Need guidance: visualize system audio without saving to file

[nshalabi]

Hello,

I’ve been exploring MfPack and the loopback capture samples, and they are very close to what I need — great work on this library.

I would like to create a real-time visualization similar to the TMfPeakMeter component, but instead of visualizing audio from a media file or recorder, I want to visualize system-wide audio captured via WASAPI loopback (“what you hear”).

My goal is:

• Capture the system audio using the existing loopback capture functionality
• Detect audio levels (peak/RMS) in real time
• Drive a visual component (VU meter / bars / spectrum)
• No file writing, no recording — purely real-time visualization

From reviewing the samples, it seems the audio data is already available in the capture buffer (e.g. around IAudioCaptureClient.GetBuffer). I wanted to ask:

• Is there an existing component or helper in MfPack designed for this use case?
• Or would you recommend extending TMfPeakMeter to work with loopback capture data?

Any guidance on the intended integration point would be greatly appreciated.

Thank you for the excellent library.

[FactoryXCode]

Hi Nader,

By default the peakmeter property DeviceRole is set to eMultimedia (Music, movies, narration, and live music recording.) What you want is property DeviceRole = eConsole (Games, system notification sounds, overall sound, and voice commands.)
So, you have to set the peakmeter property to eConsole.

You could write an app with just one window that holds the peakmeters, set the peakmeter properties and there you have the live vu after you enable the peakmeters.

The MfPack Peakmeter is designed to be a separate working code that picks up every sound from the system, independent from what application you use.

Best regards, Tony.

[FactoryXCode]

Ok,
I had some time to search in my code base, this is maybe something you want.
It's tested code and it's a Delphi TComponent DSP (Real-time system audio loopback capture, Peak/RMS, optional Spectrum (FFT) or VU).
We decided to include it in the MFComponents. See: MfAudioVisualizer
Regards, Tony & Carmen.