manpagez: man pages & more
man flac(1)
Home | html | info | man
flac(1)                                                                flac(1)


       flac - Free Lossless Audio Codec


       flac  [ OPTIONS ] [ infile.wav | infile.rf64 | infile.aiff | infile.raw
       | infile.flac | infile.oga | infile.ogg | - ... ]

       flac [ -d | --decode | -t | --test | -a | --analyze ]  [  OPTIONS  ]  [
       infile.flac | infile.oga | infile.ogg | - ... ]


       flac is a command-line tool for encoding, decoding, testing and analyz-
       ing FLAC streams.


       A summary of options is included below.  For  a  complete  description,
       see the HTML documentation.

       -v, --version
              Show the flac version number

       -h, --help
              Show basic usage and a list of all options

       -H, --explain
              Show detailed explanation of usage and all options

       -d, --decode
              Decode (the default behavior is to encode)

       -t, --test
              Test  a  flac encoded file (same as -d except no decoded file is

       -a, --analyze
              Analyze a FLAC encoded file (same as -d except an analysis  file
              is written)

       -c, --stdout
              Write output to stdout

       -s, --silent
              Silent  mode  (do  not write runtime encode/decode statistics to

              Do not print anything of any kind, including warnings or errors.
              The  exit code will be the only way to determine successful com-

              Do not convert tags from local charset to UTF-8.  This is useful
              for  scripts, and setting tags in situations where the locale is
              wrong.  This option must appear before any tag options!

       -w, --warnings-as-errors
              Treat all warnings as errors (which cause flac to terminate with
              a non-zero exit code).

       -f, --force
              Force  overwriting of output files.  By default, flac warns that
              the output file already exists and continues to the next file.

       -o filename, --output-name=filename
              Force the output file name (usually flac just changes the exten-
              sion).   May  only be used when encoding a single file.  May not
              be used in conjunction with --output-prefix.

              Prefix each output file name with the given string.  This can be
              useful  for encoding or decoding files to a different directory.
              Make sure if your string is a path name  that  it  ends  with  a
              trailing `/' (slash).

              Automatically delete the input file after a successful encode or
              decode.  If there was an error (including a  verify  error)  the
              input file is left intact.

              Output  files  have  their  timestamps/permissions  set to match
              those of their inputs (this is default).  Use --no-preserve-mod-
              time to make output files have the current time and default per-

              If encoding, save WAVE, RF64, or AIFF non-audio chunks  in  FLAC
              metadata.   If decoding, restore any saved non-audio chunks from
              FLAC metadata when writing the decoded file.   Foreign  metadata
              cannot be transcoded, e.g. WAVE chunks saved in a FLAC file can-
              not be restored when decoding to AIFF.  Input and output must be
              regular files (not stdin or stdout).

              Skip  over the first number of samples of the input.  This works
              for both encoding and decoding, but not testing.   The  alterna-
              tive  form can be used to specify minutes, seconds, and
              fractions of a second.

              Stop at the given sample number for each input file.  This works
              for both encoding and decoding, but not testing.  The given sam-
              ple number is not included in the decoded output.  The  alterna-
              tive  form can be used to specify minutes, seconds, and
              fractions of a second.  If a `+' (plus) sign is  at  the  begin-
              ning,  the  --until point is relative to the --skip point.  If a
              `-' (minus) sign is at the beginning, the --until point is rela-
              tive to end of the audio.

       --ogg  When  encoding, generate Ogg FLAC output instead of native FLAC.
              Ogg FLAC streams are FLAC streams wrapped in  an  Ogg  transport
              layer.   The  resulting file should have an '.oga' extension and
              will still be decodable by flac.

              When decoding, force the input to be treated as Ogg FLAC.   This
              is useful when piping input from stdin or when the filename does
              not end in '.oga' or '.ogg'.

              When used with --ogg, specifies the serial number to use for the
              first  Ogg FLAC stream, which is then incremented for each addi-
              tional stream.  When encoding and no  serial  number  is  given,
              flac  uses a random number for the first stream, then increments
              it for each additional stream.  When decoding and no  number  is
              given, flac uses the serial number of the first page.

