Class: Mp3Info
- Inherits:
-
Object
- Object
- Mp3Info
- Defined in:
- lib/mp3info/extension_modules.rb,
lib/mp3info.rb
Overview
- License
-
Ruby
- Author
-
Guillaume Pierronnet (moumar_AT__rubyforge_DOT_org)
- Website
Defined Under Namespace
Modules: HashKeys, Mp3FileMethods
Constant Summary collapse
- VERSION =
"0.6.14"
- LAYER =
[ nil, 3, 2, 1]
- BITRATE =
{ 1 => [ [32, 64, 96, 128, 160, 192, 224, 256, 288, 320, 352, 384, 416, 448], [32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384], [32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320] ], 2 => [ [32, 48, 56, 64, 80, 96, 112, 128, 144, 160, 176, 192, 224, 256], [8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160], [8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160] ], 2.5 => [ [32, 48, 56, 64, 80, 96, 112, 128, 144, 160, 176, 192, 224, 256], [8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160], [8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160] ] }
- SAMPLERATE =
{ 1 => [ 44100, 48000, 32000 ], 2 => [ 22050, 24000, 16000 ], 2.5 => [ 11025, 12000, 8000 ] }
- CHANNEL_MODE =
[ "Stereo", "JStereo", "Dual Channel", "Single Channel"]
- GENRES =
[ "Blues", "Classic Rock", "Country", "Dance", "Disco", "Funk", "Grunge", "Hip-Hop", "Jazz", "Metal", "New Age", "Oldies", "Other", "Pop", "R&B", "Rap", "Reggae", "Rock", "Techno", "Industrial", "Alternative", "Ska", "Death Metal", "Pranks", "Soundtrack", "Euro-Techno", "Ambient", "Trip-Hop", "Vocal", "Jazz+Funk", "Fusion", "Trance", "Classical", "Instrumental", "Acid", "House", "Game", "Sound Clip", "Gospel", "Noise", "AlternRock", "Bass", "Soul", "Punk", "Space", "Meditative", "Instrumental Pop", "Instrumental Rock", "Ethnic", "Gothic", "Darkwave", "Techno-Industrial", "Electronic", "Pop-Folk", "Eurodance", "Dream", "Southern Rock", "Comedy", "Cult", "Gangsta", "Top 40", "Christian Rap", "Pop/Funk", "Jungle", "Native American", "Cabaret", "New Wave", "Psychadelic", "Rave", "Showtunes", "Trailer", "Lo-Fi", "Tribal", "Acid Punk", "Acid Jazz", "Polka", "Retro", "Musical", "Rock & Roll", "Hard Rock", "Folk", "Folk/Rock", "National Folk", "Swing", "Fast-Fusion", "Bebob", "Latin", "Revival", "Celtic", "Bluegrass", "Avantgarde", "Gothic Rock", "Progressive Rock", "Psychedelic Rock", "Symphonic Rock", "Slow Rock", "Big Band", "Chorus", "Easy Listening", "Acoustic", "Humour", "Speech", "Chanson", "Opera", "Chamber Music", "Sonata", "Symphony", "Booty Bass", "Primus", "Porn Groove", "Satire", "Slow Jam", "Club", "Tango", "Samba", "Folklore", "Ballad", "Power Ballad", "Rhythmic Soul", "Freestyle", "Duet", "Punk Rock", "Drum Solo", "A capella", "Euro-House", "Dance Hall", "Goa", "Drum & Bass", "Club House", "Hardcore", "Terror", "Indie", "BritPop", "NegerPunk", "Polsk Punk", "Beat", "Christian Gangsta", "Heavy Metal", "Black Metal", "Crossover", "Contemporary C", "Christian Rock", "Merengue", "Salsa", "Thrash Metal", "Anime", "JPop", "SynthPop" ]
- TAG1_SIZE =
128
- TAG_MAPPING_2_2 =
map to fill the “universal” tag (#tag attribute) for id3v2.2
{ "title" => "TT2", "artist" => "TP1", "album" => "TAL", "year" => "TYE", "tracknum" => "TRK", "comments" => "COM", "genre_s" => "TCO" }
- TAG_MAPPING_2_3 =
for id3v2.3 and 2.4
{ "title" => "TIT2", "artist" => "TPE1", "album" => "TALB", "year" => "TYER", "tracknum" => "TRCK", "comments" => "COMM", "genre_s" => "TCON" }
- SAMPLES_PER_FRAME =
[ nil, {1=>384, 2=>384, 2.5=>384}, # Layer I {1=>1152, 2=>1152, 2.5=>1152}, # Layer II {1=>1152, 2=>576, 2.5=>576} # Layer III ]
Instance Attribute Summary collapse
-
#bitrate ⇒ Object
readonly
bitrate in kbps.
