Video Transcoder Timestamp Offset Synchronization

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Video transcoders face synchronization issues between input and output Presentation Timestamps (PTS) due to decoding and re-encoding processes, particularly during audio splicing, leading to potential mismatches in audio and video data timing.

Innovation Solution

A method and system where a video transcoder decodes and re-encodes video frames, embedding network presentation timestamps and comparing them with transcoder presentation timestamps to determine a timestamp offset, using a field programmable gate array to synchronize audio and video data by adjusting program clock references and presentation timestamps.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If video data is decoded and re-encoded through a transcoder, then format conversion is achieved, but presentation timestamp synchronization is lost

Engineering Contradiction:

Improveformat conversion capabilityVSAvoidpresentation timestamp accuracy

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent calculates the timestamp offset in advance by comparing input and output PTS values during the decoding and re-encoding process. This pre-calculated offset is then applied to subsequent output frames to maintain timestamp synchronization, allowing format conversion while preserving timing accuracy.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors the relationship between input and output presentation timestamps and uses this feedback to adjust the timestamp offset. By comparing actual PTS values and calculating deviations, the system dynamically corrects timestamp synchronization issues that arise during transcoding operations.

Inventive Principle:

Principle #23Feedback

2Adaptability or versatility

If audio splicing is performed to insert advertisements, then advertising functionality is enabled, but audio-video synchronization is disrupted

Engineering Contradiction:

Improveadvertisement insertion capabilityVSAvoidaudio-video synchronization

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent introduces an intermediary timestamp offset calculation mechanism that mediates between the audio splicing operations and video timestamp requirements. By calculating and applying the appropriate offset during advertisement insertion, the system enables ad delivery while maintaining audio-video synchronization through this intermediary adjustment layer.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Ease of operation

If presentation timestamps are adjusted during transcoding, then output timing can be controlled, but input stream timing is altered

Engineering Contradiction:

Improveoutput timing controlVSAvoidinput stream timing integrity

Core Design Contradiction:

Ease of operationVSStability of the object's composition

Solution Approach 1:

The patent segments the timestamp adjustment process into two distinct parts: preserving the original input PTS values for reference and calculating a separate offset for output timing control. This segmentation allows the system to maintain input stream timing integrity while still achieving precise output timing control through the offset mechanism.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentEP2752023B1Method to match input and output timestamps in a video encoder and advertisement inserter

Publication Date: 2019.12.25 GOOGLE TECHNOLOGY HOLDINGS LLC

Figure 1
Figure 2
Figure 3

AI summary

A method, a video processing system, and an electronic device are disclosed. A video transcoder may decode a compressed video data frame creating a decoded video data frame. The video transcoder may embed a network presentation timestamp in the decoded video data frame. The video transcoder may re-encode the decoded video data frame creating a transcoded video data frame. A field programmable gate array may compare the network presentation timestamp with a transcoder presentation timestamp to determine a timestamp offset.