摘要:
The invention provides a concept for combined dynamic range compression and guided clipping prevention for audio devices. An audio decoder for decoding an audio bitstream and a metadata bitstream related to the audio bitstream according to the concept includes an audio processing chain including a plurality of adjustment stages including a dynamic range control stage for adjusting a dynamic range of the audio output signal and a guided clipping prevention stage for preventing clipping of the audio output signal; and a metadata decoder configured to receive the metadata bitstream and to extract dynamic range control gain sequences and guided clipping prevention gain sequences from the metadata bitstream, at least a part of the dynamic range control gain sequences being supplied to the dynamic range control stage, and at least a part of the guided clipping prevention gain sequences being supplied to the guided clipping prevention stage.
摘要:
An audio signal decoder (100) for providing a decoded audio signal representation on the basis of an encoded audio signal representation comprises a decoder preprocessing stage (110) for obtaining a plurality of frequency band signals from the encoded audio signal representation, a clipping estimator (120), a level shifter (130), a frequency-to-time-domain converter (140), and a level shift compensator (150). The clipping estimator (120) analyzes the encoded audio signal representation and/or side information relative to a gain of the frequency band signals in order to determine a current level shift factor. The level shifter (130) shifts levels of the frequency band signals according to the level shift factor. The frequency-to-time-domain converter (140) converts the level shifted frequency band signals into a time-domain representation. The level shift compensator (150) acts on the time-domain representation for at least partly compensating a corresponding level shift and for obtaining a substantially compensated time-domain representation.
摘要:
An audio signal decoder (100) for providing a decoded audio signal representation on the basis of an encoded audio signal representation comprises a decoder preprocessing stage (110) for obtaining a plurality of frequency band signals from the encoded audio signal representation, a clipping estimator (120), a level shifter (130), a frequency-to-time-domain converter (140), and a level shift compensator (150). The clipping estimator (120) analyzes the encoded audio signal representation and/or side information relative to a gain of the frequency band signals in order to determine a current level shift factor. The level shifter (130) shifts levels of the frequency band signals according to the level shift factor. The frequency-to-time-domain converter (140) converts the level shifted frequency band signals into a time-domain representation. The level shift compensator (150) acts on the time-domain representation for at least partly compensating a corresponding level shift and for obtaining a substantially compensated time-domain representation.
摘要:
The invention provides a concept for combined dynamic range compression and guided clipping prevention for audio devices. An audio decoder for decoding an audio bitstream and a metadata bitstream related to the audio bitstream according to the concept comprises an audio processing chain configured to receive a decoded audio signal derived from the audio bitstream and to adjust characteristics of the audio signal in order to produce an audio output signal, the audio adjustment chain comprising a plurality of adjustment stages including a dynamic range control stage for adjusting a dynamic range of the audio output signal and a guided clipping prevention stage for preventing clipping of the audio output signal; and a metadata decoder configured to receive the metadata bitstream and to extract dynamic range control gain sequences and guided clipping prevention gain sequences from the metadata bitstream, at least a part of the dynamic range control gain sequences being supplied to the dynamic range control stage, and at least a part of the guided clipping prevention gain sequences being supplied to the guided clipping prevention stage.
摘要:
An apparatus (100) for downmixing three or more audio input channels to obtain two or more audio output channels is provided. The apparatus (100) comprises a receiving interface (110) for receiving the three or more audio input channels and for receiving side information. Moreover, the apparatus (100) comprises a downmixer (120) for downmixing the three or more audio input channels depending on the side information to obtain the two or more audio output channels. The number of the audio output channels is smaller than the number of the audio input channels. The side information indicates a characteristic of at least one of the three or more audio input channels, or a characteristic of one or more sound waves recorded within the one or more audio input channels, or a characteristic of one or more sound sources which emitted one or more sound waves recorded within the one or more audio input channels.
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.