1SoX(7) Sound eXchange SoX(7)
2
6 SoX - Sound eXchange, the Swiss Army knife of audio manipulation
7
9 This manual describes SoX supported file formats and audio device
10 types; the SoX manual set starts with sox(1).
11 Format types that can SoX can determine by a filename extension are
13 listed with their names preceded by a dot. Format types that are
14 optionally built into SoX are marked `(optional)'.
15 Format types that can be handled by an external library via an optional
17 pseudo file type (currently sndfile) are marked e.g. `(also with -t
18 sndfile)'. This might be useful if you have a file that doesn't work
19 with SoX's default format readers and writers, and there's an external
20 reader or writer for that format.
21 To see if SoX has support for an optional format or device, enter sox
23 -h and look for its name under the list: `AUDIO FILE FORMATS' or `AUDIO
24 DEVICE DRIVERS'.
25 SOX FORMATS & DEVICE DRIVERS
27 .raw (also with -t sndfile), .f32, .f64, .s8, .s16, .s24, .s32,
28 .u8, .u16, .u24, .u32, .ul, .al, .lu, .la
29 Raw (headerless) audio files. For raw, the sample rate and the
30 data encoding must be given using command-line format options;
31 for the other listed types, the sample rate defaults to 8kHz
32 (but may be overridden), and the data encoding is defined by the
33 given suffix. Thus f32 and f64 indicate files encoded as 32 and
34 64-bit (IEEE single and double precision) floating point PCM
35 respectively; s8, s16, s24, and s32 indicate 8, 16, 24, and
36 32-bit signed integer PCM respectively; u8, u16, u24, and u32
37 indicate 8, 16, 24, and 32-bit unsigned integer PCM respec‐
38 tively; ul indicates `μ-law' (8-bit), al indicates `A-law'
39 (8-bit), and lu and la are inverse bit order `μ-law' and inverse
40 bit order `A-law' respectively. For all raw formats, the number
41 of channels defaults to 1 (but may be overridden).
42 Headerless audio files on a SPARC computer are likely to be of
44 format ul; on a Mac, they're likely to be u8 but with a sample
45 rate of 11025 or 22050 Hz.
46 See .ima and .vox for raw ADPCM formats, and .cdda for raw CD
48 digital audio.
49 .f4, .f8, .s1, .s2, .s3, .s4,
51 .u1, .u2, .u3, .u4, .sb, .sw, .sl, .ub, .uw
52 Deprecated aliases for f32, f64, s8, s16, s24, s32,
53 u8, u16, u24, u32, s8, s16, s32, u8, and u16 respectively.
54 .8svx (also with -t sndfile)
56 Amiga 8SVX musical instrument description format.
57 .aiff, .aif (also with -t sndfile)
59 AIFF files as used on old Apple Macs, Apple IIc/IIgs and SGI.
60 SoX's AIFF support does not include multiple audio chunks, or
61 the 8SVX musical instrument description format. AIFF files are
62 multimedia archives and can have multiple audio and picture
63 chunks - you may need a separate archiver to work with them.
64 With Mac OS X, AIFF has been superseded by CAF.
65 .aiffc, .aifc (also with -t sndfile)
67 AIFF-C is a format based on AIFF that was created to allow han‐
68 dling compressed audio. It can also handle little endian uncom‐
69 pressed linear data that is often referred to as sowt encoding.
70 This encoding has also become the defacto format produced by
71 modern Macs as well as iTunes on any platform. AIFF-C files
72 produced by other applications typically have the file extension
73 .aif and require looking at its header to detect the true for‐
74 mat. The sowt encoding is the only encoding that SoX can handle
75 with this format.
76 AIFF-C is defined in DAVIC 1.4 Part 9 Annex B. This format is
78 referred from ARIB STD-B24, which is specified for Japanese data
79 broadcasting. Any private chunks are not supported.
80 alsa (optional)
82 Advanced Linux Sound Architecture device driver; supports both
83 playing and recording audio. ALSA is only used in Linux-based
84 operating systems, though these often support OSS (see below) as
85 well. Examples:
86 sox infile -t alsa
87 sox infile -t alsa default
88 sox infile -t alsa plughw:0,0
89 sox -b 16 -t alsa hw:1 outfile
90 See also play(1), rec(1), and sox(1) -d.
91 .amb Ambisonic B-Format: a specialisation of .wav with between 3 and
93 16 channels of audio for use with an Ambisonic decoder. See
94 http://www.ambisonia.com/Members/mleese/file-format-for-b-format
95 for details. It is up to the user to get the channels together
96 in the right order and at the correct amplitude.
