AAC Bitstream Speaker Mapping for Extended Multichannel Audio
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Solution Overview
Problem
Current multi-channel audio encoding techniques, such as those based on the MPEG-2AAC and MPEG-4AAC standards, face difficulties in achieving high-quality realistic sound, particularly in extending channels beyond the traditional 5.1 configuration, as they lack sufficient information for channel extension in the vertical direction and appropriate downmixing information.
Innovation Solution
The proposed solution involves a decoding and encoding device that includes identification information detection and encoding units to read and encode specific information within an encoded bit stream, allowing for the identification and storage of speaker arrangement data, which enables the decoding device to correctly interpret and reproduce audio data in multiple channel configurations, including 6.1 and 7.1 channels, by using byte alignment and CRC checks to validate the information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multi-channel encoding based on MPEG-2AAC or MPEG-4AAC standards is used, then encoding compatibility with existing standards is maintained, but the ability to extend channels in the vertical direction and achieve high-quality realistic sound is insufficient
Solution Approach 1:
The speaker arrangement information is segmented into identification information (for validating authenticity) and predetermined information (for specifying channel configurations). This segmentation allows the system to separately handle authentication and data interpretation, enabling extended channel configurations while maintaining compatibility with existing standards through the identification information validation mechanism.
Solution Approach 2:
The patent introduces an intermediary data structure containing identification information and predetermined information that acts as a bridge between existing MPEG standards and extended channel configurations. This intermediary layer allows the system to interpret speaker arrangement data for extended channels (beyond traditional 5.1) while maintaining compatibility with existing decoding standards through the identification information validation process.
2Measurement precision
If identification information and predetermined information are stored in the encoded bit stream, then speaker arrangement data can be accurately interpreted for channel extension, but the complexity of the encoding and decoding process increases
Solution Approach 1:
The identification information is generated and stored in advance during the encoding process, allowing the decoding device to quickly validate the authenticity of speaker arrangement information without complex real-time analysis. This preliminary action simplifies the decoding process by enabling fast authentication before detailed interpretation of the predetermined information.
Solution Approach 2:
The identification information serves as a feedback mechanism that allows the decoding device to validate the authenticity of speaker arrangement information. This feedback loop ensures accurate interpretation of channel configurations while maintaining a relatively simple decoding process, as the validation step provides clear pass/fail information without requiring complex analysis.
3Reliability
If CRC check information is calculated and stored to validate predetermined information, then information integrity is ensured, but the amount of data to be processed and stored increases
Solution Approach 1:
The CRC check information is applied locally to specific predetermined information blocks rather than the entire bit stream. This localized application ensures information integrity for critical speaker arrangement data while minimizing the overall data volume increase, as the CRC checks are only performed on relevant segments containing channel configuration information.
Data Source
AI summary
The present technique relates to a decoding device, a decoding method, an encoding device, an encoding method, and a program which can obtain a high-quality realistic sound.The encoding device stores speaker arrangement information in a comment region in a PCE of an encoded bit stream and stores a synchronous word and identification information in the comment region such that other public comments and the speaker arrangement information stored in the comment region can be distinguished from each other. When an encoded bit stream is decoded, it is determined whether the speaker arrangement information is stored on the basis of the synchronous word and the identification information stored in the comment region. Audio data included in the encoded bit stream is output according to the arrangement of the speakers corresponding to the determination result. The present technique can be applied to an encoding device.