Audio Frame CRC and Fade Control for Digital Broadcast Pop-Noise
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Solution Overview
Problem
Existing methods for digital broadcasting are unable to accurately determine and prevent pop-noise occurrence due to radio frequency interference and weak electric field environments, leading to errors in digital audio signals and potential hearing damage from acoustic shocks.
Innovation Solution
A pop-noise removing method that performs a cyclic redundancy check (CRC) on audio stream data in units of frames, applying fade-in technology to prevent pop-noise by determining broken frames and maintaining a fade-in or fade-out state based on error detection, thereby minimizing noise during signal output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If mute is turned on/off based on mute threshold level and signal quality level in related art, then mute detection is implemented, but pop-noise occurs due to inaccurate output time determination
Solution Approach 1:
The patent performs CRC error detection on audio frame data before decoding to identify broken frames in advance. When a broken frame is detected, the system applies fade-in/fade-out processing to the audio signal before output, preventing pop-noise from occurring at the output stage. This preliminary error detection and corrective action resolves the contradiction by ensuring reliable pop-noise prevention while maintaining accurate mute level detection.
2Reliability
If CRC error detection is performed on audio frame data, then broken frames are identified, but additional processing steps are required
Solution Approach 1:
The patent introduces an error detection unit as an intermediary component that performs CRC checks on audio frame data between the audio decoder and output stage. This intermediary unit identifies broken frames and triggers fade-in/fade-out processing, providing reliable error detection while keeping the added complexity manageable through a dedicated modular component rather than integrating error handling throughout the entire system.
3Object-affected harmful factors
If fade-in processing is applied to prevent pop-noise, then acoustic shocks are reduced, but audio output time is extended
Solution Approach 1:
The patent applies fade-in and fade-out processing selectively only to audio frames that are detected as broken through CRC error detection. Instead of applying gradual volume changes to all audio output, the system maintains normal audio playback for intact frames and applies time-extending fade processing only where necessary to prevent pop-noise from broken frames. This localized application reduces acoustic shocks while minimizing the overall time loss.
Data Source
AI summary
Provided is a pop-noise removing method. The pop-noise removing method analyzes an acoustic noise, occurring when receiving digital broadcasting under a weak electric field environment, and reduces a pop-noise on the basis of the analyzed result, for transferring digital broadcasting with a minimized pop-noise to consumers. Accordingly, an output of the pop-noise of digital broadcasting can be minimized.