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 > Capturing and Editing Video > VirtualDub, VDubMod & AviDemux

Reply
 
Thread Tools Search this Thread Display Modes
Old 17th October 2018, 10:40   #681  |  Link
shekh
Registered User
 
Join Date: Mar 2015
Posts: 706
From the screenshot it seems Sony is using bilinear downsampling for 444->422, this blends max 2 neighbor pixels as opposed to summed area.
I changed various interpolation options until I got very similar picture.
For 442->444 it is still bilinear upsampling, no changes.

Last edited by shekh; 17th October 2018 at 10:42.
shekh is offline   Reply With Quote
Old 17th October 2018, 14:58   #682  |  Link
WorBry
Registered User
 
Join Date: Jan 2004
Location: Here, there and everywhere
Posts: 1,181
Thanks again Skekh,

Just to be clear about VDub2:

Quote:
Originally Posted by shekh View Post
Checked what is going on with chroma,
444 -> 422: each pixel is convolved with kernel 0.25, 0.5, 0.25
As I understand this creates some blurring.

422 -> 444: odd pixel is copied as is, even pixel is blended from two neighbor source pixels
This is simple.
So is the 422 > 444 in VDub2 (by definition) Nearest Neighbor (Point) up-sampling, which is how I first interpreted your description, or Bilinear upsampling ?

Quote:
Originally Posted by WorBry View Post
So, if I understand correctly, its 'nearest neighbour' (point) up-sampling and it's the convolution averaged chroma sub-sampling that brings about the separation of the R/B and G channel plots on the Resolve Parade scope, which manifests as blur ?



Up-sampled in that example to r210, because Resolve wont import v410
As regards Resolve; actually prior to 15.1.1 version update, the v210 'round-trip/pass-through' behavior (using the 'Checker-422' clip) was different



The change in behavior seen in 15.1.1 came in response to concern (from BMD forum members) about the quality of the export 422 sub-sampling:



Which is when it became apparent that the 'new' behavior bore a striking similarity to that seen in VDub2 for 422 > 444 > 422.

In fact, referring back to the series I posted earlier....



....when I ran quality metrics (FFMPEG) on the matched v210 exports from the Resolve and VDub2 series, the SSIM scores were 1.000000 (lossless) for Luma and UV chroma.
__________________
Nostalgia's not what it used to be

Last edited by WorBry; 17th October 2018 at 16:08.
WorBry is offline   Reply With Quote
Old 17th October 2018, 15:50   #683  |  Link
shekh
Registered User
 
Join Date: Mar 2015
Posts: 706
Quote:
Originally Posted by WorBry View Post
So is the 422 > 444 in VDub2 (by definition) Nearest Neighbor (Point) up-sampling, which is how I first interpreted your description, or Bilinear upsampling ?
Bilinear. Even sample is centered so it is not blended but odd sample is blended.
__________________
VirtualDub2
shekh is offline   Reply With Quote
Old 17th October 2018, 16:10   #684  |  Link
WorBry
Registered User
 
Join Date: Jan 2004
Location: Here, there and everywhere
Posts: 1,181
Thank-you Shekh.

Quote:
Originally Posted by poisondeathray View Post
That DNxHR result is completely unexpected and unacceptable. Something is up

And I'm getting similar results with Adobe's DNxHR/DNxHD implementation , also on encoding/decoding. It looks like some sort of DCT compression issues.
FWIW - Here's the Checker-444 clip and an FFMPEG DNxHR_444 (10bit) transcode loaded into VDub2 and examined on Color Tools 1.4 videoscopes:



Same pattern as seen on the Resolve scopes.
__________________
Nostalgia's not what it used to be

Last edited by WorBry; 17th October 2018 at 19:27.
WorBry is offline   Reply With Quote
Old 17th October 2018, 19:21   #685  |  Link
Morku
Registered User
 
Join Date: Jul 2012
Posts: 161
Hi, I want to capture avi with an usb grabber which works without issue, but... the preview image not work.

Weirdly it worked at the first attempt. I go to capture mode and Video was set to Overlay and it was previewed. Then I opened Capture settings and the preview image got stuck... So I closed, reopen VirtualDub -> no more preview.
So I changed "Display with Filters" and got a (distorted) preview, but it worked... also only for a moment. Next day, now every preview not show an image
So I deleted the VirtualDub regedit settings to start from beginning, but no chance, I don't get a preview.

