Provided by: mp3info_0.8.4-9.2_i386 bug
 

NAME

        mp3info - MP3 technical info viewer and ID3 tag editor
 

SYNOPSIS

        mp3info [ -h | -G ]
 
        mp3info [-x] [-F] [-r a|m|v] [-p FORMAT_STRING] file...
 
        mp3info [-d] file...
 
        mp3info  [-i]  [-t title] [-a artist] [-l album] [-y year] [-c comment]
        [-n track] [-g genre] file...
 

DESCRIPTION

        mp3info is a utility used to read and modify the ID3 tags in MPEG layer
        3  (MP3)  files.   It  can  also (optionally) display various technical
        attributes of the MP3 file.
 

OPTIONS

        -a artist
               Specify ID3 artist name
 
        -c comment
               Specify ID3 comment
 
        -g genre
               Specify ID3 genre (use -G option for a list  of  valid  genres).
               You may specify either a genre name or a number.
 
        -l album
               Specify ID3 album name
 
        -n track
               Specify ID3 v1.1 track number
 
        -t title
               Specify ID3 track title
 
        -y year
               Specify ID3 copyright year
 
        -G     Display  a  list  of  valid  genres and their associated numeric
               codes. These are the only values accepted by the -g switch.
 
        -h     Display a help page
 
        -x     Display technical attributes of the MP3 file
 
        -r a|m|v
               Report bit rate of Variable Bit Rate (VBR) files as one  of  the
               following  (See  the  section  below entitled Bit Rates for more
               information):
 
               a - Average bit rate [float](Note: this option also  causes  the
                      bit  rates  of  non-VBR files to be displayed as floating
                      point values).
               m - Median bit rate [integer]
               v - Simply  use  the  word  ’Variable’  [string]  (this  is  the
                      default).
 
        -i     Edit ID3 tag interactively (uses curses/ncurses functions)
 
        -d     Delete ID3 tag (if one exists)
 
        -f     Force  Mode: Treat all files as MP3s even if MP3 frames can’t be
               found
 
        -F     Do a Full scan for technical information (see the section  Speed
               Considerations below for more information)
 
        -p "FORMAT_STRING"
 
               Print  MP3 attributes according to FORMAT_STRING.  FORMAT_STRING
               is similar to a printf(3) format string in that  it  is  printed
               verbatim   except  for  the  following  conversions  and  escape
               sequences. Any conversion specifier may optionally  include  the
               various alignment, precision, and field width modifiers accepted
               by printf(3).  See the EXAMPLES section below  for  examples  of
               how format strings are used in mp3info.
 
               Conversion Specifiers
 
                  %f     Filename without the path [string]
                  %F     Filename with the path [string]
                  %k     File size in KB [integer]
                  %a     Artist [string]
                  %c     Comment [string]
                  %g     Musical genre [string]
                  %G     Musical genre number [integer]
                  %l     Album name [string]
                  %n     Track [integer]
                  %t     Track Title [string]
                  %y     Year [string]
                  %C     Copyright flag [string]
                  %e     Emphasis [string]
                  %E     CRC Error protection [string]
                  %L     MPEG Layer [string]
                  %O     Original material flag [string]
                  %o     Stereo/mono mode [string]
                  %p     Padding [string]
                  %v     MPEG Version [float]
                  %u     Number of good audio frames [integer]
                  %b     Number of corrupt audio frames [integer]
                  %Q     Sampling frequency in Hz [integer]
                  %q     Sampling frequency in kHz [integer]
                  %r     Bit  Rate  in  kbps  (type  and meaning affected by -r
                         option)
                  %m     Playing time: minutes only [integer]
                  %s     Playing time: seconds only [integer] (usually used  in
                         conjunction with %m)
                  %S     Total playing time in seconds [integer]
                  %%     A single percent sign
 
               Escape Sequences
 
                  \n     Newline
                  \t     Horizontal tab
                  \v     Vertical tab
                  \b     Backspace
                  \r     Carriage Return
                  \f     Form Feed
                  \a     Audible Alert (terminal bell)
                  \xhh   Any  arbitrary  character specified by the hexidecimal
                         number hh
                  \ooo   Any arbitrary character specified by the octal  number
                         ooo
                  \\     A single backslash character
 

USAGE

        Specifying  MP3  files  without any other options displays the existing
        ID3 tag (if any).
 
        Specifying a track number of 0 reverts an ID3 tag to 1.0 format
 
        Non-specified ID3 fields, if existant, will remain unchanged.
 
