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 =
"0.6.15"
- 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 unless used with a StringIO.
-
#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_or_io) ⇒ Boolean
Test the presence of an id3v1 tag in file or StringIO
filename_or_io
. -
.hastag2?(filename_or_io) ⇒ Boolean
Test the presence of an id3v2 tag in file or StringIO
filename_or_io
. -
.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 not used when source IO is a StringIO.
-
#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_or_io, 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_or_io, 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
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# File 'lib/mp3info.rb', line 219 def initialize(filename_or_io, = {}) warn("#{self.class}::new() does not take block; use #{self.class}::open() instead") if block_given? @filename_or_io = filename_or_io = {: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
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# File 'lib/mp3info.rb', line 118 def bitrate @bitrate end |
#channel_mode ⇒ Object (readonly)
channel mode => “Stereo”, “JStereo”, “Dual Channel” or “Single Channel”
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# File 'lib/mp3info.rb', line 124 def channel_mode @channel_mode end |
#error_protection ⇒ Object (readonly)
error protection => true or false
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# File 'lib/mp3info.rb', line 144 def error_protection @error_protection end |
#filename ⇒ Object (readonly)
the original filename unless used with a StringIO
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# 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
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# File 'lib/mp3info.rb', line 138 def header @header end |
#layer ⇒ Object (readonly)
layer = 1, 2, or 3
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# File 'lib/mp3info.rb', line 115 def layer @layer end |
#length ⇒ Object (readonly)
length in seconds as a Float
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# File 'lib/mp3info.rb', line 141 def length @length end |
#mpeg_version ⇒ Object (readonly)
mpeg version = 1 or 2
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# File 'lib/mp3info.rb', line 112 def mpeg_version @mpeg_version end |
#samplerate ⇒ Object (readonly)
samplerate in Hz
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# 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
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# 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.
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# 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.
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# File 'lib/mp3info.rb', line 156 def tag2 @tag2 end |
#vbr ⇒ Object (readonly)
variable bitrate => true or false
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# File 'lib/mp3info.rb', line 127 def vbr @vbr end |
Class Method Details
.hastag1?(filename_or_io) ⇒ Boolean
Test the presence of an id3v1 tag in file or StringIO filename_or_io
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# File 'lib/mp3info.rb', line 162 def self.hastag1?(filename_or_io) if filename_or_io.is_a?(StringIO) io = filename_or_io io.rewind else io = File.new(filename_or_io, "rb") end hastag1 = false begin io.seek(-TAG1_SIZE, File::SEEK_END) hastag1 = io.read(3) == "TAG" ensure io.close if io.is_a?(File) end hastag1 end |
.hastag2?(filename_or_io) ⇒ Boolean
Test the presence of an id3v2 tag in file or StringIO filename_or_io
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# File 'lib/mp3info.rb', line 181 def self.hastag2?(filename_or_io) if filename_or_io.is_a?(StringIO) io = filename_or_io io.rewind else io = File.new(filename_or_io,"rb") end hastag2 = false begin hastag2 = io.read(3) == "ID3" ensure io.close if io.is_a?(File) end hastag2 end |
.open(*params) ⇒ Object
“block version” of Mp3Info::new()
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# File 'lib/mp3info.rb', line 300 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
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# File 'lib/mp3info.rb', line 200 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
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# File 'lib/mp3info.rb', line 208 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
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# File 'lib/mp3info.rb', line 352 def audio_content pos = 0 length = @io_size 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 not used when source IO is a StringIO
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# File 'lib/mp3info.rb', line 372 def close puts "close" if $DEBUG return unless @io_is_a_file 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_or_io) #@tag1_orig.update(@tag1) @tag1_orig = @tag1.dup File.open(@filename_or_io, 'rb+') do |file| if @tag1_orig.empty? newsize = @io_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_or_io) tempfile_name = nil File.open(@filename_or_io, 'rb+') do |file| #if tag2 already exists, seek to end of it if @tag2.parsed? file.seek(@tag2.io_position) end # if @io.read(3) == "ID3" # version_maj, version_min, flags = @io.read(3).unpack("CCB4") # unsync, ext_header, experimental, footer = (0..3).collect { |i| flags[i].chr == '1' } # tag2_len = @io.get_syncsafe # @io.seek(@io.get_syncsafe - 4, IO::SEEK_CUR) if ext_header # @io.seek(tag2_len, IO::SEEK_CUR) # end tempfile_name = @filename_or_io + ".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_or_io) 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)
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# File 'lib/mp3info.rb', line 479 def each_frame @io.seek(@first_frame_pos, File::SEEK_SET) loop do head = @io.read(4).unpack("N").first frame = Mp3Info.get_frames_infos(head) @io.seek(frame[:size] -4, File::SEEK_CUR) yield frame #puts "frame #{frame_count} len #{frame[:length]} br #{frame[:bitrate]} @io.pos #{@io.pos}" break if @io.eof? end end |
#flush ⇒ Object
close and reopen the file, i.e. commit changes to disk and reload it (only works with “true” files, not StringIO ones)
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# File 'lib/mp3info.rb', line 461 def flush return unless @io_is_a_file close reload end |
#frame_length ⇒ Object
return the length in seconds of one frame
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# File 'lib/mp3info.rb', line 366 def frame_length SAMPLES_PER_FRAME[@layer][@mpeg_version] / Float(@samplerate) end |
#hastag1? ⇒ Boolean
Does the file has an id3v1 tag?
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# File 'lib/mp3info.rb', line 333 def hastag1? !@tag1.empty? end |
#hastag2? ⇒ Boolean
Does the file has an id3v2 tag?
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# File 'lib/mp3info.rb', line 338 def hastag2? @tag2.parsed? end |
#hastag? ⇒ Boolean
Does the file has an id3v1 or v2 tag?
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# File 'lib/mp3info.rb', line 328 def hastag? hastag1? || hastag2? end |
#reload ⇒ Object
reload (or load for the first time) the file from disk
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# File 'lib/mp3info.rb', line 230 def reload @header = {} if @filename_or_io.is_a?(String) @io_is_a_file = true @io = File.new(@filename_or_io, "rb") @io_size = @io.stat.size @filename = @filename_or_io elsif @filename_or_io.is_a?(StringIO) @io_is_a_file = false @io = @filename_or_io @io_size = @io.size @filename = nil end if @io_size == 0 raise(Mp3InfoError, "empty file or IO") end @io.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 if @io_is_a_file @io.close end end end |
#removetag1 ⇒ Object
Remove id3v1 from mp3
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# File 'lib/mp3info.rb', line 316 def removetag1 @tag1.clear self end |
#removetag2 ⇒ Object
Remove id3v2 from mp3
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# File 'lib/mp3info.rb', line 322 def removetag2 @tag2.clear self end |
#rename(new_filename) ⇒ Object
write to another filename at close()
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# File 'lib/mp3info.rb', line 343 def rename(new_filename) raise(Mp3InfoError, "cannot rename an IO") unless @io_is_a_file @filename = new_filename end |
#to_s ⇒ Object
inspect inside Mp3Info
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# File 'lib/mp3info.rb', line 468 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 |