Class: SCC

Inherits:
Object
  • Object
show all
Includes:
AllFather, CommonUtils
Defined in:
lib/scc.rb

Overview

Library to handle SCC Files

Uses the translator available to do the necessary language operations as defined by the AllFather

Constant Summary collapse

SUPPORTED_TRANSFORMATIONS = 
[TYPE_SRT, TYPE_VTT, TYPE_TTML, TYPE_DFXP]

Constants included from CommonUtils

CommonUtils::CREDITS, CommonUtils::SCC_DEFAULT_FRAME_RATE

Constants included from AllFather

AllFather::TYPE_DFXP, AllFather::TYPE_SCC, AllFather::TYPE_SRT, AllFather::TYPE_TTML, AllFather::TYPE_VTT, AllFather::VALID_FILES

Instance Method Summary collapse

Methods included from CommonUtils

#create_file, #extension_from_type, #new_cue, #scc_encode, #time_details, #write_cue

Methods included from AllFather

#callsign

Constructor Details

#initialize(cc_file) ⇒ SCC

Returns a new instance of SCC.



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

def initialize(cc_file)
  @cc_file = cc_file
  raise "Invalid SCC file provided" unless is_valid?
end

Instance Method Details

#infer_languages ⇒ Object 



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# File 'lib/scc.rb', line 37

def infer_languages
  lang = nil
  begin
    sample_text = get_text(@cc_file, 100)
    lang = @translator.infer_language(sample_text)
  rescue StandardError => e
    puts "Error while detecting the language due to #{e.message}"
  end
  [lang]
end

#is_valid? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/scc.rb', line 24

def is_valid?
  # Do any SCC specific validations here
  if @cc_file =~ /^.*\.(scc)$/
    return true
  end
  return false
end

#set_translator(translator) ⇒ Object 



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# File 'lib/scc.rb', line 32

def set_translator(translator)
  super(translator)
  @translator = translator
end

#supported_transformations ⇒ Object 



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# File 'lib/scc.rb', line 52

def supported_transformations
  return SUPPORTED_TRANSFORMATIONS
end

#transform_to(types, src_lang, target_lang, output_dir) ⇒ Object 



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# File 'lib/scc.rb', line 56

def transform_to(types, src_lang, target_lang, output_dir)
  # Let's start off with some validations
  super(types, src_lang, target_lang, output_dir)

  # Suffix output dir with File seperator
  output_dir = "#{output_dir}#{File::Separator}" unless output_dir.end_with?(File::Separator)
  
  # Prepare the output files for each type
  file_map = {}
  types.each do |type|
    output_file = File.basename(@cc_file, File.extname(@cc_file)) + extension_from_type(type)
    out_file = "#{output_dir}#{output_file}"
    if create_file(TYPE_SCC, type, out_file, target_lang)
      file_map[type] = out_file
    else
      raise StandardError.new("Failed to create output file for type #{type}")
    end
  end

  # Read the file and prepare the cue model
  prev_cue_info = cur_cue_info = nil
  ccfile = File.open(@cc_file, 'r:UTF-8', &:read)
  cue_index = 1
  ccfile.each_line do | line |
    time_point = line.scan(/(^\d\d:\d\d:\d\d:\d\d\s)(.*)/)
    unless time_point.empty?
      scc_text_code = time_point[0][1].strip
      message = decode(scc_text_code)
      # Replace \u0000 with empty as this causes the ttml / dfxp outputs
      # to treat them as end and terminates the xml the moment this is encountered
      # https://github.com/sparklemotion/nokogiri/issues/1535
      message = message.gsub(/\u0000/, '')
      if prev_cue_info.nil?
        prev_cue_info = CueInfo.new(TYPE_SCC)
        prev_cue_info.index = cue_index
        prev_cue_info.message = message
        prev_cue_info.start = time_point[0][0].strip
      else
        cur_cue_info = CueInfo.new(TYPE_SCC)
        cur_cue_info.index = cue_index
        cur_cue_info.message = message
        cur_cue_info.start = time_point[0][0].strip
        # Set the previous cue info's end time to current cue's start time
        # TODO: Need to see if we need to reduce alteast 1 fps or 1s
        prev_cue_info.end = cur_cue_info.start
        prev_cue_info.start_time_units = time_details(prev_cue_info.start, TYPE_SCC)
        prev_cue_info.end_time_units = time_details(prev_cue_info.end, TYPE_SCC)
        write_cue(prev_cue_info, file_map)
        prev_cue_info = cur_cue_info
      end
      cue_index += 1
    end
  end
  # we need to set some end time, but don't know the same !!
  # for now setting the start time itself
  cur_cue_info.end = cur_cue_info.start 
  cur_cue_info.start_time_units = time_details(cur_cue_info.start, TYPE_SCC)
  cur_cue_info.end_time_units = time_details(cur_cue_info.end, TYPE_SCC)
  write_cue(cur_cue_info, file_map, true)
end

#translate(src_lang, dest_lang, out_file) ⇒ Object 



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# File 'lib/scc.rb', line 48

def translate(src_lang, dest_lang, out_file)
  raise "Not Implemented. Class #{self.class.name} doesn't implement translate yet !!"
end