what is this 1.33:1 pixel business ?

[Kevin Camp]

unfortuantely compressed hd is often non-square, both hdv and dvcprohd have a resolution of either 960×720 or 1440×1080. which if you do the math is a 4:3 ratio. so to get it to 16:9 they use a 1.33 pixel aspect ratio.

you can, however, just drop that footage into a hd sqaure pixel preset comp (either 1080 or 720 preset depending on footage) and ae will handle the non-square to square conversion, and it is a common way to work with these codecs.

Kevin Camp
Designer – KCPQ, KMYQ & KRCW

[Darby Edelen]

1280×720 is the correct size for a square pixel 720p comp.

Some codecs used for capturing use a pixel aspect ratio in order to compress the size on disk/tape of the HD frame, most notably HDV and HDCAM.

Darby Edelen
DVD Menu Artist
Left Coast Digital
Aptos, CA

[Mark Wilkinson]

ok, thats helpful. when i drop the footage into the HDTV preset its sitting wider than the comp area – should i just change it to square in “interpret footage” or scale it in the comp ? thanks !

[Darby Edelen]

[mark wilkinson] “when i drop the footage into the HDTV preset its sitting wider than the comp area – should i just change it to square in “interpret footage” or scale it in the comp ? thanks !”

You should use the Interpret Footage dialog. If the true resolution of the footage is 1280×720 then a Square Pixel aspect ratio should be correct.

Darby Edelen
DVD Menu Artist
Left Coast Digital
Aptos, CA

[Steve Roberts]

Sometimed DVCPROHD 720p comes in at 960×720 with a non-square PAR (pixel aspect ratio). That is correct, as is 1280×720 with a square PAR.

AE7 and CS3 have treated them differently in my experience, also depending on where the footage was coming from. As long as you have the correct size and PAR *combination*, you should be fine. In my opinion. 🙂

[Tim Kolb]

I think there may be some confusion here…

Just so we’re clear on tape/file formats:

Frame size, PAR/File frame size,PAR

DVC Pro HD

1280x720p, square/960x720p,non-square
1920x1080i, square/25fps 1440×1080 non-square
1920x1080i, square/29.97fps 1280×1080 non-square

*HDCAM

1920x1080i/p square/1440×1080 non-square

HDV1

1280x720p square/1280x720p square

HDV2

1440x1080i non-square/1440×1080 non-square

*Since there is no way to transfer HDCAM as native data into anything but an XPRI (do they still make those?), HDCAM is in typical cases, never handled at its 1440×1080 stored size.

DVC ProHD, because of its FireWire and P2 workflows is often handled at its subsampled size of 960×720, unless it’s fed into an editing system via HDSDI, in which case it’s fed as full 1280×720 as SDI only does square pixel.

HDV1 (JVC’s 720p variety) is square pixel, and full raster 1280×720. When it is output via HDSDI, no PAR conversion is necessary as it’s already square pixel.

HDV2 (Sony/Canon) is file transferred into most NLEs via FireWire for native editing at 1440×1080 non-square, which is it’s actual size, not a subsample. When this material is fed via HDSDI, as you might from some of the newer camcorders, it must be up-converted to square pixel 1920×1080.

TimK,
Director,
Kolb Productions,

Creative Cow Host,
Author/Trainer
http://www.focalpress.com
http://www.classondemand.net

[Steve Roberts]

There’s a post worth saving. 🙂