Export from STP to FCP drifts out of synch at DVinfo.net

Simon Wyndham · September 24th, 2009, 09:44 AM

Okay, heres the scenario,

I sent a multitrack project to STP2 from FCP6 and edited all my sound. My Project preferences in STP are set to 25fps and 48khz to match my FCP project.

In STP the sound plays back perfectly in sync with the picture. But when I export an AIFF file back to FCP it starts off in sync with the picture but gradually drifts waaaay out!

What the hell is going on with it? I've had issues with STP before, but not this one. The video is perfectly in sync with the video when played within STP, so how on earth is it managing to create an audio file of a different length and sync on output? It defies belief!

In STP the project is 01:17:18:06 long (01:00:00:00 being the start timecode) while the outputted AIFF file always ends up being 01:17:17:04, almost a second shorter in length!

Simon Wyndham · September 24th, 2009, 10:25 AM

Okay, working through this. There seems to have been a number of people who have come across this issue, but with no satisfactory solution.

However I think I might be getting somewhere, although I do not know how to go about solving it.

I played the file that STP outputted in iTunes. The file length is actually the correct length (ish) being labelled as 17:18 in length (17:18:333 to be precise if I go to "Get Info"). So I could be wrong, but it seems that FCP is being the funny one here and somehow importing the file wrongly, even though it is 48khz and all the settings on output from STP were correct. Is there a way to change how FCP treats audio files on import?

Simon Wyndham · September 24th, 2009, 10:29 AM

Okay, really starting to talk to myself here! Looking at the audio file in the Viewer in FCP, FCP reports the file as being 17:18 in length.

So this begs the question, why in the hell is FCP making it 17:17 when I put it onto the timeline?!

Just to double check. If I look at the audio file in the Browser it tells me that the file duration is 00:17:18;11. However if I put the file onto the timeline and right click and go to Item Properties then Timing it tells me that the length is 00:17:17:07

Stark raving bleedin' bonkers! And with a deadline approaching I can do well without this sort of crap.

Simon Wyndham · September 24th, 2009, 10:51 AM

Okay, for anyone that encounters this problem, a bit more digging seems to indicate that FCP has a really arse about tit way of handling audio only files such as aiff.

I imported my aiff file into Quicktime and exported as a Linear PCM 16-bit 48khz audio only .mov file. I then imported this into FCP. Hey presto my sound is now in sync!!

This really is a bodge way of having to get around this. I've not encountered it before. Don't suppose anyone else has and knows a way of getting around it on export from STP?

Ryan Mitchell · September 24th, 2009, 02:06 PM

I think I've seen this before and honestly I just changed the duration of the audio to exactly match the video - since I knew they were dead on. I figured for a one-second difference over 18 minutes, the stretch should not be noticeable at all...

September 24th, 2009, 09:44 AM	#1
Simon Wyndham Trustee Join Date: Dec 2003 Location: Malvern UK Posts: 1,931	Export from STP to FCP drifts out of synch Okay, heres the scenario, I sent a multitrack project to STP2 from FCP6 and edited all my sound. My Project preferences in STP are set to 25fps and 48khz to match my FCP project. In STP the sound plays back perfectly in sync with the picture. But when I export an AIFF file back to FCP it starts off in sync with the picture but gradually drifts waaaay out! What the hell is going on with it? I've had issues with STP before, but not this one. The video is perfectly in sync with the video when played within STP, so how on earth is it managing to create an audio file of a different length and sync on output? It defies belief! In STP the project is 01:17:18:06 long (01:00:00:00 being the start timecode) while the outputted AIFF file always ends up being 01:17:17:04, almost a second shorter in length!

September 24th, 2009, 10:25 AM	#2
Simon Wyndham Trustee Join Date: Dec 2003 Location: Malvern UK Posts: 1,931	Okay, working through this. There seems to have been a number of people who have come across this issue, but with no satisfactory solution. However I think I might be getting somewhere, although I do not know how to go about solving it. I played the file that STP outputted in iTunes. The file length is actually the correct length (ish) being labelled as 17:18 in length (17:18:333 to be precise if I go to "Get Info"). So I could be wrong, but it seems that FCP is being the funny one here and somehow importing the file wrongly, even though it is 48khz and all the settings on output from STP were correct. Is there a way to change how FCP treats audio files on import?

September 24th, 2009, 10:29 AM	#3
Simon Wyndham Trustee Join Date: Dec 2003 Location: Malvern UK Posts: 1,931	Okay, really starting to talk to myself here! Looking at the audio file in the Viewer in FCP, FCP reports the file as being 17:18 in length. So this begs the question, why in the hell is FCP making it 17:17 when I put it onto the timeline?! Just to double check. If I look at the audio file in the Browser it tells me that the file duration is 00:17:18;11. However if I put the file onto the timeline and right click and go to Item Properties then Timing it tells me that the length is 00:17:17:07 Stark raving bleedin' bonkers! And with a deadline approaching I can do well without this sort of crap.

September 24th, 2009, 10:51 AM	#4
Simon Wyndham Trustee Join Date: Dec 2003 Location: Malvern UK Posts: 1,931	Okay, for anyone that encounters this problem, a bit more digging seems to indicate that FCP has a really arse about tit way of handling audio only files such as aiff. I imported my aiff file into Quicktime and exported as a Linear PCM 16-bit 48khz audio only .mov file. I then imported this into FCP. Hey presto my sound is now in sync!! This really is a bodge way of having to get around this. I've not encountered it before. Don't suppose anyone else has and knows a way of getting around it on export from STP?

September 24th, 2009, 02:06 PM	#5
Ryan Mitchell Regular Crew Join Date: May 2008 Location: Austin, TX Posts: 120	I think I've seen this before and honestly I just changed the duration of the audio to exactly match the video - since I knew they were dead on. I figured for a one-second difference over 18 minutes, the stretch should not be noticeable at all...