Abstract: What is described is an apparatus for post-processing an audio signal, having: a time-spectrum-converter for converting the audio signal into a spectral representation having a sequence of spectral frames; a prediction analyzer for calculating prediction filter data for a prediction over frequency within a spectral frame; a shaping filter controlled by the prediction filter data for shaping the spectral frame to enhance a transient portion within the spectral frame; and a spectrum-time-converter for converting a sequence of spectral frames having a shaped spectral frame into a time domain.

Abstract: An audio signal processor for providing ambient signal channels on the basis of an input audio signal, is configured to extract an ambient signal on the basis of the input audio signal. The signal processor is configured to distribute the ambient signal to a plurality of ambient signal channels in dependence on positions or directions of sound sources within the input audio signal, wherein a number of ambient signal channels is larger than a number of channels of the input audio signal.

Abstract: Apparatus for post-processing an audio signal, including: a converter for converting the audio signal into a time-frequency representation; a transient location estimator for estimating a location in time of a transient portion using the audio signal or the time-frequency representation; and a signal manipulator for manipulating the time-frequency representation, wherein the signal manipulator is configured to reduce or eliminate a pre-echo in the time-frequency representation at a location in time before the transient location or to perform a shaping of the time-frequency representation at the transient location to amplify an attack of the transient portion.

Abstract: An apparatus for determining a predetermined characteristic related to a spectral enhancement processing of an audio signal includes a deriver configured for obtaining a spectrum of the audio signal and for deriving a local maximum signal from the spectrum. The apparatus includes a determiner configured for determining a similarity between segments of the local maximum signal and includes a processor for providing an information indicating that the audio signal includes the predetermined characteristic dependent on an evaluation of the similarity.

Abstract: An audio signal processor for providing ambient signal channels on the basis of an input audio signal, is configured to extract an ambient signal on the basis of the input audio signal. The signal processor is configured to distribute the ambient signal to a plurality of ambient signal channels in dependence on positions or directions of sound sources within the input audio signal, wherein a number of ambient signal channels is larger than a number of channels of the input audio signal.

Abstract: A loudspeaker includes one or more drivers and at least two waveguides. The one or more drivers are arranged to emit soundwaves. The waveguides are coupled to the one or more drivers to receive the soundwaves emitted by the one or more drivers. The first of the at least two waveguides has an output position at a first position of the loudspeaker and is configured to forward the received soundwaves to the output at the first position, wherein a second of the at least two waveguides has an output position at a second position of the loudspeaker and is configured to forward the received soundwaves to the output at the second position.

Abstract: An apparatus for determining a similarity information on the basis of one or more input signals is configured to determine a zero crossing information describing a number of zero crossings in a respective portion for a plurality of portions of at least one of the one or more input signals. The apparatus is configured to perform a comparison on the basis of the zero crossing information, in order to determine the similarity information. A method for determining a similarity information and a computer program are also described. Moreover, an apparatus for determining an autocorrelation information and an apparatus for determining a cross-correlation information are based on similar considerations.

Abstract: An apparatus for determining a predetermined characteristic related to a spectral enhancement processing of an audio signal includes a deriver configured for obtaining a spectrum of the audio signal and for deriving a local maximum signal from the spectrum. The apparatus includes a determiner configured for determining a similarity between segments of the local maximum signal and includes a processor for providing an information indicating that the audio signal includes the predetermined characteristic dependent on an evaluation of the similarity.

Abstract: An apparatus for determining a predetermined characteristic related to an artificial bandwidth limitation processing of an audio signal has a slope evaluator configured for evaluating a slope of a spectrum of the audio signal to obtain a slope evaluation result. The apparatus has a frequency evaluator configured for evaluating a cut-off frequency of the spectrum of the audio signal to obtain a frequency evaluation result, and has a processor for providing an information indicating that the audio signal has the predetermined characteristic dependent on an evaluation of the slope evaluation result and an evaluation of the frequency evaluation result.

Abstract: Apparatus for post-processing an audio signal, including: a converter for converting the audio signal into a time-frequency representation; a transient location estimator for estimating a location in time of a transient portion using the audio signal or the time-frequency representation; and a signal manipulator for manipulating the time-frequency representation, wherein the signal manipulator is configured to reduce or eliminate a pre-echo in the time-frequency representation at a location in time before the transient location or to perform a shaping of the time-frequency representation at the transient location to amplify an attack of the transient portion.

Abstract: An apparatus for processing an audio signal includes a separator for separating a first portion of a spectrum of the audio signal from a second portion of the spectrum of the audio signal, the first portion having a first signal characteristic and the second portion having a second signal characteristic. The apparatus includes a first bandwidth extender for extending a bandwidth of the first portion using first parameters associated with the first signal characteristic, for obtaining a first extended portion and includes a second bandwidth extender for extending a bandwidth of the second portion using second parameters associated with the second signal characteristic, for obtaining a second extended portion. The apparatus includes a combiner configured for using the first extended portion and the second extended portion for obtaining an extended combined audio signal.

