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Graham Morton May 20th, 2005 06:15 PM

Newbie to AE
 
I am a newbie to AE and just wanted to know how everyone is setting up there comps for HDV. I have read some of the other posts but still can't seem to get it set up right. Any comments?

Randy Donato May 20th, 2005 08:35 PM

Steven White gets all the credit for this gem....you need to set AE up so it will recognize the 1.33 to 1 pixel aspect ratio of HDV... to do that do this:

After Effects 6.0/Support Files/intepretation rules.txt

file, taking the bottom line:
# 0, 0, 0, "0000", * = 10/11/"Custom Aspect", *, *, *

and changing it to:
0, 0, 0, "0000", * = 4/3/"Custom Aspect", *, *, *

After you have done that you can open a comp in a 1920x 1080 HD preset and and it displays just perfect. Remember that is the resolution it will be displayed at using square pixels as the PAR. I have seen some HDV sized clips not get recognized as 1.33 and if you run into that just change the PAR in "interpret footage"....but that is rare and comes from work with stills grabs from HDV. You need to do the same in Photoshop....meaning create a custom PAR of 1.33 and view a still from HDV using that par....or you can resize it to 1920 and it displays just like it should but the nle may now see it different once it is resized.....Edius doesn't

Steven White May 25th, 2005 02:31 PM

Quote:

you can open a comp in a 1920x 1080 HD preset
Even better is to make a 1440x1080 comp with a custom PA of 1.33. This forgoes any scaling of the 1440x1080 source, and renders all objects with a 1.33 PA. Furthermore, you can save this as a Custom Pre-Set if you like (by simply clicking the "save" icon in the "New Composition" window).

When you've got this all finished, if you have an appropriate version of the media encoder (included in Premiere Pro 1.5 - I haven't tried in AE yet), you can even export an anamorphic 1440x1080 WMV file for your viewing pleasure (and if you crop to 2.35:1 you can export a 1440x818 file too!).

This is what it looks like:
http://s94963366.onlinehome.us/HDRFX1/compsett.jpg

-Steve

Sean M Lee May 25th, 2005 05:06 PM

Steve,
that assumes that you will be rendering out to HDV. I haven't done any graphic work yet for HD or HDV, but I'm dig'ing some stuff now to try. I think I'd set up my comp full HD size so I had as much resolution as possible for the final product.

Am I wrong?

Randy Donato May 25th, 2005 06:40 PM

Hi Steven, I have set it up as you describe(1440x1080) however the overlay preview takes on a 4:3 look which is not how the footage will be displayed at 1920x1080. For some reason, unlike Photoshop and selecting 1.33, it does not take on a true 16:9 display. I use the Canopus Nx card for video out and it knows to scale it to 1920x1080 so it looks fine on video out but the preview in AE isn't 16:9. In the end it doesn't matter since any effects will scale equally when it is viewed 1920x1080...but I don't see any downside to using the 1920 setting....it doesn't change the source but sees the 1.33:1 and coverts for display to 1:1(which is how it will utimately be displayed)so outputting like I do to Canopus HDV(1440x1080 par 1.33) codec(HQ) isn't affected.

Steven White May 25th, 2005 08:07 PM

By default After Effects displays square pixels. (i.e., 4:3 in the case of HDV)... However, there is a button in the workspace window that allows you to "Toggle Pixel Aspect Ratio Correction" (see here: http://s94963366.onlinehome.us/HDRFX1/PAtoggle.jpg ), which will then display the image in the 16:9 ratio you expect.

I suppose if you want to get your text graphics "extra sharp", it's worth making a true 1920x1080 composition... but ONLY if you're rendering to 1920x1080 as a final output. (Also, if you were doing pure CG - I don't see why you wouldn't render 1920x1080 to master).

However, if you are rendering to 1440x1080 codec like you suggest, After Effects will FIRST upsample by 1.33 to render the video at 1920x1080, then downsample again by 1.33 to the 1440x1080 render. I doubt that this is a lossless process, as pixel information gets distributed in the 1920 render that cannot be recovered exactly... I could be wrong, but I doubt the software is that smart. Rendering all the text and graphics with a 1.33 PA will create optimal text for a 1440x1080 file as well, so there is no benefit to rendering it at 1920x1080 and then downsampling to a 1440x1080 render.

