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.

 

Go Back   Doom9's Forum > Video Encoding > High Efficiency Video Coding (HEVC)

Reply
 
Thread Tools Search this Thread Display Modes
Old 10th January 2016, 17:18   #21  |  Link
movmasty
Registered User
 
Join Date: Feb 2002
Posts: 970
Some Appalachian self.constructed board
movmasty is offline   Reply With Quote
Old 10th January 2016, 19:40   #22  |  Link
Selur
Registered User
 
Selur's Avatar
 
Join Date: Oct 2001
Location: Germany
Posts: 5,848
Quote:
...Is the hour? It is 80 minutes.
A good movie is 2 hours, and this 3 hours are 240 minutes
LoL, wanted four instead of 3 hours.

Quote:
4% of that would be 0.193 bit/frame pixel, which would be 400 bit/frame.
How do you do that?
0.192 'frame pixel' and 1920x1080 pixel per frame = 400 000 and then I lost the 1000 (damn really need more sleep)
__________________
Hybrid here in the forum, homepage
Selur is offline   Reply With Quote
Old 11th January 2016, 12:50   #23  |  Link
foxyshadis
ангел смерти
 
foxyshadis's Avatar
 
Join Date: Nov 2004
Location: Lost
Posts: 9,413
Quote:
Originally Posted by movmasty View Post
...Is the hour? It is 80 minutes.
A good movie is 2 hours, and this 3 hours are 240 minutes

If its +2-4% on bitrate/framepixel, its +2-4% on bitrate or size as well.
I like numbers, but there are too many in your post.
what is the distance of Centauri? 4Ly, 480 days in a year, 32 hours in a day, 80 mins in a hour, 80 secs in a min.....very big!

The difference exist, but is very smaller mod16xmod8 is still very good

If you really seek for total compatibly and universal rendering should use mod64xmod64.
that gives few res available
for 4:3 256x192 and multiples
for 16:9 1024x576 and multiples
for 2.35 2560x1088 and multiples.
I don't think you understand how modX is decoded. Once you're past the hurdle of requiring decode and output resolutions to be identical, without which 1080p wouldn't exist, any other resolution is OK down to mod 8x2 (for the usual 4:2:0), and mod 2x2 on nearly all hardware. At this point the ones with bugs even in their horizontal conversion are extremely rare, it's a long solved problem.

And maybe tamp down on the sarcasm, or whatever it is, and answer questions and correct mistakes directly instead of throwing out non sequiturs.
__________________
There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order.
foxyshadis is offline   Reply With Quote
Old 17th February 2016, 13:10   #24  |  Link
bcn_246
Registered User
 
bcn_246's Avatar
 
Join Date: Nov 2005
Location: UK
Posts: 146
Widescreen NTSC DVDs are not quite 16:9 (1.77778:1). The standard NTSC DVD has a resolution of 720x480. It also has a signalled Pixel Aspect Ratio of 40:33. This tells the decoder to stretch the image out horizontally. This makes the actual Aspect Ratio 1.81818:1 (720/480 = 1.5, 1.5 x (40/33) = 1.818...).

480 x 1.81818 = 872, so 480p DVDRips should really 872x480. However, 872 is not mod16. Ideally clips should be mod16, however with newer decoders it seems far less important (I have yet to find any player that struggled with anything other than mod2). If you want to be safe, go with 864x480 (1.8:1) and crop to reduce error.

It is worth bearing in mind that some mastering facilities may have made the mistake of assuming a DVD to be 16:9 also. When I can I have a look through the DVD for squares or circles to check what the actual aspect ratio is (logos in the credits are always a good indicator). If you do find the DVD has been mastered at 16:9 then I would go with 852x480 (again, not mod16, so go with 848x480 if you want to be safe).

It is also worth bearing in mind that when muxing to MKV (with MKVToolNix GUI) you can manually set the playback Aspect Ratio (see screenshot). While I don't use this to encode at Aspect Ratios far off (not all devices read this header correctly) it is useful to get things exact. For example, if you encode at 848x480 and wish to have it (when possible) be resized to 1920x1080 on your display it is worth setting the flag (although an error of 0.63% is really not much of an issue).

Also, for reference PAL DVDs are also not exactly 16:9 (1024x576). They use an aspect ratio of 16:11, so 576p content should be really be resized to 1048x576 (or 1040/1056 if you wish to keep it mod16).

