Video and Sound Syncing

So I have been using DaVinci for about one year now and no problems as such ..... am all updated too.

The latest project I am working on -

I video myself singing along to a track which is in my ear on headphones on my iphone
I import the video in with the sound of my singing.
I import in the MP3 of me singing.
I sync the two and usually all fine -

But not this time - I have about 6 videos and none will sync as there seems to be some kind of time lag between the MP3 and the video sound ..... anyone know why this might be or how to solve it? As I say I am doing nothing differently to what I have done for the past year and never had this problem.

Thanks so much.

KatSinger,

No idea why there is a mp3 delay but if you have audio on the video clip you should be able to match
the waveforms of the audio ... just stretch out the timeline and match the peaks at one point. One possibility is that the FPS of the mp3 was not the same as the video ...

In the future ... clap on video and find that sound for both mp3 and video and sync ... you can move the video frame by frame to find the exact point of the clap and then match waveform peaks as above.

Thanks so much Bob Moore, and I have done lots of matching up over the past year and never had this problem hence my confusion!

It does sync at the start and then slowly as it plays the sync gap gets bigger and bigger ..... so starts off ok and then no longer is ok!

The most likely cause of this is that the iPhone video is variable frame rate.

Variable frame rate is a terrible invention and Resolve does not like it at all.

You may be able to save this by using a conversion program to change the video into a fixed frame rate format.