Class: QTRefMovie::QTQuality

Inherits:
QTBase
  • Object
show all
Defined in:
lib/qtrefmovie.rb

Overview

Quality Atom A quality atom describes the relative quality of a movie. This acts as a tie-breaker if more than one movie meets the specified requirements, and it is not otherwise obvious which movie should be played. This would be the case if two qualified movies have the same data rate and CPU speed requirements, for example, or if one movie requires a higher data rate and another requires a higher CPU speed, but both can be played on the current system. In these cases, applications should play the movie with the highest quality, as specified in the quality atom. Only one quality atom is allowed in a given reference movie descriptor atom.

A quality atom may contain the following information.

Size The number of bytes in this quality atom.

Type The type of this atom; this field must be set to ‘rmqu’.

Quality The relative quality of the movie, expressed as a 32-bit integer. A larger number indicates higher quality. A unique value should be given to each movie.

Instance Method Summary collapse

Methods inherited from QTBase

#add_chunk

Constructor Details

#initialize(quality = nil) ⇒ QTQuality

Returns a new instance of QTQuality.



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# File 'lib/qtrefmovie.rb', line 489

def initialize( quality = nil )
  super()
  @type = 'rmqu'
  @flag = 0
  @quality = 500
  set_quality(quality) if quality
end

Instance Method Details

#set_quality(quality) ⇒ Object 



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# File 'lib/qtrefmovie.rb', line 497

def set_quality( quality )
  @quality = quality
end

#size ⇒ Object 



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# File 'lib/qtrefmovie.rb', line 501

def size
  4 * 4
end

#to_s ⇒ Object 



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# File 'lib/qtrefmovie.rb', line 505

def to_s
  str =  [size].pack('N')
  str += @type
  str += [@flag].pack('N')
  str += [@quality].pack('N')
end