摘要:
An audio decoder comprises a background noise estimator that is configured to update a parametric background noise estimate during an active phase. It further comprises a background noise generator configured to synthesize an audio signal during an inactive phase.
摘要:
An audio encoder (100) for encoding segments of coefficients, the segments of coefficients representing different time or frequency resolutions of a sampled audio signal, the audio encoder (100) comprising a processor (110) for deriving a coding context for a currently encoded coefficient of a current segment based on a previously encoded coefficient of a previous segment, the previously encoded coefficient representing a different time or frequency resolution than the currently encoded coefficient. The audio encoder (100) further comprises an entropy encoder (120) for entropy encoding the current coefficient based on the coding context to obtain an encoded audio stream.
摘要:
An apparatus for encoding comprises a first domain converter (510), a switchable bypass (50), a second domain converter (410), a first processor (420) and a second processor (520) to obtain an encoded audio signal having different signal portions represented by coded data in different domains, which have been coded by different coding algorithms. Corresponding decoding stages in the decoder together with a bypass for bypassing a domain converter allow the generation of a decoded audio signal with high quality and low bit rate.
摘要:
An audio decoder (100;200;300) for providing a decoded audio information (112;212;312) on the basis of an encoded audio information (110;210;310), the audio decoder comprises a linear-prediction-domain decoder (120;220;320) configured to provide a first decoded audio information (122;222;322; S C (n)) on the basis of an audio frame encoded in a linear prediction domain, a frequency domain decoder (130;230;330) configured to provide a second decoded audio information (132;232;332; S M (n)) on the basis of an audio frame encoded in a frequency domain, and a transition processor (140;240;340).The transition processor is configured to obtain a zero-input-response (150; 256;348) of a linear predictive filtering(148; 254; 346), wherein an initial state (146;252;344) of the linear predictive filtering is defined in dependence on the first decoded audio information and the second decoded audio information. The transition processor is also configured to modify the second decoded audio information (132; 232;332;S M (n)), which is provided on the basis of an audio frame encoded in the frequency domain following an audio frame encoded in the linear prediction domain, in dependence on the zero-input-response, to obtain a smooth transition between the first decoded audio information (S C (n)) and the modified second decoded audio information ( S M ^ n ).
摘要:
An encoder for providing an audio stream on the basis of a transform-domain representation of an input audio signal comprises a quantization error calculator configured to determine a multi-band quantization error over a plurality of frequency bands of the input audio signal for which separate band gain information is available. The encoder also comprises an audio stream provider configured to provide the audio stream such that the audio stream comprises an information describing an audio content of the frequency bands and an information describing the multi-band quantization error. A decoder for providing a decoded representation of an audio signal on the basis of an encoded audio stream representing spectral components of frequency bands of the audio signal comprises a noise filler configured to introduce noise into spectral components of a plurality of frequency bands to which separate frequency band gain information is associated on the basis of a common multi-band noise intensity value.
摘要:
A signal manipulator for manipulating an audio signal having a transient event may comprise a transient remover (100), a signal processor (110) and a signal inserter (120) for inserting a time portion in a processed audio signal at a signal location where the transient event was removed before processing by said transient remover, so that a manipulated audio signal comprises a transient event not influenced by the processing, whereby the vertical coherence of the transient event is maintained instead of any processing performed in the signal processor (110), which would destroy the vertical coherence of a transient.
摘要:
A signal manipulator for manipulating an audio signal having a transient event may comprise a transient remover (100), a signal processor (110) and a signal inserter (120) for inserting a time portion in a processed audio signal at a signal location where the transient event was removed before processing by said transient remover, so that a manipulated audio signal comprises a transient event not influenced by the processing, whereby the vertical coherence of the transient event is maintained instead of any processing performed in the signal processor (110), which would destroy the vertical coherence of a transient.