Cropping doubts

[John Rofrano]

I would change your project properties to match your output properties. In your case that would be PAL DV (720×576, 25.000 fps). Then open Pan/Crop on each event, right-click the frame and select Match Output Aspect. You’e done. You’ll have a perfectly cropped image and you can move the crop if needed to reframe the shot.

~jr

http://www.johnrofrano.com
http://www.vasst.com

[Fabio Mereghetti]

mmm…

I created a new project with Widescreen DVD PAL settings.
Then I imported an HDV clip (1440×1080 50i) into the timeline.
I selected the event and then opened the pan/crop window.
After I right clicked on the frame, in the crop window, and chose
“match output aspect”, I can see the crop area has become 1440×1054.4.
In the preview window, set at “Best”, I can now see two small black lines at top and bottom of the frame. I unchecked both “Mantain aspect ratio” and “Stretch to fill the frame.

Shouldn’t the crop area size become 720×576 as the project properties video settings?

What am I doing wrong?

Thanks.

[John Rofrano]

OK, now I’m confused. In your original post you said:

Let’s say all the info is in the middle of the frame and I would be happy to keep the middle rectangle

Which immediately made me think that you were delivering in 4:3 otherwise what does the “middle rectangle” refer to.

But now I see you also said:

Final output will have to be standard Wide DVD.

So you shot in wide screen HD and you are delivering in widescreen PAL DV which should pose a small pillarbox problem not letterbox.

So let’s go over this slowly:

I created a new project with Widescreen DVD PAL settings. Then I imported an HDV clip (1440×1080 50i) into the timeline.

At this point what do you see? When I start a PAL DV Widescreen project and I drop HDV 1440×1080 PAR 1.3333 footage into it I see two black pillarboxes on either side of the preview. Is that what you see?

I selected the event and then opened the pan/crop window. After I right clicked on the frame, in the crop window, and chose “match output aspect”, I can see the crop area has become 1440×1054.4.

That’s exactly what I see and it makes perfect sense when you do the math. HDV is 16:9 and PAL Widescreen is slightly wider that 16:9 (1049×576 is wider than 1024×576 which is 16:9).

In the preview window, set at “Best”, I can now see two small black lines at top and bottom of the frame.

I can’t imagine how that happened. What version of Vegas are you using. If Vegas Pro 9.0, check your project properties and see if “Adjust source media to better match project or render settings” is checked. This will change what you see.

I unchecked both “Mantain aspect ratio” and “Stretch to fill the frame.

I would keep them checked if you want the aspect to stay correct. Otherwise you may get an odd sized crop.

~jr

http://www.johnrofrano.com
http://www.vasst.com

[Fabio Mereghetti]

First of all, thank you for the time you’re spending to help me. Second, double thank you for your taking me “by hand” through the little misteries of digital video standards.

Now, let’s dive into the matter…

I created a new project with Widescreen DVD PAL settings. Then I imported an HDV clip (1440×1080 50i) into the timeline.

At this point what do you see? When I start a PAL DV Widescreen project and I drop HDV 1440×1080 PAR 1.3333 footage into it I see two black pillarboxes on either side of the preview. Is that what you see?

Correct. Provided that “Scale video to fit preview window” is ON (right clicking on the preview window).
Let me mention here also that if “Simulate device aspect ratio” setting is OFF the content of the frame is vertically stretched (a circle will look as a vertical ellipses). I mention this because only very recently I started to know that each format has its own “pixel shape”, has,n it?.
With different preview settings we see different “Display” dimensions:
with “Simulate…” OFF and “Scale…” ON circle=ellipses and dims 686×549
with “Simulate…” OFF and “Scale…” OFF circle=ellipses and dims 720×576.
with “Simulate…” ON and “Scale…” OFF circle=circle and dims 1049×576.
With “Simulate…” ON and “Scale…” ON, circle=circle and dims 781×429.

Is all that correct?

I selected the event and then opened the pan/crop window. After I right clicked on the frame, in the crop window, and chose “match output aspect”, I can see the crop area has become 1440×1054.4.

That’s exactly what I see and it makes perfect sense when you do the math. HDV is 16:9 and PAL Widescreen is slightly wider that 16:9 (1049×576 is wider than 1024×576 which is 16:9).

