Efficient coding of audio scenes comprising audio objects

A method for reconstructing audio objects based on a data stream, comprising:

• receiving a data stream comprising M downmix signals which are combinations of N audio objects, wherein N>1 and M≦N, and time-variable side information including parameters which allow reconstruction of a set of audio objects formed on the basis of the N audio objects from the M downmix signals;
• and
• reconstructing, based on the M downmix signals and the side information, said set of audio objects formed on the basis of the N audio objects,
• wherein the data stream corresponds to a plurality of time frames, wherein the data stream comprises a plurality of side information instances, wherein the data stream further comprises, for each side information instance, transition data including two independently assignable portions which in combination define a point in time to begin a transition from a current reconstruction setting to a desired reconstruction setting specified by the side information instance, and a point in time to complete the transition, and wherein for each specific side information instance of the plurality of side information instances:
• the point in time defined by the transition data of the specific side information instance for beginning a transition corresponds to a first of the plurality of time frames, wherein the point in time defined by the transition data of the specific side information instance for completing a transition corresponds to a second of the plurality of time frames,
• the second time frame is either the same as the first time frame or subsequent to the first time frame, and
• wherein reconstructing said set of audio objects formed on the basis of the N audio objects comprises:
• performing reconstruction according to a current reconstruction setting;
• beginning, at a point in time defined by the transition data for a side information instance, a transition from the current reconstruction setting to a desired reconstruction setting specified by the side information instance;
• and
• completing the transition at a point in time defined by the transition data for the side information instance.

A decoder for reconstructing audio objects based on a data stream, comprising:

• a receiving component configured to receive a data stream comprising M downmix signals which are combinations of N audio objects, wherein N>1 and M≦N, and time-variable side information including parameters which allow reconstruction of a set of audio objects formed on the basis of the N audio objects from the M downmix signals;
• and
• a reconstructing component configured to reconstruct, based on the M downmix signals and the side information, the set of audio objects formed on the basis of the N audio objects,
• wherein the data stream corresponds to a plurality of time frames, wherein the data stream comprises a plurality of side information instances, wherein the data stream further comprises, for each side information instance, transition data including two independently assignable portions which in combination define a point in time to begin a transition from a current reconstruction setting to a desired reconstruction setting specified by the side information instance, and a point in time to complete the transition, and wherein for each specific side information instance of the plurality of side information instances:
• the point in time defined by the transition data of the specific side information instance for beginning a transition corresponds to a first of the plurality of time frames, wherein the point in time defined by the transition data of the specific side information instance for completing a transition corresponds to a second of the plurality of time frames,
• the second time frame is either the same as the first time frame or subsequent to the first time frame and
• wherein the reconstructing component is configured to reconstruct said set of audio objects formed on the basis of the N audio objects by at least:
• performing reconstruction according to a current reconstruction setting;
• beginning, at a point in time defined by the transition data for a side information instance, a transition from the current reconstruction setting to a desired reconstruction setting specified by the side information instance;
• and
• completing the transition at a point in time defined by the transition data for the side information instance.

A method for transcoding side information encoded together with M audio signals in a data stream, wherein the method comprises:

• receiving a data stream corresponding to a plurality of time frames;
• extracting, from the data stream, M audio signals and associated time-variable side information including parameters which allow reconstruction of a set of audio objects from the M audio signals, wherein M≧1, and wherein the extracted side information includes:
• a plurality of side information instances specifying respective desired reconstruction settings for reconstructing the audio objects, and
• for each side information instance, transition data including two independently assignable portions which in combination define a point in time to begin a transition from a current reconstruction setting to the desired reconstruction setting specified by the side information instance, and a point in time to complete the transition, and wherein for each specific side information instance of the plurality of side information instances:
• the point in time defined by the transition data of the specific side information instance for beginning a transition corresponds to a first of the plurality of time frames, wherein the point in time defined by the transition data of the specific side information instance for completing a transition corresponds to a second of the plurality of time frames,
• the second time frame is either the same as the first time frame or subsequent to the first time frame;
• generating one or more additional side information instances specifying substantially the same reconstruction setting as a side information instance directly preceding or directly succeeding the one or more additional side information instances;
• and
• including the M audio signals and the side information in a transcoded data stream.