Class: RubyAudio::Sound

Inherits:
CSound
  • Object
show all
Defined in:
lib/ruby-audio/sound.rb

Overview

Class Sound wraps libsndfile to provide simple reading and writing for a wide variety of file formats

Reading Example:

RubyAudio::Sound.open('sound.wav') do |snd|
  buf = snd.read(:float, 100)
  puts buf.real_size                         #=> 100
end

Writing Example:

buf = RubyAudio::Buffer.float(1000)
out = nil
['snd1.wav', 'snd2.wav', 'snd3.wav'].each do |file|
  RubyAudio::Sound.open(file) do |snd|
    out = RubyAudio::Sound.open('out.wav', 'w', snd.info.clone) if out.nil?

    while snd.read(buf) != 0
      out.write(buf)
    end
  end
end
out.close if out

Instance Method Summary collapse

Methods inherited from CSound

#<<, #close, #closed?, #info, open, #write

Constructor Details

#initialize(path, mode = 'r', info = nil) ⇒ Sound

Creates a new Sound object for the audio file at the given path. Mode defaults to "r", but valid modes are "r", "w", and "rw".

When creating a new sound, a valid SoundInfo object must be passed in, as libsndfile uses it to determine the output format.

info = RubyAudio::SoundInfo.new :channels => 1, :samplerate => 48000, :format => RubyAudio::FORMAT_WAV|RubyAudio::FORMAT_PCM_16
snd = RubyAudio::Sound.new "new.wav", 'r', info



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# File 'lib/ruby-audio/sound.rb', line 33

def initialize(path, mode='r', info=nil)
  info ||= SoundInfo.new
  super(path, mode, info)
end

Instance Method Details

#read(*args) ⇒ Object

Reads a given number of frames from the sound into a buffer

When given a buffer as the first argument, it reads data into that buffer reading an optional number of frames as the second argument. It returns the number of frames read.

Example:

buf = RubyAudio::Buffer.float(1000)
snd.read(buf)                        #=> 1000
snd.read(buf, 50)                    #=> 50

When given a string or symbol as the first argument, it interprets this as the data type and creates a new buffer of the given size to read the data into. The buffer is correctly initialized with the proper number of channels to hold data from that sound.

Example:

buf = snd.read("int", 1000)



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# File 'lib/ruby-audio/sound.rb', line 69

def read(*args)
  case args[0]
  when Buffer
    buf = args[0]
    size = args[1] || buf.size
    return super(buf, size)
  when Symbol, String
    type = args[0]
    buf = Buffer.new(type, args[1], info.channels)
    super(buf, buf.size)
    return buf
  else
    raise ArgumentError, "invalid arguments"
  end
end

#seek(frames, whence = IO::SEEK_SET) ⇒ Object

Seeks to a given offset anInteger in the sound according to the value of whence:

IO::SEEK_CUR  | Seeks to _frames_ plus current position
--------------+----------------------------------------------------
IO::SEEK_END  | Seeks to _frames_ plus end of stream (you probably
              | want a negative value for _frames_)
--------------+----------------------------------------------------
IO::SEEK_SET  | Seeks to the absolute location given by _frames_



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# File 'lib/ruby-audio/sound.rb', line 47

def seek(frames, whence=IO::SEEK_SET)
  super(frames, whence)
end