Multi-Room Multi-Channel Audio Synchronization With LC3 and NACK
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current audio synchronization solutions in multi-room and multi-channel audio systems face high audio delay and poor synchronization due to high algorithm delay in encoding and decoding processes, and network instability leading to increased latency.
Innovation Solution
A multi-room multi-channel audio synchronization method using low-latency LC3 encoding, UDP with NACK retransmission, and distributed clock synchronization mechanisms, along with channel grouping and dynamic delay compensation, to achieve precise synchronization across devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If AAC or MP3 encoding technologies are used to ensure audio signal synchronization, then compression rate is improved, but encoding and decoding delay increases due to accumulated audio frame processing requirements
Solution Approach 1:
The patent changes the encoding parameters by switching from traditional AAC/MP3 codecs to the LC3 codec, which uses a different compression algorithm that processes fewer audio frames while maintaining quality. This parameter change (codecs) directly reduces the accumulated frame processing delay while preserving compression efficiency
2Reliability
If TCP protocol is used to ensure reliable data transmission, then transmission reliability is improved, but latency increases significantly when the network is unstable due to congestion control and retransmission mechanisms
Solution Approach 1:
The patent introduces an intermediary mechanism (NACK retransmission) that selectively retransmits only lost or erroneous audio packets rather than using TCP's comprehensive congestion control and retransmission. This intermediary approach maintains reliability for critical audio data while avoiding the heavy-handed latency-inducing mechanisms of full TCP protocol
Solution Approach 2:
The system dynamically switches between UDP's speed and selective retransmission based on network conditions, rather than using static TCP protocol. This dynamic approach allows the system to optimize between speed and reliability in real-time, reducing latency while maintaining audio quality
3Ease of manufacture
If wireless connection is used to simplify wiring in multi-room audio systems, then ease of installation is improved, but audio synchronization performance deteriorates due to high algorithm delay and network instability
Solution Approach 1:
The patent changes key system parameters including the audio codec (to LC3), transmission protocol (to UDP with NACK), and synchronization mechanism (to PTP). These parameter changes collectively reduce the algorithmic delay and improve time synchronization, making wireless systems performant enough for multi-room audio applications
Data Source
AI summary
A multi-room multi-channel audio synchronization method, apparatus, and device and a storage medium are provided. In this method, an audio signal to be played in a primary audio device is determined, the audio signal is encoded according to channels by using a preset low-latency audio encoding strategy and audio encoding data is obtained. Next, the audio encoding data is optimized based on a User Datagram Protocol and a Negative Acknowledgment NACK retransmission mechanism to obtain audio coded sequence data packets. The audio encoding sequence data packets are controlled to be synchronously played in at least one secondary audio device by using a preset room synchronization control strategy and a channel synchronization control strategy.