smptealpha
smptealpha can accept an I420 or AYUV video stream. An alpha channel is added using an effect specific SMPTE mask in the I420 input case. In the AYUV case, the alpha channel is modified using the effect specific SMPTE mask.
The position property is a controllabe double between 0.0 and 1.0 that specifies the position in the transition. 0.0 is the start of the transition with the alpha channel to complete opaque where 1.0 has the alpha channel set to completely transparent.
The depth property defines the precision in bits of the mask. A higher presision will create a mask with smoother gradients in order to avoid banding.
Sample pipelines
Here is a pipeline to demonstrate the smpte transition :
 gst-launch-1.0 -v videotestsrc ! smptealpha border=20000 type=44
 position=0.5 ! videomixer ! videoconvert ! ximagesink
This shows a midway bowtie-h transition a from a videotestsrc to a transparent image. The edges of the transition are smoothed with a 20000 big border.
Hierarchy
GObject ╰──GInitiallyUnowned ╰──GstObject ╰──GstElement ╰──GstBaseTransform ╰──GstVideoFilter ╰──smptealpha
Factory details
Authors: – Wim Taymans 
Classification: – Filter/Editor/Video
Rank – none
Plugin – smpte
Package – GStreamer Good Plug-ins
Pad Templates
sink
        video/x-raw:
         format: I420
          width: [ 1, 2147483647 ]
         height: [ 1, 2147483647 ]
      framerate: [ 0/1, 2147483647/1 ]
video/x-raw:
         format: YV12
          width: [ 1, 2147483647 ]
         height: [ 1, 2147483647 ]
      framerate: [ 0/1, 2147483647/1 ]
video/x-raw:
         format: AYUV
          width: [ 1, 2147483647 ]
         height: [ 1, 2147483647 ]
      framerate: [ 0/1, 2147483647/1 ]
video/x-raw:
         format: ARGB
          width: [ 1, 2147483647 ]
         height: [ 1, 2147483647 ]
      framerate: [ 0/1, 2147483647/1 ]
video/x-raw:
         format: BGRA
          width: [ 1, 2147483647 ]
         height: [ 1, 2147483647 ]
      framerate: [ 0/1, 2147483647/1 ]
video/x-raw:
         format: RGBA
          width: [ 1, 2147483647 ]
         height: [ 1, 2147483647 ]
      framerate: [ 0/1, 2147483647/1 ]
video/x-raw:
         format: ARGB
          width: [ 1, 2147483647 ]
         height: [ 1, 2147483647 ]
      framerate: [ 0/1, 2147483647/1 ]
src
        video/x-raw:
         format: AYUV
          width: [ 1, 2147483647 ]
         height: [ 1, 2147483647 ]
      framerate: [ 0/1, 2147483647/1 ]
video/x-raw:
         format: ARGB
          width: [ 1, 2147483647 ]
         height: [ 1, 2147483647 ]
      framerate: [ 0/1, 2147483647/1 ]
video/x-raw:
         format: BGRA
          width: [ 1, 2147483647 ]
         height: [ 1, 2147483647 ]
      framerate: [ 0/1, 2147483647/1 ]
video/x-raw:
         format: RGBA
          width: [ 1, 2147483647 ]
         height: [ 1, 2147483647 ]
      framerate: [ 0/1, 2147483647/1 ]
video/x-raw:
         format: ARGB
          width: [ 1, 2147483647 ]
         height: [ 1, 2147483647 ]
      framerate: [ 0/1, 2147483647/1 ]
Properties
invert
“invert” gboolean
Set to TRUE to invert the transition mask (ie. flip it horizontally).
Flags : Read / Write
Default value : false
position
“position” gdouble
Position of the transition effect
Flags : Read / Write
Default value : 0
type
“type” Smptealpha-transition-type *
The type of transition to use
Flags : Read / Write
Default value : bar-wipe-lr (1)
Named constants
Smptealpha-transition-type
Members
bar-wipe-lr (1) – A bar moves from left to right
        bar-wipe-tb (2) – A bar moves from top to bottom
        box-wipe-tl (3) – A box expands from the upper-left corner to the lower-right corner
        box-wipe-tr (4) – A box expands from the upper-right corner to the lower-left corner
        box-wipe-br (5) – A box expands from the lower-right corner to the upper-left corner
        box-wipe-bl (6) – A box expands from the lower-left corner to the upper-right corner
        four-box-wipe-ci (7) – A box shape expands from each of the four corners toward the center
        four-box-wipe-co (8) – A box shape expands from the center of each quadrant toward the corners of each quadrant
        barndoor-v (21) – A central, vertical line splits and expands toward the left and right edges
        barndoor-h (22) – A central, horizontal line splits and expands toward the top and bottom edges
        box-wipe-tc (23) – A box expands from the top edge's midpoint to the bottom corners
        box-wipe-rc (24) – A box expands from the right edge's midpoint to the left corners
        box-wipe-bc (25) – A box expands from the bottom edge's midpoint to the top corners
        box-wipe-lc (26) – A box expands from the left edge's midpoint to the right corners
        diagonal-tl (41) – A diagonal line moves from the upper-left corner to the lower-right corner
        diagonal-tr (42) – A diagonal line moves from the upper right corner to the lower-left corner
        bowtie-v (43) – Two wedge shapes slide in from the top and bottom edges toward the center
        bowtie-h (44) – Two wedge shapes slide in from the left and right edges toward the center
        barndoor-dbl (45) – A diagonal line from the lower-left to upper-right corners splits and expands toward the opposite corners
        barndoor-dtl (46) – A diagonal line from upper-left to lower-right corners splits and expands toward the opposite corners
        misc-diagonal-dbd (47) – Four wedge shapes split from the center and retract toward the four edges
        misc-diagonal-dd (48) – A diamond connecting the four edge midpoints simultaneously contracts toward the center and expands toward the edges
        vee-d (61) – A wedge shape moves from top to bottom
        vee-l (62) – A wedge shape moves from right to left
        vee-u (63) – A wedge shape moves from bottom to top
        vee-r (64) – A wedge shape moves from left to right
        barnvee-d (65) – A 'V' shape extending from the bottom edge's midpoint to the opposite corners contracts toward the center and expands toward the edges
        barnvee-l (66) – A 'V' shape extending from the left edge's midpoint to the opposite corners contracts toward the center and expands toward the edges
        barnvee-u (67) – A 'V' shape extending from the top edge's midpoint to the opposite corners contracts toward the center and expands toward the edges
        barnvee-r (68) – A 'V' shape extending from the right edge's midpoint to the opposite corners contracts toward the center and expands toward the edges
        iris-rect (101) – A rectangle expands from the center.
