Unified speech/audio codec (USAC) processing windows sequence based mode switching
A Unified Speech and Audio Codec (USAC) that may process a window sequence based on mode switching is provided. The USAC may perform encoding or decoding by overlapping between frames based on a folding point when mode switching occurs. The USAC may process different window sequences for each situation to perform encoding or decoding, and thereby may improve a coding efficiency.
1. A signal processing method processed by a processor, comprising:
identifying a first window for a previous frame of an input signal;
identifying a second window for a current frame of the input signal;
modifying a slope of a left portion of the second window based on the first window, and
processing the current frame using a modified second window having a modified left portion by performing overlap-add operation between the previous frame applied to the first window and the current frame applied to the modified second window, and
wherein the overlap-add operation is performed at a folding point with respect to the first window and the second window.
2. The signal processing method of claim 1 , wherein the slope of the left portion of the second window corresponds to a region for performing overlap-add operation with the first window.
3. The signal processing method of claim 1 , wherein the current frame is applied to a Linear Prediction Domain (LPD) mode and the previous frame is applied to a Frequency Domain (FD) mode.
4. The signal processing method of claim 1 , wherein the current frame is applied to a Linear Prediction Domain (LPD) mode and the previous frame is applied to the LPD mode.
5. The signal processing method of claim 1 , wherein the current frame is applied to Frequency Domain (FD) and the previous frame is applied to a Linear Prediction Domain (LPD) mode.
6. A signal processing method processed by a processor, comprising:
identifying a first window for a current frame of an input signal;
identifying a second window for a next frame of the input signal;
modifying a slope of a right portion of the first window based on the second window, and
processing the current frame using a modified first window having a modified right portion overlap-add operation between the current frame applied to the modified first window and the next frame applied to the second window, and
wherein the overlap-add operation is performed at a folding point with respect to the first window and the first window.
7. The signal processing method of claim 6 , wherein the slope of the right portion of the first window corresponds to a region for performing overlap-add operation with the second window.
8. The signal processing method of claim 6 , wherein the current frame is applied to a Linear Prediction Domain (LPD) mode and the next frame is applied to a Frequency Domain (FD) mode.
9. The signal processing method of claim 6 , wherein the current frame is applied to a Linear Prediction Domain (LPD) mode and the next frame is applied to the LPD mode.
10. The signal processing method of claim 6 , wherein the current frame is applied to Frequency Domain (FD) and the next frame is applied to a Linear Prediction Domain (LPD) mode.