Dynamic Bitrate Adjustment via Buffer Length Thresholds

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Solution Overview

Problem

Existing multiple bitrate streaming algorithms face challenges in accurately adjusting bitrate based on available bandwidth, leading to potential interruptions and quality issues due to inaccuracies in bandwidth estimation.

Innovation Solution

A method is introduced that determines multiple thresholds based on buffer length to adjust the aggressiveness of the multiple bitrate algorithm, increasing or decreasing the requested bitrate accordingly, thereby improving bandwidth estimation accuracy and reducing playback interruptions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the multiple bitrate algorithm increases aggressiveness to maximize visual quality by selecting higher bitrate segments, then the visual quality improves, but the risk of playback interruptions increases due to insufficient buffer availability

Engineering Contradiction:

Improvevisual qualityVSAvoidplayback continuity

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The patent applies dynamics by making the aggressiveness factor of the multiple bitrate algorithm variable rather than fixed. The aggressiveness is dynamically adjusted based on the current buffer length, allowing the system to adapt between conservative and aggressive bitrate selection strategies in real-time, thus balancing visual quality maximization with playback continuity assurance

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of aggressiveness in the bitrate selection algorithm based on buffer length conditions. By modifying this parameter according to buffer state, the system can shift between different operational modes (conservative vs. aggressive) to optimize the trade-off between quality and reliability under different buffering conditions

Inventive Principle:

Principle #35Parameter changes

2Reliability

If the multiple bitrate algorithm uses conservative aggressiveness to ensure uninterrupted playback by selecting lower bitrate segments, then playback continuity is maintained, but visual quality deteriorates due to lower bitrate selection

Engineering Contradiction:

Improveplayback continuityVSAvoidvisual quality

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The system dynamically adjusts the aggressiveness parameter based on buffer length, transitioning from conservative to aggressive behavior as buffer availability increases. This dynamic adaptation allows the system to maintain reliability when buffers are low while maximizing quality when buffers are sufficient

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The aggressiveness parameter is changed based on buffer length thresholds, allowing the algorithm to switch between conservative and aggressive bitrate selection strategies. This parameter change enables the system to optimize for reliability when needed and for quality when conditions permit

Inventive Principle:

Principle #35Parameter changes

3Manufacturing precision

If the multiple bitrate algorithm aggressively increases requested bitrate based on available bandwidth, then visual quality improves, but bandwidth estimation inaccuracies cause buffer overflows or underflows

Engineering Contradiction:

Improvevisual qualityVSAvoidbandwidth estimation accuracy

Core Design Contradiction:

Manufacturing precisionVSMeasurement precision

Solution Approach 1:

The patent applies beforehand cushioning by using buffer length as a cushioning factor to moderate the impact of bandwidth estimation inaccuracies. The buffer acts as a cushion that absorbs the effects of aggressive bitrate increases when bandwidth estimates are inaccurate, preventing buffer overflows and underflows while still allowing quality improvements when estimates are reliable

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The system implements feedback by continuously monitoring buffer length and using this information to adjust the aggressiveness of bitrate requests. This feedback loop allows the system to learn from past bandwidth estimation accuracy and adjust future requests accordingly, reducing the impact of inaccuracies while maintaining quality optimization

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS9674100B2Dynamic adjustment to multiple bitrate algorithm based on buffer length

Publication Date: 2017.06.06 HULU LLC

AI summary

In one embodiment, a method determines thresholds for a multiple bitrate algorithm that adjusts which bitrates for a media program are requested. A first threshold is associated with a first buffer length and a first direction of adjustment and a second threshold is associated with a second buffer length greater than the first buffer length and a second direction of adjustment. The method then determines which threshold applies to a buffer length of a buffer buffering the media program. An adjustment to the multiple bitrate algorithm in the first direction or the second direction based on the threshold that applies where the adjustment in the first direction increases an aggressiveness used by the multiple bitrate algorithm to increase the bitrate requested and the adjustment in the second direction decreases the aggressiveness used by the multiple bitrate algorithm to increase the bitrate requested.