Capture Video with Lots of Flashes

[sammie]

Hi guys, I'm trying to capture some video to make a DVD for distribution. The video is a Hi-8 of a parade at night. The big issue is there are tons of flash bulbs going off. Everytime a flash bulb goes off I get frame drops, since there are lots of flashes................

I've tried with and without my TBC. I've tried my Hauppauge analog card, AVDC100 digital box and passing through my camcorder, nothing seems to prevent the frame drops. When the flash goes off, the video frame seems to feeze for a split second if I'm monitoring the capture, then the drops show up.

Any ideas on how to do a better job of capturing? I end up overall withabout 300 dropped frames in an hour of video. 5 seconds out of an hour probably wouldn't be bad. It's a parade so sound sync really isn't even much of an issue and I can easily correct that enough for people not to notice, it's that split second frozen immage that makes the problem obvious.

[sammie]

......as a PS, it's not my capture system. I capture lots of video with my set up and rarely if ever drop a frame normally.

[yoda313]

Hello,

Have you tried to turn down the brightness on your capture card???

Also, have you changed the bitrate??? Maybe lowering the video bitrate will lessen the impact of the high video source.

Kevin

[Capmaster]

You need a higher bitrate with flashing scenes, not lower.

Macro blocks are an indication of too low a bitrate and nothing generates macro blocks like flashing lights or bright fire scenes. I would imagine that the dropped frames are being generated for the same reason that macro blocks are formed ...an overwhelmed encoder

[sammie]

Yes, I've increased the bitrate to more than twice what I typically use to capture with no dropped frames. Didn't help. Tried lowering the bit rate too.........hey you get desperate you try stupid things. That didn't help.

I didn't try turning down the brightness. It's a parade at night so I'm a bit worried that would make things to dark to see. Even lightening it back up post-processing I'd probably end up losing a lot of detail. But I'll give it a shot.

No macroblocks present. It's strictly a whole frame freeze like the flash is somehow messing up the sync signal. Interestingly, the TBC box seems to make it a bit worse. It isn't completely predictable. I don't see the same numbers of frames dropped in the same places always, but I'd say I lose about 20% more frames with the TBC box in line.

[sammie]

@ Yoda.........actually, what it seems like I need is some sort of high cut choke or limiting filter. Is there some sort of box that does that anyone is aware of?

[yoda313]

@ Yoda.........actually, what it seems like I need is some sort of high cut choke or limiting filter. Is there some sort of box that does that anyone is aware of?

Hello,

Sorry, I'm not even sure what you're asking for. I don't do much filtering if any

Good luck.

Kevin

[sammie]

I don't do much filtering either (probably thus the question I guess something like a signal clamp that would just chop off or attenuate any signal that got "too high". There used to be things like that for recording audio, because when you would get, say a big cymbal crash the tape couldn't handle it and you'd get a distorted recording.

[Sillyname]

Aaaaah yes! Flashes! You're gonna have a hoot trying to compress your video to MPEG2, by the way. (Use TMPEG or spoon your eyes out!) I've had my share of strobe light -vs- compression problems. Didn't have trouble capturing though...

Sounds like your NTSC signal is too high at the flashes. You need to apply an NTSC filter to it while you capture. If your capture program is sophisticated enough, there should be an option to apply an NTSC color filter while you capture.

You could also try popping your Hi8 tape into a Digital8 and see if capturing it digitally through the camera's firewire makes a difference.

[SLK001]

It's not your system. It's your source. When the flashes occur, they cause the luminous levels to exceed the specification. With your source acting like that, your capture system has no hope of capturing this.

[sammie]

Aaaaah yes! Flashes! You're gonna have a hoot trying to compress your video to MPEG2, by the way. (Use TMPEG or spoon your eyes out!) I've had my share of strobe light -vs- compression problems. Didn't have trouble capturing though...

Sounds like your NTSC signal is too high at the flashes. You need to apply an NTSC filter to it while you capture. If your capture program is sophisticated enough, there should be an option to apply an NTSC color filter while you capture.

You could also try popping your Hi8 tape into a Digital8 and see if capturing it digitally through the camera's firewire makes a difference.

Actually, I've been able to do pretty well with the compression.......except for the freeze frame moments!

Exactly on the NTSC signal, and yes I probably need a "video clamp" is the term I'm coming accross while trying to Google up an answer. Of course all the ones I've found are >$8K so not something I need that badly. Which vid capture programs are you thinking? I typically use VDub for analog capture and to be honest it's been quite some time since I've monkied under the hood with things at that level on the capture side. I don't recall anything like you are suggesting though?

Yeah, I may have to borrow one that will play Hi-8 as digital out. I had a Sony video walkman that would do that, but somehow the firewire port got buggered on it. My camcorder will playback Hi-8 tapes, but won't do a digital out, only analog.

......as another PS...... I just read my title thread. Boy has this forum cleaned up it's act with no one picking up the potential double entendre there!!! And no, it's a kiddie Christmas parade not a Mardi Gras parade.

[SLK001]

......as another PS...... I just read my title thread. Boy has this forum cleaned up it's act with no one picking up the potential double entendre there!!!...

Hey, I came here hoping to see some T&A!

You might want to try to record your Hi-8 onto a VHS tape. The new recording may clean up the excess white levels (but, alas, there's that nasty extra loss of quality).

[sammie]

Ok, I just borrowed a friends LiteOn DVD recorder. Umm.......it did damn near perfect. I've been kind of ribbing him (a lot ) about going the brain dead route for capturing DVDs. I may have to try this thing a bit more this weekend to see if I've been too much into the geeky approach.

[yoda313]

Ok, I just borrowed a friends LiteOn DVD recorder. Umm.......it did damn near perfect. I've been kind of ribbing him (a lot ) about going the brain dead route for capturing DVDs. I may have to try this thing a bit more this weekend to see if I've been too much into the geeky approach.

Hello,

Don't ditch the "geeky approach" completely. Remember you can do so much more with bitrate settings and compression levels on a capture card then a standalone. And you can do menus much nicer on the computer and you wouldn't have to rip your standalone dvd to do it.

But I'm glad you found something that works for your situation

Kevin

[sammie]

@yoda313 Oh I agree. Not ready to pack it in yet. I had just kind of written those boxes off genericlly under the "this is too complex they can't possibly do a good job" banner. Truth is, it was pretty good and I don't just mean in the fixed the problem sense. I want to do some work to see how good it might be. I can't imagine using it for everything, but it's so easy that if it's decent (and right now it looks like it is) I could see doing it for a lot of quick and dirty things.

My biggest problem would be I tend to do a lot of post editing work on things. While you can do some now with MPEG files, clearly the way to go for high end editing is .avi , plus all my tools are biased that way.

I guess My message would just be don't dismiss the idiot boxes to quickly, they just might be getting decent.