Royalty free music is not syncing with FCP? HELP!!!

Question

Hey Everyone,
So this is an odd one. I've stepped in to help a friend who can't get the audio to line up from Royalty Free Music to sync with the video timeline of his project. It's a ballroom workout dvd where it's all one take. They used the mp3's downloaded from Royalty free Music.com and imported them into the timeline. What's odd is the tempo goes in and out of time with the dancer (who certainly isn't the issue with tempo). So it seems as if the tempo speeds up some and then is a little slower. They filmed this with only her mic on, and the dancer listening to a Sansa mp3 player.
My first fix was to convert all mp3's in QT to AIFF files. When I relined them up...same issue. One song would seem a little more in tempo, then another would seem off.
I would have also thought perhaps a processor issue on their Mac. Same issue with my PowerMAc and MacBook Pro. So I don't think that's it.... WHAT THE HECK IS GOING ON!!!???
Please help...thanks!

Answer 1

Hi -
The weak link in all of this appears to me to be the Sansa Mp3 player. It was not designed, nor should it have been, to maintain accurate speed playback. It is highly likely it was speed drifting during the duration of the playback. Even if it is 99% accurate, it would still be a second out of sync for every 100 seconds of playing - which is very apparent of syncing dance moves.
If you have ever seen or participated in a professional production in which music playback is an essential part, you will see the great lengths taken to preserve sync on the set and in the edit bay = with specialized audio playback devices that lock to the camera.
Also, I assuming that the talent listened to the Mp3 player with in ear headphones while the microphone was left open to record voice, so that you do not have a recording of the music in the clear to use in the edit and must use the sound files.
Two suggestions:
1) If the Sansa Mp3 player still has the material on it, hook it up to a camera and record the player playing the music to videotape. If you are very lucky, the player may playback in a similar way (with similar drifts in speed) to when it played back to the shoot. Digitize that video tape and see if the audio syncs any better. Most likely it won't, but this is worth a try and can be done fairly easily and is worth a shot.
2) Manually sync the head of each song, then see how far off it is at the end. You can adjust the playing speed of the sound file in FCP (with the new speed change window, you can just enter a new duration) and you will have to go through and keep adjusting until you get an acceptable level of sync. If the songs were crossfaded, you will need to establish sync then re-do the cross fades between the correctly synced tracks.
Hope this helps.