Double system sound Sync issue

[Rafael Amador]

Lars,
Why are you working with REAL p24 sequences?
The PANAS do not make REAL p24.
Read here about DVCProHD 1080PA24.
https://documentation.apple.com/en/finalcutpro/professionalformatsandworkflows/index.html#chapter=3%26section=1%26tasks=true
rafael

http://www.nagavideo.com

[Matt Lyon]

Lars, the 100.1% speed change you are applying is consistent with the difference between 24.00/23.976 fps … in other words, standard audio pulldown that is used for film workflows. As described in my tutorial, this is happening because something is preventing the audio from importing properly, and FCP is applying the incorrect NTSC flag. Look for the telltale orange bars I describe overlayed on your audio files…

If you’re audio was being imported properly, the NTSC flag would be set to FALSE! So you need to revisit the steps you are taking when importing the audio, and figure out what is going wrong exactly. Your sequence preset should be set to a 23.98 frame rate. Try importing the files in a new, empty project and then dumping out a quick XML to verify the import worked.

I can’t imagine that disk speed is an issue, since you are doing a completely file based workflow, no? There is no “digitizing” to speak of.

I don’t have direct experience with the camera and audio recorder you mention, so I can’t say whether something specific to those devices is creating issues too.

Hope this helps,

Matt Lyon
Editor
Toronto

[Lars Fuchs]

[Rafael Amador] “Why are you working with REAL p24 sequences?”

I’m not. I only created one as a test, to see if it made any difference. It didnt’. The editing sequences I hace have been using, and the default sequence preset, have always been 23.98. Please note that I had this problem even in a DVCProHD 23.98 Sequence (ie, camera-native.)

I will read the link you gave now.
-Lars

[Lars Fuchs]

I tried to follow your tutorial to the letter. However I AM in an NTSC region, so I don’t want PAL sequences. With that in mind, here is a detailed explanation of the exact steps I’ve taken. (I wrote it down after each one, so I’m confident this is accurate.

Note, this is a long post with excruciating detail, so here’s the bullet: it didn’t work. I couldnt get them to be in sync.

Steps:
1) Downloaded Preference Manager
2) Backed up FCP preferences
3) Trashed FCP preferences (emptied Trash as instructed by PM)
4) Launched FCP.
5) Set new Default sequence as follows: DVCProHD 1080pA24 @ 23.98 fps.

6) Verified that the default sequence preset is 23.98 in Audio/Video Settings:

7) Imported .wav file, 48 kHz 16bit stereo file recorded on Tascam DR-40.
8) Imported video file from scratch disk. Had been previously imported via Log&Transfer. Verified it is DVCProHD 23.98:

9) Created two sequences: Seq 1 as DVCProHD 23.98, Seq 2 as Apple ProRes 1920×1080 23.98:

and

10) Located and added marker at sync-clap in video and audio clips.
11) Dragged video into Seq 1 Canvas (the DVCProHD Seq). Dragged audio into timeline and aligned markers. moved audio track until clap was perfectly in sync. Confirmed by listening – no phasing. HOWEVER it is audibly out of sync (phasing detectable by 10 minutes), getting progressively worse. The audio lags the video. There are NO RENDER BARS or color coding on either video or audio clips in the timeline:

12) Exported XML. Opened xml in TextEdit. Sequence and both clips are

13) Using Copy/Paste and Find/Replace all instances of TRUE were replaced with FALSE. I didn't change the timebase because 24 is correct. Then saved that xml file as a new copy.
14) Quit FCP. Relaunched FCP, but forgot to disable 'open last project', so project opened. disabled setting, quit and relaunched FCP with only untitled project 1 open. Saved that new project with new name.
15) Imported fixes xml file as instructed in tutorial, all options checked, settings on (auto)
SEQUENCE IS STIL OUT OF SYNC! Now I have green render bars on all audio clips!

16) as an experiment, in the xml file I changed ONLY the audio clips &ltntsc&gt parameter to FALSE, but left everything else TRUE. this got rid of the green render bars (See grab below) but IT WAS STILL OUT OF SYNC.

17) I saved this new xml import test project with a new name, closed it, and quit/relaunched FCP.
18) I reopened the project I created in steps 6/7 above. I closed the DVCProHD sequence (Seq 1) and opened the Apple ProRes sequence (Seq 2). Synced up the audio and video as before to the clap. No phasing in first several minutes, phasing progressively worsening until its badly out of sync by the end (70 minutes later.) THis is all same as before. Note that now the video had a green render bar, as expected from putting DVCProHD into a ProRes T/L.
19) Exported and XML of the ProRes sequence.
20) XML file shows that sequence, video and audio are all still &ltntsc&gtTRUE&lt/ntsc&gt and &lttimebase&gt24&lt/timebase&gt.
21) replaced all TRUE with FALSE , saved as a new xml file
22) saved and quit FCP. Relaunched FCP, created new project by SAVE As. Imported new xml file, Now both audio and video have green render bars. AND IT IS STILL OUT OF SYNC.

[Lars Fuchs]

I’ve spoken to the most experienced and knowledgeable production and post sound specialist I know (decades of experience, feature and tv credit list as long as my arm), and she tells me in no uncertain terms that the problem lies in the Tascam DR-40. As she puts it:

“Note, the DR-40 is well know for NOT running at precise speed. If you record a 12 minute take it could fall off as much as 2000 samples. This can be almost 2 frames by the 10 or 12 min mark. This can be very noticable. Over 71 minutes…. You’re screwed.”

I’m not going to run the recorder for more than 10 minutes at a time from now on. Also considering upgrading the recorder!

PS Does anyone know where I can find a resolver for a NAGRA III? I still have one of those running well, just no pilottone resolver alas 😉

[Matt Lyon]

Thanks for the update Lars,

That makes a lot of sense. I was re-reading the thread and was thinking that since you also had the sync problem with Adobe Premiere, that means the issue is likely with the source material, not the software. And given that your thorough testing could not fix the problem, it all makes sense now.

I love Nagras too! But have you tried the Zoom h4n recorder? It’s pretty good for the price! (Although I haven’t tried running it for a 70 minute take).

Matt Lyon
Editor
Toronto