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View Full Version : MJPEG 422 test footage, green screen, etc



dpotuznik
06-13-2010, 11:32 AM
Hi,
i have made an rapid test whith the green screen .. it's Really coool
my footage it's not perfect but you really see the difference

my settings are

422 checked
Quality: 320,275,250,230
Table : 24,24,24,24


http://www.dpotuznik.com/gh1/mjpeg_unpatched.flv

http://www.dpotuznik.com/gh1/mjpeg_patched.flv

http://www.dpotuznik.com/gh1/greenScreen.jpg

testdasi
06-13-2010, 12:39 PM
What does the 422 and 420 mean?

Oedipax
06-13-2010, 12:41 PM
What does the 422 and 420 mean?

http://en.wikipedia.org/wiki/Chroma_subsampling

422 records more color information than 420 so for special applications like greenscreen it makes for better results and less time finessing masks and what not.

Oedipax
06-13-2010, 12:45 PM
And it definitely shows a big improvement in those FLV files. Thanks for doing a test, dpotuznik!

nobbystylus
06-13-2010, 02:12 PM
ahh.. you've thrown me now.. i'm doing a greenscreen shoot tomorrow morning.. must resist urge to tamper with settings before big shoot day.... erk

sammysammy
06-13-2010, 02:14 PM
so you guys think for sure its better overall to shoot mjpeg with the 422 rather than the new patched avchd 24p? im also about to do a greenscreen shot in a week

Oedipax
06-13-2010, 02:19 PM
so you guys think for sure its better overall to shoot mjpeg with the 422 rather than the new patched avchd 24p? im also about to do a greenscreen shot in a week

Only one way to find out! But my educated guess would be that 720p at 4:2:2 will trump 1080p at 4:2:0 where keying is concerned.

sammysammy
06-13-2010, 03:00 PM
thanks

dpotuznik
06-13-2010, 10:50 PM
hi,
I try to test soon with the AVCHD in 1080P and 720p.

but whith this setting in Mjpeg you have only about 4min recording on 8Gb Card

dpotuznik
06-13-2010, 11:21 PM
hi,
i made the new test,

http://www.dpotuznik.com/gh1/mjpeg_unpatched.flv
http://www.dpotuznik.com/gh1/mjpeg_patched.flv
http://www.dpotuznik.com/gh1/AVCHD1080p_unpatched.flv
http://www.dpotuznik.com/gh1/AVCHD1080p_patched.flv
http://www.dpotuznik.com/gh1/AVCHD720p_unpatched.flv
http://www.dpotuznik.com/gh1/AVCHD720p_patched.flv

in Mjpeg you see really the diffrence between patched and unpatched.
but in AVCHD it's work nice too. :)

my seeting for AVCHD
video buffer 40.000.000
video bitrate 50.000.000
Overall 52.000.000
Limiting Bitrate 60.000.000

androoow
06-15-2010, 12:44 PM
anyone tried shooting greenscreen stuff using GH13 , 4.2.2. and people??? cheers

dpotuznik
06-16-2010, 11:07 PM
hi,

i go to try maybe end this week, i have friend i have green studio.
Whait and see :)

Have nice day

wturber
06-17-2010, 03:15 PM
so you guys think for sure its better overall to shoot mjpeg with the 422 rather than the new patched avchd 24p? im also about to do a greenscreen shot in a week

Given that the 4:2:2 implementations and 4:2:0 implementation are otherwise equal, the 4:2:2 should be clearly better. That said, with MJPEG 1440 4:2:2 I see color moire that I don't see in in MJPEG 1440 4:2:0 or in AVCHD 24 with the "c" settings. So I'm far from convinced that there is actually a substantial benefit or even any benefit. You simply need to do some testing or rely on the testing of others. I wouldn't wait and try it for the first time on a shoot that mattered.

gauss256
07-07-2010, 10:49 AM
I have checked the box for 422, but is there any way to know for sure that the color space in my recordings is actually 4:2:2? None of my usual video tools seem to report on it.

Martin Koch
07-07-2010, 11:54 AM
I use VideoSpec (http://laurent.ettouati.free.fr/english/index.html) on a Mac.

PappasArts
07-07-2010, 02:09 PM
Given that the 4:2:2 implementations and 4:2:0 implementation are otherwise equal, the 4:2:2 should be clearly better. That said, with MJPEG 1440 4:2:2 I see color moire that I don't see in in MJPEG 1440 4:2:0 or in AVCHD 24 with the "c" settings. So I'm far from convinced that there is actually a substantial benefit or even any benefit. You simply need to do some testing or rely on the testing of others. I wouldn't wait and try it for the first time on a shoot that mattered.

I proved that many weeks ago. The 4:2:2 is not working as it should. Just Hi-bit Mjpeg alone records enough color info that it looks good. It adds unnecessary headroom.

Pappas

rambooc1
07-07-2010, 02:14 PM
Is that right Pappas. i'll gunna untick 422 right now.
thanks

rambooc1
07-08-2010, 01:19 AM
Pappas, the new Ptools notes has 422 as being functional. Are you sure it's not working?

R

PDR
07-09-2010, 10:55 AM
When I looked at 4:2:2 footage, it looked too blocky in AE to be true 4:2:2. I think the problem is Quicktime decoding on Windows (as usual)

When decoding through a proper decoder, colors aren't as blocky

This sample was downloaded from
http://vimeo.com/12854862

Nearest neighbor enlargement 3x , Left is native MOV in AE (through quicktime API decoder) , Right is though FFMPEG (libavcodec) . You can especially see along the right edge of the red stripe how "blocky" the colors are


http://i31.tinypic.com/vrr814.png



Papas - was there something else wrong with the 4:2:2 settings? or were you referring to the color only?