|
|
| phaeron |
| Posted: Aug 9 2011, 08:43 PM |
 |
|
Virtualdub Developer
Group: Administrator
Posts: 7773
Member No.: 61
Joined: 30-July 02
|
VirtualDub has to work in an environment where the aspect ratio may not be preserved, and as such it would be misleading if it were to display a different AR than what you'd be likely to get. Therefore, the default is still 1:1. You can still choose the display aspect ratio that matches your output medium.
As for the aspect getting whacked in resizing, that's what padding the frame size to 16x16 multiples does. There is no possible way the aspect ratio can be preserved if you are using an option that changes the image size itself. In order to avoid that you would need an alternate mode that either letterboxes or crops or to use an output format for which that is unnecessary.
|
|
| -vdub- |
| Posted: Aug 10 2011, 03:53 PM |
|
|
Advanced Member
Group: Members
Posts: 613
Member No.: 27087
Joined: 24-February 10
|
I don't want to resize any mpeg-2 videos i have. I used resize filters values to show to you the resolution problem with all the filters. That none are able to use the source video resolution and AR for 720x576 with 16:9
I've had a further look at this. Saving to uncompressed avi for tests. The best virtualdub at the moment can output is a 5:4 720x576 with 16:9 framed inside it. The big drawback it now has black bars top and bottom of the video.
Virtualdub any version right now including any exotic custom virtualdub builds. Loaded with mpeg-2 720x576 16:9 (dvd full d1 specification) are all bad maintaining the same input source video resolution and AR for all processing.
Phaeron any plans for virtualdub to have full mpeg-2 internal support. Where this problem would be corrected for all processing including the filters ? |
|
| stephanV |
| Posted: Aug 10 2011, 04:51 PM |
|
|
Spam killer ;)
Group: Moderators
Posts: 4348
Member No.: 8917
Joined: 18-February 04
|
| QUOTE (-vdub- @ Aug 10 2011, 05:53 PM) | | Virtualdub any version right now including any exotic custom virtualdub builds. Loaded with mpeg-2 720x576 16:9 (dvd full d1 specification) are all bad maintaining the same input source video resolution and AR for all processing. |
AVI doesn't have an AR flag so this is no surprise. As long as you don't want to understand what anamoprhic is, there is no point in further discussion.
--------------------
useful links:
VirtualDub, Input plugins and filters, AviSynth, AVI-Mux GUI, AC3ACM by fcchandler, VirtualDub FAQ |
|
| -vdub- |
| Posted: Aug 10 2011, 05:49 PM |
|
|
Advanced Member
Group: Members
Posts: 613
Member No.: 27087
Joined: 24-February 10
|
http://en.wikipedia.org/wiki/Anamorphic_widescreen
So your thinking this video is 4:3 with 16:9 frame inside ?
You do realize all mpeg softwares load using the DAR value which is 720x576 16:9 that i have tried. Using no other AR such as 4:3 or 5:4 or any other.
If load a mpeg-2 video i have into dvd author software and it to use strict dvd D1 spec only (with no compromise settings set). Will author to dvd without issue at using full d1 specification.
You know info tools such mediainfo or g-spot report the video as 720x576 16:9 dvd spec they wouldn't do so if it wasn't so.
Anamorphic is a cop out and is frowned upon by the whole industry i have read. And i can see the reason why. Even older dvd were butchered using it and public outcry put an end to that. Or are all the film studios they still secretly using it for dvd movies!
Got a video that cannot do anything with use anamorphic. Much like what i did with the test using avi with avi sees AR or not. Do the same test using external mpeg encoder will still give same result. And that was the anamorphic test i did. Sure could of done it in a 4:3 frame with 16:9 inside. Same process that i had just tested using the sar 5:4 value instead.
Ok maybe your on the right track as these are from digital tv captures. As are sd would mean have to fit on 4:3 tv screen even if we all mostly have 16:9 tv now. And maybe would account why the sar is 5:4 so means near 1:1 not quite 4:3 but near it. So that all these other softwares are using image aspect ratio or picture aspect ratio DAR to work with instead of SAR or PAR to load and process with.
Still doesn't mean virtualdub or a mpeg-2 plugin code couldn't be modified to to do so also. Like all the other softwares out there have done to work with these mpeg-2 which also are same with new dvd films. That said i only mention dvd to show what i have is the same. I don't bother with retail dvd haven't the time to do so.
