Force emby to play a file at 2.39:1 rather than 1.85:1

[jackthedoc 12]

All my searches have resulted in articles dealing with full-screen (4:3) vs 16:9 display and I simply cannot find if, and how, I can make Emby display an mkv file at the 2.39:1 ratio it should be using (other 16:9 settings display a squeezed image with pencil-thin people and squashed backgrounds).

If I open the file with VCL or PotPlayer, I can fine-tune the aspect ratio and view the film in the correct aspect ratio, but that feature does not seem to be present in the Emby gubbings: I did find the option to set ratio, but only option is Automatic... but this does not let me change 1.85 to 2.39 aspect ratio.

Any help would be appreciated.

I note that this is the only file that I have that displays the incorrect image, so I guess it's no big deal.

Thanks

John Norris

 

[Carlo 4561]

Hi,  What does the media info for this file show in the detail section of the media?
Can you grab a screen shot?

[jackthedoc 12]

Media Info

H:\Movies\The Devil's Rock 2012\The Devil's Rock 2012.mkv

MKV4476MB

 

videocamVideo

Title720p H264

CodecH264

AVCYes

ProfileHigh

Level41

Resolution1280x720

Aspect Ratio16:9

InterlacedNo

Framerate23.976

Bitrate7,477 kbps

Bit Depth8 bit

Pixel Formatyuv420p

Reference Frames1

audiotrackAudio

TitleEnglish DTS 5.1 (Default)

LanguageEnglish

CodecDTS

ProfileDTS

Layout5.1

Channels6 ch

Bitrate1,536 kbps

Sample Rate48,000 Hz

DefaultYes

 

I actually checked this before sending my original query.  I couldn't see anything regarding the actual aspect ratio, only that it has the dimensions of a 720p video at 16:9 ratio.

 

None of my video files has the aspect ratio formally stated, but when played they are always displayed at the correct 1.85:1 or 2.39:1 with the exception of this one....

[jackthedoc 12]

PS I always assumed that 16:9 was a shorthand for "widescreen format" without any actual reference to the "projected aspect ratio"; just as 4:3 was the old TV (academy) ratio. Is that not correct?

JN
 

[Carlo 4561]

So this media itself is 16:9 and that's the way it should be shown.

To answer your question 4:3 was the defacto standard used in broadcast TV for SD content.  Same with HDTV having a defacto standard of 16:9.
16:9 is what 99%+ of all TV are designed for to utilize the full screen.  On a TV like this showing any other aspect ration without stretching will put black bars on the sides or top/bottom.

These days you do see more and more films being available in other aspect ratios to give you the "cinema" experience.
I'm not usually a fan of wiki for these types of things as they often get things really wrong but this page isn't bad and is good for an overview on common aspect ratios and what they are typically used for:
https://en.wikipedia.org/wiki/Aspect_ratio_(image)

 

[visproduction 316]

1. Your original content at 1280 x 720 is 16:9 and the browser should play back that pixel aspect ratio correctly, but does not pay any attention to whatever squeeze or stretch is happening inside this 1280 x 720. Usually, this is not an issue.  Most video content of this size is using square pixels and is already formated correctly. A widescreen video 2.39, would have top and bottom black bars inside the 16:9 area.
2. mkv can use PAR settings inside the video file that forces a Aspect Ratio change for dedicated players, like VLC.  This forced aspect change is rare.  Any h264 content online should not have this, because browser playback ignores the internal PAR settings. You might run into this, if someone encoded into .mkv and fixed the playback AR, using internal file PAR settings, rather than resizing the width and height.  Forced PAR is more likely to happen from content pulled from a DVD, which has a built in problem of using 0.9 rectangluar pixels.
3. Emby encoding conversion probably accepts the PAR internal settings from a .mkv file and this probably results in proper playback from the transcoded video copy.  I have not tested this.
4. These internal PAR settings can be removed using mp4box software.  Although, that probably does not solve anything other than making the playback with VLC look wrong.
5. A lot of online content has incorrect AR. The preferred way to fix this, is to find the highest quality original master, crop out any black bars and then resize the cropped video back to it's correct AR.  For published content, you can look up the AR of the original if you are a member with imdb.org.  The AR is listed at the bottom of the content pages for members. Resetting the size of the video to it's correct AR is sort of tricky.  You have to pick even pixel sizes and it's very easy to get the AR off by a few percent.  You need to know which pixel sizes work.  To make matters worse, sometimes online content is not original AR and cropped to fill 16:9 TV's.
   
   I have a worksheet with calculators that helps you do cropping out black bars and resizing the content to the correct AR,  using AVIDemux. This calculator page goes very deep into AR issues.  But, it can also can double as a good way to fall alseep late at night.  Just read the first couple of pages.  Ha!   https://www.producerelease.com/blu-ray/parcalc.htm
   
   Hope that helps.

[jackthedoc 12]

Sincere thanks to the both of you for taking the time to explain these (sometimes opaque) facets of "movng picture" technology.

I will certainly have a look at the articles that you have provided in hypertext, Cayars and Visproduction, but I remain thankful that people like you can do what you do - otherwise, if it were up to me, the only "moving pictures" that we would have would be those flip the pages and watch the dog walk across the page...

Regards

John Norris

[Carlo 4561]

That's pretty funny. I guess those flip the page stick figures would be 4:3.  LOL

[pwhodges 2014]

To correct aspect ratio if it's not obvious I tend to look for a scene with a wheel or clock in it, or anything that should be round, and tweak the display aspect ratio in the header of the file using MKVToolNix by trial and error until it looks right...

Paul

[Carlo 4561]

That's a nice "round" way to solve the issue.

[jackthedoc 12]

I have used MKVToolNix for ages to incorporate spell-checked subtitle files into the mkv file but I was unaware of the function that pwhodges has recommended I try.

Again, thanks to all who have proffered suggestions to my query.

Regards

John Norris

[visproduction 316]

To figure out the correct AR on a problem video, sometimes I look for a starting logo for the company / studio.  Sometimes if it's a major release the actual title will be styled with a custom font.  Just getting the original title in a png and overlaying it to a screen shot can tell you if the AR is stretched.  All the large production companies have copies of their logos online just search for [company name] .png logo. 

Another easy one to check is the rotating earth or stars in a circle banner, or circle path of a flying fairy... recognizable logos that appear at the start of some content.  Copy paste a screen shot it to a photo editor and try to draw a square on top of the Earth or other perfect sphere, as a quick way to check if it's round or not.  3 pixels too wide left and right? Then reduce the video width by 6 pixels and rencode  a few seconds to test.

Looking into someone's eyes in a close up, can often spot the video is too wide or too thin.by the shape of their iris.  There is always car wheels in the background if you looking at the car from the side, straight on.  Same with a round clock directly facing back wall.  Some movies are shot with wide angle lenses that widen people very slightly at the edges.  Professional cinematohraphers know this and when they are using an anamorphic lens they try to keep actors away from the extreme sides of the frame.  Anyway, check for circles in the middle 3rd of the frame to avoid any slight stretching.

Usually just cropping out any black bars and then checking the pixel size against the ratio it should be works most of the time.  Sometimes I've seen old content pre -60's that had been slightly cropped and then resized and was still wrong often by around 5%.  You can do a screen grab, move it to photo editor and resize it back to what it's suppose to be and see how it looks.  Often the skinny faces pop-back to normal people and you know that this copy needs AR adjustment.

 

Hope that helps.