Welcome to Doom9's Forum, THE in-place to be for everyone interested in DVD conversion. Before you start posting please read the forum rules. By posting to this forum you agree to abide by the rules. |
4th December 2019, 11:22 | #29021 | Link | |
Registered User
Join Date: May 2006
Posts: 3,997
|
Quote:
BD-RB uses the mpeg4 SAR of 40:33 = 1.212121... for x264 16:9 anamorph 720x480 encoding. It is AVC/mpeg4/blu-ray compliant and a very close approximation to the ITU PAR of 1.212945, but exhibits the well known aspect ratio difference of 2.3% compared to the 'Generic' PAR of 1.1852. This slight difference is normally not even noticed. As far as I remember you can't change the SAR in BD-RB to avoid non-compliant mpeg4/AVC video. Thinking about it and hoping I remembered all this correctly, I am now wondering why BD-RB added top and bottom borders rather than left and right 8 pixels each. Did your original already come with any borders? Did you resize? What is your playback scenario? Does your player/TV add the top/bottom borders rather than BD-RB? Does your player read the SAR or force 16:9 DAR playback? |
|
4th December 2019, 12:37 | #29022 | Link | |
Registered User
Join Date: Jun 2018
Location: Dorset
Posts: 164
|
Quote:
also what is the file size of said 2160p file ? Last edited by jdobbs; 7th December 2019 at 15:26. |
|
4th December 2019, 15:31 | #29023 | Link |
Moderator
Join Date: Oct 2001
Posts: 20,975
|
I'd say it's more likely that the source is seriously flawed. Players have built-in downscaling to cover being attached to non-UHD monitors and other non-compliance issues.
Last edited by jdobbs; 4th December 2019 at 15:38. |
4th December 2019, 15:35 | #29024 | Link | |
Moderator
Join Date: Oct 2001
Posts: 20,975
|
Quote:
[Edit] In fact, several of the files I've looked at (that I had previously tested) are actually 3840x1600, which seems to be a fairly common format for reencoded MKV/MP4 files (even though the file title says "2160p"). In the end it may turn out to be the non-compliant sizing that is the real issue. But the original point is still valid. People may think they are watching these in UHD when they are actually simply watching an upscaled representation of it from a picture that was downscaled to 1080p. I know that is true at least on my Sony player, I can't speak for other units. Last edited by jdobbs; 7th December 2019 at 15:28. |
|
4th December 2019, 17:20 | #29026 | Link |
Moderator
Join Date: Oct 2001
Posts: 20,975
|
Placebos work. That's the reason so many "natural cures" are sold.
I'll take of a couple of these and reencode them with the borders that bring it up to 2160. I suspect that will fix the issue. I have to say... I'm pretty impressed with the UHD blu-rays I've been watching since getting my UHD TV. It's more noticable than I thought it would be (on some discs, not all). Some of the reviews I read say that most people won't see the difference between HD and UHD from a normal viewing distance. But to me it looks more crisp (from about 10 feet where I usually watch). But then again... there's always the placebo effect. Last edited by jdobbs; 4th December 2019 at 17:26. |
4th December 2019, 17:25 | #29027 | Link | |
Registered User
Join Date: May 2007
Location: Wisconsin
Posts: 2,132
|
Quote:
If I play a MKV file thru my Samsung and if it is 1920x800, the player will add the letterbox bars. But, if I author the file onto a BD, the player will vertically expand the video to fill the screen. Those cropped videos are a PITA.
