Videomixer can only accept AYUV 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.

Sample pipelines

Here is a pipeline to demonstrate videomixer used together with videobox :

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

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 overlayed 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.

Element Information

GstVideoMixer

typedef struct _GstVideoMixer GstVideoMixer;

The opaque GstVideoMixer structure.

enum GstVideoMixerBackground

typedef enum
{
  VIDEO_MIXER_BACKGROUND_CHECKER,
  VIDEO_MIXER_BACKGROUND_BLACK,
  VIDEO_MIXER_BACKGROUND_WHITE
}
GstVideoMixerBackground;

The different backgrounds videomixer can blend over.

The "background" property

  "background"               GstVideoMixerBackground  : Read / Write

Background type.

Default value: Checker pattern