SDI Data Stream Mapping Device for High-Definition Video
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Solution Overview
Problem
Current SDI standards face challenges in transmitting high-definition video data streams due to data rate limitations and the prohibition of certain synchronization code values, leading to inefficient compression methods that impact image quality.
Innovation Solution
A method for mapping data streams onto SDI channels by grouping words, detecting and recoding most significant bits, and adding supplementary bits to avoid excluded values, thereby reducing overhead and maintaining image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If compression is applied to reduce data rate to fit SDI channel limitations, then data rate compliance is improved, but image quality deteriorates
Solution Approach 1:
The patent extracts and removes the problematic synchronization code values (000h-003h and 3FCh-3FFh) from the data stream before transmission. By taking out these excluded values that cause compliance issues, the system avoids the need for aggressive compression that would compromise image quality, thus resolving the contradiction between data rate compliance and image quality preservation.
Solution Approach 2:
The patent changes the parameter representation of pixel values by mapping excluded values to alternative representations. Instead of transmitting the forbidden code values directly, the system transforms them into acceptable equivalents, allowing the data to fit within SDI channel constraints without requiring high compression ratios that would degrade image quality.
2Reliability
If existing mapping methods are used to prevent transmission of excluded values, then compliance with SDI standards is improved, but overhead increases by 25%
Solution Approach 1:
Instead of applying a comprehensive mapping scheme to all pixel values (which would generate 25% overhead), the patent applies partial action by only detecting and recoding the specific excluded synchronization code values (000h-003h and 3FCh-3FFh). This selective approach maintains standard compliance while minimizing overhead, as only the problematic values are transformed rather than all data.
Solution Approach 2:
The patent segments the 10-bit pixel value range into excluded synchronization code values and valid image data values. By identifying and separately handling only the excluded segments (000h-003h and 3FCh-3FFh), the system avoids applying overhead-generating mapping to the entire data stream, thus reducing overall overhead while maintaining compliance.
3Productivity
If higher compression ratios are applied to compensate for overhead, then throughput is improved, but image quality deteriorates significantly
Solution Approach 1:
The patent converts the potential harm of transmitting excluded synchronization values into a benefit by detecting and recoding them proactively. This transformation eliminates the need for excessive compression, as the recoding mechanism efficiently handles compliance requirements without generating significant overhead, thereby maintaining both high throughput and image quality.
Data Source
AI summary
The invention provides a method for mapping a data stream onto an SDI channel, said data stream comprising a sequence of m-bit words, a range of values from 0 to 2**n−1 and from 2**m−2**n to 2**m−1 being excluded values on said SDI channel. The method comprises the steps of grouping the words to be transmitted, detecting if at least one of the words of the group contains a number of MSB's equal to one, and then recoding these MSBs and adding a constant, in order that no excluded values are obtained. Supplementary bits signal groups that have been recoded.