End credit roll interlacing issue (yes, I’ve tried ideas in other threads)

[Franky Torres]

I experienced the same exact thing. Film credit roll flicker for a 2k film out. In my case it had to do with the text moving at a sub-pixel rate, rather than whole numbers for each frame. take a look at this

https://forums.creativecow.net/cgi-bin/new_read_post.cgi?forumid=2&postid=904689

[Ecourtney]

Unfortunately, I’ve tried the Mercury Jones preset and it didn’t work for me. I would appreciate any other ideas.

Also, since I am doing a DI the solution needs to work for both film and NTSC video frame rates as the timing must be the same for both.

Erik

[Steve Roberts]

Try this: render with no fields and use a different encoder (such as Compressor or Squeeze) that gives you control over interlacing.

[Ecourtney]

Hey Steve,

I’ll definitely try that. Do you have any recommended settings for compressor or squeeze?

Thanks!

Erik

[Kevin Camp]

i wondered how one might go about creating whole pixel movement for a film and also having that movement work for when scaled down to a dvd… and the only thing i could think of was figuring out an increment for the film rez that could be divisible by the scale factor…

1556 / 480 = 3.241667

lets just call it 3.25 (although it wouldn’t quite be accurate and it may cause problems later). you would need a film rez movement of 13 pixels per frame. 13 / 3.25 = 4, so your scaled down version would be 4 pixels per frame.

unfortunately i don’t have ae at home to try this (i’ll test it tomorrow), but i’m not sure how it will work with a pulldown added to the d1 24p.

i think the best solution would be to create one for film and another for dvd.

[Steve Roberts]

Well, use the MPEG-2 preset with VBR that gives you the highest data rate, yet still allows your movie to fit on the DVD.

I’ve tried tweaking MPEG-2 settings in MegaPeg Pro (a compressor), and found that tweaking tends to allow me to fit more material on disc while *maintaining* untweaked quality, rather than *increasing* untweaked quality. I’m back to Compressor now, because my work is very short and it does well enough for me. I might go back to MegaPeg for longer projects.

For more info, you should post in the DVDAuthoring COW or the Compression techniques COW. Maybe DVD first …?

[Sam Moulton]

definitely interlacing issues here

Attended a class by Chris Meyer…
Here’s the drill.. Different formats require different speed. The difference between 24fps and 23.976 with pull down means you credit roll will have to be different speeds for the two projects in order to be perfect.

I’d suggest you get it perfect at 24fps for your film out, render that, then bring the render back into AE, scale it to fit into your NTSC comp, re-interpret the footage to 23.976 fps and render out without fields. This will fix the interlacing issues.

[Kevin Camp]

i think i agree, you need two rates… my 13 pixel move idea does work to create whole pixel move in the 2k and the dv, however the move is too fast, so it appears jerky, and it still looks awful when you add pulldown.

i think a major issue is the pulldown, they way interlacing has to be generated using even lines from the frame in front and odd lines from the frame behind seems to be a real problem. going 24p for d1 would help… do you need to put the d1 to tape? is it necessary to interlace to bring the piece up to 29.97?

does anyone know how they get movie credits to 29.97 for dvd/tape and avoid this problem? do they create a new rate for the credits?

Kevin Camp
Designer – KCPQ, KMYQ & KRCW

[Ecourtney]

Hey Kevin,

Thanks for your reply. The feedback I’ve gotten from the DI folks is that it is common these days to have the same credit roll for film and video. There used to be a problem with this a few years back that would require the credits to be re-timed, but there is supposed to be a solution that allows one credit roll to work for both. I just can’t find it…

Erik

[Kevin Camp]

while waiting on approval of some print projects, i figured ou a way to get whole pixel movement for both the 2k and the d1/dv that is much smoother than the 13 pixel move.

instead of using the 3.25 scale factor, cheat and use 4. you’ll need to decide what sd resolution (480 or 486), but then just multiply that by 4 to ge the comp size for the credit roll. so if you wanted to go with dvd 720×480, then the credit roll comp would need to be 1920 high (keep the 2k width, 2048px).

for the credit roll move, you will need to make the move a multiple of 4 to keep the movement to whole pixels for both the film version and the video version. i used this expression:

rate = 8;
x = position.value[0];
y = position.value[1] – ((time / thisComp.frameDuration) * rate);
[x, y]

where ‘rate’ is the number of pixels (remember it needs to be a multiple of 4). if the sd version needs to be field friendly, then it must be a multiple of 8 (note, that this is only true for true interlaced, not 24p witha pulldown).

once the rate is established in the 2048×1920 ‘credit roll’ comp, just drag that comp into a 2k preset comp. now your credit roll is ready for film.

take that same ‘credit roll’ comp you just dragged to the 2k comp and drag it into a 720×480 comp. scale the layer to 25%. now it will run in sd.

this method still won’t work in 24p with a pulldown, i’m not sure that there is any way to make int work with a pulldown. you can however, get it to work in 29.97 interlaced.

just duplicate the ‘credit roll’ comp and change the frame rate to 29.97. make sure the ‘rate’ of the move is set to a multple of 8. then drag the new credit roll comp to a dv preset comp and scale the ‘credit roll’ layer to 25%. when rendered with fields, the move will be smooth.

Kevin Camp
Designer – KCPQ, KMYQ & KRCW