Class: M3Uzi

Inherits:
Object
  • Object
show all
Defined in:
lib/m3uzi.rb,
lib/m3uzi/tag.rb,
lib/m3uzi/file.rb,
lib/m3uzi/item.rb,
lib/m3uzi/stream.rb,
lib/m3uzi/comment.rb,
lib/m3uzi/version.rb

Defined Under Namespace

Classes: Comment, File, Item, Stream, Tag

Constant Summary collapse

VERSION = 
'0.5.1'

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ M3Uzi

Returns a new instance of M3Uzi.



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# File 'lib/m3uzi.rb', line 15

def initialize
  @header_tags = {}
  @playlist_items = []
  @final_media_file = true
  @version = 1
  @initial_media_sequence = 0
  @sliding_window_duration = nil
  @removed_file_count = 0
  @playlist_type = :live
end

Instance Attribute Details

#final_media_file ⇒ Object

Returns the value of attribute final_media_file.



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# File 'lib/m3uzi.rb', line 12

def final_media_file
  @final_media_file
end

#header_tags ⇒ Object

Returns the value of attribute header_tags.



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# File 'lib/m3uzi.rb', line 11

def header_tags
  @header_tags
end

#initial_media_sequence ⇒ Object

Returns the value of attribute initial_media_sequence.



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# File 'lib/m3uzi.rb', line 13

def initial_media_sequence
  @initial_media_sequence
end

#playlist_items ⇒ Object

Returns the value of attribute playlist_items.



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# File 'lib/m3uzi.rb', line 11

def playlist_items
  @playlist_items
end

#playlist_type ⇒ Object

Returns the value of attribute playlist_type.



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# File 'lib/m3uzi.rb', line 12

def playlist_type
  @playlist_type
end

#sliding_window_duration ⇒ Object

Returns the value of attribute sliding_window_duration.



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# File 'lib/m3uzi.rb', line 13

def sliding_window_duration
  @sliding_window_duration
end

#version ⇒ Object

Returns the value of attribute version.



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# File 'lib/m3uzi.rb', line 13

def version
  @version
end

Instance Method Details

#add_comment(comment = nil) {|new_comment| ... } ⇒ Object

Comments

Yields:

  • (new_comment) 


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# File 'lib/m3uzi.rb', line 256

def add_comment(comment = nil)
  new_comment = M3Uzi::Comment.new
  new_comment.text = comment
  yield(new_comment) if block_given?
  @playlist_items << new_comment
end

#add_file(path = nil, duration = nil) {|new_file| ... } ⇒ Object

Files

Yields:

  • (new_file) 


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# File 'lib/m3uzi.rb', line 195

def add_file(path = nil, duration = nil)
  new_file = M3Uzi::File.new
  new_file.path = path if path
  new_file.duration = duration if duration
  yield(new_file) if block_given?
  @playlist_items << new_file
  cleanup_sliding_window
end

#add_stream(path = nil, bandwidth = nil) {|new_stream| ... } ⇒ Object

Streams

Yields:

  • (new_stream) 


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# File 'lib/m3uzi.rb', line 213

def add_stream(path = nil, bandwidth = nil)
  new_stream = M3Uzi::Stream.new
  new_stream.path = path
  new_stream.bandwidth = bandwidth
  yield(new_stream) if block_given?
  @playlist_items << new_stream
end

#add_tag(name = nil, value = nil) {|new_tag| ... } ⇒ Object

Tags

Yields:

  • (new_tag) 


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# File 'lib/m3uzi.rb', line 230

def add_tag(name = nil, value = nil)
  new_tag = M3Uzi::Tag.new
  new_tag.name = name
  new_tag.value = value
  yield(new_tag) if block_given?
  @header_tags[new_tag.name] = new_tag
end

#check_version_restrictions ⇒ Object

def <<(comment)

add_comment(comment)

end



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# File 'lib/m3uzi.rb', line 267

def check_version_restrictions
  @version = 1

  #
  # Version 2 Features
  #

  # Check for custom IV
  if valid_items(File).detect { |item| item.encryption_key_url && item.encryption_iv }
    @version = 2 if @version < 2
  end

  # Version 3 Features
  if valid_items(File).detect { |item| item.duration.kind_of?(Float) }
    @version = 3 if @version < 3
  end

  # Version 4 Features
  if valid_items(File).detect { |item| item.byterange }
    @version = 4 if @version < 4
  end
  if valid_items(Tag).detect { |item| ['MEDIA','I-FRAMES-ONLY'].include?(item.name) }
    @version = 4 if @version < 4
  end

  # NOTES
  #   EXT-X-I-FRAME-STREAM-INF is supposed to be ignored by older clients.
  #   AUDIO/VIDEO attributes of X-STREAM-INF are used in conjunction with MEDIA, so it should trigger v4.

