Usage of 720x576 vs. 704x576 with widescreen material - which is professionally used?

[rse]

Hi!

I´m on revising my website and now I´m not sure about the following (assuming you all know the difference between 704x576 and 720x576, which is slightly wider):

On Wikipedia I found, that the 4:3 Picture on 35mm Film is actually 1.375:1 and not 1.333:1, so there is no problem in using 720x576, which is only 1.3675:1.
I guess a digital video camera capturing anamorphic 16:9 video does it in 720x576, so that it actually captures a picture of 1.82333:1 (720*1.094PAR for PAL/(4:3)*(16:9)/576). Can anyone please confirm this guess?

Assume there is a source video in aspect ratio 2.39:1 (cinemascope since the 70s, according to wikipedia) and I want to make a DVD from it. What do I do?
1) letterbox to 16:9 and encode using 704x576 Pixels -> gives me 321 active lines of Video
2) letterbox to 16:9 and encode using 720x576 Pixels -> gives me 329 active lines of video, but the effective picture on a 4:3 display isn´t as wide as 2.39:1 anymore...
What is the common procedure in professional DVD authoring? I assume option 2) since most DVDs are in 720x576.

[sillKotscha]

http://forum.doom9.org/showthread.php?t=42708

[rse]

Sorry, I forgot to include anamorphic resize to my calculation above. Correct number of active lines should be 1) 428 active lines and 2) 439 active lines.

Anyways, I don´t get how the thread you posted answers my question... It only clarifies how to transfer from DVD to 1:1 PAR, but that would work properly in both cases:

1) We have 704x576 anamorphic with 428 lines of active video (rest black from letteroxing the 2.39:1 in 16:9). Resizing to 1024x576 according to ITU and anamorphic saving on DVD to get 1:1 PAR, cropping the black bars and we have 1024x428, which is perfectly 2.39:1.
2) We have 720x576 anamorphic with 439 lines of active video (rest black from letteroxing the 2.39:1 in 16:9). Resizing to 1050x576 according to ITU and anamorphic saving on DVD to get 1:1 PAR, cropping the black bars and we have 1050x439, which is perfectly 2.39:1 again.

So which one is right? 1) or 2), or even both, so that I can choose by myself which I would prefer?

[DewAsmara]

To be honest,
Most people using letterbox cropping into original 4:3 video to made widescreen effect. But Anamorphic also not a bad idea, as long as you can accept the result. My original DVD Underworld2 have 4:3 aspect ratio that by the copyright distributor they anamorphically into 16:9 aspect ratio to fit onto LCD Display. But then I resize it into widescreen 2.35:1 because part one have original aspect ratio 2.35:1 that they also anamorphically into 16:9.

[zambelli]

The quick answer is that 704x576 is the active area of the ITU.601 image, while 720x576 is the maximum size of the DVD image. All aspect ratio calculations are and should be based on the 704x576 image. Even though 704x576 is supported by the DVD standard, most encoders use 720x576 anyway.

DVDs made from TV content will typically only contain a 704x576 active image and black out the 8 pixels on each side. Film content, on the other hand, will typically use the full 720x576 frame (while calculating an aspect ratio based on 704x576). This can be easily done by resizing the video to 720x588 and then cropping the pixels from top and bottom to 720x576.

[PhillipWyllie]

Makes no difference what size if you are authoring a DVD, your TV(widescreen TV) is going to resize it to an apparent 1024*576 anyway(by stretching), although menus should be 720*576. I notice no difference between the two except that 720*576 is a little sharper(looking at the video on a PC not a TV). I've found on some DVD players if you use a vertical size of 288 problems occur.