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Old 9th December 2012, 15:22   #16101  |  Link
Qaq
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Originally Posted by madshi View Post
You mean you got problems with wrong colors with deinterlacing turned on?
Nope. I'm stick with XP now and have not tried DXVA2 things yet.
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Or what do you mean?
I mean that with 12 Catalyst you may find some postprocess feature disabled but its still working.
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And what does HDCP have to do with anything?
The main goal is to prevent HDCP encoded video stream from affecting by crapy video driver. Just like audio bitstream you know. I won't be suprised if I'm wrong here though.
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Old 9th December 2012, 15:49   #16102  |  Link
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Originally Posted by madshi View Post
Well, do the math yourself:

16/9 = ?
1024/576 = ?
1050/576 = ?
576 * 16 / 9 = ?

It's not a good idea to blindly trust some website if you can do the proper math yourself...
It's not quite as simple as that as you aren't considering the aspect ratio of the source...

Standard ITU 601 SD video is conventionally carried in a 720x576 frame. HOWEVER - this frame is slightly wider than 4:3 or 16:9. A 720x576 frame is NOT a 4:3 or 16:9 source. It's wider than 4:3 or 16:9. If you scale directly from a 720x576 ITU 601 source frame to 1024x576 (for 16:9) or 768x576 (for 4:3) square pixels ignoring this fact, then you're going to slightly stretch things...

In fact, for 50Hz video, the central 702x576 portion of the 720x576 frame contains the 4:3 or 16:9 image - with 9 samples either side to ensure no under/overshoots etc. are cropped. (Incidentally - this is why some DVB broadcasts are 704x576 - the nearest multiple to 702x576 compatible with MPEG2/H264 compression - rather than 720x576)

If you simply scale the 720x576 image to 1024x576 (16:9 square pixels) or 768x576 (4:3 square pixels) you're stretching the image slightly, and incorrectly...

If you want to scale 16:9 ITU 601 video to 1024x576 to create a 16:9 frame, then you need to scale the central 702x576 area to 1024x576 square pixels (NOT the 720x576 full frame).

However if you are working with pro-video systems, but need to work square pixels (say in compositing etc.) then you scale the 720x576 frame to 1050x576 square pixels, with the central 1024x576 portion containing the 16:9 frame. It's generally seen as bad practice to crop 720x576 video to 702x576 video during the production chain.

(If you leave the 18 samples outside the 702x576 frame - 26 samples outside the 1024x576 frame - black you can hit issues if you start shrinking pictures - as you'll see the black edges)

1050 x 576 is obviously wider than 16:9 - but explains where the 1050 vs 1024 figures come from.

It's surprising how many companies get this wrong. Adobe did initially... You still see annoying width changes in some broadcast chains where things are going wrong.

http://81-208-25-53.ip.fastwebnet.it...missioning.pdf

http://www.mikeafford.com/blog/2009/...ts-cs4-vs-cs3/

If you scale 720x576 video you either crop 9 samples either side and scale 702x576 to 1024x576, or you scale 720x576 to 1050x576 and then crop 13 samples either side from the 1050x576 frame to get 1024x576.

This all dates back to basics and the analogue TV systems SD digital TV standards are based on. In 576/50i analogue video (aka 625/50 analogue component or analogue composite PAL/SECAM) the active video occupies 52us of a 64us line. If you sample this active video at 13.5MHz (as ITU 601 does for luminance) you end up with 702 samples in 52us. That is 702 samples for a full width 4:3 or 16:9 image. ITU 601 padded this to 720x576 for multiple reasons. This is why a 4:3 or 16:9 ITU frame is contained within the central 702x576 section of a 720x576 ITU 601 frame. Otherwise you'd need to do all sorts of resampling/reclocking when converting between analogue and digital video.
In the late 70s/early 80s when ITU 601 was being ratified (as CCIR Rec 601) digital devices were islands in analogue installations, and needed to be as transparent as possible. As analogue signals are often not very 'clean' - it made a lot of sense to sample a little bit more than the 702x576 active video portion, to avoid cropping edge transients with harmonics etc. which if cropped could induce ringing, and also to cope with devices that had somewhat less-than-ideal line timing (like VTRs of that era). It's similar thinking to having 16-235 rather than 0-255 dynamic range in active video (so that you don't clip undershoots and overshoots which could easily be present on analogue sources)


(NB. I used to be a broadcast video R&D engineer and did a LOT of work with ITU 601 4:3 and 16:9 video back in the day...)

