Media Player Digital Audio Sample Rate Adaptation

Solution Overview

Problem

Portable media players typically convert digital audio to analog before transmission to accessories, losing quality and failing to leverage the advantages of digital audio, such as wider dynamic range and noise resistance.

Innovation Solution

The system determines the sample rate capabilities of an accessory and converts digital audio to a supported sample rate for seamless transmission, allowing for efficient digital audio transfer between media players and accessories through an interface protocol.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If digital audio is converted to analog form before transmission to accessories, then compatibility with traditional accessories is improved, but audio quality and dynamic range are reduced

Engineering Contradiction:

Improvecompatibility with traditional accessoriesVSAvoidaudio quality

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The system dynamically adapts the audio transmission format based on the accessory's capabilities. The media player determines whether the accessory supports digital audio and automatically switches between digital and analog transmission modes, allowing optimal audio quality when digital is supported while maintaining broad compatibility when it is not.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the transmission parameter (digital vs. analog audio format) based on the accessory's supported formats. The media player queries the accessory for supported audio formats and adjusts the transmission format accordingly, enabling high-quality digital transmission when the accessory supports it while falling back to analog for traditional accessories.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If digital audio is transmitted directly to accessories, then audio quality and noise resistance are improved, but compatibility with accessories that only support analog audio is reduced

Engineering Contradiction:

Improveaudio qualityVSAvoidcompatibility with accessories

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The system dynamically adapts the audio transmission format based on the accessory's capabilities. The media player determines whether the accessory supports digital audio and automatically switches between digital and analog transmission modes, allowing optimal audio quality when digital is supported while maintaining broad compatibility when it is not.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the transmission parameter (digital vs. analog audio format) based on the accessory's supported formats. The media player queries the accessory for supported audio formats and adjusts the transmission format accordingly, enabling high-quality digital transmission when the accessory supports it while falling back to analog for traditional accessories.

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If sample rate conversion is performed to match accessory capabilities, then compatibility with the accessory is improved, but processing time and complexity increase

Engineering Contradiction:

Improvecompatibility with accessory sample ratesVSAvoidprocessing time

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The system performs preliminary actions by querying the accessory for its supported sample rates before audio transmission begins. This advance information gathering allows the media player to pre-determine the appropriate sample rate conversion needed, avoiding real-time conversion delays during actual audio playback.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The accessory itself provides information about its supported sample rates through the accessory protocol, eliminating the need for the media player to perform complex detection or trial-and-error testing. The system uses the accessory's own self-reported capabilities to determine the appropriate transmission parameters.

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS7826318B2Method and system for allowing a media player to transfer digital audio to an accessory

Publication Date: 2010.11.02 APPLE INC

AI summary

Digital audio can be transferred between a portable media player and an accessory. In one embodiment, an interface protocol is used to determine the sample rate capabilities of an accessory, allowing digital audio data for a track to be transmitted to the accessory at a sample rate supported by the accessory. When the sample rate of an audio track is not supported by the accessory, the media player can convert the sample rate of the track to a rate supported by the accessory and transmit the track after conversion. The media player also can use the interface protocol to inform the accessory if the sampling rate should be changed, e.g., due to tracks having different sample rates. The accessory then can send a request to the media player to change the sample rate. The media player then can transmit the digital audio data using the new sample rate.