Bitstream Alignment Using Auxiliary Information for Hybrid Video Standards
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Solution Overview
Problem
Existing methods for bitstream alignment and synchronization in hybrid coding of different video standards, such as H.264/AVC and H.265/HEVC, require modifications to coding and decoding devices, leading to complex implementation, poor universality, and high costs.
Innovation Solution
The method involves setting alignment auxiliary information in bitstreams of different standards, allowing the transmitting terminal to determine and store or transmit this information, which the receiving terminal uses for synchronization without needing additional codec modifications, by utilizing existing information or adding new content in fields like supplemental enhancement information, video usability information, or slice headers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If bitstreams of different video standards are packed as a whole with internal means, then synchronization between layers is achieved, but standard decoders cannot decode the bitstream and require unpacking and modification
Solution Approach 1:
The patent introduces an intermediary mechanism by adding identification information (flags and syntax elements) to the bitstream that enables standard decoders to recognize and properly handle hybrid coded pictures. This intermediary layer of information allows the decoder to distinguish between base layer and enhancement layer data without requiring complex unpacking logic, thus maintaining decoder compatibility while achieving reliable synchronization
Solution Approach 2:
The patent segments the bitstream processing by introducing separate identification mechanisms for base layer and enhancement layer pictures. By adding specific syntax elements (e.g., bl_pic_header_extension, el_pic_header_extension) and flags, the system divides the decoding process into recognizable segments that standard decoders can handle independently, eliminating the need for unpacking while maintaining synchronization
2Ease of operation
If prefix bytes are added to identify different bitstreams, then decoders can identify their own bitstreams, but additional information and processing requirements increase complexity
Solution Approach 1:
The patent extracts the identification function from complex prefix byte mechanisms and relocates it to existing bitstream structures. By utilizing syntax elements that are already present in the video coding framework (such as picture parameter sets and slice headers), the system achieves bitstream identification without adding external prefix bytes, thereby reducing decoder complexity while maintaining ease of operation
Solution Approach 2:
The patent makes existing bitstream syntax elements serve multiple functions: they both convey video coding information and provide identification for hybrid coded pictures. For example, the pic_order_cnt_lsb and POC_offset_intra_view_idx syntax elements are used both for their original timing purposes and as identification markers for enhancement layer pictures, eliminating the need for separate identification mechanisms and reducing overall system complexity
3Adaptability or versatility
If decoder modifications are made to support hybrid coding, then hybrid coding function is achieved, but implementation cost and complexity increase
Solution Approach 1:
The patent enables the bitstream to self-identify its structure through embedded syntax elements and flags, allowing standard decoders to automatically recognize and process hybrid coded pictures without requiring modification. The bitstream carries its own identification information (e.g., bl_pic_header_extension with is_bl_pic_header_extension_flag) that guides the decoder's processing, making the system adaptable to hybrid coding while maintaining simple, unmodified decoders
Solution Approach 2:
The patent changes the parameters of existing bitstream structures by adding extension syntax elements that modify the behavior of standard decoders. By introducing parameters such as bl_pic_header_extension, el_pic_header_extension, and related flags into the existing video coding framework, the system achieves hybrid coding capability through parameter extensions rather than structural modifications, keeping implementation costs low while increasing versatility
Data Source
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AI summary
Disclosed are a bitstream alignment and synchronous processing method, transmitting terminal, receiving terminal and communication system. The method comprises: configuring, when multiple bitstreams are required to be aligned, by a transmitting terminal, alignment auxiliary information in the multiple bitstreams so as to store the same or transmit the same to a receiving terminal; and acquiring, by the receiving terminal, the multiple bitstreams, and synchronizing each of the bitstreams of a different standard according to the alignment auxiliary information carried in each of the bitstreams. Therefore, the present invention directly sets the alignment auxiliary information in each of the bitstreams, is easy to realize and not required to make any additional change to a codec, and has good compatibility and a low realization cost.