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kassysimon 09-26-2015 07:39 PM

Which ratio to rip discs to?
 
Hi all.

Im starting to rip my entire collection of DVD's and Blu Rays to MKV and im more confused after rading about aspect ratios than i was before and i am unsure of which pixel ratio is best for my set up. So here are my specs and questions.

I have the Panasonic PT-AE8000 and a 150" 2.35:1 screen.

I play through a HTPC via KODI.

I have tested a few rips at 1920 x 1080 and 1920 x 816 (for movies presented at 2.35:1 only) and they look the same.

Im guessing that the only difference is the black bars are encoded into the 1080's and not into the 816's. Is that right?

And which aspect ratio should i use?

Thanks guys.

Seegs108 09-27-2015 06:46 AM

Generally speaking what you're asking about are known as "re-encodes". I think the term "rip" is just confusing what you're asking about because in general to rip means to simply take off the information that's on the disc.

With that said, I'll explain. Typically when you see a movie in a matroska (MKV) container it's a re-encode. The tell tale sign is that it lacks black bars. This is done on purpose as it saves a little bit on the size of the re-encoded video. There's no point to encode that extra information as it never changes. Modern media players will automatically position that letterbox-less video information within the frame appropriately which restores the black bars on a 16/9 AR display. If you do see black bars encoded with the video information there's a 99.9% chance this is what's known as a remux, aka untouched video from the blu-ray. That 0.01% chance is if the encoder is a moron and doesn't know any better to crop out the black bar information when they re-encode the video. In general re-encodes do give slightly worse (and in some cases much worse) video quality compared to the blu-ray or a remux. This is because when re-encoding the video information it can be difficult to retain as much grain and detail from the bluray source, especially if the encoder is a newbie and doesn't really know much about encoding. But the benefit is, if encoded properly, you retain an unnoticeable difference in image quality at a much smaller file size.

With the Panasonic are you zooming or using an anamorphic lens to fill your 2.35:1 screen? If you're zooming you shouldn't have to do anything to fill your screen properly as your media player should still frame that 1920 x 816 video file properly with black bars. If you're using an anamorphic lens you'll still need to do vertical stretch/scaling along with your anamorphic lens. KODI should offer an appropriate scaling mode. If not, you can always use an external media player with KODI. I've done this in the past with MPC-HC and it's worked flawlessly.

kassysimon 09-27-2015 07:09 AM

Thank you so much. That is hands down the best explanation I've ever read.
Thank you so much.


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cansari 10-01-2015 09:37 AM

Quote:

Originally Posted by kassysimon (Post 37601417)

I have the Panasonic PT-AE8000 and a 150" 2.35:1 screen.

.


Is your projected image on such a large screen very dim? According to the calculator, you would be around the 9 fl range. Thanks.

Dominic Chan 10-01-2015 04:26 PM

Quote:

Originally Posted by kassysimon (Post 37601417)
Im starting to rip my entire collection of DVD's and Blu Rays to MKV and im more confused after rading about aspect ratios than i was before and i am unsure of which pixel ratio is best for my set up.

For Anamorphic widescreen DVDs, there are no black bars stored on the disc. The contents are stored in 720x480 resolution with rectangular pixels, so no cropping should be done during ripping (unlike ripping Blu-ray discs, which do have black bars that should be cropped out.

kassysimon 10-01-2015 08:03 PM

Quote:

Originally Posted by cansari (Post 37712737)
Is your projected image on such a large screen very dim? According to the calculator, you would be around the 9 fl range. Thanks.


Hi there.
The blacks are slightly washed out but it's hardly noticeable and I think that is mostly from light infiltration.



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kassysimon 10-01-2015 08:03 PM

Quote:

Originally Posted by Dominic Chan (Post 37724041)
For Anamorphic widescreen DVDs, there are no black bars stored on the disc. The contents are stored in 720x480 resolution with rectangular pixels, so no cropping should be done during ripping (unlike ripping Blu-ray discs, which do have black bars that should be cropped out.


Thank you.


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stanger89 10-02-2015 06:04 AM

Quote:

Originally Posted by Dominic Chan (Post 37724041)
For Anamorphic widescreen DVDs, there are no black bars stored on the disc. The contents are stored in 720x480 resolution with rectangular pixels, so no cropping should be done during ripping (unlike ripping Blu-ray discs, which do have black bars that should be cropped out.