              Includes  the  residual  signal in the analysis file.  This will
              make the file very big, much larger than even the decoded  file.

              Generates a gnuplot file for every subframe; each file will con-
              tain the residual distribution of the subframe.  This will  cre-
              ate a lot of files.

              Set  the beginning and ending cuepoints to decode.  The optional
              first #.# is the track and index point at  which  decoding  will
              start; the default is the beginning of the stream.  The optional
              second #.# is the track and index point at which  decoding  will
              end; the default is the end of the stream.  If the cuepoint does
              not exist, the closest one before it (for the  start  point)  or
              after  it  (for  the  end  point)  will be used.  If those don't
              exist, the start of the stream (for the start point) or  end  of
              the  stream (for the end point) will be used.  The cuepoints are
              merely translated into sample numbers then used  as  --skip  and
              --until.   A  CD  track  can  always  be  cued  by, for example,
              --cue=9.1-10.1 for track 9, even if the CD has no 10th track.

       -F, --decode-through-errors
              By default flac stops decoding with an  error  and  removes  the
              partially decoded file if it encounters a bitstream error.  With
              -F, errors are still printed but flac will continue decoding  to
              completion.   Note that errors may cause the decoded audio to be
              missing some samples or have silent sections.

              Applies ReplayGain values while decoding.


              The  equals  sign  and <specification> is optional.  If omitted,
              the default is 0aLn1.

              The <specification> is a shorthand notation for  describing  how
              to  apply  ReplayGain.  All components are optional but order is
              important.  '[]' means 'optional'.  '|' means 'or'.  '{}'  means
              required.  The format is:


              preamp A  floating  point  number  in  dB.  This is added to the
                     existing gain value.

              a|t    Specify 'a' to use the album gain,  or  't'  to  use  the
                     track gain.  If tags for the preferred kind (album/track)
                     do not exist but tags for  the  other  (track/album)  do,
                     those will be used instead.

              l|L    Specify 'l' to peak-limit the output, so that the Replay-
                     Gain peak value is full-scale.  Specify 'L' to use a  6dB
                     hard  limiter  that  kicks  in when the signal approaches

                     Specify the amount of noise shaping.  ReplayGain  synthe-
                     sis  happens  in  floating  point; the result is dithered
                     before converting back  to  integer.   This  quantization
                     adds  noise.  Noise shaping tries to move the noise where
                     you won't hear it as much.  0 means no noise  shaping,  1
                     means 'low', 2 means 'medium', 3 means 'high'.

       For example, the default of 0aLn1 means 0dB preamp, use album gain, 6dB
       hard limit, low noise shaping.

       --apply-replaygain-which-is-not-lossless=3 means 3dB preamp, use  album
       gain, no limiting, no noise shaping.

       flac  uses  the  ReplayGain tags for the calculation.  If a stream does
       not have the required tags or they can't be parsed, decoding will  con-
       tinue with a warning, and no ReplayGain is applied to that stream.

       -V, --verify
              Verify a correct encoding by decoding the output in parallel and
              comparing to the original

       --lax  Allow encoder to generate non-Subset files.  The resulting  FLAC
              file may not be streamable or might have trouble being played in
              all players (especially hardware devices), so  you  should  only
              use  this  option  in  combination  with custom encoding options
              meant for archival.

              Calculate ReplayGain values and store them as FLAC tags, similar
              to  vorbisgain.   Title  gains/peaks  will  be computed for each
              input file, and an album gain/peak  will  be  computed  for  all
              files.   All  input  files must have the same resolution, sample
              rate, and number of channels.  Only mono and  stereo  files  are
              allowed,  and  the sample rate must be one of 8, 11.025, 12, 16,
              22.05, 24, 32, 44.1, or 48 kHz.  Also note that this option  may
              leave  a few extra bytes in a PADDING block as the exact size of
              the tags is not known until all files are processed.  Note  that
              this  option  cannot  be  used  when encoding to standard output