Sorry, I was expecting to see a cropping area with the same dimensions of the output. Now I understand that it matches just the output aspect ratio.
While we are here, let me clear one doubt.
As we’ve seen above, the same video can be said to have different dimensions and so aspect ratios, according to different project and preview settings (not to mention rendering ones): if I want to crop “by numbers” (instead of “by contents”), which one I have to take as reference?

In the preview window, set at “Best”, I can now see two small black lines at top and bottom of the frame.

I can’t imagine how that happened.

I unchecked both “Mantain aspect ratio” and “Stretch to fill frame” in the crop dialog.

Before going on to talk more of cropping, I have another main concern and it is about the Preview window and the “Video preview in external monitor” feature.
I would be happy with just the Preview window but, if I understand correctly, there is no color management there so you see very different color than the ones you’ll get in the ouput. So I need to use the color managed external monitor preview, right?

I’m working on a 1600×1200 LCD monitor and I don’t have any other output devices so I’m using the “Windows secondary display” as output device. Now it is set like that:
Display adapter = 1600×1200 (60) – no othere choices
Display mode = Pick custom settings (1600×1200 (60) – no 1440×1080 settings in the list, here
Scale output to fit display = OFF – 1600×1200 is bigger than 1440×1080 so no scaling required, right?
Apply deinterlace filter = no
Use color management = ON – I use a custom profile

With project settings like HDV 1440×1080 PAR 1.3333, the preview on the external monitor is always using all the 1600 pixels for the width: do I have to think that 1440×1080 is always rendered as 1920×1080ù’ (as the “Display” dims shows if I set the “Scale video to fit preview window” at OFF) If yes: why? And then: how this will influence the cropping?

Thanks again.

P.S.
If you think this subject, and the way we are treating it on this thread, could be useful for other people too, I’ll be glad to help taking it on a more general path along the way.

Fabio

P.P.S
Isn,t there a “Quote” button in this forum? I see only “Replay”, “Like” etc…

[John Rofrano]

With different preview settings we see different “Display” dimensions:
with “Simulate…” OFF and “Scale…” ON circle=ellipses and dims 686×549
with “Simulate…” OFF and “Scale…” OFF circle=ellipses and dims 720×576.
with “Simulate…” ON and “Scale…” OFF circle=circle and dims 1049×576.
With “Simulate…” ON and “Scale…” ON, circle=circle and dims 781×429.

Is all that correct?

Yea, it gets confusing. Scaling just affects if the video will fill the preview or not. It does not affect the aspect. Simulate only affects non-square pixel aspect ratios by making them square again. You should always have Simulate on and it’s your own preference whether to have scale on or not. It really doesn’t affect anything critical.

Sorry, I was expecting to see a cropping area with the same dimensions of the output. Now I understand that it matches just the output aspect ratio.

Exactly! You got it now. This is all about ratios of width to height regardless of resolution.

As we’ve seen above, the same video can be said to have different dimensions and so aspect ratios, according to different project and preview settings (not to mention rendering ones): if I want to crop “by numbers” (instead of “by contents”), which one I have to take as reference?

There are three aspect ratios. The ratio of your Project, your Media, and your Render. If you want no surprises when you render, you should keep your Project and Render aspect the same. Then crop your Media to the same aspect as your render (output).

So let’s do the math so you can “crop by numbers” 😉

PAL Widescreen is 720 x 576 PAR 1.4568. That means that each horizontal pixel represents 1.4568 pixels in the image. So we must multiply 720 by 1.4568 to get the dimension in square pixels.

720 x 1.4568 = 1048.896

Rounding to 1049 (because you can’t “physically” have a fractional pixel) we see that PAL Widescreen is 1049×576 PAR 1.0.

But what is the ratio? If we divide 1048.896 by 576 we see that the ratio of width to height is 1.821 to 1 (expressed as 1.821:1).

We are now ready to crop “by numbers”. Remember that 1440×1080 has a PAR of 1.3333. Before you can do any math you must normalize it to PAR 1.0 so 1440 x 1.3333 = 1920 (well… 1919.952 but that rounds to 1920). So your video is 1920×1080 PAR 1.0. If we keep 1920 as the widest dimension and want to crop the 1080 to match the aspect of PAL Widescreen we divide 1920 by 1.821 and get 1054.3657. This is why you saw the crop area had become 1440×1054.4 in Vegas. 🙂

If there is a time when you want to keep the height and crop the width you would multiply 1080 by 1.821 and see that you need a width of 1966.68 to match the aspect of PAL Widescreen. Now you have what you need to know to “crop by numbers”

Before going on to talk more of cropping, I have another main concern and it is about the Preview window and the “Video preview in external monitor” feature. I would be happy with just the Preview window but, if I understand correctly, there is no color management there so you see very different color than the ones you’ll get in the ouput. So I need to use the color managed external monitor preview, right?

