Any software that can scan HDV for drop outs?

[Matt Thomas]

Well I've got some HDV footage that I capture and there are some drop outs in the footage which is causing my multicamera edit to go out of sync, I was just wondering if there was any software that could scan my footage for drop outs or could cut the footage up where the drop outs occur?

Or would ripping the footage again with scene detect on split the files when drop outs occur?

Edit.
Well I've just found out that the drop outs don't exsist on the tape, but only on the capture file, so I'm guessing CS5.5 has caused the drop out. I'll try ripping again with HDV Split.

[Andrew Smith]

I've found this sort of thing before. It makes me wonder if on a rip-snorter hex-core i7 with 24GB RAM you still need to nurse the thing through HDV capture on CS5.5 Premiere Pro for some reason.

One thing I have done is to completely turn off screen savers during capture. I haven't tested it, but the invoking of the screen saver was somewhat roughly coincidental with the HDV glitches. I too recaptured from tape to get clean results..

Andrew

[Andrew Smith]

Also, this tool has been around for a while and might be more nimble at running in the background etc (I'm looking at you, Premiere Pro) when capturing HDV.

HDVSplit utility for HDV capturing with scene split - HDV capture utility

Andrew

[Sareesh Sudhakaran]

You might also want to try a different hard drive for capture.

[Andrew Smith]

Yup. I do that. And a different physical drive it is, too.

Andrew

[Kevin Janisch]

The issue isn't the audio getting out of sync with the video. The issue is dropped frames and how your capture program deals with it. In my case, I'll sync up my two cams in Sony Vegas Pro and start to multicam. Low and behold, somewhere down the line the video is off by a few frames or sometimes seconds. I've learned to always duplicate my video tracks as a backup before doing multicam. I would have to go to my backups, resync the clips and create another multicam track from where I left off, each time thinking "What the heck?".

Turns out, it has to do with framing error tolerance of your capturing application. In my case HDVsplit is very tolerant and captures the entire tape and tries to correct the dropouts using intraframe information. So I get onevideo file from HDVsplit. The same tape captured in Sony Vegas gives me 4 different video files. Vegas is intolerant of framing errors and when it encounters dropouts, it creates another video file. Each of these video files is missing a few frames to sometimes a couple of seconds at the end of each video per GOP dropouts.

When you capture a tape with a tolerant app such as HDVsplit and apparently Premiere CS3, it does it's best to fill in the gaps but captures just the single video file. But what happens is you get freeze frames or jump skips where the dropouts are which is where the "out of sync" occurs. The gap created where the dropout occurs causes the shift. Sometimes a few frames, sometimes a few seconds.

Solution: For multicam shoots, capture with an intolerant app such as Sony Vegas Pro 8.0c which will create a new video clip when it encounters dropouts. This way you at least know where the dropouts are and can just sync accordingly.

For more details on the technicalities, read Ken Jarstad's posts here:

http://www.dvinfo.net/forum/what-hap...erate-now.html

[Peter D. Parker]

Matt, if you line up all your clips before going to multicam, check that the wav files are all in sync to the end of the timeline.

If they are not,work backwards and you'll find out where the dropout is/are. Cut the relevant clip and move it back into sync.

Peter

[Andrew Smith]

Actually, I think we might have a slightly different issue at play here.

Your sync issues are because the two (or more) cameras aren't gen-locked together. After about 30 to 45 minutes you will start to get noticeable frame drift (just a few frames) between the two cameras when it comes to editing. This happens due to very slight differences between the internal clocks of the cameras.

I've learnt to always have the master audio track attached to my main camera as it is with closeups that you will most notice the corresponding issues. You can get away with more when it comes to the wide shots.

Peter is spot on with how to fix the timeline.

Andrew

[Sareesh Sudhakaran]

Originally Posted by Matt Thomas

Edit.
Well I've just found out that the drop outs don't exsist on the tape, but only on the capture file, so I'm guessing CS5.5 has caused the drop out. I'll try ripping again with HDV Split.

Drop outs are usually caused by hardware, like a slow or inefficient hard drive setup or poor cables or connectors, etc. I don't see how software can cause dropouts.