Apparatus and method for generating a multi-channel synthesizer control signal, multi-channel synthesizer, method of generating an output signal from an input signal and machine-readable storage medium

Method of generating a multi-channel synthesizer control signal, comprising:

• analyzing a multi-channel input signal;
• determining smoothing control information in response to the signal analyzing step, such that, in response to the smoothing control information, a post-processing step generates a post-processed reconstruction parameter or a post-processed quantity derived from the reconstruction parameter for a time portion of an input signal to be processed;
• and
• generating a control signal representing the smoothing control information as the multi-channel synthesizer control signal.

Multi-channel synthesizer for generating an output signal from an input signal, the input signal having at least one input channel and a sequence of quantized reconstruction parameters, the quantized reconstruction parameters being quantized in accordance with a quantization rule, and being associated with subsequent time portions of the input signal, the output signal having a number of synthesized output channels, and the number of synthesized output channels being greater than the number of input channels, comprising:

• a control signal provider for providing the multi-channel synthesizer control signal having smoothing control information, wherein the multi-channel synthesizer control signal representing the smoothing control information is associated to the at least one input channel;
• a post-processor for determining, in response to the control signal, the post-processed reconstruction parameter or the post-processed quantity derived from the reconstruction parameter for a time portion of the input signal to be processed, wherein the post-processor is operative to determine the post-processed reconstruction parameter or the post-processed quantity such that the value of the post-processed reconstruction parameter or the post-processed quantity is different from a value obtainable using requantization in accordance with the quantization rule;
• and
• a multi-channel reconstructor for reconstructing a time portion of the number of synthesized output channels using the time portion of the input channel and the post-processed reconstruction parameter or the post-processed value.

Method of generating an output signal from an input signal, the input signal having at least one input channel and a sequence of quantized reconstruction parameters, the quantized reconstruction parameters being quantized in accordance with a quantization rule, and being associated with subsequent time portions of the input signal, the output signal having a number of synthesized output channels, and the number of synthesized output channels being greater than the number of input channels, comprising:

• providing the multi-channel synthesizer control signal having the smoothing control information, wherein the multi-channel synthesizer control signal representing the smoothing control information is associated to the at least one input channel;
• determining, in response to the control signal, the post-processed reconstruction parameter or the post-processed quantity derived from the reconstruction parameter for a time portion of the input signal to be processed;
• and
• reconstructing a time portion of the number of synthesized output channels using the time portion of the input channel and the post-processed reconstruction parameter or the post-processed value.