Added audio info functionality

app/controllers/media_controller.rb

@@ -1,8 +1,13 @@
 class MediaController < ApplicationController
   include Spectrogram
-  def index
+  def info
     @input_path = './test/fixtures/'
-    @audio = 'TorresianCrow.wav'
+    # not-an-audio-file.wav 
+    # TorresianCrow.wav 
+    # TestAudio1.wv 
+    # sites.yml
+    # this file does not exist.nope
+    @audio = 'TestAudio1.wv'
     @input_audio = @input_path + @audio
     @result = Audio::info(@input_audio)
   end
@@ -16,7 +21,7 @@ def audio
     @input_audio = @input_path + @audio
     @output_audio = @output_path + @modified_audio
 
-    @result = Audio::segment(@input_audio, @output_audio)
+    @result = Audio::modify(@input_audio, @output_audio, [])
   end
   def spectrogram
     @input_path = './test/fixtures/'

app/views/media/info.html.erb

@@ -0,0 +1 @@
+<%= @result %>

lib/modules/OS.rb

@@ -0,0 +1,17 @@
+module OS
+  def OS.windows?
+    (/cygwin|mswin|mingw|bccwin|wince|emx/ =~ RUBY_PLATFORM) != nil
+  end
+
+  def OS.mac?
+   (/darwin/ =~ RUBY_PLATFORM) != nil
+  end
+
+  def OS.unix?
+    !OS.windows?
+  end
+
+  def OS.linux?
+    OS.unix? and not OS.mac?
+  end
+end

lib/modules/audio.rb

@@ -1,33 +1,115 @@
 module Audio
 
+  @ffmpeg_path = "./vendor/bin/ffmpeg/windows/ffmpeg.exe"
+  @ffprobe_path = "./vendor/bin/ffmpeg/windows/ffprobe.exe"
   @sox_path = "./vendor/bin/sox/windows/sox.exe"
+  @wvunpack_path = "./vendor/bin/wavpack/windows/wvunpack.exe"
+  @mp3splt_path = "./vendor/bin/mp3splt/windows/mp3splt.exe"
 
-  @sox_arguments_info = "--info"
   @@my_logger ||= Logger.new("#{Rails.root}/log/my.log")
 
+  # public methods
+  public
+
+  # Provides information about an audio file.
   def self.info(source)
-    # sox command to create a spectrogram from an audio file
-    command = "#{@sox_path} #{@sox_arguments_info} \"#{source}\""
-
-    # run the command and wait for the result
-    stdout_str, stderr_str, status = Open3.capture3(command)
+
+    info = []
+    error = []
 
-    # get the audio file information from the stdout_str
-    something = stdout_str.each_line { |substr| p substr.index(':') }
-
-    # package up all the available information and return it
-    result = [ stdout_str, stderr_str, status, File.exist?(source), something ]
+    sox_info source, info, error
+    ffprobe_info source, info, error
+    wvunpack_info source, info, error
 
+    # return the packaged info array
+    [ info, error ]
   end
-  def self.segment(source, destination)
+
+  # Creates a new audio file from source path in target path, modified according to the
+  # parameters in modify_parameters
+  def self.modify(source, target, modify_parameters)
     # sox command to create a spectrogram from an audio file
-    command = "#{@sox_path} #{@sox_arguments_verbose} \"#{source}\" #{@sox_arguments_output_audio} #{@sox_arguments_sample_rate} #{@sox_arguments_spectrogram} #{@sox_arguments_output} \"#{destination}\""
+    command = "#{@sox_path} #{@sox_arguments_verbose} \"#{source}\" #{@sox_arguments_output_audio} #{@sox_arguments_sample_rate} #{@sox_arguments_spectrogram} #{@sox_arguments_output} \"#{target}\""
 
     # run the command and wait for the result
     stdout_str, stderr_str, status = Open3.capture3(command)
 
     # package up all the available information and return it
-    result = [ stdout_str, stderr_str, status, File.exist?(source), File.exist?(destination) ]
+    result = [ stdout_str, stderr_str, status, File.exist?(source), File.exist?(target) ]
+  end
+
+  # private methods
+  private
+
+  def self.sox_info(source, info, error)
+    sox_arguments_info = "--info"
+    sox_command = "#{@sox_path} #{sox_arguments_info} \"#{source}\"" # commands to get info from audio file
+    sox_stdout_str, sox_stderr_str, sox_status = Open3.capture3(sox_command) # run the commands and wait for the result
+
+    if sox_status.exitstatus == 0
+      # sox std out contains info (separate on first colon(:))
+      sox_stdout_str.strip.split(/\r?\n|\r/).each { |line| info.push [ 'SOX ' + line[0,line.index(':')].strip, line[line.index(':')+1,line.length].strip ] }
+      # sox_stderr_str is empty
+    else
+      error.push ['SOX ERROR',sox_stderr_str]
+    end
+  end
+
+  def self.ffprobe_info(source, info, error)
+    ffprobe_arguments_info = "-sexagesimal -print_format default -show_error -show_streams -show_format"
+    ffprobe_command = "#{@ffprobe_path} #{ffprobe_arguments_info} \"#{source}\""
+    ffprobe_stdout_str, ffprobe_stderr_str, ffprobe_status = Open3.capture3(ffprobe_command)
 