-
#channel_mode ⇒ Object
readonly
channel mode => “Stereo”, “JStereo”, “Dual Channel” or “Single Channel”.
-
#error_protection ⇒ Object
readonly
error protection => true or false.
-
#filename ⇒ Object
readonly
the original filename.
-
#header ⇒ Object
readonly
Hash representing values in the MP3 frame header.
-
#layer ⇒ Object
readonly
layer = 1, 2, or 3.
-
#length ⇒ Object
readonly
length in seconds as a Float.
-
#mpeg_version ⇒ Object
readonly
mpeg version = 1 or 2.
-
#samplerate ⇒ Object
readonly
samplerate in Hz.
-
#tag ⇒ Object
readonly
a sort of “universal” tag, regardless of the tag version, 1 or 2, with the same keys as @tag1 this tag has priority over @tag1 and @tag2 when writing the tag with #close.
-
#tag1 ⇒ Object
id3v1 tag as a Hash.
-
#tag2 ⇒ Object
id3v2 tag attribute as an ID3v2 object.
-
#vbr ⇒ Object
readonly
variable bitrate => true or false.
Class Method Summary collapse
-
.hastag1?(filename) ⇒ Boolean
Test the presence of an id3v1 tag in file
filename
. -
.hastag2?(filename) ⇒ Boolean
Test the presence of an id3v2 tag in file
filename
. -
.open(*params) ⇒ Object
“block version” of Mp3Info::new().
-
.removetag1(filename) ⇒ Object
Remove id3v1 tag from
filename
. -
.removetag2(filename) ⇒ Object
Remove id3v2 tag from
filename
.
Instance Method Summary collapse
-
#audio_content ⇒ Object
this method returns the “audio-only” data boundaries of the file, i.e.
-
#close ⇒ Object
Flush pending modifications to tags and close the file.
-
#each_frame ⇒ Object
iterates over each mpeg frame over the file, allowing you to write some funny things, like an mpeg lossless cutter, or frame counter, or whatever you like ;)
frame
is a hash with the following keys: :layer, :bitrate, :samplerate, :mpeg_version, :padding and :size (in bytes). -
#flush ⇒ Object
close and reopen the file, i.e.
-
#frame_length ⇒ Object
return the length in seconds of one frame.
-
#hastag1? ⇒ Boolean
Does the file has an id3v1 tag?.
-
#hastag2? ⇒ Boolean
Does the file has an id3v2 tag?.
-
#hastag? ⇒ Boolean
Does the file has an id3v1 or v2 tag?.
-
#initialize(filename, options = {}) ⇒ Mp3Info
constructor
Instantiate Mp3Info object with name
filename
. -
#reload ⇒ Object
reload (or load for the first time) the file from disk.
-
#removetag1 ⇒ Object
Remove id3v1 from mp3.
-
#removetag2 ⇒ Object
Remove id3v2 from mp3.
-
#rename(new_filename) ⇒ Object
write to another filename at close().
-
#to_s ⇒ Object
inspect inside Mp3Info.