  @version
end

#filenames ⇒ Object 



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# File 'lib/m3uzi.rb', line 204

def filenames
  items(File).map { |file| file.path }
end

#generate_byterange_line(file) ⇒ Object 



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# File 'lib/m3uzi.rb', line 167

def generate_byterange_line(file)
  line = nil

  if file.byterange
    if file.byterange_offset && file.byterange_offset != @prev_byterange_endpoint
      offset = file.byterange_offset
    elsif @prev_byterange_endpoint.nil?
      offset = 0
    else
      offset = nil
    end

    line = "#EXT-X-BYTERANGE:#{file.byterange_offset.to_i}"
    line += "@#{offset}" if offset

    @prev_byterange_endpoint = offset + file.byterange
  else
    @prev_byterange_endpoint = nil
  end

  line
end

#generate_encryption_key_line(file) ⇒ Object 



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# File 'lib/m3uzi.rb', line 132

def generate_encryption_key_line(file)
  generate_line = false

  default_iv = @encryption_iv || format_iv(@encryption_sequence)

  if (file.encryption_key_url != :unset) && (file.encryption_key_url != @encryption_key_url)
    @encryption_key_url = file.encryption_key_url
    generate_line = true
  end

  if @encryption_key_url && file.encryption_iv != @encryption_iv
    @encryption_iv = file.encryption_iv
    generate_line = true
  end

  @encryption_sequence += 1

  if generate_line
    if @encryption_key_url.nil?
      "#EXT-X-KEY:METHOD=NONE"
    else
      attrs = ['METHOD=AES-128']
      attrs << 'URI="' + @encryption_key_url.gsub('"','%22').gsub(/[\r\n]/,'').strip + '"'
      attrs << "IV=#{@encryption_iv}" if @encryption_iv
      '#EXT-X-KEY:' + attrs.join(',')
    end
  else
    nil
  end
end

#items(kind) ⇒ Object 



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# File 'lib/m3uzi.rb', line 114

def items(kind)
  @playlist_items.select { |item| item.kind_of?(kind) }
end

#reset_byterange_history ⇒ Object 



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# File 'lib/m3uzi.rb', line 163

def reset_byterange_history
  @prev_byterange_endpoint = nil
end

#reset_encryption_key_history ⇒ Object

Playlist generation helpers.



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# File 'lib/m3uzi.rb', line 126

def reset_encryption_key_history
  @encryption_key_url = nil
  @encryption_iv = nil
  @encryption_sequence = 0
end

#stream_names ⇒ Object 



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# File 'lib/m3uzi.rb', line 221

def stream_names
  items(Stream).map { |stream| stream.path }
end

#valid_items(kind) ⇒ Object 



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# File 'lib/m3uzi.rb', line 118

def valid_items(kind)
  @playlist_items.select { |item| item.kind_of?(kind) && item.valid? }
end

#write(path) ⇒ Object 



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# File 'lib/m3uzi.rb', line 110

def write(path)
  ::File.open(path, "w") { |f| write_to_io(f) }
end

#write_to_io(io_stream) ⇒ Object

For now, reading m3u8 files is not keeping up to date with writing, so we’re disabling it in this version. (Possibly to be re-introduced in the future.)

def self.read(path)

m3u = self.new
lines = ::File.readlines(path)
lines.each_with_index do |line, i|
  case type(line)
  when :tag
    name, value = parse_general_tag(line)
    m3u.add_tag do |tag|
      tag.name = name
      tag.value = value
    end
  when :info
    duration, description = parse_file_tag(line)
    m3u.add_file do |file|
      file.path = lines[i+1].strip
      file.duration = duration
      file.description = description
    end
    m3u.final_media_file = false
  when :stream
    attributes = parse_stream_tag(line)
    m3u.add_stream do |stream|
      stream.path = lines[i+1].strip
      attributes.each_pair do |k,v|
        k = k.to_s.downcase.sub('-','_')
        next unless [:bandwidth, :program_id, :codecs, :resolution].include?(k)
        v = $1 if v.to_s =~ /^"(.*)"$/
        stream.send("#{k}=", v)
      end
    end
  when :final
    m3u.final_media_file = true
  else
    next
  end
end
m3u

end



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# File 'lib/m3uzi.rb', line 74

def write_to_io(io_stream)
  reset_encryption_key_history
  reset_byterange_history

  check_version_restrictions
  io_stream << "#EXTM3U\n"
  io_stream << "#EXT-X-VERSION:#{@version.to_i}\n" if @version > 1
  io_stream << "#EXT-X-PLAYLIST-TYPE:#{@playlist_type.to_s.upcase}\n" if [:event,:vod].include?(@playlist_type)

  if items(File).length > 0
    io_stream << "#EXT-X-MEDIA-SEQUENCE:#{@initial_media_sequence+@removed_file_count}\n" if @playlist_type == :live
    max_duration = valid_items(File).map { |f| f.duration.to_f }.max || 10.0
    io_stream << "#EXT-X-TARGETDURATION:#{max_duration.ceil}\n"
  end

  @header_tags.each do |item|
    io_stream << (item.format + "\n") if item.valid?
  end

  @playlist_items.each do |item|
    next unless item.valid?

    if item.kind_of?(File)
      encryption_key_line = generate_encryption_key_line(item)
      io_stream << (encryption_key_line + "\n") if encryption_key_line

      byterange_line = generate_byterange_line(item)
      io_stream << (byterange_line + "\n") if byterange_line
    end

    io_stream << (item.format + "\n")
  end

  io_stream << "#EXT-X-ENDLIST\n" if items(File).length > 0 && (@final_media_file || @playlist_type == :vod)
end