Dual-layer video stream backwards compatibility
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Solution Overview
Problem
Current video broadcasting technologies face challenges in delivering high frame rate progressive video to older receivers while maintaining backwards compatibility, as transmitting 1080p streams requires twice the bandwidth of traditional HD broadcasts and existing methods fail to fully restore high frequencies, leading to loss of sharpness and fine detail in reconstructed progressive signals.
Innovation Solution
A dual-layer stream is created by combining a backwards-compatible interlaced video stream layer with a full-resolution progressive video stream layer, using vertical and horizontal pre-processing to preserve high-frequency content, allowing for better picture quality and efficient bandwidth usage through multiview coding and hierarchical coding methods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a 1080p stream is transmitted to accommodate newer HDTVs, then picture quality and resolution are improved, but bandwidth requirements increase to twice that of traditional HD broadcasts
Solution Approach 1:
The video signal is segmented into two separate streams: a base layer containing the 1080p progressive signal and an enhancement layer containing the 720p or 1080i interlaced signal. This segmentation allows the broadcast to serve both newer 1080p HDTVs and older interlaced receivers simultaneously, with each receiver type utilizing only the appropriate layer, thereby optimizing bandwidth usage while maintaining high picture quality for capable devices.
2Adaptability or versatility
If separate channels are used to transmit both 720p/1080i and 1080p streams for backwards compatibility, then compatibility with older receivers is improved, but bandwidth requirements increase to twice that of traditional HD broadcasts
Solution Approach 1:
The patent merges the base layer and enhancement layer into a single multiplexed transport stream. This combining allows both progressive and interlaced signals to be transmitted together over the same broadcast channel, enabling backwards compatibility with older receivers while delivering high-quality progressive video to newer HDTVs, all within the bandwidth constraints of a single channel rather than requiring twice the bandwidth of separate channels.
3Adaptability or versatility
If existing interlace-to-progressive conversion methods are used, then backwards compatibility is improved, but high-frequency content and sharpness are lost in the reconstructed progressive signal
Solution Approach 1:
The patent applies preliminary action by performing deinterlacing conversion in the enhancement layer before encoding, rather than relying on post-decoding conversion. The interlaced frames are converted to progressive format prior to being encoded into the enhancement layer bitstream, preserving high-frequency content and sharpness. This pre-conversion approach ensures that when newer HDTVs decode the enhancement layer, they receive already-converted progressive video with intact high-frequency details, eliminating the sharpness loss associated with post-decoding conversion methods.
Data Source
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AI summary
Given an input progressive sequence, a video encoder creates a dual-layer stream that combines a backwards-compatible interlaced video stream layer with an enhancement layer to reconstruct full-resolution progressive video. Given two consecutive frames in the input progressive sequence, vertical processing generates a top field-bottom field (TFBF) frame in a base layer (BL) TFBF sequence, and horizontal processing generates a side-by-side (SBS) frame in an enhancement layer (EL) SBS video sequence. The BL TFBF and the EL SBS sequences are compressed together to create a coded, backwards compatible output stream.