AUDIO SIGNAL SYNTHESIZER AND AUDIO SIGNAL ENCODER

摘要

An audio signal synthesizer generates a synthesis audio signal having a first frequency band and a second synthesized frequency band derived from the first frequency band and comprises a patch generator, a spectral converter, a raw signal processor and a combiner. The patch generator performs at least two different patching algorithms, each patching algorithm generating a raw signal. The patch generator is adapted to select one of the at least two different patching algorithms in response to a control information. The spectral converter converts the raw signal into a raw signal spectral representation. The raw signal processor processes the raw signal spectral representation in response to spectral domain spectral band replication parameters to obtain an adjusted raw signal spectral representation.

主权项

1. An audio signal encoder for generating from an audio signal a data stream comprising components of the audio signal in a first frequency band, control information and spectral band replication parameters, comprising:
a frequency selective filter to generate the components of the audio signal in the first frequency band; a generator for generating the spectral band replication parameter from the components of the audio signal in a second frequency band; a control information generator to generate the control information, the control information identifying a patching algorithm from a first or a second different patching algorithm, wherein each patching algorithm generates a raw signal comprising signal components in the second replicated frequency band using the components of the audio signal in the first frequency band, wherein the control information generator is adapted to identify the patching algorithm by comparing the audio signal with patched audio signals for the first and for the second patching algorithms, wherein differently patched audio signals are derived from different raw signals related to the first and the second patching algorithms by applying raw signal adjusting in response to spectral band replication parameters with a spectral band replication tool.