最近做語音相關的工作，需要錄製一些特定採樣率和格式的語音，使用了sox命令行工具。比較簡單易用，功能還很強大。sox本身是跨平臺的，所以，不同平臺上都可以方便使用。
相應的usage，放在最後。先記錄一下錄製的功能，以下面這種格式爲例
相應的命令行如下：
rec -b 16 -r 16000 -c 1 filename.wav
其中，-b是sample format，-r是採樣率，-c是channels，1是mono，2是stereo
在命令行環境播放，也很簡單。
play filename.wav
詳細的參數信息：
Usage summary: [gopts] [[fopts] infile]... [fopts] outfile [effect [effopt]]...
SPECIAL FILENAMES (infile, outfile):
- Pipe/redirect input/output (stdin/stdout); may need -t
-d, --default-device Use the default audio device (where available)
-n, --null Use the `null' file handler; e.g. with synth effect
-p, --sox-pipe Alias for `-t sox -'
SPECIAL FILENAMES (infile only):
"|program [options] ..." Pipe input from external program (where supported)
http://server/file Use the given URL as input file (where supported)
GLOBAL OPTIONS (gopts) (can be specified at any point before the first effect):
--buffer BYTES Set the size of all processing buffers (default 8192)
--clobber Don't prompt to overwrite output file (default)
--combine concatenate Concatenate all input files (default for sox, rec)
--combine sequence Sequence all input files (default for play)
-D, --no-dither Don't dither automatically
--dft-min NUM Minimum size (log2) for DFT processing (default 10)
--effects-file FILENAME File containing effects and options
-G, --guard Use temporary files to guard against clipping
-h, --help Display version number and usage information
--help-effect NAME Show usage of effect NAME, or NAME=all for all
--help-format NAME Show info on format NAME, or NAME=all for all
--i, --info Behave as soxi(1)
--input-buffer BYTES Override the input buffer size (default: as --buffer)
--no-clobber Prompt to overwrite output file
-m, --combine mix Mix multiple input files (instead of concatenating)
--combine mix-power Mix to equal power (instead of concatenating)
-M, --combine merge Merge multiple input files (instead of concatenating)
--norm Guard (see --guard) & normalise
--play-rate-arg ARG Default `rate' argument for auto-resample with `play'
--plot gnuplot|octave Generate script to plot response of filter effect
-q, --no-show-progress Run in quiet mode; opposite of -S
--replay-gain track|album|off Default: off (sox, rec), track (play)
-R Use default random numbers (same on each run of SoX)
-S, --show-progress Display progress while processing audio data
--single-threaded Disable parallel effects channels processing
--temp DIRECTORY Specify the directory to use for temporary files
-T, --combine multiply Multiply samples of corresponding channels from all
input files (instead of concatenating)
--version Display version number of SoX and exit
-V[LEVEL] Increment or set verbosity level (default 2); levels:
1: failure messages
2: warnings
3: details of processing
4-6: increasing levels of debug messages
FORMAT OPTIONS (fopts):
Input file format options need only be supplied for files that are headerless.
Output files will have the same format as the input file where possible and not
overridden by any of various means including providing output format options.
-v|--volume FACTOR Input file volume adjustment factor (real number)
--ignore-length Ignore input file length given in header; read to EOF
-t|--type FILETYPE File type of audio
-e|--encoding ENCODING Set encoding (ENCODING may be one of signed-integer,
unsigned-integer, floating-point, mu-law, a-law,
ima-adpcm, ms-adpcm, gsm-full-rate)
-b|--bits BITS Encoded sample size in bits
-N|--reverse-nibbles Encoded nibble-order
-X|--reverse-bits Encoded bit-order
--endian little|big|swap Encoded byte-order; swap means opposite to default
-L/-B/-x Short options for the above
-c|--channels CHANNELS Number of channels of audio data; e.g. 2 = stereo
-r|--rate RATE Sample rate of audio
-C|--compression FACTOR Compression factor for output format
--add-comment TEXT Append output file comment
--comment TEXT Specify comment text for the output file
--comment-file FILENAME File containing comment text for the output file
--no-glob Don't `glob' wildcard match the following filename
AUDIO FILE FORMATS: 8svx aif aifc aiff aiffc al amb au avr caf cdda cdr cvs cvsd cvu dat dvms f32 f4 f64 f8 fap flac fssd gsm gsrt hcom htk ima ircam la lpc lpc10 lu mat mat4 mat5 maud mp2 mp3 nist ogg opus paf prc pvf raw s1 s16 s2 s24 s3 s32 s4 s8 sb sd2 sds sf sl sln smp snd sndfile sndr sndt sou sox sph sw txw u1 u16 u2 u24 u3 u32 u4 u8 ub ul uw vms voc vorbis vox w64 wav wavpcm wve xa xi
PLAYLIST FORMATS: m3u pls
AUDIO DEVICE DRIVERS: coreaudio
EFFECTS: allpass band bandpass bandreject bass bend biquad chorus channels compand contrast dcshift deemph delay dither divide+ downsample earwax echo echos equalizer fade fir firfit+ flanger gain highpass hilbert input# loudness lowpass mcompand noiseprof noisered norm oops output# overdrive pad phaser pitch rate remix repeat reverb reverse riaa silence sinc spectrogram speed splice stat stats stretch swap synth tempo treble tremolo trim upsample vad vol
* Deprecated effect + Experimental effect # LibSoX-only effect
EFFECT OPTIONS (effopts): effect dependent; see --help-effect
當然，sox的功能很多，上面介紹的只是自己需要用的一個小功能而已，有需要的可以自行挖掘新的功能。