Multi-resolution switched audio encoding/decoding scheme

Method of audio encoding an audio signal, comprising:

• encoding, in a first coding branch, an audio signal using a first coding algorithm to acquire a first encoded signal, the first coding branch comprising the first converter for converting an input signal into a spectral domain;
• encoding, in a second coding branch, an audio signal using a second coding algorithm to acquire a second encoded signal, wherein the first coding algorithm is different from the second coding algorithm, the second coding branch comprising a domain converter for converting an input signal from an input domain into an output domain, and a second converter for converting an input signal into a spectral domain;
• switching between the first coding branch and the second coding branch so that, for a portion of the audio input signal, either the first encoded signal or the second encoded signal is in an encoder output signal;
• analyzing the portion of the audio signal to determine, whether the portion of the audio signal is represented as the first encoded signal or the second encoded signal in the encoder output signal,
• variably determining a respective time/frequency resolution of the first converter and the second converter, when the first encoded signal or the second encoded signal representing the portion of the audio signal is generated;
• and
• generating an encoder output signal comprising the first encoded signal and the second encoded signal and information indicating the first encoded signal and the second encoded signal, and information indicating the time/frequency resolution applied for encoding the first encoded signal and for encoding the second encoded signal,
• wherein the analyzing determines the time/frequency resolution to be selected from a plurality of different window lengths, the different window lengths being at least two of 2304, 2048, 256, 1920, 2160, 240 samples, or uses the plurality of different transform lengths, the different transform lengths comprising at least two of the group comprising 1152, 1024, 1080, 960, 128, 120 coefficients per transform block, or
• wherein the analyzing determines the time/frequency resolution of the second converter as one of a plurality of different window lengths, the plurality of different window lengths being at least two of 640, 1152, 2304, 512, 1024 or 2048 samples, or uses a plurality of different transform lengths, the different transform lengths comprising at least two of the group comprising 320, 576, 1152, 256, 512, 1024 spectral coefficients per transform block.

Audio decoder for decoding an encoded signal, the encoded signal comprising a first encoded signal, a second encoded signal, an indication indicating the first encoded signal and the second encoded signal, and a time/frequency resolution information to be used for decoding the first encoded signal and the second encoded audio signal, comprising:

• a first decoding branch for decoding the first encoded signal using a first controllable frequency/time converter, the first controllable frequency/time converter being configured for being controlled using the time/frequency resolution information for the first encoded signal to acquire a first decoded signal;
• a second decoding branch for decoding the second encoded signal using a second controllable frequency/time converter, the second controllable frequency/time converter being configured for being controlled using the time/frequency resolution information for the second encoded signal;
• a controller for controlling the first frequency/time converter and the second frequency/time converter using the time/frequency resolution information;
• a domain converter for generating a synthesis signal using the second decoded signal;
• and
• a combiner for combining the first decoded signal and the synthesis signal to acquire a decoded audio signal,
• wherein the controller is configured for controlling the first frequency/time converter and the second frequency/time converter so that,
• for the first frequency/time converter the time/frequency resolution is selected from a plurality of different window lengths, the different window lengths being at least two of 2304, 2048, 256, 1920, 2160, 240 samples, or
• is selected from a plurality of different transform lengths, the different transform lengths comprising at least two of the group comprising 1152, 1024,1080, 960, 128, 120 coefficients per transform block, or
• for the second frequency/time converter the time/frequency resolution is selected as one of a plurality of different window lengths, the plurality of different window lengths being at least two of 640, 1152, 2304, 512, 1024 or 2048 samples, or
• is selected from a plurality of different transform lengths, the different transform lengths comprising at least two of the group comprising 320, 576, 1152, 256, 512, 1024 spectral coefficients per transform block.

Method of audio decoding an encoded signal, the encoded signal comprising a first encoded signal, a second encoded signal, an indication indicating the first encoded signal and the second encoded signal, and a time/frequency resolution information to be used for decoding the first encoded signal and the second encoded audio signal, comprising:

