class V4L2::Device

• V4L2::Device
• Reference
• Object

Overview

Represents an opened V4L2 device.

Included Modules

• V4L2::IOCTL

Defined in:

Constructors

• .new(fd : Int32)

  Initializes the device with the previously opened file descriptor.

• .open(path) : Device

  Opens the V4L2 device at the given path.

Class Method Summary

• .open(path, &block : Device -> )

  Opens the V4L2 device at the given path, yields it, then closes it.

Instance Method Summary

• #audio : Audio

  Retrieves the current audio input.

• #audio=(new_audio : Audio) : Audio

  Sets the current audio input.

• #capability : Capability

  The capabilities of the V4L2 device.

• #close

  Closes the V4L2 device.

• #closed? : Bool

  Determines whether the V4L2 device is closed.

• #each_audio(&) : self

  Enumerates over each audio input supported by the V4L2 device, yielding each Audio object.

• #each_audio_out(&) : self

  Enumerates over each audio output supported by the V4L2 device, yielding each AudioOut object.

• #each_input(&) : self

  Enumerates over the video inputs, yielding each Input object.

• #each_output(&) : self

  Enumerates over the video outputs supported by the V4L2 device, yielding each Output object.

• #each_standard(&) : self

  Enumerates over the supported video standards for the V4L2 device, yielding each Standard object.

• #fd : Int32

  The underlying file descriptor.

• #finalize

  Ensures the V4L2 device gets closed.

• #frame_buffer : Linux::V4L2FrameBuffer

  Retrieves the current frame buffer.

• #frame_buffer=(new_fb)

  Sets the current frame buffer.

• #frequency(tuner : UInt32)

  Retrieves the current tuner or modulator radio frequency, given the tuner or modulator index number.

• #frequency=(frequency : Frequency)

  Sets the current tuner or modulator frequency.

• #input : Int32

  Queries the video input number.

• #input=(new_input : Int32) : Int32

  Sets the video input number.

• #log_status

  Log driver status information.

• #meta_capture

  The META_CAPTURE stream.

• #meta_output

  The META_OUTPUT stream.

• #modulator(index : UInt32 = 0) : Modulator

  Retrieves the current modulator.

• #modulator=(modulator : Modulator)

  Sets the current modulator.

• #output : LibC::Int

  Queries the current video output number.

• #output=(new_output : Int32)

  Sets the current video output number.

• #overlay=(start_or_stop : Bool) : Bool

  Starts or stops video overlay I/O.

• #priority : Priority

  Queries the access priority of the V4L2 device.

• #priority=(new_priority : Priority) : Priority

  Sets the access priority of the device.

• #query_capability : Capability

  Queries the V4L2 device capabilities.

• #read(buffer : Slice(UInt8)) : Int32

  Reads data directly from the V4L2 device's file descriptor.

• #read_timeout : Time::Span

  Queries the read timeout for the V4L2 device's file descriptor.

• #read_timeout=(new_timeout : Time::Span)

  Sets the read timeout for the V4L2 device's file descriptor.

• #sdr_capture

  The SDR_CAPTURE stream.

• #sdr_output

  The SDR_OUTPUT stream.

• #sliced_vbi_capture

  The SLICED_VBI_CAPTURE stream.

• #sliced_vbi_output

  The SLICED_VBI_OUTPUT stream.

• #standard : StandardID

  Queries the current video standard.

• #standard=(new_std_id : StandardID)

  Sets the current video standard.

• #to_unsafe : Int32

  Returns the underlying file descriptor for the V4L2 device.

• #try_format(new_format : Format) : Bool

  Attempts to change the current format of the V4L2 device, but does not actually change the current format.

• #vbi_capture

  The VBI_CAPTURE stream.

• #vbi_output

  The VBI_OUTPUT stream.

• #video_capture

  The VIDEO_CAPTURE stream.

• #video_capture_mplane

  The VIDEO_CAPTURE_MPLANE stream.

• #video_output

  The VIDEO_OUTPUT stream.

• #video_output_mplane

  The VIDEO_OUTPUT_MPLANE stream.

• #video_output_overlay

  The VIDEO_OUTPUT_OVERLAY stream.

• #video_overlay

  The VIDEO_OVERLAY stream.

• #wait_readable

  Waits for the V4L2 device to indicate data is available for reading.

• #write(buffer : Slice(UInt8))

  Writes data directly to the V4L2 device's file descriptor.

Constructor Detail

V4L2::Device.open("/dev/video0")

Class Method Detail

V4L2::Device.open("/dev/video0") do |video|
  # ...
end

Instance Method Detail