Class: Hornetseye::V4L2Input

Inherits:
Object
  • Object
show all
Includes:
ReaderConversion
Defined in:
docs/hornetseye-v4l2/lib/hornetseye-v4l2/docs.rb,
docs/hornetseye-v4l2/lib/hornetseye-v4l2/v4l2input.rb

Overview

Class for handling a V4L2-compatible camera

See Also:

Constant Summary collapse

TYPE_INTEGER =

Feature type

nil
TYPE_BOOLEAN =

Feature type

nil
TYPE_MENU =

Feature type

nil
TYPE_BUTTON =

Feature type

nil
TYPE_CTRL_CLASS =

Feature type

nil
FEATURE_BASE =

First feature

nil
FEATURE_USER_BASE =

First custom feature

nil
FEATURE_PRIVATE_BASE =

First standard feature

nil
FEATURE_BRIGHTNESS =

A feature

nil
FEATURE_CONTRAST =

A feature

nil
FEATURE_SATURATION =

A feature

nil
FEATURE_HUE =

A feature

nil
FEATURE_AUDIO_VOLUME =

A feature

nil
FEATURE_AUDIO_BALANCE =

A feature

nil
FEATURE_AUDIO_BASS =

A feature

nil
FEATURE_AUDIO_TREBLE =

A feature

nil
FEATURE_AUDIO_MUTE =

A feature

nil
FEATURE_AUDIO_LOUDNESS =

A feature

nil
FEATURE_BLACK_LEVEL =

A feature

nil
FEATURE_AUTO_WHITE_BALANCE =

A feature

nil
FEATURE_DO_WHITE_BALANCE =

A feature

nil
FEATURE_RED_BALANCE =

A feature

nil
FEATURE_BLUE_BALANCE =

A feature

nil
FEATURE_GAMMA =

A feature

nil
FEATURE_WHITENESS =

A feature

nil
FEATURE_EXPOSURE =

A feature

nil
FEATURE_AUTOGAIN =

A feature

nil
FEATURE_GAIN =

A feature

nil
FEATURE_HFLIP =

A feature

nil
FEATURE_VFLIP =

A feature

nil
FEATURE_HCENTER =

A feature

nil
FEATURE_VCENTER =

A feature

nil
FEATURE_LASTP1 =

A feature

nil

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.new(device = '/dev/video0', channel = 0, &action) ⇒ V4L2Input

Open a camera device for input

The device is opened and a list of supported resolutions is handed back as parameter to the code block. The code block must return the selected mode so that initialisation can be completed. If no block is given, the highest available resolution is selected after giving colour modes preference.

Examples:

Open a camera device

require 'hornetseye_v4l2'
include Hornetseye
camera = V4L2Input.new { |modes| modes.last }

Parameters:

  • device (String) (defaults to: '/dev/video0') —

    The device file name.

  • channel (Integer) (defaults to: 0) —

    Number of the input channel to use.

  • action (Proc) —

    An optional block for selecting the desired video mode.

Returns:

  • (V4L2Input) —

    An object for accessing the camera.



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# File 'docs/hornetseye-v4l2/lib/hornetseye-v4l2/v4l2input.rb', line 45

def new( device = '/dev/video0', channel = 0, &action )
  orig_new device, channel do |modes|
    map = { MODE_UYVY   => UYVY,
            MODE_YUYV   => YUY2,
            MODE_YUV420 => I420,
            MODE_GREY   => UBYTE,
            MODE_Y16    => USINT,
            MODE_RGB24  => UBYTERGB,
            MODE_BGR24  => BGR }
    modes.each do |mode|
      unless map[mode.first]
        warn "Unsupported video mode #{"0x%08x" % mode.first} #{mode[1]}x#{mode[2]}"
      end
    end
    frame_types = modes.collect { |mode| [map[mode.first], *mode[1 .. 2]] }.
      select { |mode| mode.first }
    if action
      desired = action.call frame_types
    else
      preference = [I420, UYVY, YUY2, UBYTERGB, BGR, USINT, UBYTE]
      desired = frame_types.sort_by do |mode|
        [-preference.index(mode.first), mode[1] * mode[2]]
      end.last
      raise "Device does not support a known video mode" unless desired
    end
    mode = map.invert[desired[0]]
    raise "Video mode #{desired.typecode} not supported" unless mode
    [mode, desired[1], desired[2]]
  end
end

.orig_new ⇒ Object 



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# File 'docs/hornetseye-v4l2/lib/hornetseye-v4l2/v4l2input.rb', line 27

alias_method :orig_new, :new

Instance Method Details

#close ⇒ V4L2Input

Close the video device

Returns:



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# File 'docs/hornetseye-v4l2/lib/hornetseye-v4l2/docs.rb', line 436

def close
end

#feature_default_value(id) ⇒ Integer

Get default value of feature

Parameters:

  • id (Integer) —

    Feature identifier.

