How to search for black frames?

[Fitz Townsend]

Hey guys, can anyone weigh in on whether it's possible to search for black frames in a clip? (or if I am even using the correct terminology, for the question? My search didn't turn up anything)

I'm recording and hour's worth of video straight, to reduce into a 'highlights' collage. After the subject says something interesting, I wanted to block the lens for 3 seconds as a visual 'slate.'

The reason I can't simply stop and start is that I'm running another cam, and the sync would kill me. And I'm busy doing things like asking questions.

I'm on Movie Studio 10, so PluralEyes isn't an option.


Any ideas? I'm open to other ideas, like tapping a mic on one of the cameras to make audio level spikes. Is there a search option for this? I know how redneck this sounds, but I need a simple solution... My cams don't have record markers/indexes, etc.

[Edward Troxel]

From a script point of view, a script can't "see" frames or audio peaks. So you'd need to do this visually.

If you turn on ALL icons on the events (instead of head/center/tail), you should be able to just scan the timeline for the black spots. You may need to zoom in on the timeline.

[Fitz Townsend]

Thanks, Edward.

Is there a plug-in which will do analysis to a log file or something of the sort? I'm new to video, but seems like a simple set of parameters... For audio, just a peak locator... for video, average frame luminance or something?

Scan method should work, though. Can't complain on a budget. Thanks for the tip about the icons.

[Edward Troxel]

I don't know of any plugins designed to do what you're looking for.

[Mike Kujbida]

Fitz, have you considered something really low tech?
Have someone stand next to you with a pen and piece of paper.
As you hear something interesting, then tell them the camera's record time and have them write it down for you.

[Gerald Webb]

Originally Posted by Mike Kujbida

Fitz, have you considered something really low tech?
Have someone stand next to you with a pen and piece of paper.
As you hear something interesting, then tell them the camera's record time and have them write it down for you.

Thats gold! The simplest is normally the best.
Or,
go with the audio, hit the mic 3 times, 3 clipped peaks on the timeline should be easy to see.

I read this a while back,
The Americans spent $20,000,000.00 dollars on developing a pen that can write upside down in space,
The Russians used a pencil.

Simple is nearly always better.

[Mike Kujbida]

Originally Posted by Gerald Webb

The Americans spent $20,000,000.00 dollars on developing a pen that can write upside down in space,
The Russians used a pencil.

Gerald, you just made my day :-)

[Craig Longman]

Originally Posted by Gerald Webb

The Americans spent $20,000,000.00 dollars on developing a pen that can write upside down in space,
The Russians used a pencil.

But, have you used one? They're REALLY cool pens =)

And (sorry, nerd alert) upside down or not in space doesn't matter much. But they can both write in near-zero G and upside down in full G. =)

[Jeff Harper]

Really great solution, Mike. I did some investigating of the space pen after you guys brought it up...fascinating reading on Wikipedia. Anyway, they're available for $20 on amazon...what a cool stocking stuffer! I'm going to order several. Thanks for the idea!

[Fitz Townsend]

Originally Posted by Mike Kujbida

Fitz, have you considered something really low tech?
Have someone stand next to you with a pen and piece of paper.
As you hear something interesting, then tell them the camera's record time and have them write it down for you.

omg, the flood gates opened. Haha... alright guys, I asked for it. If I had someone else on the job, I could do that. In fact, I could do that myself, but because I'm involved in the project, it's interruptive.

And I have thought about hitting the mic, but that can really hurt when you're wearing cans and you don't expect it.

One could also buy a very cheap stand alone audio recorder for the same purpose.


I'm used to working in audio, where we would cut the audio and slate the recording with tone, which shows up at a nice, square, visual rectangle on the audio timeline. And depending on duration, you can make nice huge thick blocks that keeps things super smooth when cutting. The prob with hitting the mic is that the peaks can get lost when you zoom out.

You guys probably think I'm lazy bastard, but this is not the sort of project where I'm logging takes with a clapper, etc. On a quick turnaround, small details like this can make or break the efficiency of a workflow, and thus determine whether a project is worthwhile or not, altogether.

Just sayin'.

[Seth Bloombaum]

Originally Posted by Fitz Townsend

...I'm used to working in audio, where we would cut the audio and slate the recording with tone, which shows up at a nice, square, visual rectangle on the audio timeline. And depending on duration, you can make nice huge thick blocks that keeps things super smooth when cutting...

Why not do this for video? Most field mixers have a tone generator you could switch on for a couple seconds.

You could build or have built a bloop box - just a tone generator that you'd lay in one channel of the audio.

Switch on camera bars for a couple of seconds.

Shine a flashlight in the lens for a couple of seconds.

Close the iris for a couple seconds.

Use time-of-day timecode, then look at your watch and scribble the time down when something good happens.

[Jeff Harper]

Originally Posted by Fitz Townsend

The prob with hitting the mic is that the peaks can get lost when you zoom out... You guys probably think I'm lazy bastard

The only thing easier than tapping on the microphone would be to have someone do everything for you. Yes audio peaks get lost when you zoom out...zoom in till you find them.

If it hurts when you clap in front of the mic with headphones on, take off the headphones.

Find the peaks, put a chapter marker or cut the clip, and your done.

[Jeremy Dallek]

How about a stopwatch that has a lap timer? start the stopwatch when you start the camera, and just hit the lap button at the critical points? there is probably a good phone app for this, where you can see all the lap times as a list at once on the screen. Hope this helps!!