Yes, in fact you should calibrate your secondary display with a hardware calibrator like a Spyder3 (which I use) and create a profile that can be used in Vegas. This is the only way that you can trust the colors as our eyes are not sensitive enough to do it manually.

Scale output to fit display = OFF – 1600×1200 is bigger than 1440×1080 so no scaling required, right?

Wrong, but I’ll explain why in the answer to the next question.

With project settings like HDV 1440×1080 PAR 1.3333, the preview on the external monitor is always using all the 1600 pixels for the width: do I have to think that 1440×1080 is always rendered as 1920×1080ù’ (as the “Display” dims shows if I set the “Scale video to fit preview window” at OFF) If yes: why? And then: how this will influence the cropping?

Your PC display has square pixels so you must convert your 1440 to square pixels (remember 1440 * 1.3333) which is 1920. Your video is 1920×1080 in square pixels so your 1600 display cannot display the full horizontal resolution. I would keep scaling ON so that you can see the entire frame.

If you think this subject, and the way we are treating it on this thread, could be useful for other people too, I’ll be glad to help taking it on a more general path along the way.

I think it’s fine where it is. This is all the stuff you need to know about cropping.

Isn,t there a “Quote” button in this forum? I see only “Replay”, “Like” etc…

No, you must cut and paste the text that you want to quote and then indent it yourself like we are both doing.

~jr

http://www.johnrofrano.com
http://www.vasst.com

[Fabio Mereghetti]

Thanks again.

I tried and rendered a 1440×1080 1.3333 clip to a Mainconcept DVD Widescreen mpeg 2 (720[1049]x576) format and I got this results:

1 – If I crop to match the ouptput aspect ratio, the output I get is 1024×576, measured with a screen capture utility with the file open in VLC or MPC HC.

2 – If I don’t crop to match the output, I get an image of the same size if I consider the two black bands on the sides (pillarboxed?).

So, in fact, no 1049 but 1024 instead: how do you explain that?

If I crop to, let’s say, 1216×890 and render + project settings are at DVD wide (720 [1049]x567), will I loose more quality than rendering the original 1440×1080 to the same DVD wide template?

I’m asking this because I’m deshaking some hand-taken clips with Mercalli Expert v1 but I want to have the complete control over the cropping. Since I’m starting from a 1440×1080 clip to get a 720×576 output I think there is room enough to avoid upscaling and borders rebuilding. Am I correct?

Thanks.

[John Rofrano]

I tried and rendered a 1440×1080 1.3333 clip to a Mainconcept DVD Widescreen mpeg 2 (720[1049]x576) format and I got this results:

1 – If I crop to match the ouptput aspect ratio, the output I get is 1024×576, measured with a screen capture utility with the file open in VLC or MPC HC.

2 – If I don’t crop to match the output, I get an image of the same size if I consider the two black bands on the sides (pillarboxed?).

So, in fact, no 1049 but 1024 instead: how do you explain that?

If you rendered using Vegas’ DVD PAL Widescreen setting then your render is 720×576 PAR 1.4568. If other programs are interpreting that incorrectly then that’s their mistake. the video is “physically” 720×576 and if you take a snapshot from the Vegas timeline it will correctly give you a 1049×576 still image.

I’m asking this because I’m deshaking some hand-taken clips with Mercalli Expert v1 but I want to have the complete control over the cropping. Since I’m starting from a 1440×1080 clip to get a 720×576 output I think there is room enough to avoid upscaling and borders rebuilding. Am I correct?

If you want to stabalize your footage, you should render 1920×1080 PAR 1.0 out of Vegas and then bring it back into Vegas to edit. This will keep your cropping options open.

~jr

http://www.johnrofrano.com
http://www.vasst.com

[Fabio Mereghetti]

If you rendered using Vegas’ DVD PAL Widescreen setting then your render is 720×576 PAR 1.4568. If other programs are interpreting that incorrectly then that’s their mistake. the video is “physically” 720×576 and if you take a snapshot from the Vegas timeline it will correctly give you a 1049×576 still image.

Gspot says the file PAR is 1.422.

