Provided by: speech-tools_2.5.0-13build2_amd64
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 desirable 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. Supported 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)