Post-encoding Bitrate Reduction for Plenary Audio Files
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Solution Overview
Problem
Traditional audio compression techniques are not scalable, making it difficult to adjust bitrates for different applications and devices, leading to suboptimal audio quality and increased computational requirements for real-time processing.
Innovation Solution
A method for post-encoding bitrate reduction that processes a single plenary file containing multiple audio objects, allowing for fine-grained scalability by truncating bits from encoded frames while maintaining decoding capability, without the need for re-encoding, to generate scaled compressed bitstreams suitable for various bitrate requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional audio compression techniques are used with fixed bitrate encoding, then the encoding process is simple and straightforward, but the system lacks scalability to adjust bitrates for different applications and devices
Solution Approach 1:
The patent applies preliminary action by encoding audio objects at multiple bitrates in advance during the initial encoding phase. This creates a scalable bitstream structure where different bitrate versions are pre-prepared, allowing later selection without re-encoding. The high-bitrate version serves as a plenary file that can be selectively down-scaled to lower bitrates based on network conditions and device capabilities.
Solution Approach 2:
The patent segments the audio signal into multiple independent audio objects, each of which can be encoded separately at different bitrates. This segmentation allows selective encoding and scaling of individual audio objects based on their importance and the available bandwidth, enabling fine-grained bitrate control while maintaining overall audio quality.
2Adaptability or versatility
If difference coding is used to create scalable bitstreams, then bitrate scalability is achieved, but the computational intensity requires significant processing power for real-time performance
Solution Approach 1:
The patent eliminates the need for complex real-time analysis by performing all necessary encoding work in advance. The scalable bitstream is constructed during initial encoding with pre-calculated bit allocations for different bitrate scenarios, removing the computational burden from real-time operations and enabling lightweight bitrate adjustment later.
Solution Approach 2:
The patent creates multiple copies of the audio signal encoded at different bitrates during the initial encoding phase. These pre-encoded versions serve as templates that can be selectively transmitted without requiring real-time compression or analysis, significantly reducing processing power requirements during playback.
3Adaptability or versatility
If layered scalable bitstream encoding is used, then a range of scalable bitrates is achieved, but limited scalability range and resolution make it unsuitable for many applications
Solution Approach 1:
The patent changes the fundamental parameter of how scalability is achieved by moving from layered encoding with fixed resolution steps to independent audio object encoding where bitrate can be continuously adjusted. Each audio object can be encoded at any bitrate within a wide range, providing fine-grained scalability control without the resolution limitations of layered approaches.
Solution Approach 2:
The patent creates a universal encoding framework that can serve multiple functions: high-bitrate versions for quality-critical applications, low-bitrate versions for bandwidth-constrained scenarios, and selective encoding of individual audio objects based on their importance. This multi-functional approach replaces the need for multiple specialized compression techniques.
4Quantity of substance
If bitrate reduction is achieved by recoding or decompressing and recompressing, then lower bitrate is obtained, but the process is time-consuming and computationally intensive
Solution Approach 1:
The patent performs all bitrate reduction work in advance during the initial encoding phase, creating a scalable bitstream that contains pre-computed versions at different bitrates. This eliminates the need for time-consuming recoding or decompression-recompression operations later, as the lower-bitrate versions are already prepared and can be transmitted immediately.
Data Source
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AI summary
A post-encoding bitrate reduction method for generating one more scaled compressed bitstreams from a single encoded plenary file. The plenary file contains multiple audio object files that were encoded separately using a scalable encoding process having fine-grained scalability that ranks bits in each data frame of the encoded audio object files in an order of psychoacoustic importance to human hearing. The plenary file is generated at the plenary bitrate by combining the plurality of independently encoded audio object files and corresponding hierarchical metadata. A first scaled compressed bitstream is constructed at a first target bitrate from the plenary file, and a second scaled compressed bitstream is constructed at a second target bitrate from the plenary file such that multiple scaled bitstreams at different target bitrates are obtained from the single plenary file without any re-encoding of the plurality of encoded audio object files. The first target bitrate and the second target bitrate are different from each other and are both less than the plenary bitrate.