DVD Video Resolution

[jay123210599]

I have a DVD video that is 720x480. But I used PotPlayer, MPV, or MPC-HC to take a screenshot from it, the resolution is 852/853x480? Which one is the true resolution for the video?

[huhn]

NTSC 720x480 and PAL 720x576 there are smaller ones no one cares about the screenshot function is working correctly in that case.

[RetsimLegin]

Looks like that video is Anamorphic aka enhanced for widescreen TVs etc. Meaning that when displayed (properly) it's displayed at 16x9 ratio. That's why a screen shot would appear wider than the actual source matrix. So there are 720x480 actual discrete pixels in the source but they are intended to be displayed not square.

[StainlessS]

Looks like that video is Anamorphic aka enhanced for widescreen TVs etc. Meaning that when displayed (properly) it's displayed at 16x9 ratio. That's why a screen shot would appear wider than the actual source matrix. So there are 720x840 actual discrete pixels in the source but they are intended to be displayed not square.
Typo ? [EDIT: ie 480]

[RetsimLegin]

Corrected thx.

[wonkey_monkey]

DVD video pixels aren't square. Whether it's anamorphic or not, the picture needs to scaled differently in each dimension to produce the correct aspect ratio to display on a square-pixel screen.

(players should, strictly speaking, also crop off 8 (NTSC) or 9 (PAL) pixels from each edge to account for nominal analogue blanking, but few bother, and a lot of DVDs are produced wrong in that regard anyway)

[jay123210599]

So 852/853x480 is the true resolution for my video? That's the correct one?

[GeoffreyA]

So 852/853x480 is the true resolution for my video? That's the correct one?

I think it's a matter of language. The "actual" resolution, as stored, is 720x480, but to be displayed correctly, it has to be stretched. One could think of that as the "true" resolution. Most important is that the aspect ratio, after cropping, is right.

[huhn]

no the resolution is 720x480. screenshoot can not be anamorphic so the video renderer has to correct that. the original resolution AR is not watchable on modern devices which are squared now.

there is also 4:3 with he exact same resolution.

[SeeMoreDigital]

So 852/853x480 is the true resolution for my video? That's the correct one?
720x480 pixels [for NTSC DVD's] or 720x576 pixels [for PAL DVD's] represents the number of pixels encoded [in MPEG-2] on a typical store bought disc.

In the case of NTSC DVD's an image pixel size of 853x480 for 16:9 shapes or 640x480 for 4:3 shapes represents the number of pixels displayed by the software or hardware player, which you can screenshot.

In the case of PAL DVD's an image pixel size of 1024x576 for 16:9 shapes or 768x576 for 4:3 shapes represents the number of pixels displayed by the software or hardware player, which you can screenshot.

[jay123210599]

720x480 pixels [for NTSC DVD's] or 720x576 pixels [for PAL DVD's] represents the number of pixels encoded [in MPEG-2] on a typical store bought disc.

In the case of NTSC DVD's an image pixel size of 853x480 for 16:9 shapes or 640x480 for 4:3 shapes represents the number of pixels displayed by the software or hardware player, which you can screenshot.

In the case of PAL DVD's an image pixel size of 1024x576 for 16:9 shapes or 768x576 for 4:3 shapes represents the number of pixels displayed by the software or hardware player, which you can screenshot.

so is that a yes or a no?

[huhn]

the true resolution of the video is 720x480. the end.

[Z2697]

It's 720x480 but the pixels are not square LOL (insert galaxy brain meme) (ah, the old days that are no more)

For the sake of correct aspect ratio on modern display it has to be scaled.
But which (the "original" or "scaled" resolution) is more "appropriate" depends on certain scenario.

Now as far as I'm concerned, Jay will still ask for "yes or no".
(Jay the interrogator?)

[Sharc]

the true resolution of the video is 720x480. the end.
A matter of definition what we understand by "true" resolution. One may for example upscale and pack a lower resolution video of say 380x240 into a frame size of 720x480 pixels, but the "true" resolution (in terms of picture details) is still not better than the original 380x240.

