Display Signal / Legacy Software / Software / Home
This is a graphical user interface tool for viewing signal waveforms. The tool provides spectrograms and energy plots, signal selection, and audio playback capabilities. The tool is a single channel version which is specifically designed for quick access to multiple files from a single speaker (mono). It is written partly in object-oriented C++ (using GNU's gcc compiler) which is interfaced to Tcl-Tk (v8.0) utilities.

To download the Display Signal Tool click here. Also please feel free to send us comments or suggestions regarding the tool.

The Display Signal Tool:

Display Signal Tool

The main features include
  • displays signal waveforms
  • displays spectrograms
  • displays energy plots
  • zoom in/out on the displays
  • ability to set time marks
  • ability to quickly switch between audio files from the listbox
  • plays audio on mono channelsa
  • set user-defined configurations
The energy plot display:

Energy plot

The energy plot features include
  • zoom in/out on the energy plot
  • ability to set the canvas size
  • ability to change the amplitude
  • ability to set the frame length
  • ability to set the window length
  • ability to set the RMS scale factor
  • ability to set the preemphasis coefficient
  • ability to set the window function
The signal plot display:

Signal plot

The signal plot features include
  • zoom in/out on the signal plot
  • ability to change the amplitude
  • ability to change the volume
  • ability to set the audio device and server
The spectrogram display:

Spectrogram

The spectrogram features include
  • zoom in/out on the spectrogram
  • ability to change brightness
  • ability to change the contrast
  • ability to set the preemphasis coefficient
  • ability to set the window function
The Display Signal Tool currently supports only 16 bit single channel linear data (RAW). In order to use the Tool with other types of data you will need to use the NIST SPHERE tools to convert your data to RAW format.

There are two ways to load a audio file using the Display Signal Tool.
  1. The first way is by passing the audio files or a list (containing multiple audio file path name) via the command line. The following are examples of how to load multiple audio files as well as a list via the command line:
    • isip_display_signal foo1.raw foo2.raw (to load multiple files)
    • isip_display_signal foo.list (to load all files in the list)
  2. The second way is by clicking on the Load button on the main screen and then selecting a file or a list via the Browsefacility.
Examples of audio files and a list file can be found under the data directory of the Tool.

There are several options that are available for using the display and audio facilities. These options are accessible by clicking on the Config button on the main screen.

Spectrogram

In the first section under Audio-Related Parameters you have the option of setting the audio device (sparc, dat, ncd, x86) to you system. You can also select the audio server (speaker, headphone, line) from the options offered.

In the second section under Energy Plot Parameters you have the option of changing the energy plot parameters. The options include changing the frame length, window length and the RMS scale factor of the energy plot. You can even enlarge or diminish the size of the energy plot canvas by setting the Canvas Size option to your preference.

In the third section under Spectrogram Parameters you have the option of setting the brightness and contrast of the spectrogram to any specific value instead of using the slider bars on the main screen.

Finally in the last section under Miscellaneous you have the option of preemphasizing the data for the energy plot and spectrogram. You can either set the preemphasis on or off depending on your preference. You can also set the preemphasis coefficient to any desired value. In this section you also have the option of windowing the data using the standard window functions like Hamming, Hanning, rectangular, Bartlett and Blackman.

Other display options include having the ability to zoom into a section of the signal using the key bindings, change the amplitude of the signal and set the brightness and contrast of the spectrogram by means of the sliding scales on the main screen.