Which is best: progressive or interlaced source footage?

DataMeister wrote on 3/25/2003, 10:13 AM
If I'm letting DVD architect do the compression is it better to give it progressive frames or interlaced frames as the source footage? What will the final output be on the DVD?

I've always wondered if those progressive DVD players are converting interlaced to progressive or if all players are converting progressive frames to interlaced.

JBJones

Comments

RBartlett wrote on 3/25/2003, 1:50 PM
If your source is interlaced, to give the MPEG encoder the frames dressed as progressive will result in a upwards step in bitrate because both the intraframe and interframe compression will have more information in it than a truly progressive frame would have.

Many DVDs are progressive where taken from film, and optionally 24fps layed down on the DVD (saving space and using the pulldown or time stretching (NTSC60/PAL50 respectively).

24p, 25p, and 29.97p are outside the abilities of DVDA. If progressive comes, hopefully both frame sizes and all three rates will also become available. Simply the headers of the MPEG-2 won't show progressive after authoring.

If you truly have a progressive source, you might manage to get the results you want on many targets, but by fluke, not design.

Most non-hollywood DVDs are interleaved, on entry to Vegas and on exit from DVDA. Progressive players can normally drive their collaberative TV sets in interleaved, or "de-interlaced" for this type of media.

Hopefully my statements regarding this restriction will very soon become out of date.
DataMeister wrote on 3/25/2003, 4:40 PM
So what you were trying to say is that DVD-A outputs interlaced video no matter what you feed it? And it probably wouldn't affect the quality of compression to send one or the other?

I'm taking computer generated animations (which are progressive) along with some still images into Vegas and then saving the composition for use as menu backgrounds. So it could be either progressive or interlaced. Just depends what I tell it during save.

That's why I was wondering how DVD-A stored the info.

JBJones