Ambient Higher-Order Ambisonic Coefficient Transition Encoding
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Solution Overview
Problem
Current technologies face challenges in efficiently compressing and decoding higher-order ambisonic audio data, particularly in representing and rendering soundfields independently of speaker geometry, while maintaining backward compatibility and adaptability to varying playback conditions.
Innovation Solution
The method involves determining transitions in ambient higher-order ambisonic coefficients, generating reduced vectors, and encoding transition state information in a bitstream, allowing for decoding without referencing previous frames and enabling flexible rendering across different speaker configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If ambient higher-order ambisonic coefficients are continuously updated in each frame, then the soundfield representation accuracy is improved, but the bitstream complexity and decoding dependency increase
Solution Approach 1:
The patent extracts only the essential elements needed for accurate soundfield representation by identifying specific vector elements associated with transitioning coefficients and incorporating only those into the reduced vector, rather than transmitting complete coefficient data for every frame
Solution Approach 2:
The patent segments the bitstream into frames with independent decodability, where each frame contains self-contained information about transitioning coefficients through the reduced vector and state information, eliminating dependency on previous frames while maintaining accuracy
2Ease of operation
If transition state information is encoded in the bitstream, then the decoding independence is improved, but the bitstream data volume increases
Solution Approach 1:
The patent applies local quality by providing detailed transition state information only for specific coefficients that are actually transitioning, rather than encoding state information for all coefficients in every frame, thus minimizing additional data volume while ensuring decoding independence where needed
3Loss of information
If the reduced vector includes all vector elements, then the spatial component completeness is improved, but the compression efficiency deteriorates
Solution Approach 1:
The patent extracts only the necessary vector elements that correspond to transitioning ambient higher-order ambisonic coefficients and includes them in the reduced vector, removing redundant elements to achieve compression while preserving spatial completeness for transitioning components
Solution Approach 2:
The patent applies partial action by including only the specific vector elements needed for representing transitioning coefficients rather than all elements, achieving sufficient spatial representation for the changing components without the overhead of complete vector transmission
Data Source
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AI summary
In general, techniques are described for transitioning an ambient higher order ambisonic coefficient. A device comprising a memory and a processor may be configured to perform the techniques. The processor may obtain, from a frame of a bitstream of encoded audio data, a bit indicative of a reduced vector. The reduced vector may represent, at least in part, a spatial component of a sound field. The processor may also obtain, from the frame, a bit indicative of a transition of an ambient higher-order ambisonic coefficient. The ambient higher-order ambisonic coefficient may represent, at least in part, an ambient component of the sound field. The reduced vector may include a vector element associated with the ambient higher-order ambisonic coefficient in transition. The memory may be configured to store the frame of the bitstream.