Last edited by Sneals2000; 9th December 2012 at 16:38.
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Old 9th December 2012, 16:06   #16103  |  Link
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Originally Posted by mandarinka View Post
This says 1050 576 (ITU scaling).
For 16:9 SD ITU 601 video :
720x576 scales to 1050x576 square pixels (i.e. the full 720x576 frame is wider than 16:9)
702x576 scales to 1024x576 square pixels (i.e. crop 9 samples from either side of the 720x576 frame to isolate the central 16:9 image area)

For 4:3 :
720x576 scales to 788x576 square pixels (i.e. the full 720x576 frame is wider than 4:3)
702x576 scales to 768x576 square pixels (i.e. crop 9 samples from either side of hte 720x576 frame to isolate the central 4:3 image area)

This is because 720x576 ITU 601 video is wider than 4:3 or 16:9 - the 4:3 or 16:9 portion is within the central 702x576 portion.

Something that a LOT of people get wrong...

If you are scaling 16:9 SD 576/50i video to 1920x1080 or 1280x720 square pixel 16:9 resolutions then you need to crop 9 samples either side from the 720x576 frame and scale the central 702x576 portion to 1920x1080 or 1280x720..

(I'm sure lots of people think the 702x576 used by people who really understand digital video - like broadcast engineers - is a typo for 720x576... It isn't.)

It may not seem important - but when you feed video through multiple up/down converters, and drop devices into and out of the broadcast chain, you definitely see things go wrong...

Last edited by Sneals2000; 9th December 2012 at 16:10.
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Old 9th December 2012, 16:32   #16104  |  Link
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I have to admit that I never quite understood the whole 720x576 being 4:3 AR with non-square pixels story...but hey, they make 1024x768 Plasma TV's with a 16/9 AR, so I assumed that non-square pixels were an acceptable practice in the video world.

So how do you know the actual AR of a 720x576 FS stream then? Are you saying that 720x576 FS is not/never meant to be watched with a 4:3 AR? It sure looked OK to me

Last edited by leeperry; 9th December 2012 at 17:51.
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Old 9th December 2012, 17:09   #16105  |  Link
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@Sneals2000,

thanks a lot for your informative post, this is the first time I hear of that. I do have a few worries, though. Would you mind to address them?

(1) Does this only apply to BBC / UK, or to all PAL content world wide?
(2) Does this also apply to PAL DVDs?
(3) How about NTSC? Any similar sheenigans going on there, too?

I'm especially wondering about PAL DVDs. Since DVDs are all digital, and most DVDs are being encoded directly from the 2K (or higher) masters, I'm wondering if DVD encoding houses encode AR to 720x576 or to 702x576?

Thanks!

Call for test: Anyone who has DVDs and Blu-Rays of the same movie, please upscale the DVD to Blu-Ray resolution and check whether madVR shows the correct AR or whether the image is slightly squeezed.

P.S: Sneals2000, if you find anything else wrong in madVR, please let me know!
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Old 9th December 2012, 17:34   #16106  |  Link
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Some DVDs are made with ITU scaling in mind, some are not (in which case they are scaled to exactly 4:3 or 16:9).
I guess you can learn which studios do what, but there's no way of telling for sure except to find and look at round objects, or compare with a HD version.
If you have two DVDs with different scalings, your setup *will* play one of them wrong.

According to ITU, 4:3 DVDs are scaled to 15:11 and 16:9 DVDs are scaled to 20:11. For both PAL and NTSC.

Guidelines I've heard for when a DVD is likely to *not* have ITU scaling: (not guaranteed to be correct)
- The DVD was produced in or after 2006.
- There is very little cropping at the sides (image width is closer to 720 than 702).

Last edited by ajp_anton; 9th December 2012 at 17:41.
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Old 9th December 2012, 18:06   #16107  |  Link
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All PAL and NTSC DVDs have such problems, 702x576 for PAL and 702.222222...x480 for NTSC.
Here is a quick guide for those aspect ratio stuffs.
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Old 9th December 2012, 19:08   #16108  |  Link
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Sorry if this was covered I could not find an answer.

