Subtitle Encoding Unit Color Gamut Conversion

Solution Overview

Problem

In digital video broadcasting, the superimposition of video data and subtitle graphics data often requires color gamut and dynamic range adjustments, leading to increased processing loads on the receiving side due to differences in color gamut and dynamic range between video and subtitle data.

Innovation Solution

A transmission device generates a container with a video stream and a subtitle stream that includes a bitmap conversion table with color gamut and brightness conversion information, allowing for easy conversion of subtitle graphics data to match the characteristics of the video data on the receiving side, reducing processing load.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If subtitle graphics data is transmitted without color gamut and brightness conversion information, then the transmission process is simple, but the receiving side requires complex processing to match color gamut and dynamic range between video and subtitle data

Engineering Contradiction:

Improvetransmission process complexityVSAvoidreceiving side processing load

Core Design Contradiction:

Device complexityVSEase of operation

Solution Approach 1:

The transmission device performs color gamut and brightness conversion in advance during the transmission process. The subtitle graphics data is converted to match the color gamut and dynamic range of the video data before transmission, so that the receiving side only needs simple superimposition processing without complex color matching algorithms.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

A conversion table is introduced as an intermediary component that stores the mapping relationships between different color spaces and brightness ranges. This conversion table enables efficient color gamut and brightness matching between subtitle data and video data through lookup operations, significantly reducing the processing load on the receiving side.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of operation

If color gamut and brightness conversion is performed on subtitle graphics data before transmission, then the receiving side processing load is reduced, but the transmission device processing load increases

Engineering Contradiction:

Improvereceiving side processing loadVSAvoidtransmission device processing load

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The transmission device performs color gamut and brightness conversion in advance during the transmission process. The subtitle graphics data is converted to match the color gamut and dynamic range of the video data before transmission, so that the receiving side only needs simple superimposition processing without complex color matching algorithms.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The transmission device changes the color space parameters and brightness range parameters of the subtitle graphics data to match the video data characteristics. By transforming the data parameters before transmission, the system achieves compatible color gamut and dynamic range without requiring complex processing on the receiving side.

Inventive Principle:

Principle #35Parameter changes

3Manufacturing precision

If subtitle graphics data is converted to match video data color gamut and dynamic range, then video image quality is maintained at high quality, but data conversion processing is required

Engineering Contradiction:

Improvevideo image qualityVSAvoiddata conversion processing

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The transmission device performs color gamut and brightness conversion in advance during the transmission process. The subtitle graphics data is converted to match the color gamut and dynamic range of the video data before transmission, so that the receiving side only needs simple superimposition processing without complex color matching algorithms.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Instead of performing complex real-time conversion on the receiving side, the system creates a pre-converted copy of the subtitle graphics data with color gamut and brightness adjusted to match the video data characteristics. This pre-processed copy is transmitted along with the original data, enabling quick and accurate superimposition while maintaining high video image quality.

Inventive Principle:

Principle #26Copying

Data Source

PatentEP3389278B1Transmitting device, transmitting method, receiving device and receiving method

Publication Date: 2022.10.12 SATURN LICENSING LLC

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AI summary

To reduce a processing load on a receiving side upon superimposition of subtitle graphics data on video data. A video stream with the video data is generated. A subtitle stream with bitmap data obtained by conversion of the subtitle graphics data is generated. A container containing the video stream and the subtitle stream is transmitted. The subtitle stream contains a first segment having a bitmap conversion table with color gamut and/or brightness conversion information. On the receiving side, the bitmap data is merely converted into the subtitle graphics data by means of the bitmap conversion table so that the subtitle graphics data with characteristics conformable to characteristics of superimposition target video data can be easily obtained.