Deadline! 720P30 to SD-NTSC Aspect problems.

Chadfish

Chadfish

Veteran
Hi

Spot in Question: http://www.youtube.com/watch?v=GlnmsvZEeDc

I'm on a last minute deadline for an ad I shot on the EX1 at 720P30. I have edited it in HD and output a final file. I have taken the file and dripped it into an SD timeline and output one file. It looks pretty soft, and the aspect ratio is off a little.

My other method looks great, but the aspect is still just a tad off by the time it gets on TV, or viewed in my iDVD.

Here's the recipe for that:
-Then use Quicktime Conversion...
-Settings
•Type= H.264
•Frame Rate = current
•Key Frame = all
•Data Rate = automatic
•Quality = best
-Size
•Dimensions = NTSC 720x480 4:3
check yes to preserve aspect ratio (letterbox)
check yes to deinterlace source video

One friend said to distort the image to -33 first, but that looks very wide stretched. Without any distortion (in the motion tab) it comes out close, but still slightly wide stretched.

Does anyone have a clean recipe for taking a 16x9 HD file, and exporting for SD NTSC TV while retaining proper aspect? I realize that when working at 720x480, things look a little stretched wide - then when it plays on the set it resolves it to 720x534 and looks correct.

Thanks for a quick response.

Chadfish
 
Have you tried using Compressor? I can always find a preset that does what I need. Then just go in and change the codec to H.264.

I hate dealing with pixel aspect ratio conversions!
 
You have three options:

* Deliver as widescreen standard def. This would work in Europe, but I am not sure whether it is accepted in the States for broadcast, though it used on DVD all the time. If the station airs it as it is, it will be letterboxed on a regular TV, but on an HDTV it may look proper widescreen, depends. You will need to set PAR 1.2121 or something like that, depending whether you output 704 or 720 pixels horizontally.

* Letterbox into 4:3 and deliver as 4:3. If the station airs it as it is, it will be letterboxed on a regular TV and fully boxed on a HDTV. The frame size in pixels is the same as above, but PAR is something like 0.909, search for exact number depending on number of pixels horizontally.

* Crop the sides and deliver as 4:3. The frame size in pixels and PAR is the same as above.

"I realize that when working at 720x480, things look a little stretched wide" -- nothing looks stretched if you set proper PAR.
 
Cranky said:
You have three options:


"I realize that when working at 720x480, things look a little stretched wide" -- nothing looks stretched if you set proper PAR.
Click to expand...

I am delivering as a letterboxed 4:3 image in the US.

How does one set the proper "PAR" in FCP?

I have not had any problems when working SD all the way, though when working the image is slightly stretched, but when it plays on a TV it looks fine. Like if you make a photoshop doc for TV you make it 720x534 while you edit the image, then before you drop it into an SD project you change it to 720x480. It looks a little stretched, but when it gets to TV all is correct. I have never heard the term PAR, but hey I have trained myself up here in the sticks of Northern Humboldt California. The TV stations can't even tell me what they want with certain things like audio levels.

Thanks for the info.

Chadfish

PS: What is a good Compressor preset DrKing?
 
PAR 1.2121 or something like that
Click to expand...

Haha see, people who know what they're talking about aren't even sure.

Shooting with square pixels is great. Too bad we still have to convert to other formats.
 
What is a good Compressor preset DrKing?
Click to expand...

Man... I'm really not sure. Pixel aspect always caused me headaches. You could try "DV NTSC 4:3" and see what happens.

I have a feeling it might just squeeze the widescreen though.

But you could do this. On you native XDCAM timeline export a self-contained QuickTime movie (self-contained may not be necessary). Then put it on a new timeline. Then go to sequence settings and change "Aspect Ratio" to "Custom" and change the height to 960px, giving you an aspect ratio of 4:3.

Now you have a 4:3 sequence that Compressor will downrez and apply the proper PAR.
 
DrKing2010 said:
Haha see, people who know what they're talking about aren't even sure.
Click to expand...
I said, depending on frame size. You can easily calculate it yourself, this is a third-grade proportion:

For 704x480 widescreen: PAR = (480 * 16) / (704 * 9) = 1.2121
For 720x480 widescreen: PAR = (480 * 16) / (720 * 9) = 1.185
For 704x480 4:3: PAR = (480 * 4) / (704 * 3) = 0.909
For 720x480 4:3: PAR = (480 * 4) / (720 * 3) = 0.89

Chadfish, PAR means pixel aspect ratio.

I don't use FCP, I use Vegas.

720x534 makes FAR 1.35 (frame aspect ratio) with PAR 1 (by default). You want it to have PAR 0.89 (see above) with FAR 1.33 (I really don't know why have you chosen FAR 1.35 to begin with). Anyway: 534 * 0.89 * 1.35/1.33 ~ 482. Pretty close to what you are having :-) Why would not you use 720x539 instead?
 
I wish I knew a third-grader who would do all my PAR calculations. I'd trade that for my fruit snacks any day!
 
DrKing2010 said:
I wish I knew a third-grader who would do all my PAR calculations. I'd trade that for my fruit snacks any day!
Click to expand...

You would seriously give up your fruit snacks???!!! I love those things. If I was really hungry I might be willing to trade my EX-3 for one. Only on a good day though. :grin:
 
Pardon my ignorance Cranky. I have no idea what you are trying to show me. It doesn't help that I am dyslexic, and have trouble with even 3rd grade math.

I don't know where 704x480 comes in to play. I don't know what "*" means. I have a slider that allows me to adjust aspect ratio to any numeric value.

I have a self contained file that is 1280x720 ('XDCAMEX 720P30 VBR') That I either put on an SD 720x480 sequence, but it looks soft and slightly off aspect. Or I put it in a sequence that matches it's settings and export anamorphic, though still slightly off looking.

If I understand you correctly, you tell me to set the PAR to 1.185 first, then export anamorphic 4:3?
 
* means multiply.

Take your self-contained file and try what I said earlier. I bet it works. Let Compressor do the math for you.
 
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