broadcast frame size and dvds

masmedia wrote on 5/12/2005, 6:57 PM
hello,

I'm confused. I thought broadcast size was 720X540. My Vegas renders MPEG2's at 720X480. In Photoshop it says the NTSC standard is 720X540.

MPEG2 IS the right "standard" DVD format, right? It will play in a regular DVD player, will it not?

What is TV size in NTSC? Is it 720X540 or 720X480 or 720X486?

Thanks for your help! I know I should know this, but I need a nudge in the right direction!

Comments

John_Cline wrote on 5/12/2005, 8:18 PM
NTSC DV and DVD is 720x480
NTSC CCIR 601 "D1" is 720x486

Actually, CCIR 601 is the old name of a standard published by the Consultative Committee for International Radio (CCIR), SMPTE and the European Broadcasting Union for encoding interlaced analogue video signals in digital form. The new name of the standard is ITU-R BT.601.

Now, about 720x540...

Although a video picture is actually 720x480, its pixels aren't square; they're shorter than they are wide. In other words, if a circle is grabbed from videotape and displayed on a computer screen, it will appear to be an oblong, slightly wider than it is tall. Similarly, if a circle is made on a computer screen at 720x480 and output to video, it will also appear slightly oblong, slightly wider than it is tall.

To compensate for this, if an image is made at 720x538, and then squished to 720x480 just before output, the aspect ratio and size will be correct for output on a standard 4x3 TV screen.

720x540 is the value to use if you are working in "D1" at 720x486.

John