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)
