How is anamorphic determined in the database?

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How is anamorphic determined in the database?

Postby Jason_Hall » 08 May 2018 05:44

Just wondering how you guys determine if a DVD is anamorphic or not. I know you're not just going off what the DVD sleeve says, since this is sometimes incorrect and it's stated on the comparison page.

Do you put the DVD into a player and visually determine if it's anamorphic?

Are there any tools available? It's not enough to simply load the ifo file into a program and look for 16:9 since that does not always mean anamorphic.

If a DVD player is able to determine if a title is anamorphic, surely there must be a tool that can automatically verify this.
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Re: How is anamorphic determined in the database?

Postby James-Masaki_Ryan » 08 May 2018 11:30

If a DVD is anamorphic, it is flagged for widescreen 16:9 playback. Widescreen movies will appear as normal on a wideacreen tv.
If a DVD is nonanamorphic, it is flagged for 4:3 TVs so widescreen movies on widescreen TVs have black bars on all sides
Of the frame.

You can tell mostly by looking. Check this post:
viewtopic.php?f=9&t=32492
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Re: How is anamorphic determined in the database?

Postby Markus_Lang » 08 May 2018 18:13

There are also some rare cases where a 4:3 feature is — incorrectly — presented in anamorphic format (16:9), like Ida. See this post for a screenshot. Such case is called “pillarboxed” and it wastes pixels (image resolution) pointlessly to the black bars.
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Re: How is anamorphic determined in the database?

Postby James-Masaki_Ryan » 08 May 2018 22:41

“Shin Dong-hun Animation Collection” which I reviewed a while back had the same - anamorphic 1.33:1, which is a rarity:
http://www.dvdcompare.net/review.php?rid=4357
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Re: How is anamorphic determined in the database?

Postby Eric_Cotenas » 09 May 2018 04:40

And those pilarboxed 1.33:1 dvds are listed as anamorphic with a note whereas 1.33:1 transfers stretched to 16:9 are listed as anamorphic 1.78:1 with a note about the flaw. The color version of lady Vengeance on the US dvd is not flagged for 16:9 and plays squeezed on 4:3 sets but actually looks correct on 16:9 monitors with the players default mode of stretching 4:3 to 16:9.
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Re: How is anamorphic determined in the database?

Postby Jason_Hall » 09 May 2018 05:34

Interesting stuff! I had no idea there could be 4:3 anamorphic video.

It seems like the only fool-proof way is a visual inspection. I did test a few DVDs and they were correctly reported but looks like that's not always going to be the case. I don't think any tool exists that will take a screenshot, strip out borders and determine aspect ratio, attempt to scale, again strip borders and determine aspect ratio, and then report the results.

ah well. Would've been nice :)
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Re: How is anamorphic determined in the database?

Postby Eric_Cotenas » 09 May 2018 06:03

Jason_Hall wrote:Interesting stuff! I had no idea there could be 4:3 anamorphic video.

It seems like the only fool-proof way is a visual inspection. I did test a few DVDs and they were correctly reported but looks like that's not always going to be the case. I don't think any tool exists that will take a screenshot, strip out borders and determine aspect ratio, attempt to scale, again strip borders and determine aspect ratio, and then report the results.

ah well. Would've been nice :)


DVD is a 4:3 format with the same pixels in 4:3 or 16:9. A correct 16:9 transfer is encoded squeezed (with more horizontal information in each square pixel while gaining resolution vertically that would be sacrificed to just black matting in 1.78:1 letterbox 4.3 and losing less with 2.35:1 since the player adds the black matte with 4:3 playback). A file flag stretches the native 4:3 to 16:9 just as a file flag in Dolby Digital 2.0 tracks will turn on ProLogic decoding if your receiver is set to automatic (which is why we add “Surround” only to 2.0 tracks that are flagged not 2.0 tracks that just sound good with ProLogic turned on).

Playing a dvd in VLC with the default window size (not clicked to fill the frame) should display the disc in 4:3 or 16:9, although the player can hiccup once in a while if the menu is 16:9 and the film 4:3 or vice versa like the UK dvd of La Captive which plays its 4:3 letterbox transfer stretched because the menu is anamorphic, although I haven’t checked that disc on newer versions of the player). The VLC screenshots will be 4:3 (720x540 NTSC or 768x576 PAL) or 16:9 (853x480 NTSC or 1024x576 PAL) and aspect ratio for matted films is determined by cropping the mattes away and dividing width by height).

High-definition is native 16:9 with a 1.78:1 image made up of square pixels requiring no squeezing but requiring pillarboxing for 1.66:1, 1.33:1, and narrower silent film formats like 1.19:1 (or Xavier Dolan’s 1:1 square format for his latest film)
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Re: How is anamorphic determined in the database?

Postby Markus_Lang » 10 May 2018 18:54

Jason_Hall wrote:It seems like the only fool-proof way is a visual inspection.
No. This must be checked using some software that shows the presence of the flag for the video stream, like DVDDecrypter:

Image

This title shows “16:9”. There is nothing mysterious here. This result will decide whether we will label a disc “anamoprhic” or “non-anamorphic”.
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