Macroblock Bit Allocation for H.264 Recoding Limits
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing technologies for recoding H.264 bit streams to H.264 or MPEG-2 bit streams face challenges in suppressing image quality deterioration while transmitting encoded data, as the encoded data per macroblock exceeds the 256-bit limit prescribed by SMPTE 319-2000, leading to potential visible patterns and compatibility issues with MPEG-2 recoding devices.
Innovation Solution
An encoded data selection method that determines the prediction mode and preferentially distributes bits to specific types of encoded data within macroblocks, reducing the number of bits allocated to non-selected data types, and strategically selects motion vectors to limit the total bits per macroblock to 256 or less, ensuring efficient data transmission without significant image quality degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If encoded data per macroblock is transmitted without limitation, then image quality is maintained, but the data exceeds the 256-bit limit prescribed by SMPTE 319-2000, causing compatibility issues and visible patterns
Solution Approach 1:
The patent extracts only the necessary encoded data from macroblocks by determining prediction modes and selectively transmitting motion vectors. Instead of transmitting all encoded data, it identifies and extracts only the critical components needed to maintain image quality while staying within the 256-bit limit.
Solution Approach 2:
The patent applies different transmission strategies to different regions and types of macroblocks based on their prediction modes. Intra-mode macroblocks transmit fewer bits while inter-mode macroblocks with motion vectors transmit selectively, optimizing the distribution of bit allocation across different local regions.
2Adaptability or versatility
If encoded data is reduced to fit within 256 bits per macroblock, then compatibility with MPEG-2 recoding devices is improved, but information loss may occur
Solution Approach 1:
The patent performs preliminary determination of prediction modes before data transmission. By classifying macroblocks into intra-mode or inter-mode in advance and pre-determining which motion vectors are necessary, it prepares the optimal data subset before transmission, ensuring both compatibility and minimal information loss.
Solution Approach 2:
The patent changes the parameter of bit allocation dynamically based on prediction mode. Instead of using a fixed bit allocation, it adjusts the number of bits transmitted for each macroblock type, allocating more bits to inter-mode macroblocks that require motion vectors and fewer bits to intra-mode macroblocks.
3Manufacturing precision
If all motion vectors are transmitted, then image quality is preserved, but the bit count exceeds the 256-bit limitation
Solution Approach 1:
The patent applies partial action by transmitting only the necessary motion vectors rather than all motion vectors. It determines which motion vectors are critical for maintaining image quality and transmits only those, avoiding the excessive transmission of redundant data.
Solution Approach 2:
The patent changes the parameter of motion vector transmission by selectively enabling or disabling motion vector transmission based on prediction mode. This dynamic parameter adjustment optimizes the balance between image quality preservation and transmission efficiency.
Data Source
AI summary
In macroblocks to which a prediction mode determination step, which determines whether or not a prediction mode applied to the macroblocks is a predetermined prediction mode, and an encoded data selection step, which selects a predetermined type of encoded data corresponding to the pixels at predetermined positions in the macroblocks to which the predetermined prediction mode is applied, are applied, there is provided a bit distribution step for more preferentially distributing bits to a predetermined type of encoded data selected at the encoded data selection step than a predetermined type of encoded data that is not selected at the encoded data selection step in the macroblocks to which the predetermined prediction mode is applied. With these steps, it is possible to provide an encoded data selection method which can limit the encoded data per one macroblock transmitted from a decoding device to a recoding device to less than a predetermined value while suppressing the lack ratio of the amount of information of the encoded data as much as possible.