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Problems with Canon XH-A1 Footage
Hi Guys,
I just got some greenscreen footage which was shot in 1080p25 with a Canon XH-A1.
The guy who captured it said it was captured in Premiere CS4 with the HDV 25p preset.But somehow I’m really surprised because the image quality was terrible and I don’t know why.
Sure, HDV is crap, but some months ago I worked on some HDV footage from a much cheaper Sony FX-1 and it didn’t look as terrible as that:This is a still frame rendered from After Effects (the footage was interpreted as HDV 25p):
https://www.dinomuhic.com/temp/Dancing_01.png (2,5MB)
The next one is the same frame with just Keylight applied (standard settings, just picked up the green color next to his arm):
https://www.dinomuhic.com/temp/Dancing_02.png (250kb)
Here you can clearly see the horizontal lines and these are really buggings me since they should’t be there. Looks like some field-problem but it was recorded progressive.
I can correct it to some degree with some DV-fixing techniques and plug-ins but it still doesn’t look good.
So what to do you think went wrong? Or is anything wrong at all?
I really appreciate your help guys!
Dino Muhic – Media Producer
VFX – Motion Graphics – Web-Design – Or just ART
http://www.dinomuhic.com -
13 Replies
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Hi Dave,
thank you very much for your quick answer. So there’s hope…
Can I convert the MPEGs directly in After Effects, lets say as a proxy, or do I need to do it before importing it into AE?Dino Muhic – Media Producer
VFX – Motion Graphics – Web-Design – Or just ART
http://www.dinomuhic.com -
Looks like it has something to do with it being stretched to 1920. The HDV I get from Canon’s XLH1 is native 1440×1080. I’m guessing the XHA1 is the same…? Toggle the pixel aspect button in After Effects and see if it (the lines) goes away.
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The artifacts need to be deartifacted with magic bullet deartifactor or one built into a keyer such as primatte. Next time I suggest a grey shirt, bright red over bright green highly compressed doesn’t work in the dv and the NTSC world.
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aside from the problems of trying to key hdv, the footage looks interlaced…
looking at the edges of the head and arms of subject (which i assume are moving around) on the original image you can see interlacing. so the footage was most likely not shot as 25p. you might try interpreting the footage as interlaced (preserve edges) and see if those edges cleanup… but you’re still likely to run into edge issues with hdv’s 4:1:1 color sampling. if it is interlaced, enabling frame blending (frame mix) may help to smooth the edges just a bit more.
the hdv issue may also be compounded if the footage was captured as hdv, then exported as hdv… essentially being compressed twice. you might see if you can get a lossless export from premiere to avoid further loss after capture. as you said, hdv is crap, but maybe it will be less crappy this way.
Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW -
Thanks Kevin
Exactly this is what I was thinking, too.
Perhaps it was shot in 50i and then combined to a 25p image when captured in Premiere?
This would mean to re-capture it with 50i upper field and not with 25p as before.When I try to interpret it as interlaced (with preserved edges on) it just deletes every second line, doesn’t matter if I interpret it as upper or lower field.
Dino Muhic – Media Producer
VFX – Motion Graphics – Web-Design – Or just ART
http://www.dinomuhic.com -
I tried it and they don’t go away.
Dino Muhic – Media Producer
VFX – Motion Graphics – Web-Design – Or just ART
http://www.dinomuhic.com -
Yeah, the red shirt was really a bad idea. I see this now.
But it wouldnt be that bad if I didn’t have this field interpolation issues. Still trying to solve it by exporting a test clip from Premiere using the Media Encoder.In Premiere I do see the same field problems, really extreme. The footage is interpet as 25p in Premiere but when I right-click the footage in the timeline and choose Field Options -> Always Deinterlace it gets better. I assume it just deletes every second line and interpolates it again from the one above.
How would you convert the MPEGs to a different AE-friendly format?
It was all so easy until now…I don’t know what’s happening here
Dino Muhic – Media Producer
VFX – Motion Graphics – Web-Design – Or just ART
http://www.dinomuhic.com -
Hi Dino,
A few questions:
1) Did you capture/digitize the clip yourself or was it handed to you as data already?
2) Was the original footage shot in 25F or was it shot in 50i?
3) If it was shot in 25F was it played back during digitizing with a 25F compatible machine (XHA1-XLH1)?
4) What codec was used to capture it with? -
Hi Mark
1. It was handed over
2. 25F (progressive)
3. Yes, with a XH-A1
4. Standard MPEG HDV codec used in the Adobe Premiere Pro CS4 Presets (HDV 25p)Dino Muhic – Media Producer
VFX – Motion Graphics – Web-Design – Or just ART
http://www.dinomuhic.com -
Hey just wanted to throw my two cents in. I own the camera in question here, and I just wanted to let you know that the XH A1 does not film in 25p. only 60i 30p 24p(two modes of pull down). The problem most likely started from the moment he/she imported the footage as 25p. So I would recommend getting the footage re-imported if possible.
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