Concept for combined dynamic range compression and guided clipping prevention for audio devices

Patent metadata

Field	Value
Publication number	US-2016240204-A1
Application number	US-201615136324-A
Country	US
Kind code	A1
Filing date	Apr 22, 2016
Priority date	Oct 22, 2013
Publication date	Aug 18, 2016
Grant date	—

Abstract

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.

First claim

1 . Audio encoder for producing an audio bitstream comprising one or more audio channels and/or one or more audio objects, the audio encoder comprising a metadata encoder for producing a metadata bitstream, the audio encoder being configured:
to receive at least one dynamic range control gain sequence for an audio frame comprising one or more dynamic range control gains for a dynamic range control stage of an audio decoder; to receive at least one guided clipping prevention gain sequence for the audio frame comprising one or more guided clipping prevention gains for a guided clipping prevention stage of the audio decoder; and to incorporate at least one of said dynamic range control gain sequences and at least one of said guided clipping prevention gain sequences into the metadata bitstream.

2 . Audio encoder according to claim 1 , wherein the metadata encoder is configured to receive at least two dynamic range control gain sequences for the same audio frame comprising different dynamic range control gains, and to incorporate the at least two dynamic range control gain sequences comprising different dynamic range control gains into the metadata bitstream.

3 . Audio encoder according to claim 1 , wherein the metadata encoder is configured to receive a dynamic range control gain sequence comprising at least two dynamic range control gains related to different audio channels and/or to different audio objects, and to incorporate the dynamic range control gain sequence comprising at least two dynamic range control gains related to different audio channels and/or to different audio objects and, optionally, the relationships of the dynamic range control gains to the audio channels and/or the audio objects into the metadata bitstream.

4 . Audio encoder according to claim 1 , wherein the metadata encoder is configured to receive a dynamic range control gain sequence comprising at least two dynamic range control gains related to different frequency bands of the audio decoder, and to incorporate the dynamic range control gain sequence comprising at least two dynamic range control gains related to different frequency bands of the decoder and, optionally, the relationships of the dynamic range control gains to the frequency bands of the decoder into the metadata bitstream.

5 . Audio encoder according to claim 1 , wherein the metadata encoder is configured to receive at least two guided clipping prevention gain sequences comprising different guided clipping prevention gains, and to incorporate the at least two guided clipping prevention gain sequences comprising the different guided clipping prevention gains into the metadata bitstream.

6 . Audio encoder according to claim 1 , wherein each dynamic range control sequence is related to one of the guided clipping prevention gain sequences, wherein the metadata encoder is configured to incorporate relationships between the dynamic range control sequences and the guided clipping prevention gain sequences into the metadata bitstream.

7 . Audio encoder according to claim 1 , wherein the metadata encoder is configured to receive a guided clipping prevention gain sequence comprising at least two guided clipping prevention gains related to different audio channels and/or to different audio objects, and to incorporate the guided clipping prevention gain sequence comprising at least two guided clipping prevention gains related to different audio channels and/or to different audio objects and, optionally, the relationships of the guided clipping prevention gains to the audio channels and/or the audio objects into the metadata bitstream.

8 . Method for operating an audio encoder for producing an audio bitstream comprising one or more audio channels and/or one or more audio objects, the audio encoder comprising a metadata encoder for producing a metadata bitstream, the method comprising
receiving, on the part of the metadata encoder, at least one dynamic range control gain sequence comprising one or more dynamic range control gains for a dynamic range control stage of an audio decoder; receiving, on the part of the metadata encoder, at least one guided clipping prevention gain sequence comprising one or more guided clipping prevention gains for a guided clipping prevention stage of the audio decoder; and including, on the part of the metadata encoder, at least one of said dynamic range control gain sequences and at least one of said guided clipping prevention gain sequences into the metadata bitstream.

9 . A non-transitory digital storage medium having a computer program stored thereon to perform the method for operating an audio encoder for producing an audio bitstream comprising one or more audio channels and/or one or more audio objects, the audio encoder comprising a metadata encoder for producing a metadata bitstream, the method comprising:
receiving, on the part of the metadata encoder, at least one dynamic range control gain sequence comprising one or more dynamic range control gains for a dynamic range control stage of an audio decoder; receiving, on the part of the metadata encoder, at least one guided clipping prevention gain sequence comprising one or more guided clipping prevention gains for a guided clipping prevention stage of the audio decoder; and including, on the part of the metadata encoder, at least one of said dynamic range control gain sequences and at least one of said guided clipping prevention gain sequences into the metadata bitstream, when said computer program is run by a computer.

10 . Audio decoder for decoding an audio bitstream and a metadata bitstream related to the audio bitstream, which are produced in particular by an audio encoder for producing an audio bitstream comprising one or more audio channels and/or one or more audio objects, the audio encoder comprising a metadata encoder for producing a metadata bitstream, the audio encoder being configured:
to receive at least one dynamic range control gain sequence for an audio frame comprising one or more dynamic range control gains for a dynamic range control stage of an audio decoder; to receive at least one guided clipping prevention gain sequence for the audio frame comprising one or more guided clipping prevention gains for a guided clipping prevention stage of the audio decoder; and to incorporate at least one of said dynamic range control gain sequences and at least one of said guided clipping prevention gain sequences into the metadata bitstream,
the audio decoder comprising:
an audio processing chain configured to receive a decoded audio signal derived from the audio bitstream and to adjust characteristics of an audio output signal of the audio processing chain, the audio processing 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 of 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.

11 . Audio decoder according to claim 10 , wherein the metadata decoder is configured to extract from the metadata bitstream at least two dynamic range control gain sequences for the same audio frame comprising different dynamic range control gains.

12 . Audio decoder according to claim 10 , wherein the metadat

Assignees

• Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E V

Inventors

• Kuech Fabian
• Uhle Christian
• Kratschmer Michael
• Neugebauer Bernhard
• Meier Michael
• Borsum Arne

Classifications

• G10L21/034 Primary

  Automatic adjustment · CPC title

• H03G11/008

  of digital or coded signals · 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

• G10L19/018

  Audio watermarking, i.e. embedding inaudible data in the audio signal · CPC title

• G06F3/165

  Management of the audio stream, e.g. setting of volume, audio stream path · CPC title