Why is Plex identifying SD video as 576p?

General Discussions
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@leelynds said:
Now everything transcodes, so it just doesn’t matter. I’ve seen a few posts around the forums suggesting that more things are transcoding recently, to various clients that used to direct play. Coincidentally, resolution labels changed about the same time.

It would be scary if Plex used as a source for information to decide whether to transcode or not data from a label that plex developers themselves admitted they don’t really understand :open_mouth:

Limiting the resolutions to UHD, HD, and SD won’t make me happy, Neither would suggestions that all videos ripped from DVD without an anamorphic setting and a 720X480 or 720X576 resolution be considered SD because they were encoded wrong.

I agree. They should be called 576p or 480p if they retain the same display resolution of the original material, which can be obtained in many different ways

No one is ever gonna convince me that I am clueless because I don’t use anamorphic settings, and no one is gonna convince me that the cropped to 1280X544 video in the other thread was not ripped properly.

To use anamorphic or not is a matter of method and personal preference, cropping black bars from 720p and 1080p material is just reasonable, I don’t see how that could be considered “wrong”

Regardless, in all cases, anamorphic or not, cropped or not, Plex used to report an expected result.

Ah the good old times…

Sure, there were exceptions… Handbrake by default resizes a 4:3 aspect DVD to 720 X 540 (NTSC or PAL) and we got a 576p label. It also, by default, resizes a 16:9 DVD to 720 X 404 (NTSC or PAL) and plex gave us an SD label. Guess what? I agree with those labels.

Me too! for 4:3 material the difference between PAL 720x540 and 768x576 (expanded 4:3 with square pixels) or anamorphic expanded 720x576 is really negligible, on the other hand there’s a noticeable difference between a 720x576 16:9 (or 1024x576) and a 720x404, and the SD label was completely acceptable to distinguish between the two.

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@zpaolo11x said:
The box suggestion is good but the box escalation can be tricky: let’s say you have a 16:9 anamorphic DVD with a 2.35 movie, you strip the black bars and you encode a 720x436 anamorphic 2.35:1 stream. This stream has the exact same resolution and view quality of the 576p DVD it was taken from, but will perfectly fit in a 480p box.

I understand the problem with anamorphic rips, particularly when they have been cropped and keep the original pixel aspect ratio. Yes, using my suggestion of the 16X9 box, your PAL DVD would be labeled as 480p. My NTSC rip of the same video using the same method would end up at 720X338 (if my calculations are correct) It would be labeled as SD.

I guess my point is, since the original anamorphic source has been cropped vertically we have to accept the final resolution. I think the difference between PAL and NTSC vertical resolutions and the effort to recognize cropped PAL videos as 576p got us to this point. Unfortunately, we ended up with more 576p videos than we should have. :slight_smile:

Cropped, anamorphic rips are the exception to the rule, because they are going to have a width of (usually) 720. I guess you could have the encoding software force a 480 or 576 vertical resolution by “guesstimating” - that is, upscaling the remaining pixels to the desired resolution. I’ve never done that, but I imagine the anamorphic flag or pixel aspect would change from 16:9 to 2.35:1 so that it is displayed properly.

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@leelynds said:
I understand the problem with anamorphic rips, particularly when they have been cropped and keep the original pixel aspect ratio. Yes, using my suggestion of the 16X9 box, your PAL DVD would be labeled as 480p. My NTSC rip of the same video using the same method would end up at 720X338 (if my calculations are correct) It would be labeled as SD.

If my calculation are correct, the NTSC version should be 720x364 (we are talking of an anamorphic 16:9 NTSC DVD with 720x480 resolution and a 2.35:1 movie image)

I guess my point is, since the original anamorphic source has been cropped vertically we have to accept the final resolution.

I agree, but if the final definition is the same as the original then why not use the same label? I mean, if you crop the black bars from a 720p movie, you don’t want it called something else because, in the end, the information is still there. It’s the same if you crop the black bars from a 2.35:1 DVD in anamorphic 16:9 format: you are not depriving it from useful information.

I think the difference between PAL and NTSC vertical resolutions and the effort to recognize cropped PAL videos as 576p got us to this point.

