Transcoder Parameter Adaptation for Video Decoding Compatibility
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional transcoders fail to decode and reproduce moving image signals when parameters used by the transmission and receiving side devices differ, leading to incorrect decoding of intra-frame coded frames, which in turn affects the decoding of subsequent inter-frame prediction coded frames.
Innovation Solution
A moving image compression-coding system conversion device that includes a decoding unit, a coding control unit to set parameters based on receiving decoding information, and a coding unit for compression-coding, enabling intra-frame coding of the first frame and inter-frame prediction coding of subsequent frames, ensuring compatibility with different compression-coding systems and parameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional transcoder converts coded bit streams without obtaining receiving side decoding parameters, then the transcoder can operate independently, but the coded bit stream cannot be decoded and reproduced correctly by the receiving side decoding device due to parameter differences
Solution Approach 1:
The transcoder obtains receiving side decoding parameters (DCI) from the receiving side decoding device and uses this feedback information to adjust its encoding parameters. This ensures the converted bit stream is compatible with the receiving device's decoding capabilities, resolving the parameter mismatch problem while maintaining system independence.
Solution Approach 2:
The transcoder dynamically adapts its encoding parameters based on the received DCI information from the receiving side. By making the encoding process adaptive rather than static, the transcoder can correctly encode first frames with intra-frame coding and subsequent frames with inter-frame prediction coding according to the receiving device's capabilities.
2Reliability
If intra-frame coding is performed on the first frame by the transcoder, then the receiving side can decode subsequent inter-frame prediction coded frames, but if the transcoder uses different parameters than the receiving side, the first frame cannot be decoded correctly
Solution Approach 1:
The transcoder changes its encoding parameters to match the receiving side's decoding parameters by obtaining DCI information. This parameter alignment ensures that the first frame encoded with intra-frame coding can be correctly decoded by the receiving device, while maintaining compatibility across different compression-coding systems like H.261, H.263, and MPEG-4.
Solution Approach 2:
The transcoder performs preliminary action by obtaining the receiving side's DCI parameters before encoding the first frame. This advance preparation ensures that the encoding parameters are already configured correctly for the receiving device's capabilities, preventing decoding errors in the first frame and enabling subsequent inter-frame prediction decoding.
3Productivity
If the transcoder uses fixed encoding parameters, then the encoding process is simple and fast, but the converted bit stream cannot be decoded when receiving side parameters differ from transmission side parameters
Solution Approach 1:
The transcoder implements a dynamic parameter adjustment mechanism where encoding parameters are adapted based on received DCI information. This dynamic approach maintains high encoding speed by using pre-standardized parameter sets while ensuring compatibility with the receiving side's decoding capabilities, resolving the conflict between speed and adaptability.
Data Source
AI summary
To enable to output, from a transcoder, a coded bit stream which can be decoded and reproduced by a receiving side moving image decoding device, irrespective of whether a coding tool or the like of the moving image compression-coding system being used in the receiving side moving image decoding device. A coding control unit outputs coding tool control information based on receiving decoding information received from the receiving side moving image decoding device. A DCT, a quantizer and a variable length encoder change operations based on the coding tool control information. The coding control unit outputs coding start information based on the receiving decoding information. A transcode start judging unit outputs a moving image signal based on the coding start information so as to operate to start transcoding.