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. |
28th January 2006, 17:45 | #41 | Link | ||
Registered User
Join Date: Jul 2005
Posts: 240
|
Quote:
Quote:
Also I checked the log file and found the following in it. Track 1 of 'D:\Projects\Red Eye\Red Eye.mkv': Extracted the aspect ratio information from the MPEG-4 layer 10 (AVC) video data and set the display dimensions to 844/352.
__________________
Toronto,ON |
||
29th January 2006, 00:35 | #42 | Link | ||||
Registered User
Join Date: Apr 2005
Posts: 1,740
|
Quote:
Quote:
Quote:
Quote:
|
||||
29th January 2006, 01:35 | #43 | Link | |
Registered User
Join Date: Jul 2005
Posts: 240
|
Quote:
__________________
Toronto,ON |
|
29th January 2006, 09:37 | #44 | Link | |
Registered User
Join Date: Apr 2005
Posts: 1,740
|
Quote:
|
|
29th January 2006, 10:14 | #45 | Link |
Registered User
Join Date: Aug 2003
Posts: 43
|
digitaldivide,
why is there a discrepancy between which display height you set. 354 or 352. if its 352, then the sar given by megui (720/627) is the same ratio as 827*:720. *calc -->352 height X 2.35 =827. so i'm thinking there is nothing wrong with megui's sar suggestion. i've never ran into any ar bugs in all my encoding days Last edited by iceborne; 29th January 2006 at 10:22. |
30th January 2006, 11:37 | #46 | Link |
unrecognized user
Join Date: Oct 2005
Location: home of Stella Artois
Posts: 303
|
As I already said, megui calculation of sar is (almost) useless since:
1.it confuses people with the input DAR (which should be 16/9 or 4/3 but instead it actually wants the output DAR (in DigitalDivide's case 2.35)), since rarely will be no cropping. 2.it doesn't actually help much since you already have to calculate DAR yourself so knowing the final resolution you have one extra calculation to make for the SAR (this is what actually megui does). 3.you're better off calculating the SAR or DAR yourself (SAR for input in the x264 config or DAR in mkvmerge).
__________________
zzz |
30th January 2006, 13:07 | #47 | Link |
Moderator
Join Date: Nov 2001
Location: Netherlands
Posts: 6,364
|
I guess i need to install MeGui to see what it is doing, and tell doom9 to correct his gui. The reason is that the way you talk about DAR and SAR in this thread doesn't make any sense. For DAR you should have the choice between 1x1, 4x3 and 16x9. Other choices shouldn't exist. SAR or 'Sample Aspect Ratio' means PAR (at least when talking about AVC streams). Thus a selecting a SAR of 720xsomething when your final encoding should have a PAR of 1:1 doesn't make any sense.
|
30th January 2006, 13:35 | #48 | Link | |
unrecognized user
Join Date: Oct 2005
Location: home of Stella Artois
Posts: 303
|
Quote:
I don't understand why you say only those are possible dars? (it's about output not input, in case of input you are perfectly right). And who said that final PAR has to be 1:1? That's the whole point, no, of anamorphic, that the PAR is not 1:1.
__________________
zzz |
|
30th January 2006, 13:56 | #49 | Link | |
clueless n00b
Join Date: Oct 2001
Location: somewhere over the rainbow
Posts: 10,579
|
Quote:
The ITU people created a real mess with all these terms though. Basically if we had a horizontal stretch factor and that's it, things would be so much simpler. Leave it up to telephony people to create a mess in an area they should've never touched..
__________________
For the web's most comprehensive collection of DVD backup guides go to www.doom9.org |
|
30th January 2006, 14:10 | #50 | Link |
unrecognized user
Join Date: Oct 2005
Location: home of Stella Artois
Posts: 303
|
Yes, you are perfectly right, that's what I've been struggling to say here. There is input (the original dvd) and output (the encoded movie). So the problem in your megui is that for input aspect ratio it actually wants the output one, and from here all the trouble people have understanding how it works. In my opinion this is how megui should work: you put input dar (usually 16/9), you use autocrop (or manual crop), and from that cropping megui should calculate that sar thing. However, megui leaves the same thing for sar no matter what you crop (because basically it requires from the beginning the desired dar). Ouf, I hope I made myself understood this time.
__________________
zzz |
30th January 2006, 14:25 | #51 | Link |
clueless n00b
Join Date: Oct 2001
Location: somewhere over the rainbow
Posts: 10,579
|
it of course comes down to the question of how a playback device handles the DAR flag if the container has one. Is it h_res = v_res * dar ? If so, we need a formula that given the input resolution and dar, and output resolution, calculates the SAR. berrinam wrote the code so I'm not sure how that is being handled, and I have yet to come across a formula anywhere in this forum that would do just that (once again, I never looked at that particular code).
