Alias cancelling during audio coding mode transitions

An apparatus for processing an audio signal, comprising:

• a de-multiplexer receiving an audio signal including a first data of a first block encoded with a rectangular coding scheme and a second data of a second block encoded with a non-rectangular coding scheme, and receiving a compensation signal corresponding to the second block;
• a rectangular decoding unit generating an output signal for the first block using the first data of the first block based on the rectangular coding scheme, and obtaining a prediction of an aliasing part by applying a window of the second block to the output signal for the first block;
• and
• a non-rectangular decoding unit obtaining a reconstructed signal for the second block based on the second data, the compensation signal and the prediction of the aliasing part,
• wherein, when the first data is encoded with a LPD (Linear Prediction Domain) coding scheme and the window of the second block belongs to a transition window class, the window of the second block has an ascending line with a first slope,
• wherein the first slope is gentler than a second slope.

A method for processing an audio signal including a first data of a first block encoded with a first coding scheme using a rectangular window and a second data of a second block encoded with a second coding scheme using a non-rectangular window, the method comprising:

• generating, by an audio processing apparatus, an output signal for the first block using the first data of the first block based on the first coding scheme;
• receiving a compensation signal corresponding to the second block;
• obtaining a prediction of an aliasing part by applying a window of the second block to the output signal for the first block;
• and
• obtaining a reconstructed signal for the second block based on the second data, the compensation signal and the prediction of the aliasing part, wherein, the first data is encoded with a LPD (Linear Prediction Domain) coding scheme and the window of the second block belongs to a transition window class.

An apparatus for processing an audio signal that includes (i) a first data of a first block encoded with a first coding scheme using a rectangular window, (ii) a second data of a second block encoded with a second coding scheme using a non-rectangular window, and (iii) a compensation signal corresponding to the second block, the apparatus comprising::

• a de-multiplexer configured to receive the audio signal;
• a rectangular decoding unit configured to generate an output signal for the first block using the first data of the first block based on the first coding scheme, and to obtain a prediction of an aliasing part by applying a window of the second block to the output signal for the first block;
• and
• a non-rectangular decoding unit configured to obtain a reconstructed signal for the second block based on the second data, the compensation signal and the prediction of the aliasing part, wherein, the first data is encoded with a LPD (Linear Prediction Domain) coding scheme and the window of the second block belongs to a transition window class.