Digital 8 capture poor audio/video sync

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Digital 8 capture poor audio/video sync

I am capturing DV from a Digital 8 tape cassette using a SONY GV-D200 deck and iMovie 10.1.5. The firewire port on the Sony deck is connected to a Thunderbolt 2 port on a LaCie external hard drive using a firewire to thunderbolt converter. On long clips (50 minutes and longer) the video falls noticeably behind the audio. This seems to get worse the longer the clip.

Is there an issue with iMovie for long DV clips?

I can encode analog video output from the Sony deck using EyeTV and have not noticed any audio/video sync problem with long clips. But this involves a digital to analog to digital video conversion which I suspect degrades the quality of the video.

iMac, OS X Yosemite (10.10.1)

Posted on Apr 22, 2017 6:58 PM

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Answer 1

Apr 23, 2017 3:31 PM in response to RaiderJim

Two things you might try.

1 Change setting on GV D200 for TBC (Time Base Correction) from ON to OFF or OFF to ON.

2 Try importing into QuickTime.Use the Record feature in this link.

How to use QuickTime Player - Apple Support

Then,if OK, import this into iMovie

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Answer 2

RaiderJim Author

Level 1

18 points

Apr 23, 2017 3:49 PM in response to thesurreyfriends

Thanks for the reply.

The GV-D200 default for TBC is ON, but the Sony manual states that TBC is only for tapes recorded in Hi8 or standard 8 format. I was trying to get a bit for bit copy of the DV file recorded in Digital 8 format. I decided anyway to try iMovie to copy my tape with TBC OFF, but the video still fell way behind the audio as the clip progressed. I could see this happening in the iMovie window during the import. The file is not saved until the import is stopped, so what I saw in the preview during the import is what I got in the saved file. It looks like iMovie does not handle long clips well.

I tried the QuickTime import with maximum quality. The saved Apple ProRes file had good audio/video sync, but is not a bit for bit copy of the DV file on the tape. The bit rate of the ProRes file is much higher than the mp4 file saved by EyeTV. I could not see any noticeable difference in the quality of the video between these two formats, nor any noticeable difference relative to the iMovie saved DV file.

I'm still disappointed that iMovie did not work the way I thought it should.

Thanks for the tip about QuickTime.

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