Why is Vegas external preview so bad?

Sebaz wrote on 5/19/2010, 2:41 PM

I believe that any good NLE should have a flawless external monitor preview without relying on expensive third party cards, as long as the computer has a more or less powerful graphics card with a second HDMI or DVI port, because certainly the capability is there. In Edius, for example, you can choose to use DirectDraw Overlay in the preferences and using the card's Theater Mode you can have a great preview of the footage being played in the NLE, and this includes interlaced footage. It's not a perfect solution, because it forces Windows to go into basic mode and showing the hideous basic interface, but at least it's possible.

In Vegas however, previewing interlaced footage accurately is not possible with the secondary monitor preview that Sony claims in the “Video Editing” section of the Vegas Pro 9 page on Sony's website:

Enhanced Video Monitoring

Well, either this is a case of seriously misleading advertising, or I'm doing something terribly wrong, but I don't think I am, because I have tried several different things to be able to preview interlaced footage properly in my TV set, which is connected to the second DVI output of my ATI HIS Radeon 4850 graphics card, and nothing works. Surely, it displays the footage, and if it were natively progressive footage I wouldn't have a problem with it, but it's 29.97 interlaced footage, and I hate seeing it as progressive when it is not that way. It's as annoying as seeing widescreen movies in 4:3 pan&scan like in the old days.

I would really like to find out what's the cause of this. Perhaps there's nothing that can be done unless SCS fixes it, but perhaps somebody that knows about the inner workings of Vegas, graphics cards and video rendering engines in Windows can figure something out. I have tried several different things and nothing seems to work. No matter what deinterlacing is applied in the project settings, or if deinterlacing is selected in the preview device options, Vegas still displays both fields at the same time on the secondary display, while it displays only one on the monitor window within Vegas' GUI. I'll show you what I'm talking about. In footage I shot last weekend I found this frame that serves well to illustrate this, since I was lifting the tripod with the camera, moving it from one place to another, so it's very shaky footage. In this frame you see big black curtains, partially open so it offers a good contrast to see this problem. I uploaded a few photos rather than screenshots to show properly what I'm talking about. In all these the preview quality is set to Best and Full.

Note: when I first posted this message, I made image tags, and the images would not display, so I changed them to links.

This is the photo I took from the computer monitor, showing the preview area in the Vegas GUI:

http://imgur.com/T0DXb.jpg

And this is the photo I took of the TV set, which is connected to the second output of the graphics card (HIS ATI Radeon 4850, 1 GB of RAM), with deinterlacing unchecked in the preview device options, with the card set to 1920x1080, 60Hz from the ATI control panel:

http://imgur.com/8KNTU.jpg

As you can see, it shows the two fields at the same time (see the ghost effect in the curtains). This wouldn't be a problem if when in motion it would show the fields properly, or at least deinterlace properly, with BOB or some other deinterlacing method, but it doesn't. It shows interlaced video in a weird way that makes it look progressive. You might say, why don't you check the deinterlace option in preview device? Well, I did, and here's what the frame looks like:

http://imgur.com/zg8h1.jpg

Some of you may think that because the card is set to 60Hz (meaning 1080p), but that output is normally set to that and I play all sorts of interlaced content from the computer to the TV set and it displays properly. For example, I watch recorded TV shows from Media Center, all of which come from an interlaced broadcast signal, and some of which are interlaced from the cameras to the final product, such as Saturday Night Live. I also play clips from my AVCHD cameras that are mostly interlaced, and I play them from Media Center, from Media Player Classic, Window Media Player 12 or Splash Lite, and they also display properly in my TV set.

Now, if I switch the signal from the ATI control panel for the TV set from 60 to 30 Hz, the playback in Vegas is a bit smoother, but it's still not interlaced. Playback still makes interlaced video look like weird progressive video. Here's 30 Hz selected in the ATI control panel without “apply deinterlace filter” selected.

http://imgur.com/V0WC3.jpg

And here's 30 Hz with the apply deinterlace filter applied:

http://imgur.com/GUGXh.jpg

As you can see, it barely makes any difference. No matter if the signal selected in the graphics card control panel is 1080p or 1080i, Vegas still shows the two fields at the same time. What the supposed deinterlacing filter does is just remove the comb effect, however, it seems to me that Vegas' external preview module is very poorly written and the deinterlacing filter is just a toy which does nothing more than applying deinterlacing to a video signal that is coming as progressive showing the two fields at the same time. Because as you can see, Vegas shows the two fields at the same time in both 60 and 30 Hz, and with or without the deinterlacing filter applied.