              Import the given cuesheet file and store it in a CUESHEET  meta-
              data block.  This option may only be used when encoding a single
              file.  A seekpoint will be added for each  index  point  in  the
              cuesheet  to the SEEKTABLE unless --no-cued-seekpoints is speci-

              Import a picture and store it in a PICTURE metadata block.  More
              than  one --picture command can be specified.  Either a filename
              for the picture file or a more complete specification  form  can
              be  used.   The  SPECIFICATION is a string whose parts are sepa-
              rated by | (pipe) characters.  Some parts may be left  empty  to
              invoke   default   values.    FILENAME  is  just  shorthand  for
              "||||FILENAME".  The format of SPECIFICATION is


              TYPE is optional; it is a number from one of:

              0: Other

              1: 32x32 pixels 'file icon' (PNG only)

              2: Other file icon

              3: Cover (front)

              4: Cover (back)

              5: Leaflet page

              6: Media (e.g. label side of CD)

              7: Lead artist/lead performer/soloist

              8: Artist/performer

              9: Conductor

              10: Band/Orchestra

              11: Composer

              12: Lyricist/text writer

              13: Recording Location

              14: During recording

              15: During performance

              16: Movie/video screen capture

              17: A bright coloured fish

              18: Illustration

              19: Band/artist logotype

              20: Publisher/Studio logotype

              The  default  is 3 (front cover).  There may only be one picture
              each of type 1 and 2 in a file.

              MIME-TYPE is optional; if left blank, it will be  detected  from
              the  file.   For  best  compatibility with players, use pictures
              with MIME type image/jpeg or image/png.  The MIME type can  also
              be  -->  to mean that FILE is actually a URL to an image, though
              this use is discouraged.

              DESCRIPTION is optional; the default is an empty string.

              The next part specfies the resolution and color information.  If
              the  MIME-TYPE  is  image/jpeg, image/png, or image/gif, you can
              usually leave this empty and they can be detected from the file.
              Otherwise,  you must specify the width in pixels, height in pix-
              els, and color  depth  in  bits-per-pixel.   If  the  image  has
              indexed  colors  you  should  also  specify the number of colors
              used.  When manually specified, it is not  checked  against  the
              file for accuracy.

              FILE  is the path to the picture file to be imported, or the URL
              if MIME type is -->

              For example, "|image/jpeg|||../cover.jpg" will  embed  the  JPEG
              file  at ../cover.jpg, defaulting to type 3 (front cover) and an
              empty description.   The  resolution  and  color  info  will  be
              retrieved from the file itself.

              The                                                specification
              "4|-->|CD|320x300x24/173|http://blah.blah/backcover.tiff"   will
              embed the given URL, with type 4 (back cover), description "CD",
              and a manually specified resolution  of  320x300,  24  bits-per-
              pixel, and 173 colors.  The file at the URL will not be fetched;
              the URL itself is stored in the PICTURE metadata block.

              Align encoding of multiple CD format files on sector boundaries.
              See the HTML documentation for more information.  This option is
              DEPRECATED and may not exist in future versions of flac.

              When encoding to flac, ignore the file size headers in  WAV  and
              AIFF files to attempt to work around problems with over-sized or
              malformed files.

              WAV and AIFF files both have an unsigned 32 bit numbers  in  the
              file  header which specifes the length of audio data. Since this
              number is unsigned 32 bits, that limits the size of a valid file
              to  being just over 4 Gigabytes. Files larger than this are mal-
              formed, but should be read correctly using this option.

       -S {#|X|#x|#s}, --seekpoint={#|X|#x|#s}
              Include a point or points in a SEEKTABLE.  Using #, a seek point
              at that sample number is added.  Using X, a placeholder point is
              added at the end of a the table.  Using #x, # evenly spaced seek
              points  will be added, the first being at sample 0.  Using #s, a
              seekpoint will be added every # seconds (# does not have to be a
              whole  number;  it can be, for example, 9.5, meaning a seekpoint
              every 9.5 seconds).  You may use many -S options; the  resulting
              SEEKTABLE  will  be  the  unique-ified union of all such values.
              With no -S options, flac defaults to '-S 10s'.   Use  --no-seek-
              table for no SEEKTABLE.  Note: '-S #x' and '-S #s' will not work
              if the encoder can't determine the input size  before  starting.
              Note:  if you use '-S #' and # is >= samples in the input, there
              will be either no seek point  entered  (if  the  input  size  is
              determinable  before encoding starts) or a placeholder point (if
              input size is not determinable).

