Class: ScreenshotGenerator

Inherits:
Object
  • Object
show all
Defined in:
lib/screenshot_generator.rb,
lib/screenshot_generator/version.rb

Constant Summary collapse

VERSION = 
"0.0.2"

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(video, size: '640x400') ⇒ ScreenshotGenerator

Returns a new instance of ScreenshotGenerator.

Raises:

  • (ArgumentError) 


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# File 'lib/screenshot_generator.rb', line 13

def initialize(video, size: '640x400')
  @video = video
  @size = size
  raise ArgumentError, "Video does not exist" unless File.exist? @video
end

Instance Attribute Details

#size ⇒ Object (readonly)

Returns the value of attribute size.



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# File 'lib/screenshot_generator.rb', line 19

def size
  @size
end

#video ⇒ Object (readonly)

Returns the value of attribute video.



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# File 'lib/screenshot_generator.rb', line 19

def video
  @video
end

Class Method Details

.extract_frame(video, *args) ⇒ Object

Helper method for fetching a single frame



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# File 'lib/screenshot_generator.rb', line 5

def self.extract_frame(video, *args)
  new(video).extract_frame(*args)
end

.extract_multi(video, *args) ⇒ Object 



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# File 'lib/screenshot_generator.rb', line 9

def self.extract_multi(video, *args)
  new(video).extract_multi(*args)
end

Instance Method Details

#extract_frame(offset, path) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/screenshot_generator.rb', line 21

def extract_frame(offset, path)
  raise ArgumentError, "File already exists" if File.exist? path
  offset = format_offset(offset)
  ffmpeg(
    "-loglevel", "error",
    "-ss", offset,
    "-i", video,
    "-frames:v", 1,
    "-s", size,
    path
  )
end

#extract_multi(dir, count) ⇒ Object 



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# File 'lib/screenshot_generator.rb', line 35

def extract_multi(dir, count)
  dir = Pathname.new(dir)
  0.upto(count) do |index|
    path = dir + "#{index}.jpg"
    segment_size = length / (count + 2)
    offset = (index + 1) * segment_size
    extract_frame(offset, path)
  end
end

#length ⇒ Object 



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# File 'lib/screenshot_generator.rb', line 45

def length
  @length ||= get_length
end