v4l2sink

v4l2sink

Synopsis

struct              GstV4l2Sink;

Object Hierarchy

  GObject
   +----GstObject
         +----GstElement
               +----GstBaseSink
                     +----GstVideoSink
                           +----GstV4l2Sink

Implemented Interfaces

GstV4l2Sink implements GstImplementsInterface, GstColorBalance, GstVideoOrientation and GstPropertyProbe.

Properties

  "device"                   gchar*                : Read / Write
  "device-fd"                gint                  : Read
  "device-name"              gchar*                : Read
  "flags"                    GstV4l2DeviceTypeFlags  : Read
  "overlay-height"           guint                 : Read / Write
  "overlay-left"             gint                  : Read / Write
  "overlay-top"              gint                  : Read / Write
  "overlay-width"            guint                 : Read / Write
  "queue-size"               guint                 : Read / Write
  "brightness"               gint                  : Read / Write
  "contrast"                 gint                  : Read / Write
  "hue"                      gint                  : Read / Write
  "saturation"               gint                  : Read / Write
  "crop-height"              guint                 : Read / Write
  "crop-left"                gint                  : Read / Write
  "crop-top"                 gint                  : Read / Write
  "crop-width"               guint                 : Read / Write
  "min-queued-bufs"          guint                 : Read / Write

Description

v4l2sink can be used to display video to v4l2 devices (screen overlays provided by the graphics hardware, tv-out, etc)

Example launch lines

1
gst-launch videotestsrc ! v4l2sink device=/dev/video1
This pipeline displays a test pattern on /dev/video1
1
gst-launch -v videotestsrc ! navigationtest ! v4l2sink
A pipeline to test navigation events. While moving the mouse pointer over the test signal you will see a black box following the mouse pointer. If you press the mouse button somewhere on the video and release it somewhere else a green box will appear where you pressed the button and a red one where you released it. (The navigationtest element is part of gst-plugins-good.) You can observe here that even if the images are scaled through hardware the pointer coordinates are converted back to the original video frame geometry so that the box can be drawn to the correct position. This also handles borders correctly, limiting coordinates to the image area

Details

struct GstV4l2Sink

struct GstV4l2Sink;

Property Details

The "device" property

  "device"                   gchar*                : Read / Write

Device location.

Default value: "/dev/video1"


The "device-fd" property

  "device-fd"                gint                  : Read

File descriptor of the device.

Allowed values: >= -1

Default value: -1


The "device-name" property

  "device-name"              gchar*                : Read

Name of the device.

Default value: NULL


The "flags" property

  "flags"                    GstV4l2DeviceTypeFlags  : Read

Device type flags.


The "overlay-height" property

  "overlay-height"           guint                 : Read / Write

The height of the video overlay; default is equal to negotiated image height.

Default value: 0


The "overlay-left" property

  "overlay-left"             gint                  : Read / Write

The leftmost (x) coordinate of the video overlay; top left corner of screen is 0,0.

Default value: 0


The "overlay-top" property

  "overlay-top"              gint                  : Read / Write

The topmost (y) coordinate of the video overlay; top left corner of screen is 0,0.

Default value: 0


The "overlay-width" property

  "overlay-width"            guint                 : Read / Write

The width of the video overlay; default is equal to negotiated image width.

Default value: 0


The "queue-size" property

  "queue-size"               guint                 : Read / Write

Number of buffers to be enqueud in the driver in streaming mode.

Allowed values: [1,16]

Default value: 12


The "brightness" property

  "brightness"               gint                  : Read / Write

Picture brightness, or more precisely, the black level.

Default value: 0


The "contrast" property

  "contrast"                 gint                  : Read / Write

Picture contrast or luma gain.

Default value: 0


The "hue" property

  "hue"                      gint                  : Read / Write

Hue or color balance.

Default value: 0


The "saturation" property

  "saturation"               gint                  : Read / Write

Picture color saturation or chroma gain.

Default value: 0


The "crop-height" property

  "crop-height"              guint                 : Read / Write

The height of the video crop; default is equal to negotiated image height.

Default value: 0


The "crop-left" property

  "crop-left"                gint                  : Read / Write

The leftmost (x) coordinate of the video crop; top left corner of image is 0,0.

Default value: 0


The "crop-top" property

  "crop-top"                 gint                  : Read / Write

The topmost (y) coordinate of the video crop; top left corner of image is 0,0.

Default value: 0


The "crop-width" property

  "crop-width"               guint                 : Read / Write

The width of the video crop; default is equal to negotiated image width.

Default value: 0


The "min-queued-bufs" property

  "min-queued-bufs"          guint                 : Read / Write

Minimum number of queued bufs; v4l2sink won't dqbuf if the driver doesn't have more than this number (which normally you shouldn't change).

Allowed values: <= 16

Default value: 1