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7. File conversions.

The section describes various ways that one can convert sound files into different formats.

7.1 SOX (UNIX, PC, Amiga) .

The most versatile tool for converting between various audio formats is SOX ("Sound Exchange"). It can read and write various types of audio files, and optionally applies some special effects (e.g. echo, channel averaging, or rate conversion). SOX recognizes all filename extensions listed in the Overview of File Formats section.

Since source code is available with SOX it is readily portable to any platform you chose.

The source and binaries for selected platforms for SOX is available on the web at If you need a precompiled version for DOS then you may have to settle for the older version 10.

Versions of SOX:

7.2 Sun Sparc.

On Sun Sparcs, starting at SunOS 4.1, a program "raw2audio" is provided by Sun (in /usr/demo/SOUND) which takes a raw u-law file and turns it into a ".au" file by prefixing it with an appropriate header.

7.3 NeXT.

On NeXTs, you can usually rename .au files to .snd and it'll work like a charm, but some .au files lack header info that the NeXT needs. This can be fixed by using sndconvert:

        sndconvert -c 1 -f 1 -s 8012.8210513 -o nextfile.snd

7.4 SGI Indigo, Indigo2, Indy and Personal IRIS.

SGI supports "soundfiler" (in /usr/sbin), a program similar in spirit to SOX but with a GUI. Soundfiler plays aiff, aifc, NeXT/Sun and .wav formats. It can do conversions between any of these formats and to and from raw formats including mulaw. It also does sample rate conversions.

Three shell commands are also provided that give the same functionality: "sfplay", "sfconvert", and SOX"aifcresample" (all in /usr/sbin).

7.5 Amiga.

Mike Cramer's SoundZAP can do no effects except rate change and it only does conversions to IFF, but it is generally much faster than SOX. (Ftp'able from the same directory as amisox above.)

Newer versions of OmniPlay (see Playing on PC's) will also convert to IFF.

7.6 Apple Macintosh

(Thanks to Bill Houle, Bill.Houle@SanDiegoCA.NCR.COM)

Bill Houle sent the following list:

Popular commercial apps are indicated with a [*].  All other programs
mentioned are shareware/freeware available from SUMEX and the various
mirror sites, or check archie for the nearest FTP location.


SoundHack [Tom Erbe,]
  Can read/write Sound Designer II, Audio IFF, IRCAM, DSP Designer and NeXT 
  .snd (or Sun .au); 8-bit uLaw, 8-bit linear, 32-bit floating point and 16-bit
  linear data encoding.  Can read (but not write) raw data files.  Implements
  soundfile convolution, a phase vocoder, a binaural filter and an amplitude 
  analysis & gain change module.

SoundExtractor [Alberto Ricci,]
  Extracts 'snd' resources, AIFF, SoundEdit, VOC, and WAV data from
  practically anything, converting to 'snd' files.

Balthazar [Craig Marciniak, AOL:TemplarDev]
  Converts WAV files to 'snd'.
Brian's Sound Tool [Brian Scott,]
  Converts 'snd' or SoundEdit to WAV.  Can also convert WAV, VOC, AIFF, Amiga
  8SVX and uLaw to 'snd'.

AmigaSndConverter [Povl H. Pederson,]
  Converts Amiga IFF/8SVX to Mac 'snd'.

au<->Mac [Victor J. Heinz,]
  Converts Sun uLaw to Mac 'snd'.
ULAW [Rod Kennedy,]
  Converts 'snd' to Sun uLaw.

UUTool [Bernie Wieser,]
  Primarily a uuencode/decode program, but in true Swiss Army Knife
  fashion can also read/write Sun uLaw, AIFF, and 'snd' files.

ModVoicer [Kip Walker,]
  Converts Amiga MOD voices into SoundEdit files or 'snd' resources.

Music 5 Mac [Simone Bettini,]
  Primarily a Music Synthesis system, but can also convert between 'snd', AIFF,
  and IBM .DAT(?).

See also the section on players -- some players also do conversions.

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