Mix of HDV and DV

L_Town wrote on 9/11/2009, 9:55 AM

I am currently working on a project that is mostly 720 X 486 4:3 SD. This footage has a pixel aspect ratio of .9091. My project properties match my footage (720 X 486).

I now need to add some NTSC HDV footage (1440 X 1080) to this project. I need to know how to resize my HDV footage to match the 720 X 486 4:3 SD footage. I have tried changing the pan/crop of my HDV footage to a width of 1104.6 and a height of 1080.0 but this does not help when I render out to my 720 X 480 MPEG-2 DVD file.

When I play my DVD, the HDV footage extends outside of the 720 X 486 footage. For example, I have one scene that has 720 X 486 footage on top of my HDV footage. This creates a "border" of the underlying clip.

I think it's a pixel aspect ratio issue. This sounds like a calculation error that I need to solve. Any suggestions?

-Brian

Comments

johnmeyer wrote on 9/11/2009, 10:13 AM

My workflow for HDV to SD projects

L_Town wrote on 9/11/2009, 11:22 AM

Hi John. Thanks for responding.

I actually followed your guidelines from the start before I posted this thread. I have used your guidelines in the past and have had great success. However, in the past it was all HDV footage on the timeline.

Can you assist me with NTSC 720 X 486 SD 4:3 footage mixed with HDV on the same timeline?

L_Town wrote on 9/11/2009, 11:35 AM

I guess I am actually mixing D1 with HDV...

johnmeyer wrote on 9/11/2009, 11:48 AM

If you click on the link I provided above, and then in that thread click on another referral, you end up in the thread where I calculate the "magic number" needed to do an exact crop for SD DV to HDV:

HDV to SD Crop Procedures - magic numbers

You can click on that link and read what I wrote then.

Since you are apparently using a slight variant of NTSC DV, I think all you have to do is substitute your numbers and turn the crank on the calculations I posted in the link I provide two paragraphs above.

I just cut/pasted from that link, and then substitued your numbers and this is what I get:Format aspect ratios (for NTSC)
HDV 1080i is 1440 x 1080 which is a ratio of 1.3333
D1 (NTSC) is (apparently) 720 x 486 which is a ratio of 1.48148148

Pixel aspect ratios
HDV is 1.3333
D1 is 0.9091

The number 1.3333 shows up twice, but that same number refers to different things (they are related, but they are independent, different things).

The calculation is:,

1440 x (1.48148 / 1.333) x (0.9091 / 1.3333) = 1090.92

Thus, you unlock the "lock aspect ratio" button in the pan/crop dialog, and then enter 1090.92 for the position width.

L_Town wrote on 9/14/2009, 5:45 AM

Ohhhh ok. I do remember seeing and reading your post about "magic numbers". Thanks for plugging my numbers in! I will try that out today.

ScorpioProd wrote on 9/14/2009, 11:34 AM

But... You said you're trying to make a DVD, a DVD is 720X480.

So you should be working in a 720X480 project and cropping your 720X486 footage to that.

And the easy way to do that is with the "Match output aspect" in the pan/crop.