29.98 v. 23.97fps DVDs

[DavidBeier]

If you shot 24p you certainly won't get motion that looks like 60i; it's just not going to happen. However, if you're mixing your pulldown then it wouldn't surprise me if you're getting some motion artifacts. If you're shooting 24pA the pulldown is 2:3:3:2. The NLE will just delete every third split frame to get a true 24p. In regular 24p however, you're only doing 2:3. The third frame is spread across two split frames and has to be extracted and rebuilt. If you're trying to mix that into a 24pA timeline, thenit means that you're just dumping the one of the split frames and then seeing only half of the origional 3rd frame. This could make parts of the motion look speed up as you describe.

In other words:

24pA:

A Frame (two fields), B Frame (two fields), Split frame half B half C, C Frame (two fields, D Frame (two fields)

The third frame is then dropped to be pure A, B, C, D, E, F

24p

A frame (two fields), B frame (two fields), Split frame half B half C, Split frame half C (other half) half D, D frame two fields.

Extracting using the 24pA pulldown however would give you:

A, B, Split frame half C half D, D, split frame half E half F, F

The result is that every other frame is being chopped in half. This will certainly look odd.

 

[Justin Reade]

David, YES YES -- that is most likely the reason why there are motion issues. Thank you very much for the clarity in your response. That makes a lot of sense. I knew there had to be some motion issues when you fuse straight 24p and 24pA footage together in one timeline.

Edgemin, do not worry whatsoever about the anomaly that you are finding in DVD STUDIO PRO. It is a known problem with the software that it wrongly/incorrectly identifies your movie file as being "29.98" when it really is, in fact, "23.97."

A television is not going to brute force you into 60i. If you purchase a DVD, i.e., a commercial one like any major motion picture, you are seeing 24 frames per second because that's is the speed frame rate of actual FILM in which it was originally shot -- you can't ADD frames to that. So, assuming you shot your movie, etc., with the HVX and edited it in a 23.97 timeline in Final Cut Pro, or what have you, you will be yielding a 24p product.

Check your Quick Time movie file. You will note in its "Properties" that it's 23.97. Don't worry about what DVD STUDIO PRO says, as I noted above. The bizarre issue discussed previously in this thread, and I believed answered very competently by David, is that I stupidly dropped straight 24p footage into a timeline along with 24pA footage and noticed motion effects in the final DVD product. In an effort to diagnose why this was happening, I was conjecturing a lot, and felt (I guess rightly) that my 24p and 24pA blend was a potential cause/factor. Makes sense why, based upon the pulldown.

Anyway, author away. Your 23.97 project will burn as a 24p DVD and you're good to go! As a test, why not shoot something on the HVX in true 60i and then author a DVD of that footage? I haven't tried it, but my guess is, you will see the appreciable difference in frame speeds.