Abstract: What is described is an apparatus for post-processing an audio signal, having: a time-spectrum-converter for converting the audio signal into a spectral representation having a sequence of spectral frames; a prediction analyzer for calculating prediction filter data for a prediction over frequency within a spectral frame; a shaping filter controlled by the prediction filter data for shaping the spectral frame to enhance a transient portion within the spectral frame; and a spectrum-time-converter for converting a sequence of spectral frames having a shaped spectral frame into a time domain.

Abstract: An apparatus for determining a similarity information on the basis of one or more input signals is configured to determine a zero crossing information describing a number of zero crossings in a respective portion for a plurality of portions of at least one of the one or more input signals. The apparatus is configured to perform a comparison on the basis of the zero crossing information, in order to determine the similarity information. A method for determining a similarity information and a computer program are also described. Moreover, an apparatus for determining an autocorrelation information and an apparatus for determining a cross-correlation information are based on similar considerations.

Abstract: An apparatus for generating a plurality of loudspeaker signals from two or more audio source signals is provided. Each of the two or more audio source signals shall be reproduced in one or more of two or more sound zones, and at least one of the two or more audio source signals shall not be reproduced in at least one of the two more sound zones. An audio preprocessor is configured to modify each initial audio signal of the two or more initial audio signals depending on a signal power or a loudness of another initial audio signal of the two or more initial audio signals. A filter is configured to generate the plurality of loudspeaker signals depending on in which of the two or more sound zones the two or more audio source signals shall be reproduced and depending on in which of the two or more sound zones the two or more audio source signals shall not be reproduced.

Abstract: An apparatus for generating a stereo output signal includes a manipulation information generator being adapted to generate manipulation information depending on a first signal indication value of a first input channel and on a second signal indication value of a second input channel, and a manipulator for manipulating a combination signal based on the manipulation information to obtain a first manipulated signal as a first output channel and a second manipulated signal as a second output channel. The combination signal is a signal derived by combining the first input channel and the second input channel. Furthermore, the manipulator is configured for manipulating the combination signal in a first manner, when the first signal indication value is in a first relation to the second signal indication value, or in a different second manner, when the first signal indication value is in a different second relation to the second signal indication value.

Abstract: An apparatus for generating a stereo side signal having a first side channel and a second side channel from a stereo input signal having a first input channel and a second input channel is provided. The apparatus has a modification information generator for generating modification information based on mid-side information. Furthermore, the apparatus has a signal manipulator being adapted to manipulate the first input channel based on the modification information to obtain the first side channel and being adapted to manipulate the second input channel based on the modification information to obtain the second side channel. The modification information generator has a spectral weights generator for generating the modification information by generating a first spectral weighting factor based on a mono mid signal and on a mono side signal of the stereo input signal.

Abstract: An apparatus for generating a modified audio signal having two or more modified audio channels from an audio input signal comprising two or more audio input channels is provided. The apparatus has an information generator for generating signal-to-downmix information. The information generator is adapted to generate signal information by combining a spectral value of each of the two or more audio input channels in a first way. The information generator is adapted to generate downmix information by combining the spectral value of each of the two or more audio input channels in a second way being different from the first way. Furthermore, the information generator is adapted to combine the signal information and the downmix information to obtain signal-to-downmix information. The apparatus has a signal attenuator for attenuating the two or more audio input channels depending on the signal-to-downmix information to obtain the two or more modified audio channels.

Abstract: An apparatus for determining a measure for a perceived level of reverberation in a mix signal consisting of a direct signal component and a reverberation signal component, has a loudness model processor having a perceptual filter stage for filtering the dry signal component the reverberation signal component or the mix signal, wherein the perceptual filter stage is configured for modeling an auditory perception mechanism of an entity to obtain a filtered direct signal, a filtered reverberation signal or a filtered mix signal. The apparatus furthermore has a loudness estimator for estimating a first loudness measure using the filtered direct signal and for estimating a second loudness measure using the filtered reverberation signal or the filtered mix signal, where the filtered mix signal is derived from a superposition of the direct signal component and the reverberation signal component.

Abstract: An apparatus for generating a modified audio signal having two or more modified audio channels from an audio input signal comprising two or more audio input channels is provided. The apparatus has an information generator for generating signal-to-downmix information. The information generator is adapted to generate signal information by combining a spectral value of each of the two or more audio input channels in a first way. The information generator is adapted to generate downmix information by combining the spectral value of each of the two or more audio input channels in a second way being different from the first way. Furthermore, the information generator is adapted to combine the signal information and the downmix information to obtain signal-to-downmix information. The apparatus has a signal attenuator for attenuating the two or more audio input channels depending on the signal-to-downmix information to obtain the two or more modified audio channels.

Abstract: An apparatus for generating a stereo side signal having a first side channel and a second side channel from a stereo input signal having a first input channel and a second input channel is provided. The apparatus has a modification information generator for generating modification information based on mid-side information. Furthermore, the apparatus has a signal manipulator being adapted to manipulate the first input channel based on the modification information to obtain the first side channel and being adapted to manipulate the second input channel based on the modification information to obtain the second side channel. The modification information generator has a spectral weights generator for generating the modification information by generating a first spectral weighting factor based on a mono mid signal and on a mono side signal of the stereo input signal.