Transcoder Reducing Processing Amount via Prediction Mode Reuse
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional transcoding methods, such as those using the H.264/AVC coding standard, face significant processing challenges when converting coded streams with intra prediction to those with both intra and inter prediction, as they require extensive decoding and coding processes, leading to high processing amounts.
Innovation Solution
A transcoder is designed to decode coded streams on a predetermined unit basis, obtaining and utilizing intra prediction modes during decoding to apply either intra or inter prediction during recoding, thereby reducing processing by eliminating the need to determine prediction modes and generating cost values based on decoded information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional transcoding methods decode and recode the coded stream, then the transcoding can be performed reliably, but the processing amount becomes large
Solution Approach 1:
The patent applies preliminary action by obtaining the intra prediction mode during the decoding phase and storing it for later use. This pre-acquired information is then reused in the coding phase, eliminating the need to perform intra prediction mode determination again. This resolves the contradiction by maintaining reliable transcoding through proper prediction mode usage while significantly reducing the processing amount by avoiding redundant calculations.
2Productivity
If motion vector is reused for transcoding, then the processing amount for recoding is reduced, but the technique cannot be applied when intra prediction is used
Solution Approach 1:
The patent achieves universality by creating a solution that works for both inter prediction and intra prediction scenarios. Instead of relying solely on motion vectors (which only apply to inter prediction), the patent reuses prediction mode information that is universally applicable to both intra and inter prediction types. This allows the transcoding technique to be applied across different prediction methods, resolving the limitation of the conventional motion vector-based approach.
3Manufacturing precision
If intra prediction mode determination is performed during coding, then the coding accuracy is maintained, but the processing amount increases
Solution Approach 1:
The patent applies the copying principle by reusing the intra prediction mode information that was determined during decoding and copying it for use in the coding phase. Instead of performing independent intra prediction mode determination during coding (which would maintain accuracy but increase processing), the patent copies the previously determined mode information. This approach maintains coding accuracy by using the correct prediction mode while significantly reducing the processing amount by avoiding redundant mode determination calculations.
Data Source
AI summary
A transcoder reduces the processing amount when a coded stream to which at least intra prediction is applied is transcoded into a coded stream to which intra prediction and inter prediction are applied. The transcoder converts a first coded stream to at least part of which intra prediction is applied, into a second coded stream to which intra prediction and inter prediction are applied. The transcoder includes a decoding unit that decodes the first coded stream to generate decoded image data; a prediction mode obtaining unit that obtains a prediction mode of intra prediction applied in decoding; and a coding unit that codes the decoded image data by applying the intra prediction or inter prediction to generate the second coded stream. A control unit controls causes the coding unit to use the prediction mode obtained by the prediction mode obtaining unit when the coding unit applies intra prediction.