Provided by: sox_14.0.1-2build2_i386 bug

NAME

       SoX - Sound eXchange, the Swiss Army knife of audio manipulation

DESCRIPTION

       File  types  that  can be determined by a filename extension are listed
       with their names preceded by a dot.

       File types  that  require  an  external  library,  such  as  ffmpeg  or
       libsndfile,  are marked e.g. ‘(ffmpeg)’. File types that can be handled
       by an external library via its pseudo file type  (currently  libsndfile
       or  ffmpeg)  are  marked  e.g.  ‘(also with -t sndfile)’. This might be
       useful if you have a file that doesn’t work with SoX’s  default  format
       readers  and writers, and there’s an external reader or writer for that
       format.

       .raw (also with -t sndfile)
              Raw (headerless) audio files.  The sample rate, sample size, and
              data  encoding  must be given using command-line format options;
              the number of channels defaults to 1.

       .ub, .sb, .uw, .sw, .ul, .al, .lu, .la, .sl (also with -t sndfile)
              These filename extensions serve as shorthand for identifying the
              format of headerless audio files.  Thus, ub, sb, uw, sw, ul, al,
              lu, la and sl indicate a  file  with  a  single  audio  channel,
              sample  rate of 8000 Hz, and samples encoded as ‘unsigned byte’,
              ‘signed byte’, ‘unsigned word’, ‘signed word’,  ‘μ-law’  (byte),
              ‘A-law’ (byte), inverse bit order ‘μ-law’, inverse bit order ‘A-
              law’,  or  ‘signed  long’  respectively.   Command-line   format
              options  can  also  be given to modify the selected format if it
              does not provide an exact match for a particular file.

              Headerless audio files on a SPARC computer are likely to  be  of
              format  ul;  on a Mac, they’re likely to be ub but with a sample
              rate of 11025 or 22050 Hz.

       .8svx (also with -t sndfile)
              Amiga 8SVX musical instrument description format.

       .aiff, .aif (also with -t sndfile)
              AIFF files used on Apple  IIc/IIgs  and  SGI.   Note:  the  AIFF
              format  supports  only  one  SSND  chunk.   It  does not support
              multiple  audio  chunks,  or   the   8SVX   musical   instrument
              description  format.  AIFF files are multimedia archives and can
              have multiple audio and picture chunks.  You may need a separate
              archiver to work with them.

       .aiffc, .aifc (also with -t sndfile)
              AIFF-C  (not  compressed,  linear),  defined in DAVIC 1.4 Part 9
              Annex B.  This format is referred from ARIB  STD-B24,  which  is
              specified  for  Japanese  data broadcasting.  Any private chunks
              are not supported.

              Note: The input file is currently processed as .aiff.

       alsa   ALSA device driver.  This is  a  pseudo-file  type  and  can  be
              optionally compiled into SoX.  Run

                   sox -h

              to see if you have support for this file type.  When this driver
              is used it allows you to open up a ALSA device and configure  it
              to  use  the same data format as passed in to SoX.  It works for
              both playing and recording  audio  files.   When  playing  audio
              files  it  attempts  to  set  up the ALSA driver to use the same
              format as the input file.  It is suggested  to  always  override
              the  output  values  to use the highest quality format your ALSA
              system can handle.  Example:

                   sox infile -t alsa default

       .amr-nb
              Adaptive Multi Rate - Narrow Band speech codec; a  lossy  format
              used  in  3rd generation mobile telephony and defined in 3GPP TS
              26.071 et al.

              AMR-NB audio has a fixed sampling rate of  8  kHz  and  supports
              encoding  to  the  following  bit-rates  (as  selected by the -C
              option): 0 = 4.75 kbit/s, 1 = 5.15 kbit/s, 2 = 5.9 kbit/s,  3  =
              6.7 kbit/s, 4 = 7.4 kbit/s 5 = 7.95 kbit/s, 6 = 10.2 kbit/s, 7 =
              12.2 kbit/s.

              This format in SoX is optional and requires access  to  external
              libraries.  To see if there is support for this format, enter

                   sox -h

              and look for it under the list: SUPPORTED FILE FORMATS.

       .amr-wb
              Adaptive  Multi  Rate  -  Wide Band speech codec; a lossy format
              used in 3rd generation mobile telephony and defined in  3GPP  TS
              26.171 et al.

