How can I visualize real-time audio signals in Qt using Qwt Oscilloscope?

Plotting Real-Time Data on (qwt) Oscillocope

In order to visualize an audio signal recorded through Qt using QAudioInput and QIODevice, you can utilize the following steps:

Timebase:

• Determine the input signal sampling frequency (fsmpl).
• Calculate the maximum detectable frequency as fsmpl/2.
• Set the lower limit of the timebase based on the buffer length.

Drawing:

• Create a function to render the sampling buffer from a specified start address, accommodating:

  • Y-scale for amplitude adjustment
  • Y-offset for vertical beam positioning
  • X-offset for time shift or horizontal positioning

Level:

• Implement a function simulating the Level functionality:

  • Search the buffer from the start address
  • Stop when the amplitude crosses the specified level
  • Configure various modes for level detection, such as amplitude crossing levels or relative edge detection

Preview:

• Trigger the level function at regular intervals to identify the start address.
• Call the draw function with the updated start address, adding the timebase period to it.

Multichannel:

• Split the interlaced data coming from a single buffer into separate channels (e.g., left and right).
• Incorporate level source and render mode options for each channel.

Miscel Stuff:

• Enable additional features like:

  • Analog knob settings for amplitude, timebase, level, and offsets
  • Discrete settings for level mode and channel options
  • Filters emulating capacitance or grounding

GUI:

• Design an intuitive graphical user interface (GUI) with a range of analog and discrete settings.

Trigger:

• Trigger all channels simultaneously based on a defined condition.
• For instance, search for when the left channel amplitude rises above a specified level and start drawing from that point.

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