        Genres can be specified as numbers or names: -g 17 same as -g Rock
 
        Multiple word fields must be enclosed in quotes (eg: -t "A title")
 

NOTES

        Speed Considerations
               In order to  determine  certain  technical  attributes  (playing
               time, number of frames, number of bad frames, and in a few cases
               the bit rate) with absolute certainty, it would be necessary  to
               read  the  entire  MP3  file.   Mp3info  normally tries to speed
               things up by reading a handful of frames from various points  in
               the  file and estimating the statistics for the rest of the file
               based on those samples.  Usually, this results in very  accurate
               estimates.   Audio playing times are usually off by no more than
               a second, and the number of frames is off  by  less  than  0.1%.
               Often  the  estimates agree exactly with the full scans.  Never‐
               theless, the user may wish to ensure that she is  getting  exact
               information.
 
               One  should  specify  the -F switch if one wants mp3info to read
               the entire MP3 file when  determining  this  information.   Note
               that  a  full  scan  will only affect mp3info’s output if the -x
               switch is used or the -p switch is used with a  FORMAT_SPECIFIER
               containing  %m,  %s, %S, %u or (rarely) %r.  Using the -F switch
               under other conditions will only slow down mp3info.   Also  note
               that  a  FORMAT_SPECIFIER  containing  %b or a VBR MP3 file will
               automatically trigger a full scan even if the -F switch  is  not
               used.
 
        Bit Rates
               MP3  files  are  made up of many (usally several thousand) audio
               blocks called ’frames’.  Each of these frames is  encoded  at  a
               specific  ’bit  rate’  which  determines both the quality of the
               sound and the size of the frame itself.   Bit  rates  can  range
               from  8  Kb/s  (kilobits per second) to 320 Kb/s.  Note that the
               MP3 specification only allows 14 discreet bit rates for  an  MP3
               file,  so, for instance, a stereo MP3 could have frames with bit
               rates of 128 Kb/s and 160 Kb/s, but nowhere in between.
 
               Audio frames with high bit rates sound much  better  than  those
               with  lower  bit  rates, but take up more space.  Obviously, one
               would like to use a bit rate that is only high enough  to  main‐
               tain  a  comfortable  level of audio quality.  Normally, all the
               frames in an MP3 file are encoded at the same bit rate.   A  few
               MP3  files, however, are encoded such that the bit rate may vary
               from one frame to the next.  These MP3 files are called Variable
               Bit  Rate (or VBR) files.   Since VBR files do not have one sin‐
               gle bit rate, attempting to report the bit rate of the file as a
               whole  can  be problematic.  Consequently, mp3info allows you to
               specify how you want this value reported.
 
               The default is to simply print the word ’Variable’ where the bit
               rate  would  normally  appear.   Another  option is to print the
               mathematical average of all the frames.  This has the  advantage
               of  being  completely  accurate,  but the number printed may not
               correspond to one of the 14 discreet bit  rates  that  would  be
               allowed  for that file.  The third alternative solves that prob‐
               lem by allowing the bit rate to be reported as  the  median  bit
               rate  which is what you would get if you lined up all the frames
               in the file by bit rate from lowest to highest  and  picked  the
               frame closest to the middle of the line.
 
               For  more  specific usage information, see the -r switch and the
               %r conversion specifier  under  the  description  of  -p’s  FOR‐
               MAT_SPECIFIER.
 

EXAMPLES

        Display existing ID3 tag information (if any) in song.mp3
 
               mp3info song.mp3
 
        Set  the  title,  author  and  genre  of  song.mp3.  (All  other fields
        unchanged)
 
               mp3info -t "Song Title" -a Author -g "Rock & Roll" song.mp3
 
        Set the album field of all MP3 files in the current directory  to  "The
        White Album"
 
               mp3info -l "The White Album" *.mp3
 
        Delete the entire ID3 tag from song1.mp3 and song2.mp3
 
               mp3info -d song1.mp3 song2.mp3
 
        Delete the comment field from the ID3 tags of all MP3 files in the cur‐
        rent directory. (All other fields unchanged)
 
               mp3info -c "" *.mp3
 
        Display the Title, Artist, Album, and Year of all MP3 files in the cur‐
        rent directory.  We include the labels ’File’, etc. and insert newlines
        (\n) to make things more readable for humans:
 
               mp3info -p "File: %f\nTitle:  %t\nArtist:  %a\nAlbum:  %l\nYear:
               %y\n\n" *.mp3
 