• decoding, by a first decoding branch, the first encoded signal using a first controllable frequency/time converter, the first controllable frequency/time converter being configured for being controlled using the time/frequency resolution information for the first encoded signal to acquire a first decoded signal;
• decoding, by a second decoding branch, the second encoded signal using a second controllable frequency/time converter, the second controllable frequency/time converter being configured for being controlled using the time/frequency resolution information for the second encoded signal;
• controlling the first frequency/time converter and the second frequency/time converter using the time/frequency resolution information;
• generating, by a domain converter, a synthesis signal using the second decoded signal;
• and
• combining the first decoded signal and the synthesis signal to acquire a decoded audio signal,
• wherein the controlling the first frequency/time converter and the second frequency/time converter is so that,
• for the first frequency/time converter the time/frequency resolution is selected from a plurality of different window lengths, the different window lengths being at least two of 2304, 2048, 256, 1920, 2160, 240 samples, or
• is selected from a plurality of different transform lengths, the different transform lengths comprising at least two of the group comprising 1152, 1024,1080, 960, 128, 120 coefficients per transform block, or
• for the second frequency/time converter the time/frequency resolution is selected as one of a plurality of different window lengths, the plurality of different window lengths being at least two of 640, 1152, 2304, 512, 1024 or 2048 samples, or
• is selected from a plurality of different transform lengths, the different transform lengths comprising at least two of the group comprising 320, 576, 1152, 256, 512, 1024 spectral coefficients per transform block.

Non-transitory storage medium having stored thereon a computer program for performing, when running on a processor, a method of audio encoding an audio signal, the method comprising:

• encoding, in a first coding branch, an audio signal using a first coding algorithm to acquire a first encoded signal, the first coding branch comprising the first converter for converting an input signal into a spectral domain;
• encoding, in a second coding branch, an audio signal using a second coding algorithm to acquire a second encoded signal, wherein the first coding algorithm is different from the second coding algorithm, the second coding branch comprising a domain converter for converting an input signal from an input domain into an output domain, and a second converter for converting an input signal into a spectral domain;
• switching between the first coding branch and the second coding branch so that, for a portion of the audio input signal, either the first encoded signal or the second encoded signal is in an encoder output signal;
• analyzing the portion of the audio signal to determine, whether the portion of the audio signal is represented as the first encoded signal or the second encoded signal in the encoder output signal,
• variably determining a respective time/frequency resolution of the first converter and the second converter, when the first encoded signal or the second encoded signal representing the portion of the audio signal is generated;
• and
• generating an encoder output signal comprising the first encoded signal and the second encoded signal and information indicating the first encoded signal and the second encoded signal, and information indicating the time/frequency resolution applied for encoding the first encoded signal and for encoding the second encoded signal,
• wherein the analyzing determines the time/frequency resolution to be selected from a plurality of different window lengths, the different window lengths being at least two of 2304, 2048, 256, 1920, 2160, 240 samples, or uses the plurality of different transform lengths, the different transform lengths comprising at least two of the group comprising 1152, 1024, 1080, 960, 128, 120 coefficients per transform block, or
• wherein the analyzing determines the time/frequency resolution of the second converter as one of a plurality of different window lengths, the plurality of different window lengths being at least two of 640, 1152, 2304, 512, 1024 or 2048 samples, or uses a plurality of different transform lengths, the different transform lengths comprising at least two of the group comprising 320, 576, 1152, 256, 512, 1024 spectral coefficients per transform block.

Non-transitory storage medium having stored thereon a computer program for performing, when running on a processor, a method of audio decoding an encoded signal, the encoded signal comprising a first encoded signal, a second encoded signal, an indication indicating the first encoded signal and the second encoded signal, and a time/frequency resolution information to be used for decoding the first encoded signal and the second encoded audio signal, the method comprising:

• decoding, by a first decoding branch, the first encoded signal using a first controllable frequency/time converter, the first controllable frequency/time converter being configured for being controlled using the time/frequency resolution information for the first encoded signal to acquire a first decoded signal;
• decoding, by a second decoding branch, the second encoded signal using a second controllable frequency/time converter, the second controllable frequency/time converter being configured for being controlled using the time/frequency resolution information for the second encoded signal;
• controlling the first frequency/time converter and the second frequency/time converter using the time/frequency resolution information;
• generating, by a domain converter, a synthesis signal using the second decoded signal;
• and
• combining the first decoded signal and the synthesis signal to acquire a decoded audio signal,
• wherein the controlling the first frequency/time converter and the second frequency/time converter is so that,
• for the first frequency/time converter the time/frequency resolution is selected from a plurality of different window lengths, the different window lengths being at least two of 2304, 2048, 256, 1920, 2160, 240 samples, or
• is selected from a plurality of different transform lengths, the different transform lengths comprising at least two of the group comprising 1152, 1024,1080, 960, 128, 120 coefficients per transform block, or
• for the second frequency/time converter the time/frequency resolution is selected as one of a plurality of different window lengths, the plurality of different window lengths being at least two of 640, 1152, 2304, 512, 1024 or 2048 samples, or
• is selected from a plurality of different transform lengths, the different transform lengths comprising at least two of the group comprising 320, 576, 1152, 256, 512, 1024 spectral coefficients per transform block.