sox.txt

visual c++编写关于声音分析的 傅立叶变换．超牛

		 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
		 the ALSA /dev/snd/pcmCxDxp file and configure it to  use  the
		 same  data  format  as	 passed	 in to SoX.  It works for both
		 playing and recording	sound  samples.	  When	playing	 sound
		 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 samples your
		 sound card can handle.	 Example: sox infile  -t  alsa	-w  -s
		 /dev/snd/pcmC0D0p

       .au	 SUN  Microsystems  AU files.  There are apparently many types
		 of .au files; DEC has invented its own with a different magic
		 number	 and word order.  The .au handler can read these files
		 but will not write them.  Some .au files have valid AU	 head-
		 ers and some do not.  The latter are probably original SUN u-
		 law 8000 hz samples.  These can be dealt with using  the  .ul
		 format (see below).

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

       .cdr	 CD-R
		 CD-R files are used in mastering music on Compact Disks.  The
		 audio	data  on a CD-R disk is a raw audio file with a format
		 of stereo 16-bit signed  samples  at  a  44khz	 sample	 rate.
		 There	is a special blocking/padding oddity at the end of the
		 audio file and is why it needs its own handler.

       .cvs	 Continuously Variable Slope Delta modulation
		 Used to compress speech audio for applications such as	 voice
		 mail.

       .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 1.00 and -1.00.  This file format can be used
		 to  create  data files for external programs such as FFT ana-
		 lyzers or graph routines.  SoX can also  convert  a  file  in
		 this format back into one of the other file formats.

       .gsm	 GSM 06.10 Lossy Speech Compression
		 A standard for compressing speech which is used in the Global
		 Standard for Mobil telecommunications (GSM).	Its  good  for
		 its purpose, shrinking audio data size, but it will introduce
		 lots of noise when  a	given  sound  sample  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 your
		 usual arsenal of file converters to deal with	an  HCOM  file
		 under Unix or DOS.

       .maud	 An Amiga format
		 An  IFF-conform sound 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, u-law
		 in mono and stereo.

       .mp3	 MP3 Compressed Audio
		 MP3 audio files come from the MPEG standards  for  audio  and
		 video	compression.  They are a lossy compression format that
		 achieves good compression rates  with	a  minimum  amount  of
		 quality loss.	Also see 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".


       .nul	 Null file handler.  This is a fake file hander that act as if
		 its reading a stream of 0’s from a while or fake writing out-
		 put  to  a  file.   This is not a very useful file handler in
		 most cases.  It might be useful in some scripts were  you  do
		 not  want to read or write from a real file but would like to
		 specify a filename for consistency.

       .ogg	 Ogg Vorbis Compressed Audio.
		 Ogg Vorbis is a open, patent-free  CODEC  designed  for  com-
		 pressing  music  and  streaming audio.	 It is similar to MP3,
		 VQF, AAC, and other lossy formats.  SoX can decode all	 types
		 of Ogg Vorbis files, but can only encode at 128 kbps.	Decod-
		 ing is somewhat CPU intensive and encoding is very CPU inten-
		 sive.
		 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".

       ossdsp	 OSS /dev/dsp 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
		 the  OSS  /dev/dsp file and configure it to use the same data
		 format as passed in to SoX.  It works for  both  playing  and
		 recording   sound  samples.   When  playing  sound  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 out-
		 put values to use the highest quality samples your sound card
		 can handle.  Example: sox infile -t ossdsp -w -s /dev/dsp

       .prc	 Psion record.app
		 Used in some Psion devices for System alarms.	This format is
		 newer then the	 .wve  format  that  is	 used  in  some	 Psion
		 devices.

       .sf	 IRCAM Sound Files.
		 Sound	Files  are used by academic music software such as the
		 CSound package, and the MixView sound sample editor.

       .sph
		 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 u-law and PCM data.  It will ignore any header infor-
		 mation that says the data is compressed  using	 shorten  com-
		 pression  and	will  treat  the  data as either u-law or PCM.
		 This will allow SoX and the command line shorten  program  to
		 be  ran  together using pipes to uncompress 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 them-
		 selves. Currently loop points are ignored.

       .snd
		 Under DOS this file format is the same as the	.sndt  format.
		 Under all other platforms it is the same as the .au format.

       .sndt	 SoundTool files.
		 This is an older DOS file 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  sound  samples.   When  playing  sound  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  out-
		 put  values  to use the highest quality samples your hardware
		 can handle.  Example: sox infile -t sunau -w -s /dev/audio or
		 sox  infile  -t sunau -U -c 1 /dev/audio for older sun equip-
		 ment.

       .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 33kHz if the sample rate  is	 still
		 unknown.

       .vms	 More info to come.
		 Used  to compress speech audio for applications such as voice
		 mail.

       .voc	 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  out-
		 put,  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 u-
		 law and A-law samples.

       vorbis	 See .ogg format.

       vox	 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.

