table of contents
|NA_PLAY(1)||General Commands Manual||NA_PLAY(1)|
na_record — play
waveform files on audio device
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:
- Prints a short summary of usage to standard output.
- 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.
- Number of channels, in an unheadered input file. Again, this can usually be determined from the headers. Default is 1.
- Sampling rate, for an unheadered input file. Default is 16000.
- Byte order, for an unheadered input file. Default is system byte order. Recognized values are: MSB, LSB, native, nonnative.
- Swap bytes in an unheadered input file.
- Sample type for an unheadered input file. Recognized values are: short, mulaw, byte, ascii.
- Select a single channel (starting at 0) for playback. This option plays only the specified channel and discards all others.
- Select a subsection of the file, starting at this time (specified in seconds).
- Select a subsection of the file, ending at this time (specified in seconds).
- Select a subsection of the file, starting at this offset (specified in number of samples).
- Select a subsection of the file, ending at this offset (specified in number of samples).
- Use the specified audio device protocol. The list of supported types
varies between platforms, and can be obtained using the
- 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.
- Treat unheadered input files as 8kHz mu-law data (i.e. audio/basic MIME type)
-qualityhigh | 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.
- Specifies the host to play sound on, when using a network-aware audio protocol (such as NAS)
- Change the gain (volume) of the signal. The argument is a number relative to 1.0, which is the default.
- Be verbose (i.e. print file names when playing)
- Pause for a keystroke between each file.
- Audio protocol to use (as in the
- Command used to play audio when using the audio_command protocol.
- Host to play audio on when using a network audio protocol.
- Playback quality (low or high)
To play the section of foo.wav from 1.5 to 3.2 seconds:
To play samples 3600 to 42000 of channel 1 of bar.wav:
$ na_play -start 1.5 -end 3.2 foo.wav
$ na_play -from 3600 -to 4200 -c 1 foo.wav
The usage information isn't entirely correct. The audio_command protocol generates temporary files insecurely.
|April 4, 2001||Edinburgh Speech Tools|