Class: HLSManifest

Inherits:
Object
  • Object
show all
Includes:
HLSConstants
Defined in:
lib/hls_manifest.rb

Constant Summary

Constants included from HLSConstants

HLSConstants::EXTINF, HLSConstants::EXTM3U, HLSConstants::EXT_X_ALLOW_CACHE, HLSConstants::EXT_X_CUE_IN, HLSConstants::EXT_X_CUE_OUT, HLSConstants::EXT_X_DISCONTINUITY, HLSConstants::EXT_X_ENDLIST, HLSConstants::EXT_X_FAXS_CM, HLSConstants::EXT_X_KEY, HLSConstants::EXT_X_KEY_ATTRS, HLSConstants::EXT_X_MEDIA, HLSConstants::EXT_X_MEDIA_SEQUENCE, HLSConstants::EXT_X_PLAYLIST_TYPE, HLSConstants::EXT_X_STREAM_INF, HLSConstants::EXT_X_STREAM_INF_ATTRS, HLSConstants::EXT_X_TARGETDURATION, HLSConstants::EXT_X_VERSION, HLSConstants::FIXNUM_MAX, HLSConstants::SUPPORTED_M3U8_VERSIONS

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(content = nil) ⇒ HLSManifest

Returns a new instance of HLSManifest.



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# File 'lib/hls_manifest.rb', line 119

def initialize(content = nil)
  @allow_cache = nil
  @media_sequence = nil
  @playlist_type = nil
  @target_duration = nil
  @version = nil
  @is_live = true
  @line_items = []
  @cue_out_items = []

  parse(content)
end

Instance Attribute Details

#cue_out_items ⇒ Object

Returns the value of attribute cue_out_items.



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# File 'lib/hls_manifest.rb', line 117

def cue_out_items
  @cue_out_items
end

#line_items ⇒ Object

Returns the value of attribute line_items.



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# File 'lib/hls_manifest.rb', line 116

def line_items
  @line_items
end

#media_sequence ⇒ Object

Returns the value of attribute media_sequence.



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# File 'lib/hls_manifest.rb', line 112

def media_sequence
  @media_sequence
end

#playlist_type ⇒ Object

Returns the value of attribute playlist_type.



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# File 'lib/hls_manifest.rb', line 113

def playlist_type
  @playlist_type
end

#target_duration ⇒ Object

Returns the value of attribute target_duration.



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

def target_duration
  @target_duration
end

#version ⇒ Object

Returns the value of attribute version.



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# File 'lib/hls_manifest.rb', line 115

def version
  @version
end

Instance Method Details

#allow_cache? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/hls_manifest.rb', line 248

def allow_cache?
  # Not raising an error here in case the EXT-X-ALLOW-CACHE tag is supported for master-level m3u8s
  @allow_cache.nil? || @allow_cache == "YES"
end

#build ⇒ Object 



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# File 'lib/hls_manifest.rb', line 273

def build
  if is_master?
    return <<-EOT.remove_extra_spaces
      #{EXTM3U}
      #{@line_items.map { |item| item.build }.join("\n")}
    EOT
  else
    return <<-EOT.remove_extra_spaces
      #{EXTM3U}
      #{EXT_X_ALLOW_CACHE + ":" + @allow_cache unless @allow_cache.nil?}
      #{EXT_X_MEDIA_SEQUENCE + ":" + @media_sequence.to_s unless @media_sequence.nil?}
      #{EXT_X_PLAYLIST_TYPE + ":" + @playlist_type unless @playlist_type.nil?}
      #{EXT_X_TARGETDURATION + ":" + @target_duration.to_s unless @target_duration.nil?}
      #{EXT_X_VERSION + ":" + @version.to_s unless @version.nil?}
      #{@line_items.map { |item| item.build }.join("\n")}
      #{EXT_X_ENDLIST unless is_live?}
    EOT
  end
end

#empty? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/hls_manifest.rb', line 244

def empty?
  @line_items.empty?
end

#is_live? ⇒ Boolean

Returns:

  • (Boolean)

Raises:

  • (NoMethodError) 


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# File 'lib/hls_manifest.rb', line 263

def is_live?
  raise NoMethodError, "A master-level manifest cannot access this method" if is_master?
  @is_live
end

#is_master? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/hls_manifest.rb', line 268

def is_master?
  # Note: This currently assumes an empty m3u8 is NOT a master m3u8
  !@line_items.empty? && @line_items[0].instance_of?(HLSPlaylist)
end

#length ⇒ Object 



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# File 'lib/hls_manifest.rb', line 253

def length
  @line_items.length
end

#media_length ⇒ Object

Raises:

  • (NoMethodError) 


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# File 'lib/hls_manifest.rb', line 257

def media_length
  # Note(bz): Should we be raising errors here? I'm not sure what our standard or the Ruby standard is
  raise NoMethodError, "A master-level manifest cannot access this method" if is_master?
  @line_items.inject(0) { |sum, x| sum + x.duration }
end

