HDMI Audio Volume Control via CEC for Precise Level Setting
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Solution Overview
Problem
The HDMI standard only allows for discrete volume control, such as volume up or volume down, and does not include an instruction for setting a system volume level to a specific level, like a percentage of the maximum volume, limiting the precision of volume control in HDMI audio systems.
Innovation Solution
Methods and systems for controlling an HDMI audio system involve determining the current volume level, calculating the necessary change to reach a requested volume level, and sending volume control messages over the Consumer Electronic Control (CEC) bus to incrementally adjust the volume until it reaches the desired level, using a second screen device to input the requested volume level.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If discrete volume control instructions (volume up/down) are used in HDMI audio system, then the system is compatible with existing HDMI standard, but the volume control precision is limited and cannot set to specific levels
Solution Approach 1:
The patent segments the volume control process into multiple discrete steps, where each CEC message adjusts the volume by a specific increment. By breaking down the continuous volume adjustment into discrete segments, the system achieves precise volume control while maintaining compatibility with the HDMI standard's discrete control mechanism.
Solution Approach 2:
The patent employs periodic action by sending multiple volume control messages in sequence, with each message adjusting the volume by a fixed increment. This periodic adjustment approach allows the system to reach any desired volume level through repeated application of the same control mechanism, achieving precision without requiring new instruction types.
2Measurement precision
If incremental volume adjustment through repeated messages is implemented, then precise volume control is achieved, but the control process time increases
Solution Approach 1:
The patent calculates the required volume adjustment and determines the number of messages needed in advance, before initiating the volume control process. This preliminary calculation optimizes the control sequence, ensuring that the minimum number of messages is sent to reach the target volume level, thereby reducing the overall adjustment time while maintaining precision.
Solution Approach 2:
The patent implements dynamic adjustment by adapting the volume control process based on the difference between current and target volume levels. The system dynamically determines the number of incremental steps required and adjusts the control sequence accordingly, optimizing the balance between precision and speed for each specific control scenario.
Data Source
AI summary
Mechanisms for controlling an audio level of an HDMI audio system are provided, the mechanisms comprising: causing audio data to be presented by an HDMI audio system at a current system volume level; receiving a requested volume level from a second screen device; and controlling a system volume level by: (a) determining the current system volume level; (b) determining a change in volume based on a difference between the requested volume level and the current system volume level; (c) determining a direction in which to cause the system volume level to change; (d) sending a volume control message to the system using a consumer electronic control bus connected to the system indicating whether to increase or decrease the system volume level based on the determined direction of system volume change; and (e) repeating (a)-(d) until the current system volume level reaches a predetermined value.