       -P #, --padding=#
              Tell the encoder to write a PADDING metadata block of the  given
              length (in bytes) after the STREAMINFO block.  This is useful if
              you plan to tag  the  file  later  with  an  APPLICATION  block;
              instead  of  having  to  rewrite  the  entire file later just to
              insert your block, you  can  write  directly  over  the  PADDING
              block.   Note that the total length of the PADDING block will be
              4 bytes longer than the length given because of the  4  metadata
              block header bytes.  You can force no PADDING block at all to be
              written with --no-padding.  The encoder writes a  PADDING  block
              of  8192  bytes  by  default  (or 65536 bytes if the input audio
              stream is more that 20 minutes long).

              Add a FLAC tag.  The comment must adhere to the  Vorbis  comment
              spec;  i.e. the FIELD must contain only legal characters, termi-
              nated by an 'equals' sign.  Make sure to quote  the  comment  if
              necessary.  This option may appear more than once to add several
              comments.  NOTE: all tags will be added to all encoded files.

              Like --tag, except FILENAME is a file  whose  contents  will  be
              read  verbatim  to set the tag value.  The contents will be con-
              verted to UTF-8 from the local charset.  This  can  be  used  to
              store    a    cuesheet    in    a    tag    (e.g.    --tag-from-
              file="CUESHEET=image.cue").  Do not try to store binary data  in
              tag fields!  Use APPLICATION blocks for that.

       -b #, --blocksize=#
              Specify  the block size in samples.  Subset streams must use one
              of 192, 576, 1152, 2304, 4608, 256, 512, 1024, 2048,  4096  (and
              8192 or 16384 if the sample rate is >48kHz).

       -m, --mid-side
              Try mid-side coding for each frame (stereo input only)

       -M, --adaptive-mid-side
              Adaptive mid-side coding for all frames (stereo input only)

       -0..-8, --compression-level-0..--compression-level-8
              Fastest compression..highest compression (default is -5).  These
              are synonyms for other options:

              -0, --compression-level-0
                     Synonymous with -l 0 -b 1152 -r 3 --no-mid-side

              -1, --compression-level-1
                     Synonymous with -l 0 -b 1152 -M -r 3

              -2, --compression-level-2
                     Synonymous with -l 0 -b 1152 -m -r 3

              -3, --compression-level-3
                     Synonymous with -l 6 -b 4096 -r 4 --no-mid-side

              -4, --compression-level-4
                     Synonymous with -l 8 -b 4096 -M -r 4

              -5, --compression-level-5
                     Synonymous with -l 8 -b 4096 -m -r 5

              -6, --compression-level-6
                     Synonymous with -l 8 -b 4096 -m -r  6  -A  tukey(0.5)  -A

              -7, --compression-level-7
                     Synonymous  with  -l  12 -b 4096 -m -r 6 -A tukey(0.5) -A

              -8, --compression-level-8
                     Synonymous with -l 12 -b 4096 -m -r 6  -A  tukey(0.5)  -A
                     partial_tukey(2) -A punchout_tukey(3)

       --fast Fastest compression.  Currently synonymous with -0.

       --best Highest compression.  Currently synonymous with -8.

       -e, --exhaustive-model-search
              Do exhaustive model search (expensive!)

       -A function, --apodization=function
              Window  audio  data  with  given  the apodization function.  The
              functions are: bartlett, bartlett_hann, blackman,  blackman_har-
              ris_4term_92db,  connes,  flattop, gauss(STDDEV), hamming, hann,
              kaiser_bessel,  nuttall,  rectangle,  triangle,  tukey(P),  par-
              tial_tukey(n[/ov[/P]]), punchout_tukey(n[/ov[/P]]), welch.