The only way to get a preview is, when I open the Cropping dialog.
So I wanted to cheat VirtualDub and start a recording during Cropping dialog is open. Of course, it doesn't work. It also not work to open Cropping dialog when it is in capture mode.
Even open a second VirtualDub instance not work, because the USB grabber is taken of the first VirtualDub...

Any idea how I get the preview back and what made the preview vanish. Many thank you for the idea.

The Device itself is Dazzle DVC100 Video Device (DirectShow)

Capturing the videosource just works, but without the preview I can't see if there is content.
Morku is offline   Reply With Quote
Old 17th October 2018, 20:04   #686  |  Link
shekh
Registered User
 
Join Date: Mar 2015
Posts: 706
Morku, do you see anything in the log (Capture->Log)? What is capture format?
It is interesting that crop dialog can show preview. Maybe because it does not use audio. Try to disable it (previewing audio).
__________________
VirtualDub2
shekh is offline   Reply With Quote
Old 17th October 2018, 20:19   #687  |  Link
Morku
Registered User
 
Join Date: Jul 2012
Posts: 161
Yes, there is an error:
[i] CapDShow: loading video filter state: (error code: 800704df,
ERROR_ALREADY_INITIALIZED)

[i] CapDShow: loading audio filter state: (error code: 800704df,
ERROR_ALREADY_INITIALIZED)

[i] Connected to capture device: Dazzle DVC100 Video Device (DirectShow)

Audio preview is not enabled, only that audio capture is enabled and to show Volume meter.
I switched the Audio device and for now, I have a preview with "Display with Filters". I reopen VDub, but with Audio "0 Line (DVC100)".
Still, I can't say if there is a relation to the audio setting.
Overlay preview still not work at all, no matter which audiosetting I pick (or disable).
Morku is offline   Reply With Quote
Old 17th October 2018, 20:20   #688  |  Link
richardpl
Registered User
 
Join Date: Jan 2012
Posts: 97
Quote:
Originally Posted by WorBry View Post
Thank-you Shekh.



FWIW - Here's the Checker-444 clip and an FFMPEG DNxHR_444 (10bit) transcode loaded into VDub2 and examined on Color Tools 1.4 videoscopes:



Same pattern as seen on the Resolve scopes.
What's point in using different scopes? Avid encodes behaves in similar way.

I could show you ffmpeg scopes, but that would be totally pointless.
richardpl is offline   Reply With Quote
Old 17th October 2018, 21:04   #689  |  Link
shekh
Registered User
 
Join Date: Mar 2015
Posts: 706
Quote:
Originally Posted by Morku View Post
Yes, there is an error:
[i] CapDShow: loading video filter state: (error code: 800704df,
ERROR_ALREADY_INITIALIZED)

[i] CapDShow: loading audio filter state: (error code: 800704df,
ERROR_ALREADY_INITIALIZED)

[i] Connected to capture device: Dazzle DVC100 Video Device (DirectShow)
Unfortunately these are not real errors. It means part of settings are not restored but this is irrelevant to the preview problem.
Also there is nothing special in the cropping dialog. I'm suspecting everything actually works but the window which should hold preview somehow disappeared. Can you see any preview with different device (usb camera?), or video file (emulation), or UScreenCapture?

Edit: I misunderstood, do you now have stable preview using mode "display with filters"? Overlay mechanism is a bit vague to me, I consider it may work or not depending on some driver/system weirdness.
__________________
VirtualDub2

Last edited by shekh; 17th October 2018 at 21:08.
shekh is offline   Reply With Quote
Old 17th October 2018, 21:46   #690  |  Link
WorBry
Registered User
 
Join Date: Jan 2004
Location: Here, there and everywhere
Posts: 1,181
Quote:
Originally Posted by richardpl View Post
What's point in using different scopes? Avid encodes behaves in similar way.
Purely as further validation that the issue is not with Resolve's decoder/scopes. Plus this is VirtualDub2 thread.

Quote:
Originally Posted by poisondeathray View Post
Since ffmpeg/avid/resolve all look bad in resolve, it might be as simple as a bad decoder version in resolve
Anything useful to add yourself ?
__________________
Nostalgia's not what it used to be

Last edited by WorBry; 17th October 2018 at 22:07.
WorBry is offline   Reply With Quote
Old 17th October 2018, 21:55   #691  |  Link
poisondeathray
Registered User
 
Join Date: Sep 2007
Posts: 3,982
Quote:
Originally Posted by WorBry View Post
Anything useful to add yourself ?
No, just the Adobe tests - confirmed it's the same for DNxHD/DNxHR encode /decode

If richardpl's comment "Avid encodes behaves in similar way" means avid encode and re-import behaves the same way, that pretty much means that's how it is - since it's avid's own official encoder and decoder.



