What are previews used for?

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Keith
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Joined: Sat Jan 24, 2015 7:56 am

What are previews used for?

Post by Keith » Sat Jan 24, 2015 8:02 am

I figured previews are useless when you're not using the gui, so I added --previews=0:0 to my handbrakecli script and it responded by giving me "libhb: scan thread found 0 valid title(s)". It took me quite a while to figure out that the change I made was what was causing the command to fail.

So, what IS handbrake doing with previews such that they are required even when running from the command line?

Smithcraft
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Re: What are previews used for?

Post by Smithcraft » Sat Jan 24, 2015 11:20 am

Handbrake is scanning the file to determine the cropping values, and maybe some other things that it might need to know about the file when it's doing the preview scans.

SC

AlBundy
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Re: What are previews used for?

Post by AlBundy » Sat Jan 24, 2015 7:36 pm

Is this really necessary because sometimes it takes really long to create the previews?
In my case I've disabled autocropping.

Al

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s55
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Re: What are previews used for?

Post by s55 » Sat Jan 24, 2015 9:28 pm

You can't disable. At best you can turn it down to a low number.

AlBundy
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Re: What are previews used for?

Post by AlBundy » Sun Jan 25, 2015 7:39 pm

Are there any sideeffects if I disable autocrop and turn down the previews?

Al

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s55
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Re: What are previews used for?

Post by s55 » Sun Jan 25, 2015 8:02 pm

no.

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Rodeo
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Re: What are previews used for?

Post by Rodeo » Sun Jan 25, 2015 9:00 pm

Yes, framerate detection will be less accurate (i.e. won't be adjusted for soft telecine), and if you have less than 5 previews, some very rare sources might fail to scan sometimes.

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