Version 3.0

Contents

 
Description

DXVU Meter is an ActiveX control, that can monitor any audio device configured as a recording source, such as a Microphone, the CD ROM, etc... and display the monitored audio levels like a standard VU Meter or as an Oscilloscope.

The VU display mode works by calculating the RMS value of the monitored audio and display the peak value in the form of a peak bar.

The Oscilloscope works by taking samples of the monitored data and display it as a waveform.



DXVU Meter is also capable of saving the monitored audio to a WAV file and since it uses a circular (or infinite) buffer there's no limitation on the amount of audio that can be captured or saved.

The interface of the control is fully resizable in order to let it fit into any form design. The VU mode also supports vertical and horizontal placement of the bars.

 

Requirements

DXVU Meter uses the DirectX 8.0 interface, so in order to use the control the target machine must have the DirectX 8.0 runtime libraries installed.

These libraries are free and can be obtained from Microsoft at their DirectX web site: http://microsoft.com/directx

 

Testing the Control

To test the control, first, you should have some audio device playing, such as the CD-ROM playing and selected as the recording source.
To select a recording source open the Windows Mixer, select Options->Properties, choose the Recording round check and click OK. Now make sure the CD-ROM line has a checkbox in the "Select" option and the Volume is high enough.

Now, simply run one of the Tester applications and click on the "StartVU" button.

 

Known Bugs & DEMO Limitations

Bugs:

When placing the control in a form for the first time, all the leds will appear green. Their color will be restored when running the application or by changing any of the leds color. This issue is currently being investigated.

Under Windows 9x/Me, shutting down the control (by issuing the StopVU method) will take from 3 to 7 seconds. Under Windows 2000 and XP the control takes less than 1 seconds to perform the exact same operation.

Demo Limitations:

A nag screen will be displayed every time the control is initialized.

How to Contact us

If you wish to write us with your opinions, suggestions or bug reports about this release of DXVU Meter, please use our online support form at:
http://software.xfx.net/support.htm

You may also want to visit a public forum, dedicated to DXVU Meter at:
http://software.xfx.net/uboards/uboard_ax.htm

 

Pricing

The control will be made available in both, the binary version and the control's full source code.

Binary
Including Documentation and three tester applications with their source code		 US$  35.00
Source Code US$ 380.00

To buy this control online, please follow this link:
http://software.xfx.net/activex/dxvu/register.htm

 

What's New

Version 3.0.000

  • The rendering engine to display the Oscilloscope mode (wave form) now uses the DirectX API instead of the GDI producing a much more fluid wave form while requiring fewer CPU resources.
  • The code has been optimized so multiple controls can be used simultaneously on the same application.
    This optimization should also provide a small performance boost.
  • Fixed bug that caused the control to invert the left and right channels.
  • Added support to playback any type of media file.
    The media files that can be played with DXVU Meter will depend on the filters available on the host machine. This means that if the host machine has a filter to decode MP3 files, then DXVU Meter will be able to playback MP3 files.
  • Added two new properties:
  • Added one new method:
  • Added two new samples with source code.
  • Highly improved performance and memory utilization now allows the control to run with fewer CPU resources.

Version 2.0.008

  • Added support for five new events:
    • Click
    • DblClick
    • MouseDown
    • MouseMove
    • MouseUp
  • The Calibration property now affects the oscilloscope mode.
  • Slightly improved quality of the rendering engine while in oscilloscope mode to properly reflect clipping and to avoid flickering.

Version 2.0.007

  • Highly improved playing quality. The control will not properly stream wav files and play them without introducing any noise. It will also stop the playback more accurately.
  • Added support to play files in loop mode.
  • Add two new sample applications:
    • Get DirectX 8 Capabilities: This application will use the DirectX 8 API to retrieve the supported playing and recording formats for all the installed sound cards.
    • Sample Recorder: One of the most requested samples is an application that can detect the audio level on some of the input lines and record or stop recording based on a pre-set set point.
      This application monitors a specific input line and starts recording when the audio level goes above the set point.
      When a silence is detected the application will wait a pre-defined delay and then stop recording if the duration of the silence extends the pre-set delay.

Version 2.0.001

  • Fixed bug that caused the led display to render the monitored and played audio incorrectly when a 16bit/Mono mode was selected.
  • Fixed bug that caused the Resolution property to be improperly initialized when the control was created.
  • Added a new property to set the background color of the control while in the Leds mode.
  • Improved the led display.

Version 2.0.000

  • Documented the Calibration property on the documentation.
  • Added the return data type information to all the properties on the documentation.
  • The SoundDriverCount property now returns a Long as recommended by Microsoft's DirectX documentation.
  • Added a new property to set the number of leds to be displayed while the control is used in VU mode.
  • Added support for selecting the output device for Playback. (See the SoundDriver and SoundDriverType properties)
  • The VU mode now calculates an average between the last three values monitored to create a smoother display.
  • The control has been re-calibrated providing more realistic results in the rendering engine. This has also affected the way the array returned by the PeakValues event should be interpreted.
    The control should now display 99% exact results regardless of the sampling frequency being used, of course, as long as the sampling frequency is at least twice the central frequency of the sampled data. Because of this, you may notice that the rendering engine tends to display the same sampled audio at lower levels when using lower sampling frequencies; this is just a result of the information being lost at the sampling process.
  • Fixed bug that caused the control to improperly monitor stereo sound under some frequencies.
  • All the sample applications have been re-adjusted to accommodate to the new Calibration system used by the control.
  • The DXVUMeterTester application has been updated to reflect the new ability of the control to select the playback device.
  • The Frequency Analyzer 2.0 has been updated (it's still considered in beta state) and now includes a small document explaining all the features.

Version 1.x update log