dfbvideosink
DfbVideoSink renders video frames using the DirectFB library. Rendering can happen in two different modes :
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Standalone: this mode will take complete control of the monitor forcing DirectFB to fullscreen layout.
This is convenient to test using the gst-launch-1.0 command line tool or other simple applications. It is possible to interrupt playback while being in this mode by pressing the Escape key. This mode handles navigation events for every input device supported by the DirectFB library, it will look for available video modes in the fb.modes file and try to switch the framebuffer video mode to the most suitable one. Depending on hardware acceleration capabilities the element will handle scaling or not.
If no acceleration is available it will do clipping or centering of the video frames respecting the original aspect ratio.
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Embedded: this mode will render video frames in a surface provided by the application developer. This is a more advanced usage of the element and it is required to integrate video playback in existing DirectFB applications.
When using this mode the element just renders to the surface provided by the application, that means it won't handle navigation events and won't resize the surface to fit video frames geometry. Application has to implement the necessary code to grab information about the negotiated geometry and resize there surface accordingly.
For both modes the element implements a buffer pool allocation system to optimize memory allocation time and handle reverse negotiation. Indeed if you insert an element like videoscale in the pipeline the video sink will negotiate with it to try get a scaled video for either the fullscreen layout or the application provided external surface.
Example application
Example pipelines
gst-launch-1.0 -v videotestsrc ! dfbvideosink hue=20000 saturation=40000 brightness=25000
test the colorbalance interface implementation in dfbvideosink
Hierarchy
GObject ╰──GInitiallyUnowned ╰──GstObject ╰──GstElement ╰──GstBaseSink ╰──GstVideoSink ╰──dfbvideosink
Implemented interfaces
Factory details
Authors: – Julien Moutte
Classification: – Sink/Video
Rank – marginal
Plugin – directfb
Package – GStreamer Bad Plug-ins
Pad Templates
sink
video/x-raw:
framerate: [ 0/1, 2147483647/1 ]
width: [ 1, 2147483647 ]
height: [ 1, 2147483647 ]
Properties
blocksize
“blocksize” guint
Size in bytes to pull per buffer (0 = default)
Flags : Read / Write
Default value : 4096
enable-last-sample
“enable-last-sample” gboolean
Enable the last-sample property
Flags : Read / Write
Default value : true
layer-mode
“layer-mode” GstDfbVideoSinkLayerMode *
The cooperative level handling the access permission (set this to 'administrative' when the cursor is required)
Flags : Read / Write
Default value : exclusive (1)
max-bitrate
“max-bitrate” guint64
The maximum bits per second to render (0 = disabled)
Flags : Read / Write
Default value : 0
max-lateness
“max-lateness” gint64
Maximum number of nanoseconds that a buffer can be late before it is dropped (-1 unlimited)
Flags : Read / Write
Default value : 5000000
pixel-aspect-ratio
“pixel-aspect-ratio” gchararray
The pixel aspect ratio of the device
Flags : Read / Write
Default value : NULL
processing-deadline
“processing-deadline” guint64
Maximum processing time for a buffer in nanoseconds
Flags : Read / Write
Default value : 15000000
qos
“qos” gboolean
Generate Quality-of-Service events upstream
Flags : Read / Write
Default value : true
render-delay
“render-delay” guint64
Additional render delay of the sink in nanoseconds
Flags : Read / Write
Default value : 0
show-preroll-frame
“show-preroll-frame” gboolean
Whether to render video frames during preroll
Flags : Read / Write / Construct
Default value : true
stats
“stats” GstStructure *
Sink Statistics
Flags : Read
Default value :
application/x-gst-base-sink-stats, average-rate=(double)0, dropped=(guint64)0, rendered=(guint64)0;throttle-time
“throttle-time” guint64
The time to keep between rendered buffers (0 = disabled)
Flags : Read / Write
Default value : 0
vsync
“vsync” gboolean
Wait for next vertical sync to draw frames
Flags : Read / Write
Default value : true
Named constants
GstDfbVideoSinkLayerMode
Members
none (0) – NONE
exclusive (1) – DLSCL_EXCLUSIVE
administrative (2) – DLSCL_ADMINISTRATIVE
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