That is to say, I am not confused about what resolution IS, rather I am confused about what I am seeing.
So, I have just ripped my Spartacus S2 DVD's with MakeMKV, and then went on to convert the first episode with StaxRip, using its filmHQ setting, also had to change the FPS to 23.976.
It all converted fine, looks great, except, that the converted file is about 20 pixels wider than the original. When I viewed the media information within VLC for both the original and the converted file they both said the video was 720x480. Well, obviously one of them was wrong, so I took a print screen of both files and received even weirder news, instead of either of the videos being anywhere near 720 in width, they were both at least 850 ... Though, the height was the expected 480.
So my question is ... What the hell am I doing wrong?!
Thank you for any help, and my apologies for my stupidity.
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Thread: Confused about resolutions...
Read http://www.doom9.org/index.html?/aspectratios.htm how dvd is stored.
What is your staxrip converted video file resolution/frame size and display aspect ratio? Identify it with mediainfo.
It could for example be same as your dvd(720x480 16:9/4:3) or resized to a 16:9 frame size(~720x406 1:1) or cropped black borders and resized to 2.4:1 (~720x300 1:1)....
Hey Baldrick! Thanks for your quick reply. So I read up on the aspect ratios page you linked to and learned that, unsurprisingly 720x480 is a ridiculous height to width ratio, which I had never really thought about till now ... lol, and also learned that my video size of 850 ish is correct.
On that note, kudos to me, however, there is still my issue of the mismatched resolutions from the before and after. I uploaded the two Media Info pages I took, at your suggestion, though both seem to state 720*480 and 16:9, unless I missed something super obvious, neither are describing the actual size?
I also uploaded a comparison image if you (or anyone else) is curious.
I will definitely continue to look at my StaxRip settings to see if I have inadvertently missed some options or something.
Spartacus - Media Info - Original
Spartacus - Media Info - Converted
Spartacus - Comparison image
Last edited by geta-ve; 10th Feb 2013 at 12:03.
LOL. Oops! Silly me, I had pasted the personal DropBox links into the thread. I apologize! Links should be working now.
Oh I was missing what you wanted to know. 720x480 = A/R 1.5 (your input) 853x480 = D/A/R 1.7777777778 = 16x9 (your output). You actually wanted to see that it said 853x480 it depends on the writing lib to display that and what to display.
Thanks for the reply! My source file is definitely 853x480, but the output is 870ish x 480. I have scoured StaxRip for any obvious option that will fix this, or eliminate the issue, but nothing is coming up. Granted I have no clue what half of the settings do, especially in the Codec configuration, so there could be some silly little option that I am simply missing.
I would have thought however, that, what goes in, comes out... ? But, you know what thought did (shit the bed and thought he didn't!) lol.
As far as I can tell the output aspect ratio (as set in StaxRip) is the same as the input.
Sorry gents, I realize how silly this thread must seem.
Thank you though for your patience and time.
I am only using StaxRip because I wanted to convert to x264, and for some reason xmedia recode wasn't allowing me to... If there is an easier program, or something else that will automate conversion and give me a GOOD result (not great as I realize automating conversions will never give me great results, gotta be one of you guru's around here for that... lol), then I am all for that.
Anyway, whether the playback resolution is ~853x480 or ~874x480 depends on whether or not you use ITU resizing. Apparently StaxRip does, although there may be a way to turn it off or have it use non-ITU resizing or change the PAR. Like Wolfen, I've never used the program. As for whether or not ITU resizing should be used, that's a whole different can of worms.
Last edited by manono; 10th Feb 2013 at 15:27.
NTSC DVD always has 720x480 frame dimensions, a 3:2 frame aspect ratio. (704x480, 352x480, and 352x240 are also legal but I've never seen a commercial DVD with those sizes.) There is a flag that tells the player whether the video should be displayed with either a 4:3 or 16:9 display aspect ratio. If you keep the frame height at 480 pixels then that corresponds to a 640x480 or 853x480 frame. Of course, a display is free to resize to any frame size that matches the display aspect ratio (for example, 1920x1080 for 16:9 DAR). The DVD spec refers to the MPEG 2 spec regarding aspect ratios. The MPEG 2 spec says the full 720x480 frame comprises the display aspect ratio.
This is at odds with the ITU 601 spec for digital video capture (used by the TV industry) which says the 4:3 or 16:9 image is contained in a 704x480 frame. A larger 720x480 frame is often captured in case the signal is broadcast or captured a little off center. But the 4:3 or 16:9 DAR image still contained in a 704x480 sub-set of that frame.
