Field order in NTSC DVD

[hatetea58]

I am using Adobe Premiere and Encore.

In Encore, NTSC DVD field order is set to lower and can't be changed.

The source is from Canon AVCHD, which Media Info shows as TPP (upper).

The encoder has a choice for lower or upper, with lower as the default.

How would this affect the video quality? Does the encoder simply shift one frame to convert upper to lower?

thanks!

[SomeJoe]

In Adobe Encore, the field order selection is to select what field order the source file is. The encoded file will be correct if this is set right.

Generally, most NTSC DV AVI files from standard definition camcorders are lower field first. AVCHD files from high definition camcorders are generally upper field first.

When the file is encoded, the encoder can do it one of two ways:

1. The input field order is used to determine the output field order. So for NTSC DV AVI files which are lower field first, the encoder will produce an output MPEG-2 file that is also lower field first.

2. The encoder can shift the fields such that no matter what the input field order is, the output field order is a certain type. Upper field first is recommended and is the de-facto standard for MPEG-2 on DVD, so if the input file is lower field first, the encoder shifts all fields up (or down) one scan line to reverse the field order.

I do not know which method Adobe Encore uses. But you don't need to worry about it, since the final output will be correct if you set the input field order correctly.

If a file is encoded in the wrong field order, there will be a noticeable jitter during movement when the file is played back.

Note that field order only applies to interlaced footage. If the footage is progressive, field order doesn't really matter.