What issue arises from coding and compressing video and audio into separate elementary streams?

When coding and compressing video and audio into separate elementary streams, synchronization difficulties often arise. This occurs because audio and video are processed independently, leading to potential mismatches when they are played back together. For instance, if there is a delay in the audio stream or an issue with the timing of the video stream, the lip-sync can be adversely affected, resulting in a disjointed viewing experience.

Maintaining proper synchronization requires additional effort during both encoding and playback, such as ensuring that the timestamps for the audio and video align perfectly. If these streams are not synchronized appropriately, it can hinder the overall user experience, as the audio may lead or lag behind the video content. This is a crucial aspect in multimedia applications where precise timing is essential for effective communication and enjoyment of the content.