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HDV 1080i for Blue Screen – Blocky??
I’ve been fielding for info on the HDV codec board for the last few days, but have been getting little help there. I’m using Final Cut and suspect its possible that the problem is related to Final Cut, so I post here now. First off, this is my first time using HDV and we’re trying do a chroma key with it. The resulting image is alot more blocky than I was expecting, and I frankly don’t know if this is how things are supposed to look, or if I might have a setting wrong somewhere.
I put an image up below.
https://dadakingz.com/hikaku.jpgThis image is a comparitive image of what my shot looks like when working on it in Ultimatte AdvantEdge, and when I hit OK and the result in After Effects. It is sized down to 50% and this is the quality we’re getting. This is before choking of course, but this looks very incorrect.
Capturing was done with HDV 1080i 60i easy setup. Playback controls are set for High Quaility and 29.97 fps. Movies are output as reference movies.
I’ll try to follow up with another image at 100% before keying ASAP, but if anyone can tell me if this looks correct or has any idea as to what my problem might be, please chime in.
Thanks,
-bBen List
http://www.chromafresh.com -
10 Replies
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That’s all your compression from the HDV codec. All DV codecs are terrible for Chroma Key and I think HDV is right down there with regular DV. DVCPro HD pulls a pretty good key but even there I end up cutting masks to make the keys cleaner.
Chroma Key footage needs to be shot and captured uncompressed for the absolute best key.
Walter Biscardi, Jr.
Creative Genius, Biscardi Creative Media
https://www.biscardicreative.comNow in Production, “The Rough Cut,” https://www.theroughcutmovie.com
“I reject your reality and substitute my own!” – Adam Savage, Mythbusters
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Its hard to get comprehensive impressions of the quality of HDV for keying, as I suppose many are (wisely perhaps) not doing it. I recently ran across an opinion somewhere about how HDV was comparable to DVCPro50 for keying and as I had some really pretty amazing results with DVCPro50 recently and was therefore much more suspicious of my own settings. Thanks for the “grounded” opinion. Naturally I’d go uncompressed if we could afford it, unfortunately we’re in micro-budget territory here and are using what we have access to, a loaner basically. Hearing generally positive comments about quality for keying here and there perhaps raised our expectations a bit too high.
Anyway, our output will be to SD and at any rate, the HD-sized HDV footage looks too blocky to use, so the best compromise seems to be to reduce the footage size down in AE to 50% and output to lossless animation codec once, reimport and to pull a key from there. Resizing and reoutputting seems to take away some of the issues of 4:1:0 compression and I’d put our results so far somewhere between DV and DVCPro50 for working in this size. Its not nearly as bad.
We did try keying in HD size and reducing afterward. This is basically what was in the link in the first post. i.e. pretty hideous.
Anyway, thanks again for your thoughts!
-bBen List
http://www.chromafresh.com -
Ben,
Graeme Natress ( http://www.nattress.com ) makes a chroma filter for DV to reduce the “edgies” and smooth chroma of DV footage before applying the key. I am not sure he has tweaked the algorithm to suit HDV but it may be another solution for you if you are on a budget.
The thing is you will be adding some render time, but it might help you improve the chroma sampling of the HDV and get rid of the “blockies” before you try to key.
David
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I would recommend to use Motion chroma keying options as they are better than one included with FCP.
I did play with HDV footage in Motion and definitely chrome key looked better than your examples.Mariusz
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I’ve been doing a lot of testing with HDV and chromakeying of various sorts with different keyers. I have to, my job is virtual sets.
The short answer is don’t if you can help it.
The longer answer would be; I’ve managed to get a good key out of HDV using AdvantEdge and Chromatte (a special material), the only sample I have of this is here: https://www.virtualsetworks.com/movies/3dset.wmv (warning, movie is 1920×1080) and as you can tell is compressed, but still shows that the key is not that bad.
I’ve gotten a better key out of Ultra 2, which was designed to HDV footage, but doesn’t really apply here because it’s only available on the PC.Eric Pratt
http://www.virtualsetworks.com -
I have to say you seem to have pulled a pretty good key from the looks of it. Can you tell us how long it took to get the matte that clean?
Arnie
https://www.arniepix.com -
Not long, I used a matte tool to blur and contract the matte a bit downstream of AdvantEdge. I shot this on blue (my preference). Also, there’s a smaller version here if the other one was too big: https://www.virtualsetworks.com/movies/3dsetsmall.wmv
Eric Pratt
http://www.virtualsetworks.com -
Thanks all for your suggestions. It looks like Graeme Nattress doesn’t quite have the 4:2:0 upsampling thing quite together yet (at least as far as I can tell), though this looks like an interesting possible future solution. I managed to get myself all hyped up about the upcoming Panasonic AG-HVW200a, hopefully won’t have to wait too long for it to come out!!
Eric – Impressive key and at HD size too!! Nice!
I don’t suppose anyone recognizes the symptoms of our problem in AdvantEdge (see first image).
Namely that we can get a semi-decent key (albeit slightly blocky) on our footage within AdvantEdge, but upon hitting “OK” and viewing in After Effects, it goes super-blocky on us. For what its worth, going back into AdvantEdge we find that everything is now super-blocky within the AdvantEdge interface too. Resetting settings fixes it again, only until we hit the “OK” button again…BTW, if some of you wouldn’t mind, I put a 20MB piece of one of our media up on our web server. Please take a look and let me know if this looks right, or if you can manage a better, more natural key. I’m still not convinced that something isn’t wonky at our digitizing stage.
https://www.dadakingz.com/BLUE_CASE1_ILOVE2_HDV.mov
Incidentally and completely off topic, but one of our recent music videos will be in RESFEST this year. If any are curious, take a look at
https://www.dadakingz.com/movies/daedelus_justbriefly_S.movCheers all and thanks again for all chiming in!
-bBen List
http://www.chromafresh.com -
I
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try the g chromasharpen in the new film effects 2.5 It will help I think. I’ll post up a free demo when I get back from my holidays.
G
– http://www.nattress.com – Film Effects and Standards Conversion for FCP
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