Source Device Latency Compensation for Audio Video Synchronization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing device chains for audio/video (AV) content transmission exhibit latency differences between audio and video content, leading to high buffering requirements and costs for audio and video renderers.
Innovation Solution
A method and system that utilize a Latency Indication Protocol (LIP) to determine and compensate for the latency difference between audio and video content, allowing the source device to delay either the audio or video content accordingly, thereby reducing the need for buffering in audio and video renderers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If audio content is transmitted in compressed format while video content is transmitted in uncompressed format, then transmission efficiency is improved, but audio latency increases due to additional decoding requirements
Solution Approach 1:
The source device performs preliminary actions by determining the audio latency and video latency separately, calculating their difference, and applying a delay to either audio or video content before transmission. This preliminary compensation ensures that latency differences are addressed proactively, preventing synchronization issues at the rendering devices and maintaining efficient compressed audio transmission.
2Reliability
If buffering is increased at audio renderer and/or video renderer to compensate for latency differences, then audio/video synchronization is improved, but device costs and complexity increase
Solution Approach 1:
The invention extracts the latency compensation function from the audio renderer and video renderer and relocates it to the source device. By determining latency information and applying delays at the source device before content transmission, the buffering requirements at the rendering devices are significantly reduced, thereby lowering their complexity and costs while maintaining synchronization reliability.
Solution Approach 2:
The source device acts as an intermediary that mediates the latency difference between audio and video streams. It determines the latency values, calculates the difference, and applies appropriate delays to either audio or video content before transmission, thereby compensating for synchronization issues without requiring large buffers at the rendering devices.
3Reliability
If latency compensation is performed at audio renderer and/or video renderer, then audio/video synchronization is improved, but buffering costs and device requirements increase
Solution Approach 1:
The source device performs preliminary latency compensation by determining audio and video latency values, calculating their difference, and applying delays to the respective content streams before transmission. This proactive approach at the source device eliminates the need for large buffering capacities at the rendering devices, thereby reducing the quantity of buffering resources required while maintaining synchronization.
Data Source
AI summary
The present document describes a method (500) for providing combined audio and video content from a source device (210) to an audio sink device (230) and to a video sink device (220). The method (500) comprises determining (501) latency information regarding the video latency for processing the video content and the audio latency for processing the audio content of the combined audio and video content along the device chain (100) between the source device (210) and the audio and video sink devices (220, 230). Furthermore, the method (5009 comprises delaying (502) the audio content or the video content in dependence of the latency information, and providing (503) the combined audio and video content with the delayed audio content or the delayed video content.