Audio coder window sizes and time-frequency transformations

A method for decoding an encoded bitstream having a plurality of encoded frames, comprising:

• receiving a first encoded frame of the plurality of encoded frames, wherein each of the plurality of encoded frames contains subband data for a plurality of subbands;
• determining, from the first encoded frame, a first window for the first encoded frame, a first transform size for the first encoded frame, and a first set of time-frequency resolutions corresponding to the plurality of subbands in the first encoded frame;
• modifying subband data for the first encoded frame based on the first set of time-frequency resolutions to obtain modified subband data for the first encoded frame;
• applying an inverse transform to the modified subband data for the first encoded frame based on the first transform size to obtain inverse-transformed data for the first encoded frame;
• applying a window to the inverse-transformed data for the first encoded frame based on the first window to obtain windowed data for the first encoded frame;
• and
• determining a first decoded frame based on the windowed data for the first encoded frame.

An audio decoder, comprising:

• at least one processor;
• one or more computer-readable mediums storing instructions that, when executed, cause the at least one processor to perform operations comprising:
• receiving a first frame of an encoded audio signal and a second frame of the encoded audio signal, wherein the first frame and the second frame each contain subband data corresponding to a plurality of subbands, modification information for at least one of the plurality of subbands, transform size information, and window information;
• for the first frame, modifying a time-frequency resolution of a first subband of the plurality of subbands based at least in part on the modification information of the first frame to determine modified subband data for the first subband to obtain a first modified subband of the first frame;
• for the second frame, modifying a time-frequency resolution of a second subband of the plurality of subbands based at least in part on the modification information of the second frame to determine modified subband data for the second subband to obtain a second modified subband of the second frame;
• determining a first decoded frame using at least the first modified subband of the first frame;
• and
• determining a second decoded frame using at least the first second modified subband of the second frame.