Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Incorrect DAR of 2.40:1 instead of 2.39:1 ? #612

Open
Sami32 opened this issue Sep 16, 2017 · 3 comments · May be fixed by #829
Open

Incorrect DAR of 2.40:1 instead of 2.39:1 ? #612

Sami32 opened this issue Sep 16, 2017 · 3 comments · May be fixed by #829

Comments

@Sami32
Copy link
Contributor

Sami32 commented Sep 16, 2017 •
edited

https://en.wikipedia.org/wiki/Aspect_ratio_(image)

The motion picture industry convention assigns a value of 1.0 to the image’s height; an anamorphic frame (since 1970, 2.39:1) is often incorrectly described (rounded) as 2.40:1 or 2.40 ("two-four-oh").

This aspect ratio of 2.39:1 was confirmed by the most recent revision from August 1993 (SMPTE 195-1993).[5]

http://www.arri.com/?eID=registration&file_uid=7737

Unfortunately, everyone was so used to calling anamorphic films 2.35:1, that many still use that aspect ratio erroneously, even when talking about films shot after 1970. Similarly, 2.40:1 is an incorrect, unfortunate and unnecessary rounding up; a proper rounding up would be 2.4:1. The correct aspect ratio for anamorphic films shot after 1970 is 2.39:1.

Samples:
audio-issue-sample-file.mkv.txt

EDIT: Feel free to close this issue if it is not pertinent, relevant.
@Sami32 Sami32 changed the title DAR of 2.40:1 instead of 2.39:1 Incorrect DAR of 2.40:1 instead of 2.39:1 Sep 16, 2017
@Sami32 Sami32 changed the title Incorrect DAR of 2.40:1 instead of 2.39:1 Incorrect DAR of 2.40:1 instead of 2.39:1 ? Sep 16, 2017
kieranjol added a commit to kieranjol/MediaInfoLib that referenced this issue Mar 31, 2018
@kieranjol
File__analyze_streams.cpp - Change for 2.39:1 DisplayAspectRatio/String
eff9bb8 
MediaArea#612
@kieranjol kieranjol linked a pull request Mar 31, 2018 that will close this issue
Open
@kieranjol
Copy link
Contributor

Hi, I just noticed this issue. DisplayAspectRatio/String displays aspects ratios almost exactly how we would like:
mediainfo -f --Language=raw *.mov |grep -i aspectratio/string

DisplayAspectRatio/String        : 1.85:1
DisplayAspectRatio/String        : 4:3
DisplayAspectRatio/String        : 2.40:1
DisplayAspectRatio/String        : 16:9

The only exception being our 2048x858 DCP files, which have a ratio of 2.39:1 but it is listed here as 2.40:1. i've attempted to fix in #829

@mivk
Copy link

mivk commented Oct 4, 2020

Note that 2.40:1 is not just a rounding of 2.39. It is also actually used for BluRay. A scope film on a 2K DCP will be 2048 x 858 ( = 2.3869... =~ 2.39:1), but on BluRay it will be resized and cropped to 1920 x 800 = 2.40:1.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Assignees
No one assigned
Labels
None yet
Projects
None yet
Milestone
No milestone
Development

Successfully merging a pull request may close this issue.

File__analyze_streams.cpp - Change for 2.39:1 DisplayAspectRatio/Stri… kieranjol/MediaInfoLib
4 participants
@kieranjol @mivk @Sami32 and others