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Old 17th April 2017, 05:18   #1  |  Link
Logan9778
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Any way to tell what --sar to use (ITU or non-ITU) for a DVD encode?

As the title.

I'm trying to encode one of my old Doctor Who dvd's to watch on plex, but I've realized, I don't know whether to tell X264 to use ITU or non-ITU SAR to get square pixels.

Is there ANY kind of program that can tell you whether it was recorded at ITU or non-ITU standards?

I'm using ITU for now, but its REALLY frustrating. It seems there would be a flag or such in the video. Or I guess they thought everyone would use a STANDARD like they should


Last edited by Logan9778; 17th April 2017 at 06:17.
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Old 17th April 2017, 06:17   #2  |  Link
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As the title.

Is there ANY kind of program that can tell you whether it was recorded at ITU or non-ITU standards?

No. Your eyes only.and/or the circle test.
Black left and right borders can be a hint for itu.
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Old 17th April 2017, 18:04   #3  |  Link
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Originally Posted by Sharc View Post
No. Your eyes only.and/or the circle test.
That is the true test - for there are movies that have been copied and/or edited under various conditions and media.
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Black left and right borders can be a hint for itu.
All my British (usually BBC) series have their margins matted, parts anyway hidden in a true analogue SDTV system. Probably all of them look like having been sourced from tapes, although people told me many of them have been filmed on film. Maybe "exported" series are low quality?
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Old 17th April 2017, 15:28   #4  |  Link
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The rule of thumb is if there's a reasonable amount of black down each side (8 pixels or more) it's probably ITU (after the black is removed what's left should be around 4:3), otherwise if the picture goes right to the edge of the frame it probably isn't ITU. There's no rule though. For sources that were originally video tape such as classic Doctor Who, the chances of them being ITU are probably quite high.

Personally instead of ITU SARs, I use the mpeg4 SARs. They're very close to the same as ITU, they're mpeg4 compliant, easier to remember, and it turns out it doesn't matter if a 4:3 DVD is PAL or NTSC, the display aspect ratio is exactly the same (15/11 or 1.363637). The same applies to 16:9 DVDs. There's only one mpeg4 display aspect ratio for both PAL and NTSC (20/11 or 1.818182), assuming you're not cropping, or course.

A list of PARs/SARs:
https://forum.doom9.org/showthread.p...27#post1058927

If you happen to be using MeGUI you can add 15/11 and 20/11 as custom Input DARs in the Script Creator.

Last edited by hello_hello; 17th April 2017 at 15:31.
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Old 17th April 2017, 15:40   #5  |  Link
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Quote:
Originally Posted by Logan9778 View Post
As the title.

I'm trying to encode one of my old Doctor Who dvd's to watch on plex, but I've realized, I don't know whether to tell X264 to use ITU or non-ITU SAR to get square pixels.
Instead of generating new AVC encodes, why not simply re-mux the DVD's MPEG-2 video (and audio) stream(s) into the .mkv container
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Old 17th April 2017, 18:27   #6  |  Link
Logan9778
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Thanks Guys! I always learn more and more everytime I come here!

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No. Your eyes only.and/or the circle test.
Black left and right borders can be a hint for itu.
Yeah, I forgot about borders. Hmm. It looks like they took a pic of the whole frame, out to the ragged edges, plus about 8 pixels left and right of the black stock.

Here's a pic from one of the VOB's.

https://picload.org/image/rcodgcla/v...2h43m04s13.png

What do you guys think?

Quote:
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Personally instead of ITU SARs, I use the mpeg4 SARs.
Ah, I thought I was using ITU, but it appears I'm already using the MPEG4 SARs. I've been using 12/11 for the PAL Doctor Who DVD's I have. Thanks!

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Instead of generating new AVC encodes, why not simply re-mux the DVD's MPEG-2 video (and audio) stream(s) into the .mkv container
I used to, but I REALLY HATE interlacing. That's why I started trying to learn AVISynth and its filters. I've found QTGMC running with AVISynth MT @ Placebo really cleans up the old Doctor Who video and does an excellent job of deinterlacing it. Encodes always look better than the original video. It appears it does a very light de-noise, which is nice, getting rid of some of the blotches, but leaving a lot of the grain. Plus, I can bob it, getting 50 FPS out of the video, which makes it smoother.