Virtualdub doesn't see the mpeg-2 video correctly. There must be code around to implement this into virtualdub since every other software is doing this correctly for mpeg-2. Or maybe developers learned the easy way to do this and use DAR since is always holds the correct information for mpeg-2 videos. |
|
| stephanV |
| Posted: Aug 11 2011, 05:04 PM |
|
|
Spam killer ;)
Group: Moderators
Posts: 4348
Member No.: 8917
Joined: 18-February 04
|
| QUOTE | Anamorphic is a cop out and is frowned upon by the whole industry i have read. And i can see the reason why. Even older dvd were butchered using it and public outcry put an end to that. Or are all the film studios they still secretly using it for dvd movies!
|
There are no non-anamorphic DVDs (in the broad sense). DVD is based on a analog standard where samples (the equavalent of pixels on a computer) are non-square. 720x576 will only look correct on an analog television. On a display with square pixels (such as all computer displays are) these videos are resized by the player (say to 1024x576) to look correct.
What you are asking for is to let VirtualDub also automatically do this resizing, but this would either be an unwanted operation when the resizing is also done on saving, or it would be lying to the user when it is only used for display. AVI doesn't have an AR flag so what you see is not what you get then.
So no, your request does not make sense.
--------------------
useful links:
VirtualDub, Input plugins and filters, AviSynth, AVI-Mux GUI, AC3ACM by fcchandler, VirtualDub FAQ |
|
| -vdub- |
| Posted: Aug 12 2011, 02:57 AM |
|
|
Advanced Member
Group: Members
Posts: 613
Member No.: 27087
Joined: 24-February 10
|
As said all mpeg-2 softwares i have tried. Do load these mpeg-2 video correctly and able to display, process and save using the DAR image/picture aspect ratio.
Which could mean virtualdub could do the same also. For me its not about pixel square or not, anamorphic or any other. Its about using the DAR values correctly to display, process and save. Also maybe could even use the MAR (movie aspect ratio) which i understand for mpeg-2 uses also the DAR values. So if all these softwares can use it so also could virtualdub with code change or code addition.
| QUOTE | Directshow Input Driver
Version 0.9:
Fixed the source aspect ratio -- it was sending DAR as PAR. |
After dar bug fixed that has been posted here DirectShow Input Driver thread (posted: Aug 10 2011). Maybe will correct this problem.
|
|
| stephanV |
| Posted: Aug 12 2011, 05:07 AM |
|
|
Spam killer ;)
Group: Moderators
Posts: 4348
Member No.: 8917
Joined: 18-February 04
|
| QUOTE (-vdub- @ Aug 12 2011, 04:57 AM) | | As said all mpeg-2 softwares i have tried. Do load these mpeg-2 video correctly and able to display, process and save using the DAR image/picture aspect ratio. |
For the third time, you *cannot* save an AR flag in AVI. Yes you can do this in MPG, but VirtualDub only supports exporting to this format through external encoders, over which it has no control.
The problem here is not displaying the video correctly, that is easy. The problem is that by displaying something in a certain way a user also expects something, and living up to these expectations is what VirtualDub cannot do without potentially breaking the video.
What you see you should always be what you get. If some users do not *understand* what they see, is a whole different issue. And it can't be fixed with code.
--------------------
useful links:
VirtualDub, Input plugins and filters, AviSynth, AVI-Mux GUI, AC3ACM by fcchandler, VirtualDub FAQ |
|
| -vdub- |
| Posted: Aug 12 2011, 06:09 AM |
|
|
Advanced Member
Group: Members
Posts: 613
Member No.: 27087
Joined: 24-February 10
|
All softwares was implyied as 'all of the mpeg-2 softwares i tried'.
So i loaded a mpeg-2 to videoredo to change the par flag. I save it changing the header to 2:21.1 g-spot show par changed to 2:21.1
Loaded video into videoredo and still the same problem. So confirmed that SAR is the values that virtualdub is using.
Is there a small free tool that can change the SAR value. For mpeg-2 video without encoding or transcoding ? |
|
| -vdub- |
| Posted: Aug 15 2011, 04:13 PM |
|
|
Advanced Member
Group: Members
Posts: 613
Member No.: 27087
Joined: 24-February 10
|
This video always uses the sar value of 5:4 with virtualdub maybe meaning 1:1 is the sar value or first value seen in mpeg video.
