Audio Reproduction Synchronization for Multi-Format Signals

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Solution Overview

Problem

Conventional audio reproducing methods fail to synchronize plural digital audio signals with different sampling rates or coding schemes, leading to challenges in reproducing audio signals in synchronism, especially when combining surround sound and stereo sound with different channel configurations.

Innovation Solution

An audio reproducing apparatus that synchronizes plural audio signals by allocating audio reproduction time information on a common time axis, using a synchronization unit to match the sampling rates and channel configurations, and includes a sampling rate conversion unit to ensure synchronized playback, along with an output level adjustment unit to manage audio levels effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple audio signals with different sampling rates and coding schemes are reproduced independently, then each audio signal can be decoded using its own decoding unit, but the audio signals cannot be reproduced in synchronism with each other

Engineering Contradiction:

Improveability to reproduce multiple audio signals with different coding schemesVSAvoidsynchronization of audio signals

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The invention separates the audio reproduction system into independent decoding units for different coding schemes (MPEG, Dolby Digital, DTS) while introducing a central synchronization control unit. This segmentation allows each audio signal to be decoded independently according to its coding scheme while the synchronization unit coordinates their reproduction timing using time stamp information, thereby maintaining both adaptability and synchronization reliability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The synchronization control unit acts as an intermediary between multiple independent audio decoding units and the final reproduction output. It receives time stamp information from each decoding unit, compares the reproduction timing, and generates control signals to adjust the reproduction timing of each audio signal, ensuring they are reproduced in synchronism without requiring changes to the individual decoding units.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If audio signals are decoded by different audio decoding means independently, then various coding schemes can be supported, but the reproduction timing cannot be coordinated

Engineering Contradiction:

Improvesupport for multiple coding schemesVSAvoidreproduction timing coordination

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The synchronization control unit implements a feedback mechanism by continuously monitoring the reproduction timing of each audio signal through time stamp information, comparing the actual reproduction timing with the target synchronization timing, and generating corrective control signals to adjust the reproduction timing of each decoding unit. This closed-loop feedback ensures accurate timing coordination while maintaining support for multiple coding schemes.

Inventive Principle:

Principle #23Feedback

3Productivity

If multiple audio signals are reproduced simultaneously through the same output channels, then channel utilization is efficient, but audio level management becomes complex

Engineering Contradiction:

Improveoutput channel utilization efficiencyVSAvoidaudio level management

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The invention introduces dynamic audio level management through the synchronization control unit, which adjusts the output levels of different audio signals in real-time based on their reproduction timing and channel allocation. This dynamic adjustment allows efficient utilization of output channels for multiple simultaneous audio signals while automatically managing audio levels to prevent distortion and maintain sound quality, reducing the complexity of manual level management.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS7877156B2Audio reproducing apparatus, audio reproducing method, and program

Publication Date: 2011.01.25 PANASONIC HOLDINGS CORP

AI summary

This invention provides an audio reproducing apparatus which reproduces plural digital audio signals and synchronizes them with each other. The audio reproducing apparatus includes a synchronization setting unit 11 which synchronizes the plural audio signals by allocating, on a time axis, plural pieces of audio reproduction time information of the audio signals and in a manner which maintains a difference between reproduction times indicated by adjacent pieces of the audio reproduction time information of each of the audio signals, and an audio synthesis unit 6 which synthesizes the plural audio signals using the plural pieces of the audio reproduction time information allocated on the time axis.