Constructor Details
#initialize(filename, options = {}) ⇒ Mp3Info
Instantiate Mp3Info object with name filename
. options hash is used for ID3v2#new. Specify :parse_tags => false to disable the processing of the tags (read and write). Specify :parse_mp3 => false to disable processing of the mp3
196 197 198 199 200 201 202 203 204 |
# File 'lib/mp3info.rb', line 196 def initialize(filename, = {}) warn("#{self.class}::new() does not take block; use #{self.class}::open() instead") if block_given? @filename = filename = {:parse_mp3 => true, :parse_tags => true}.update() @tag_parsing_enabled = .delete(:parse_tags) @mp3_parsing_enabled = .delete(:parse_mp3) @id3v2_options = reload end |
Instance Attribute Details
#bitrate ⇒ Object (readonly)
bitrate in kbps
118 119 120 |
# File 'lib/mp3info.rb', line 118 def bitrate @bitrate end |
#channel_mode ⇒ Object (readonly)
channel mode => “Stereo”, “JStereo”, “Dual Channel” or “Single Channel”
124 125 126 |
# File 'lib/mp3info.rb', line 124 def channel_mode @channel_mode end |
#error_protection ⇒ Object (readonly)
error protection => true or false
144 145 146 |
# File 'lib/mp3info.rb', line 144 def error_protection @error_protection end |
#filename ⇒ Object (readonly)
the original filename
159 160 161 |
# File 'lib/mp3info.rb', line 159 def filename @filename end |
#header ⇒ Object (readonly)
Hash representing values in the MP3 frame header. Keys are one of the following:
-
:private (boolean)
-
:copyright (boolean)
-
:original (boolean)
-
:padding (boolean)
-
:error_protection (boolean)
-
:mode_extension (integer in the 0..3 range)
-
:emphasis (integer in the 0..3 range)
detailled explanation can be found here: www.mp3-tech.org/programmer/frame_header.html
138 139 140 |
# File 'lib/mp3info.rb', line 138 def header @header end |
#layer ⇒ Object (readonly)
layer = 1, 2, or 3
115 116 117 |
# File 'lib/mp3info.rb', line 115 def layer @layer end |
#length ⇒ Object (readonly)
length in seconds as a Float
141 142 143 |
# File 'lib/mp3info.rb', line 141 def length @length end |
#mpeg_version ⇒ Object (readonly)
mpeg version = 1 or 2
112 113 114 |
# File 'lib/mp3info.rb', line 112 def mpeg_version @mpeg_version end |
#samplerate ⇒ Object (readonly)
samplerate in Hz
121 122 123 |
# File 'lib/mp3info.rb', line 121 def samplerate @samplerate end |
#tag ⇒ Object (readonly)
a sort of “universal” tag, regardless of the tag version, 1 or 2, with the same keys as @tag1 this tag has priority over @tag1 and @tag2 when writing the tag with #close
148 149 150 |
# File 'lib/mp3info.rb', line 148 def tag @tag end |
#tag1 ⇒ Object
id3v1 tag as a Hash. You can modify it, it will be written when calling “close” method.
152 153 154 |
# File 'lib/mp3info.rb', line 152 def tag1 @tag1 end |
#tag2 ⇒ Object
id3v2 tag attribute as an ID3v2 object. You can modify it, it will be written when calling “close” method.
156 157 158 |
# File 'lib/mp3info.rb', line 156 def tag2 @tag2 end |
#vbr ⇒ Object (readonly)
variable bitrate => true or false
127 128 129 |
# File 'lib/mp3info.rb', line 127 def vbr @vbr end |
Class Method Details
.hastag1?(filename) ⇒ Boolean
Test the presence of an id3v1 tag in file filename
162 163 164 165 166 167 |
# File 'lib/mp3info.rb', line 162 def self.hastag1?(filename) File.open(filename,"rb") { |f| f.seek(-TAG1_SIZE, File::SEEK_END) f.read(3) == "TAG" } end |
.hastag2?(filename) ⇒ Boolean
Test the presence of an id3v2 tag in file filename
170 171 172 173 174 |
# File 'lib/mp3info.rb', line 170 def self.hastag2?(filename) File.open(filename,"rb") { |f| f.read(3) == "ID3" } end |
.open(*params) ⇒ Object
“block version” of Mp3Info::new()
261 262 263 264 265 266 267 268 269 270 271 272 273 274 |
# File 'lib/mp3info.rb', line 261 def self.open(*params) m = self.new(*params) ret = nil if block_given? begin ret = yield(m) ensure m.close end else ret = m end ret end |
.removetag1(filename) ⇒ Object
Remove id3v1 tag from filename
177 178 179 180 181 182 |
# File 'lib/mp3info.rb', line 177 def self.removetag1(filename) if self.hastag1?(filename) newsize = File.size(filename) - TAG1_SIZE File.open(filename, "rb+") { |f| f.truncate(newsize) } end end |
.removetag2(filename) ⇒ Object