Yes, together with the poor knowledge of such video formats from Plex. But the solution is still there and it is to take into account Display Aspect Ratio when evaluating. Because a movie with a 720x436 storage resolution and a display aspect ratio of 2.35:1 CAN ONLY BE a cropped 2.35 movie frame from a 720x576 16:9 anamorphic. If it was a 480p movie the display aspect ratio would be different. Same goes the other way: a 720x364 movie with 2.35 aspect ratio can’t be 576p, it’s obviously a 480p 16:9 anamorphic cropped to remove the black bars and retain the full information from the 2.35:1 frame.

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And you don’t even need the box: let’s not consider 4:3 material for a while, and let’s consider the widely popular case of encodings with black bars removing. There’s a magic formula that can help you:

VERTICAL STORAGE RESOLUTION * DISPLAY ASPECT RATIO = ?

If the result is 1024 then it’s 576p
If the result is 854 then it’s 480p
If the result is 1280 then it’s 720p
If the result is 1920 then it’s 1080p

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That might work for some, but there would have to be a “fudge” factor, of course. Remember, though, not all sources are DVD, BluRay, and Broadcast. And there are probably thousands of sizes people encode at, and right or wrong is totally irrelevant. But they still need a label somehow.

For example, I have a friend who hates the black bars on 2.35 movie. He would crop a 1280X544 video to 968X544 to get the full screen picture on his TV, and particularly for his smaller screened tablet. His preference, his right to do so, and he does that all the time. How do you label his video using the aspect ratio formula? Is it 480p or 576p or a new label of 544p?

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@leelynds said:
That might work for some, but there would have to be a “fudge” factor, of course. Remember, though, not all sources are DVD, BluRay, and Broadcast. And there are probably thousands of sizes people encode at, and right or wrong is totally irrelevant. But they still need a label somehow.

The fact that someone doesn’t follow standards should not impact those who apply to them. If you follow the standard or if your result is indistinguishable from the standard, then you get the 576p/480p/720p/1080p label. If you don’t follow the standard I honestly don’t care much. 720x404 16:9 can be called SD for example, weirder formats that don’t fit in any label… they don’t fit in any label so it’s up to Plex to define a “label for things that don’t fit”

For example, I have a friend who hates the black bars on 2.35 movie. He would crop a 1280X544 video to 968X544 to get the full screen picture on his TV, and particularly for his smaller screened tablet. His preference, his right to do so, and he does that all the time. How do you label his video using the aspect ratio formula? Is it 480p or 576p or a new label of 544p?

Oh my god my eyes started bleeding as soon as my mind realized what your friend is doing :smiley:

For this kind of stuff (lime my infamous “quarter1080p”) Plex should come out with a generic labeling like “SD” and “HD” that doesn’t use any specific labeling. That video is for sure not 720p, it’s actual definition will be more akin to the one of a 16:9 576p but still it will be a bit better. It’s HD, even if a bogus HD

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The problem is the “standards” thing. If we only accept “Standard” as the only true label, then only 1920X1080 are 1080p, 1280X720 are 720p, 720X576 are 576p and 720X480 are 480p.

You can’t apply standards hodge podge as you personally see fit. Your willing to let anything that doesn’t fit the DVD standards for NTSC or PAL get labeled as SD, but on the other hand you want the 1280X544 video to be labeled 720p. Clearly, 1280X544 doesn’t fit the 720p standard, it’s shy by about 176 pixels. So, if you can have 720p for that video that doesn’t meet any standard, why do I have to settle for “SD” for my 720X364 anamorphic video because it doesn’t meet the 480p standard?

See where I’m going here… because there are so may methods and sizes of video, (and yes, many are probably unusual) we can’t blindly apply a “Standard” as the definitive solution.

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@leelynds said:
The problem is the “standards” thing. If we only accept “Standard” as the only true label, then only 1920X1080 are 1080p, 1280X720 are 720p, 720X576 are 576p and 720X480 are 480p.

Let’s stop this standards vs non-standards game right here, right now. I clearly stated that with “standards” I mean when en encoding adheres strictly to the standard resolution of the label OR is black-bars-cropped/anamorphic-expanded so that the end result is the same, in terms of resolution, as the standard.