Rant: Historically, it's the worst (near lossless) intermediate ever. Enormous issues and inconsistencies with levels across applications - all over the place. You almost needed to use Avid MC to ensure consistency . Performance isn't even that great decoding wise (FPS), and quality wise it's almost always lower in all tests , PSNR, SSIM or eyeball. This noise on the pattern test doesn't help either
poisondeathray is offline   Reply With Quote
Old 17th October 2018, 22:06   #692  |  Link
WorBry
Registered User
 
Join Date: Jan 2004
Location: Here, there and everywhere
Posts: 1,181
Quote:
Originally Posted by WorBry View Post
Anything useful to add yourself ?
I was responding to richardpl there.

Quote:
Originally Posted by poisondeathray View Post
If richardpl's comment "Avid encodes behaves in similar way" means avid encode and re-import behaves the same way, that pretty much means that's how it is - since it's avid's own official encoder and decoder.
I wasn't sure what he meant there. Anyway I went ahead and re-installed Media Composer to clear that one up. Still can't figure if/how it's possible to export DNxHR_444 from a 1080p project, but the re-imported DNxHD_444 export of the Checkers-444 clip shows the same 'degraded' pattern on the Media Composer scopes.

Do I need to post some scope images or would that be "pointless" ?

Quote:
Originally Posted by poisondeathray View Post
Rant: Historically, it's the worst (near lossless) intermediate ever. Enormous issues and inconsistencies with levels across applications - all over the place. You almost needed to use Avid MC to ensure consistency . Performance isn't even that great decoding wise (FPS), and quality wise it's almost always lower in all tests , PSNR, SSIM or eyeball. This noise on the pattern test doesn't help either
I'd read (same reference that mentioned the intentional 'blur') that DNxHR_444 was designed to be 'visually' (assumed psychovisually) lossless, whereas ProRes_444 tries to get closer to 'mathematically' lossless. But I've seen a number of anecdotal reports complaining about block artifacts especially.

Pity as its really the only 444 export option in Resolve on Windows. Cineform RGB 12bit exports at Filmscan 1/2 quality are too large for my purposes.
__________________
Nostalgia's not what it used to be

Last edited by WorBry; 18th October 2018 at 00:43.
WorBry is offline   Reply With Quote
Old 17th October 2018, 22:21   #693  |  Link
poisondeathray
Registered User
 
Join Date: Sep 2007
Posts: 3,982
Quote:
Originally Posted by WorBry View Post
I wasn't sure what he meant there. Anyway I went ahead and re-installed Media Composer to clear that one up. Still can't figure if/how it's possible to export DNxHR_444 from a 1080p project, but the re-imported DNxHD_444 export of the Checkers-444 clip shows the same 'degraded' pattern on the Media Composer scopes.

Do I need to post some scope images or would that be "pointless' ?
Personally I think it's pointless . That's confirmation enough for me
poisondeathray is offline   Reply With Quote
Old 17th October 2018, 23:22   #694  |  Link
Morku
Registered User
 
Join Date: Jul 2012
Posts: 161
@shekh
I tried my Logitech 9000 Pro. Shown as "Logitech QuickCam Pro 9000 (DirectShow)".
It is the same thing. Overlay not show anything. Display with Filters may work, but in a strange way (but always when I start capturing, the Preview is in that mode fine).

Device Screen capture works without issue. I always get a preview (Overlay, Preview and Display with Filters).

Than there is Microsoft WDM Image Capture (Win32) (VFW) -> it also always work (Overlay is greyed out, no problems with Preview and Display with Filters). This mode anyway is shaky and also the recordings aren't correct.

So the only relation I see between my Webcam and USB grabber is DirectShow. Anything I could try here?
Morku is offline   Reply With Quote
Old 18th October 2018, 00:22   #695  |  Link
shekh
Registered User
 
Join Date: Mar 2015
Posts: 706
Quote:
Originally Posted by Morku View Post
Display with Filters may work, but in a strange way
And when you open cropping dialog, it is normal (not strange)? Btw how it is in strange way, may a screenshot show this?
I also received a somehow related ticket https://sourceforge.net/p/vdfiltermod/tickets/186/
Do you have Nvidia drivers?
__________________
VirtualDub2
shekh is offline   Reply With Quote
Old 18th October 2018, 00:50   #696  |  Link
wonkey_monkey
Formerly davidh*****
 
wonkey_monkey's Avatar
 
Join Date: Jan 2004
Posts: 1,840
When directly opening an MKV (H.264/AVC) what does [+] mean when shown as the frame type (instead of [I], [B], [K], [P], etc)? Does it indicate a problem reading the file?

