Mixing frame rates AND resolutions

S

sean90291

Veteran
If I have a 59.94 HDV sequence, and a 23.976 DV sequence, and I want to end up with a single sequence which combines both of these sequences, what's the best route?

Going up to DNxHD for all? Or down to DV for all?

Going up to 30i for all? Or down to 23.976 for all?

A conundrum. For me at least.
 
You're always going to be better off downrezzing than uprezzing. There's plenty you can throw away in the HD(V) footage to make it work at DV resolution, but trying to go DV -> HD(V) isn't going to look very good. Think of it as stretching out a kid-size T-shirt to fit a 350-pound fat dude. Sure, it'll work--but it ain't gonna look good.

Frame rate is a different question altogether, but I think that as you surmised, going into a 30i sequence (Avid calls it 30i instead of 60i, which to my mind is a misnomer--but I digress) is going to be the solution. Before I go any further, though--is your HDV footage progressive or interlaced? That's going to make a difference... I think...
 
Thanks cb. Good advice. I'll down-rez to the lowest common denominator.

And I guess I'll have to convert the 23.976 to 30 or the 30i to 23.976i. Have to look into that one. I usually don't go in that direction! Any tips?

HDV footage is interlaced. It was captured in progressive by the sensor, but becomes interlaced when the camera puts it to tape. It has not had the pulldown done to it, because that is a whole ordeal with HV20 footage unless you have one of Cineform's products. I might get the Cineform Neo HDV. Just I'm a bit reluctant to but it when I won't be using the HV20 much longer.

Cheers.

EDIT: MichaelP has provided a neat step-by-step for using Avid's FluidFilm to convert interlaced 30i (29.97) footage to progressive 24fps (23.976) footage here

http://www.24p.com/conversion.htm

I'm not yet sure how to get that converted sequence into another project. I'll give it a try. But I'm thinking that even with FluidFilm applied, if the project is a 59.97 project, then I can't just open that bin in the 23.976 project. Or can I. I'll try. Maybe I have to export it as a QuickTime movie and then re-import into the 23.976 project.
 
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I think a 480/30i project is going to be your best bet to make everything mesh. Here's why:

1) Your HDV stuff is interlaced. Yeah, looks progressive, but as you described, the footage as recorded is interlaced. You can simply open the bin containing your 1080/59.94i sequence in your 480/30i project, and you'll be able to playback and/or transcode to DV there.

2) Your 24p DV stuff is progressive, so that won't go nicely into your 480/30i project, either by opening the bin or trying to import a QT ref of your 24p sequence. It'll throw up mismatched frame rate errors. However, you should be able to lay off your 24p sequence to DV tape, which is going to add pulldown, and then you could recapture that tape into your 480/30i sequence.

I was going to post the link to that "conversion" document at 24p.com--glad you found it. I don't see a preset for taking 23.976p media and turning it into 29.97i media though, but I guess if you were feeling daring, you could convert your transcoded HDV sequence (in your 480/30i project) into 23.976p and import that into your original 23.976p project.

Also, as you surmised, you'd have to render out a QuickTime in order to make the FluidFilm effects apply. It creates new media with the speed change.

Post back on your results--I might actually be trying something like this shortly!
 
Yes, I did have to export a QuickTime reference file of the HV20 footage with the Fluidfilm effect applied (using MichaelP's suggested settings: 125% speed, interlaced input to progressive output) in order to get that HDV footage into a DV 23.976 Avid timeline. I then just re-imported the QuickTime reference file into the 23.976 timeline and it looks good to my eye.
 
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