See where I’m going here… because there are so may methods and sizes of video, (and yes, many are probably unusual) we can’t blindly apply a “Standard” as the definitive solution.

No I don’t frankly understand your reasoning. There are not many resolutions and screen sizes that fits in the 576p/480p/720p/1080p label as defined above, it’s fairly easy to apply the label following the formula, and it’s fairly easy to discard all “custom” resolutions no ones really cares for, starting from the people who actually use them.

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And 720x364, if anamorphic 2.35:1, is 480p by my definition, not SD

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I wrote a quick function to test this out. I took some of the resolutions mentioned in this thread to test it. Would you guys agree with the label it would generate?
480x360=360
640x232=360
538x404=SD
720x304=SD
720x390=SD
720x480=480
720x480 anamorphic=480
720x576=576
720x576 anamorphic=576
1024x576=720
960x576=720
960x720=720
1280x464=720
1440x1080=1080
1920x696=1080
720x400=SD
720x400 anamorphic=480
688x288=SD
720x364=SD
720x364 anamorphic=480
720x576=576
720x576 anamorphic=576
854x480=720
720x576 anamorphic=576
720x554 anamorphic=576
720x404=SD
720x404 anamorphic=480
852x488=720
704x576=576
704x576 anamorphic=576
704x480=480
704x480 anamorphic=480
2880x2160=UHD
3840x1392=UHD
4096x2160=4K
6144x3240=8K
8192x4320=8K
6144x3240=8K
856x464=720
856x480=720
1024x576=720
1280x544=720
720x367=SD
720x367= anamorphic=480
1920x710=1080
720x404=SD
1024x576=720
1022x552=720
720x400=480

1 Like
231

@cayars said
I wrote a quick function to test this out. I took some of the resolutions mentioned in this thread to test it. Would you guys agree with the label it would generate?

Everything has an “A-OK” as far as I’m concerned. Of course, there’s a million video sizes not listed, but it looks like your formula will likely cover them. When I have a little more time, I’ll post some “odd” size videos I have, and maybe you can run them thru and report back. Yes, I create some un-standard size videos, and I’m not that ashamed at all B)

232

Sure thing, no problem trying a few other oddball sizes. BTW, I expanded the “4K” section a bit and used UHD label for stuff up to 3840x2160 then 4K for stuff up to 4096x2160. Beyond that gets the 8K which is a cover all for now.

2880x2160=UHD
3840x1392=UHD
4096x2160=4K
6144x3240=8K
8192x4320=8K
6144x3240=8K

So do you prefer UHD, 4K, 8K broken out like this or just lump them all into “4K” for now?

576i media being flagged as 480i or 576p *on different players*
233

I think the list is ok, did you use my formula? As leelynds said it’s difficult to account for “fancy” resolutions that don’t fit directly, but it’s a good start.

I developed a different formula that calculates the “screen area per storage pixel” which could be a way to define some “ranges” for SD and HD when nothing fits tightly in the definitions of 576p/480p/720p/1080p but maybe it’s a bit overkill :smiley:

234

No sorry, I don’t recall seeing a formula of yours anywhere in the thread for generating the different labels.

I think if you understand SAR, PAR & DAR it’s pretty clear how to calculate the labels.

Carlo

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@cayars said:
I think if you understand SAR, PAR & DAR it’s pretty clear how to calculate the labels.

I agree

236

Just wanted to report that with Plex Media Server 1.7.2 (PlexPass only) that all of my media is reporting resolutions where I expected them to be. Thanks for returning all of the 480p resolutions to my system to anyone and all involved in fixing it.

As to my original question, way back on page one of this thread,

My only concern is that since they are now being identified as 576p, will this new resolution force a transcode to users asking for 480p at 1.5 Mbps even though the bitrate is in that range

I haven’t had the opportunity to test a remote connection, but I can confirm that on local connections with the quality setting dropped down to 480p/1.5 mbps, that they are once again direct played, where they were transcoded with the previous labels (at least on Rokus)

A bigger thank you for eliminating the need for my server to transcode files that should have direct played.