Package edu.wpi.first.cscore

Class VideoSource

java.lang.Object
edu.wpi.first.cscore.VideoSource
All Implemented Interfaces:
AutoCloseable
Direct Known Subclasses:
ImageSource, VideoCamera
public class VideoSource
extends Object
implements AutoCloseable
A source for video that provides a sequence of frames. Each frame may consist of multiple images (e.g. from a stereo or depth camera); these are called channels.

  • Field Details

  • Constructor Details

    • VideoSource

      protected VideoSource​(int handle)
      Constructs a VideoSource.
      Parameters:
      handle - The video source handle.

  • Method Details

    • getKindFromInt

      public static VideoSource.Kind getKindFromInt​(int kind)
      Convert from the numerical representation of kind to an enum type.
      Parameters:
      kind - The numerical representation of kind
      Returns:
      The kind

    • close

      public void close()
      Specified by:
      close in interface AutoCloseable

    • isValid

      public boolean isValid()
      Returns true if the VideoSource is valid.
      Returns:
      True if the VideoSource is valid.

    • getHandle

      public int getHandle()
      Returns the video source handle.
      Returns:
      The video source handle.

    • equals

      public boolean equals​(Object other)
      Overrides:
      equals in class Object

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object

    • getKind

      public VideoSource.Kind getKind()
      Get the kind of the source.
      Returns:
      The kind of the source.

    • getName

      public String getName()
      Get the name of the source. The name is an arbitrary identifier provided when the source is created, and should be unique.
      Returns:
      The name of the source.

    • getDescription

      public String getDescription()
      Get the source description. This is source-kind specific.
      Returns:
      The source description.

    • getLastFrameTime

      public long getLastFrameTime()
      Get the last time a frame was captured.
      Returns:
      Time in 1 us increments.

    • setConnectionStrategy

      public void setConnectionStrategy​(VideoSource.ConnectionStrategy strategy)
      Sets the connection strategy. By default, the source will automatically connect or disconnect based on whether any sinks are connected.

      This function is non-blocking; look for either a connection open or close event or call isConnected() to determine the connection state.

      Parameters:
      strategy - connection strategy (auto, keep open, or force close)

    • isConnected

      public boolean isConnected()
      Returns true if the source currently connected to whatever is providing the images.
      Returns:
      True if the source currently connected to whatever is providing the images.

    • isEnabled

      public boolean isEnabled()
      Gets source enable status. This is determined with a combination of connection strategy and the number of sinks connected.
      Returns:
      True if enabled, false otherwise.

    • getProperty

      public VideoProperty getProperty​(String name)
      Get a property.
      Parameters:
      name - Property name
      Returns:
      Property contents (of kind Property::kNone if no property with the given name exists)

    • enumerateProperties

      public VideoProperty[] enumerateProperties()
      Enumerate all properties of this source.
      Returns:
      Array of video properties.

    • getVideoMode

      public VideoMode getVideoMode()
      Get the current video mode.
      Returns:
      The current video mode.

    • setVideoMode

      public boolean setVideoMode​(VideoMode mode)
      Set the video mode.
      Parameters:
      mode - Video mode
      Returns:
      True if set successfully.

    • setVideoMode

      public boolean setVideoMode​(PixelFormat pixelFormat, int width, int height, int fps)
      Set the video mode.
      Parameters:
      pixelFormat - desired pixel format
      width - desired width
      height - desired height
      fps - desired FPS
      Returns:
      True if set successfully

    • setPixelFormat

      public boolean setPixelFormat​(PixelFormat pixelFormat)
      Set the pixel format.
      Parameters:
      pixelFormat - desired pixel format
      Returns:
      True if set successfully

    • setResolution

      public boolean setResolution​(int width, int height)
      Set the resolution.
      Parameters:
      width - desired width
      height - desired height
      Returns:
      True if set successfully

    • setFPS

      public boolean setFPS​(int fps)
      Set the frames per second (FPS).
      Parameters:
      fps - desired FPS
      Returns:
      True if set successfully

    • setConfigJson

      public boolean setConfigJson​(String config)
      Set video mode and properties from a JSON configuration string.

      The format of the JSON input is: 

       {
     "pixel format": "MJPEG", "YUYV", etc
     "width": video mode width
     "height": video mode height
     "fps": video mode fps
     "brightness": percentage brightness
     "white balance": "auto", "hold", or value
     "exposure": "auto", "hold", or value
     "properties": [
         {
             "name": property name
             "value": property value
         }
     ]
 }
      Parameters:
      config - configuration
      Returns:
      True if set successfully

    • getConfigJson

      public String getConfigJson()
      Get a JSON configuration string.
      Returns:
      JSON configuration string

    • getActualFPS

      public double getActualFPS()
      Get the actual FPS.

      CameraServerJNI#setTelemetryPeriod() must be called for this to be valid (throws VisionException if telemetry is not enabled).

      Returns:
      Actual FPS averaged over the telemetry period.

    • getActualDataRate

      public double getActualDataRate()
      Get the data rate (in bytes per second).

      CameraServerJNI#setTelemetryPeriod() must be called for this to be valid (throws VisionException if telemetry is not enabled).

      Returns:
      Data rate averaged over the telemetry period.

    • enumerateVideoModes

      public VideoMode[] enumerateVideoModes()
      Enumerate all known video modes for this source.
      Returns:
      Vector of video modes.

    • enumerateSinks

      public VideoSink[] enumerateSinks()
      Enumerate all sinks connected to this source.
      Returns:
      Vector of sinks.

    • enumerateSources

      public static VideoSource[] enumerateSources()
      Enumerate all existing sources.
      Returns:
      Vector of sources.