(also what's the difference between [I] and [K]?)
__________________
My AviSynth filters / I'm the Doctor
wonkey_monkey is offline   Reply With Quote
Old 18th October 2018, 01:14   #697  |  Link
shekh
Registered User
 
Join Date: Mar 2015
Posts: 706
Quote:
Originally Posted by davidhorman View Post
When directly opening an MKV (H.264/AVC) what does [+] mean when shown as the frame type (instead of [I], [B], [K], [P], etc)? Does it indicate a problem reading the file?

(also what's the difference between [I] and [K]?)
[+] is a "no frame", frame is expected at this place, but when actually decoding ffmpeg does not report matching timestamp.
some possible reasons:
wrong framerate - you would see + at repeating intervals
or variable framerate,
wrong duration,
also possible corrupt file

If you think it is wrong maybe I need to look at sample.

[I] is frame type as reported by ffmpeg, [K] is frame which I assume is keyframe (IDR) because it is marked as key in the index table.
However I noticed weirdness about it. index in ffmpeg is in damn dts units/order which is slightly off real frames even in best case.
__________________
VirtualDub2
shekh is offline   Reply With Quote
Old 18th October 2018, 05:39   #698  |  Link
WorBry
Registered User
 
Join Date: Jan 2004
Location: Here, there and everywhere
Posts: 1,181
@ poisondeathray

Quote:
Originally Posted by poisondeathray View Post
@WorBry - if you have serially changing each generation , it suggests some interpolation going on, probably bicubic. If you have blocky sharp color borders and preserved same up/down over each generation, it can only be nearest neighbor . You can verify this by controlling the algorithm in say vapoursynth or avisynth or ffmpeg , export either v210 or v410 and check . You can check the RGB conversion algorithm this way too
Just as a post script. I've been doing just that with the 'Checkers-422' clip in AVISynth+ - converting to 10bit YUV444 and back to 10bit YUV422 using different chroma-sampler combinations and then (via p210 output) encoding to v210 in VDub2. Based on the pattern of results seen on the Resolve scopes and comparative quality metrics (SSIM and PSNR) I'm convinced that Resolve applies Bilinear chroma up-sampling and down-sampling when v210 is 'pass-through' exported to v210. Any other 'chroma-sampler' combination would produce measurably different results.

There I'm done. Sorry to interrupt more important VDub2 business.
__________________
Nostalgia's not what it used to be

Last edited by WorBry; 18th October 2018 at 05:51.
WorBry is offline   Reply With Quote
Old 18th October 2018, 11:24   #699  |  Link
wonkey_monkey
Formerly davidh*****
 
wonkey_monkey's Avatar
 
Join Date: Jan 2004
Posts: 1,840
Quote:
Originally Posted by shekh View Post
[+] is a "no frame", frame is expected at this place, but when actually decoding ffmpeg does not report matching timestamp.
some possible reasons:
wrong framerate - you would see + at repeating intervals
or variable framerate,
wrong duration,
also possible corrupt file

If you think it is wrong maybe I need to look at sample.
It's a DVB-S recording from BBC One HD, remuxed using MakeMKV because FFMPEG has major problems with it in its raw state, and it only shows [+] when it gets to the end credits, which are interlaced (the rest of it is progressive, or progressive-in-interlaced or however it's done).

DGIndexNV/dgsource has no such trouble.

Here's a sample, including the final (progressive) scene which plays back fine. The sample is a Trimmed TS output from DGIndexNV, rather than the full remuxed file I mentioned above:

http://horman.net/credits.ts

VLC and MPC-HC both have the same problem, causing stuttering. Windows Media Player is okay. I'm guessing it's purely an FFMPEG problem.
__________________
My AviSynth filters / I'm the Doctor
wonkey_monkey is offline   Reply With Quote
Old 18th October 2018, 15:36   #700  |  Link
shekh
Registered User
 
Join Date: Mar 2015
Posts: 706
I did not study ts internals. It appears this format typically needs full parsing to understand frames timing (which I assume is what DGIndex is doing).
Also the magic of switching progressive and interlacing.. ffmpeg provides some info when decoding but I'm not sure what could I do with it.
__________________
VirtualDub2
shekh is offline   Reply With Quote
Reply

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 06:26.


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