To make things even more interesting, Vegas can show a decent preview that looks kind of like the original, but if you convert the footage to 59.94fps and set the project to the same frame rate. When it's played back, it looks the same to the eye as when 1080i footage is played with the proper field order, and it doesn't show the double field problem, both with the graphics card set to 30 Hz or to 60 Hz. Here's a photo of the TV set with the footage already converted to 59.94 fps progressive, with the graphics card set to 30 Hz for the TV set (it looks the same at 60 Hz):

http://imgur.com/ceXAp.jpg

As you can see, the double field effect is gone.

Just in case you wonder, setting the deinterlace method in the project settings has absolutely no influence in this at all in any of the three choices. All three choices look exactly the same in the second monitor. Also, this is not a matter of which brand of monitor or connection type it may be. This is very easy to test because if, in the Preview Device Preferences you change the display adapter from 2 to 1, making the video preview to show on your main monitor in full screen, it looks just the same as it looks on the TV set, with the double field effect.

I also found out, after I took the photos, that the only way to make the double field effect disappear in the second monitor is setting the preview quality to any of the Draft modes, but the only one that makes sense to select is Draft Full, which is not really full but half size, and it effectively removes one field, so when the cursor is stopped, it may not show the double field effect, but when being played back it still shows the interlaced footage as progressive, obviously because one field is gone.

So I wish I knew exactly what's the problem with this. On one hand, Vegas doesn't seem to connect to any DirectX video rendering engine such as Overlay, VMR 7, VMR 9 or EVR, because any video that goes through those engines can have its picture properties tweaked with the ATI control panel, in the Avivo Video section. See for yourself if you have the Catalyst Control Panel. Select the All Settings tab in the Avivo Video section and try to change brightness, contrast, tint, saturation, or any of the other controls below it, including deinterlacing method. They change video when it's being played from any regular player, but they don't change a thing in the video signal that Vegas sends to the second monitor when external monitor preview is selected. To change the picture settings for that, you have to go to the Color tab in the Desktop Properties section after you selected the second monitor and chose properties.

So the way Vegas sends a signal to the secondary monitor, it seems to me, is absolutely non compliant with DirectX. There are several video players out there, and some are better than others, but one thing they all have in common is that you can always change the picture settings of the video being played with the settings in the Avivo Video section of the ATI control panel (as long as “Use application settings is unchecked, of course”) while you can't do that with Vegas.

But this wouldn't be a terrible problem if it sent a video signal to the external monitor with the fields in the right order, instead of displaying the two at the same time, causing a weird effect that is neither interlaced nor progressive video. It's more like blurry progressive video, caused by displaying the two fields at the same time.

Besides having a very poor monitoring engine for interlaced video, this makes me wonder if the drivers in Vegas for the other preview devices have the same poor quality. I would consider spending $190 in an Intensity Pro card if I knew for sure that it's going to give me perfect interlaced preview, but I don't know for sure and nobody seems to know. I don't want to have to pay for it and the shipping and then waste more money in shipping because I have to return it.

If anybody wants to test this for yourselves, I recompressed a small part of the footage as AVCHD that you can drop in your Vegas timeline and see for yourselves to compare, and you can tell me if you see the same things I see or something different. The file is only 11MB and it's here: http://www.mediafire.com/?dk3jyxjetm0

So, can anybody provide any insight on this? Think of a workaround, a hack, anything? I think at minimum Sony should remove that paragraph from the Vegas information page, because it's very misleading. To say "Next-generation monitoring tools allow full screen timeline playback to LCD and CRT secondary displays via component or DVI connections, with support for scaling, de-interlacing, and color profiles." when it clearly is not like that is pure misleading advertising, and laughable, unless they include in the same paragraph that the monitoring tools are only for progressive video such as 24p or 30p.

