Class: WahWah::Ogg::FlacTag

Inherits:
Object
  • Object
show all
Includes:
Flac::StreaminfoBlock, VorbisComment
Defined in:
lib/wahwah/ogg/flac_tag.rb

Constant Summary

Constants included from Flac::StreaminfoBlock

Flac::StreaminfoBlock::STREAMINFO_BLOCK_SIZE

Constants included from VorbisComment

VorbisComment::COMMET_FIELD_MAPPING

Instance Method Summary collapse

Methods included from Flac::StreaminfoBlock

#parse_streaminfo_block

Methods included from VorbisComment

#parse_vorbis_comment

Constructor Details

#initialize(identification_packet, comment_packet) ⇒ FlacTag

Returns a new instance of FlacTag.



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# File 'lib/wahwah/ogg/flac_tag.rb', line 11

def initialize(identification_packet, comment_packet)
  # Identification packet structure:
  #
  # The one-byte packet type 0x7F
  # The four-byte ASCII signature "FLAC", i.e. 0x46, 0x4C, 0x41, 0x43
  # A one-byte binary major version number for the mapping, e.g. 0x01 for mapping version 1.0
  # A one-byte binary minor version number for the mapping, e.g. 0x00 for mapping version 1.0
  # A two-byte, big-endian binary number signifying the number of header (non-audio) packets, not including this one.
  # The four-byte ASCII native FLAC signature "fLaC" according to the FLAC format specification
  # The STREAMINFO metadata block for the stream.
  #
  # The first identification packet is followed by one or more header packets.
  # Each such packet will contain a single native FLAC metadata block.
  # The first of these must be a VORBIS_COMMENT block.

  id, streaminfo_block_data = identification_packet.unpack("x9A4A*")

  return unless id == "fLaC"
  streaminfo_block = Flac::Block.new(StringIO.new(streaminfo_block_data))
  vorbis_comment_block = Flac::Block.new(StringIO.new(comment_packet))

  parse_streaminfo_block(streaminfo_block.data)
  parse_vorbis_comment(vorbis_comment_block.data)
end