I am using video deluxe 2015 plus. I am capturing from the screen, but when I place the audio (an already existing audio file) this file is not in sync. Sampe sample rate and frame rate. The video goes fast or slow...I tried 25 frames and 15 frames.
Eduardo, I see no-one has responded to your question so I will attempt to offer some thoughts to help you.
First you say the audio file "already exists". Do you mean it was recorded separately from the video file? If so, the problem of the two files being out of sync is almost inevitable.
It might be helpful to us in attempting to help you if you would detail, step by step, exactly what you are doing to create your screen capture, including the software and any additional hardware you are using.