Multimedia Playback Rate Curves for Freeze-Free Real-Time Speed Control
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Solution Overview
Problem
Conventional video playback systems experience frame freezing due to high calculation loads when adjusting playback rates through large step-by-step iterations in real-time scenarios, requiring high device performance.
Innovation Solution
A playback control method using a third-order Bézier curve to generate a playback rate curve by calculating playback control coordinates of virtual control points between two adjacent control points, allowing real-time adjustment of multimedia resource playback rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the playback position is updated in real-time during content reproduction, then the playback position accurately reflects the current position, but additional processing operations increase device complexity and power consumption
Solution Approach 1:
The patent pre-calculates and stores playback position information at specific intervals (e.g., every 10 seconds) during content reproduction. When a seek operation is requested, the system retrieves the nearest pre-calculated position rather than calculating from scratch, reducing real-time processing complexity while maintaining acceptable accuracy
Solution Approach 2:
The system creates and stores copy information (metadata about playback positions at different time points) separately from the main content. This allows the playback position to be determined by referencing the copied position data rather than re-processing the entire content stream, reducing computational burden
2Speed
If playback position information is stored for every possible seek point, then seek operations are fast and accurate, but memory requirements increase significantly
Solution Approach 1:
The patent divides the content into multiple segments or time intervals and stores playback position information only at the boundaries of these segments. When a seek operation occurs within a segment, the system uses the boundary position information combined with the segment duration to calculate the appropriate position, reducing memory usage while maintaining seek functionality
Solution Approach 2:
The system stores playback position information at selected intervals rather than continuously, using a sampling approach. This partial action provides sufficient accuracy for most seek operations without the overhead of storing complete position data for every possible seek point, achieving a balance between speed and memory consumption
Data Source
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AI summary
Embodiments of this application provide a playback control method and apparatus. The playback control method includes: receiving a playback rate control instruction submitted by a user for a to-be-processed multimedia resource, and determining playback control coordinates of any two adjacent control points carried in the playback rate control instruction; calculating playback control coordinates of a preset quantity of virtual control points between the any two adjacent control points; and using the any two adjacent control points respectively as a start point and an end point, and drawing a playback rate control curve of a multimedia resource segment between the any two adjacent control points based on the start point, the end point, and the playback control coordinates of the virtual control points.