__________________
For the web's most comprehensive collection of DVD backup guides go to www.doom9.org |
30th January 2006, 15:00 | #52 | Link |
unrecognized user
Join Date: Oct 2005
Location: home of Stella Artois
Posts: 303
|
Stupid me! I finally understood what was wrong and what needs to be changed in megui. Actually the SAR doesn't change however you crop, only the DAR is. So why my samples got wrong is because megui doesn't ask what dvd you have: PAL or NTSC, which is crucial. In case of NTSC it always is SAR 1.184 (so one should always put 118:100 in x264) and in case of PAL is always 142:100. That in case of aspect ratio of 16/9. In case of 4/3 is 107:100 for PAL and 88:100 for NTSC. I hope I didn't do any errors in my calculations.
So megui should ask for input DAR (olny 16/9 and 4/3 since I don't think there are original dvd's otherwise), type (PAL or NTSC) and suggest one of the values from above.
__________________
zzz Last edited by Daodan; 30th January 2006 at 18:19. |
30th January 2006, 16:40 | #53 | Link | ||||
Moderator
Join Date: Nov 2001
Location: Netherlands
Posts: 6,364
|
@Doom9,
Quote:
http://www.doom9.org/index.html?/capture/par.html (16.2 examples 2 and 3). See also below: @Daodan, Quote:
Quote:
Quote:
53.333 µs = 720 pixels /13.5 MHz PAR = 576/720 * (4 / 3) * (53.333/52) = 1.094 PAL (width: 704, height 576, DAR 4x3): 52.148 = 704/13.5 PAR = 576/704 * (4 / 3) * (52.148/52) = 1.094 NTSC (width: 720 or 704; height 480, DAR 4x3): PAR = 480/720 * (4 / 3) * (53.3333/52.6555) / (480/486) = 0.9116 NTSC (width: 704, height 480): PAR = ... = 0.9116 etc ... Last edited by Wilbert; 30th January 2006 at 16:43. |
||||
30th January 2006, 17:06 | #54 | Link |
unrecognized user
Join Date: Oct 2005
Location: home of Stella Artois
Posts: 303
|
Well, the results are almost the same as mine (only I didn't take in consideration those µs). The only thing I didn't quite get is what is the deffinition of DAR, in my idea it was display aspect ratio so what I see, so in that case it doesn't matter if it's mpeg 2 or 4 or whatever. Thanks for the link of the guide, I missed that one.
__________________
zzz |
30th January 2006, 17:13 | #55 | Link |
clueless n00b
Join Date: Oct 2001
Location: somewhere over the rainbow
Posts: 10,579
|
@Wilbert: what I cannot find is how given a horizontal and vertical resolution and a PAR I get the playback resolution.. because in the end that's all the player has (especially a PC based player). And software DVD players work the same way... v_res * DAR = h_res.
__________________
For the web's most comprehensive collection of DVD backup guides go to www.doom9.org |
30th January 2006, 18:00 | #56 | Link |
Life's clearer in 4K UHD
Join Date: Jun 2003
Location: Notts, UK
Posts: 12,219
|
Personally I prefer using the following equations: -
Code:
If you require your PAL encode to displayed at 1.33:1 (4:3), use: - 4 576 2304 16 - x --- = ---- lowest dominator -- or 16:15 (or 1.0666666) 3 720 2160 15 If you require your PAL encode to displayed at 1.77:1 (16:9), use: - 16 576 9216 64 -- x --- = ---- lowest dominator -- or 64:45 (or 1.4222222) 9 720 6480 45 If you require your PAL encode to displayed at 1.85:1 (37:20), use: - 37 576 21312 37 -- x --- = ----- lowest dominator -- or 37:25 (or 1.48) 20 720 14400 25 If you require your PAL encode to displayed at 2.35:1 (47:20), use: - 47 576 27072 47 -- x --- = ----- lowest dominator -- or 47:25 (or 1.88) 20 720 14400 25 If you require your PAL encode to displayed at 2.40:1 (12:5), use: - 12 576 6912 48 -- x --- = ---- lowest dominator -- or 48:25 (or 1.92) 5 720 3600 25 Cheers
__________________
| I've been testing hardware media playback devices and software A/V encoders and decoders since 2001 | My Network Layout & A/V Gear |
Last edited by SeeMoreDigital; 30th January 2006 at 18:46. |
30th January 2006, 18:18 | #58 | Link | |
unrecognized user
Join Date: Oct 2005
Location: home of Stella Artois
Posts: 303
|
Quote:
__________________
zzz |
|
30th January 2006, 18:56 | #59 | Link | |
Registered User
Join Date: Jul 2005
Posts: 240
|
Quote:
__________________
Toronto,ON |
|
30th January 2006, 19:17 | #60 | Link | |
Life's clearer in 4K UHD
Join Date: Jun 2003
Location: Notts, UK
Posts: 12,219
|
Quote:
But you might want to give 32:27 (which decimates to 1.1851) a try too
__________________
| I've been testing hardware media playback devices and software A/V encoders and decoders since 2001 | My Network Layout & A/V Gear |
|
|
Thread Tools | Search this Thread |
Display Modes | |
|
|