What is the best way to upgrade to the latest madVR release without losing existing settings?
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Old 9th December 2012, 19:09   #16109  |  Link
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Originally Posted by andydufresne View Post
Sorry if this was covered I could not find an answer.

What is the best way to upgrade to the latest madVR release without losing existing settings?
Just replace all of the files from the new madVR zip into your previous madVR directory. The settings are stored in the .bin file and the registry.
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Old 9th December 2012, 19:25   #16110  |  Link
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Originally Posted by madshi View Post
A debug log might help. What does "extended display" mean exactly? You mean some special mode of dual monitor setup? Does the problem only occur in that one mode? In all other modes playback works just fine?
http://netload.in/dateiCAu3jjDSru/madVR-log.zip.htm Extended display is a non-primary (no taskbar on all but Win8) in an extended setup of multi monitors. Happens in both windowed and exclusive mode.

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Not at the moment, but it's on my to do list.
Ok, worth considering the labels I mentioned? hddvd/hd-dvd could fixed with *hd* having a higher priority then *dvd*

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Anamorphic PAL is 1024x576 after aspect ratio correction. So width must be higher than 1024, or height bigger than 576 to quality for "HD".
if par=4:3 and width <721 matrix=601
if par=16:9 and width <721 matrix=601
if width <721 matrix =601 else matrix=709
would this work?

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To my eyes in the very few test images I saw, spline144 looked oversharpened. But I have to preserve final judgement because I simply didn't have enough time to evaluate it properly. Anyway, now is not the time to talk about FineSharp or alternatives. Busy with other stuff atm...
Thought I'd mention it before you started working on it.

Are you guys sure 702 is actually the correct width of dvd's? I've always heard (mostly from an electronics engineer) 703 PAL and 706 NTSC which is typically rounded to 704.

Last edited by turbojet; 9th December 2012 at 19:29.
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Old 9th December 2012, 19:41   #16111  |  Link
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Just replace all of the files from the new madVR zip into your previous madVR directory. The settings are stored in the .bin file and the registry.
Thank you
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Old 9th December 2012, 20:50   #16112  |  Link
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The thing that confuses me about all of this is that I have some videos from DVDs that are 704x576, but if I scale them to 1024x576 they look stretched. Scaling them to 1001x576 (so there are slim black bars on the side of the 16:9 frame) looks correct. Same with some of my DVDs that are 720x576 - they look fine at 1024x576, at 1050x576 they look stretched.

I suppose it could just be that the DVDs were made "incorrectly".

Fortunately this isn't an issue in the HD world!
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Old 9th December 2012, 21:02   #16113  |  Link
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I have a question madshi. I m using SVP Frame (probably familiar with you http://www.svp-team.com/wiki/Frame_interpolation_overview) and I using an option in SVP Frame called 'to screen refresh rate' this means that eg. 23,976 content is frame interpolated to the refresh rate that you set in the NVIDIA control panel. The author of SVP frame told me tha t my goal is to get 59.94 reported by madVR and that this can be done by choosing the 59 profile (NOT the 60!) in the nvidia control panel. He is right because when I choose 59 in the nvidia control panel madVR reports 59.94XXX. madVR also tells me I get 1 dropped frame every 21 minutes. This would mean approx. 3 per our. But the strange thing is that I get 20-30 dropped frames per hour. You might have an idea what could be the cause of this?

(ps. I m bitstreaming and ReClock is no option for me because I need bitstreaming for my D-Box decoder)
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Old 9th December 2012, 22:10   #16114  |  Link
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Originally Posted by DragonQ View Post
The thing that confuses me about all of this is that I have some videos from DVDs that are 704x576, but if I scale them to 1024x576 they look stretched. Scaling them to 1001x576 (so there are slim black bars on the side of the 16:9 frame) looks correct. Same with some of my DVDs that are 720x576 - they look fine at 1024x576, at 1050x576 they look stretched.

I suppose it could just be that the DVDs were made "incorrectly".