97 .amr-nb (optional)
99 Adaptive Multi Rate - Narrow Band speech codec; a lossy format
100 used in 3rd generation mobile telephony and defined in 3GPP TS
101 26.071 et al.
102 AMR-NB audio has a fixed sampling rate of 8 kHz and supports
104 encoding to the following bit-rates (as selected by the -C
105 option): 0 = 4.75 kbit/s, 1 = 5.15 kbit/s, 2 = 5.9 kbit/s, 3 =
106 6.7 kbit/s, 4 = 7.4 kbit/s 5 = 7.95 kbit/s, 6 = 10.2 kbit/s, 7 =
107 12.2 kbit/s.
108 .amr-wb (optional)
110 Adaptive Multi Rate - Wide Band speech codec; a lossy format
111 used in 3rd generation mobile telephony and defined in 3GPP TS
112 26.171 et al.
113 AMR-WB audio has a fixed sampling rate of 16 kHz and supports
115 encoding to the following bit-rates (as selected by the -C
116 option): 0 = 6.6 kbit/s, 1 = 8.85 kbit/s, 2 = 12.65 kbit/s, 3 =
117 14.25 kbit/s, 4 = 15.85 kbit/s 5 = 18.25 kbit/s, 6 = 19.85
118 kbit/s, 7 = 23.05 kbit/s, 8 = 23.85 kbit/s.
119 ao (optional)
121 Xiph.org's Audio Output device driver; works only for playing
122 audio. It supports a wide range of devices and sound systems -
123 see its documentation for the full range. For the most part,
124 SoX's use of libao cannot be configured directly; instead, libao
125 configuration files must be used.
126 The filename specified is used to determine which libao plugin
128 to use. Normally, you should specify `default' as the filename.
129 If that doesn't give the desired behavior then you can specify
130 the short name for a given plugin (such as pulse for pulse audio
131 plugin). Examples:
132 sox infile -t ao
133 sox infile -t ao default
134 sox infile -t ao pulse
135 See also play(1) and sox(1) -d.
136 .au, .snd (also with -t sndfile)
138 Sun Microsystems AU files. There are many types of AU file; DEC
139 has invented its own with a different magic number and byte
140 order. To write a DEC file, use the -L option with the output
141 file options.
142 Some .au files are known to have invalid AU headers; these are
144 probably original Sun μ-law 8000 Hz files and can be dealt with
145 using the .ul format (see below).
146 It is possible to override AU file header information with the
148 -r and -c options, in which case SoX will issue a warning to
149 that effect.
150 .avr Audio Visual Research format; used by a number of commercial
152 packages on the Mac.
153 .caf (optional)
155 Apple's Core Audio File format.
156 .cdda, .cdr
158 `Red Book' Compact Disc Digital Audio (raw audio). CDDA has two
159 audio channels formatted as 16-bit signed integers (big
160 endian)at a sample rate of 44.1 kHz. The number of (stereo)
161 samples in each CDDA track is always a multiple of 588.
162 coreaudio (optional)
164 Mac OSX CoreAudio device driver: supports both playing and
165 recording audio. If a filename is not specific or if the name
166 is "default" then the default audio device is selected. Any
167 other name will be used to select a specific device. The valid
168 names can be seen in the System Preferences->Sound menu and then
169 under the Output and Input tabs.
170 Examples:
172 sox infile -t coreaudio
173 sox infile -t coreaudio default
174 sox infile -t coreaudio "Internal Speakers"
175 See also play(1), rec(1), and sox(1) -d.
176 .cvsd, .cvs
178 Continuously Variable Slope Delta modulation. A headerless for‐
179 mat used to compress speech audio for applications such as voice
180 mail. This format is sometimes used with bit-reversed samples -
181 the -X format option can be used to set the bit-order.
182 .cvu Continuously Variable Slope Delta modulation (unfiltered). This
184 is an alternative handler for CVSD that is unfiltered but can be
185 used with any bit-rate. E.g.
186 sox infile outfile.cvu rate 28k
187 play -r 28k outfile.cvu sinc -3.4k
188 .dat Text Data files. These files contain a textual representation
190 of the sample data. There is one line at the beginning that
191 contains the sample rate, and one line that contains the number
192 of channels. Subsequent lines contain two or more numeric data
193 intems: the time since the beginning of the first sample and the
194 sample value for each channel.
