Down conversion from HD (720P) to 720X480 letterbox

[Shane Ross]

Just use Compressor. That’s what I do. It’ll Compress the 720p down to 720×486 with black bars just fine.

Shane

Littlefrog Post
http://www.lfhd.net

[David Roth weiss]

[Shane Ross] “Just use Compressor. That’s what I do. It’ll Compress the 720p down to 720×486 with black bars just fine.”

Shane,

As I’m sure you know, the proper dimensions for DVDs are 720×480, not 486. Probably caffiene related.

David

“No job is worth doing more than once…”

David Roth Weiss
Director/Editor/Post-production Supervisor
David Weiss Productions, Inc.
Los Angeles

[Shane Ross]

[David Roth Weiss] “As I’m sure you know, the proper dimensions for DVDs are 720×480, not 486. Probably caffiene related.”

Really? How can this be? SD is 720×486…always has been. DV introduced the 720×480 dimensions.

SO you are telling me that the DVD of CASINO ROYALE I have is 720×480? Why? and why would DVD SP format to 720×480 when standard def dimensions are 486?

Shane

Littlefrog Post
http://www.lfhd.net

[Pierre Tremblay]

Well, that’s what I did and didn’t get the letterbox “boxes” on the file, just an anamorphic
file. I looked at all the Compressor settings and didn’t find where to select for a letterbox
compression.

Pierre

[Shane Ross]

COmpressor doesn’t have the 16:9 setting. DVD SP has that. THAT is where you tell it to letterbox the footage.

Shane

Littlefrog Post
http://www.lfhd.net

[David Roth weiss]

Shan[Shane Ross] “SO you are telling me that the DVD of CASINO ROYALE I have is 720×480? Why? and why would DVD SP format to 720×480 when standard def dimensions are 486?”

The DVD spec is 720×480 for NTSC. I didn’t write it personally.

FYI, here are all the file sizes that conform to the DVD spec.

Coded frame sizes:
525/60: 720×480, 704×480, 352×480, 352×240
625/50: 720×576, 704×576, 352×576, 352×288

David

“No job is worth doing more than once…”

David Roth Weiss
Director/Editor/Post-production Supervisor
David Weiss Productions, Inc.
Los Angeles

[Pierre Tremblay]

Thanks Shane,

DVD SP worked, it was the last missing link.

Pierre

[Michael Hendrix]

The 720X480 spec was introduced for DV and stuck with DVD production. With what little I know, 486 is not divisible by 4, 480 is which is the colorspace DV works in. Digital color sampling works in 4 pixel increments, i.e. 4:2:2, etc.

Someone else is welcome to chime in because that is about as much as I understand.

[David Roth weiss]

[Pierre Tremblay] “Well, that’s what I did and didn’t get the letterbox “boxes” on the file, just an anamorphic
file. I looked at all the Compressor settings and didn’t find where to select for a letterbox
compression.”

Pierre,

In the future, just so you know, if you encode widescreen in Compressor and author in DVDSP and it will create a DVD that automatically displays 4×3 letterboxed on SD TVs and 16×9 on widescreen TVs.

David

“No job is worth doing more than once…”

David Roth Weiss
Director/Editor/Post-production Supervisor
David Weiss Productions, Inc.
Los Angeles

[Tom Brooks]

It has more to do with the macroblock structure of the codec. MPEG-2 frame sizes should be evenly divisible by 16. That’s for encoding and decoding efficiency. Then you have the allowable frame sizes in the DVD spec on top of that. Ben Waggoner’s book on comression (Compression for Great Digital Video) has some pretty good info on this in layman’s terms.