Bit Rate Control Method for Video Encoding Storage Allocation

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Solution Overview

Problem

Existing bit rate control methods in video encoding struggle to allocate storage space efficiently, leading to wasted resources in VBR mode and unstable image quality in CBR mode, as they fail to accurately manage bit rate fluctuations and image complexity over time.

Innovation Solution

A bit rate control method that combines long and short period control, using a bit rate controller to adjust coding parameters based on real-time complexity information and storage constraints, ensuring accurate storage space allocation and stable image quality by managing the error between actual and set average bit rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If VBR mode is used to maintain stable image quality, then image quality is preserved, but storage space is wasted due to overestimation of required capacity

Engineering Contradiction:
Improveimage quality stabilityVSAvoidstorage resource waste
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent implements dynamic bit rate control by dividing encoding into long periods (for storage space estimation) and short periods (for image quality control). The long period dynamically adjusts the average bit rate based on actual storage capacity, while the short period maintains quality by allowing bit rate fluctuations within each GOP group. This dynamic multi-scale control resolves the contradiction between stable quality and efficient storage utilization.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent segments the bit rate control process into two distinct time scales: long period control (for storage space management) and short period control (for image quality maintenance). By separating these functions into different temporal domains, the system can optimize for both storage efficiency and quality stability without compromise.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If CBR mode is used to accurately estimate storage space, then storage capacity calculation is precise, but image quality degrades in complex scenarios due to bit rate limitations

Engineering Contradiction:
Improvestorage space estimation accuracyVSAvoidimage quality stability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent makes the bit rate control dynamic by allowing short-period fluctuations around the long-period average. During complex encoding scenarios, the short-period control can temporarily exceed the average bit rate to maintain quality, while the long-period control ensures overall storage constraints are met. This resolves the contradiction between precise storage estimation and quality maintenance.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent performs preliminary bit rate allocation at the long-period level to establish storage-compliant average rates, then uses short-period control to adjust actual bit rates based on scene complexity. This preliminary planning followed by adaptive adjustment allows both accurate storage estimation and quality preservation.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If fixed target bit rate is used in CBR mode, then storage space can be accurately allocated, but bit rate cannot be adjusted for complex scenarios leading to quality loss

Engineering Contradiction:
Improvestorage space utilization efficiencyVSAvoidbit rate adaptability to scene complexity
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent transforms the fixed bit rate of CBR into a dynamic control system with two layers: long-period average bit rate (for storage allocation) and short-period instantaneous bit rate (for quality adaptation). This dynamic structure allows the system to adapt to scene complexity while maintaining accurate storage space utilization.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the bit rate parameter from a fixed value to a time-varying parameter with different characteristics at different time scales. The long-period average provides stable storage planning, while short-period variations provide adaptability to content complexity, resolving the contradiction between fixed allocation and flexible adaptation.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3562155B1Bit rate control method and device
Publication Date: 2024.03.20 HANGZHOU HIKVISION DIGITAL TECHNOLOGY CO LTD
  • EP3562155B1 patent drawingFigure 1
  • EP3562155B1 patent drawingFigure 2~3
  • EP3562155B1 patent drawingFigure 4

AI summary

A bit rate control method and device, wherein the bit rate control method comprises: obtaining a bit rate control mode and coding control parameters of a current short period in a long period, determining a frame-level coding parameter of the current short period according to the bit rate control mode and coding control parameters of the current short period in the long period, and transmitting the frame-level coding parameter to an encoder; obtaining second bit stream information sent by the encoder; performing statistical analysis according to the second bit stream information to obtain statistical information including complexity information of the current video frame, the number of the encoded bits in the current short period, and coding quality information of the current short period; when the long period has not ended and if the current short period has ended, obtaining a period length of the current short period, the preset bit rate control parameters and the statistical information, and determining an average bit rate of a next, adjacent short period of the current short period in the long period according to the period length of the current short period, the preset bit rate control parameters and the statistical information, so as to encode a video frame of the next, adjacent short period by calculating a frame-level coding parameter of the next, adjacent short period. By the present solution, the storage space is allocated reasonably under the condition that the image satisfies a certain quality.