Fortunately this isn't an issue in the HD world!
I just explained this. These DVDs don't follow ITU scaling and just assume a 64:45 stretch making 720x576 exactly 1024x576 and 704x576 into ~1001x576.
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Old 10th December 2012, 00:13   #16115  |  Link
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Originally Posted by Sneals2000 View Post
For 16:9 SD ITU 601 video :
720x576 scales to 1050x576 square pixels (i.e. the full 720x576 frame is wider than 16:9)
702x576 scales to 1024x576 square pixels (i.e. crop 9 samples from either side of the 720x576 frame to isolate the central 16:9 image area)
Well that explains why I have never been able to get this test pattern from DVE to display correctly, whether it was back in the day of analogue CRTs, upscaling DVD players on HDTVs, or HTPC-based playback. It always looked slightly oval.

With the CRT you could at least correct it to be a circle by adjusting the image width. (and with MPC-HC you can almost fix it by either adjusting the image to be slightly wider, or slightly shorter - but it's not exact)

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Originally Posted by madshi View Post
Call for test: Anyone who has DVDs and Blu-Rays of the same movie, please upscale the DVD to Blu-Ray resolution and check whether madVR shows the correct AR or whether the image is slightly squeezed.
Unfortunately, I have made it a habit to get rid of the DVD version of a film as soon as I get the Blu-ray release, so I don't have many left to compare.

Sample 1:Sample 2:I had to shift the position on them slightly as they didn't match identically, but it appears that 720x576 to 1024x576 is what studios assume.

As an aside, here's that first sample with Lanczos 3 AR scaling, and SoftCubic 80. This is why I tend to prefer softer scaling algorithms with commercial DVDs.
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Old 10th December 2012, 00:46   #16116  |  Link
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@Sneals2000,

thanks a lot for your informative post, this is the first time I hear of that.
Yep - it comes as a surprise to many - even though it's an inherent part of ITU 601 - the core SD digital video standard. It's a direct result of 13.5MHz sampling. Sorry if it seems a bit pedantic - but when I saw 1050x576 being slightly dissed, I had to pipe up.

Whilst analogue TV is effectively almost dead (though it may surprise many to know that very high quality analogue signals are still in widespread use in TV studios - particularly SD studios - though some HD cameras also use the same systems - to connect studio cameras to their control rooms down triax cables) - digital TV standards are still based on them.

This is particularly important in studios and live production areas - where you don't want delays - and so don't use frame stores or significant compression.

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I do have a few worries, though. Would you mind to address them?

(1) Does this only apply to BBC / UK, or to all PAL content world wide?
It applies to all correctly handled 576/50i content in 4:3 and 16:9. This should be everything, but particularly content mastered by broadcasters and those who supply broadcasters (like movie studios) who generally adhere to international standards like ITU 601.

It's not specific to the BBC or the UK - though the BBC may have been better at explaining it to their suppliers and internal production areas and may also stick to the standards more accurately than some others. (Though I know there was a visible issue for a while in the BBC One HD / SD chains causing width changes)

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(2) Does this also apply to PAL DVDs?
Yes - it should apply to all ITU 601 content - DVDs, Digital broadcasts, digital VT recordings etc. irrespective of production or distribution.

(Note I say should)

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(3) How about NTSC? Any similar sheenigans going on there, too?
Yes - though NTSC is slightly more confusing to get a grip on because of the change from 486 to 480 active lines with the introduction of DV and MPEG2 (though ISTR D1/D2 and I think D3 captured 486 lines). I've not worked extensively with NTSC but I believe it is based on 711x486 (but with 6 lines cropped when analogue NTSC was digitised I'm not sure what has happened). It's a lot less clear though (and I'm based in 50Hz land so have never really had to deal with it)

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I'm especially wondering about PAL DVDs. Since DVDs are all digital, and most DVDs are being encoded directly from the 2K (or higher) masters, I'm wondering if DVD encoding houses encode AR to 720x576 or to 702x576?
If they are doing things correctly they will encode the 16:9 image to the central 702x576 frame. Of course there is no guarantee that every DVD mastering house will do this. In fact I bet some or many don't. Particularly those working entirely in the file-based domain with IT-based workflows.

DVDs mastered from broadcast SD video sources (rather than file-based downconversion of HD sources) should definitely be properly ITU 601 compliant though.