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Originally Posted by Ghitulescu View Post
Maybe "exported" series are low quality?
American NTSC recodes are the worst. We seem to get everything as a redone second thought.

Last edited by Logan9778; 17th April 2017 at 18:51.
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Old 17th April 2017, 19:11   #7  |  Link
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Here's a pic from one of the VOB's.

https://picload.org/image/rcodgcla/v...2h43m04s13.png

What do you guys think?
This picture is already expanded horizontally by the player to 768x576 overall (forced DAR 4:3), it seems. You should post it without any resizing applied.
My best guess is that on the DVD it is 720x576 including the borders with ITU PAR of 1150:1053 (approx. 12:11).
However, what irritates me is the small bottom border, but unfortunately any top border is not visible in your picture.
If there is a top border as well it could mean a Generic PAR of 16:15 with a bit of zooming in and perhaps slight cropping ....

No pictures with a nice circle ?

Last edited by Sharc; 17th April 2017 at 19:37.
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Old 17th April 2017, 19:26   #8  |  Link
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Quote:
Originally Posted by Logan9778 View Post
I used to, but I REALLY HATE interlacing.
What playback devices are you using? If the MPEG-2 stream has been correctly flagged your playback device should be able to correctly 'de-interlace' the displayed images.

If you're able to. Please upload a few seconds of one of your sources?
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Last edited by SeeMoreDigital; 17th April 2017 at 19:29.
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Old 18th April 2017, 00:13   #9  |  Link
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@ Sharc - I redid the shots with DGIndexNV straight from some VOBs. I don't think these are stretched in any way. Should be 720x576.

Working with the video, there does always appear to be a pixel or 2 of black on top and bottom, which I usually crop out when encoding video.

In one of them, shot 5 I think, I can see the bottom of the frame coming up. Looks like there's some slight movement of the frame around. Happens to move at the sides as well, as the crop fails to keep out the black at times due to shifting frame.

Tried to get some good circles in them. Shot 8 is a pic of DGIndexNV info panel.

https://picload.org/image/rcodcirr/shot1.png

https://picload.org/image/rcodcira/shot8.png

https://picload.org/image/rcodcirl/shot6.png

https://picload.org/image/rcodciri/shot5.png

https://picload.org/image/rcodcidr/shot4.png

https://picload.org/image/rcodcidl/shot3.png

https://picload.org/image/rcodcidi/shot2.png

@SeeMoreDigital - I use Zoom Player, VLC, and MPC-HD. Eventually, I plan on putting these on Plex. One of the reasons I do QTGMC is that I also then use Simple X264 to crunch down the video to about half the file size, using CRF 18 and Very Slow setting.

Here's a minute of video from Planet of the Giants DVD. Converted to x264, but it should all be original VOB dimensions, 720x576, etc.


https://mega.nz/#!V6xkQCjb!WSWUsDp_8...LUvXn6E6gJ2QVo

Last edited by Logan9778; 18th April 2017 at 00:57.
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Old 18th April 2017, 02:25   #10  |  Link
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Originally Posted by Logan9778 View Post
In one of them, shot 5 I think, I can see the bottom of the frame coming up. Looks like there's some slight movement of the frame around. Happens to move at the sides as well, as the crop fails to keep out the black at times due to shifting frame.
My personal cropping OCD forces me to stick to a few rules. One being I always crop for an exact 4:3 aspect ratio, or wider sometimes, but usually exactly 4:3. Never narrower than 4:3.

That means I invariably crop a bit of picture too, which helps ensure all the black is removed, except for the occasional DVD where the size of the borders changes dramatically. Then I'd use different cropping for different sections of the video.

I'd have to crop and resize your sample like so (assuming an mpeg4 Input SAR 12/11):

Crop(14, 4, -12, -4).Spline36Resize(640,480)

or some other 4:3 dimensions if resizing to square pixels. I'd bet a large amount of money there's no picture detail to be gained by resizing to a higher resolution than 640x480 though, given the source is interlaced.

The aspect ratio resulting from the cropping should technically be 1.3329, so there's a very tiny, almost unavoidable aspect error when resizing, but due to my personal 4:3 OCD, if not resizing I'd fudge the SAR just a little so the output DAR is still exactly 4:3. Instead of using 12/11 I'd go with SAR=1136/1041 and the output DAR should be 4:3. Damn OCD!

