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-   -   program to convert 30p to 60p (https://www.dvinfo.net/forum/jvc-gy-hd-series-camera-systems/52030-program-convert-30p-60p.html)

Thomas Smet September 30th, 2005 04:44 PM

program to convert 30p to 60p
 
I am trying to get some feedback from people.

One of the only downsides in my opinion to the HD100 is the lack of 60 frame motion recording such as 60p or 60i.

I have been thinking of looking into making a program to convert 30p to 60p video for those who need 60p broadcast video projects.

This will be fairly slow so I wouldn't want to use this on wedding footage but it would be great for 30 second spots.

It would use motion tracking to actually create new in between frames or you could dumb down the quality by making the new frames just blended versions.

I'm not sure how much of a interest there would be in something like this. At first I thought it would be really great but the more I test it and think about it the more I see that being limited to 30p isn't really that big of a deal. Unless you plan on mastering to DVCPROHD tape the 60p would be kind of useless in any other format.

Steve Mullen September 30th, 2005 05:20 PM

Simply shoot in 480p60 HDV. It is a great option for those not needing a 1280x720 rez image.

Tim Dashwood September 30th, 2005 06:00 PM

With FCP, just drop the 30P sequence into a 60P sequence, then render and output. You could turn frame blending on or off.

Barry Green September 30th, 2005 08:37 PM

I'd have to second the notion of shooting 480/60p SD and then up-rezzing it. That's more likely to look better than synthesized motion between frames, wouldn't it?

Douglas Spotted Eagle September 30th, 2005 09:19 PM

Quote:

Originally Posted by Barry Green
I'd have to second the notion of shooting 480/60p SD and then up-rezzing it. That's more likely to look better than synthesized motion between frames, wouldn't it?

Just did an uprez of 60p to 720 in two jumps, and it looks very, very nice. Brian Mercer, a moderator of another forum, does a lot of this sort of work and has some really smooth methods that are pretty good, so long as there is good contrast in the image.

Thomas Smet September 30th, 2005 09:37 PM

Well shooting 480p 60p is still SD resolution. Uprezzing it to 720p and saying it looks pretty good is like saying 30p from a DVX100 looks just as good as 720p 30p.

The thing with the method I was going to use is the type of slow motion rendering where perfect or close to it frames are created. Instead of slow motion however it only does this to make frames in between the real frames. So every other frame would be exactly as it was before. With 30p each frame is shown twice inside of 60p. What I was thinking of doing is creating the in between frame that would look 90% as close as it would if it were shot at 60p.

Frame 1=real,2=interpolated,3=real,4=interpolated,5=real. You should have the exact same level of quality as before except your motion will be a little bit smoother.

Some programs when converting 30p to 60p would end up interpolating every frame. Frame blending would work but it isn't perfect. If you watched your video frame by frame or paused on an even frame you would notice the blending. During playback you can also get a slight shimmy similar to what the motion smoothing looks like.

Since nobody seems to be interested I guess I will scrap this project and move on to my other stuff. I figured with some of the complaints I was hearing about the lack of 60p I would come up with a solution but nevermind.

Tommy James October 1st, 2005 09:47 AM

I think that upconverting the footage from 720p30 to720p60 is a great idea because shooting in 720p to start with gives you the option to upconvert to 1080p which is not possible if you shoot 480p. Since I am assuming that the bandwidth will be doubled from 19 megabits ber secound to 38 megabits per secound would a conventional 16X Data DVD be able to stream at this rate ?
Also is there an 720p60 MPEG2 encoder program for a laptop computer so that the 60 frames per secound can be recorded from the JVC HD100 so that the camera operator would not have to be tethered but could carry a laptop in his backpack ?

David Newman October 1st, 2005 11:26 AM

"Also is there an 720p60 MPEG2 encoder program for a laptop computer so that the 60 frames per secound can be recorded from the JVC HD100 so that the camera operator would not have to be tethered but could carry a laptop in his backpack ?"

720p60 can only be directly captured from the analog component output. The full 720p60 signal is there. We have a Prospect HD how has just started capture 720o60 directly into CineForm Intermediate using an AJA YPrPb to HDSDI adaptor. Which is pretty cool.

Back on subject : interpolating 60 from 30 is very difficult for high quality, but it has its applications so I'm interested to see your progress.

Steve Mullen October 1st, 2005 03:27 PM

Now that we see how well JVC's Motion Filter eliminates strobbing on 30p recording, I've been wondering if some smart person could write a program that decoded 30p (from an HD10) and used the MPEG motion vectors to create intermediate frames. Now there would be 60fps that could be output at 720p60.

Clearly, abrupt motion changes wouldn't be handled well, but most constant motion might be handled corrrectly.

Giroud Francois October 2nd, 2005 04:27 AM

you do not need to write anything, it already exists as mentionned.
all slow motion plugins are doing the same job , creating in-between frames.
in this case we just need to create 1 in-between frame that should be easy.

motionperfect is a well known product that works well for such use.
http://www.dynapel.com/products/mp_overview.shtml

in this example,at the extreme, between each frame, 19 frames have been interpolated.
http://www.dynapel.com/videos/VideoE...ace20x_sbs.mpg

another one that support HD for sure
http://www.realviz.com/products/rtpro/index.php

and for free, you can use virtualdub and the many plugins, like the ones that are deinterlacing (producing 2 p frames out of 2 i frames).

Tim Baker October 2nd, 2005 01:57 PM

Confused on this whole posting thread
 
I guess maybe I do not have enough experience with my HD100 yet, but why don't you just shoot in the HDV0-SD60P mode?

I did this at a local football game the other night to test the camera with fast motion sports and it looks great and it stays in a 16x9 screen ration.

John Mitchell October 3rd, 2005 08:42 AM

Quote:

Originally Posted by Tim Baker
I guess maybe I do not have enough experience with my HD100 yet, but why don't you just shoot in the HDV0-SD60P mode?

I did this at a local football game the other night to test the camera with fast motion sports and it looks great and it stays in a 16x9 screen ration.

I think the idea was to shoot in HD not SD.

Frame interpolation using motion vector smoothing - Boris RED will do this for instance as part of it's feature set, (as well as other more sophisiticated products like Realviz, Avid DS and Symphony etc ) could be effective, but these are generally used for slowing down existing footage rather than the situation Thomas called for.

I imagine to achieve this you need to slow the footage down to 50% then interpret the resultant clip as 60P to have it play at the correct speed.

You can only try it and see if it yields a better result than 480P60 uprezzed. Usually with motion vector smoothing (rather than straight frame interpolation) to achieve the best result you have to limit the interpolation to the fast moving areas of the picture otherwise your static areas can be adversely affected by the algorithm.


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