Frame Sizes

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jep1955
Posts: 4
Joined: Fri Jan 13, 2017 1:57 am

Frame Sizes

#1 Post by jep1955 » Fri Jan 13, 2017 2:02 am

I did a search and could not find what I was looking for.

I have ripped a large number of DVD's and a few Blue Ray's. I feel I must be doing something wrong since if I right click on the .mkv file and look at properties, even the BD's show a frame size of (typically) 720x480. I would have expected 1920x1080 for BD and 1280x720 for DVD. What am I not understanding?

Woodstock
Posts: 10327
Joined: Sun Jul 24, 2011 11:21 pm

Re: Frame Sizes

#2 Post by Woodstock » Fri Jan 13, 2017 3:06 am

Quoting from the first site Google found for "DVD resolution":
720x480
Native DVD resolution is 720x480 for NTSC, and 720x576 for PAL, but there is an aspect flag that specifies whether it is full-screen (4:3) or wide-screen (16:9). Many (if not most) widescreen DVDs are not strictly 16:9, and will be either 1.85:1 or 2.35:1 (cinescope).
Bluray is 1920x1080.

These numbers are what is stored on the disk; there are flags and such that can fake other resolutions, but, to meet standards, that's what will be encoded. For example, the "wide screen" edition of a feature may actually only use 300 or 360 pixels high on a DVD, and the pixels will usually be "not square" (wider than high). There are terms like "anamorphic" to understand in all of this, if you REALLY want the tech stuff.

On Bluray, a lot of old TV series are "1080" high, but only 1440 wide, so they're still 4:3 ratio that TVs had "back then", but the base image on the BD is 1920x1080.

As for what is shown when you right-click - that depends upon the operating system and what you have installed. Windows can be pretty stupid about things, and assume that videos are ALWAYS one size. If you have VLC installed, start the video playing, and hit Ctrl-I for information, and it will show you better information than Windows will.

jep1955
Posts: 4
Joined: Fri Jan 13, 2017 1:57 am

Re: Frame Sizes

#3 Post by jep1955 » Fri Jan 13, 2017 10:16 pm

So, you're saying that I probably DO have BD mkv (1920x1080) files, but windows is just being stupid and saying "Oh -- Video. Must be 720x480"?

I was just curious since 720x480 SHOULD look pretty crappy on my 1080p monitor after upscaling!

I should note that I found it peculiar that windows said dvd rips and bd rips are ALL 720x480 (or 720x360, or whatever the aspect was for that movie)

jep1955
Posts: 4
Joined: Fri Jan 13, 2017 1:57 am

Re: Frame Sizes

#4 Post by jep1955 » Fri Jan 13, 2017 10:30 pm

Guess my point is, if the actual frame size is 720 pixels by 480 pixels, and my monitor is actually 1920 x 1080 pixels, native pixel>pixel display would be only about 40% of the screen. And if "expanded" to 1920x1080 it would be faking the resolution. My understanding is that BD (or 1080p tv) really is literally 1920x1080 pixels.

Anything else is cheating. A 4K video ripped can't be still 720 x 480. upscale would look like pooh.

MrVideo
Posts: 128
Joined: Sat Feb 27, 2016 2:31 am

Re: Frame Sizes

#5 Post by MrVideo » Sat Jan 14, 2017 7:46 am

jep1955 wrote:Guess my point is, if the actual frame size is 720 pixels by 480 pixels, and my monitor is actually 1920 x 1080 pixels, native pixel>pixel display would be only about 40% of the screen. And if "expanded" to 1920x1080 it would be faking the resolution. My understanding is that BD (or 1080p tv) really is literally 1920x1080 pixels.
Keep in mind that DVD MPEG-2 videos are not square pixels when doing any resolution conversions.
Anything else is cheating. A 4K video ripped can't be still 720 x 480. upscale would look like pooh.
Correct, it would 3840x2160.

Woodstock
Posts: 10327
Joined: Sun Jul 24, 2011 11:21 pm

Re: Frame Sizes

#6 Post by Woodstock » Sat Jan 14, 2017 4:20 pm

True, upscaling can look horrid.

But the key point is that files generated by MakeMKV are going to be copies of what is on the disk; it does not change the encoding or the resolution.

jep1955
Posts: 4
Joined: Fri Jan 13, 2017 1:57 am

Re: Frame Sizes

#7 Post by jep1955 » Sat Jan 14, 2017 11:13 pm

Which goes back to the beginning. Why is my BD rip showing 720x480? If it is rectangle pixels so 720 covers 1920 I don't have better "resolution" just more screen covered by the same number of pixels. Which would look like pooh.

Woodstock
Posts: 10327
Joined: Sun Jul 24, 2011 11:21 pm

Re: Frame Sizes

#8 Post by Woodstock » Sun Jan 15, 2017 12:07 am

That I can't tell you. I have never had a BD rip show up at less than 1920x1080, but I also do not rely upon Windows to tell me what the resolution is. I just tried asking for the properties of a recent BD rip, and Windows simply says it's a 32.4GB "VLC media file (mkv)", with none of the information that would be displayed if I looked at an MP4 file instead.

How big is the file? 250MB or so per minute seems to be about average for a BD movie. If it is truly 720x480 (DVD resolution), the number would be more like 60MB per minute.

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