoSink * @ctx: The #CoglContext for the sink to use * * Sets the #CoglContext that the video sink should use for creating * any resources. This function would normally only be used if the * sink was constructed via gst_element_factory_make() instead of * cogl_gst_video_sink_new(). * * Since: 1.16 */ void cogl_gst_video_sink_set_context (CoglGstVideoSink *vt, CoglContext *ctx); /** * cogl_gst_video_sink_get_free_layer: * @sink: The #CoglGstVideoSink * * This can be used when doing specialised rendering of the video by * customizing the pipeline. #CoglGstVideoSink may use up to three * private layers on the pipeline in order to attach the textures of * the video frame. This function will return the index of the next * available unused layer after the sink's internal layers. This can * be used by the application to add additional layers, for example to * blend in another color in the fragment processing. * * Return value: the index of the next available layer after the * sink's internal layers. * Since: 1.16 */ int cogl_gst_video_sink_get_free_layer (CoglGstVideoSink *sink); /** * cogl_gst_video_sink_attach_frame: * @sink: The #CoglGstVideoSink * @pln: A #CoglPipeline * * Updates the given pipeline with the textures for the current frame. * This can be used if the application wants to customize the * rendering using its own pipeline. Typically this would be called in * response to the #CoglGstVideoSink::new-frame signal which is * emitted whenever the new textures are available. The application * would then make a copy of its template pipeline and call this to * set the textures. * * Since: 1.16 */ void cogl_gst_video_sink_attach_frame (CoglGstVideoSink *sink, CoglPipeline *pln); /** * cogl_gst_video_sink_set_first_layer: * @sink: The #CoglGstVideoSink * @first_layer: The new first layer * * Sets the index of the first layer that the sink will use for its * rendering. This is useful if the application wants to have custom * layers that appear before the layers added by the sink. In that * case by default the sink's layers will be modulated with the result * of the application's layers that come before @first_layer. * * Note that if this function is called then the name of the function * to call in the shader snippets to sample the video will also * change. For example, if @first_layer is three then the function * will be cogl_gst_sample_video3. * * Since: 1.16 */ void cogl_gst_video_sink_set_first_layer (CoglGstVideoSink *sink, int first_layer); /** * cogl_gst_video_sink_set_default_sample: * @sink: The #CoglGstVideoSink * @default_sample: Whether to add the default sampling * * By default the pipeline generated by * cogl_gst_video_sink_setup_pipeline() and * cogl_gst_video_sink_get_pipeline() will have a layer with a shader * snippet that automatically samples the video. If the application * wants to sample the video in a completely custom way using its own * shader snippet it can set @default_sample to %FALSE to avoid this * default snippet being added. In that case the application's snippet * can call cogl_gst_sample_video0 to sample the texture itself. * * Since: 1.16 */ void cogl_gst_video_sink_set_default_sample (CoglGstVideoSink *sink, CoglBool default_sample); /** * cogl_gst_video_sink_setup_pipeline: * @sink: The #CoglGstVideoSink * @pipeline: A #CoglPipeline * * 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 * #CoglGstVideoSink::pipeline-ready signal. * * Note: it is considered an error to call this function before the * #CoglGstVideoSink::pipeline-ready signal is emitted. * * Since: 1.16 */ void cogl_gst_video_sink_setup_pipeline (CoglGstVideoSink *sink, CoglPipeline *pipeline); /** * cogl_gst_video_sink_get_aspect: * @sink: A #CoglGstVideoSink * * Returns a width-for-height aspect ratio that lets you calculate a * suitable width for displaying your video based on a given height by * multiplying your chosen height by the returned aspect ratio. * * This aspect ratio is calculated based on the underlying size of the * video buffers and the current pixel-aspect-ratio. * * Return value: a width-for-height aspect ratio * * Since: 1.16 * Stability: unstable */ float cogl_gst_video_sink_get_aspect (CoglGstVideoSink *sink); /** * cogl_gst_video_sink_get_width_for_height: * @sink: A #CoglGstVideoSink * @height: A specific output @height * * Calculates a suitable output width for a specific output @height * that will maintain the video's aspect ratio. * * Return value: An output width for the given output @height. * * Since: 1.16 * Stability: unstable */ float cogl_gst_video_sink_get_width_for_height (CoglGstVideoSink *sink, float height); /** * cogl_gst_video_sink_get_height_for_width: * @sink: A #CoglGstVideoSink * @width: A specific output @width * * Calculates a suitable output height for a specific output @width * that will maintain the video's aspect ratio. * * Return value: An output height for the given output @width. * * Since: 1.16 * Stability: unstable */ float cogl_gst_video_sink_get_height_for_width (CoglGstVideoSink *sink, float width); /** * CoglGstRectangle: * @x: The X coordinate of the top left of the rectangle * @y: The Y coordinate of the top left of the rectangle * @width: The width of the rectangle * @height: The height of the rectangle * * Describes a rectangle that can be used for video output. */ typedef struct _CoglGstRectangle { float x; float y; float width; float height; } CoglGstRectangle; /** * cogl_gst_video_sink_fit_size: * @sink: A #CoglGstVideoSink * @available: (in): The space available for video output * @output: (inout): The return location for the calculated output position * * Calculates a suitable @output rectangle that can fit inside the * @available space while maintaining the aspect ratio of the current * video. * * Applications would typically use this api for "letterboxing" by * using this api to position a video inside a fixed screen space and * filling the remaining space with black borders. * * Since: 1.16 * Stability: unstable */ void cogl_gst_video_sink_fit_size (CoglGstVideoSink *sink, const CoglGstRectangle *available, CoglGstRectangle *output); G_END_DECLS #endif