Method and System for Inter-Channel Coding
AssigneesDolby Laboratories Licensing Corporation, Dolby International AB
InventorsJanusz KLEJSA, SR., Roy M. FEJGIN, Mark S. VINTON
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Abstract
A method for performing inter-channel encoding of a multi-channel audio signal comprising channel signals for N channels, with N being an integer, with N>1, is described. The method comprises determining a basic graph comprising the N channels as nodes and comprising directed edges between at least some of the N channels. Furthermore, the method comprises determining an inter-channel coding graph from the basic graph, such that the inter-channel coding graph is a directed acyclic graph, and such that a cumulated a cumulated cost of the signals of the nodes of the inter-channel coding graph is reduced.
Claims20
1) A method for performing inter-channel encoding of a multi-channel audio signal comprising channel signals for N channels, with N>1;
- wherein the method comprises,
- determining a basic graph comprising the N channels as nodes and comprising directed edges between at least some of the N channels;
- wherein a directed edge from a source channel to a target channel indicates that the channel signal of the target channel is predicted from the channel signal of the source channel, thereby leading to a residual signal for the target channel as a prediction residual;
- wherein a directed edge indicates a cost associated with coding the residual signal of the target channel;
- determining an inter-channel coding graph from the basic graph, such that
- the inter-channel coding graph is a directed acyclic graph;
- and
- a cumulated cost associated with coding the signals of the nodes of the inter-channel coding graph is reduced compared to a cumulated cost associated with independent coding of the channel signals of the multi-channel audio signal;
- and
- applying the inter-channel coding graph for inter-channel encoding of at least one channel of the multi-channel audio signal.
15) A method for encoding an inter-channel coding graph which is indicative of inter-channel coding of channels of a multi-channel audio signal into a bitstream;
- wherein the inter-channel coding graph comprises nodes that represent the channels of the multi-channel audio signal and directed edges that represent coding dependencies between the channels;
- wherein the method comprises,
- sorting the channels of the inter-channel coding graph to provide a topologically sorted graph, such that
- the channels are assigned to a sequence of positions;
- a channel assigned to a first position from the sequence of positions can be encoded independently;
- and
- for each subsequent position from the sequence of positions, a channel assigned to this position can be encoded independently or can be encoded in dependence of one or more channels assigned to one or more previous positions;
- encoding at least one of the topologically sorted graph and the multi-channel audio signal into a bitstream, such that a decoder is enabled to decode the channels of the multi-channel audio signal in accordance to the positions assigned to the channels.
19) A method for performing inter-channel encoding of one or more dependent audio channels of a dependent presentation in dependence of a main audio channel of a main presentation;
- wherein the method comprises,
- determining a basic graph comprising the one or more dependent channels and the main channel as nodes and comprising directed edges between at least some of the channels;
- wherein a directed edge between a source channel and a target channel indicates that the channel signal of the target channel is predicted from the channel signal of the source channel, thereby leading to a residual signal for the target channel as a prediction residual;
- wherein a directed edge indicates a cost associated with coding the residual signal of the target channel;
- wherein the basic graph comprises one or more directed edges having the main channel as a source channel;
- and wherein the basic graph does not comprise any directed edges having the main channel as a target channel;
- and
- determining an inter-channel coding graph for the dependent presentation from the basic graph, such that the inter-channel coding graph is a directed acyclic graph;
- and
- applying the inter-channel coding graph for inter-channel encoding of at least one dependent audio channel.
Dependencies are inferred from the claim text.