50i to NTSC 29.97P or NTSC 24P?

Robert W wrote on 11/17/2008, 5:56 PM
I'm just about to sign off on a project shot in 50i that I've prepared for NTSC playback. Just for ease of use and compatibility I prepared it as NTSC 29.97P. However, I am now wondering, is 29.97P a standard format? Should I render to 24P with 3:2 pulldown, or whatever it is called?

To be honest at this stage I am not hugely concerned with squeezing the best possible quality. I am happy with the quality of the conversion at 29.97P. Converting from 50 HD interlaced fields to 29.97 progressive fields is certainly a lot better than going from 50 PAL interlaced fields. It looks very smooth. All I am concerned about is ensuring compatibility.

Any guidance?

Comments

farss wrote on 11/17/2008, 6:26 PM
as far as I know all that will happen is that your 30p ends up as 60i or to be technical, 30PsF. All that means is each frame is split into two fields for compatibility.

I've done a bit of 50i to 60i using Vegas, looked pretty good to me and the client. Looking at it frame by frame I could see what an expensive standards converter would have avoided but you really have to look hard.

Bob.
Robert W wrote on 11/17/2008, 6:29 PM
So can the fact that it is on disc as NTSC 29.97P cause an issue? Because it is definitely rendered progressive, the interlacing will take place in the player.
farss wrote on 11/17/2008, 6:37 PM
Is this a SD or HD DVD?

Either way if DVDA accepts it you should be OK. I know Piotr created a 25p BD disk and it played just fine even though the BD spec doesn't mention 25p.
Yes, as far as I know the player will split the fields.
If in doubt you can just render it to 60i in Vegas and encode that, no real loss involved.

Bob.
kairosmatt wrote on 11/17/2008, 6:41 PM
Are there any problems with going from 50i to 24p?

I think that DVfilmaker can convert PAL to 24p, but am not sure if the results are good.

Does anyone have any experience with this?

thanks
kairosmatt
farss wrote on 11/17/2008, 7:03 PM
Unless you've got lots of fast motion then just use Vegas.
Use Mike Crash's Smart De-interlacer to get 25p.
The use Vegas to change the frame rate to 24fps by slowing it down ~4%. If you do this right no interpolation involved.
Job done.

Bob.
kairosmatt wrote on 11/17/2008, 7:56 PM
Thanks Bob
kairosmatt wrote on 11/24/2008, 7:42 AM
I have the smart Mike Crash's de-interlacer installed and I apply it to the event as a Video FX.

1. Do I need to change any of the FX settings?

2. I can't find a readme or help file for this plugin or on Mike Crash's site-does anybody know where I can find an explanation for all the options?

thanks
kairosmatt
kairosmatt wrote on 11/24/2008, 8:02 PM
Just so I know I'm doing this right, here's my process for bringing in 50i to a 23.97 timeline:

1. Put the clip on the timeline
2. Add Mike Crash's smart de-interlacer, using the frame only differencing preset.
3. Right click on event and go to properties
4. Disable resample
5. Set playback to: .959

Is this right?

The media that I have does not have very much motion, but I am having trouble seeing exactly what the de-interlacer does., or what frame vs field differencing does.

Any feedback would be great!
Thanks
kairosmatt