Returns:

  • (Integer) —

    Default value.



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# File 'docs/hornetseye-v4l2/lib/hornetseye-v4l2/docs.rb', line 532

def feature_default_value( id )
end

#feature_exist?(id) ⇒ Boolean

Check for existence of feature

Parameters:

  • id (Integer) —

    Feature identifier.

Returns:

  • (Boolean) —

    Returns true if this feature is supported.



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# File 'docs/hornetseye-v4l2/lib/hornetseye-v4l2/docs.rb', line 468

def feature_exist?( id )
end

#feature_max(id) ⇒ Integer

Get maximum value of feature

Parameters:

  • id (Integer) —

    Feature identifier.

Returns:

  • (Integer) —

    Maximum value.



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# File 'docs/hornetseye-v4l2/lib/hornetseye-v4l2/docs.rb', line 516

def feature_max( id )
end

#feature_min(id) ⇒ Integer

Get minimum value of feature

Parameters:

  • id (Integer) —

    Feature identifier.

Returns:

  • (Integer) —

    Minimum value.



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# File 'docs/hornetseye-v4l2/lib/hornetseye-v4l2/docs.rb', line 508

def feature_min( id )
end

#feature_name(id) ⇒ String

Get name of feature

Parameters:

  • id (Integer) —

    Feature identifier.

Returns:

  • (String) —

    Name of feature.



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# File 'docs/hornetseye-v4l2/lib/hornetseye-v4l2/docs.rb', line 500

def feature_name( id )
end

#feature_read(id) ⇒ Integer

Get value of feature

Parameters:

  • id (Integer) —

    Feature identifier.

Returns:

  • (Integer) —

    Current value of feature.



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# File 'docs/hornetseye-v4l2/lib/hornetseye-v4l2/docs.rb', line 476

def feature_read( id )
end

#feature_step(id) ⇒ Integer

Get step size of feature

Parameters:

  • id (Integer) —

    Feature identifier.

Returns:

  • (Integer) —

    Step size.



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# File 'docs/hornetseye-v4l2/lib/hornetseye-v4l2/docs.rb', line 524

def feature_step( id )
end

#feature_type(id) ⇒ Integer

Get type of feature

Parameters:

  • id (Integer) —

    Feature identifier.

Returns:

  • (Integer) —

    Type of feature.



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# File 'docs/hornetseye-v4l2/lib/hornetseye-v4l2/docs.rb', line 492

def feature_type( id )
end

#feature_write(id, value) ⇒ Integer

Set value of feature

Parameters:

  • id (Integer) —

    Feature identifier.

Returns:

  • (Integer) —

    Returns value.



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# File 'docs/hornetseye-v4l2/lib/hornetseye-v4l2/docs.rb', line 484

def feature_write( id, value )
end

#height ⇒ Integer

Height of video input

Returns:

  • (Integer) —

    Width of video frames.



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# File 'docs/hornetseye-v4l2/lib/hornetseye-v4l2/docs.rb', line 460

def height
end

#read ⇒ MultiArray, Frame_

Read a video frame

Returns:



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# File 'docs/hornetseye-v4l2/lib/hornetseye-v4l2/docs.rb', line 442

def read
end

#status? ⇒ Boolean

Check whether device is not closed

Returns:

  • (Boolean) —

    Returns true as long as device is open.



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# File 'docs/hornetseye-v4l2/lib/hornetseye-v4l2/docs.rb', line 448

def status?
end

#width ⇒ Integer

Width of video input

Returns:

  • (Integer) —

    Width of video frames.



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# File 'docs/hornetseye-v4l2/lib/hornetseye-v4l2/docs.rb', line 454

def width
end