Video and audio not in sync

[amilajack]

When playing files that have a long duration, the audio and video become out of sync.

[duanyao]

Yes, it's a known problem. At the time I wrote this code, I have little experience in writing a video player, so the player just renders frames at the pace of FPS specified by the video file and doesn't try to sync with audio at all. I'm reading this tutorial recently and will see if I can fix it.