Audio Video Buffers

[Lion]

I would like to help me find the right values to audio and video buffer options. This is critical for the final video's syncronization between audio and video.Here's my problem.When the values are not right,audio seems to be listening earlier than video does.And that's a real problem when i try to write a movie from my WINFAST TV2000 capture card.I have a Celeron 450 Mhz with 128 Mb Mem.If u think you know something about values of video-audio buffer sizes,please notify me.
Thanks!