The Don's Craptastic World A meta-level binary dude embedded to a multimedia proxy world!

VirtualDub: How to prevent asynchronous sound

According to some comments from here, here and in some of the Emails I get people sometime experience asynchronous sound. As I have speculated here, this is most likely due the CPU being overwhelmed with the whole encoding process. Let me try to explain, and bear in mind, this is just speculation based on nothing but my own suspicions.

When you set the threads in the x264 codec to fully utilize your CPU, meaning all cores, and then some, you make sure the CPU is working at its maximum capacity just for video processing.

If you then add audio to the pile, the CPU just hasn't got any resources to spare, and if it does, it does a miserable job, thus resulting in lag which translates in asynchronous sound.

If that is the case, lowering the numbers of threads in the x264 codec should fix it. This way you can have both audio and video encoding in one go. I haven't tried this method, because I employ a different solution.