in Movie edit pro 2014 exported and reimported frames change color

clement5 wrote on 1/8/2014, 12:55 PM

Since MEP balks at some Virtualdub filters and does not have rotoscoping capability, I have to export frames, edit them externally, and then reimport them.  In this process the color changes slightly.  This happens no matter the format of export.  MP3 shifts towards green with less red and often has higher brightness.  Huffy, a lossless codec also shows shifts, but they are different from that experienced with MP3.  I can not confirm if this happens on export or import.  The external editing does not change color because I can easily compare the output with the input.  Since I import the original file in Huffy format, exporting it in huffy and reimporting it should not change any information.

This would seem to be a bug in MEP which needs to be fixed.  I have never seen such shifts in external editors such as VirtualDub or Paint Shop Pro.  It happens all the time in MEP.  Sometimes the MP3 shift can be almost compensated by increasing the Red by 2 from 50 to 52, but the Huffy shifts are more complicated.

I am using a Compaq CQ5218F with AMD II X2 215, 7GB ram, Windows 7 and LG D3242P monitor, MEP 2014+.

Comments

cpc000cpc wrote on 1/9/2014, 3:36 AM

clement5,

I'd do some more test here to see if I get the same shifts you describe, but I'm a bit confused...

You say you are exporting 'frames' (that means to me individual still images eg JPG or BMP etc), but then you say the formats are MP3, an audio format, or Huffy (HuffYUV?) a video codec.What is your external editor and what format is being edited there? If I export either single frames as BMPs or a section of a clip as MPEG-4 video the results are indistinguishable for the original when re-imported into MEP

Regards,

Carl

 

clement5 wrote on 1/9/2014, 10:57 AM

Of course the single frames are exported using JPG, the MP3 was just a bad typo.  I work with a variety of audio/video formats and often deal with MP3, so there was an accidental mislabeling.  But for editing purposes I also have to export in Huffyuv format which is lossless provided the correct encoding is selected.  With the Huffy format I can remove defects from old films by cloning from one frame to another, in other words I can rotoscope using Photoshop CS3.  Also other types of editing are possible using VirtualDub filters which are incompatible with MEP.

Then I overlay the edited copy onto the copy I am editing.  MEP is much more convenient for this purpose.  But then I can turn the new layer off and on to view the changes.  When I do this there is a noticeable color shift and sometimes a brightness shift.  With black and white there is just a brightness shift.  This shift can also be seen when I step from a frame in the original to the new edited adjacent frame(s).  Sometimes the editing just involves removing a single spot on one part of the frame, but the shift is evident over the whole frame.

I just tried exporting and reimporting as an uncompressed video, and there is a slight color shift.  In the frames I selected it was very slight, but the exported video had slightly less red.  Next I took the original video in Huffyuv format and exported 6 frames as a test uncompressed using MEP.  I also exported the same 6 frames uncompressed using VirtualDub.  I brought the two test videos back into MEP and there was a large difference in the RED.  Then I viewed both sets of frames by importing them into VD and the difference was still there.  Soooo, I must conclude that the problem is with the export of frames.  Curiously the VD output is slightly smaller than the MEP output.  If MEP is looking encoding and looking at extra info this will be stripped off by editing processes.  But it should be able to export/import without any shifts.

In many pictures the problem is very subtle, but I picked a scene where I knew it would be very obvious.  I have not tried all output formats.