So-called "Lip-Sync" errors occur if the audio and the video signal is not in sync with each other, audio follows video behind or video follows audio behind. It is described and standardized in ITU-R BT.1359-1.
Maximum acceptable delay times between video and audio signals, as defined by the EBU (Recomm R37), ITU (J100), EBU (Tech 3311), ITU (R-BT1359):
|production step||max. delay time, video follows audio||max. delay time, audio follows video|
|production||5 ms||15 ms|
|international program exchange||20 ms||40 ms|
|distribution||40 ms||60 ms|
|at the end user||90 ms||185 ms|