walkgirl/audiofile.rb

   1 ############################################################################
   2 #    Copyright (C) 2008 by Rafał Rzepecki   #
   3 #    divided.mind@gmail.com   #
   4 #                                                                          #
   5 #    This program is free software; you can redistribute it and#or modify  #
   6 #    it under the terms of the GNU General Public License as published by  #
   7 #    the Free Software Foundation; either version 2 of the License, or     #
   8 #    (at your option) any later version.                                   #
   9 #                                                                          #
  10 #    This program is distributed in the hope that it will be useful,       #
  11 #    but WITHOUT ANY WARRANTY; without even the implied warranty of        #
  12 #    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         #
  13 #    GNU General Public License for more details.                          #
  14 #                                                                          #
  15 #    You should have received a copy of the GNU General Public License     #
  16 #    along with this program; if not, write to the                         #
  17 #    Free Software Foundation, Inc.,                                       #
  18 #    59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             #
  19 ############################################################################
  20
  21 require 'id3'
  22
  23 module NetworkWalkman
  24   class AudioFile
  25     MPEG_VERSION = [:v2_5, :reserved, :v2, :v1]
  26     attr_accessor :length, :frames, :tags
  27     attr_reader :filename, :slot
  28     class FromDevice < AudioFile
  29       attr_reader :encoding
  30       def initialize(*args)
  31         @length, @frames, @tags, @filename, @slot, @encoding = args
  32       end
  33       def scramble(outfile)
  34         # noop
  35       end
  36     end
  37
  38     def self.open(filename)
  39       File.open(filename) { |f|
  40         begin
  41           slot = filename.match("1([0-9a-f]{7})\.")[1].hex
  42           tag_data = f.read(3072)
  43           f.seek(0xc22)
  44           encoding, _, length, frames = f.read(10).unpack("CCNN")
  45           f.close
  46           tag_data[0..4] = ["ID3", 4, 0].pack("a3CC")
  47           tags = ID3::Tag2.new
  48           tags.raw = tag_data
  49           tags.parse!
  50           tags.each { |key, tag|
  51             begin
  52               tags[key] = tag.recode(0)
  53             rescue
  54               begin # try harder to recode
  55                 tag = tag.clone
  56                 tag["text"] = tag["text"][0...(tag["text"].length-1)]
  57                 tags[key] = tag.recode(0)
  58               rescue
  59               end
  60             end
  61           }
  62           return FromDevice.new(length, frames, tags, filename, slot, encoding)
  63         rescue
  64           STDERR.puts("Corrupted file #{filename}")
  65         end
  66       }
  67     end
  68
  69     def self.openAll(mount_point)
  70       files = []
  71       Dir[File.join([mount_point, 'omgaudio', '10f*'])].sort.each { |dir|
  72         Dir[File.join([dir, "*.oma"])].sort.each do |filename|
  73           af = AudioFile.open(filename)
  74           files[af.slot-1] = af if af
  75         end
  76       }
  77       files
  78     end
  79
  80     def encoding
  81       (mpeg_version << 6) |
  82       (mpeg_layer   << 4) |
  83       (bitrate_id       )
  84     end
  85
  86     def save
  87       File.open(filename, 'w+') {|outfile|
  88         tag = ID3::Tag2.new
  89         if tags # convert to ID3v2
  90           tags.each { |key, value|
  91             tag[key] = value
  92             tag[key] = tag[key].recode(2) if tag[key]["text"]
  93           }
  94         end
  95         tag = tag.dump
  96         tag[0...10] = ["ea3", 3, 0x1776].pack("a3c@8n")
  97         outfile.sysseek(0, IO::SEEK_SET)
  98         outfile.syswrite [tag].pack("a3072")
  99         # write out header
 100         outfile.syswrite "EA3"
 101         outfile.syswrite [2, 0, 0x60, 0xff, 0xfe, 1, 0x0f, 0x50, 0x00].pack("c5@9c4")
 102         outfile.syswrite [0, 4, 0, 0, 0, 1, 2, 3, 0xc8, 0xd8, 0x36, 0xd8, 0x11, 0x22, 0x33, 0x44].pack("c*")
 103         outfile.syswrite [0x03, 0x80, encoding, 10, length, frames, 0].pack("c4N3")
 104         outfile.syswrite [0,0,0,0].pack("N4")
 105         outfile.syswrite [0,0,0,0].pack("N4")
 106         outfile.syswrite [0,0,0,0].pack("N4")
 107         outfile.sysseek outfile.tell
 108         scramble(outfile)
 109       }
 110     end
 111
 112     def initialize
 113     end
 114     def track_length
 115       @length
 116     end
 117     def tags
 118       @tags
 119     end
 120     def frame_count
 121       @frames
 122     end
 123   end
 124 end