Certainly if you are applying effects with adjustment layers, there's absolutely no benefit to a 1920x1080 composition, as it will take 1.33x as long to render, but acheive no additional resolution. Any effects applied to the original HDV layer shouldn't be affected.

In short - I don't personally see why you would be inclined to render at 1920x1080 without 1920x1080 source. Likewise for using 854x480 compositions for DV widescreen.

-Steve

Randy Donato May 25th, 2005 08:46 PM

Thank you once again for the toggle tip....obviously that is the correct way to go. On the "upsample" I am confused since there is really isn't any true upsample since you are taking pixels that are in a 1.33:1 aspect and changing them to square....1.33 x 1440 =1920 square pixels....I just wished AE supported HDV better. I am sure they will accomodate soon...for $ Thanks again for another great tip.

Steven White May 25th, 2005 09:09 PM

Quote:

I am confused since there is really isn't any true upsample since you are taking pixels that are in a 1.33:1 aspect and changing them to square
Well - it really is a digital upsample - you take pixels that are 1.33 times as wide as square ones, and stick them in square holes. If you lay out a square grid, you can immediately see that 1.33 doesn't fit into those holes evenly, meaning some 1.33 pixels will be spread across two pixels, etc.

The fact of the matter is, pixel aspect ratios SUCK for digital displays. On a CRT, while the number of lines is discrete, the horizontal resolution is analog. When you pass a "1.33 PA" signal into CRT, it simply multiplies by 1.33 and makes it fit the display. Since the 1.33 can be an analog number, it makes no difference. On a square-pixel digital display though, it has to digitally convert the signal to its native resolution... which necessarily corrupts the original digital information.

People seem to think the days of CRTs are nearing a close... but it's fairly obvious from the 1080i HD standards and implementation thus far... interlace and pixel aspect ratios only really work well on CRTs. *sigh*

-Steve

Randy Donato May 26th, 2005 06:54 AM

I have a Sony HR crt and at first used a 1080i LCD.....which now makes a nice editing monitor:) Steven are you using Aspect or any other Cineform product? I use Edius and Canopus HQ but have some work I want to do In Ppro so I have Aspect. What is strange is using the tweaks to create 1.33 PAR and using the PAR toggle everything works display wise fine in AE using Canopus HQ...however the aspect captured clips look like 4:3 and do not fill the display but do go out full res through the Nx card to the crt...strange Here is a pic http://www.rdonato.com/aspect.jpg If I do interpret footage and select 1.33 it displays fine...bottom line Ae has no problem seeing the HQ as 1.33 PAR but with Aspect it sees it as square and it has to be changed.

Steven White May 26th, 2005 07:30 AM

Hey Randy:

I'm running Premiere Pro 1.5.1 with a demo version of AspectHD 3.1 at the moment. I will be buying AspectHD if I can earn enough money shooting footage with my FX1 to cover the expense.

It looks to me like you need to configure the interpretation rules for the Cineform clip. Sometimes the After Effects doesn't notice the 1.33 PA in the file header. To fix it, right click on the clip in the project window, and select "Interpretation Rules, Main" (alternatively, click on the clip in the project window and type "CTRL+F"):

http://s94963366.onlinehome.us/HDRFX1/intepret1.jpg

In the window that comes up, change the pixel aspect ratio to 1.33:

http://s94963366.onlinehome.us/HDRFX1/interpret2.jpg

If you've already done what I suggest above, then I'm confused... What does the file look like when rendered? If it looks appropriately stretched then I have no clue what's up, but it's probably a "bug" or a "feature".

-Steve

Randy Donato May 26th, 2005 07:45 AM

I caught the interpret footage option and edited my post....you are too fast for me :) Funny that it sees the 1.33 PAR of Canopus HQ fine and I don't have to "interpret".

Steven White May 26th, 2005 07:53 AM

Well, if you end up having a lot of files to interpret, you can click "Remember Intepretation", select a whole bunch of files, and "Apply Interpretation" to the lot of 'em in one fell swoop - so it's not a big productivity killer. I've had similar problems with DV videos and uncompressed renders as well... you're bound to encounter it fairly often, so it's worth being aware of.

Too fast eh? Must. Stop. Spending. Time. Online.

-Steve


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