694 * 1136 / 1041 / 568 = 1.333333333333333333

Last edited by hello_hello; 18th April 2017 at 02:38.
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Old 18th April 2017, 09:01   #11  |  Link
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Here's a minute of video from Planet of the Giants DVD. Converted to x264, but it should all be original VOB dimensions, 720x576, etc.
It really needs to be a segment cut from your MPEG-2 DVD source
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Old 18th April 2017, 03:55   #12  |  Link
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Lol, interesting. I might try something like that one day. Sure would solve some display problems. But yeah, there would have to be a LOT of different cropping for these old DW DVDs. The film seems to barely shift many times.

I'm pretty sure now that the --sar should be 12/11. I finally found a good circle facing me that I was happy with, then did some comparison shots with the un-stretched VOB, the Make MKV output @ 4:3 forced and the final X264 product at 4:3 forced. Have to force or otherwise it tries to calculate a display ratio of 704:574.

Circle looks pretty good.

https://picload.org/view/rcodiigl/dr...t1211.png.html

And again, Thank you guys SO MUCH for your help!

Edit: Hmm, i did a test outputing a clip at --sar 12:11 and a clip at --sar:16:15. Forcing 4:3 AR on both videos, I couldn't tell the difference between them.

12:11 clip https://mega.nz/#!8jpQ0AIC!hRaqtP9iG...DxfC5Ri_T_z3-Y

16:15 clip https://mega.nz/#!AnZnzbIS!7OC0aKFCn...Inrt0Uz7VFY8s8

Last edited by Logan9778; 18th April 2017 at 05:52.
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Old 18th April 2017, 07:06   #13  |  Link
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Edit: Hmm, i did a test outputing a clip at --sar 12:11 and a clip at --sar:16:15. Forcing 4:3 AR on both videos, I couldn't tell the difference between them.[/url]
That's to be expected if they were cropped the same. They were encoded at the same resolution (704x572). The only difference is how they're stretched on playback due to the difference in pixel aspect ratio (SAR), but if you force the same display aspect ratio on playback, then they will be the same.

Personally I'm not timid about the cropping. If eight pixels need cropping for much of the video on one side, but for a few sections it's 12 or 14 pixels, I'd just crop 12 or 14 from the lot. The extra picture would have been off the edge of the screen back in the CRT days due to over-scanning so you wouldn't have seen it anyway. It's only if the cropping varies by a lot more than that I start getting fussy about it.

Cropping sections differently isn't hard to do if you know the frame numbers of the sections you want to change. For example if you wanted to change the cropping for frames 50 to 100:

Trim(0,49).Crop(14, 4, -12, -4)\
++Trim(50,100).Crop(2, 2, -24, -6)\
++Trim(101,0).Crop(14, 4, -12, -4)

As long as each section is cropped to the same resolution, or if you're resizing, as long as each section is resized to the same resolution etc.
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Old 18th April 2017, 09:10   #14  |  Link
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Edit: Hmm, i did a test outputing a clip at --sar 12:11 and a clip at --sar:16:15. Forcing 4:3 AR on both videos, I couldn't tell the difference between them.
Of course you couldn't. When you force the playback to 4:3 the player ignores the pixel aspect ratio (--sar or PAR) and stretches the picture including any borders stubbornly to 4:3 (or 16:9). That is what standalone players usually do with DVD or Blu-ray discs. There exists only 4:3 or 16:9 for playback, nothing else. SW players like MPC-HC for example offer the choice between fixed DAR (4:3, 16:9 ....) playback or playback according the Pixel Aspect Ratio (--sar or PAR) signalling which is read from the header of the video stream or from the container. (Unfortunately the info in the stream header and container are even sometimes conflicting for poorly authored material).