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Comments

Sebaz wrote on 5/20/2010, 3:23 PM

Have you tried sending it to someone else's 1080p television? Although from what you described it sounds like Vegas isn't sending out a properly configured signal.

I don't have someone that can come over with an HDTV over here, but it doesn't matter, because like I said, my main monitor is 1080p native, and this double field effect shows in it too, and looks exactly the same as in the Sony 720p TV.

R0cky wrote on 5/21/2010, 11:44 AM

Sending this to my external SD CRT pro monitor I get the double images - it is not displaying properly on my interlaced monitor. I'm using a Canopus ADVC-300 to drive the monitor. I have never been able to get interlaced footage to preview correctly.

If I change my preview to my 2nd 1600x1200 DVI monitor I also get the double images. Checking "deinterlace" just gets rid of the scan lines, I still get the double images.

Rocky

Sebaz wrote on 5/21/2010, 1:34 PM

I have a 720p television as well. It is a Panasonic Plasma. Like all 720p televisions 720p is the only resolution the set can display. If it receives a 1080p or 1080i signal the television converts it to 720p. If it receives a 1080i signal it must downconert and also deinterlace the signal as well.

Also, I would like to reiterate this because it also serves the debunk the theory that this problem might be caused by the TV set being 720p. When I send content that is originated as interlaced, and I send it as a pure interlaced signal to the TV set, the set does the down-sampling and deinterlacing perfectly fine. Like I said, when I connect my AVCHD camcorders through HDMI to the set, the set is getting a 1920x1080 60i signal, and it displays it perfectly. Also I have my blu-ray players normally set to 1080p, so the player does the deinterlacing itself, however, for this purpose I set them both to 1080i and played interlaced sourced content, and it also looks perfect.

So this is clearly not a matter of the TV set, and I'm positive that if I bought a native 1080p Vegas' output would look exactly the same. What I wrote above and the fact that it also shows when I choose my 1080p monitor makes me certain of this.

GlennChan wrote on 5/21/2010, 2:43 PM

Sending this to my external SD CRT pro monitor I get the double images - it is not displaying properly on my interlaced monitor. I'm using a Canopus ADVC-300 to drive the monitor. I have never been able to get interlaced footage to preview correctly.
That *is* correct. You *want* to see both fields without de-interlacing on a CRT.

De-interlacing introduces artifacts (always). Ideally, you want to preview without stuff that introduces artifacts. Unfortunately with most of the non-CRT dispalys, you have to do de-interlacing for moving video.

Also, I would like to reiterate this because it also serves the debunk the theory that this problem might be caused by the TV set being 720p.
That's no way to monitor your signal anyways because scaling from 1080-->720 will introduce artifacts.
http://www.glennchan.info/broadcast-monitors/scaling-artifacts/scaling-artifacts.htm

If you are doing SD work, get a CRT TV to preview on.

JJKizak wrote on 5/21/2010, 4:08 PM

Is there anyone who is selling CRT's anymore?
JJK

Sebaz wrote on 5/21/2010, 4:08 PM

Also, I would like to reiterate this because it also serves the debunk the theory that this problem might be caused by the TV set being 720p.

That may be so, but I would say that the poor quality in which Vegas displays interlaced video using the external preview is far worse to monitor the editing than if it were sending the signal correctly but my TV was downscaling. Besides, I don't know the technical details, but my TV has an excellent downscaler, like I said above, when I bought it there were several native 1080p sets on the sales floor, and this 720p looked better than most of them, both in terms of quality of colors and in sharpness, but without looking like an artificial border enhanced type sharpness. I've had chances to buy 1080p native sets even for a few hundred below what I paid for this one back in 2008, but I've been so happy with this one that I didn't see the point. I will wait until I can buy a top of the line Sony, because then I would see a difference worth paying for.

farss wrote on 5/21/2010, 4:37 PM

"That may be so, but I would say that the poor quality in which Vegas displays interlaced video using the external preview is far worse to monitor the editing than if it were sending the signal correctly but my TV was downscaling"

Finally you get to the core of the problem. Vegas's scaling for External Preview. You can turn that Off. I'd suggest you try doing that and see what if any difference it makes.