              AMR-WB  audio  has  a fixed sampling rate of 16 kHz and supports
              encoding to the following  bit-rates  (as  selected  by  the  -C
              option):  0 = 6.6 kbit/s, 1 = 8.85 kbit/s, 2 = 12.65 kbit/s, 3 =
              14.25 kbit/s, 4 = 15.85 kbit/s 5  =  18.25  kbit/s,  6  =  19.85
              kbit/s, 7 = 23.05 kbit/s, 8 = 23.85 kbit/s.

              This  format  in SoX is optional and requires access to external
              libraries.  To see if there is support for this format  on  your
              system, enter

                   sox -h

              and look for it under the list: SUPPORTED FILE FORMATS.

       ao     libao  device  driver.   This  is  a pseudo-file type and can be
              optionally compiled into SoX.  Run

                   sox -h

              to see if you have support for this file type. It works only for
              playing  audio files. It can play to a wide range of devices and
              sound systems. See its documentation for the full range. For the
              most part, SoX’s use of libao cannot be configured directly; you
              must use libao configuration files.

              The filename specified is used to determine which  libao  plugin
              to  us.  Normally, you should specify "default" as the filename.
              If that doesn’t give the desired behavior then you  can  specify
              the short name for a given plugin (such as pulse for pulse audio
              plugin).

       .au, .snd (also with -t sndfile)
              Sun Microsystems AU files.  There are many types of AU file; DEC
              has  invented  its  own  with  a different magic number and byte
              order.  SoX can read these files but will not write them.   Some
              .au  files  are  known  to  have  invalid  AU headers; these are
              probably original Sun μ-law 8000 Hz files and can be dealt  with
              using the .ul format (see below).

              It  is  possible to override AU file header information with the
              -r and -c options, in which case SoX will  issue  a  warning  to
              that effect.

       auto   This  format  type name exists for backwards compatibility only.
              If given for an input file it will be silently ignored, if given
              for an output file it will cause SoX to exit with an error.

       .avr   Audio  Visual  Research.  The AVR format is produced by a number
              of commercial packages on the Mac.

       .caf (libsndfile)
              Core Audio File format.

       .cdda, .cdr
              ‘Red Book’ Compact Disc  Digital  Audio.   CDDA  has  two  audio
              channels formatted as 16-bit signed integers at a sample rate of
              44.1 kHz.  The number of (stereo) samples in each CDDA track  is
              always  a multiple of 588 which is why it needs its own handler.

       .cvsd, .cvs
              Continuously Variable  Slope  Delta  modulation.   A  headerless
              format  used  to  compress speech audio for applications such as
              voice mail.  This format is  sometimes  used  with  bit-reversed
              samples - the -X format option can be used to set the bit-order.

       .dat   Text Data files.  These files contain a  textual  representation
              of  the  sample  data.   There is one line at the beginning that
              contains the sample rate.  Subsequent lines contain two  numeric
              data items: the time since the beginning of the first sample and
              the sample value.  Values are normalized so that the maximum and
              minimum  are  1  and -1.  This file format can be used to create
              data files for external programs such as FFT analysers or  graph
              routines.   SoX can also convert a file in this format back into
              one of the other file formats.

       .dvms, .vms
              Used in Germany to compress speech  audio  for  voice  mail.   A
              self-describing variant of cvsd.

       .fap (libsndfile)
              See .paf.

       ffmpeg This  is a pseudo-type that forces ffmpeg to be used. The actual
              file type is deduced from the file name (it cannot  be  used  on
              stdio).  This  pseudo-type depends on SoX having been built with
              optional ffmpeg support. It can  read  a  wide  range  of  audio
              files,  not all of which are documented here, and also the audio
              track of many video files (including  AVI,  WMV  and  MPEG).  At
              present only the first audio track of a file can be read.

       .flac (also with -t sndfile)
              Free  Lossless  Audio  CODEC compressed audio.  FLAC is an open,
              patent-free CODEC designed for compressing music.  It is similar
              to  MP3  and  Ogg  Vorbis,  but  lossless, meaning that audio is
              compressed in FLAC without any loss in quality.

              SoX can read native FLAC files (.flac) but not  Ogg  FLAC  files
              (.ogg).  [But see .ogg below for information relating to support
              for Ogg Vorbis files.]

