[asabil]

Each RTP packet has a 32bit timestamp, and a 32 bit SSRC. Each "sender" in an RTP session must use the same SSRC, this is how synchronisation between audio and video streams from the same sender (lip-sync) is achieved.

The timestamps have a resolution defined by the clock rate communicated externally through a signalling channel.

[akira2501]

MPEG-TS allows for packaging multiple streams with independent time bases.

[ta1243]

For example audio at 48k and video at 90k. The problem with that being that as they wrap around at different times. So video wraps first, then audio wraps later, and this can happen several times over