Bob.

Rainer wrote on 5/21/2010, 5:38 PM

I think Sebaz means "compared to even the current most basic consumer editing systems", and he's got every right to ask, because it is.

Sebaz wrote on 5/21/2010, 6:24 PM

Finally you get to the core of the problem. Vegas's scaling for External Preview. You can turn that Off. I'd suggest you try doing that and see what if any difference it makes.

No, Vegas is not scaling down to 720p. Vegas outputs in either 1080i or 1080p, depending on which mode I have selected in the ATI control panel. As long as I leave Vegas' external preview to "Current settings" it will not scale anything. I did try however, to select 720p in Vegas while having the card set to 1080p or 1080i, and it made no difference. It changes the card's output to 720p, but it still shows the double field effect.

farss wrote on 5/21/2010, 6:38 PM

Yes, Vegas does something different compared to other NLEs and even hardware boxes although some hardware boxes do the same as Vegas which caused us no end of grief with a large order from The Australian Broadcasting Corporation.

It's pretty common when sending interlaced video and the stream is paused to only send one field to displays. The reason for this is simply to avoid having monitors flickering all over the place. Trust me if you're sitting in master control in front of a wall of flickering monitors you rightly would be screaming.

Vegas does not do this, when you hit pause, Vegas will still send both fields to the display and the display will show both fields. When you actually play out the video of course the eye merges both fields. Comparing what happens when you pause playback with Vegas and what it's doing during playback is going to lead you up the garden path.

This behavior could also confound any display that does a reasonable job of de-interlacing. It takes more than a frame's worth of fields to do an adaptive motion de-interlace.

Bob.

Sebaz wrote on 5/21/2010, 7:18 PM

Bob, I know what you're talking about when you say "It's pretty common when sending interlaced video and the stream is paused to only send one field to displays.", however, this is not the case. There is an option in Edius and in Neo to choose between frame or field for pause, and it works accordingly. If you choose "field" when the cursor is stopped, it will only show one field to avoid the crazy back and forth between the two fields.

This is, however, not the same thing. Vegas does some kind of ridiculous processing in the external preview module, where it actually sends the two fields at the same time instead of one and then the other. The double field effect that I show in those photos with the cursor stopped, it's the same when it's in motion. You see double contours on everything that moves. It looks slightly different if 1080i is selected in the card instead of 1080p. In 1080p the scan lines are more evident, while in 1080i they are smoother, but you still can see the double fields.

I don't know if there's some fancy $1000+ device that will take this mess that Vegas puts out and make it into a decent interlaced signal, but if there is I don't care. I don't even expect Vegas to have a BOB deinterlacer, or any deinterlacer of any kind. I only expect Vegas to output a real 1080i signal, the same as my two blu-ray players, my two AVCHD cameras and the Time Warner Cable piece of junk cable box, all of which send a 1080i signal to the TV set that looks perfect to me.

What I think is that Sony should make some changes urgently in that module so that it works as it should, to send out a real 1080i signal.

Former user wrote on 5/21/2010, 8:03 PM

I don't have HD monitoring, but I see what you are talking about in Vegas.

But if I open the file in VLC, I see the exact same thing. The curtains have the ghosting in VLC as well.

Don't know what that means, but Vegas is showing the same thing as VLC.

Dave T2

farss wrote on 5/21/2010, 8:30 PM

I can confirm that Vegas seems to bypass DirextX. Changes in my nVidia control panel make no difference to Vegas's output to the Secondary Display, only thing that affects that is changes to Vegas own Secondary Display Control. From that changing the De-Interlace, ICM profiles etc do change the outcome. VLC on the other hand is affected by the nVidia control panel.

