Class: Sh::TagReader

Inherits:
Object show all
Defined in:
lib/sh_tagreader.rb

Class Method Summary collapse

Class Method Details

.read(path) {|metadata| ... } ⇒ Object

Yields:

  • (metadata) 


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# File 'lib/sh_tagreader.rb', line 7

def self.read path
  # Ensure that the path is absolute
  @path = File.expand_path path
  
  # Use shared-mime-info to determine MIME types if
  # it is available.
  if try_require 'shared-mime-info'
    type = MIME.check(@path)
    @mime = type.to_s if type.media == 'audio'
  else
  	# Attempt to use the `file` command
  	begin
    	type = `file --mime-type -b "#{@path.gsub('"', '\\"')}"`.strip
    	@mime = type if type[0..5] == 'audio/'
    rescue Exception
    	@mime = nil
    end
    
    # As a fallback, guess MIME type from file extension.
  if not @mime or @mime.empty?
  @mime = {
    '.mp3' => 'audio/mpeg',
    '.m4a' => 'audio/mp4',
    '.flac' => 'audio/x-flac',
    '.ogg' => 'audio/ogg',
    '.wav' => 'audio/x-wav',
    '.wma' => 'audio/x-ms-wma'
  }[File.extname(@path)]
end
  end
  
  metadata = {}
			
			# Choose appropriate method for MIME type
  begin
    case @mime
    when 'audio/mpeg'
      metadata = TagReader.read_mp3 path
    when 'audio/mp4'
      metadata = TagReader.read_m4a path
    when 'audio/ogg'
      metadata = TagReader.read_ogg path
    when 'audio/x-flac'
      metadata = TagReader.read_flac path
    when 'audio/x-ms-wma'
      metadata = TagReader.read_wma path
    when 'audio/x-wav'
      metadata = TagReader.read_wave path
    end
  rescue Exception
    Log.warning "Couldn't parse tags for " + path
  end
			
			# Report on our metadata findings
  yield metadata if block_given?
  return metadata
end

.read_flac(path) {|metadata| ... } ⇒ Object

Read metadata from FLAC file

Yields:

  • (metadata) 


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# File 'lib/sh_tagreader.rb', line 153

def self.read_flac path
  metadata = {}
  if try_require 'flacinfo'
    flac = FlacInfo.new(path)
    flac.comment.each do |comment|
      split = comment.split('=')
      key = split.first.downcase
      value = (split[1..-1]).join
      value = nil if value == '' or value.is_binary_data?
      case key
      when 'title'
        metadata[:title] = value.to_u if value
      when 'artist'
        metadata[:artist] = value.to_u if value
      when 'album'
        metadata[:album] = value.to_u if value
      when 'year'
        metadata[:year] = value.to_i
      when 'tracknumber'
        metadata[:track_num] = value.to_i
      end
    end

    #TODO: Support METADATA_BLOCK_PICTURE
  else
    Log.info 'Please install the "flacinfo-rb" gem in order to read FLAC info'
  end
  yield metadata if block_given?
  return metadata
end

.read_m4a(path) {|metadata| ... } ⇒ Object

Read metadata from M4A file

Yields:

  • (metadata) 


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# File 'lib/sh_tagreader.rb', line 95

def self.read_m4a path
  metadata = {}
  if try_require 'mp4info'
    mp4 = MP4Info.open path
    metadata[:title] = mp4.NAM.to_u if mp4.NAM
    metadata[:artist] = mp4.ART.to_u if mp4.ART
    metadata[:album] = mp4.ALB.to_u if mp4.ALB
    metadata[:year] = mp4.DAY.to_i
    metadata[:track_num] = mp4.TRKN.first.to_i
    metadata[:duration] = mp4.SECS
    metadata[:cover_art] = mp4.COVR if mp4.COVR
  else
    Log.info 'Please install the "MP4Info" gem in order to read M4A info'
  end
  yield metadata if block
  return metadata
end

.read_mp3(path) {|metadata| ... } ⇒ Object

Read metadata from MP3 file

Yields:

  • (metadata) 


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# File 'lib/sh_tagreader.rb', line 66

def self.read_mp3 path
  metadata = {}
  if try_require 'mp3info'
    Mp3Info.open path do |mp3|
      t = mp3.tag
      metadata[:title] = t.title.to_u if t.title
      metadata[:artist] = t.artist.to_u if t.artist
      metadata[:album] = t.album.to_u if t.album
      metadata[:year] = t.year.to_i
      metadata[:track_num] = t.tracknum.to_i
      metadata[:duration] = mp3.length

      begin
        if mp3.tag2 and mp3.tag2['APIC']
          a = mp3.tag2['APIC'].last
          a = a[1..-1].sub(/[^\0]*\0/, "")[1..-1].sub(/[^\0]*\0/, "")
          metadata[:cover_art] = a
        end
      rescue
      end
    end
  else
    Log.info 'Please install the "ruby-mp3info" gem in order to read MP3 info'
  end
  yield metadata if block_given?
  return metadata
end

.read_ogg(path) {|metadata| ... } ⇒ Object

Read metadata from Ogg Vorbis file

Yields:

  • (metadata) 


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

def self.read_ogg path
  metadata = {}
  if try_require 'vorbis'
    Vorbis::Info.open path do |info|
      dur = info.duration
      metadata[:duration] = dur if dur and dur > 0

      info.comments.each do |k, vs|
        if vs and vs.any?
          v = vs.first

          case k
          when 'TITLE'
            metadata[:title] = v.to_u
          when 'ARTIST'
            metadata[:artist] = v.to_u
          when 'ALBUM'
            metadata[:album] = v.to_u
          when 'YEAR'
            metadata[:year] = v.to_i
          when 'TRACKNUMBER'
            metadata[:track_num] = v.to_i
          when 'COVERART'
            metadata[:cover_art] = Base64.decode64(v)
          when 'METADATA_BLOCK_PICTURE'
            # TODO: Support this:
            # http://wiki.xiph.org/VorbisComment#METADATA_BLOCK_PICTURE
          end
        end rescue Exception
      end
    end rescue Exception
  else
    Log.info 'Please install the "ruby-ogg" gem in order to read Vorbis info'
  end
  yield metadata if block_given?
  return metadata
end

.read_wave(path) {|metadata| ... } ⇒ Object

Read metadata from Wave file

Yields:

  • (metadata) 


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# File 'lib/sh_tagreader.rb', line 214

def self.read_wave path
  metadata = {}
  if try_require 'waveinfo'
    wave = WaveInfo.new path
    metadata[:duration] = wave.duration
  else
    Log.info 'Please install the "waveinfo" gem in order to read WAV info'
  end
  yield metadata if block_given?
  return metadata
end

.read_wma(path) {|metadata| ... } ⇒ Object

Read metadata from WMA file

Yields:

  • (metadata) 


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# File 'lib/sh_tagreader.rb', line 185

def self.read_wma path
  metadata = {}
  if try_require 'wmainfo'
    wma = WmaInfo.new(path)
    wma.tags.each do |key, value|
      key = key.downcase
      value = nil if value == '' or value.is_binary_data?
      case key
      when 'title'
        metadata[:title] = value.to_u if value
      when 'author'
        metadata[:artist] = value.to_u if value
      when 'albumtitle'
        metadata[:album] = value.to_u if value
      when 'year'
        metadata[:year] = value.to_i
      when 'tracknumber'
        metadata[:track_num] = value.to_i
      end
    end
    metadata[:duration] = wma.info["playtime_seconds"]
  else
    Log.info 'Please install the "wmainfo-rb" gem in order to read WMA info'
  end
  yield metadata if block_given?
  return metadata
end