![]() |
![]() |
![]() |
GStreamer Good Plugins 1.0 Plugins Reference Manual | ![]() |
---|---|---|---|---|
Top | Description | Object Hierarchy | Properties |
GObject +----GInitiallyUnowned +----GstObject +----GstElement +----GstBaseTransform +----GstVideoFilter +----GstAlpha
"alpha" gdouble : Read / Write "angle" gfloat : Read / Write "method" GstAlphaMethod : Read / Write "noise-level" gfloat : Read / Write "target-b" guint : Read / Write "target-g" guint : Read / Write "target-r" guint : Read / Write "black-sensitivity" guint : Read / Write "white-sensitivity" guint : Read / Write "prefer-passthrough" gboolean : Read / Write
The alpha element adds an alpha channel to a video stream. The values of the alpha channel can be either be set to a constant or can be dynamically calculated via chroma keying, e.g. blue can be set as the transparent color.
Sample pipeline:
1 2 3 |
gst-launch-1.0 videotestsrc pattern=smpte75 ! alpha method=green ! \ videomixer name=mixer ! videoconvert ! autovideosink \ videotestsrc pattern=snow ! mixer. |
This pipeline adds a alpha channel to the SMPTE color bars with green as the transparent color and mixes the output with a snow video stream.
plugin |
alpha |
author |
Wim Taymans <wim.taymans@gmail.com> Edward Hervey <edward.hervey@collabora.co.uk> Jan Schmidt <thaytan@noraisin.net> |
class |
Filter/Effect/Video |
name |
sink |
direction |
sink |
presence |
always |
details |
video/x-raw, format=(string){ AYUV, ARGB, BGRA, ABGR, RGBA, Y444, xRGB, BGRx, xBGR, RGBx, RGB, BGR, Y42B, YUY2, YVYU, UYVY, I420, YV12, Y41B }, width=(int)[ 1, 2147483647 ], height=(int)[ 1, 2147483647 ], framerate=(fraction)[ 0/1, 2147483647/1 ] |
name |
src |
direction |
source |
presence |
always |
details |
video/x-raw, format=(string){ AYUV, ARGB, BGRA, ABGR, RGBA, Y444, xRGB, BGRx, xBGR, RGBx, RGB, BGR, Y42B, YUY2, YVYU, UYVY, I420, YV12, Y41B }, width=(int)[ 1, 2147483647 ], height=(int)[ 1, 2147483647 ], framerate=(fraction)[ 0/1, 2147483647/1 ] |
"alpha"
property "alpha" gdouble : Read / Write
The value for the alpha channel.
Allowed values: [0,1]
Default value: 1
"angle"
property "angle" gfloat : Read / Write
Size of the colorcube to change.
Allowed values: [0,90]
Default value: 20
"method"
property"method" GstAlphaMethod : Read / Write
How the alpha channels should be created.
Default value: Set/adjust alpha channel
"noise-level"
property "noise-level" gfloat : Read / Write
Size of noise radius.
Allowed values: [0,64]
Default value: 2
"target-b"
property "target-b" guint : Read / Write
The Blue target.
Allowed values: <= 255
Default value: 0
"target-g"
property "target-g" guint : Read / Write
The Green target.
Allowed values: <= 255
Default value: 255
"target-r"
property "target-r" guint : Read / Write
The Red target.
Allowed values: <= 255
Default value: 0
"black-sensitivity"
property "black-sensitivity" guint : Read / Write
Sensitivity to dark colors.
Allowed values: <= 128
Default value: 100
"white-sensitivity"
property "white-sensitivity" guint : Read / Write
Sensitivity to bright colors.
Allowed values: <= 128
Default value: 100