Decoder-based transient signal post-processing for ITU-T G.719 at low bit rate

作者：Wang Jing^*; Ji Xuan; He Hailong; Kuang Jingming

来源：Journal of Beijing Institute of Technology, 2012, 21(3): 370-375.

• Discrete cosine transform (DCT)
• Post-filter in frequency domain
• Short-term post-filter
• Spectral tilter compensation filter
• Transient audio

Associated with ITU-T G.719, a post-processing method in frequency domain for enhancing the perceptual quality of the decoded transient audio is proposed only to the audio decoder with no side information from the encoder. The proposed post-filter is used to filter the frequency coefficients of the decoded transient frame and consists of a short-term post-filter and a spectral tilt compensation filter which are derived from linear predictive coding (LPC) predictor based on the discrete cosine transform (DCT) coefficients of the decoded transient frame. As a result, the post-filter in frequency domain shapes the temporal noise in time domain and controls the pre-echo noise effectively while enhancing the transient perception. Listening test results show that the preferring ratio of the post-processed transient signal is higher than that of the original decoded signal at a low bit rate of 32 kbit/s in G.719 and the post-processing module brings a complexity of 12.399 WMOPS to the decoder.

• 出版日期2012
• 单位北京理工大学