#parse(content) ⇒ Object 



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

def parse(content)
  return if content.nil? || content.empty?

  last_attributes = []
  last_key = nil
  last_playlist_or_media_segment = nil
  last_unhandled_tags = []
  last_sequence = 0

  # Remove any blank lines (including lines with spaces just to be safe)
  lines = content.split("\n").map(&:strip).reject(&:empty?)

  lines.each do |line|
    if line.start_with?(EXT_X_TARGETDURATION)
      @target_duration = line.split(":").last.to_i
    elsif line.start_with?(EXT_X_MEDIA_SEQUENCE)
      @media_sequence = line.split(":").last.to_i
    elsif line.start_with?(EXT_X_PLAYLIST_TYPE)
      @playlist_type = line.split(":").last
    elsif line.start_with?(EXT_X_ENDLIST)
      @is_live = false
    elsif line.start_with?(EXT_X_ALLOW_CACHE)
      @allow_cache = line.split(":").last
    elsif line.start_with?(EXT_X_VERSION)
      @version = line.split(":").last.to_i
    elsif line.start_with?(EXT_X_STREAM_INF)
      attributes = {}
      parse_csv(line.split(":").last).each do |value|
        attribute = value.split("=")
        attributes[attribute[0].strip.upcase] = attribute[1].strip
      end

      playlist = HLSPlaylist.new
      playlist.bandwidth = attributes[EXT_X_STREAM_INF_ATTRS[:BANDWIDTH]]
      playlist.program_id = attributes[EXT_X_STREAM_INF_ATTRS[:PROGRAM_ID]]
      playlist.codecs = attributes[EXT_X_STREAM_INF_ATTRS[:CODECS]]
      playlist.resolution = attributes[EXT_X_STREAM_INF_ATTRS[:RESOLUTION]]
      playlist.audio = attributes[EXT_X_STREAM_INF_ATTRS[:AUDIO]]
      playlist.video = attributes[EXT_X_STREAM_INF_ATTRS[:VIDEO]]

      playlist.bandwidth = playlist.bandwidth.to_i if playlist.bandwidth
      playlist.program_id = playlist.program_id if playlist.program_id
      playlist.codecs = parse_csv(playlist.codecs) if playlist.codecs

      last_playlist_or_media_segment = playlist
      @line_items.push(playlist)
    elsif line.start_with?(EXTINF)
      attributes = parse_csv(line.split(":").last)

      media_segment = HLSMediaSegment.new
      media_segment.duration = attributes[0].to_f
      media_segment.title = attributes[1]
      media_segment.key = last_key
      media_segment.sequence = last_sequence
      last_sequence += 1
      if last_playlist_or_media_segment && last_playlist_or_media_segment.key = last_key
        media_segment.show_key = false
      end

      last_playlist_or_media_segment = media_segment
      @line_items.push(media_segment)
    elsif line.start_with?(EXT_X_DISCONTINUITY)
      last_attributes.push({ :key => 'discontinuity', :val => true })
    elsif  line.start_with?(EXT_X_CUE_OUT)
      last_attributes.push({ :key => 'is_cue_out', :val => true })
      cue_dur = line.match('DURATION=(\d*)')
      last_attributes.push({ :key => 'cue_out_duration', :val => cue_dur[1].to_i }) if cue_dur
      # may or may not contain a duration.
    elsif line.start_with?(EXT_X_CUE_IN)
      last_attributes.push({ :key => 'is_cue_in', :val => true })
    elsif line.start_with?(EXT_X_KEY)
      attributes = {}
      parse_csv(line.split(":", 2).last).each do |attribute|
        attribute = attribute.split("=")
        attributes[attribute[0].strip.upcase] = attribute[1].strip
      end

      key = HLSKey.new(attributes[EXT_X_KEY_ATTRS[:METHOD]],
                       attributes[EXT_X_KEY_ATTRS[:URI]],
                       attributes[EXT_X_KEY_ATTRS[:IV]])

      key.uri.gsub!("\"", "") if key.uri
      key.iv = key.iv.hex if key.iv
      last_key = key

    elsif line.start_with?("#")
      next if EXTM3U == line
      # Handle other unhandled tags or comments
      # Note: Assume that all unhandled tags belong to the sub playlist or media segment that follow
      # This means that trailing tags are not parsed
      # TODO: Add support for other manifest level tags that don't belong to individual line items
      last_unhandled_tags.push(line)
    else
      # We should be dealing with the location of a sub playlist or a media segment here
      # Note: Assume that a manifest cannot contain a mixture of sub playlists and media segments
      if last_playlist_or_media_segment.instance_of?(HLSMediaSegment)
        last_attributes.each{|x| last_playlist_or_media_segment.send("#{x[:key]}=", x[:val]) }
        @cue_out_items.push(last_playlist_or_media_segment) if last_playlist_or_media_segment.is_cue_out
      end
      last_playlist_or_media_segment.location = line
      last_playlist_or_media_segment.tags = last_unhandled_tags
      last_attributes.clear
      last_unhandled_tags = []
    end
  end
end