Class: Scissor::Writer

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

Defined Under Namespace

Classes: CommandFailed, 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 13

def initialize
  @tracks = []

  which('ecasound')
  which('ffmpeg')
end

Instance Method Details

#add_track(fragments) ⇒ Object 



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# File 'lib/scissor/writer.rb', line 20

def add_track(fragments)
  @tracks << fragments
end

#fragments_to_file(fragments, outfile, tmpdir) ⇒ Object 



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

def fragments_to_file(fragments, outfile, tmpdir)
  position = 0.0
  cmd = %w/ecasound/

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

    if !index.zero? && (index % 80).zero?
      run_command(cmd.join(' '))
      cmd = %w/ecasound/
    end

    fragment_outfile =
      fragment_filename.extname.downcase == '.wav' ? fragment_filename :
      tmpdir + (Digest::MD5.hexdigest(fragment_filename) + '.wav')

    unless fragment_outfile.exist?
      run_command("ffmpeg -i \"#{fragment_filename}\" \"#{fragment_outfile}\"")
    end

    cmd <<
      "-a:#{index} " +
      "-i:" +
      (fragment.reversed? ? 'reverse,' : '') +
      "select,#{fragment.start},#{fragment.true_duration},\"#{fragment_outfile}\" " +
      "-o:#{outfile} " +
      (fragment.pitch.to_f == 100.0 ? "" : "-ei:#{fragment.pitch} ") +
      "-y:#{position}"

    position += fragment_duration
  end

  run_command(cmd.join(' '))
end

#mix_files(filenames, outfile) ⇒ Object 



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# File 'lib/scissor/writer.rb', line 60

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 113

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

  result = ''
  status = Open4.popen4(cmd) do |pid, stdin, stdout, stderr|
    logger.debug(stderr.read)
    result = stdout.read
  end

  if 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 71

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

  if @tracks.flatten.empty?
    raise EmptyFragment
  end

  options = {
    :overwrite => false
  }.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|
      tmpfiles << tmpfile = tmpdir + 'track_%s.wav' % track_index.to_s
      fragments_to_file(fragments, tmpfile, tmpdir)
    end

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

    if filename.extname == '.wav'
      File.rename(final_tmpfile, filename)
    else
      run_command("ffmpeg -i \"#{final_tmpfile}\" \"#{filename}\"")
    end
  end
end

#which(command) ⇒ Object 



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# File 'lib/scissor/writer.rb', line 109

def which(command)
  run_command("which #{command}")
end