Certainly HD 1920x1080 broadcasts simulcast in SD should be converted to 702x576 - and as more and more broadcasters now originate in HD, there should be a lot of empty 9 samples either side! (Assuming downconversion is being done correctly...) As I've mentioned - lots of broadcasters use 704x576 rather than 720x576 for broadcast for this reason. Why bother encoding 16 samples every line that a viewer should never see?

AIUI most standalone hardware DVD players follow these standards for replay... Those with upscaling should scale the central 702x576 area to 1920x1080 or 1280x720.

Quote:
Thanks!

Call for test: Anyone who has DVDs and Blu-Rays of the same movie, please upscale the DVD to Blu-Ray resolution and check whether madVR shows the correct AR or whether the image is slightly squeezed.

P.S: Sneals2000, if you find anything else wrong in madVR, please let me know!
It's a complicated issue and one that even broadcast manufacturers occasionally get wrong. However ITU 601 is very clear - it's based on a 13.5MHz sampling rate, and 576/50i is entirely based on 52us active lines in a 64us total line.

I'd not be at all surprised to find a significant number of DVDs mastered with a 1920x1080 or higher source scaled directly to 720x576 rather than to the central 702x576 area. Incorrectly.

I'd also not be surprised if some HD downconversion from 1920x1080 or 1280x720 to SD was incorrectly scaled to 720x576 rather than 702x576. Doesn't make it right...

At the end of the day it's going to be a very small geometric distortion, and I suspect there are significant numbers of DVDs mastered in both ways. However ITU 601 is really clear - and all SD digital video based on 720x576 should be ITU 601 compliant - and anything handling ITU 601 content should really follow the standards I would suggest. Just because others don't doesn't mean everyone shouldn't...

It might be a few years old but : http://www.quantel.com/repository/files/library_DigitalFactBook_20th.pdf is a very useful bit of background. Quantel were one of the main drivers of digital SD video. The entries on Aspect Ratio confirm the 702x576 and 711x486 ratios.

Last edited by Sneals2000; 10th December 2012 at 01:07.
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Old 10th December 2012, 00:59   #16117  |  Link
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Does that not become a problem if there are more 720x576 SD videos than 702x576 videos out there? I dunno if there is, just that it might be a possibility. I don't think any of the software I've used for video playback properly trims the outer 18 pixels and scales the inner 702 pixels to 1024, and I've rarely noticed aspect ratio being incorrect.

Now I'm curious I might grab recordings of BBC One HD and BBC One to see how MPC-HC and MediaPortal handle them.

EDIT: Yep, both MPC-HC and MediaPortal just stretch the full 720 pixels to 1024, resulting in a slightly squished image and thin black bars on either side. Screengrabs:

HD | SD | SD Fixed

However, just because the BBC conforms to ITU 601 doesn't mean all SD channels do, so it's likely very complicated. Most SD channels are 704x576 for a start, so if these are being fully stretched to 1024 then there'll be minimal distortion in comparison. I have no idea how 544x576 works in terms of ITU 601 active area though.
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Last edited by DragonQ; 10th December 2012 at 01:23.
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Old 10th December 2012, 01:11   #16118  |  Link
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Originally Posted by 6233638 View Post

Sample 1:Sample 2:I had to shift the position on them slightly as they didn't match identically, but it appears that 720x576 to 1024x576 is what studios assume.

As an aside, here's that first sample with Lanczos 3 AR scaling, and SoftCubic 80. This is why I tend to prefer softer scaling algorithms with commercial DVDs.
Hmm - yet the SD grabs are slightly narrower with black samples either side. Annoying. It's as if the standard is being partially followed...
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Old 10th December 2012, 01:23   #16119  |  Link
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Does that not become a problem if there are more 720x576 SD videos than 702x576 videos out there? I dunno if there is, just that it might be a possibility. I don't think any of the software I've used for video playback properly trims the outer 18 pixels and scales the inner 702 pixels to 1024, and I've rarely noticed aspect ratio being incorrect.
It's a very minor distortion - only noticable in most cases if you are a critical viewer looking at perfect circles - or if the same content is switched through two chains, only one of which is properly compliant (as happened with BBC One HD/SD at one point...)

