Audio Bit Depth and Bandwith Evaluator Plugin

This Audio Plugin lets you evaluate the audible impact of audio sample resolution and audio bandwidth.

The BITS_and_BW_evaluator_Plugin.m lets you evaluate the audible impact of audio sample resolution and bandwidth, useful for determining e.g. your own detection threshold of "High-Res Audio" formats.

You can evaluate changes of bit depth and bandwidth through real-time listening or via file output (for e.g. ABX testing).

You can evaluate the effect of various bit truncation methods, and see the exact noise performance in graphs.

You can evaluate a specific content bandwidth, and see the exact filter performance in graphs.

• Bit depths between 2-24 bits are emulated (Truncation, Rounding or Dithering).
• Bandwith limitation between 2-22 kHz is emulated (linear phase LP filtering).
• Plots showing the errors induced from specific truncation methods is available.
• Plots showing the specific LP filter performance is available.
• Volume and filter changes are implemented with smoothing (click free).
• Matlab Audio Plug-in spectrum analysis window lets you conveniently monitor actual signal and noise power in real-time.
• Processing order is: IN -> Bit Reduction -> LowPass Filter -> Volume Control -> OUT

Changes in this version (compared to 1.0.0 version):

• Swapped processing order of Bit Reduction and LowPass Filter.
• Extended LP filter upper limit from 20k to 22kHz.

General comments:

• Run by typing the command: audioTestBench('BITS_and_BW_evaluator_Plugin')
• It is not very optimized for performance, hence requires a resonably powerful computer, or can produce noticable artifacts.
• The plots take a bit of time to generate, and meanwhile music pauses. Just wait for it...
• Unfortunately I wasn't able to create a VST plug-in due to soem sample rate error message.
• HAPPY FOR ANY SUGGESTIONS ON IMPROVEMENTS OF FUNCTION OR PERFORMANCE!

// Andrej Petef, 2023-01-01

// Original version created 2017