I never intend to resize these mpeg2 videos. But maybe i can work with them at 1024x576 using raytheOn FFMpeg Input filter. So when i load the video all displays and all filters are 1024x576 16:9. I could then do video filter work and within the same process resize back to 720x576 and 5:4 sar will return. Output using external encoders for mpeg2 transcode.
I am still concerned about the warning that VDMod_Resize filter shows Interlace (not recommended for enlarging). My thoughts for deinterlace has been not to deintelace let the tv hardware do it as it is designed to do. Also is better than any software deinterlacer with these videos.
I did a big search and is still no clearer what the problem would be for enlarging interlace video to 1024x576 and back within the same transcode process. Except something to do with vertical resolution been smaller than the horizontal resolution, what is all that about ?
Any other known problems also when enlarging interlaced video resolution ?
Does virtualdub use an internal frame server to process video using raw avi and that this avi is 1:1 square pixel shape ?
1:1 pixel from Phaerons post above.
Also 16x16 multiples what is the correct one to use for 1024x576 16:9 and 5:4. which i may need to use for processing or resize back to 720x576 5:4 ?
Or is the 16x16 referring to picture quality quantization compression matrices intra | non-intra that each 8x8 together maybe represent the 16x16 ?
|
|
| stephanV |
| Posted: Aug 15 2011, 06:59 PM |
|
|
Spam killer ;)
Group: Moderators
Posts: 4348
Member No.: 8917
Joined: 18-February 04
|
| QUOTE (-vdub- @ Aug 15 2011, 06:13 PM) | | I never intend to resize these mpeg2 videos. |
And there we get to the whole point. The thing you are demanding here is actually that VirtualDub should resize the video. You don't want that, so VirtualDub is already doing exactly what you want.
--------------------
useful links:
VirtualDub, Input plugins and filters, AviSynth, AVI-Mux GUI, AC3ACM by fcchandler, VirtualDub FAQ |
|
| -vdub- |
| Posted: Aug 15 2011, 11:04 PM |
|
|
Advanced Member
Group: Members
Posts: 613
Member No.: 27087
Joined: 24-February 10
|
Only doing so if i use FFmpeg Input Driver with option selected so it does so. Otherwise it displays and edits as 720x576 5:4 ar. Which is is wrong pixel shape for the 16:9 resolution.
If you read on the next sentence goes on to say.
| QUOTE | | But maybe i can work with them at 1024x576 using raytheOn FFMpeg Input filter. |
Meaning if i need to process the video that i will need to use 1024x576. The post was written to learn more about the pitfalls of doing this. The reason for asking those questions in the post.
|
|
| stephanV |
| Posted: Aug 16 2011, 04:49 AM |
|
|
Spam killer ;)
Group: Moderators
Posts: 4348
Member No.: 8917
Joined: 18-February 04
|
| QUOTE (-vdub- @ Aug 16 2011, 01:04 AM) | | Only doing so if i use FFmpeg Input Driver with option selected so it does so. Otherwise it displays and edits as 720x576 5:4 ar. Which is is wrong pixel shape for the 16:9 resolution. |
The pixel shape is a flag. Digital pixels have whatever shape you want them to be. It's irrelevant for filtering.
--------------------
useful links:
VirtualDub, Input plugins and filters, AviSynth, AVI-Mux GUI, AC3ACM by fcchandler, VirtualDub FAQ |
|
| -vdub- |
| Posted: Aug 16 2011, 04:19 PM |
|
|
Advanced Member
Group: Members
Posts: 613
Member No.: 27087
Joined: 24-February 10
|
Your replies so far haven't exactly answered any questions from the initial post. That I posted Aug 15 2011, 04:13 PM |
|
| -vdub- |
| Posted: Aug 16 2011, 04:31 PM |
|
|
Advanced Member
Group: Members
Posts: 613
Member No.: 27087
Joined: 24-February 10
|
<> |
|
| stephanV |
| Posted: Aug 16 2011, 04:54 PM |
|
|
Spam killer ;)
Group: Moderators
Posts: 4348
Member No.: 8917
Joined: 18-February 04
|
The initial question does not make any sense. 1. You don't need to resize. 2. For filtering the pixel shape is irrelevant.
--------------------
useful links:
VirtualDub, Input plugins and filters, AviSynth, AVI-Mux GUI, AC3ACM by fcchandler, VirtualDub FAQ |
|
