Class: Pura::Webp::Encoder::BitWriter

Inherits:
Object
  • Object
show all
Defined in:
lib/pura/webp/encoder.rb

Overview

Bit writer (LSB-first, VP8L format)

Instance Method Summary collapse

Constructor Details

#initialize ⇒ BitWriter

Returns a new instance of BitWriter.



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# File 'lib/pura/webp/encoder.rb', line 406

def initialize
  @data = String.new(encoding: Encoding::BINARY)
  @current = 0
  @bits = 0
end

Instance Method Details

#finish ⇒ Object 



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# File 'lib/pura/webp/encoder.rb', line 420

def finish
  @data << (@current & 0xFF).chr if @bits.positive?
  @data
end

#write_bits(value, num_bits) ⇒ Object 



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# File 'lib/pura/webp/encoder.rb', line 412

def write_bits(value, num_bits)
  num_bits.times do |i|
    @current |= ((value >> i) & 1) << @bits
    @bits += 1
    flush_byte if @bits == 8
  end
end