Media file caching and modification

Added configuration for paths to stored files.
Added routes for media files.
Added logging to audio module and implementation of wavpack (.wv to .wav
with segmenting).

app/controllers/media_controller.rb

@@ -1,5 +1,24 @@
 class MediaController < ApplicationController
-  include Spectrogram
+  include Cache, Spectrogram, Audio
+
+  def index
+    # index page for media files
+    @testing = QubarSite::Application.config.media_file_config
+  end
+
+  def item
+    # page for an individual media file
+    # use params to get query string or parsed route parameters
+
+    # get the path for the file matching the request
+    @file_path = Cache::calculate_target_path(params)
+
+    # see if the requested file exists
+
+    @avail_params = params
+
+  end
+
   def info
     @input_path = './test/fixtures/'
     # not-an-audio-file.wav 
@@ -12,18 +31,22 @@ def info
     @result = Audio::info(@input_audio)
   end
   def audio
+    print params
+
     @input_path = './test/fixtures/'
     @output_path = './public/tests/'
 
-    @audio = 'TorresianCrow.wav'
-    @modified_audio = 'TorresianCrow.wav'
+    @audio = 'TestAudio1.wv'
+    @modified_audio = 'TestAudio1.wav'
 
     @input_audio = @input_path + @audio
     @output_audio = @output_path + @modified_audio
 
-    @result = Audio::modify(@input_audio, @output_audio, [])
+
+    #@result = Audio::modify(@input_audio, @output_audio, [])
   end
   def spectrogram
+    print params
     @input_path = './test/fixtures/'
     @output_path = './public/tests/'
 
@@ -33,6 +56,6 @@ def spectrogram
     @input_audio = @input_path + @audio
     @output_image = @output_path + @image
 
-    @result = Spectrogram::generate(@input_audio, @output_image)
+    #@result = Spectrogram::generate(@input_audio, @output_image)
   end
 end

app/views/media/index.html.erb

@@ -0,0 +1,3 @@
+<h1>Media#index</h1>
+<p>Index page for media controller.</p>
+<p><%= @testing %></p>

app/views/media/item.html.erb

@@ -0,0 +1,4 @@
+<h1>Media#item</h1>
+<p>Individual item page for media controller.</p>
+<p><%= @avail_params %></p>
+<p><%= @file_path %></p>

lib/modules/OS.rb

@@ -1,3 +1,4 @@
+# From http://stackoverflow.com/questions/170956/how-can-i-find-which-operating-system-my-ruby-program-is-running-on
 module OS
   def OS.windows?
     (/cygwin|mswin|mingw|bccwin|wince|emx/ =~ RUBY_PLATFORM) != nil

lib/modules/audio.rb

@@ -1,10 +1,12 @@
+require 'OS'
+
 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"
+  @ffmpeg_path = if OS.windows? then "./vendor/bin/ffmpeg/windows/ffmpeg.exe" else "ffmpeg" end
+  @ffprobe_path = if OS.windows? then "./vendor/bin/ffmpeg/windows/ffprobe.exe" else "ffprobe" end
+  @sox_path = if OS.windows? then "./vendor/bin/sox/windows/sox.exe" else "sox" end
+  @wvunpack_path = if OS.windows? then "./vendor/bin/wavpack/windows/wvunpack.exe" else "wvunpack" end
+  @mp3splt_path = if OS.windows? then "./vendor/bin/mp3splt/windows/mp3splt.exe" else "mp3splt" end
 
   @@my_logger ||= Logger.new("#{Rails.root}/log/my.log")
 
@@ -28,14 +30,7 @@ def self.info(source)
   # 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} \"#{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?(target) ]
+    wvunpack(source, target, modify_parameters)
   end
 
   # private methods
@@ -51,6 +46,7 @@ def self.sox_info(source, info, error)
       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
+      Rails.logger.debug "Sox info error. Return status #{sox_status.exitstatus}. Command: #{sox_command}"
       error.push ['SOX ERROR',sox_stderr_str]
     end
   end
@@ -60,6 +56,8 @@ def self.ffprobe_info(source, info, error)
     ffprobe_command = "#{@ffprobe_path} #{ffprobe_arguments_info} \"#{source}\""
     ffprobe_stdout_str, ffprobe_stderr_str, ffprobe_status = Open3.capture3(ffprobe_command)
 