This has led to some confusion about whether the same should be done with DVD. Ie, is the 4:3 or 16:9 picture contained in a 704x480 sub frame or the entire 720x480 frame (as the MPEG 2 spec states)? If you look at commercial DVDs some appear to follow the MPEG 2 spec, some the ITU spec. TV shows originating on video tape usually follow the ITU spec. Ie, they use standard studio digitizing equipment and capture 704x480 with padding to 720x480, and write to DVD without rescaling the inner 704 pixel width to 720. If you look at what commercial DVD players do, most appear to follow the ITU spec when putting out analog video (composite, s-video), the MPEG 2 spec when putting out digital video (HDMI).
If you assume the inner 704x480 contains the 16:9 image, then the full 720x480 frame holds a picture slightly wider than 16:9 -- by a ratio of 720/704. That corresponds to a width or ~872 pixels when using a vertical size of 480.
Last edited by jagabo; 10th Feb 2013 at 18:58.
I've not played with StaxRip much and I've never encoded a video using it. I think sometimes a person's brain must work the same way as the brain of the software author and the software seems to work as you'd expect it to, but StaxRip and myself didn't seem to get along. It's not so much that I didn't understand why it did something.... it was more having to work out what it was doing first in order to understand why.... but maybe I just didn't put enough time into that particular relationship to make it work.
Keep in mind, if you crop any of the video (ie black bars) then what you're left with (which I guess you could refer to as the actual picture area) must have a different aspect ratio than the uncropped version. If it didn't, it'd mean the remaining picture has been stretched to fill the area where the black bars once were, so virtually every DVD you encode will have a slightly different aspect ratio to the next. Assuming of course you don't deliberately crop the picture do have the same aspect ratio you started with. I do sometimes if it only means cropping a few extra pixels. And StaxRip does seem to crop fairly enthusiastically. It's a little hard to tell from your screenshot just what was done there.
By default, StaxRip seems to crop and resize to mod16 (width and height divisible by 16) and most of it's settings relating to how it crops and resizes etc aren't "global" settings as such, they're "project settings". Which is probably a good idea once you realise that's how it works, but I think it means if you change any of those options and encode a video, when you open the next one for encoding you need to save the "project" to use those same settings again. Or something like that.....
I suspect.... although I never took the time to work it out, that StaxRip actually does a good job of resizing without distorting the picture, but I guess the day I gave it a test run I wasn't in an arguing with software mood so I gave up too quickly. Anyway, I did have a little bit more of a play with it and I guess if we're going to get along I'll need to spend some more quality time with it as I've still not quite got my head around the way it's cropping methods and resizing work together, and I really don't understand why by default StaxRip always seems to crop 8 pixels from all four sides of the video whether it needs to or not. I gather it wouldn't be too hard to tell it not to, I'm just not sure why it does that in the first place.
I think that Staxrip is a great video converter. I don't crop, but instead I try to keep the original SAR, PAR and DAR as on the DVD when I'm converting to mp4. Then the size (aspect ratio) will be exact the same as on the DVD. Anamorphic.
By doing this you don't have to think about things like mod16, since the original SAR (in my case 720:576) will always be mod16.
I wasn't applying any cropping either, but am still getting this issue. Am I missing something?
Also, thank you to everyone that has responded, you have been more than kind!
According to my aspect ratio calculator, an NTSC DVD resized using the official ITU resizing method will display as 874x480. Using straight 16:9 resizing it'll display as 853x480. All software players I know of use the straight 16:9 (or 4:3) resizing method for displaying DVD video. It would appear StaxRip uses ITU resizing by default.
The setting to disable ITU resizing in StaxRip is under Options/Aspect ratio. To make it "stick" you might have to save any changes as a new project, or preset, or something..... otherwise next time you open a video using the same project template it'll revert back to the original settings..... ah yes.... that'd be the StaxRip terminology. I think you need to save the changes as a project template, and if memory serves me correctly you need to do that before opening a video. At least that's how I think it works.... I've never converted anything with StaxRip because we don't seem to get along but I have played with it a little.
Anyway.... disabling ITU resizing should get your encodes displaying the same as the original DVD in VLC if you're not cropping. DVDs can use either resizing method, although in my humble opinion, the majority don't use ITU resizing. There's no way to tell for sure aside from what looks correct to you. Or one method is to find a straight-on shot of something which should be round.... a clock face or a car wheel or a dartboard or something..... to see which resizing method makes it look the closest to being round..... but personally I think life's too short. I just use non-ITU resizing when encoding.
Then the DAR value under the resolution (720x480) should also change to 1.78. And the SAR should be 3:2(1.5).
If you do this, then the picture should be equal to the original.