ITU-R 717-1990 (WITHDRAWN) Tolerances for Transmission Time Differences Between the Vision and Sound Components of a Television Signal - Section CMTT E - Transmission of Signals with Multiplexing of Video, Sound and Data, and Signals of New Systems
that for any connection used for the international exchange of television signals the time difference between the sound and vision components should not exceed 20 ms if the sound is advanced with respect to the picture or 40 ms if the sound is delayed wit
ITU-R 717-1990 history
1990ITU-R 717-1990 (WITHDRAWN) Tolerances for Transmission Time Differences Between the Vision and Sound Components of a Television Signal - Section CMTT E - Transmission of Signals with Multiplexing of Video, Sound and Data, and Signals of New Systems