Hope this helps explain things,

Ben

Last edited by bcn_246; 17th February 2016 at 13:19. Reason: cleanup
bcn_246 is offline   Reply With Quote
Old 24th February 2016, 10:49   #25  |  Link
foxyshadis
ангел смерти
 
foxyshadis's Avatar
 
Join Date: Nov 2004
Location: Lost
Posts: 9,413
Quote:
Originally Posted by bcn_246 View Post
Widescreen NTSC DVDs are not quite 16:9 (1.77778:1). The standard NTSC DVD has a resolution of 720x480. It also has a signalled Pixel Aspect Ratio of 40:33. This tells the decoder to stretch the image out horizontally. This makes the actual Aspect Ratio 1.81818:1 (720/480 = 1.5, 1.5 x (40/33) = 1.818...).
Widescreen NTSC DVDs are exactly 16:9, because the active area is 704x480, not 720x480. Some discs are encoded that way, most are 720. Some discs violate the standard and some players ignore it, but the 704 middle pixels are what's supposed to be displayed even when the encode is 720. Most commercial DVDs will have 8 pixels of dark or black pixels on each side, though it's fairly often off-center, and sometimes the active frame is edge-to-edge and should be treated as having a different aspect ratio. (Though the difference is small.) That's the trouble with having thousands of companies putting out releases, quite a few of them screw it up.

There have been quite a few threads here about this problem.
__________________
There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order.
foxyshadis is offline   Reply With Quote
Old 25th February 2016, 04:19   #26  |  Link
MeteorRain
結城有紀
 
Join Date: Dec 2003
Location: NJ; OR; Shanghai
Posts: 591
Quote:
Originally Posted by movmasty View Post
in fact 704 x 40/33 = 853.333
Good catch, I typo'd.
MeteorRain is offline   Reply With Quote
Old 25th February 2016, 14:38   #27  |  Link
pandy
Registered User
 
Join Date: Mar 2006
Posts: 1,044
Quote:
Originally Posted by movmasty View Post
Amiga? Commodore
Nope - Comodore Amiga is:
at first non ITU video source
at second capable to do MOD16 in horizontal and any MOD1 in vertical
at third it can use (ICS/OCS) 2 pixel clocks and (ECS/AGA) 3 different pixel clocks
at fourth is Amiga is not capable to decode H.265 with reasonable speed even with most fastest accelerator board (for today such as Apollo which is something around 150MHz MC68060 i.e. somewhere around 200MHz 486DX).

And to not be completely OT: H.265 is not optimized for SD resolution (compression efficiency will be significantly bellow promised 50%).
pandy is offline   Reply With Quote
Old 25th February 2016, 19:17   #28  |  Link
benwaggoner
Moderator
 
Join Date: Jan 2006
Location: Portland, OR
Posts: 2,922
Quote:
Originally Posted by pandy View Post
And to not be completely OT: H.265 is not optimized for SD resolution (compression efficiency will be significantly bellow promised 50%).
I don't know if that is true. Implementation maturity might not be there to be able to deliver x264 quality at half the bit rate in x264's sweet spot, but we're not THAT far off with 1.9 now. 50% is probably achievable with some content (low noise).
__________________
Ben Waggoner
Principal Video Specialist, Amazon Prime Video

My Compression Book
benwaggoner is offline   Reply With Quote
Old 26th February 2016, 19:17   #29  |  Link
pandy
Registered User
 
Join Date: Mar 2006
Posts: 1,044
Quote:
Originally Posted by benwaggoner View Post
I don't know if that is true. Implementation maturity might not be there to be able to deliver x264 quality at half the bit rate in x264's sweet spot, but we're not THAT far off with 1.9 now. 50% is probably achievable with some content (low noise).
Well it is proven (sort of) that even HD content is to small for H.265.
Even if H.265 will deliver few % gain then IMHO is not worth all fuzz behind it.
But yes, i never saw objective test with focus on how H.265 scaling with source resolution - based on experience with previous codecs i don't expect different behavior.
pandy is offline   Reply With Quote
Old 26th February 2016, 21:59   #30  |  Link
benwaggoner
Moderator
 
Join Date: Jan 2006
Location: Portland, OR
Posts: 2,922
Quote:
Originally Posted by pandy View Post
Well it is proven (sort of) that even HD content is to small for H.265.
Even if H.265 will deliver few % gain then IMHO is not worth all fuzz behind it.
Yes, not much reason to use HEVC for a few %. But even for SD I'd expect >25% for a lot of content.