At the end, the difference between ITU and "Generic" (non-ITU) pixel aspect ratio is 2.4% only, and the "uneducated" viewer will most probably never complain about the slight distortion when the wrong pixel aspect ratio has been picked. Even more so considering the fact that ITU-DVDs with left/right borders are typically played slightly (2.4%) too narrow (forced 4:3 or 16:9 including borders) on todays HDMI digital player+TV infrastructure anyway. Hence no reason for sleepless nights

Last edited by Sharc; 18th April 2017 at 10:16.
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Old 18th April 2017, 19:29   #15  |  Link
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Yeah, thanks. Oh, my aching head I need to study AR again. But, it's probably going to force 4:3 on something like Plex anyway, isn't it? MPC-HC always reports PAR for 704x572 no matter what I force, so I can't tell what its doing. Zoom Player tells me forced 4:3 is 1.333 of course, and when I set it to source, I get 1.343 which is rounded AR for 704x572. So its taking the top and bottom crop into consideration as well. Should it be doing that?

But the worse part is, I don't think the aspect ratio is correct in any of the DW shows itself! There are NO round circles! Everything seems to be distorted! Doesn't matter if its VOB, MPEG pulled out with Make MKV, or the X264 encode. It's all the same as far as I can tell. Except for the ONE circle on the Dalek I found.

I need to find a new DVD where the circles are really round to test on.
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Old 18th April 2017, 20:03   #16  |  Link
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Now you are confusing me....
On DVD the objects are always distorted. I haven't seen a DVD with square pixels. It is always the player which cares for a undistorted playback, either by playing it as 4:3 or 16:9, OR according to the Pixel Aspect Ratio of the video stream.

Please upload a few seconds of the original .vob.

Last edited by Sharc; 18th April 2017 at 20:08.
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Old 18th April 2017, 21:57   #17  |  Link
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...It is always the player which cares for a undistorted playback, either by playing it as 4:3 or 16:9, OR according to the Pixel Aspect Ratio of the video stream.
Indeed
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Old 19th April 2017, 04:35   #18  |  Link
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Yeah, thanks. Oh, my aching head I need to study AR again. But, it's probably going to force 4:3 on something like Plex anyway, isn't it? MPC-HC always reports PAR for 704x572 no matter what I force, so I can't tell what its doing.
704x572 is the resolution or storage aspect ratio, not the picture/display aspect ratio.

Because expressing aspect ratios as the shape of the pixels isn't very intuitive, MPC-HC converts it to a display aspect ratio.



704x572 (192:143)

192 / 143 = 1.343
or
572 * 192 / 143 = 768
768 / 572 = 1.343

Admittedly that's not always particularly intuitive either, but it'd make less sense if MPC-HC displayed 16:15 or 12:11 as the aspect ratio for a 4:3 video.

Sometimes the aspect ratio shown next to "Video Size" is different to the aspect ratio listed in the video stream. That's because the video stream aspect ratio mightn't result in the video being resized to whole pixel dimensions, so the "Video Size" aspect ratio is rounded to whole pixels.

Last edited by hello_hello; 19th April 2017 at 04:43.
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Old 19th April 2017, 02:53   #19  |  Link
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What I mean is, some of the circles still look distorted at 1.333 (forced 4:3) or at 1.343 (12:11 PAR). It's weird. I downloaded Mpeg2cut2 that will cut and pull out clips of the Mpeg2 stream from the .vob so I will upload some clips from it.

https://mega.nz/#!BzQ0mIaB!Hynp1jvLE...4GdY2E7qPKbOUo

https://mega.nz/#!wrJwgJqR!A2xHEBrlY...xPjS4ImmbxIE0M

On the first clip, notice the black circle with the white X. It looks pretty off at 12:11 or forced 4:3.

On the second clip, the bottom dial looks distorted as does the circles on the elevators floor indicator. The decending lift doesn't look quite circular.

Mpeg2cut2 had some interesting AR's to view the vob with, and I tried 1.5 in particular. This made some of the dials look more circular, and the elevator floor indicator. However, the lift looked completely off.

What do you guys think?

EDIT: Hmm, I'm trying Hello_Hello's "Crop(14, 4, -12, -4).Spline36Resize(640,480)" to see how it comes out.

Last edited by Logan9778; 19th April 2017 at 04:18.
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Old 19th April 2017, 16:40   #20  |  Link
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...I downloaded Mpeg2cut2 that will cut and pull out clips of the Mpeg2 stream from the .vob .....
Just for your info: you can extract a segment from a .vob with DGIndex as well. Simply select the range with the brackets [.......] and save.
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