+    if ffprobe_status.exitstatus == 0
+      # ffprobe std out contains info (separate on first equals(=))
+      # ffprobe_stderr_str contains progress info and human-formatted info
+      ffprobe_current_block_name = ''
+      ffprobe_stdout_str.strip.split(/\r?\n|\r/).each do |line| 
+        line.strip!
+        if line[0] == '['
+          # this chomp reverse stuff is due to the lack of a proper 'trim'
+          ffprobe_current_block_name = line.chomp(']').reverse.chomp('[').reverse
+        else
+          current_key = line[0,line.index('=')].strip
+          current_value = line[line.index('=')+1,line.length].strip
+          info.push [ 'FFPROBE ' + ffprobe_current_block_name + ' ' + current_key, current_value ]
+        end
+      end
+    else
+      # ffprobe std err contains info (separate on first equals(=))
+      ffprobe_current_block_name = ''
+      ffprobe_stdout_str.strip.split(/\r?\n|\r/).each do |line| 
+        line.strip!
+        if line[0] == '['
+          # this chomp reverse stuff is due to the lack of a proper 'trim'
+          ffprobe_current_block_name = line.chomp(']').reverse.chomp('[').reverse
+        else
+          current_key = line[0,line.index('=')].strip
+          current_value = line[line.index('=')+1,line.length].strip
+          error.push [ 'FFPROBE ' + ffprobe_current_block_name + ' ' + current_key, current_value ]
+        end
+      end
+    end
   end
+
+  def self.wvunpack_info(source, info, error)
+    wvunpack_arguments_info = "-s"
+    wvunpack_command = "#{@wvunpack_path} #{wvunpack_arguments_info} \"#{source}\"" # commands to get info from audio file
+    wvunpack_stdout_str, wvunpack_stderr_str, wvunpack_status = Open3.capture3(wvunpack_command) # run the commands and wait for the result
+
+    if wvunpack_status.exitstatus == 0
+      # wvunpack std out contains info (separate on first colon(:))
+      wvunpack_stdout_str.strip.split(/\r?\n|\r/).each do |line|
+        line.strip!
+        current_key = line[0,line.index(':')].strip
+        current_value = line[line.index(':')+1,line.length].strip
+        info.push [ 'WVUNPACK ' + current_key, current_value ]
+      end
+
+      # wvunpack_stderr_str contains human-formatted info and errors
+    else
+      info.push [ 'WVUNPACK ERROR', wvunpack_stderr_str.strip!.split(/\r?\n|\r/).last ]
+    end
+  end
+
 end

lib/modules/spectrogram.rb

@@ -1,24 +1,36 @@
+require 'OS'
+
 module Spectrogram
-  @sox_path = "./vendor/bin/sox/windows/sox.exe"
+  @sox_path = if OS.windows? then "./vendor/bin/sox/windows/sox.exe" else "sox" end
   @sox_arguments_verbose = "-V"
   @sox_arguments_output_audio = "-n"
   @sox_arguments_sample_rate = "rate 22050"
   @sox_arguments_spectrogram = "spectrogram -m -r -l -a -q 249 -w hann -y 257 -X 43.06640625 -z 100"
   @sox_arguments_output = "-o"
   @my_logger ||= Logger.new("#{Rails.root}/log/my.log")
-  def self.generate(source, destination)
+
+  # Generate a spectrogram image from an audio file.
+  # The spectrogram will be 257 pixels high, but the length is not known exactly beforehand.
+  # The spectrogram will be created for the entire file. Durations longer than 2 minutes are not recommended.
+  # Source is the audio file, target is the image file that will be created.
+  # An existing image file will not be overwritten.
+  def self.generate(source, target)
+
+    # check for existing image, and do not overwrite
+    if File.exist?(target)
+      return [ "", "", "", source, File.exist?(source), target, File.exist?(target) ]
+    end
 
     # sox command to create a spectrogram from an audio file
-    command = "#{@sox_path} #{@sox_arguments_verbose} \"#{source}\" #{@sox_arguments_output_audio} #{@sox_arguments_sample_rate} #{@sox_arguments_spectrogram} #{@sox_arguments_output} \"#{destination}\""
+    command = "#{@sox_path} #{@sox_arguments_verbose} \"#{source}\" #{@sox_arguments_output_audio} #{@sox_arguments_sample_rate} #{@sox_arguments_spectrogram} #{@sox_arguments_output} \"#{target}\""
 
     # run the command and wait for the result
     stdout_str, stderr_str, status = Open3.capture3(command)
 
     # log the command
     @my_logger.debug(command)
 
-
     # package up all the available information and return it
-    result = [ stdout_str, stderr_str, status, File.exist?(source), File.exist?(destination) ]
+    result = [ stdout_str, stderr_str, status, source, File.exist?(source), target, File.exist?(target) ]
   end
 end