+    Rails.logger.debug "Ffprobe info return status #{ffprobe_status.exitstatus}. Command: #{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
@@ -76,6 +74,7 @@ def self.ffprobe_info(source, info, error)
         end
       end
     else
+      Rails.logger.debug "Ffprobe info error. Return status #{ffprobe_status.exitstatus}. Command: #{ffprobe_command}"
       # ffprobe std err contains info (separate on first equals(=))
       ffprobe_current_block_name = ''
       ffprobe_stdout_str.strip.split(/\r?\n|\r/).each do |line| 
@@ -96,7 +95,9 @@ 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
-
+
+    Rails.logger.debug "Wavpack info return status #{wvunpack_status.exitstatus}. Command: #{wvunpack_command}"
+
     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|
@@ -112,4 +113,33 @@ def self.wvunpack_info(source, info, error)
     end
   end
 
+  # wvunpack converts .wv files to .wav, optionally segmenting them
+  # target should be calculated based on modify_parameters by cache module
+  # modify_parameters can contain start_offset (fractions of seconds from start) and/or end_offset (fractions of seconds from start)
+  def self.wvunpack(source, target, modify_parameters = {})
+    raise ArgumentError, "Source is not a wavpack file: #{File.basename(source)}" unless source.match(/\.wv$/)
+    raise ArgumentError, "Target is not a wav file: : #{File.basename(target)}" unless target.match(/\.wav$/)
+    raise ArgumentError, "Source does not exist: #{File.basename(source)}" unless File.exists? source
+    raise ArgumentError, "Target exists: #{File.basename(target)}" unless !File.exists? source
+
+    # formatted time: hh:mm:ss.ss
+    arguments = '-t -q'
+    if modify_parameters.include? :start_offset
+      start_offset_formatted = Time.at(modify_parameters[:start_offset]).utc.strftime('%H:%M:%S.%2N')
+      arguments += ' --skip=#{start_offset_formatted}'
+    end
+
+    if modify_parameters.include? :end_offset
+      end_offset_formatted = Time.at(modify_parameters[:start_offset]).utc.strftime('%H:%M:%S.%2N')
+      arguments += ' --until=#{end_offset_formatted}'
+    end
+
+    wvunpack_command = "#{@wvunpack_path} #{arguments} \"#{source}\" \"#{target}\"" # 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
+      raise "Wvunpack exited with an error: #{wvunpack_stderr_str}"
+    end
+  end
+
 end

lib/modules/cache.rb

@@ -0,0 +1,17 @@
+module Cache
+
+  public
+
+  # calculate the target file name and path based on the modification parameters
+  def self.calculate_target_path(modify_parameters = {})
+    #Mime::Type.lookup_by_extension(
+    #QubarSite::Application.config.media_file_config
+  end
+
+  # check to see if a target file exists
+  def self.exists(source, modify_parameters = {})
+    File.exists? calculate_target_path(source, modify_parameters)
+  end
+
+  private
+end

lib/modules/spectrogram.rb

@@ -7,7 +7,6 @@ module Spectrogram
   @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")
 
   # Generate a spectrogram image from an audio file.
   # The spectrogram will be 257 pixels high, but the length is not known exactly beforehand.
@@ -18,6 +17,7 @@ def self.generate(source, target)
 
     # check for existing image, and do not overwrite
     if File.exist?(target)
+      Rails.logger.warn  "Target path for spectrogram generation already exists: #{target}."
       return [ "", "", "", source, File.exist?(source), target, File.exist?(target) ]
     end
 
@@ -28,7 +28,7 @@ def self.generate(source, target)
     stdout_str, stderr_str, status = Open3.capture3(command)
 
     # log the command
-    @my_logger.debug(command)
+    Rails.logger.debug "Spectrogram generation return status #{status.exitstatus}. Command: #{command}"
 
     # package up all the available information and return it
     result = [ stdout_str, stderr_str, status, source, File.exist?(source), target, File.exist?(target) ]

lib/modules/string.rb

@@ -0,0 +1,5 @@
+class String
+  def trim(replace_chars, substitute_chars)
+    "#{self}".gsub(/^[#{substitute_chars}]+|[#{substitute_chars}]+$/, replace_chars)
+  end
+end

vendor/bin/install_console_audio_tools.sh

@@ -0,0 +1 @@
+sudo apt-get install ffmpeg=4:0.8.3-0ubuntu0.12.04.1 mp3splt=2.4.1-0ubuntu1 sox=14.3.2-3 wavpack=4.60.1-2