videomixer: GStreamer Good Plugins 1.0 Plugins Reference Manual

videomixer

Properties

Read / Write

Types and Values

struct	GstVideoMixer2
enum	GstVideoMixer2Background

Object Hierarchy

    GObject
    ╰── GInitiallyUnowned
        ╰── GstObject
            ╰── GstElement
                ╰── GstVideoMixer2

Implemented Interfaces

GstVideoMixer2 implements GstChildProxy.

Description

Videomixer can accept AYUV, ARGB and BGRA video streams. For each of the requested sink pads it will compare the incoming geometry and framerate to define the output parameters. Indeed output video frames will have the geometry of the biggest incoming video stream and the framerate of the fastest incoming one.

Videomixer will do colorspace conversion.

Individual parameters for each input stream can be configured on the GstVideoMixer2Pad.

Sample pipelines

gst-launch-1.0 \
  videotestsrc pattern=1 ! \
  video/x-raw,format=AYUV,framerate=\(fraction\)10/1,width=100,height=100 ! \
  videobox border-alpha=0 top=-70 bottom=-70 right=-220 ! \
  videomixer name=mix sink_0::alpha=0.7 sink_1::alpha=0.5 ! \
  videoconvert ! xvimagesink \
  videotestsrc ! \
  video/x-raw,format=AYUV,framerate=\(fraction\)5/1,width=320,height=240 ! mix.

A pipeline to demonstrate videomixer used together with videobox. This should show a 320x240 pixels video test source with some transparency showing the background checker pattern. Another video test source with just the snow pattern of 100x100 pixels is overlaid on top of the first one on the left vertically centered with a small transparency showing the first video test source behind and the checker pattern under it. Note that the framerate of the output video is 10 frames per second.

gst-launch-1.0 videotestsrc pattern=1 ! \
  video/x-raw, framerate=\(fraction\)10/1, width=100, height=100 ! \
  videomixer name=mix ! videoconvert ! ximagesink \
  videotestsrc !  \
  video/x-raw, framerate=\(fraction\)5/1, width=320, height=240 ! mix.

A pipeline to demostrate bgra mixing. (This does not demonstrate alpha blending).

gst-launch-1.0 videotestsrc pattern=1 ! \
  video/x-raw,format =I420, framerate=\(fraction\)10/1, width=100, height=100 ! \
  videomixer name=mix ! videoconvert ! ximagesink \
  videotestsrc ! \
  video/x-raw,format=I420, framerate=\(fraction\)5/1, width=320, height=240 ! mix.

A pipeline to test I420

gst-launch-1.0 videomixer name=mixer sink_1::alpha=0.5 sink_1::xpos=50 sink_1::ypos=50 ! \
  videoconvert ! ximagesink \
  videotestsrc pattern=snow timestamp-offset=3000000000 ! \
  "video/x-raw,format=AYUV,width=640,height=480,framerate=(fraction)30/1" ! \
  timeoverlay ! queue2 ! mixer. \
  videotestsrc pattern=smpte ! \
  "video/x-raw,format=AYUV,width=800,height=600,framerate=(fraction)10/1" ! \
  timeoverlay ! queue2 ! mixer.

A pipeline to demonstrate synchronized mixing (the second stream starts after 3 seconds)

Synopsis

Element Information

plugin	videomixer
author	Wim Taymans <wim@fluendo.com>, Sebastian Dröge <sebastian.droege@collabora.co.uk>
class	Filter/Editor/Video/Compositor

Element Pads

name	sink_%u
direction	sink
presence	request
details	video/x-raw, format=(string){ AYUV, BGRA, ARGB, RGBA, ABGR, Y444, Y42B, YUY2, UYVY, YVYU, I420, YV12, NV12, NV21, Y41B, RGB, BGR, xRGB, xBGR, RGBx, BGRx }, 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, BGRA, ARGB, RGBA, ABGR, Y444, Y42B, YUY2, UYVY, YVYU, I420, YV12, NV12, NV21, Y41B, RGB, BGR, xRGB, xBGR, RGBx, BGRx }, width=(int)[ 1, 2147483647 ], height=(int)[ 1, 2147483647 ], framerate=(fraction)[ 0/1, 2147483647/1 ]

Functions

Types and Values

struct GstVideoMixer2

struct GstVideoMixer2;

The opaque GstVideoMixer2 structure.

enum GstVideoMixer2Background

The different backgrounds videomixer can blend over.

Members

VIDEO_MIXER2_BACKGROUND_CHECKER	checker pattern background
VIDEO_MIXER2_BACKGROUND_BLACK	solid color black background
VIDEO_MIXER2_BACKGROUND_WHITE	solid color white background
VIDEO_MIXER2_BACKGROUND_TRANSPARENT	background is left transparent and layers are composited using "A OVER B" composition rules. This is only applicable to AYUV and ARGB (and variants) as it preserves the alpha channel and allows for further mixing.

Property Details

The `“background”` property

  “background”               GstVideoMixer2Background

Background type.

Flags: Read / Write

Default value: Checker pattern

videomixer

Properties

Types and Values

Object Hierarchy

Implemented Interfaces

Description

Sample pipelines

Synopsis

Element Information

Element Pads

Functions

Types and Values

struct GstVideoMixer2

enum GstVideoMixer2Background

Members

Property Details

The “background” property

The `“background”` property