I can confirm that Vegas does send interlace video correctly down firewire. It does send interlaced SD down a BMD Decklink card to a SD SDI monitor correctly as checked on a rather expensive Sony CRT monitor. I now have access to a system with a Decklink Extreme card in it and can hook up a 17" Panasonic BT-LH1760 monitor that is one of the few monitors that correctly displays interlaced HD. That's going to take me a few days though. If that does work correctly and I have no doubt it will, then I think I can say with a good level of confidence that a BMD Intensity HDMI card will do the same thing, feed interlaced video to your HDTV one field at a time.

Bob.

Sebaz wrote on 5/21/2010, 10:22 PM

Thanks, Bob, it would be good to know, or at least have a notion, that the Intensity card might display real interlaced video.

You can change some of the picture quality settings for the signal being output from Vegas in the graphics card control panel but ironically not where you change those settings for video content, but where you normally change them for the normal Windows desktop. At least it works that way in the ATI control panel. Still, I remember that back when I had a Nvidia card Vegas' external preview looked just as bad for interlaced content.

farss wrote on 5/22/2010, 4:53 AM

The nVidia control panel has a sort of hidden extra for "video". I assume that means for video overlays.
I'm still wanting to know if you've tried using Vegas's own control panel. The interlace, scaling and ICM controls in there certainly change the outcome on the secondary display monitor.

Bob.

Sebaz wrote on 5/22/2010, 10:02 AM

I'm still wanting to know if you've tried using Vegas's own control panel. The interlace, scaling and ICM controls in there certainly change the outcome on the secondary display monitor.

I did, in fact I tried each of the different ICM profiles, even thought ICM profiles really should have no influence in how fields are displayed, but none of them did anything at all for this problem. I also tried selecting custom resolutions, but there's a limit to what you can select. For example, if you set the card to 60 Hz, and you select 1920x1080 (29) or (30), as soon as you click the external preview icon the arrow starts flashing very fast and you get no preview on the TV set. Same thing if the card is set to 30 Hz and you select a custom res. in Vegas of 60 Hz.

Now, even though in the ATI control panel I have a choice of "29i Hz" and "30i Hz", selecting 29 still shows 30i Hz in that list, like you can't select it even though it's available. I don't even know what it means, I don't know if it's supposed to be 29.97 interlaced, and why is there a 29 and 30 Hz choice. Vegas always shows it as (29) even if 30 Hz is selected in the card. I did select 1920x1080 (30) as a custom setting in the Vegas CP and it flashes both screens to black for a split second, and then goes back to normal, except that it seems it really sends a 30 Hz signal to the TV set. Still, the quality of the interlaced preview is just as bad, movement looks blurry, a hybrid between interlaced and progressive video, caused by displaying both fields at the same time.

craftech wrote on 5/22/2010, 11:51 AM

Is there anyone who is selling CRT's anymore?

------------
JVC still sells them.

Here is a place in Secaucus, NJ that sells them. I bought my 15 inch model from them although they don't seem to have them listed anymore. Grazie has the same one. Great monitor.

John

UPDATE: Apparently JVC is phasing them out.

farss wrote on 5/22/2010, 2:31 PM

" even thought ICM profiles really should have no influence in how fields are displayed, but none of them did anything at all for this problem"

Well I'd be pretty surprised too if an ICM profile made any difference to the interlacing.
What about the de-interlace controls in the same control panel?
What about the scaling control in the same control panel?

Bob.

Sebaz wrote on 5/22/2010, 6:36 PM

What about the de-interlace controls in the same control panel?

Also checked those out. Applying deinterlacing makes the motion a little more jumpy, so it's better to leave it off.

As for scaling, I turned it off and on, and it doesn't do anything for this problem.

R0cky wrote on 5/24/2010, 10:57 AM

Glenn, I think I miscommunicated. I did not mean a computer CRT, I meant my Sony video monitor intended for video. Are you saying that should not show interlaced video correctly?

GlennChan wrote on 5/24/2010, 4:30 PM

A CRT (TV or broadcast monitor receiving a video signal) does and should show interlacing correctly. If you can see annoying interlace flicker... e.g. when you pause on a frame of motion and you are seeing both fields jump around like crazy... that is correct.

You need to make sure stuff like that isn't on your final product. You want your monitoring setup to expose that flaw, not hide it.