Screencasting Parameter Negotiation for Multi-Device Display Smoothness

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

When multiple source devices project display data onto a destination device, the available transmission bandwidth decreases, leading to reduced transmission speed, frame freezing, and delays due to insufficient computing capability of the destination device.

Innovation Solution

The source and destination devices dynamically negotiate projection parameters such as transmission bit rate, encoding compression rate, and resolution based on the number of source devices to ensure smoothness or definition during projection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If multiple source devices simultaneously send display data to the destination device, then the display content coverage increases, but the transmission bandwidth per device decreases and transmission speed reduces

Engineering Contradiction:
Improvenumber of source devicesVSAvoidtransmission speed
Core Design Contradiction:
Quantity of substanceVSSpeed

Solution Approach 1:

The patent implements dynamic parameter adjustment where the destination device negotiates projection parameters (bit rate, resolution, frame rate) with each source device based on the current number of connected source devices. When more devices connect, the system automatically reduces per-device transmission quality to maintain overall system performance, and vice versa. This dynamic adaptation resolves the contradiction between supporting multiple devices and maintaining transmission speed.

Inventive Principle:
Principle #15Dynamics

2Quantity of substance

If the destination device decodes display data from multiple source devices simultaneously, then the display content diversity increases, but the computing capability becomes insufficient causing frame freezing and delays

Engineering Contradiction:
Improvenumber of source devicesVSAvoiddisplay smoothness
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent changes decoding parameters (bit rate, resolution, frame rate) based on the number of source devices to balance processing load and display quality. When multiple devices are connected, the system reduces the decoding complexity for each device to prevent frame freezing and maintain reliable display operation across all devices.

Inventive Principle:
Principle #35Parameter changes

3Speed

If the transmission bit rate is increased to improve transmission speed, then the transmission efficiency improves, but the available bandwidth for each source device decreases when multiple devices are connected

Engineering Contradiction:
Improvetransmission speedVSAvoidnumber of source devices
Core Design Contradiction:
SpeedVSQuantity of substance

Solution Approach 1:

The system dynamically adjusts the transmission bit rate based on the number of connected source devices. When fewer devices are connected, higher bit rates are used to achieve faster transmission speeds and better quality. When more devices connect, the bit rate is automatically reduced to ensure fair bandwidth distribution and prevent system overload, resolving the contradiction between transmission speed and device quantity.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3972262B1Screencasting display method, and electronic apparatus
Publication Date: 2026.03.25 HUAWEI TECH CO LTD
  • EP3972262B1 patent drawingFigure 1~2(b)
  • EP3972262B1 patent drawingFigure 3
  • EP3972262B1 patent drawingFigure 4

AI summary

Embodiments of this application provide a projection display method and an electronic device, and relate to the field of terminal technologies, to dynamically adjust, based on a quantity of source devices, a parameter of display data projected onto a destination device, so as to improve display smoothness and use experience of a user during projection. The method includes: A source device sends a projection instruction to a destination device, where the projection instruction is used to instruct to project a display interface of the source device onto the destination device for display. The source device receives a first broadcast sent by the destination device, where the first broadcast includes a quantity N of source devices that need to perform projection onto the destination device for display. The source device negotiates a first projection parameter with the destination device based on the quantity N of the source devices, where the first projection parameter includes one or more of a projection resolution, a transmission bit rate, or an encoding compression rate. The source device sends first display data to the destination device based on the first projection parameter.