NAME
na_record - play waveform files on audio device
SYNOPSIS
na_play [-h] [-itype type] [-n channels] [-f sample rate]
[-ibo byteorder] [-iswap] [-istype type] [-c channel]
[-start time] [-end time] [-from sample] [-to sample]
[-p protocol] [-command command] [-basic] [-quality high | low]
[-server host] [-scale scale] [-v] [-wait] input files ...
DESCRIPTION
na_play plays digital audio data to the system's audio input device from
the specified file(s). It supports a variety of file formats and native
audio devices.
The following option flags are recognized:
-h Prints a short summary of usage to standard output.
-itype type
Input file type. Usually, the input type can be determined
from the file's headers, so this option is not required
except for raw (unheadered) data. Supported types are
currently: nist, est, esps, snd, riff, aiff, audlab, raw,
ascii.
-n channels
Number of channels, in an unheadered input file. Again, this
can usually be determined from the headers. Default is 1.
-f sampling rate
Sampling rate, for an unheadered input file. Default is
16000.
-ibo byte order
Byte order, for an unheadered input file. Default is system
byte order. Recognized values are: MSB, LSB, native,
nonnative.
-iswap
Swap bytes in an unheadered input file.
-istype type
Sample type for an unheadered input file. Recognized values
are: short, mulaw, byte, ascii.
-c channel
Select a single channel (starting at 0) for playback. This
option plays only the specified channel and discards all
others.
-start time
Select a subsection of the file, starting at this time
(specified in seconds).
-end time
Select a subsection of the file, ending at this time
(specified in seconds).
-from sample
Select a subsection of the file, starting at this offset
(specified in number of samples).
-to sample
Select a subsection of the file, ending at this offset
(specified in number of samples).
-p protocol
Use the specified audio device protocol. The list of
supported types varies between platforms, and can be obtained
using the -h flag.
-command command
If the "audio_command" protocol is specified, this argument
must be given to select the command used to play the
waveform. A temporary file is created and passed in the
environment variable FILE. The sample rate is passed in the
environment varialbe SR.
-basic
Treat unheadered input files as 8kHz mu-law data (i.e.
audio/basic MIME type)
-quality high | low
Select the quality of output. "high" will ensure that proper
resampling is used. "low" means to play as fast as possible
with a minimum of processor time.
-server host
Specifies the host to play sound on, when using a network-
aware audio protocol (such as NAS)
-scale scale
Change the gain (volume) of the signal. The argument is a
number relative to 1.0, which is the default.
-v Be verbose (i.e. print file names when playing)
-wait
Pause for a keystroke between each file.
ENVIRONMENT
NA_PLAY_PROTOCOL
Audio protocol to use (as in the -p flag)
NA_PLAY_COMMAND
Command used to play audio when using the audio_command
protocol.
NA_PLAY_HOST
Host to play audio on when using a network audio protocol.
NA_PLAY_QUALITY
Playback quality (low or high)
EXAMPLES
To play the section of foo.wav from 1.5 to 3.2 seconds:
$ na_play -start 1.5 -end 3.2 foo.wav
To play samples 3600 to 42000 of channel 1 of bar.wav:
$ na_play -from 3600 -to 4200 -c 1 foo.wav
BUGS
The usage information isn't entirely correct. The audio_command protocol
generates temporary files insecurely.
SEE ALSO
na_record(1)