Unified Audio Bitstream Encoding for DD+ and AAC Compatibility
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Solution Overview
Problem
Conventional audio encoding systems are unable to generate a single bitstream that is compatible with both Dolby Digital Plus (DD+) and AAC or HE AAC decoders, limiting cross-platform compatibility and requiring transcoding across different media delivery systems.
Innovation Solution
An audio encoding system that generates a unified bitstream compatible with both DD+ and AAC or HE AAC decoders by multiplexing one encoding format within the auxiliary data fields of the other, allowing a single bitstream to be decoded by either type of decoder without the need for demultiplexing or recombining, using a shared bitpool to optimize bit allocation between encoding subsystems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional audio encoding systems use separate encoding protocols for DD+ and AAC/HE AAC, then each protocol can be optimized for its specific decoder, but cross-platform compatibility is limited and transcoding is required
Solution Approach 1:
The patent combines two separate encoding protocols (DD+ and AAC/HE AAC) into a single unified encoding system that generates one bitstream compatible with both decoder types. The encoder integrates multiple encoding subsystems working together, sharing common components like the transform stage and quantizer, while producing encoded data that can be decoded by either DD+ or AAC/HE AAC decoders without requiring separate transcoding processes.
Solution Approach 2:
The unified encoder is designed to perform multiple functions simultaneously - it can encode audio data in formats compatible with both DD+ and AAC/HE AAC protocols through a single system. The encoded audio data generated by this universal encoder can be decoded by various types of decoders (DD+ decoders, AAC decoders, HE AAC decoders) without requiring the encoder to be specialized for a single protocol, thereby achieving multi-functionality and broad compatibility.
2Adaptability or versatility
If a unified bitstream is generated to be compatible with both DD+ and AAC/HE AAC decoders, then transcoding is eliminated and compatibility is improved, but the encoding system complexity increases
Solution Approach 1:
The unified encoder is segmented into distinct encoding subsystems - a first encoding subsystem for DD+ compatible encoding and a second encoding subsystem for AAC/HE AAC compatible encoding. Each subsystem processes audio data independently through shared transform and quantization stages, allowing the system to generate both types of encoded data within a single encoder architecture. This segmentation enables the encoder to produce a unified bitstream that contains encoded data readable by both decoder types without requiring a single monolithic complex structure.
Solution Approach 2:
The encoding subsystems are nested within a hierarchical structure where common functional blocks (transform stage, quantizer) serve multiple specialized encoding subsystems. The first and second encoding subsystems are nested within the unified encoder architecture, sharing common resources while maintaining protocol-specific processing paths. This nested organization allows the system to achieve comprehensive compatibility without proportionally increasing overall complexity, as the shared components handle the bulk of the processing work for both protocol types.
3Productivity
If separate encoding protocols are used for different decoder types, then each protocol can be independently optimized, but multiple transcoding operations are required across media delivery systems
Solution Approach 1:
The unified encoder performs preliminary action by generating a unified bitstream in advance that is pre-configured for compatibility with multiple decoder types (DD+, AAC, HE AAC). Instead of performing transcoding operations later at delivery points or playback devices, the encoder proactively creates a single bitstream that anticipates and accommodates various decoder capabilities. This preliminary unification eliminates the need for subsequent transcoding operations, saving time and improving media delivery efficiency across different platforms and devices.
Data Source
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AI summary
In a class of embodiments, an audio encoding system (typically, a perceptual encoding system that is configured to generate a single ("unified") bitstream that is compatible with (i.e., decodable by) a first decoder configured to decode audio data encoded in accordance with a first encoding protocol (e.g., the multichannel Dolby Digital Plus, or DD+, protocol) and a second decoder configured to decode audio data encoded in accordance with a second encoding protocol (e.g., the stereo AAC, HE AAC v1, or HE AAC v2 protocol). The unified bitstream can include both encoded data (e.g., bursts of data) decodable by the first decoder (and ignored by the second decoder) and encoded data (e.g., other bursts of data) decodable by the second decoder (and ignored by the first decoder). In effect, the second encoding format is hidden within the unified bitstream when the bitstream is decoded by the first decoder, and the first encoding format is hidden within the unified bitstream when the bitstream is decoded by the second decoder. The format of the unified bitstream generated in accordance with the invention may eliminate the need for transcoding elements throughout an entire media chain and/or ecosystem. Other aspects of the invention are an encoding method performed by any embodiment of the inventive encoder, a decoding method performed by any embodiment of the inventive decoder, and a computer readable medium (e.g., disc) which stores code for implementing any embodiment of the inventive method.