Mysterious green dot in Sony Handycam video - reason and removal?

jimhap · January 9, 2011, 10:42am

Hey everyone,

Basically, me and some friends gathered together to do a project. After filming, a friend sorted through the videos and discovered that there was a green dot at the top right corner of the screen. I recalled that when we were doing the filming, there was also a green dot on the screen… and it moved too! Being a compositor, I realized that it wasn’t a bad CCD spot - it’s a tracking marker! It’s not the tracking you’d think of though - if I moved up, it would move up; if i moved down, it would do down, and so on. Then it would return to the “middle” spot. It’s very nice… if I was doing some alternate reality game. Otherwise, it’s a major annoyance.

So:

For those who own such a camera, have you gotten rid of it? Is it an option on the camera that can be disabled? And after filming, can it be removed in the camera?
What could I do in Blender to remove that dot? The final result should look pretty much the same as the scene itself, sans green dot.

The_Happy_Friar · January 9, 2011, 11:14am

So when you put the video on your computer (DV, HDV, ACHVD, motion jpeg, etc?) it’s still there? Normally that stuff could be encoded in to the video as extra bits but it doesn’t show up visually.

jimhap · January 9, 2011, 11:27am

Yup, it’s still there. The screen while recording (I was the filmer) had the green dot too.

LazyCoder · January 9, 2011, 12:04pm

Uh… you sure this isn’t just a teeny tiny lens flare? A screencap would help.

jimhap · January 9, 2011, 1:33pm

I will try to get that to you asap. For now, all I can say is that the scene was pretty dark.

The_Happy_Friar · January 9, 2011, 6:28pm

I’d what to see it too. What format is the video? Handycam’s used to do DV & newer ones do HDV, but I’m not sure what other formats they do now.

jimhap · January 10, 2011, 4:43pm

This post has been corrected, disregard this post.

jimhap · January 10, 2011, 4:52pm

OK, so now I have plenty of information to share.

First off: the codec. It’s not DV, it’s MP[E]G.
FFMPEG’s verdict:

~/GreenSpot$ ffmpeg -i M2U00389.MPG
FFmpeg version SVN-r0.5.1-4:0.5.1-1ubuntu1, Copyright (c) 2000-2009 Fabrice Bellard, et al.
  configuration: --extra-version=4:0.5.1-1ubuntu1 --prefix=/usr --enable-avfilter --enable-avfilter-lavf --enable-vdpau --enable-bzlib --enable-libgsm --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-libvorbis --enable-pthreads --enable-zlib --disable-stripping --disable-vhook --enable-runtime-cpudetect --enable-gpl --enable-postproc --enable-swscale --enable-x11grab --enable-libdc1394 --enable-shared --disable-static
  libavutil     49.15. 0 / 49.15. 0
  libavcodec    52.20. 1 / 52.20. 1
  libavformat   52.31. 0 / 52.31. 0
  libavdevice   52. 1. 0 / 52. 1. 0
  libavfilter    0. 4. 0 /  0. 4. 0
  libswscale     0. 7. 1 /  0. 7. 1
  libpostproc   51. 2. 0 / 51. 2. 0
  built on Mar  4 2010 12:35:30, gcc: 4.4.3

Seems stream 0 codec frame rate differs from container frame rate: 59.94 (60000/1001) -&gt; 29.97 (30000/1001)
Input #0, mpeg, from 'M2U00389.MPG':
  Duration: 00:00:02.99, start: 0.108467, bitrate: 8764 kb/s
    Stream #0.0[0x1e0]: Video: mpeg2video, yuv420p, 720x480 [PAR 32:27 DAR 16:9], 9100 kb/s, 29.97 tbr, 90k tbn, 59.94 tbc
    Stream #0.1[0x80]: Audio: ac3, 48000 Hz, stereo, s16, 256 kb/s
At least one output file must be specified
~/GreenSpot$

MPEG isn’t really a problematic codec, so let’s look at some frames.

A picture is a thousand words:

Arrow shows the little green dot.

Another frame of a sample video, this time without an arrow so that you can see the movement of it.

Better yet, why not the video itself? It’s worth a million words!

Raw footage here: http://www.sendspace.com/file/j1fwmt

And of course, the not-so-helpful Sony “support” reaffirmed my prediction:

So yeah - it’s basically the camera’s fault, and there’s no way to remove it on the camera.

That said, can someone please tell me how to remove that pesky dot?

The_Happy_Friar · January 10, 2011, 6:42pm

If it’s always in the same place you could use a NLE to remove it. Blender most likely could but I don’t know how. I’m pretty sure I could do it in Vegas.

Daccy · January 10, 2011, 6:47pm

Here’s a rather hasty attempt:

http://www.sendspace.com/file/akcorw

It’s not perfect, but perhaps if you tweek it a little bit, you can make it work. Either that or find a better method.

jimhap · January 10, 2011, 8:01pm

NLE = non linear editor?
And yeah, Vegas is apparently a popular option for quick stop video cleaning. (A friend has a copy)

WOW… that’s the perfect fix! Thank you so much!
Of course, it’s not the best quality, but that’s what you expect from a quick fix.

Now could I ask you one last favor - could you do this in 2.49 instead of 2.5?
(I had terrible experiences with 2.5x betas - NEVER use it for production, just for fooling around with. With this mysterious video sequencer preview bug floating around, I certainly won’t try it this time around. :P) Thanks in advance!

Daccy · January 11, 2011, 4:21am

Unfortunately I don’t have 2.49. Besides, you should be able to simply open the file in 2.49. The method I used isn’t new, so there shouldn’t be any compatibility issues.

EDIT: You could also append the objects/nodes.