       .wav	 Microsoft .WAV RIFF files.
		 These appear to be very similar to IFF	 files,	 but  not  the
		 same.	 They  are  the	 native	 sound file format of Windows.
		 (Obviously, Windows was of such incredible importance to  the
		 computer industry that it just had to have its own sound file
		 format.)  Normally .wav files have all formatting information
		 in their headers, and so do not need any format options spec-
		 ified 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 appro-
		 priately.  SoX currently can read PCM, ULAW, ALAW, MS	ADPCM,
		 and  IMA  (or	DVI) ADPCM.  It can write all of these formats
		 including (NEW!)  the ADPCM encoding.

       .wve	 Psion 8-bit A-law
		 These are 8-bit A-law 8khz sound  files  used	on  the	 Psion
		 palmtop portable computer.

       .raw	 Raw files (no header).
		 The  sample  rate,  size  (byte,  word,  etc),	 and  encoding
		 (signed, unsigned, etc.)  of the sample file must  be	given.
		 The number of channels defaults to 1.

       .ub, .sb, .uw, .sw, .ul, .al, .lu, .la, .sl
		 These are several suffices which serve as a shorthand for raw
		 files with a given size and encoding.	Thus, ub, sb, uw,  sw,
		 ul,  al, lu, la and sl correspond to "unsigned byte", "signed
		 byte", "unsigned word", "signed word",	 "u-law"  (byte),  "A-
		 law" (byte), inverse bit order "u-law", inverse bit order "A-
		 law", and "signed long".  The sample rate defaults to 8000 hz
		 if not explicitly set, and the number of channels defaults to
		 1.  There are lots of Sparc samples floating around in	 u-law
		 format	 with no header and fixed at a sample rate of 8000 hz.
		 (Certain sound management  software  cheerfully  ignores  the
		 headers.)   Similarly,	 most  Mac sound files are in unsigned
		 byte format with a sample rate of 11025 or 22050 hz.

       .auto	 This is a ‘‘meta-type’’: specifying this type	for  an	 input
		 file  triggers some code that tries to guess the real type by
		 looking for magic words in the header.	 If the type can’t  be
		 guessed,  the program exits with an error message.  The input
		 must be a plain file, not a pipe.  This type  can’t  be  used
		 for output files.

EFFECTS
       Multiple	 effects  may  be applied to the audio data by specifying them
       one after another at the end of the command line.

       avg [ -l | -r | -f | -b | -1 | -2 | -3 | -4 | n,n,...,n ]
		 Reduce the number of channels by averaging  the  samples,  or
		 duplicate  channels to increase the number of channels.  This
		 effect is automatically used when the number of  input	 chan-
		 nels  differ from the number of output channels.  When reduc-
		 ing the number of channels it is possible to manually specify
		 the  avg  effect  and use the -l, -r, -f, -b, -1, -2, -3, -4,
		 options to select only the left,  right,  front,  back	 chan-
		 nel(s)	 or specific channel for the output instead of averag-
		 ing the channels.  The -l, and -r options will	 do  averaging
		 in  quad-channel files so select the exact channel to prevent
		 this.

		 The avg effect can also be invoked with up to 16  double-pre-
		 cision	 numbers,  seperated by commas, which specify the pro-
		 portion (0.0 = 0% and 1.0 = 100%) of each input channel  that
		 is  to	 be  mixed  into  each output channel.	In two-channel
		 mode, 4 numbers  are  given:  l->l,  l->r,  r->l,  and	 r->r,
		 respectively.	In four-channel mode, the first 4 numbers give
		 the proportions for the left-front output  channel,  as  fol-
		 lows:	lf->lf,	 rf->lf,  lb->lf, and rb->rf.  The next 4 give
		 the right-front output in the same order, then left-back  and
		 right-back.

		 It is also possible to use the 16 numbers to expand or reduce
		 the channel count; just specify 0 for unused channels.

		 Finally, certain reduced combination of numbers can be speci-
		 fied for certain input/output channel combinations.


		 In Ch	Out Ch Num Mappings
		 _____	______ ___ _____________________________
		   2	  1	2   l->l, r->l
		   2	  2	1   adjust balance
		   4	  1	4   lf->l, rf->l, lb->l, rb-l
		   4	  2	2   lf->l&rf->r, lb->l&rb->r
		   4	  4	1   adjust balance
		   4	  4	2   front balance, back balance


       band [ -n ] center [ width ]
		 Apply a band-pass filter.  The frequency response drops loga-
		 rithmically around the center frequency.  The width gives the
		 slope	of  the	 drop.	 The frequencies at center + width and
		 center - width will be half  of  their	 original  amplitudes.
		 Band  defaults	 to  a	mode oriented to pitched signals, i.e.
		 voice, singing, or instrumental music.	 The  -n  (for	noise)
		 option uses the alternate mode for un-pitched signals.	 Warn-
		 ing: -n introduces a power-gain of about 11dB in the  filter,
		 so  beware  of output clipping.  Band introduces noise in the
		 shape of the filter, i.e. peaking at the center frequency and
		 settling  around  it.	 See filter for a bandpass effect with
		 steeper shoulders.