[SeeMoreDigital]

the true resolution of the video is 720x480. the end.A matter of definition what we understand by "true" resolution...On an store-bought DVD the MPEG-2 video stream on an NTSC DVD is encoded with 720x480 pixels and on an PAL DVD it's encoded with 720x576 pixels... There can be no argument, that's it...

[wonkey_monkey]

On an store-bought DVD the MPEG-2 video stream on an NTSC DVD is encoded with 720x480 pixels and on an PAL DVD it's encoded with 720x576 pixels... There can be no argument, that's it...

Err... there can be an argument, sorry, because widths of 704 and 352 are also within spec for DVD :D I think half heights are also valid.

Granted they'll be rare, but there are definitely at least some 704xHHH DVDs out there.

[Z2697]

On an store-bought DVD the MPEG-2 video stream on an NTSC DVD is encoded with 720x480 pixels and on an PAL DVD it's encoded with 720x576 pixels... There can be no argument, that's it...

What he meant is like, imagine a 2.4:1 movie in bluray, the "true" resolution of the actual content is 1920x800, while the "true" resolution of video stream is 1920x1080.

Which one is "true", or the way I prefer to think it, which one is more appropriate, it all depends.
What are you gonna do with that number? Cropping? Displaying? Scaling? Something else?

For example, if someone is gonna "enhance" the 16:9 NTSC DVD with "AI", the more appropriate one is the scaled one (imo), because if you are gonna upscale it anyway, better just do the aspect ratio correction together with it, "AI" upscale it then reduce the height, or maybe stretch it horizontally then "AI" upscale, if that increases the accuracy of "AI".


Simply speaking:
DEFINE TRUE :cool:
A clear and widely accepted definition of "true" is helpful.

[huhn]

there is even more no time to care about it: https://en.wikipedia.org/wiki/DVD-Video

if the 704 is with and without the over scan pixel doesn't matter here so yeah.

[huhn]

What he meant is like, imagine a 2.4:1 movie in bluray, the "true" resolution of the actual content is 1920x800, while the "true" resolution of video stream is 1920x1080.

Which one is "true", or the way I prefer to think it, which one is more appropriate, it all depends.
What are you gonna do with that number? Cropping? Displaying? Scaling? Something else?

For example, if someone is gonna "enhance" the 16:9 NTSC DVD with "AI", the more appropriate one is the scaled one (imo), because if you are gonna upscale it anyway, better just do the aspect ratio correction together with it, "AI" upscale it then reduce the height, or maybe stretch it horizontally then "AI" upscale, if that increases the accuracy of "AI".

the video in this case is 1920x1080. the end.

that's the resolution if used or it.

[GeoffreyA]

The video is in a superposition of both 853x480 and 720x480, and depending on the collapse of the wave function, it goes either way :)

Well, instead of "true" resolution, it might be better to use terms like "stored" or "display" resolution. I think the controversy here springs from applying a high-level concept, "true," to an implementation detail.

[SeeMoreDigital]

Well, instead of "true" resolution, it might be better to use terms like "stored" or "display" resolution...Personally I prefer the term 'encoded' resolution rather than stored resolution ;)

[huhn]

The video is in a superposition of both 853x480 and 720x480, and depending on the collapse of the wave function, it goes either way :)

Well, instead of "true" resolution, it might be better to use terms like "stored" or "display" resolution. I think the controversy here springs from applying a high-level concept, "true," to an implementation detail.

the resolution of the video is just the resolution of the video. nothing more nothing less. it's 720x480. the screenshoot function could have done 720x405 too but that does not change the video resolution.

a default 16/9 broadcast1440x1080i stream has a resolution of up to 1440x1080 and nothing over that.

[jay123210599]

If the true resolution is 720x480, how do I get my video players to take screenshots of that resolution instead of 852/523x480?