I tried with Mainconcept and CCE but the result is the same.

I also see a lot of this kind of issues (1.422 vs 1.4568) but
I haven’t found the ultimate answer.

Unfortunately, I’m afraid, this would lead to a quality loss even
at the last stage when the DVD player or the TV will stretch the
1024 to fill the 1049 width.

This is really strange…

Now, let me take advantage of your vast experience as a Mercalli user;-)

I have many clips I shot with a Canon HV40 in my hand, mostly with my arm stretched over my head. I was shooting an essay gymnastics and there are a lot of trembling, quick nasty movements and trials to follow the performer resulting in uneven panpotting. To me, it sound as the best source Mercally would like to deal with…

All these clips were shot and captured in HDV 1440×1080 50i (Italy is a PAL land).

I’m using Expert v1019. I tried some of the presets but it’s not easy to know if there is one that works better than the others.
I read the Mercally manual but I think people experience it’s always the most valuable thing to seek: have you any advice to give to me?

I see you gave me the first one already – to convert to 1920×1080 PAR 1.0: why are you giving me this hint? Just to be able to crop to 1/1920 instead of 1/1440 or for some other reason too?

I’m doing some “Extras” to put into the DVD I will distribute to the other parents involved. The nicest is a slo-mo to 1/4 of just the somersault after a normal speed run. To get the smoothest slo-mo effect I’m following the advice to transform the clip from 50i to 50p and do the slowing after that: is it better to apply Mercalli before or after the 50i to 50p conversion?

I’m using Cineform HD during all my editing process: will Mercally introduce any softness when applied even if I don’t use its scaling function?

Thank you.

Maybe I will try to put a clip somewhere to let you see the defects I’m working on.

[John Rofrano]

Unfortunately, I’m afraid, this would lead to a quality loss even at the last stage when the DVD player or the TV will stretch the 1024 to fill the 1049 width.

I think you’re missing the point so let me make it again. PAL Widescreen is 720×576. The image is only 720 pixels wide. There is no stretching from 1024 to 1029 because there are only 720 pixels to start with. So regardless what what PAR the DVD player thinks the file is… the file is 720 pixels by 576 pixels and it’s going to get stretched to make it widescreen. I doubt highly that you can tell the difference with the naked eye whether 720 pixels get stretched to 1024 or 1049, they are going to be stretched either way.

I see you gave me the first one already – to convert to 1920×1080 PAR 1.0: why are you giving me this hint? Just to be able to crop to 1/1920 instead of 1/1440 or for some other reason too?

I recommended that in case you were using any programs outside of Vegas to process the files. This eliminates the PAR problem. If you are using the Mercalli plug-in then you can just render back to your source format or Cineform (I see you have Cineform)

To get the smoothest slo-mo effect I’m following the advice to transform the clip from 50i to 50p and do the slowing after that: is it better to apply Mercalli before or after the 50i to 50p conversion?

I would apply Mercalli before the slo-mo. Mercalli is expecting the video to be real-time when it estimates the motion. It will see a fast camera jerk and smooth it out. If you slow it down, it might see a slow jerk, think that it’s a deliberate camera move and keep it in.

I’m using Cineform HD during all my editing process: will Mercally introduce any softness when applied even if I don’t use its scaling function?

Mercalli doesn’t introduce softness… The process of stabilization itself produces softness. Fast moving video has motion blur. When you watch it in real-time, our eyes understand that the blur is caused by the motion. When you stabilize it, the blur becomes painfully obvious because a still image should not have motion blur. There is no way to fix this other than using a tripod in the first place. 😉

~jr

http://www.johnrofrano.com
http://www.vasst.com

[Fabio Mereghetti]

I would apply Mercalli before the slo-mo. Mercalli is expecting the video to be real-time when it estimates the motion. It will see a fast camera jerk and smooth it out. If you slow it down, it might see a slow jerk, think that it’s a deliberate camera move and keep it in.

So, it is better to apply Mercalli to the original HDV 50i (50 “half-frames”) then to the interpolated 50p (50 “full frames”)?
Of course, in this case the project settings frame rate will be 50 fps.
I made a copy of the template I’m using in my project and created a new template with the same exact name but with “prodad mercalli” at the beginning: is this the only way to tell mercalli which template to use when rendering the effected clip?

What about interlacing? Shall I have to leave the clip interlaced or it is better to do some de-interlacing before applying Mercalli?

Thanks.