Quote:
Now I'm curious I might grab recordings of BBC One HD and BBC One to see how MPC-HC and MediaPortal handle them.

EDIT: Yep, both MPC-HC and MediaPortal just stretch the full 720 pixels to 1024, resulting in a slightly squished image and thin black bars on either side.
Yep - that's what should happen with properly mastered SD video that is mastered to that international standards (i.e. ITU 601) An HD 16:9 1920x1080 or 1280x720 source should be downscaled to 702x576 and sit in the middle of the 720x576 frame - as can be seen by BBC One HD and BBC One SD. I'd hope Channel Four and ITV1 HD and SD were similar. (Particularly as Channel Four is played out by the same people as play out BBC channels - Red Bee Media - formerly BBC Broadcast)

Quote:
However, just because the BBC conforms to ITU 601 doesn't mean all SD channels do, so it's likely very complicated.
It isn't a BBC vs other broadcasters issue. The BBC doesn't build it's equipment in house after all - it buys it from Sony, Panasonic, GrassValley, Avid, JVC, Ikegami, Crystal Vision, Snell, Axxon etc.... It's a standards compliance issue. ITU 601 is a clear standard - but it isn't always followed - particularly in the software domain (though many software developers do follow it - particularly if they want to sell to broadcasters). I know that the BBC are quite careful in the software domain - particularly with HD/SD conversion. (They also use FFMBC rather than FFMPEG for broadcast conversion as this fork does better with some broadcast video specific stuff)

If you build a broadcast chain with properly ITU 601 compliant kit (and software) you'll get ITU 601 compliant video... It's the SD digital video standard that DVD, DVB, Studios, Camcorders etc. are based on for SD video.

I'd expect most mainstream broadcasters will have SD and HD video very similar to the BBC. They'll be using the same type of kit, and it isn't as if there is a 720 vs 702 switch you flick in most of this stuff.

As has been said many broadcasters run 704x576 (nearest MPEG multiple to 702x576) and scaling 704x576 to 1024x576 will be a tiny distortion.

Not sure about 544x576 - however I believe that the standard approach is to crop 4 samples (2 each side) to generate a 540x576 frame, and then scale this to 720x576 (to keep the resampling neat as a 4 to 3 re-sampling ratio). This is because the 544x576 is just an interim format created by resampling a 720x576 source. I think this means that the 4:3 or 16:9 image corresponding to the 702x576 portion occupies the central 526.5 samples of the 544x576 image... But I may be very wrong. And I suspect I'm not alone if I am!

(And I think I've heard of 528x576 being used - as that is a neater MPEG multiple - similar to 702 vs 720)

it IS a tiny aspect ratio issue (if you look at the two BBC One SD grabs you'd probably not notice one was slightly out if you only saw it in isolation - and I'm sure many CRTs had worse geometry errors back in the day!) - and I'm not trying to make a huge thing about it (though I do believe that if you have standards you should stick to them)

I just saw a post questioning 1050x576 and thought I'd comment on it.

(I only came to the thread to decide what video card to buy!)

Last edited by Sneals2000; 10th December 2012 at 01:47.
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Old 10th December 2012, 01:52   #16120  |  Link
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I have to admit that I never quite understood the whole 720x576 being 4:3 AR with non-square pixels story...but hey, they make 1024x768 Plasma TV's with a 16/9 AR, so I assumed that non-square pixels were an acceptable practice in the video world.

So how do you know the actual AR of a 720x576 FS stream then? Are you saying that 720x576 FS is not/never meant to be watched with a 4:3 AR? It sure looked OK to me
I'd say that you should always assume 720x576 video is ITU 601 compliant. It's the only proper standard for 720x576 video that I know of...

That means the 4:3 or 16:9 video is within the 702x576 central area. There is no other offical standard.

Of course some mastering may not follow ITU 601 and not follow any official standard and instead map the 720x576 image to be 4:3 or 16:9. That is non-standard.

I guess there's no real way of knowing...

Given the relatively small aspect ratio differences involved - I doubt many people are that worried... On the other hand - given the huge noise some make about <16 and >235 levels being preserved I'm surprised...
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direct compute, dithering, error diffusion, madvr, ngu, nnedi3, quality, renderer, scaling, uhd upscaling, upsampling

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