Dolby International Ab

Dolby Laboratories Licensing Corporation

Tobias Friedrich

Karsten Linzmeier

Tobias R Wagenblass

Claus-Christian Spenger

Alexander Mueller

Heiko Purnhagen

Holger Hoerich

Klaus Peichl

Martin Wolters

Arijit Biswas

Robin Thesing

Stanislaw Gorlow

Michael C Ward

Jeffrey Charles Riedmiller

Leif Jonas Samuelsson

Karl Jonas Roeden

Alexander Groeschel

Jens Popp

Daniel Homm

Celine Merpillat

Jenns Popp

The present document relates to audio coding systems. In particular, the present document relates to efficient methods and systems for parametric multi-channel audio coding. An audio encoding system configured to generate a bitstream indicative of a downmix signal and spatial metadata for generating a multi-channel upmix signal from the downmix signal is described. The system comprises a downmix processing unit configured to generate the downmix signal from a multi-channel input signal; wherein the downmix signal comprises m channels and wherein the multi-channel input signal comprises n channels; n, m being integers with m<n. Furthermore, the system comprises a parameter processing unit configured to determine the spatial metadata from the multi-channel input signal. In addition, the system comprises a configuration unit configured to determine one or more control settings for the parameter processing unit based on one or more external settings; wherein the one or more external settings comprise a target data-rate for the bitstream and wherein the one or more control settings comprise a maximum data-rate for the spatial metadata.

Methods for parametric multi-channel encoding

Dialogue enhancement of an audio signal, comprising obtaining a set of time-varying parameters configured to estimate a dialogue component present in said audio signal, estimating the dialogue component from the audio signal, applying a compressor only to the estimated dialogue component, to generate a processed dialogue component, applying a user-determined gain to the processed dialogue component, to provide an enhanced dialogue component. The processing of the estimated dialogue may be performed on the decoder side or encoder side. The invention enables an improved dialogue enhancement.

Dialogue enhancement in audio codec

The present disclosure relates to the field audio coding, an in particular to an audio decoder having at least two decoding modes, and associated decoding methods and decoding software for such audio decoder. In one of the decoding modes, at least one dynamic audio object is mapped to a set of static audio objects, the set of static audio objects corresponding to a predefined speaker configuration. The present disclosure further relates to a corresponding audio encoder, and associated encoding methods and encoding software for such audio encoder.

Audio encoder and an audio decoder

The present document relates to audio coding systems. In particular, the present document relates to efficient methods and systems for parametric multi-channel audio coding. An audio encoding system configured to generate a bitstream indicative of a downmix signal and spatial metadata for generating a multi-channel upmix signal from the downmix signal is described. The system comprises a downmix processing unit configured to generate the downmix signal from a multi-channel input signal; wherein the downmix signal comprises m channels and wherein the multi-channel input signal comprises n channels; n, m being integers with m&#x3c;n. Furthermore, the system comprises a parameter processing unit configured to determine the spatial metadata from the multi-channel input signal. In addition, the system comprises a configuration unit configured to determine one or more control settings for the parameter processing unit based on one or more external settings; wherein the one or more external settings comprise a target data-rate for the bitstream and wherein the one or more control settings comprise a maximum data-rate for the spatial metadata.

A method for rendering an audio output based on an audio data stream including M audio signals, side information including a series of reconstruction instances of a reconstruction matrix C and first timing data, the side information allowing reconstruction of N audio objects from the M audio signals, and object metadata defining spatial relationships between the N audio objects. The method includes generating a synchronized rendering matrix based on the object metadata, the first timing data, and information relating to a current playback system configuration, the synchronized rendering matrix having a rendering instance for each reconstruction instance, multiplying each reconstruction instance with a corresponding rendering instance to form a corresponding instance of an integrated rendering matrix, and applying the integrated rendering matrix to the audio signals in order to render an audio output.

Integrated reconstruction and rendering of audio signals

An error-concealing audio decoding method comprises: receiving a packet comprising a set of MDCT coefficients encoding a frame of time-domain samples of an audio signal; identifying the received packet as erroneous; generating estimated MDCT coefficients to replace the set of MDCT coefficients of the erroneous packet, based on corresponding MDCT coefficients associated with a received packet directly preceding the erroneous packet; assigning signs of a first subset of MDCT coefficients of the estimated MDCT coefficients, wherein the first subset comprises such MDCT coefficients that are associated with tonal-like spectral bins, to coincide with signs of corresponding MDCT coefficients of said preceding packet; randomly assigning signs of a second subset of MDCT coefficients of the estimated MDCT coefficients, wherein the second subset comprises MDCT coefficients associated with noise-like spectral bins; replacing the erroneous packet by a concealment packet containing the estimated MDCT coefficients and the signs assigned.

MDCT-domain error concealment

An encoder () comprises a core encoder () for encoding a low frequency component of the audio signal at the signal sampling rate (fs_in) and a spectral band replication-referred to as SBR-encoding unit () for determining a plurality of SBR parameters. A plurality of the SBR parameters is determined such that a high frequency component of the audio signal can be approximated based on the low frequency component of the audio signal and the plurality of SBR parameters. A multiplexer () is adapted to generate an overall bitstream comprising the core encoded bitstream, the plurality of SBR parameters and an indication of one or more SBR encoder settings applied by the SBR encoder (); wherein the generated overall bitstream does not indicate that the core encoded bitstream has been determined by encoding the low frequency component at the signal sampling rate (fs_in).

Upsampling using oversampled SBR

The present document relates to the design of anti-aliasing and/or anti-imaging filters for resamplers using rational resampling factors. In particular, the present document relates to a method for implementing such anti-aliasing and/or anti-imaging filters with reduced computational complexity. In addition, the present document relates to further aspects of an audio encoding and decoding system, such as the phase relation between the channels of a multi-channel audio signal and/or the structure of the bitstream of an encoded audio signal.

System aspects of an audio codec

The present document relates to audio coding systems. In particular, the present document relates to efficient methods and systems for parametric multi-channel audio coding. An audio encoding system () configured to generate a bitstream () indicative of a downmix signal and spatial metadata for generating a multi-channel upmix signal from the downmix signal is described. The system () comprises a downmix processing unit () configured to generate the downmix signal from a multi-channel input signal (); wherein the downmix signal comprises m channels and wherein the multi-channel input signal () comprises n channels; n, m being integers with m&#x3c;n. Furthermore, the system () comprises a parameter processing unit () configured to determine the spatial metadata from the multi-channel input signal (). In addition, the system () comprises a configuration unit () configured to determine one or more control settings for the parameter processing unit () based on one or more external settings; wherein the one or more external settings comprise a target data-rate for the bitstream () and wherein the one or more control settings comprise a maximum data-rate for the spatial metadata.

Growing community of inventors

Nuremberg, Germany

Tobias Friedrich