Low-code-rate audio quality objective evaluation method based on nonlinear parameter fitting

Abstract

The invention discloses a low-code-rate audio quality objective evaluation method based on nonlinear parameter fitting, which belongs to the field of communication. The method is characterized by including steps: firstly, selecting some audio frequencies with typical characteristics, compressing the audio frequencies at different code rates, and subjectively evaluating and marking the audio frequencies decompressed after being compressed; secondly, extracting code rate and scale factor of each audio frequency at each code rate, subjectively evaluating and marking independently at each code rate and performing nonlinear parameter fitting of the scale factors to obtain respective fitting formula at each code rate; and thirdly, extracting the code rate and the scale factor from audio stream needed to be objectively evaluated, selecting the corresponding formula according to the code rate and substituting the scale factor in the formula to obtain the objective evaluation mark of the audio frequency by calculating. The independent parameter fitting at each code rate can eliminate influences of different code rates and more accurately measure quality damage caused by quantization. The conditions that the mark is higher when the scale factor is smaller or larger and the mark is lower when the scale factor is medium can be simulated by means of nonlinear parameter fitting of the subjective evaluation mark and the scale factor, fitting degree is improved, and subjective evaluation can be better simulated by objective evaluation.

Description

technical field [0001] The invention relates to a method for objectively evaluating audio quality and belongs to the field of communication. Background technique [0002] With the development of multimedia technology, digital compressed audio is widely used in the fields of network, broadcasting, film and television, and mobile multimedia communication. However, audio compression is lossy compression, and compression will cause a decrease in audio quality. In order to ensure better audio quality for the user, it is necessary to evaluate the quality of the compressed audio. Evaluation methods of audio quality include subjective evaluation methods and objective evaluation methods. [0003] The results of the subjective evaluation are consistent with the actual feelings of the human ear. However, subjective evaluation requires a large cost, time-consuming, and laborious; subjective evaluation is greatly affected by the listener's physiological and psychological conditions, l...

AI Technical Summary

Problems solved by technology

PEAQ is a full-reference audio quality evaluation method. It needs to refer to the original audio for objective audio quality evaluation. It is difficult to obtain the original audio in practical applications; PEAQ is suitable for objective evaluation of audio quality at high bit rates, and damages in low bit rate compressed audio It is different from high bit rate compression; PEAQ has high computational complexity and is not suitable for applications that require high real-time performance

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