Video Rendering Delay Calculation for Packet Loss Compensation

Solution Overview

Problem

Existing video transmission technologies face challenges in maintaining high video quality over limited bandwidth channels, particularly in real-time encoding and transmission, where packet loss and network jitter cause delays and gaps in the video stream, leading to freezing or errors during rendering.

Innovation Solution

A method and apparatus for rendering video streams that calculate a render time for each frame based on its estimated arrival time, retransmission rendering delay, and jitter delay, using a processor to determine the optimal time for rendering frames and minimize disruptions, even in the presence of packet loss and network variations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If real-time encoding and transmission is used to meet user expectations for high resolution video, then video quality is improved, but network bandwidth consumption increases and packet loss occurs

Engineering Contradiction:

Improvevideo qualityVSAvoidbandwidth consumption

Core Design Contradiction:

Manufacturing precisionVSLoss of energy

Solution Approach 1:

The system performs preliminary actions by calculating estimated arrival times and retransmission delays before rendering frames. The receiver computes render times in advance using formulas that incorporate round-trip delay estimates, allowing the system to proactively schedule frame rendering to compensate for anticipated network variations and packet losses.

Inventive Principle:

Principle #10Preliminary action

2Speed

If video frames are rendered as they are received to maintain real-time playback, then playback latency is reduced, but video freezes and errors occur due to packet loss and network jitter

Engineering Contradiction:

Improveplayback latencyVSAvoidvideo playback continuity

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The system performs preliminary actions by calculating estimated arrival times and retransmission delays before rendering frames. The receiver computes render times in advance using formulas that incorporate round-trip delay estimates, allowing the system to proactively schedule frame rendering to compensate for anticipated network variations and packet losses.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system applies beforehand cushioning by adding retransmission rendering delay to the estimated arrival time to compute the render time. This delay acts as a cushion or buffer that compensates for potential packet losses and network jitter, ensuring that frame rendering is scheduled with sufficient margin to maintain playback continuity even when frames are lost or delayed.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Reliability

If retransmission rendering delay is calculated using round-trip delay to compensate for packet loss, then video playback reliability is improved, but rendering delay increases

Engineering Contradiction:

Improvevideo playback continuityVSAvoidrendering delay

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The system performs preliminary actions by calculating estimated arrival times and retransmission delays before rendering frames. The receiver computes render times in advance using formulas that incorporate round-trip delay estimates, allowing the system to proactively schedule frame rendering to compensate for anticipated network variations and packet losses.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system applies beforehand cushioning by adding retransmission rendering delay to the estimated arrival time to compute the render time. This delay acts as a cushion or buffer that compensates for potential packet losses and network jitter, ensuring that frame rendering is scheduled with sufficient margin to maintain playback continuity even when frames are lost or delayed.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentUS8750293B2Apparatus and method for rendering video with retransmission delay

Publication Date: 2014.06.10 GOOGLE LLC

AI summary

A system, apparatus, and method for rendering a video stream, the video stream having a plurality of frames. One method includes receiving the plurality of frames via a network, each frame having an estimated arrival time, determining a retransmission rendering delay, based on a round-trip delay and a round-trip delay constant, for a current frame of the plurality of frames using a processor, determining a render time for the current frame using a sum of the current frame's estimated arrival time and the retransmission rendering delay, and rendering the current frame at the render time.