__________________
My Total Eclipse 2017 Photos My Nov 2019 Game of Thrones Tour My NEOWISE Comet Photos 2020 Last edited by jdobbs; 7th December 2019 at 15:29. |
|
4th December 2019, 19:20 | #29028 | Link |
Life's clearer in 4K UHD
Join Date: Jun 2003
Location: Notts, UK
Posts: 12,227
|
Indeed.... It's a shame that the Blu-ray 'HD' disc format does not support 'cropped' video. And even a bigger shame that the Blu-ray 'UHD' disc format followed suit
__________________
| I've been testing hardware media playback devices and software A/V encoders and decoders since 2001 | My Network Layout & A/V Gear |
|
4th December 2019, 20:40 | #29029 | Link | |
Registered User
Join Date: Jun 2010
Location: Germany
Posts: 205
|
Quote:
And at 5 feet even the blindest will see a difference |
|
5th December 2019, 22:28 | #29030 | Link | |
Registered User
Join Date: Dec 2011
Posts: 148
|
Quote:
How do you do that? Adding "black bars" to cropped videos? Last edited by Glarioo; 5th December 2019 at 22:32. |
|
7th December 2019, 04:49 | #29035 | Link | |
Registered User
Join Date: Nov 2019
Posts: 9
|
Quote:
So I decided to keep it at 720x480, but the only way I could get a perfect copy was to grab the output of lastcmd.txt after each pass and manually recode each affected file in x264 replacing --sar 40:33 with --sar 32:27, then remuxing to m2ts myself. I then replaced the files created by BDRB with my own, which obviously broke the chapters. I fixed this by getting BDRB to rebuild the copy containing the replaced files, this time with no encoding of the video (as the file sizes were now correct for BD25). All menus and chapters work fine and the video is identical to the original. I've no idea if the new copy is blu-ray compliant, but it works perfectly on both the PS4 and in J River media centre. Obviously this was a very laborious way of doing a 3 disc set, but I could find no other method, and wondered if I could have done anything to make BDRB work automatically with these discs. |
|
7th December 2019, 19:03 | #29036 | Link | |
Registered User
Join Date: Apr 2003
Location: Within the main Source.
Posts: 895
|
Quote:
I still adore 1080P, but I don't really embrace the 4K thing as so many. Yes, video looks larger, from my phone, yes, outside video of events and nature are really sweet that way. But movies and T.V. shows where there are a lot of makeup and and all that...acne, and stuff...I don't see any reason for that to be really huge. Now, you present Mars photos that large, and other pictures of our planets...I'm alllllllll in! I want to see all that very clearly. I guess it's a "catch 22" to me. Hmm..
__________________
Life is not a journey to the grave; but rather to skid out broadside, thoroughly used, torn and warn and loudly proclaim; WOW; What a ride!!! Soon, I'm going to do it AGAiN in different skin!! |
|
8th December 2019, 22:08 | #29038 | Link |
Registered User
Join Date: Nov 2019
Posts: 9
|
Yes, the 3 original discs are BD50. I was simply creating a backup of each onto 3 separate 25GB discs. The SD video files inside the m2ts containers are mpeg-2.
When starting the x264 encoder, the first line shows "lav [info]: 720x480i 32:27 @ 30000/1001 fps (cfr)". If you import the same file into Handbrake, the dimensions tab shows: "Source 720x480, PAR 32/27". Those references to 32:27 made me suspect the black bars on the BDRB copy were caused by the SAR 40:33 in BDRB's x264 command line. I found that if I used SAR 32:27, or if I just omitted the SAR parameter completely, both scenarios produced video identical to the source, with no black bars. |
9th December 2019, 03:09 | #29039 | Link |
Registered User
Join Date: May 2007
Location: Wisconsin
Posts: 2,132
|
The SAR of 40:33 is based upon a 704x480 video. With NTSC analog conversion to digital, 8 pixels are removed from each side of the 720 video to get you the 704 video. But, if the 16 total pixels are not removed, you end up with the situation you found yourself in. You could have added an AVISynth plugin command to crop 8 pixels off each side and you should have come up with the correct result [crop(8,0,-8,0)].
The reason for doing the cropping is that in correctly digitized video, there are about 8 pixels of vertical black on each side of the video. By removing it, you get video out to each side, without any annoying vertical black bars. |
11th December 2019, 03:27 | #29040 | Link |
Registered User
Join Date: Nov 2019
Posts: 9
|
Thanks for your suggestion re cropping. I gave it a try and found that it did indeed remove the bars. The bars had been at the top and bottom, not the sides, but cropping 8 pixels from each side made them disappear. Compared with the original, the height of the picture was now the same, with no part of the original frame missing. The width of the picture was very slightly stretched, with a very small part of each side cropped. Viewed in isolation, I probably would not have noticed, so that's preferable to the black bars.
What I can't figure out is this: If I get BD-RB to convert it from SD to 1080, there are no bars, and nothing is cropped from the edges. Also, given that the source disc has the SAR of 32:27, does that mean the original BD is not compliant? Or it is allowed for MPEG-2 on BD but not AVC? That may explain why they stuck with MPEG-2 coding on the original. |
|
|