Best practice for blu-ray cropping

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tucobenedito1
Posts: 24
Joined: Tue Oct 14, 2014 9:43 pm

Best practice for blu-ray cropping

Post by tucobenedito1 » Tue Feb 19, 2019 5:55 pm

Hi,

I am interested in guidance from the community regarding best practices for cropping blu-ray movies. In most cases, auto-cropping does the right thing, but there are a fair number of cases where it crops too much. The approach I am using is to work in the Dimensions tab:
* Cropping is set to Automatic
* Determine what the expected aspect ratio is from the disc itself.
* Set source width and height to match that aspect ratio if it is not already set correctly.
* If the output display size is different than the above expected aspect ratio, change cropping to custom and set left/right/top/bottom to force the cropping to match the source aspect ratio.
* At the end of this process, the display size will exactly match what the expected aspect ratio should be as set in source width/height.

This process seems to work for me to address the discs that auto cropping does not get correct. That said, I want to validate this is the right process to follow given I am encoding my complete library and do not want to have to do so again due to an error in my process doing improper cropping etc.

Thank you for the help

rollin_eng
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Re: Best practice for blu-ray cropping

Post by rollin_eng » Tue Feb 19, 2019 6:06 pm

If auto cropping is not working have you tried increasing the number of picture scans it does?

tucobenedito1
Posts: 24
Joined: Tue Oct 14, 2014 9:43 pm

Re: Best practice for blu-ray cropping

Post by tucobenedito1 » Tue Feb 19, 2019 6:44 pm

Thanks for responding. No, I have not as I did not know that was possible (it has been my assumption the number of image samples it takes is the issue but did not know how to change it). I see it a lot on "Game of Thrones", particularly with episodes that are primarily dark.

So, how do I change the number of picture scans it does?

Thank you

mduell
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Re: Best practice for blu-ray cropping

Post by mduell » Tue Feb 19, 2019 8:46 pm

It's a setting in preferences. I use 30 for everything and leave autocrop on for all encodes.

On the rare failure, I'll set manual cropping.

Woodstock
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Re: Best practice for blu-ray cropping

Post by Woodstock » Tue Feb 19, 2019 11:26 pm

Occasionally you will run into video that uses the letterbox area for subtitles; in those few cases, you may need to turn autocrop off and set the crop values to zeros, if you use the subtitles. If not, autocrop should be fine.

tucobenedito1
Posts: 24
Joined: Tue Oct 14, 2014 9:43 pm

Re: Best practice for blu-ray cropping

Post by tucobenedito1 » Wed Feb 20, 2019 12:53 am

Thank you both for your guidance. Very helpful.

This thread makes me wonder whether there is a best practices document written up that covers all of the things to look for? I never would have thought to look for a cropping issue like we've discussed here.

mduell
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Joined: Sat Apr 21, 2007 8:54 pm

Re: Best practice for blu-ray cropping

Post by mduell » Wed Feb 20, 2019 3:53 am


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