That's not quite true, or it's not that simple. Anamorphic DVDs use a 720x480 grid to represent a 16:9 area, films that are wider than 16:9 still have bars stored on the disk.

The real question for the OP, is if you've got a big, scope projection setup, why are you re-encoding your discs when you rip, doing so necessarily reduces the quality.

Dominic Chan 10-02-2015 07:25 AM

Quote:

Originally Posted by stanger89 (Post 37735297)
That's not quite true, or it's not that simple. Anamorphic DVDs use a 720x480 grid to represent a 16:9 area, films that are wider than 16:9 still have bars stored on the disk.

Thanks for the clarification. My previous post regarding anamorphic applied only back in those days when 16:9 was considered "widescreen".
Quote:

The real question for the OP, is if you've got a big, scope projection setup, why are you re-encoding your discs when you rip, doing so necessarily reduces the quality.
Wouldn't be removal of black bars be the reason for re-encoding?

stanger89 10-02-2015 08:08 AM

Quote:

Originally Posted by Dominic Chan (Post 37735825)
Wouldn't be removal of black bars be the reason for re-encoding?

Maybe, but it's not a good reason. Compression is very efficient for static content, like black bars, you're unlikely to save any significant space by removing them, but in the process of re-encoding you compound the losses due to the lossy compression algorithms used.

Dominic Chan 10-02-2015 09:06 AM

Quote:

Originally Posted by stanger89 (Post 37737809)
Maybe, but it's not a good reason. Compression is very efficient for static content, like black bars, you're unlikely to save any significant space by removing them, but in the process of re-encoding you compound the losses due to the lossy compression algorithms used.

Other than the file size (which shouldn't be an issue according to your explanation), having the black bar can also "screw up" the positioning of the caption. I have a 2.35:1 screen and told Kodi to place the subtitle on the bottom of the video. If the black bars are not removed from the video, Kodi would place the subtitle on the bottom black bar, which will fall outside the screen area.

stanger89 10-02-2015 09:11 AM

You can shift them in Kodi though right?

Dominic Chan 10-02-2015 09:35 AM

Quote:

Originally Posted by stanger89 (Post 37739513)
You can shift them in Kodi though right?

The available options for subtitle position are:
-Fixed
-Above Video
-Top of Video
-Below Video
-Bottom of Video

I haven't looked for any additional option to shift the subtitle, but even if there is one, it would be a nuissance to have to shift them individually for each aspect ratio.

kassysimon 10-02-2015 10:29 PM

Quote:

Originally Posted by Dominic Chan (Post 37739353)
Other than the file size (which shouldn't be an issue according to your explanation), having the black bar can also "screw up" the positioning of the caption. I have a 2.35:1 screen and told Kodi to place the subtitle on the bottom of the video. If the black bars are not removed from the video, Kodi would place the subtitle on the bottom black bar, which will fall outside the screen area.


This is what got me starting this thread.
I remuxed a bluray, played it through Kodi and the subtitles where off the screen.
I wanted to re-encode the movie
to remove the black bars to ensure the subtitles position was consistent.




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kassysimon 10-02-2015 10:38 PM

Quote:

Originally Posted by Seegs108 (Post 37606770)
Generally speaking what you're asking about are known as "re-encodes". I think the term "rip" is just confusing what you're asking about because in general to rip means to simply take off the information that's on the disc.

With that said, I'll explain. Typically when you see a movie in a matroska (MKV) container it's a re-encode. The tell tale sign is that it lacks black bars. This is done on purpose as it saves a little bit on the size of the re-encoded video. There's no point to encode that extra information as it never changes. Modern media players will automatically position that letterbox-less video information within the frame appropriately which restores the black bars on a 16/9 AR display. If you do see black bars encoded with the video information there's a 99.9% chance this is what's known as a remux, aka untouched video from the blu-ray. That 0.01% chance is if the encoder is a moron and doesn't know any better to crop out the black bar information when they re-encode the video. In general re-encodes do give slightly worse (and in some cases much worse) video quality compared to the blu-ray or a remux. This is because when re-encoding the video information it can be difficult to retain as much grain and detail from the bluray source, especially if the encoder is a newbie and doesn't really know much about encoding. But the benefit is, if encoded properly, you retain an unnoticeable difference in image quality at a much smaller file size.