              For  gauss(STDDEV),  STDDEV  is  the  standard deviation (0<STD-

              For tukey(P), P specifies the fraction of  the  window  that  is
              tapered  (0<=P<=1; P=0 corresponds to "rectangle" and P=1 corre-
              sponds to "hann").

              For partial_tukey(n) and punchout_tukey(n), n apodization  func-
              tions  are added that span different parts of each block. Values
              of 2 to 6 seem to yield sane results. If necessary,  an  overlap
              can  be  specified,  as  can be the taper parameter, for example
              partial_tukey(2/0.2) or partial_tukey(2/0.2/0.5). ov  should  be
              smaller than 1 and can be negative.

              Please  note  that  P,  STDDEV  and ov are locale specific, so a
              comma as decimal separator might be required instead of a dot.

              More than one -A option (up to 32) may be  used.   Any  function
              that  is specified erroneously is silently dropped.  The encoder
              chooses suitable defaults in the absence of any -A options;  any
              -A option specified replaces the default(s).

              When  more  than  one function is specified, then for every sub-
              frame the encoder will try each of them  separately  and  choose
              the  window  that  results  in the smallest compressed subframe.
              Multiple functions can greatly increase the encoding time.

       -l #, --max-lpc-order=#
              Specifies the maximum LPC order. This number must be <= 32.  For
              Subset  streams,  it must be <=12 if the sample rate is <=48kHz.
              If 0, the encoder will not attempt  generic  linear  prediction,
              and  use only fixed predictors. Using fixed predictors is faster
              but usually results in files being 5-10% larger.

       -p, --qlp-coeff-precision-search
              Do exhaustive search  of  LP  coefficient  quantization  (expen-
              sive!).  Overrides -q; does nothing if using -l 0

       -q #, --qlp-coeff-precision=#
              Precision  of  the quantized linear-predictor coefficients, 0 =>
              let encoder decide (min is 5, default is 0)

       -r [#,]#, --rice-partition-order=[#,]#
              Set the [min,]max residual partition order (0..15). min defaults
              to 0 if unspecified.  Default is -r 5.

              Set the byte order for samples

              Set number of channels.

              Set bits per sample.

              Set sample rate (in Hz).

              Set the sign of samples (the default is signed).

              Specify the size of the raw input in bytes.  If you are encoding
              raw samples from stdin, you must set this option in order to  be
              able  to  use --skip, --until, --cuesheet, or other options that
              need to know the size of the  input  beforehand.   If  the  size
              given  is  greater  than  what is found in the input stream, the
              encoder will complain about an unexpected end-of-file.   If  the
              size given is less, samples will be truncated.

              Force  input  (when  encoding)  or  output (when decoding) to be
              treated as raw samples (even if filename ends in .wav).

              Force the decoder to output AIFF format.   This  option  is  not
              needed  if  the output filename (as set by -o) ends with .aif or
              .aiff.  Also, this option has  no  effect  when  encoding  since
              input AIFF is auto-detected.

              Force  the  decoder  to  output RF64 format.  This option is not
              needed if the output filename (as set by -o)  ends  with  .rf64.
              Also,  this  option has no effect when encoding since input RF64
              is auto-detected.

              Force the decoder to output Wave64 format.  This option  is  not
              needed  if  the  output  filename (as set by -o) ends with .w64.
              Also, this option has no effect when encoding since input Wave64
              is auto-detected.





















              These flags can be used to invert the sense of the corresponding
              normal option.



       The programs are documented fully by HTML format documentation,  avail-
       able in /usr/share/doc/libflac-doc/html on Debian GNU/Linux systems.


       This   manual   page   was   initially   written   by   Matt  Zimmerman
       <> for the Debian GNU/Linux system (but may  be  used  by
       others). It has been kept up-to-date by the Foundation.

                                  2013/09/18                           flac(1)

flac 1.3.2 - Generated Sat Jan 7 14:11:25 CST 2017
© 2000-2021
Individual documents may contain additional copyright information.