              SoX can write native FLAC files according to a given or  default
              compression level.  8 is the default compression level and gives
              the best (but slowest)  compression;  0  gives  the  least  (but
              fastest)  compression.   The compression level is selected using
              the -C option [see sox(1)] with a whole number from 0 to 8.

              FLAC support in SoX  is  optional  and  requires  optional  FLAC
              libraries.  To see if there is support for FLAC run

                   sox -h

              and  look  for  it  under  the list of supported file formats as
              ‘flac’.

       .fssd  An alias for the .ub format.

       .gsm (also with -t sndfile)
              GSM  06.10  Lossy  Speech  Compression.   A  lossy  format   for
              compressing  speech  which  is  used  in the Global Standard for
              Mobile telecommunications (GSM).  It’s  good  for  its  purpose,
              shrinking  audio  data size, but it will introduce lots of noise
              when a given audio signal is encoded and decoded multiple times.
              This  format  is  used  by  some voice mail applications.  It is
              rather CPU intensive.

              GSM in SoX is optional and requires access to  an  external  GSM
              library.  To see if there is support for GSM run

                   sox -h

              and look for it under the list of supported file formats.

       .hcom  Macintosh  HCOM  files.   These  are (apparently) Mac FSSD files
              with some variant of Huffman  compression.   The  Macintosh  has
              wacky  file  formats  and this format handler apparently doesn’t
              handle all the ones it should.  Mac users will need their  usual
              arsenal  of  file  converters to deal with an HCOM file on other
              systems.

       ircam (also with -t sndfile)
              Another name for .sf.

       .ima (also with -t sndfile)
              A headerless file of IMA ADPCM  audio  data.  IMA  ADPCM  claims
              16-bit  precision packed into only 4 bits, but in fact sounds no
              better than .vox.

       .lpc, .lpc10
              LPC-10 is a compression  scheme  for  speech  developed  in  the
              United   States.   See   http://www.arl.wustl.edu/~jaf/lpc/  for
              details.  There  is  no  associated  file   format,   so   SoX’s
              implementation is headerless.

       .mat, .mat4, .mat5 (libsndfile)
              Matlab 4.2/5.0 (respectively GNU Octave 2.0/2.1) format (.mat is
              the same as .mat4).

       .m3u   A playlist format; contains a list of audio files.  See [1]  for
              details of this format.

       .maud  An  IFF-conforming audio file type, registered by MS MacroSystem
              Computer GmbH, published along with the ‘Toccata’ sound-card  on
              the  Amiga.   Allows  8bit linear, 16bit linear, A-Law, μ-law in
              mono and stereo.

       .mp3, .mp2
              MP3 compressed audio.  MP3 (MPEG Layer 3) is part  of  the  MPEG
              standards  for  audio  and  video  compression.   It  is a lossy
              compression format that achieves  good  compression  rates  with
              little  quality loss.  See also Ogg Vorbis for a similar format.

              MP3 support in SoX is optional and requires access to either  or
              both  the  external  libmad  and libmp3lame libraries. To see if
              there is support for MP3 run

                   sox -h

              and look for it under the list  of  supported  file  formats  as
              ‘mp3’.

       .mp4, .m4a (ffmpeg)
              MP4  compressed  audio.   MP3  (MPEG  4)  is  part  of  the MPEG
              standards for audio and video compression.   See  mp3  for  more
              information.

              MP4  support  in  SoX  is  optional  and  requires access to the
              external ffmpeg libraries.

       .nist (also with -t sndfile)
              See .sph.

       .ogg, .vorbis
              Ogg Vorbis compressed audio.  Ogg Vorbis is a open,  patent-free
              CODEC designed for compressing music and streaming audio.  It is
              a lossy compression format (similar to  MP3,  VQF  &  AAC)  that
              achieves good compression rates with a minimum amount of quality
              loss.  See also MP3 for a similar format.

              SoX can decode all types of Ogg Vorbis files, and can encode  at
              different compression levels/qualities given as a number from -1
              (highest compression/lowest quality) to 10 (lowest  compression,
              highest  quality).   By  default the encoding quality level is 3
              (which gives an encoded rate of approx. 112kbps), but  this  can
              be changed using the -C option (see above) with a number from -1
              to 10; fractional numbers (e.g.  3.6) are also allowed.

