摘要
提出了一种基于离散傅里叶变换(MDFT)域的频带扩展技术,可有效地提高音频编码效率。相对于既有方法,本方法在MDFT域进行频带扩展,能与低频编码所采用的MDCT变换相协调,有效利用低频编码过程中的既有数据,通过灵活的块切换方式来有效提高高频参数编码的效率。通过由MDCT域频谱转换得到MDFT域频谱数据,避免了进行MDFT时频变换,从而在保持音频信号编码质量的前提下,有效降低了解码器的计算复杂度。
A band extension technology based on discrete Fourier transform （MDFT） domain is proposed, which can effectively improve the audio coding efficiency. Relative to the existing method, the frequency band can be extended in MDFT domain and coordinated with the MDCT transform in low frequency coding. The existing data are effectively used during the low frequency encoding, and the efficiency of high frequency parameter coding is improved by a flexible way of block switching. MDFT is avoided since MDFT domain spectrum is converted directly through MDCT domain spectrum, thus the computational complexity of the decoder is effectively reduced with maintaining the quality of the audio signal coding.
出处
《电声技术》
2015年第1期48-51,共4页
Audio Engineering