Remove id3v2 tag from filename
185 186 187 188 189 |
# File 'lib/mp3info.rb', line 185 def self.removetag2(filename) self.open(filename) do |mp3| mp3.tag2.clear end end |
Instance Method Details
#audio_content ⇒ Object
this method returns the “audio-only” data boundaries of the file, i.e. content stripped form tags. Useful to compare 2 files with the same audio content but with differents tags. Returned value is an array
- position_in_the_file, length_of_the_data
312 313 314 315 316 317 318 319 320 321 322 323 |
# File 'lib/mp3info.rb', line 312 def audio_content pos = 0 length = File.size(@filename) if hastag1? length -= TAG1_SIZE end if hastag2? pos = @tag2.io_position length -= @tag2.io_position end [pos, length] end |
#close ⇒ Object
Flush pending modifications to tags and close the file
331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 |
# File 'lib/mp3info.rb', line 331 def close puts "close" if $DEBUG if !@tag_parsing_enabled return end if @tag != @tag_orig puts "@tag has changed" if $DEBUG # @tag1 has precedence over @tag if @tag1 == @tag1_orig @tag.each do |k, v| @tag1[k] = v end end # ruby-mp3info can only write v2.3 tags TAG_MAPPING_2_3.each do |key, tag2_name| @tag2.delete(TAG_MAPPING_2_2[key]) @tag2[tag2_name] = @tag[key] if @tag[key] end end if @tag1 != @tag1_orig puts "@tag1 has changed" if $DEBUG raise(Mp3InfoError, "file is not writable") unless File.writable?(@filename) #@tag1_orig.update(@tag1) @tag1_orig = @tag1.dup File.open(@filename, 'rb+') do |file| if @tag1_orig.empty? newsize = file.stat.size - TAG1_SIZE file.truncate(newsize) else file.seek(-TAG1_SIZE, File::SEEK_END) t = file.read(3) if t != 'TAG' #append new tag file.seek(0, File::SEEK_END) file.write('TAG') end str = [ @tag1_orig["title"]||"", @tag1_orig["artist"]||"", @tag1_orig["album"]||"", ((@tag1_orig["year"] != 0) ? ("%04d" % @tag1_orig["year"].to_i) : "\0\0\0\0"), @tag1_orig["comments"]||"", 0, @tag1_orig["tracknum"]||0, @tag1_orig["genre"]||255 ].pack("Z30Z30Z30Z4Z28CCC") file.write(str) end end end if @tag2.changed? puts "@tag2 has changed" if $DEBUG raise(Mp3InfoError, "file is not writable") unless File.writable?(@filename) tempfile_name = nil File.open(@filename, 'rb+') do |file| #if tag2 already exists, seek to end of it if @tag2.parsed? file.seek(@tag2.io_position) end # if @file.read(3) == "ID3" # version_maj, version_min, flags = @file.read(3).unpack("CCB4") # unsync, ext_header, experimental, footer = (0..3).collect { |i| flags[i].chr == '1' } # tag2_len = @file.get_syncsafe # @file.seek(@file.get_syncsafe - 4, IO::SEEK_CUR) if ext_header # @file.seek(tag2_len, IO::SEEK_CUR) # end tempfile_name = @filename + ".tmp" File.open(tempfile_name, "wb") do |tempfile| unless @tag2.empty? tempfile.write(@tag2.to_bin) end bufsiz = file.stat.blksize || 4096 while buf = file.read(bufsiz) tempfile.write(buf) end end end File.rename(tempfile_name, @filename) end end |
#each_frame ⇒ Object
iterates over each mpeg frame over the file, allowing you to write some funny things, like an mpeg lossless cutter, or frame counter, or whatever you like ;) frame
is a hash with the following keys: :layer, :bitrate, :samplerate, :mpeg_version, :padding and :size (in bytes)
436 437 438 439 440 441 442 443 444 445 446 447 448 |
# File 'lib/mp3info.rb', line 436 def each_frame File.open(@filename, 'rb') do |file| file.seek(@first_frame_pos, File::SEEK_SET) loop do head = file.read(4).unpack("N").first frame = Mp3Info.get_frames_infos(head) file.seek(frame[:size] -4, File::SEEK_CUR) yield frame #puts "frame #{frame_count} len #{frame[:length]} br #{frame[:bitrate]} @file.pos #{@file.pos}" break if file.eof? end end end |
#flush ⇒ Object
close and reopen the file, i.e. commit changes to disk and reload it
419 420 421 422 |
# File 'lib/mp3info.rb', line 419 def flush close reload end |
#frame_length ⇒ Object
return the length in seconds of one frame
326 327 328 |
# File 'lib/mp3info.rb', line 326 def frame_length SAMPLES_PER_FRAME[@layer][@mpeg_version] / Float(@samplerate) end |
#hastag1? ⇒ Boolean
Does the file has an id3v1 tag?
