Method for adjusting windowing signal MDCT domain energy and phase and device thereof

Abstract

The present invention provides a method for adjusting windowing signal MDCT domain energy and phase, and a device thereof. The method includes steps as follows: constructing windowing signal CMCLT spectrum according with the windowing signal MDCT spectrum and the MDST spectrum; extracting the energy information and phase information of the windowing signal on the CMCLT domain, then extracting space parameter on the MDST domain according with the obtained energy information and the phase information. The CMCLT spectrum is a conjugate concoct duplicate superpose conversion spectrum which is a complex number stretched form with the MDCT spectrum and the MDST spectrum as a real part and a imaginary part by using a window function as a conjugate window function, accordingly, defining MDCT. The method and the device can uniform a time frequency analyzing tool in a space audio encoding system, extract the space parameter of multi-acoustic channel signal. Whole encoding end only needs once time frequency conversion after uniforming the time frequency conversion tool which can reduce complicated degree of the space audio- coding and encoding system, accordingly, optimize coding and encoding work.

Description

technical field [0001] The invention belongs to the technical field of spatial audio, in particular to a method and a device for adjusting the energy and phase of a windowed signal in the MDCT domain. Background technique [0002] The audio signal is a short-term stationary process. In actual signal processing, the signal of each frame with stationary statistical characteristics is taken as the processing object by sampling the signal into frames. Signal framing is equivalent to using a common rectangular window to truncate the signal. Since the rectangular window has a steep falling edge to zero, the spectrum leaks between frames after framing, causing the reconstructed sound signal to jitter between frames. Therefore, it is necessary to add a window to the time-domain signal before transforming to avoid the block effect caused by sub-framing and ensure the smooth transition between frames. Multi-channel audio coding technology pursues high sound quality and low bit rate. ...

AI Technical Summary

Problems solved by technology

[0008] However, the MDCT transform belongs to the real transform, which is different from the complex transform that contains signal phase information and amplitude information at the same time. It is difficult to extract spatial parameters in the MDCT domain: firstly, the energy jitter of the MDCT spectrum makes the inter-channel intensity difference ILD of the MDCT spectrum and the original The windowed signal ILD is inconsistent, resulting in differences in the extraction of ILD parameters; secondly, the MDCT spectrum does not contain direct phase information, which makes it difficult to reflect the delay characteristics of the original time-domain windowed signal, resulting in difficulties in directly extracting the time difference parameter ITD between channels

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