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audio(5)

asecure(1m)

aserver(1m)

attributes(1)

send_sound(1)

convert(1)

NAME

convert − convert an audio file

SYNOPSIS

/opt/audio/bin/convert [source_file target_file -sfmt format -dfmt format -ddata data_type -srate rate -drate rate -schannels number -dchannels number]

DESCRIPTION

This command converts audio files from one supported file format, data format, sampling rate, and number of channels to another.  The unconverted file is retained as a source file. 

-sfmt format -dfmt format
are the file formats for the source and destination files. Each format can be one of these:

au Sun file format

snd NeXT file format

wav Microsoft RIFF Waveform file format

u MuLaw format

al ALaw

l16 linear 16-bit format

lo8 offset (unsigned) linear 8-bit format

l8 linear 8-bit format

If you omit -sfmt, convert uses the header or filename extension in the source file.  You can omit -dfmt if you supply a filename extension for the destination file. 

-ddata data_type
is the data type for the destination files. data_type can be one of these:

u MuLaw

al ALaw

l16 linear 16-bit

lo8 offset (unsigned) linear 8-bit data

l8 linear 8-bit data

If you omit -ddata, convert uses an appropriate data type, normally the data type of the source file. 

-srate rate -drate rate
are the number of samples per second for the source and destination file.  Typical sampling rates range from 8 to 11k (for voice quality) to 44,100 (for CD quality). You can use k to indicate thousands.  For example, 8k means 8,000 samples per second. 

If you omit -srate, convert uses a rate defined by the source file header or its filename extension.  For a raw file with no extension, 8,000 is used.   By playing the file, you can determine if 8,000 samples is too fast or too slow. 

If you omit -drate, convert uses a sampling rate appropriate for the destination file format; if possible, it matches the sampling rate of the source file. 

-schannels number -dchannels number
are the number of channels in the source and destination files. Use 1 for mono; 2 for stereo. If -schannels is omitted, convert uses the information in the header; for raw data files, it uses mono. 

If -dchannels is omitted, convert matches what was used for the source file (through the header or -schannels option); for raw data files, it uses mono. 

EXAMPLES

Convert a raw data file to a headered file. 

cd /opt/audio/bin
convert  beep.l16  beep.au

Convert a raw data file to a headered file when the source has no extension, was sampled at 11,025 per second, and has stereo data. 

cd /opt/audio/bin
convert  beep  beep.au -sfmt l16 -srate 11025 -schannels 2

To save disk space, convert an audio file with CD quality sound to voice quality sound. 

cd /opt/audio/bin
convert idea.au  idea2.au -ddata u -drate 8k -dchannels 1

AUTHOR

convert was developed by HP.  Sun is a trademark of Sun MicroSystems, Inc.
NeXT is a trademark of NeXT Computers, Inc.
Microsoft is a trademark of Microsoft Corporation.

SEE ALSO

audio(5), asecure(1m), aserver(1m), attributes(1), send_sound(1). 

Using the Audio Developer’s Kit

Hewlett-Packard Company  —  HP-UX Release 10.20:  July 1996

Typewritten Software • bear@typewritten.org • Edmonds, WA 98026