Ye Ma

An Even Grid Based Lattice Vector Quantization Algorithm for Mobile Audio Coding

This paper proposed an even grid based lattice vector quantization method for audio coding. The method uses energy priority, with basic code book and the ball-type expansion, which is applicable to the low rate of the variable-rate vector quantization coding. The method uses the lattice characteristics to resolve rapid index distribution problem, as well as the compression of the basic code book. The experiment results show that the proposed method is as good as vector quantization method in ITU-T standard G729.1 in quality, with lower storage cost and computational complexity.

Bandwidth Extension Method Based on Spectral Envelope Estimation

In current communication system, high quality audio signal is supposed to be provided with low bit rate and low computational complexity. This paper proposed a novel audio coding bandwidth extension method, which can improve decoded audio quality with increasing only a few coding bits per frame and a little computational complexity. This method calculate high-frequency synthesis filter by using codebook mapping method, and transmit only quantified gain corrections in high-frequency part of multiplexing coding bit stream. The preliminary test show that this method can provide comparable audio quality with lower bit consumption and computational complexity compared to the high frequency regeneration of AMR-WB+.

A bottom-up audio attention model for surveillance

This paper proposes a bottom-up audio attention model based on spatial audio cues and sub band energy change for unsupervised event detection in stereo audio surveillance. Firstly, the spatial audio parameter Interaural Level Difference (ILD) is extracted to calculate and represent the attention events, which are caused by rapid moving sound source. Then the sub band energy change is computed to present the salient energy distribution change in frequency domain. At last, an environment adaptive normalization is used to assess the normalized attention level. Experimental results demonstrate that the proposed audio attention model is effective for audio surveillance event detection.

Surveillance Audio Attention Model Based on Spatial Audio Cues

For stereo audio surveillance in complex environment, we proposed a bottom-up audio attention model based on spatial audio cues analysis, and an environment adaptive normalization method. The traditional audio attention models are based on mono audio characters, such as energy, energy peak, or pitch. Their performance is limited by neglecting the spatial information. The spatial cues in audio stream provide additional information for attention analysis. And the dynamic updated background sound can help to reduce the environment effect. The preliminary experiment showed that the proposed model is an effective way to analyzing attention events, which is caused by rapid moving sound source, in stereo audio stream.

Virtual Conference Audio Reconstruction Based on Spatial Object

This paper proposed a virtual conference audio reconstruction model based on spatial audio object. The aim of the model is to enhance the realistic experience of virtual conference. Firstly, the conference audio synthesis method is given according the principle of the virtual conference. Then the spatial audio parameters interaural level difference (ILD) are used to reconstruct the spatial sound field for each listener based on the theory of spatial audio object coding.

A Novel Low Bit Rate Audio Bandwidth Extension Method

In present communication system, high quality audio signal is supposed to be provided with low bit rate and low computational complexity. This paper proposed a novel audio coding bandwidth extension method, which can improve decoded audio quality with increasing only a few coding bits per frame and a little computational complexity. This method calculate high-frequency synthesis filter by using codebook mapping method, and transmit only quantified gain corrections in high-frequency part of multiplexing coding bit stream. The preliminary test show that this method can provide comparable audio quality with lower bit consumption and computational complexity compared to the high frequency regeneration of AMR-WB+.