Bitrate Control Device Using Virtual Buffer for Video Encoding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional bitrate control methods for digital video recorders, such as CBR and VBR, face challenges in maintaining consistent image quality and storage efficiency, particularly in managing bitrate fluctuations and allocating code amounts effectively across frames.
Innovation Solution
A bitrate control device and method that sets target code amounts for each frame, adjusts these based on given information, and utilizes a virtual storage management buffer to save or withdraw code amounts, ensuring a given bitrate is maintained while optimizing storage and image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If VBR is used to allocate larger code amounts to pictures of rapidly varying portions, then image quality is improved, but storage space may increase
Solution Approach 1:
The patent implements a feedback mechanism where the actual code amount of previously encoded pictures is measured and compared against target values. Based on this feedback, the target code amounts for subsequent pictures are dynamically adjusted. This ensures that code amounts are allocated efficiently - giving more bits to complex scenes that need them for quality, while constraining simple scenes to use fewer bits, thereby preventing unnecessary storage space increase
Solution Approach 2:
The patent dynamically adjusts target code amounts for each picture based on its complexity characteristics and previous encoding results. Rather than using fixed CBR allocation, the system adapts the code amount allocation in real-time according to the actual content requirements, allowing optimal balance between image quality and storage efficiency
2Manufacturing precision
If target code amount is increased for pictures with large information amounts, then image quality is maintained, but bitrate fluctuation increases
Solution Approach 1:
The system measures the actual code amount used for each encoded picture and feeds this information back to adjust target code amounts for subsequent pictures. This feedback loop smooths bitrate fluctuations by compensating for deviations from target values in real-time, maintaining both image quality consistency and bitrate stability
Solution Approach 2:
The patent introduces an intermediate control mechanism that acts as a mediator between the variable code amount requirements of different pictures and the need for stable bitrate. The target code amount adjustment mechanism serves as this intermediary, smoothing out extreme variations while ensuring complex pictures receive adequate code amounts for quality maintenance
3Quantity of substance
If code amount is reduced for pictures with small information amounts, then storage efficiency is improved, but image quality may deteriorate
Solution Approach 1:
The patent applies local quality control by setting different target code amounts for different pictures based on their specific characteristics. Pictures with small information amounts are allocated reduced code amounts to improve storage efficiency, while pictures with large information amounts receive increased code amounts to maintain quality. This localized adaptation ensures quality is maintained only where necessary
4Quantity of substance
If CBR is used to maintain constant code amount per time segment, then storage efficiency is improved, but image quality deteriorates in complex scenes
Solution Approach 1:
The patent transitions from static CBR to dynamic VBR with controlled fluctuations. The system dynamically adjusts code amount allocation based on scene complexity and previous encoding results, allowing efficient storage utilization while preventing quality deterioration in complex scenes through adaptive code amount increases
Data Source
AI summary
A bitrate control device controls bitrate of video data and includes: a setting module that sets, for each frame in the video data, a target code amount to be used in encoding the frame by an encoding module for maintaining a given bitrate; an adjusting module that adjusts the target code amount set by the setting module based on given information; and a managing module that is configured to perform: saving a code amount corresponding to an amount reduced in the target code amount by the adjusting module in a virtual storage management buffer having a given upper limit, when the adjusting module adjusts to reduce the target code amount; and withdrawing a code amount corresponding to an amount increased in the target code amount by the adjusting module from the virtual storage management buffer, when the adjusting module adjusts to increase the target code amount.