294 295 296 |
# File 'lib/mp3info.rb', line 294 def hastag1? !@tag1.empty? end |
#hastag2? ⇒ Boolean
Does the file has an id3v2 tag?
299 300 301 |
# File 'lib/mp3info.rb', line 299 def hastag2? @tag2.parsed? end |
#hastag? ⇒ Boolean
Does the file has an id3v1 or v2 tag?
289 290 291 |
# File 'lib/mp3info.rb', line 289 def hastag? hastag1? || hastag2? end |
#reload ⇒ Object
reload (or load for the first time) the file from disk
207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 |
# File 'lib/mp3info.rb', line 207 def reload raise(Mp3InfoError, "empty file") unless File.size?(@filename) @header = {} @file = File.new(filename, "rb") @file.extend(Mp3FileMethods) @tag1 = @tag = @tag1_orig = @tag_orig = {} @tag1.extend(HashKeys) @tag2 = ID3v2.new(@id3v2_options) begin if @tag_parsing_enabled @tag1_orig = @tag1.dup if hastag1? @tag = @tag1.dup end if hastag2? @tag = {} # creation of a sort of "universal" tag, regardless of the tag version tag2_mapping = @tag2.version =~ /^2\.2/ ? TAG_MAPPING_2_2 : TAG_MAPPING_2_3 tag2_mapping.each do |key, tag2_name| tag_value = (@tag2[tag2_name].is_a?(Array) ? @tag2[tag2_name].first : @tag2[tag2_name]) next unless tag_value @tag[key] = tag_value.is_a?(Array) ? tag_value.first : tag_value if %w{year tracknum}.include?(key) @tag[key] = tag_value.to_i end # this is a special case with id3v2.2, which uses # old fashionned id3v1 genres if tag2_name == "TCO" && tag_value =~ /^\((\d+)\)$/ @tag["genre_s"] = GENRES[$1.to_i] end end end @tag.extend(HashKeys) @tag_orig = @tag.dup end if @mp3_parsing_enabled parse_mp3 end ensure @file.close end end |
#removetag1 ⇒ Object
Remove id3v1 from mp3
277 278 279 280 |
# File 'lib/mp3info.rb', line 277 def removetag1 @tag1.clear self end |
#removetag2 ⇒ Object
Remove id3v2 from mp3
283 284 285 286 |
# File 'lib/mp3info.rb', line 283 def removetag2 @tag2.clear self end |
#rename(new_filename) ⇒ Object
write to another filename at close()
304 305 306 |
# File 'lib/mp3info.rb', line 304 def rename(new_filename) @filename = new_filename end |
#to_s ⇒ Object
inspect inside Mp3Info
425 426 427 428 429 430 |
# File 'lib/mp3info.rb', line 425 def to_s s = "MPEG #{@mpeg_version} Layer #{@layer} #{@vbr ? "VBR" : "CBR"} #{@bitrate} Kbps #{@channel_mode} #{@samplerate} Hz length #{@length} sec. header #{@header.inspect} " s << "tag1: "+@tag1.inspect+"\n" if hastag1? s << "tag2: "+@tag2.inspect+"\n" if hastag2? s end |