Class: Scissor::Writer

Inherits:
Object
  • Object
show all
Includes:
Loggable
Defined in:
lib/scissor/writer.rb

Defined Under Namespace

Classes: CommandFailed, CommandNotFound, EmptyFragment, Error, FileExists

Instance Method Summary collapse

Methods included from Loggable

#logger

Constructor Details

#initialize ⇒ Writer

Returns a new instance of Writer.



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# File 'lib/scissor/writer.rb', line 17

def initialize
  @tracks = []

  which('ecasound')
  which('rubberband')
end

Instance Method Details

#add_track(fragments) ⇒ Object 



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# File 'lib/scissor/writer.rb', line 24

def add_track(fragments)
  @tracks << fragments
end

#join_fragments(fragments, outfile, tmpdir) ⇒ Object 



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# File 'lib/scissor/writer.rb', line 28

def join_fragments(fragments, outfile, tmpdir)
  position = 0.0
  cmd = %w/ecasound/
  is_mono = {}

  fragments.each_with_index do |fragment, index|
    fragment_filename = fragment.filename

    is_mono[fragment_filename] ||= mono?(fragment_filename)

    if !index.zero? && (index % 28).zero?
      run_command(cmd.join(' '))
      cmd = %w/ecasound/
    end

    fragment_outfile = tmpdir + (Digest::MD5.hexdigest(fragment_filename.to_s) + '.wav')

    unless fragment_outfile.exist?
      movie = FFMPEG::Movie.new(fragment_filename.to_s)
      movie.transcode(fragment_outfile.to_s, :audio_sample_rate => 44100)
    end

    cmd << "-a:#{index} -o:#{outfile} -y:#{position}#{is_mono[fragment_filename] ? ' -chcopy:1,2' : ''}"

    if fragment.pan != 50
      cmd << "-epp:%i" % fragment.pan
    end

    if fragment.stretched? && fragment.pitch.to_f != 100.0
      rubberband_out = tmpdir + (Digest::MD5.hexdigest(fragment_filename.to_s) + "rubberband_#{index}.wav")
      rubberband_temp = tmpdir + "_rubberband.wav"

      run_command("ecasound " +
        "-i:" +
        (fragment.reversed? ? 'reverse,' : '') +
        "select,#{fragment.start},#{fragment.original_duration},\"#{fragment_outfile}\" -o:#{rubberband_temp} "
      )
      run_command("rubberband -T #{fragment.pitch.to_f/100} \"#{rubberband_temp}\" \"#{rubberband_out}\"")

      cmd << "-i:\"#{rubberband_out}\""
    else
      cmd <<
        "-i:" +
        (fragment.reversed? ? 'reverse,' : '') +
        "select,#{fragment.start},#{fragment.original_duration},\"#{fragment_outfile}\" " +
        (fragment.pitch.to_f == 100.0 ? "" : "-ei:#{fragment.pitch} ")
    end

    position += fragment.duration
  end

  run_command(cmd.join(' '))
end

#mix_files(filenames, outfile) ⇒ Object 



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# File 'lib/scissor/writer.rb', line 82

def mix_files(filenames, outfile)
  cmd = %w/ecasound/

  filenames.each_with_index do |tf, index|
    cmd << "-a:#{index} -i:#{tf}"
  end

  cmd << "-a:all -o:#{outfile}"
  run_command(cmd.join(' '))
end

#run_command(cmd) ⇒ Object 



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# File 'lib/scissor/writer.rb', line 137

def run_command(cmd)
  logger.debug("run_command: #{cmd}")

  result, error = '', ''

  begin
    status = Open4.spawn cmd, 'stdout' => result, 'stderr' => error
  rescue Open4::SpawnError => e
    raise CommandFailed.new(e.cmd)
  ensure
    logger.debug(result)
    logger.debug(error)
  end

  if status && status.exitstatus != 0
    raise CommandFailed.new(cmd)
  end

  return result
end

#to_file(filename, options) ⇒ Object 



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# File 'lib/scissor/writer.rb', line 93

def to_file(filename, options)
  filename = Pathname.new(filename)
  full_filename = filename.expand_path

  if @tracks.flatten.empty?
    raise EmptyFragment
  end

  options = {
    :overwrite => false,
    :bitrate => '128k'
  }.merge(options)

  if filename.exist?
    if options[:overwrite]
      filename.unlink
    else
      raise FileExists
    end
  end

  TempDir.create do |dir|
    tmpdir = Pathname.new(dir)
    tmpfiles = []

    @tracks.each_with_index do |fragments, track_index|
      tmpfile = tmpdir + 'track_%s.wav' % track_index.to_s
      tmpfiles << tmpfile
      join_fragments(fragments, tmpfile, tmpdir)
    end

    mix_files(tmpfiles, final_tmpfile = tmpdir + 'tmp.wav')

    movie = FFMPEG::Movie.new(final_tmpfile.to_s)
    movie.transcode(full_filename.to_s, :audio_sample_rate => 44100, :audio_bitrate => options[:bitrate])
  end
end

#which(command) ⇒ Object 



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# File 'lib/scissor/writer.rb', line 131

def which(command)
  run_command("which #{command}")
rescue
  raise CommandNotFound.new(command + ': command not found')
end