        clock-cw12 (201) – A radial hand sweeps clockwise from the twelve o'clock position
        clock-cw3 (202) – A radial hand sweeps clockwise from the three o'clock position
        clock-cw6 (203) – A radial hand sweeps clockwise from the six o'clock position
        clock-cw9 (204) – A radial hand sweeps clockwise from the nine o'clock position
        pinwheel-tbv (205) – Two radial hands sweep clockwise from the twelve and six o'clock positions
        pinwheel-tbh (206) – Two radial hands sweep clockwise from the nine and three o'clock positions
        pinwheel-fb (207) – Four radial hands sweep clockwise
        fan-ct (211) – A fan unfolds from the top edge, the fan axis at the center
        fan-cr (212) – A fan unfolds from the right edge, the fan axis at the center
        doublefan-fov (213) – Two fans, their axes at the center, unfold from the top and bottom
        doublefan-foh (214) – Two fans, their axes at the center, unfold from the left and right
        singlesweep-cwt (221) – A radial hand sweeps clockwise from the top edge's midpoint
        singlesweep-cwr (222) – A radial hand sweeps clockwise from the right edge's midpoint
        singlesweep-cwb (223) – A radial hand sweeps clockwise from the bottom edge's midpoint
        singlesweep-cwl (224) – A radial hand sweeps clockwise from the left edge's midpoint
        doublesweep-pv (225) – Two radial hands sweep clockwise and counter-clockwise from the top and bottom edges' midpoints
        doublesweep-pd (226) – Two radial hands sweep clockwise and counter-clockwise from the left and right edges' midpoints
        doublesweep-ov (227) – Two radial hands attached at the top and bottom edges' midpoints sweep from right to left
        doublesweep-oh (228) – Two radial hands attached at the left and right edges' midpoints sweep from top to bottom
        fan-t (231) – A fan unfolds from the bottom, the fan axis at the top edge's midpoint
        fan-r (232) – A fan unfolds from the left, the fan axis at the right edge's midpoint
        fan-b (233) – A fan unfolds from the top, the fan axis at the bottom edge's midpoint
        fan-l (234) – A fan unfolds from the right, the fan axis at the left edge's midpoint
        doublefan-fiv (235) – Two fans, their axes at the top and bottom, unfold from the center
        doublefan-fih (236) – Two fans, their axes at the left and right, unfold from the center
        singlesweep-cwtl (241) – A radial hand sweeps clockwise from the upper-left corner
        singlesweep-cwbl (242) – A radial hand sweeps counter-clockwise from the lower-left corner.
        singlesweep-cwbr (243) – A radial hand sweeps clockwise from the lower-right corner
        singlesweep-cwtr (244) – A radial hand sweeps counter-clockwise from the upper-right corner
        doublesweep-pdtl (245) – Two radial hands attached at the upper-left and lower-right corners sweep down and up
        doublesweep-pdbl (246) – Two radial hands attached at the lower-left and upper-right corners sweep down and up
        saloondoor-t (251) – Two radial hands attached at the upper-left and upper-right corners sweep down
        saloondoor-l (252) – Two radial hands attached at the upper-left and lower-left corners sweep to the right
        saloondoor-b (253) – Two radial hands attached at the lower-left and lower-right corners sweep up
        saloondoor-r (254) – Two radial hands attached at the upper-right and lower-right corners sweep to the left
        windshield-r (261) – Two radial hands attached at the midpoints of the top and bottom halves sweep from right to left
        windshield-u (262) – Two radial hands attached at the midpoints of the left and right halves sweep from top to bottom
        windshield-v (263) – Two sets of radial hands attached at the midpoints of the top and bottom halves sweep from top to bottom and bottom to top
        windshield-h (264) – Two sets of radial hands attached at the midpoints of the left and right halves sweep from left to right and right to left
        The results of the search are