Apparatus and method for generating a synthesis audio signal and for encoding an audio signal

摘要

An apparatus for generating a synthesis audio signal using a patching control signal has a first converter, a spectral domain patch generator, a high frequency reconstruction manipulator and a combiner. The first converter is configured for converting a time portion of an audio signal into a spectral representation. The spectral domain patch generator is configured for performing a plurality of different spectral domain patching algorithms, wherein each patching algorithm generates a modified spectral representation having spectral components in an upper frequency band derived from corresponding spectral components in a core frequency band of the audio signal. The spectral domain patch generator is furthermore configured to select a first spectral domain patching algorithm from the plurality of patching algorithms for a first time portion and a second spectral domain patching algorithm from the plurality of patching algorithm for a second different time portion in accordance with the patching control signal to obtain the modified spectral representation.

主权项

1. An apparatus for generating a synthesis audio signal using a patching control signal, the apparatus comprising:
a first converter for converting a time portion of an audio signal into a spectral representation; a spectral domain patch generator for performing a plurality of different spectral domain patching algorithms, wherein each patching algorithm generates a modified spectral representation comprising spectral components in an upper frequency band derived from corresponding spectral components in a core frequency band of the audio signal, and wherein the spectral domain patch generator is configured to select a first spectral domain patching algorithm from the plurality of patching algorithms for a first time portion and a second spectral domain patching algorithm from the plurality of patching algorithms for a second different time portion in accordance with the patching control signal to achieve the modified spectral representation; a high frequency reconstruction manipulator for manipulating the modified spectral representation or a signal derived from the modified spectral representation in accordance with a spectral band replication parameter to achieve a bandwidth extended signal; and a combiner for combining the audio signal comprising spectral components in the core frequency band or a signal derived from the audio signal with the bandwidth extended signal to achieve the synthesis audio signal, wherein the spectral domain patch generator is configured for performing at least two different spectral domain patching algorithms from a group of patching algorithms in the spectral domain, the group of patching algorithms comprising a first patching algorithm comprising a harmonic transposition based on a single phase vocoder and non-harmonic copying-up spectral band replication functionalities, a second patching algorithm comprising a harmonic transposition based on a multiple phase vocoder, a third patching algorithm comprising non-harmonic copying-up spectral band replication functionalities and a fourth patching algorithm comprising a non-linear distortion, and wherein at least one of the first converter, the spectral domain patch generator, the high frequency reconstruction manipulator and the combiner comprises a hardware implementation.