[huhn]

they can do that there is no general answer. but these screenshots are worthless.

[FranceBB]

If the true resolution is 720x480, how do I get my video players to take screenshots of that resolution instead of 852/523x480?

The player is correctly reading the flag and resizing, then it takes the screenshot. Leave it alone, but if you *must* take the screenshot of the anamorphic content without reading the flag and without the resizing being applied, just index it with either FFVideoSource() or LWLibavVideoSource() in Avisynth and take the screenshot out of that by going to the desired point, right clicking on the image in AVSPmod mod and saving the PNG or JPEG or TIFF or whatever. Again, I'd suggest you not to do that unless you wanna show people a particular artifact for some reason and you therefore need the non deinterlaced and not resized anamorphic sample. For any other use case, trust the players, they're literally meant to read the aspect ratio flag and resize accordingly (you can check the flag yourself in Mediainfo to see whether it's set to 4:3 or 16:9).

[jay123210599]

The player is correctly reading the flag and resizing, then it takes the screenshot. Leave it alone, but if you *must* take the screenshot of the anamorphic content without reading the flag and without the resizing being applied, just index it with either FFVideoSource() or LWLibavVideoSource() in Avisynth and take the screenshot out of that by going to the desired point, right clicking on the image in AVSPmod mod and saving the PNG or JPEG or TIFF or whatever. Again, I'd suggest you not to do that unless you wanna show people a particular artifact for some reason and you therefore need the non deinterlaced and not resized anamorphic sample. For any other use case, trust the players, they're literally meant to read the aspect ratio flag and resize accordingly (you can check the flag yourself in Mediainfo to see whether it's set to 4:3 or 16:9).

Here's the info for my video:

ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L3
Format settings : CABAC / 6 Ref Frames
Format settings, CABAC : Yes
Format settings, Reference frames : 6 frames
Codec ID : V_MPEG4/ISO/AVC
Duration : 23 min 43 s
Bit rate : 1 803 kb/s
Nominal bit rate : 2 246 kb/s
Width : 720 pixels
Height : 480 pixels
Display aspect ratio : 16:9
Original display aspect ratio : 3:2
Frame rate mode : Variable
Frame rate : 24.052 FPS
Original frame rate : 29.970 (30000/1001) FPS
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.217
Stream size : 306 MiB (90%)
Writing library : x264 core 120 r2164 da19765
Encoding settings : cabac=1 / ref=6 / deblock=1:1:1 / analyse=0x3:0x133 / me=umh / subme=7 / psy=1 / psy_rd=0.40:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=1 / 8x8dct=1 / cqm=2 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=1 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=5 / b_pyramid=0 / b_adapt=1 / b_bias=0 / direct=3 / weightb=1 / open_gop=0 / weightp=2 / keyint=300 / keyint_min=29 / scenecut=40 / intra_refresh=0 / rc_lookahead=40 / rc=2pass / mbtree=1 / bitrate=2246 / ratetol=1.0 / qcomp=0.60 / qpmin=10 / qpmax=51 / qpstep=4 / cplxblur=20.0 / qblur=0.5 / ip_ratio=1.40 / aq=1:0.60
Default : Yes
Forced : No

[Sharc]

It's just unfortunate that frame dimensions (aka frame size) expressed in pixels width x height are exchangeably used and mixed with "resolution" or "true resolution" etc.
Remember the discussions about the "true resolution" of some Blu-ray releases with frame dimensions of 1920x1080 pixels being just upscaled DVDs with a notably disappointing visual (or "true", "effective", "lower than 1920x1080" - however we name it...) resolution. Frame dimensions used as snake oil for "resolution" of the content (video).:devil:

[SeeMoreDigital]

Here's the info for my video:

ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L3
Format settings : CABAC / 6 Ref Frames
Format settings, CABAC : Yes
Format settings, Reference frames : 6 frames
Codec ID : V_MPEG4/ISO/AVC
Duration : 23 min 43 s
Bit rate : 1 803 kb/s
Nominal bit rate : 2 246 kb/s
Width : 720 pixels
Height : 480 pixels
Display aspect ratio : 16:9
Original display aspect ratio : 3:2
Frame rate mode : Variable
Frame rate : 24.052 FPS
Original frame rate : 29.970 (30000/1001) FPS
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.217
Stream size : 306 MiB (90%)
Writing library : x264 core 120 r2164 da19765
Encoding settings : cabac=1 / ref=6 / deblock=1:1:1 /.................
Default : Yes
Forced : No

Well... that's not an 'store bought' MPEG-2 DVD source...

[GeoffreyA]

It's just unfortunate that frame dimensions (aka frame size) expressed in pixels width x height are exchangeably used and mixed with "resolution" or "true resolution" etc.
Remember the discussions about the "true resolution" of some Blu-ray releases with frame dimensions of 1920x1080 pixels being just upscaled DVDs with a notably disappointing visual (or "true", "effective", "lower than 1920x1080" - however we name it...) resolution. Frame dimensions used as snake oil for "resolution" of the content (video).:devil:

And it's continuing into the 4K era.

[RetsimLegin]

To understand this (hopefully) you need only look at this part of your MediaInfo:

Width : 720 pixels
Height : 480 pixels
Display aspect ratio : 16:9

The 720x480 indicates what was encoded/stored in the file. The DAR instructs the playback equipment how to properly display it. In a different file that DAR may read 4x3 in which case the display would show those 720x480 pixels differently.

[tebasuna51]

I have a DVD video that is 720x480. But I used PotPlayer, MPV, or MPC-HC to take a screenshot from it, the resolution is 852/853x480? Which one is the true resolution for the video?

Codec ID : V_MPEG4/ISO/AVC
Writing library : x264 core 120 r2164 da19765
You not have a DVD video, must be H.262/MPEG-2 Part 2, seems you have a source DVD recoded to h264 video

Width : 720 pixels
Height : 480 pixels
Display aspect ratio : 16:9
Seems it is correctly recoded preserving the original anamorphic (not square pixels) video resolution and the Display aspect ratio needed to convert to square pixels screens.

A correct player must display it to 853x480 in window mode or in full sreen mode to 1280x720, 1920x1080, etc. depending of screen resolution.

Frame rate mode : Variable
Frame rate : 24.052 FPS
Original frame rate : 29.970 (30000/1001) FPS
Scan type : Progressive

Here maybe there are a problem, a DVD NTSC must be always (30000/1001) FPS interlaced (also can be progressive) then must be deinterlaced (normally) to 24000/1001=23.976... Progressive and not 24.052, the variable Frame rate can be a problem or a audio async.

Also don't exist colour space info. The standard for DVD is REC 601, for h264 is REC 709, we don't know if was converted.

[jay123210599]

they can do that there is no general answer. but these screenshots are worthless.

Which resolution of the screenshots would be worthless?

[huhn]

720x480 that's not how it should be watched.

[RetsimLegin]

They say a picture (or two) is worth a thousand words. In fact I had to fake this from another source but it illustrates.

This is a screenshot at 853x480 taken from a 16x9 movie
https://drive.google.com/file/d/15k_PF_fvp5xawxIntkB1DotkhjBfSaeo/view?usp=sharing
Let's suppose the source file for that was 720x480 and the display had (properly) resized it. If I looked at that source natively, it would look like this
https://drive.google.com/file/d/1UqUbd4XuJXZeszt_cDA24RV6qpKOJqLc/view?usp=sharing

You should clearly notice that the shape of the lady's face in the second shot is distorted; is too tall for its width. That is why a pixel-accurate screenshot is (sort of) worthless - or at the very least, inaccurate. The image was never intended to be seen distorted like this.

[SeeMoreDigital]

720x480 that's not how it should be watched.Indeed, it needs either 4:3 or 16:9 DAR applied.