195 Values are normalized so that the maximum and minimum are 1 and
197 -1. This file format can be used to create data files for
198 external programs such as FFT analysers or graph routines. SoX
199 can also convert a file in this format back into one of the
200 other file formats.
201 Example containing only 2 stereo samples of silence:
203 ; Sample Rate 8012
205 ; Channels 2
206 0 0 0
207 0.00012481278 0 0
208 .dvms, .vms
210 Used in Germany to compress speech audio for voice mail. A
211 self-describing variant of cvsd.
212 .fap (optional)
214 See .paf.
215 .flac (optional; also with -t sndfile)
217 Xiph.org's Free Lossless Audio CODEC compressed audio. FLAC is
218 an open, patent-free CODEC designed for compressing music. It
219 is similar to MP3 and Ogg Vorbis, but lossless, meaning that
220 audio is compressed in FLAC without any loss in quality.
221 SoX can read native FLAC files (.flac) but not Ogg FLAC files
223 (.ogg). [But see .ogg below for information relating to support
224 for Ogg Vorbis files.]
225 SoX can write native FLAC files according to a given or default
227 compression level. 8 is the default compression level and gives
228 the best (but slowest) compression; 0 gives the least (but
229 fastest) compression. The compression level is selected using
230 the -C option [see sox(1)] with a whole number from 0 to 8.
231 .fssd An alias for the .u8 format.
233 .gsrt Grandstream ring-tone files. Whilst this file format can con‐
235 tain A-Law, μ-law, GSM, G.722, G.723, G.726, G.728, or iLBC
236 encoded audio, SoX supports reading and writing only A-Law and
237 μ-law. E.g.
238 sox music.wav -t gsrt ring.bin
239 play ring.bin
240 .gsm (optional; also with -t sndfile)
242 GSM 06.10 Lossy Speech Compression. A lossy format for com‐
243 pressing speech which is used in the Global Standard for Mobile
244 telecommunications (GSM). It's good for its purpose, shrinking
245 audio data size, but it will introduce lots of noise when a
246 given audio signal is encoded and decoded multiple times. This
247 format is used by some voice mail applications. It is rather
248 CPU intensive.
249 .hcom Macintosh HCOM files. These are Mac FSSD files with Huffman
251 compression.
252 .htk Single channel 16-bit PCM format used by HTK, a toolkit for
254 building Hidden Markov Model speech processing tools.
255 .ircam (also with -t sndfile)
257 Another name for .sf.
258 .ima (also with -t sndfile)
260 A headerless file of IMA ADPCM audio data. IMA ADPCM claims
261 16-bit precision packed into only 4 bits, but in fact sounds no
262 better than .vox.
263 .lpc, .lpc10
265 LPC-10 is a compression scheme for speech developed in the
266 United States. See http://www.arl.wustl.edu/~jaf/lpc/ for
267 details. There is no associated file format, so SoX's implemen‐
268 tation is headerless.
269 .mat, .mat4, .mat5 (optional)
271 Matlab 4.2/5.0 (respectively GNU Octave 2.0/2.1) format (.mat is
272 the same as .mat4).
273 .m3u A playlist format; contains a list of audio files. SoX can
275 read, but not write this file format. See [1] for details of
276 this format.
277 .maud An IFF-conforming audio file type, registered by MS MacroSystem
279 Computer GmbH, published along with the `Toccata' sound-card on
280 the Amiga. Allows 8bit linear, 16bit linear, A-Law, μ-law in
281 mono and stereo.
282 .mp3, .mp2 (optional read, optional write)
284 MP3 compressed audio; MP3 (MPEG Layer 3) is a part of the
285 patent-encumbered MPEG standards for audio and video compres‐
286 sion. It is a lossy compression format that achieves good com‐
287 pression rates with little quality loss.
288 Because MP3 is patented, SoX cannot be distributed with MP3 sup‐
290 port without incurring the patent holder's fees. Users who
291 require SoX with MP3 support must currently compile and build
292 SoX with the MP3 libraries (LAME & MAD) from source code, or, in
293 some cases, obtain pre-built dynamically loadable libraries.
294 When reading MP3 files, up to 28 bits of precision is stored
296 although only 16 bits is reported to user. This is to allow
297 default behavior of writing 16 bit output files. A user can
298 specify a higher precision for the output file to prevent loss‐
299 ing this extra information. MP3 output files will use up to 24
300 bits of precision while encoding.