              Decoding is somewhat CPU intensive  and  encoding  is  very  CPU
              intensive.

              Ogg  Vorbis  in  SoX is optional and requires access to external
              Ogg Vorbis libraries.  To see if there is support for Ogg Vorbis
              run

                   sox -h

              and  look  for  it  under  the list of supported file formats as
              ‘vorbis’.

       oss    OSS /dev/dsp device driver.  This is a pseudo-file that  can  be
              optionally compiled into SoX.  Run

                   sox -h

              to  see  if  it is supported. When this driver is used it allows
              you to play and record sounds on supported systems. When playing
              audio files it attempts to set up the OSS driver to use the same
              format as the input file. It is suggested to always override the
              output  values to use the highest quality format your OSS system
              can handle. Example:

                   sox infile -t oss -2 -s /dev/dsp

       .paf, .fap (libsndfile)
              Ensoniq PARIS file format (big and little-endian  respectively).

       .pls   A  playlist format; contains a list of audio files.  See [2] for
              details of this format.

              Note: SHOUTcast PLS relies on  wget(1)  and  is  only  partially
              supported:  it’s  necessary  to specify the audio type manually,
              e.g.

                   play -t mp3 "http://a.server/pls?rn=265&file=filename.pls"

              and SoX does not know about alternative  servers  -  hit  Ctrl-C
              twice in quick succession to quit.

       .prc   Psion  Record.  Used  in  Psion  EPOC  PDAs  (Series 5, Revo and
              similar) for System alarms and recordings made by  the  built-in
              Record  application.  When writing, SoX defaults to A-law, which
              is recommended; if you must use ADPCM, then use the  -i  switch.
              The  sound  quality is poor because Psion Record seems to insist
              on frames of 800 samples or fewer, so that the ADPCM  CODEC  has
              to  be  reset  at  every  800  frames, which causes the sound to
              glitch every tenth of a second.

       .pvf (libsndfile)
              Portable Voice Format.

       .sd2 (libsndfile)
              Sound Designer 2 format.

       .sds (libsndfile)
              MIDI Sample Dump Standard.

       .sf (also with -t sndfile)
              IRCAM   SDIF   (Institut   de    Recherche    et    Coordination
              Acoustique/Musique  Sound  Description Interchange Format). Used
              by academic music software such as the CSound package,  and  the
              MixView sound sample editor.

       .sph, .nist (also with -t sndfile)
              SPHERE  (SPeech  HEader  Resources)  is a file format defined by
              NIST (National Institute of Standards  and  Technology)  and  is
              used  with  speech  audio.   SoX  can read these files when they
              contain  μ-law  and  PCM  data.   It  will  ignore  any   header
              information  that  says  the  data  is  compressed using shorten
              compression and will treat the data  as  either  μ-law  or  PCM.
              This  will  allow SoX and the command line shorten program to be
              run together using pipes to encompasses the data and  then  pass
              the result to SoX for processing.

       .smp   Turtle Beach SampleVision files.  SMP files are for use with the
              PC-DOS package SampleVision by  Turtle  Beach  Softworks.   This
              package  is  for  communication  to  several MIDI samplers.  All
              sample rates are supported by the package, although not all  are
              supported by the samplers themselves.  Currently loop points are
              ignored.

       .snd   See .au.

       sndfile
              This is a pseudo-type that forces libsndfile  to  be  used.  For
              writing  files,  the  actual  file  type  is then taken from the
              output file name; for reading them, it is deduced from the file.
              This  pseudo-type depends on SoX having been built with optional
              libsndfile support.

       .sndt  Sndtool  files.   This  format  dates  from  the   MS-DOS   era.
              Bizarrely,  this  file  type  can  also  be used to read Sounder
              files.

       .sou   An alias for the .ub format.

       sunau  Sun /dev/audio device driver.  This is a  pseudo-file  type  and
              can be optionally compiled into SoX.  Run

                   sox -h

              to see if you have support for this file type.  When this driver
              is used it allows you to open  up  a  Sun  /dev/audio  file  and
              configure  it to use the same data type as passed in to SoX.  It
              works for both playing and recording audio files.  When  playing
              audio  files  it  attempts to set up the audio driver to use the
              same format as the  input  file.   It  is  suggested  to  always
              override  the  output  values  to use the highest quality format
              your hardware can handle.  Example:

                   sox infile -t sunau -2 -s /dev/audio

              or

                   sox infile -t sunau -U -c 1 /dev/audio

              for older sun equipment.

