cairo

(from GStreamer Good Plug-ins git)

Render overlay on a video stream using Cairo

Hierarchy

GObject
    ╰──GInitiallyUnowned
        ╰──GstObject
            ╰──GstElement
                ╰──GstBaseTransform
                    ╰──cairooverlay

Factory details

Authors: – Jon Nordby

Classification: – Filter/Editor/Video

Rank – none

Plugin – libgstcairo.so

Package – GStreamer Good Plug-ins git

Pad Templates

sink

video/x-raw:
         format: { BGRx, BGRA, RGB16 }
          width: [ 1, 2147483647 ]
         height: [ 1, 2147483647 ]
      framerate: [ 0/1, 2147483647/1 ]

Presence – always

Direction – sink

src

video/x-raw:
         format: { BGRx, BGRA, RGB16 }
          width: [ 1, 2147483647 ]
         height: [ 1, 2147483647 ]
      framerate: [ 0/1, 2147483647/1 ]

Presence – always

Direction – src

Signals

caps-changed 

caps_changed_callback (GstElement * overlay,
                       GstCaps * caps,
                       gpointer udata)
def caps_changed_callback (overlay, caps, udata):
    #python callback for the 'caps-changed' signal
function caps_changed_callback(overlay: GstElement * overlay, caps: GstCaps * caps, udata: gpointer udata): {
    // javascript callback for the 'caps-changed' signal
}

This signal is emitted when the caps of the element has changed.

Parameters:

overlay –

Overlay element emitting the signal.

caps –

The GstCaps of the element.

udata –
No description available

draw 

draw_callback (GstElement * overlay,
               CairoContext* cr,
               guint64 timestamp,
               guint64 duration,
               gpointer udata)
def draw_callback (overlay, cr, timestamp, duration, udata):
    #python callback for the 'draw' signal
function draw_callback(overlay: GstElement * overlay, cr: CairoContext* cr, timestamp: guint64 timestamp, duration: guint64 duration, udata: gpointer udata): {
    // javascript callback for the 'draw' signal
}

This signal is emitted when the overlay should be drawn.

Parameters:

overlay –

Overlay element emitting the signal.

cr –

Cairo context to draw to.

timestamp –

Timestamp (see GstClockTime) of the current buffer.

duration –

Duration (see GstClockTime) of the current buffer.

udata –
No description available

Properties

draw-on-transparent-surface 

“draw-on-transparent-surface” gboolean

Let the draw signal work on a transparent surface and blend the results with the video at a later time

Flags : Read / Write

Default value : false

name 

“name” gchararray

The name of the object

Flags : Read / Write / Construct

Default value : NULL

parent 

“parent” GstObject *

The parent of the object

Flags : Read / Write

qos 

“qos” gboolean

Handle Quality-of-Service events

Flags : Read / Write

Default value : false

The results of the search are