        Say  you  want to build a spreadsheet of your MP3 files.  Here’s a com‐
        mand you might use to help you accomplish that.  Most spreadsheet  pro‐
        grams  will import an ASCII file and treat a given character as a field
        separator.  A commonly used field separator is the tab character.   For
        each MP3 file in the current directory, we want to output the filename,
        title, artist, and album on a single line and have the fields separated
        by  a tab (\t) character.  Note that you must include a newline (\n) at
        the end of the format string in order to get each file’s information on
        a separate line.  Here’s the command:
 
               mp3info -p "%f\t%t\t%a\t%l\t%y\n" *.mp3
 
        Some  spreadsheets or other software may allow importing data from flat
        files where each field is a specific width.  Here’s  where  the  format
        modifers   come   into  play.   This  next  command  outputs  the  same
        information as the command above, but uses fixed-width  fields  instead
        of  tab  separators.   The  filename  field is defined as 50 characters
        wide, the title field is defined as 31 characters wide, and so on.
 
               mp3info -p "%50f%31t%31a%31l%4y\n" *.mp3
 
        The problem with the output of this command is  that  all  strings  are
        normally right- justified within their fields.  This looks a little odd
        since most western languages read from left to right.  In order to make
        the  fields left-justified, add a minus sign (-) in front of the field-
        width:
 
               mp3info -p "%-50f%-31t%-31a%-31l%-4y\n" *.mp3
 
        Now suppose you just want the running time of each MP3  file  specified
        in minutes and seconds.  Simple enough:
 
               mp3info -p "%f: %m:%s\n" *.mp3
 
        You  may  notice  when you do this, however, that leading zeros are not
        displayed in the seconds field (%s).  So for instance,  if  you  had  a
        track  four minutes and two seconds long its running time would be dis‐
        played as ’4:2’ instead of ’4:02’.  In order to tell mp3info to pad  an
        integer  field  with  zeros, you need to use a field width modifier and
        place a zero in front of it.  The following command is the same as  the
        previous  one,  but it specifies that mp3info is to display the seconds
        field with a fixed field-width of two characters and to pad  the  field
        with leading zeros if necessary:
 
               mp3info -p "%f: %m:%02s\n" *.mp3
 
        The  last  trick  we  have  to  show you is the precision specifier for
        floating point variables.  The following command displays the  filename
        and average bit rate for all MP3 files in the current directory.
 
               mp3info -r a -p "%f %r\n" *.mp3
 
        By  default,  the  floating point value of the average bit rate is dis‐
        played with six digits past the decimal point (ex: 175.654332).  If you
        are  like  me, this seems like a bit of overkill.  At most you want one
        or two digits beyond the decimal place displayed.   Or  you  might  not
        want  any.   The  following  command displays the average bit rate with
        first two, then zero digits beyond the decimal point:
 
               mp3info -r a -p "%f %.2r %.0r\n" *.mp3
 
        If you wanted to specify a field width for a floating point value,  you
        could  do  that  by placing the field-width before the decimal point in
        the field modifier.  This command does just that -- specifying an aver‐
        age  bit-rate  field  six  characters wide that will show two digits of
        precision beyond the decimal point:
 
               mp3info -r a -p "%f %6.2r\n" *.mp3
 

BUGS

        There’s no "save and quit" in interactive mode. You must  fill  in  all
        the  fields  (even  if it is with blanks) and let the program finish by
        itself.  CTRL+C does leave MP3info, but the data isn’t saved.
 
        Using space to erase tags in interactive mode does not  work  correctly
        if you then backspace over the deleted text.
 
        The  title, author, album, and comment fields are limited to 30 charac‐
        ters.  This is a limitation of the ID3 1.0 tag format, not MP3Info.  If
        you  specify  the  track  number  (with the -n switch), the ID3 1.0 tag
        becomes a 1.1 tag and the comment field is limited  to  28  characters.
        This  is because the difference between ID3 1.0 and 1.1 is that the tag
        number is stored in the last byte of the  comment  field.   This  trick
        "borrows"  two  bytes  from  the fixed-length comment field effectively
        reducing the maximum comment by two characters.
 
        Genres cannot be specified arbitrarily.  They must be specified from  a
        pre-determined  list (use mp3info -G to see that list).  Again, this is
        a limitation of the ID3 1.0 tag format.
 
        Only ID3 versions 1.0 and 1.1 are supported.  Version 3.0  is  a  "non-
        standard"  standard  that  is much more flexible than the 1.0 standard,
        but has not yet been widely adopted.   The  jury  is  still  out.   See
        www.id3.org for more info.
 

AUTHOR

        Cedric Tefft <cedric@earthling.net>
        printf(3)