301 MP3 compression parameters can be selected using SoX's -C option
303 as follows (note that the current syntax is subject to change):
304 The primary parameter to the LAME encoder is the bit rate. If
306 the value of the -C value is a positive integer, it's taken as
307 the bitrate in kbps (e.g. if you specify 128, it uses 128 kbps).
308 The second most important parameter is probably "quality"
310 (really performance), which allows balancing encoding speed vs.
311 quality. In LAME, 0 specifies highest quality but is very slow,
312 while 9 selects poor quality, but is fast. (5 is the default and
313 2 is recommended as a good trade-off for high quality encodes.)
314 Because the -C value is a float, the fractional part is used to
316 select quality. 128.2 selects 128 kbps encoding with a quality
317 of 2. There is one problem with this approach. We need 128 to
318 specify 128 kbps encoding with default quality, so 0 means use
319 default. Instead of 0 you have to use .01 (or .99) to specify
320 the highest quality (128.01 or 128.99).
321 LAME uses bitrate to specify a constant bitrate, but higher
323 quality can be achieved using Variable Bit Rate (VBR). VBR qual‐
324 ity (really size) is selected using a number from 0 to 9. Use a
325 value of 0 for high quality, larger files, and 9 for smaller
326 files of lower quality. 4 is the default.
327 In order to squeeze the selection of VBR into the the -C value
329 float we use negative numbers to select VRR. -4.2 would select
330 default VBR encoding (size) with high quality (speed). One spe‐
331 cial case is 0, which is a valid VBR encoding parameter but not
332 a valid bitrate. Compression value of 0 is always treated as a
333 high quality vbr, as a result both -0.2 and 0.2 are treated as
334 highest quality VBR (size) and high quality (speed).
335 See also Ogg Vorbis for a similar format.
337 .nist (also with -t sndfile)
339 See .sph.
340 .ogg, .vorbis (optional)
342 Xiph.org's Ogg Vorbis compressed audio; an open, patent-free
343 CODEC designed for music and streaming audio. It is a lossy
344 compression format (similar to MP3, VQF & AAC) that achieves
345 good compression rates with a minimum amount of quality loss.
346 SoX can decode all types of Ogg Vorbis files, and can encode at
348 different compression levels/qualities given as a number from -1
349 (highest compression/lowest quality) to 10 (lowest compression,
350 highest quality). By default the encoding quality level is 3
351 (which gives an encoded rate of approx. 112kbps), but this can
352 be changed using the -C option (see above) with a number from -1
353 to 10; fractional numbers (e.g. 3.6) are also allowed. Decod‐
354 ing is somewhat CPU intensive and encoding is very CPU inten‐
355 sive.
356 See also .mp3 for a similar format.
358 .opus (optional)
360 Xiph.org's Opus compressed audio; an open, lossy, low-latency
361 codec offering a wide range of compression rates. It uses the
362 Ogg container.
363 SoX can only read Opus files, not write them.
365 oss (optional)
367 Open Sound System /dev/dsp device driver; supports both playing
368 and recording audio. OSS support is available in Unix-like
369 operating systems, sometimes together with alternative sound
370 systems (such as ALSA). Examples:
371 sox infile -t oss
372 sox infile -t oss /dev/dsp
373 sox -b 16 -t oss /dev/dsp outfile
374 See also play(1), rec(1), and sox(1) -d.
375 .paf, .fap (optional)
377 Ensoniq PARIS file format (big and little-endian respectively).
378 .pls A playlist format; contains a list of audio files. SoX can
380 read, but not write this file format. See [2] for details of
381 this format.
382 Note: SoX support for SHOUTcast PLS relies on wget(1) and is
384 only partially supported: it's necessary to specify the audio
385 type manually, e.g.
386 play -t mp3 "http://a.server/pls?rn=265&file=filename.pls"
387 and SoX does not know about alternative servers - hit Ctrl-C
388 twice in quick succession to quit.
389 .prc Psion Record. Used in Psion EPOC PDAs (Series 5, Revo and simi‐
391 lar) for System alarms and recordings made by the built-in
392 Record application. When writing, SoX defaults to A-law, which
393 is recommended; if you must use ADPCM, then use the -e ima-adpcm
394 switch. The sound quality is poor because Psion Record seems to
395 insist on frames of 800 samples or fewer, so that the ADPCM
396 CODEC has to be reset at every 800 frames, which causes the
397 sound to glitch every tenth of a second.
