Clicky

PVQA is a quite unique powerful tool to non-intrusively evaluate voice quality by waveform analysis. The tool is based on Sevana Voice Quality Impairments Detection Library, it does not require reference audio and works in two modes:

  • MOS score prediction with impairments analysis
  • Bulk analysis of voice quality impairments present in the test audio

PVQA MOS score is perhaps the most accurate compared to other tools that predict MOS score non-intrusively by waveform analysis. Tool performance and ability to work in real-time give companies an opportunity to develop their own voice quality testing solutions not being dependent of particular hardware and software. PVQA is available as console application and library for Windows and Linux, portable to Java and mobile devices.

Requirements

PVQA is capable to work with audio files represented in .wav format of telephone quality. Audio files should be 8kHz, 16 bit, Mono. Please contact Sevana Oü if interested in working with other file formats or higher sampling rate.

Scientific Background

Perfect sound quality in telecommunications systems depends on absence or insignificant influence of impairments affecting encoding, transmission, and amplification. Perceptual model of PVQA is based on detecting voice quality impairments known to degrade quality of audio for human perception. At first stage the software detects impairments and at the second stage uses proprietary algorithms to convert them into MOS score prediction according to ITU-T P.800 standard.

PVQA Command Line Parameters

Calculate MOS non-intrusively

 pvqa.exe pvqa.lic analysis ENG_F_40.wav.csv Settings.cfg ENG_F_40.wav 0.799

or in Linux

./pvqa ./pvqa.lic analysis ./ENG_F_40.wav.csv ./Settings.cfg ./ENG_F_40.wav 0.799

pvqa.lic parameter is PVQA license file prepared and delivered by Sevana.

analysis  is parameter that sets operation mode of PVQA. Another option is “graph”

ENG_F_40.wav.csv is the name of report file where PVQA will store information about impairments found in time slots defined.

Settings.cfg is PVQA settings file prepared and provided by Sevana.

ENG_F_40.wav is uncompressed wav file for testing

0.799 is time slot in seconds PVQA will be analyzing for impairments and then use to predict MOS score.

All these parameters were worked out and preset by Sevana team to achieve higher conformance between more accurate intrusively measured MOS scores (see Sevana AQuA (Audio Quality Analyzer) for intrusive analysis) and non-intrusive scores returned by PVQA. We strongly recommend not to change anything without approval from Sevana team.

PVQA will give the following output:

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Sevana Impairments Detection Library Demo.

Copyright (c) 2015 by Sevana Finland/Estonia.

All rights reserved.

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Evaluation

Today is 15/08/07. This program is licensed to work until 15/08/14

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File ENG_F_40.wav degraded up to 0.948079 percent.

Found 18 poor intervals. Total 19 intervals.

MOS = 1.210526

The MOS score is quite low, but this is a very reasonable result considering that the test file has 40% packet loss and one will find its sound quality very low when listening to it.

If one tests the same audio with just 10% packet loss result will be the following:

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Sevana Impairments Detection Library Demo.

Copyright (c) 2015 by Sevana Finland/Estonia.

All rights reserved.

—————————————————————

Evaluation

Today is 15/08/10. This programm is licensed to work until 15/08/14

—————————————————————

File ENG_F_10.wav degraded up to 0.352348 percent.

Found 8 poor intervals. Total 19 intervals.

MOS = 3.315789

Bulk impairments detection throughout test audio

pvqa.exe pvqa.lic graph ENG_F_40.wav.rep Settings.cfg ENG_F_40.wav

or in Linux:

./pvqa ./pvqa.lic graph ./ENG_F_40.wav.rep ./Settings.cfg ./ENG_F_40.wav

pvqa.lic parameter is PVQA license file prepared and delivered by Sevana.

graph  is parameter that sets operation mode of PVQA. Another option is “analysis”

ENG_F_40.wav.rep is the name of report file where PVQA will store information about impairments found throughout the whole test file.

Settings.cfg is PVQA settings file prepared and provided by Sevana.

ENG_F_40.wav is uncompressed wav file for analysis

Output is stored in ENG_F_40.wav.rep and represented as CSV, e.g.:

Time; SNR-00; DeadAir-01; DeadAir-00; AMPC-00; VADC-00; Click-00;

6.820000; 21.259331; 1; 0; 0.000000; 0.000000; 0;

6.830000; 21.259331; 1; 0; 0.000000; 0.000000; 0;

6.840000; 21.259331; 1; 0; 0.000000; 0.000000; 0;

6.850000; 21.259331; 1; 0; 0.000000; 0.000000; 0;

6.860000; 21.259331; 1; 0; 0.000000; 0.000000; 0;

6.870000; 21.259331; 1; 0; 0.000000; 0.000000; 0;

6.880000; 21.259331; 1; 0; 0.000000; 0.000000; 1;

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