The advantage of HEVC goes up with high resolutions; it's >50% at 3840x2160. But it's not JUST high resolutions.
__________________
Ben Waggoner
Principal Video Specialist, Amazon Prime Video

My Compression Book
benwaggoner is offline   Reply With Quote
Old 29th February 2016, 18:41   #31  |  Link
YamashitaRen
Registered User
 
Join Date: Apr 2014
Location: France
Posts: 33
Can you elaborate on what makes HEVC more interesting the higher the resolution goes ?
Are we talking about transparency, metrics, perceptual quality ?
__________________
Want to OCR hardsubs ? Try YoloCR : https://v.gd/wqvAF1
YamashitaRen is offline   Reply With Quote
Old 29th February 2016, 21:39   #32  |  Link
benwaggoner
Moderator
 
Join Date: Jan 2006
Location: Portland, OR
Posts: 2,922
Quote:
Originally Posted by YamashitaRen View Post
Can you elaborate on what makes HEVC more interesting the higher the resolution goes ?
Are we talking about transparency, metrics, perceptual quality ?
Larger block/TU sizes are probably the primary thing that helps relative efficiency at frame size goes up. And UHD, you can find flat areas where 32x32 works, while H.264 would be stuck with 8x8.

Lots of other HEVC features provide efficiency improvements irrespective of frame size. So there's a base efficiency improvement, and an additional frame size differential improvement.
__________________
Ben Waggoner
Principal Video Specialist, Amazon Prime Video

My Compression Book
benwaggoner is offline   Reply With Quote
Old 1st March 2016, 11:20   #33  |  Link
YamashitaRen
Registered User
 
Join Date: Apr 2014
Location: France
Posts: 33
Oh I see... Thanks for your answer
__________________
Want to OCR hardsubs ? Try YoloCR : https://v.gd/wqvAF1
YamashitaRen is offline   Reply With Quote
Old 6th March 2016, 21:01   #34  |  Link
kolak
Registered User
 
Join Date: Nov 2004
Location: UK
Posts: 2,394
Quote:
Originally Posted by foxyshadis View Post
Widescreen NTSC DVDs are exactly 16:9, because the active area is 704x480, not 720x480. Some discs are encoded that way, most are 720. Some discs violate the standard and some players ignore it, but the 704 middle pixels are what's supposed to be displayed even when the encode is 720. Most commercial DVDs will have 8 pixels of dark or black pixels on each side, though it's fairly often off-center, and sometimes the active frame is edge-to-edge and should be treated as having a different aspect ratio. (Though the difference is small.) That's the trouble with having thousands of companies putting out releases, quite a few of them screw it up.

There have been quite a few threads here about this problem.
Well, when you follow this BBC guide (which I assume is correct and as per old analog standard) than if you scale HD master to SD (with 8 pixels padding) than when you watch it on LCD/Plasma etc it circle won't be circle. When you do the same on old CRT than it will be fine.
My own practical test shown that BBC rules don't work for modern TVs. Adobe adopted these rules some time ago and now their HD to SD scaling has black bars on side which I'm not that sure is correct for modern TVs (as they use square pixels and seams to have no compensation for "old standard"- Sony broadcast monitors have special setting for it).

Last edited by kolak; 6th March 2016 at 21:03.
kolak is offline   Reply With Quote
Old 7th March 2016, 23:26   #35  |  Link
benwaggoner
Moderator
 
Join Date: Jan 2006
Location: Portland, OR
Posts: 2,922
Quote:
Originally Posted by kolak View Post
Well, when you follow this BBC guide (which I assume is correct and as per old analog standard) than if you scale HD master to SD (with 8 pixels padding) than when you watch it on LCD/Plasma etc it circle won't be circle. When you do the same on old CRT than it will be fine.
My own practical test shown that BBC rules don't work for modern TVs. Adobe adopted these rules some time ago and now their HD to SD scaling has black bars on side which I'm not that sure is correct for modern TVs (as they use square pixels and seams to have no compensation for "old standard"- Sony broadcast monitors have special setting for it).
I think the challenge comes from being able to do 16:9 704x576 in broadcast but not DVD; DVD only allows <720 widths with 4:3 for some long-forgotten reason.

Optimally encode to 704x576 from 16:9 with full raster and no black bars and standard PAL sample aspect ratio, and circles should be circles.
__________________
Ben Waggoner
Principal Video Specialist, Amazon Prime Video

My Compression Book
benwaggoner is offline   Reply With Quote
Reply

Tags
480p, hevc, x265

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +1. The time now is 14:01.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2019, vBulletin Solutions Inc.