Audio encoder, method for providing an encoded representation of an audio information, computer program and encoded audio representation using immediate playout frames

Patent metadata

Field	Value
Publication number	US-12573409-B2
Application number	US-202418582428-A
Country	US
Kind code	B2
Filing date	Feb 20, 2024
Priority date	Aug 19, 2021
Publication date	Mar 10, 2026
Grant date	Mar 10, 2026

Abstract

An audio encoder is disclosed for providing an encoded representation of an audio information encodes a sequence of audio frames. The audio encoder provides one or more immediate playout frames including a representation of a current audio frame, preceding the current audio frame. The audio encoder provides the representations of the current frame and of the one or more audio frames preceding the current audio frame, such that these representations are decodable using a same decoder configuration. The audio encoder provides the representations of the one or more audio frames preceding the current audio frame, which are included into the immediate playout frame, using a modified encoding functionality, which encodes an audio frame using a smaller number of bits than a normal encoding functionality, which is used for the encoding of the current audio frame.

First claim

What is claimed:

1 . An audio encoder for providing an encoded representation of an audio information on the basis of an input audio information,
wherein the audio encoder is configured to encode a sequence of audio frames, wherein the audio encoder is configured to provide one or more immediate playout frames comprising a representation of a current audio frame and encoded representations of one or more audio frames preceding the current audio frame, wherein the audio encoder is configured to provide the representation of the current frame and the representations of the one or more audio frames preceding the current audio frame such that the representation of the current frame and the representations of the one or more audio frames preceding the current audio frame are decodable using a same decoder configuration, and wherein the audio encoder is configured to provide the representations of the one or more audio frames preceding the current audio frame, which are included into the immediate playout frame, using a modified encoding functionality which is adapted to encode an audio frame using a smaller number of bits than a normal encoding functionality which is used for the encoding of the current audio frame.

2 . The audio encoder according to claim 1 , wherein the audio encoder is configured to use a modified encoding functionality, in which a bitrate setting or a bitrate limit is reduced when compared to the normal encoding functionality, for providing the representations of the one or more audio frames preceding the current audio frame.

3 . The audio encoder according to claim 1 , wherein the audio encoder is configured to use the bitrate setting or bitrate limit for deciding how many bits are allocated to an encoding of different spectral values.

4 . The audio encoder according to claim 1 , wherein the audio encoder is configured to leave encoding parameters, a change of which would result in a change of a decoder configuration unchanged between the encoding of the current frame and the encoding of the one or more audio frames preceding the current audio frame.

5 . The audio encoder according to claim 1 , wherein the audio encoder is configured to use a modified encoding functionality, in which a number of bits available for a quantization or for an encoding of one or more parameters is reduced or limited when compared to normal encoding functionality, for providing the representations of the one or more audio frames preceding the current audio frame.

6 . The audio encoder according to claim 1 , wherein the audio encoder is configured to use a modified encoding functionality, in which a coarser quantization of a MDCT spectrum is used when compared to the normal encoding functionality, for providing the representations of the one or more audio frames preceding the current audio frame.

7 . The audio encoder according to claim 1 , wherein:
the audio encoder is configured to change a global gain parameter, in order to acquire a coarser quantization, when using the modified encoding functionality; and/or the audio encoder is configured to use a modified encoding functionality, in which a masking threshold acquired using a psychoacoustic model is changed to acquire a coarser quantization, for providing the representations of the one or more audio frames preceding the current audio frame.

8 . The audio encoder according to claim 1 , wherein the audio encoder is configured to use a modified encoding functionality, and a bandwidth extension bit load is reduced, for providing the representations of the one or more audio frames preceding the current audio frame.

9 . The audio encoder according to claim 1 , wherein the audio encoder is configured to use a modified encoding functionality, and wherein:
a spectral band replication bit load is reduced, for providing the representations of the one or more audio frames preceding the current audio frame; and/or a plurality of spectral band replication parameters are set to a predetermined value which allows for a reduction or for a minimization of a number of bits required for an encoding of the spectral band replication parameters, for providing the representations of the one or more audio frames preceding the current audio frame.

10 . The audio encoder according to claim 1 , wherein the audio encoder is configured to use a modified encoding functionality, and wherein:
a number of spectral band replication bands or a number of spectral band replication envelopes is reduced, for providing the representations of the one or more audio frames preceding the current audio frame; and/or a frequency resolution of spectral band replication data is reduced, for providing the representations of the one or more audio frames preceding the current audio frame.

11 . The audio encoder according to claim 1 , wherein the audio encoder is configured to use a modified encoding functionality, and wherein:
a bit load in a UsacSbrData( ) syntax element is reduced, for providing the representations of the one or more audio frames preceding the current audio frame, while keeping spectral band replication parameters which are part of an usacConfig( ) syntax element and/or of a SbrConfig( ) syntax element unchanged; and/or a multi-channel encoding bit load is reduced, for providing the representations of the one or more audio frames preceding the current audio frame.

12 . The audio encoder according to claim 1 , wherein the audio encoder is configured to use a modified encoding functionality, and wherein:
a transform-coded excitation linear-prediction domain encoding is used instead of an ACELP linear predication domain encoding, for providing the representations of the one or more audio frames preceding the current audio frame; and/or a transform-coded excitation linear-prediction domain encoding with a coarser quantization is used instead of a transform-coded excitation linear-prediction domain encoding with a finer quantization, for providing the representations of the one or more audio frames preceding the current audio frame.

13 . The audio encoder according to claim 1 , wherein the audio encoder is configured to use a modified encoding functionality, and wherein:
a time domain resolution is reduced, for providing the representations of the one or more audio frames preceding the current audio frame; and/or a usage of multiple TCX windows within a single audio frame is avoided, for providing the representations of the one or more audio frames preceding the current audio frame.

14 . The audio encoder according to claim 1 , wherein the audio encoder is configured to use a modified encoding functionality, and wherein:
a single long TCX window is used instead of 2 medium sized TCX windows, and/or in which a single long TCX window is used instead of 4 short TCX windows, or in which a single long TCX window is used instead of a plurality of shorted TCX windows, for providing the representations of the one or more audio frames preceding the current audio frame; and/or a usage of a plurality of short MDCT transform windows within a single audio frame is avoided, for providing the representations of the one or more audio frames preceding the current audio frame.

15 . The audio encoder according to claim 1 , wherein the audio encoder is configured to use a modified encoding functionality, and wherein
a single long MDCT transform window is used instead a plurality of shorter MDCT transform windows, for providing the representations of the one or more audio frames preceding the current audio frame; and/or; a “START_STOP” MDCT transform window is used instead of an “E

Assignees

• Fraunhofer Ges Forschung

Inventors

• Neuendorf Max
• Rettelbach Nikolaus
• Mittag Christina
• Richter Daniel
• Deniau Agathe
• Aslam Wahaj
• Hofmann Ingo
• Herrmann Bernd

Classifications

• G10L2019/0001

  Codebooks · CPC title

• G10L19/12

  the excitation function being a code excitation, e.g. in code excited linear prediction [CELP] vocoders · CPC title

• G10L19/032

  Quantisation or dequantisation of spectral components · CPC title

• G10L19/002 Primary

  Dynamic bit allocation (for perceptual audio coders G10L19/032) · CPC title

• G10L19/167 Primary

  Audio streaming, i.e. formatting and decoding of an encoded audio signal representation into a data stream for transmission or storage purposes · CPC title