With the Panasonic are you zooming or using an anamorphic lens to fill your 2.35:1 screen? If you're zooming you shouldn't have to do anything to fill your screen properly as your media player should still frame that 1920 x 816 video file properly with black bars. If you're using an anamorphic lens you'll still need to do vertical stretch/scaling along with your anamorphic lens. KODI should offer an appropriate scaling mode. If not, you can always use an external media player with KODI. I've done this in the past with MPC-HC and it's worked flawlessly.


Hey seegs.
Just a couple of questions to clarify;

In relation to your question: yes I'm using the zoom feature. This works fine for a 1920x1080 and a 1920x816.

I'm still a little confused with these two sizes though. Is the 1920x816 the same file as the 1920x1080 but just with the black bars removed?

Thanks again.




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Seegs108 10-02-2015 10:48 PM

Quote:

Originally Posted by kassysimon (Post 37759769)
Hey seegs.
Just a couple of questions to clarify;

In relation to your question: yes I'm using the zoom feature. This works fine for a 1920x1080 and a 1920x816.

I'm still a little confused with these two sizes though. Is the 1920x816 the same file as the 1920x1080 but just with the black bars removed?

Thanks again.




Sent from my iPad using Tapatalk

The files are not the same. The movie, yes, but not the file. To remove the black bars the original video information needs to be re-encoded. They crop out the black bars and encode the video file with however many vertical lines of pixels there are left. It isn't always 816 as cinemascope movies vary slightly in aspect ratio. There are 2.35:1, 2.39:1, 2.40:1 and a few others. You'll also see the same thing when the movie is flat 1.85:1, but they only have to crop out 20 vertical lines from the top and bottom for this aspect ratio. So the video is altered and a small downgrade in picture quality does occur as it's extremely difficult to get a "transparent" re-encode of the original blu-ray video information. The better encoders out there tend to do a very good job and for most people the new file is more than good enough in quality to keep over the blu-ray remux as it's typically much smaller in size. The small downgrade in PQ is worth it to them as it saves a ton of harddrive space.

kassysimon 10-02-2015 10:51 PM

Gotcha!
Thanks again.


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Dominic Chan 10-03-2015 08:23 AM

Quote:

Originally Posted by kassysimon (Post 37759657)
I remuxed a bluray, played it through Kodi and the subtitles where off the screen.
I wanted to re-encode the movie
to remove the black bars to ensure the subtitles position was consistent.

Changing the topic slightly, have you found any other media player (software or set-top box) that has this feature of positioning the subtitles?

kassysimon 10-07-2015 05:37 AM

MPCHC does it.


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Dominic Chan 10-08-2015 08:56 AM

Quote:

Originally Posted by kassysimon (Post 37867945)
MPCHC does it.

I only find the option "Apply aspect ratio compensation for anamorphic videos" in MPC-HC, but it doesn't do what I want, which is to place the subtitle at the bottom of the video, regardless of the aspect ratio.

Is there any setting I overlooked?

kassysimon 10-08-2015 06:01 PM

Whilst playing a movie; right click. Subtitles. And there is check boxes to relocate to preset location or another option to set your own location.
I'm away for a few days. Let me know how you go. If you still can't find it I'll screen shot a quick guide for you.


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Dominic Chan 10-09-2015 11:43 AM

Quote:

Originally Posted by kassysimon (Post 37918433)
Whilst playing a movie; right click. Subtitles. And there is check boxes to relocate to preset location or another option to set your own location.

Kodi lets you specify the subtitle position in general terms such as "Bottom of Video", "Below Video" which once set according to preference, does not need to be changed when watching movies of different aspect ratios.

For MPC-HC, I have found ways to manually place or adjust the subtitles, but nothing equivalent to the Kodi way.

RLBURNSIDE 10-24-2015 09:01 AM

Quote:

Originally Posted by Dominic Chan (Post 37724041)
For Anamorphic widescreen DVDs, there are no black bars stored on the disc. The contents are stored in 720x480 resolution with rectangular pixels, so no cropping should be done during ripping (unlike ripping Blu-ray discs, which do have black bars that should be cropped out.

Dumbest design decision ever. It's not like Blurays were designed to be played back without the player being capable of extensive processing built-in as a base assumption (Java, for example). They could easily have added an aspect ratio value at the beginning of each video track and served the entire market that way for years to come.

/sigh


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