398 pulseaudio (optional)
400 PulseAudio driver; supports both playing and recording of audio.
401 PulseAudio is a cross platform networked sound server. If a
402 file name is specified with this driver, it is ignored. Exam‐
403 ples:
404 sox infile -t pulseaudio
405 sox infile -t pulseaudio default
406 See also play(1), rec(1), and sox(1) -d.
407 .pvf (optional)
409 Portable Voice Format.
410 .sd2 (optional)
412 Sound Designer 2 format.
413 .sds (optional)
415 MIDI Sample Dump Standard.
416 .sf (also with -t sndfile)
418 IRCAM SDIF (Institut de Recherche et Coordination Acous‐
419 tique/Musique Sound Description Interchange Format). Used by
420 academic music software such as the CSound package, and the
421 MixView sound sample editor.
422 .sln Asterisk PBX `signed linear' 8khz, 16-bit signed integer, lit‐
424 tle-endian raw format.
425 .sph, .nist (also with -t sndfile)
427 SPHERE (SPeech HEader Resources) is a file format defined by
428 NIST (National Institute of Standards and Technology) and is
429 used with speech audio. SoX can read these files when they con‐
430 tain μ-law and PCM data. It will ignore any header information
431 that says the data is compressed using shorten compression and
432 will treat the data as either μ-law or PCM. This will allow SoX
433 and the command line shorten program to be run together using
434 pipes to encompasses the data and then pass the result to SoX
435 for processing.
436 .smp Turtle Beach SampleVision files. SMP files are for use with the
438 PC-DOS package SampleVision by Turtle Beach Softworks. This
439 package is for communication to several MIDI samplers. All sam‐
440 ple rates are supported by the package, although not all are
441 supported by the samplers themselves. Currently loop points are
442 ignored.
443 .snd See .au, .sndr and .sndt.
445 sndfile (optional)
447 This is a pseudo-type that forces libsndfile to be used. For
448 writing files, the actual file type is then taken from the out‐
449 put file name; for reading them, it is deduced from the file.
450 sndio (optional)
452 OpenBSD audio device driver; supports both playing and recording
453 audio.
454 sox infile -t sndio
455 See also play(1), rec(1), and sox(1) -d.
456 .sndr Sounder files. An MS-DOS/Windows format from the early '90s.
458 Sounder files usually have the extension `.SND'.
459 .sndt SoundTool files. An MS-DOS/Windows format from the early '90s.
461 SoundTool files usually have the extension `.SND'.
462 .sou An alias for the .u8 raw format.
464 .sox SoX's native uncompressed PCM format, intended for storing (or
466 piping) audio at intermediate processing points (i.e. between
467 SoX invocations). It has much in common with the popular WAV,
468 AIFF, and AU uncompressed PCM formats, but has the following
469 specific characteristics: the PCM samples are always stored as
470 32 bit signed integers, the samples are stored (by default) as
471 `native endian', and the number of samples in the file is
472 recorded as a 64-bit integer. Comments are also supported.
473 See `Special Filenames' in sox(1) for examples of using the .sox
475 format with `pipes'.
476 sunau (optional)
478 Sun /dev/audio device driver; supports both playing and record‐
479 ing audio. For example:
480 sox infile -t sunau /dev/audio
481 or
482 sox infile -t sunau -e mu-law -c 1 /dev/audio
483 for older sun equipment.
484 See also play(1), rec(1), and sox(1) -d.
486 .txw Yamaha TX-16W sampler. A file format from a Yamaha sampling
488 keyboard which wrote IBM-PC format 3.5" floppies. Handles read‐
489 ing of files which do not have the sample rate field set to one
490 of the expected by looking at some other bytes in the
491 attack/loop length fields, and defaulting to 33 kHz if the sam‐
492 ple rate is still unknown.
493 .vms See .dvms.
495 .voc (also with -t sndfile)
497 Sound Blaster VOC files. VOC files are multi-part and contain
498 silence parts, looping, and different sample rates for different
499 chunks. On input, the silence parts are filled out, loops are
500 rejected, and sample data with a new sample rate is rejected.
501 Silence with a different sample rate is generated appropriately.
502 On output, silence is not detected, nor are impossible sample
503 rates. SoX supports reading (but not writing) VOC files with
504 multiple blocks, and files containing μ-law, A-law, and
505 2/3/4-bit ADPCM samples.
506 .vorbis
508 See .ogg.
509 .vox (also with -t sndfile)
511 A headerless file of Dialogic/OKI ADPCM audio data commonly
512 comes with the extension .vox. This ADPCM data has 12-bit pre‐
513 cision packed into only 4-bits.
