WFD Source Auxiliary Stream Resolution Adaptation
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Solution Overview
Problem
Current wireless display transmission technologies, such as WiFi Miracast, face limitations in adapting auxiliary data like subtitles and user interface elements to the native resolution of receiving devices, leading to potential degradation in picture quality and user experience due to rescaling issues.
Innovation Solution
The method involves transmitting auxiliary data with a resolution optimized for the receiving device by determining the native or maximum supported resolution during the WFD service discovery and RTSP capability negotiation, allowing the receiving device to output subtitles and user interface elements without rescaling, while only rescaling video data as necessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If auxiliary data is transmitted with the source device resolution, then the data can be displayed on any device, but the picture quality degrades when displayed on devices with different native resolutions due to rescaling
Solution Approach 1:
The patent applies local quality by transmitting auxiliary data at different resolutions depending on the receiving device's capabilities. The source device determines the native resolution of the receiving device and transmits auxiliary data optimized for that specific resolution, rather than using a single resolution for all devices. This resolves the contradiction by making the quality and resolution properties local to each receiving device rather than uniform across all devices.
Solution Approach 2:
The patent changes the resolution parameter of auxiliary data based on the receiving device's native resolution. During the capability negotiation phase, the source device obtains resolution information from the receiving device and adjusts the auxiliary data transmission parameters accordingly. This allows auxiliary data to be transmitted at optimal quality for each device without requiring rescaling, thus maintaining picture quality while ensuring compatibility.
2Manufacturing precision
If auxiliary data is rescaled to match the receiving device resolution, then the picture quality is maintained, but additional processing complexity and time are required
Solution Approach 1:
The patent performs preliminary action by determining the receiving device's native resolution during the capability negotiation phase, before auxiliary data transmission begins. The source device obtains resolution information through WFD service discovery and RTSP capability negotiation, then configures the auxiliary data transmission parameters in advance. This eliminates the need for real-time rescaling processing during playback, reducing processing complexity while maintaining picture quality.
3Manufacturing precision
If auxiliary data is transmitted at high resolution, then the clarity is improved, but the bandwidth consumption increases
Solution Approach 1:
The patent dynamically changes the resolution parameter of auxiliary data based on the receiving device's capabilities. By obtaining the native resolution information during capability negotiation and adjusting the auxiliary data transmission resolution accordingly, the system transmits auxiliary data at the highest possible quality that the receiving device can display without wasting bandwidth on excessive resolution. This resolves the contradiction by optimizing the resolution parameter to match actual display capabilities.
Data Source
AI summary
A method and apparatus for outputting a supplementary content from a WFD is disclosed. The method for outputting a supplementary content from a WFD may comprise the steps of: after a WFD source is connected to a WFD, transmitting, by the WFD source, an RTSP parameter request message on the basis of an RTSP to a WFD sink in order to perform a capability negotiation procedure with the WFD sink; transmitting, by the WFD source, an RTSP parameter response message to the WFD sink in response to the RTSP parameter request message; and after performing the capability negotiation procedure, transmitting, by the WFD source, a transmission stream, obtained by overlapping and multiplexing a video stream including video data having a first resolution and a supplementary stream including supplementary data having a second resolution, to the WFD sink, wherein a WFD discovery response frame includes second resolution-related information for determining the second resolution, and an RTSP parameter response frame includes the second resolution-related information.