NAME
na_record - record waveform from audio device
SYNOPSIS
na_record [-h] [-f sampling rate] [-audiodevice device] [-time seconds]
[-o file] [-otype type] [-ostype sample type] [-F sample rate]
[-obo MSB | LSB | native] [-oswap] [-p audio device protocol]
DESCRIPTION
na_record records digital audio data from the system's audio input device
and writes it to the specified file. It supports a variety of output
file formats and native audio devices.
The following option flags are recognized:
-h Prints a short summary of usage to standard output.
-f sampling rate
Sets the input sampling rate (in samples per second, i.e.
Hz). Not all devices support all sampling rates, so it may
be desireable to set this separately from the output sampling
rate.
-audiodevice device
Sets the audio device to record from, if supported by the
audio protocol chosen (e.g. /dev/dsp, /dev/audio)
-time seconds
Stops recording after the specified number of seconds.
-o file
Writes sound output to the specified file
-otype type
Specifies the file format to use for output. Supported types
currently include nist, est, dsps, snd, riff, aiff, audlab,
raw, and ascii. The -h flag will show the most accurate list.
The default type is nist.
-F sampling rate
Sets the output sampling rate (again, in samples per second,
i.e. Hz). If this differs from the input sampling rate,
resampling will be done. Defaults to 16000Hz.
-obo byte order
Sets the output byte order. Supported values are MSB, LSB,
and native. Many file formats have their own byte order, or
are byte order independent, so this isn't tremendously useful
except for raw data. The default is the native byte order for
the system audio device.
-oswap
Swap bytes when saving to output.
-ostype sample type
Sets the sample type of the output. Suported values are
short, mulaw, byte, or ascii. Again, this is usually implied
by the file format, so should only be used for raw data. The
default is short (i.e. 16-bit PCM).
-p audio device protocol
Selects an audio device protocol (i.e. type of audio device)
to use. This varies between different installations of
Speech Tools, but defaults to the most 'native' audio device,
usually Open Sound System on Linux and *BSD and /dev/audio on
Solaris.
ENVIRONMENT
NA_PLAY_PROTOCOL
Audio protocol to use (as in the -p flag)
NA_PLAY_HOST
Host to record audio from when using a network audio
protocol.
EXAMPLES
To record five seconds of audio from /dev/dsp1 (on Linux) to foo.wav in
RIFF format at 32kHz:
$ na_record -time 5 -audiodevice /dev/dsp1 -o foo.wav -otype RIFF
-f 32000
To record one second of audio to bar.wav in raw format in 8kHz mu-law:
$ na_record -time 1 -o bar.wav -otype raw -ostype mulaw -f 8000
BUGS
The -time argument only accepts integer values (though the usage message
implies otherwise)
SEE ALSO
na_play(1)