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Old May 4, 2010, 2:15 PM   #1
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Default K-7 Video compression darkens video

Right this has been bugging me for ages, and I just can't work out a solution, so thought I would ask here.

When I take HD video's with the K-7, the files are enormous, really far too big for practical storage, so I compress them with DivX/xVid/etc and the video's come out really, really dark. For example, here is a side-by-side screenshot of the same video, the left foliage is compressed, the right is the raw, massive video:

Probably not the best example, but gives you an idea.

I am using hardly any compression at all, it barely shaves off 1/4 of the file size.

Now normally I edit my video's with VirtualDub, but when I load the video's into this, they come out green(?)

If I try to play the video's with VLC Media Player, is moans that the index is broken and has to repair the file before it will play.

Now, before anyone suggests it's the camera, it did the exact same thing with the test footage I took with my original K-7 (the one with the dodgy lens mount)

Using iMovie *spit* the video comes out the right colour, but it can't output at a satisfactory compression ratio, it just looks like a rubbish YouTube video.

Basically, I am at the end of my tether, has anyone else had this problem? if not, what are you using to edit/compress your video's. I have used half a dozen different programs, various codecs (and tried outputting the raw video uncompressed, still the same effect)

I am pretty sure this is a result of the Motion JPG format the video's are in.


Bonus video screenshot, you can see the problem better here:

Last edited by Tachikoma; May 4, 2010 at 2:22 PM.
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Old May 4, 2010, 9:38 PM   #2
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Hopefully Jason will be by, he seems to be best at video. I've taken a couple of short ones with the idea of using iMovie to put them together but haven't been enthusiastic enough to actually do it. I've thought that if I upgrade Photoshop I'll buy the CS version with Premiere in it as I'm eligible for the academic pricing and that makes it affordable.
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Old May 4, 2010, 10:46 PM   #3
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I use either adobe premier or sony vegas for my compressions and video editing/rendering. I would say this compression looks standard for a consumer grade compression plugin. Perhaps you should apply an overall brightness filter to the video before rendering to counteract the darkening. Ive never had quite this much of an effect using the softwares mentioned but they were pricey. Sony and adobe both offer lower priced software packages that allow almost as much features and same iq for 1/7th of the price. You should be able to pick up something for 100 but you could look elsewhere for a better free compression plugin to integrate with your current software.

About the image coming in green it looks like you have some kind of incompatibility issues with the file type. Ive seen divx renderings come out green and pink before that play fine in other players. Try adjusting the video output to a diff format in a program that recognizes the format, then re upload it to try it again in VirtualDub.

I always keep the files at full size until rendering the final product, the more compressions the lesser the quality no matter what specified resolution, but im sure you know that

Im sorry I dont have any free suggestions for video compression/conversions, but im quite positive you can get what you have working, if all else fails windows movie maker isnt terrible.
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Old May 5, 2010, 2:51 AM   #4
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Thanks both!

Will see if there are trials for the packages you mentioned so I can confirm they work how I want before splashing the cash.

I prefer to use free software when possible, but I have searched online for this problem and can't find anything similar, so I assume it is like you said and just a compatibility problem.
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