514 Note: some early Dialogic hardware does not always reset the
516 ADPCM encoder at the start of each vox file. This can result in
517 clipping and/or DC offset problems when it comes to decoding the
518 audio. Whilst little can be done about the clipping, a DC off‐
519 set can be removed by passing the decoded audio through a high-
520 pass filter, e.g.:
521 sox input.vox output.wav highpass 10
522 .w64 (optional)
524 Sonic Foundry's 64-bit RIFF/WAV format.
525 .wav (also with -t sndfile)
527 Microsoft .WAV RIFF files. This is the native audio file format
528 of Windows, and widely used for uncompressed audio.
529 Normally .wav files have all formatting information in their
531 headers, and so do not need any format options specified for an
532 input file. If any are, they will override the file header, and
533 you will be warned to this effect. You had better know what you
534 are doing! Output format options will cause a format conversion,
535 and the .wav will written appropriately.
536 SoX can read and write linear PCM, floating point, μ-law, A-law,
538 MS ADPCM, and IMA (or DVI) ADPCM encoded samples. WAV files can
539 also contain audio encoded in many other ways (not currently
540 supported with SoX) e.g. MP3; in some cases such a file can
541 still be read by SoX by overriding the file type, e.g.
542 play -t mp3 mp3-encoded.wav
543 Big endian versions of RIFF files, called RIFX, are also sup‐
544 ported. To write a RIFX file, use the -B option with the output
545 file options.
546 waveaudio (optional)
548 MS-Windows native audio device driver. Examples:
549 sox infile -t waveaudio
550 sox infile -t waveaudio default
551 sox infile -t waveaudio 1
552 sox infile -t waveaudio "High Definition Audio Device ("
553 If the device name is omitted, -1, or default, then you get the
554 `Microsoft Wave Mapper' device. Wave Mapper means `use the sys‐
555 tem default audio devices'. You can control what `default'
556 means via the OS Control Panel.
557 If the device name given is some other number, you get that
559 audio device by index; so recording with device name 0 would get
560 the first input device (perhaps the microphone), 1 would get the
561 second (perhaps line in), etc. Playback using 0 will get the
562 first output device (usually the only audio device).
563 If the device name given is something other than a number, SoX
565 tries to match it (maximum 31 characters) against the names of
566 the available devices.
567 See also play(1), rec(1), and sox(1) -d.
569 .wavpcm
571 A non-standard, but widely used, variant of .wav. Some applica‐
572 tions cannot read a standard WAV file header for PCM-encoded
573 data with sample-size greater than 16-bits or with more than two
574 channels, but can read a non-standard WAV header. It is likely
575 that such applications will eventually be updated to support the
576 standard header, but in the mean time, this SoX format can be
577 used to create files with the non-standard header that should
578 work with these applications. (Note that SoX will automatically
579 detect and read WAV files with the non-standard header.)
580 The most common use of this file-type is likely to be along the
582 following lines:
583 sox infile.any -t wavpcm -e signed-integer outfile.wav
584 .wv (optional)
586 WavPack lossless audio compression. Note that, when converting
587 .wav to this format and back again, the RIFF header is not nec‐
588 essarily preserved losslessly (though the audio is).
589 .wve (also with -t sndfile)
591 Psion 8-bit A-law. Used on Psion SIBO PDAs (Series 3 and simi‐
592 lar). This format is deprecated in SoX, but will continue to be
593 used in libsndfile.
594 .xa Maxis XA files. These are 16-bit ADPCM audio files used by
596 Maxis games. Writing .xa files is currently not supported,
597 although adding write support should not be very difficult.
598 .xi (optional)
600 Fasttracker 2 Extended Instrument format.
601
603 sox(1), soxi(1), libsox(3), octave(1), wget(1)
604 The SoX web page at http://sox.sourceforge.net
606 SoX scripting examples at http://sox.sourceforge.net/Docs/Scripts
607 References
609 [1] Wikipedia, M3U, http://en.wikipedia.org/wiki/M3U
610 [2] Wikipedia, PLS, http://en.wikipedia.org/wiki/PLS_(file_format)
612
614 Copyright 1998-2013 Chris Bagwell and SoX Contributors.
615 Copyright 1991 Lance Norskog and Sundry Contributors.
616
618 Chris Bagwell (cbagwell@users.sourceforge.net). Other authors and con‐
619 tributors are listed in the ChangeLog file that is distributed with the
620 source code.
621soxformat December 31, 2014 SoX(7)