       .txw   Yamaha TX-16W sampler.  A file format  from  a  Yamaha  sampling
              keyboard  which  wrote  IBM-PC  format  3.5"  floppies.  Handles
              reading of files which do not have the sample rate field set  to
              one  of  the  expected  by  looking  at  some other bytes in the
              attack/loop length fields,  and  defaulting  to  33 kHz  if  the
              sample rate is still unknown.

       .vms   See .dvms.

       .voc (also with -t sndfile)
              Sound  Blaster  VOC files.  VOC files are multi-part and contain
              silence parts, looping, and different sample rates for different
              chunks.   On  input, the silence parts are filled out, loops are
              rejected, and sample data with a new sample  rate  is  rejected.
              Silence with a different sample rate is generated appropriately.
              On output, silence is not detected, nor  are  impossible  sample
              rates.   Note,  this version now supports playing VOC files with
              multiple blocks and supports playing files containing μ-law  and
              A-law samples.

       .vorbis
              See .ogg.

       .vox (also with -t sndfile)
              A  headerless  file  of  Dialogic/OKI  ADPCM audio data commonly
              comes with the extension  .vox.   This  ADPCM  data  has  12-bit
              precision packed into only 4-bits.

              Note:  some  early  Dialogic  hardware does not always reset the
              ADPCM encoder at the start of each vox file.  This can result in
              clipping and/or DC offset problems when it comes to decoding the
              audio.  Whilst little can be  done  about  the  clipping,  a  DC
              offset  can  be  removed  by passing the decoded audio through a
              high-pass filter, e.g.:

                   sox input.vox output.au highpass 10

       .w64 (libsndfile)
              Sonic Foundry’s 64-bit RIFF/WAV format.

       .wav (also with -t sndfile)
              Microsoft .WAV RIFF files.  This is the native audio file format
              of Windows, and widely used for uncompressed audio.

              Normally  .wav  files  have  all formatting information in their
              headers, and so do not need any format options specified for  an
              input file.  If any are, they will override the file header, and
              you will be warned to this effect.  You had better know what you
              are doing! Output format options will cause a format conversion,
              and the .wav will written appropriately.

              SoX currently can read PCM, μ-law, A-law, MS ADPCM, and IMA  (or
              DVI)  ADPCM.   It  can  write all of these formats including the
              ADPCM encoding.  Big endian versions of RIFF files, called RIFX,
              can  also be read and written.  To write a RIFX file, use the -B
              option with the output file options.

       .wavpcm
              A non-standard variant of .wav.  Some applications cannot read a
              standard  WAV  file header for PCM-encoded data with sample-size
              greater than 16-bits or with more than  two  channels,  but  can
              read  a  non-standard  WAV  header.   It  is  likely  that  such
              applications will eventually be updated to support the  standard
              header,  but  in  the  mean time, this SoX format can be used to
              create files with the non-standard header that should work  with
              these  applications.   (Note  that SoX will automatically detect
              and read WAV files with the non-standard header.)

       .wve   Psion 8-bit A-law.  Used  on  Psion  SIBO  PDAs  (Series  3  and
              similar).

       .xa    Maxis  XA  files.   These  are  16-bit ADPCM audio files used by
              Maxis games.  Writing .xa  files  is  currently  not  supported,
              although adding write support should not be very difficult.

       .xi (libsndfile)
              Fasttracker 2 Extended Instrument format.

SEE ALSO

       sox(1), soxeffect(7), libsox(3), octave(1), soxexam(7), wget(1)

       The SoX web page at http://sox.sourceforge.net

   References
       [1]    Wikipedia, M3U, http://en.wikipedia.org/wiki/M3U

       [2]    Wikipedia, PLS, http://en.wikipedia.org/wiki/PLS_(file_format)

AUTHORS

       Chris  Bagwell  (cbagwell@users.sourceforge.net).   Other  authors  and
       contributors are listed in the AUTHORS file that  is  distributed  with
       the source code.