Annex 5 to AVC-632R

ITU-T SG15 Experts Group	ISO/IEC JTC1/SC29/WG11	
Temporary Document No.12 rev (Paris)	MPEG94/133	
March 18, 1994	March 1994	

Source:	ITU-T SG15 Experts Group for Video Coding and Systems in ATM and Other Network Environments
Title:	Effects of jitter on audiovisual system operation
Purpose:	For information
Relevant sub-groups: Systems
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This document sets out how the jitter introduced in the network affects the performance of audiovisual system operation.  Though ATM is indicated as the source of jitter, the discussion is applicable to other sources of jitter.  It is noted that "timebase recovery" is meant here as reproduction of STC at the decoder by use of SCR/PCR.

1. Effects of jittered arrival of coded 
    information	==> additional buffer, hence additional 
        delay	
		
2. Effects of jittered arrival of timebase 
    information		
		
1) DTS with jitter		
		
• difference between writing and reading rates of the 
  buffer
         	==> additional buffer, hence additional 
        delay	
		
2) PTS with jitter		
		
• lip sync	==> visible distortion, largely tolerable	
• picture representation on display	==> visible artifacts	
		
3) sampling clock with jitter		
		
• color subcarrier in composite signal	==> visible color changes, stringent	
• audio reproduction	==> audible distortion, stringent