Bit Stream Extraction for Smooth Video Playback

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Solution Overview

Problem

Existing moving image coding technologies face challenges in implementing smooth special reproduction such as fast play and fast reverse play without modifying the decoding apparatus, particularly with H.264 standards, which complicates the decoding apparatus configuration and leads to different decoding results across manufacturers.

Innovation Solution

A method and apparatus that extract and convert bit streams of pictures decodable by themselves, including those with partially decodable image data, into fully decodable streams, allowing for smooth special reproduction without additional functions in the decoding apparatus, by using an extraction unit, conversion unit, and storing unit to adjust coding parameters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If H.264 inter-frame prediction coding is used to improve compression efficiency, then compression rate is improved, but special reproduction becomes difficult because P and B pictures require reference frames for decoding

Engineering Contradiction:

Improvecompression efficiencyVSAvoidspecial reproduction capability

Core Design Contradiction:

Loss of substanceVSEase of operation

Solution Approach 1:

The video stream is segmented into I pictures (intra-coded) and P/B pictures (inter-coded). For special reproduction, only I pictures are extracted and processed, separating the fully decodable segments from those requiring reference frames. This allows smooth fast-forward and fast-reverse playback using only self-contained I picture segments.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

I pictures are prepared in advance as standalone decodable units within the encoded video stream. These pre-prepared self-contained segments enable immediate special reproduction without needing to reconstruct reference frames from inter-picture dependencies during playback.

Inventive Principle:

Principle #10Preliminary action

2Ease of operation

If only I pictures are extracted for fast play to enable smooth special reproduction, then special reproduction quality is improved, but the number of available frames is reduced

Engineering Contradiction:

Improvespecial reproduction smoothnessVSAvoidframe availability

Core Design Contradiction:

Ease of operationVSProductivity

Solution Approach 1:

The encoding parameters are configured to increase the frequency of I pictures in the video stream. By changing the I-picture insertion interval parameter, more self-contained decodable frames are available for extraction, improving both the smoothness of special reproduction and the number of frames available for fast-play playback.

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If decoding apparatus is modified to support H.264 special reproduction of P and B pictures, then decoding capability is improved, but device complexity increases

Engineering Contradiction:

Improvedecoding capabilityVSAvoidapparatus configuration

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The solution extracts only I pictures from the H.264 bitstream for special reproduction, taking out the fully decodable segments while leaving the complex inter-picture dependency structure of P and B pictures behind. This extraction approach enables special reproduction using standard decoders without requiring modifications to handle reference frame management for inter-coded pictures.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

A simplified bitstream is created by copying and reassembling only the I picture segments from the original H.264 stream. This copied subset maintains full decodability with standard apparatus while eliminating the complexity of inter-picture references, allowing special reproduction without modifying the decoding apparatus.

Inventive Principle:

Principle #26Copying

4Adaptability or versatility

If different manufacturers implement H.264 decoding differently to support special reproduction, then special reproduction functionality is improved, but compatibility decreases

Engineering Contradiction:

Improvespecial reproduction functionalityVSAvoiddecoding consistency

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The solution creates a homogeneous subset of the video stream consisting only of I pictures, which have uniform self-contained decodability characteristics. This homogeneous extraction ensures that any standard H.264 compliant decoder will interpret and play back the special reproduction stream identically, guaranteeing cross-manufacturer compatibility and consistent decoding results.

Inventive Principle:

Principle #33Homogeneity

Data Source

PatentUS8731065B2Dynamic image stream processing method and device, and dynamic image reproduction device and dynamic image distribution device using the same

Publication Date: 2014.05.20 NEC CORP

AI summary

There are included: an extraction unit that extracts a first bit stream of a picture that is decodable by itself and a second bit stream of a picture whose image data part is decodable by itself but a part other than the image data part is not decodable by itself from a coded bit stream of a moving image; and a conversion unit that converts the second bit stream extracted by the extraction unit into a third bit stream of a picture that is decodable by itself, the first bit stream of the picture extracted by the extraction unit and the third bit stream being arranged and output in order of extraction or in reverse order to that of extraction.