Author Topic: color issue during compilation  (Read 2167 times)

TriFith

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color issue during compilation
« on: January 27, 2016, 11:49:12 AM »
Hello everyone,
Hope this is the right place to ask you about my problem with color translation during complitaion in Avidemux 2.6.8.

I am generating videos from CAD simulation aplication and I need to reduce them because of size is too big to send it by email etc...
I am using Mpeg4 AVC (x264) video output and MP4 Muxer. After compilation there are colours changed significantly in .avi.
Attached are some samples of original colours and colours after compilation.

I have tried many setting of filters, or configuration setting, but I have failed to improve the result of compilation :(

If anyone can advice me what to change or what to do to keep colours same after compilation, it would be very hopefull for me.

Thank you for your time and for help.

Cheers TriFith

Jan Gruuthuse

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Re: color issue during compilation
« Reply #1 on: January 27, 2016, 12:14:01 PM »
Not certain about this:
- decreasing bit depth going from cad to avidemux. Video has 8 bit.
- colour space not matching Adobe,  ProPhoto, sRGB (video). Change colour space and render again. Use a small test with colours posing this problem
- Chroma subsampling  4:2:0, 4:2:2, ....
- try other container like mkv / mp4 instead of .avi

upload a 10 seconds - 1 minute sequence of your original cad rendered video (+-50 MB), developer(s) could eyeball it.

ps:- Use a free dropbox account, mega or similar webservice (free public access, without registration to download your uploaded video) thank you.
« Last Edit: January 27, 2016, 12:24:03 PM by Jan Gruuthuse »

TriFith

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Re: color issue during compilation
« Reply #2 on: January 27, 2016, 02:19:34 PM »
Thank you for reply Jan Gruuthuse,
unfortunatelly I am not too skilled with video rendering and setting, so I am not able to understand very well what do you mean.
I have already done some tests with rendering video from CAD software with different setting. The best quality I have made with codec Cinepak 1.10.0.11 used for rendering.
But after compilation with Avidemux the colours are more changed so I am not using it at this time.
I have also tried to use different extension/container.

On following link there is possible to download short preview of original and compiled video (used by already mentioned codec Cinepak and .flv container used).
http://www.uschovna.cz/zasilka/HJXUYJZ8GT7AUHEE-L73/

What I need to know is, what I have to set for parameters to get smaller video with 30fps and same colours.

Thanks again
TriFith

Jan Gruuthuse

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chroma inversion
« Reply #3 on: January 27, 2016, 02:43:18 PM »
source: Video filter Swap U and V
original image should look like this:

but is displayed as:


OK goes like this: load your (CAD) video (msvideo, ...)

Video Output
 [Mpeg4 AVC (x264)]
Filters
   [Video filter Manager] (window)
  Colors
    Swap UV (double click) -< should appear in Active Filters

  Transform
    Resample FPS (double click)
    New frame rate 31,00 change to 30,00

[Close]

Select container (Avi, ... whatever you need)
Save video, that's it.

See avidemux (1.7 MB) saved: Fanuc

enjoy avidemux ;)
« Last Edit: April 01, 2016, 07:26:57 AM by Jan Gruuthuse »

TriFith

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Re: color issue during compilation
« Reply #4 on: January 28, 2016, 01:02:15 PM »
Ou yeah!
You are awesome ;) thank you very much.
This is exactly what I need to do.

I am so happy now.

Thank you again for your time and your advice.

Have a great day.
TriFith