deinterlaced output is not deinterlaced

"This is how clean aperture should work normally. The source video is not touched. No rescaling, just cutting out the edge of the frame."

1) It looks like it's not necessary to actually crop the video -- just provide the desired clean frame size.

But, if cropping is done without re-scaling, monitors that show the full frame will have black borders. Like those that can be created by JES. I assumed the rescale prevented the bands around the pix. Maybe that's what Apple was trying to do. Or, maybe it's a bug.

In any case, the point is to not use anything but the upper two options and never request a deinterlace. Then it doesn't matter if Apple fixes anything.


2) In one sense, it makes sense that any inter-frame codec based video is converted to intra-frame (AIC). But, since the slo-down rule is either "repeat 2 times" or "repeat 3 times"-- I can't see why this isn't a real-time decision as video is decoded. Likewise, for speed-up. Skip every other frame.

Only reverse might need to be decoded to a file since the content must be played backwards. Sometimes I think Apple just does iLife as a quick and dirty demo.

Was the 24p video in a 30fps Project or in a 25fps Project?


PS: this is from the QT 7.1 documentation:

Clean. Conformed tracks are cropped to the clean aperture mode and scaled according to the pixel aspect ratio. This is the new default for consumer applications.

However, since PAR = 1.0, there is no rescale.

Steve Mullen wrote:
But, if cropping is done without re-scaling, monitors that show the full frame will have black borders. Like those that can be created by JES. I assumed the rescale prevented the bands around the pix.

I do get border when I play movie with clean aperture on on 1920x1200 monitor and unlike computer monitors HDTV doesn't show the full 1920x1080 picture but the cropped part (safe zone). This is suppose to cut out edge that potentially has noises and stuff you don't want to show. Actually many consumer HD camcorders' viewfinder shows this cropped area.

Was the 24p video in a 30fps Project or in a 25fps Project?

Original poster was using it on NTSC project, I think. I tested it in both NTSC and PAL project and both required conversion. 23.98p movie was fine without conversion, so I think it's related to NTSC/PAL engine. Quicktime Player can do slowmo/fastmo on any movie, but iMovie is clearly not using the same function here.

PS: this is from the QT 7.1 documentation:

Clean. Conformed tracks are cropped to the clean aperture mode and scaled according to the pixel aspect ratio. This is the new default for consumer applications.

However, since PAR = 1.0, there is no rescale.

Yes, horizontal expanding is for anamorphic movies. 1440x1080 source movies with flag on is expaned to 1920x1080 and cropped back to 1880x1062, but it's a flag for playback. Exporting a movie with flag setting on shouldn't apply any resize to the source.

The fact that they mentioned this is default for consumer apps makes me think that apple added this to prevent consumer confusion when they see more picture on computer but less on HDTV.

This problem has now been blogged about by Chris Breen over at Macworld.com

See here:
http://www.macworld.com/article/139124/2009/03/export720pimovie09.html?lsrc=rss_ main

"Movie pulls up 24p (23.98) movies to 25p in PAL project by adding dummy frames. When exported to 23.98 fps iMovie does remove those dummy frames and gives you clean 23.98fps movies with no duplicate dummy frames.

But here is tricky part. Output to 23.98 is only possible when your iMovie setting is in NTSC. Doing so under PAL rounds it up to 24.04 even if you set it to exactly 23.98 or 23.976 in output fps setting. So here's what I do with true 23.98 movies.

1 Set the iMovie Video Preference to PAL.
2 Create a new project (this will stay PAL, even if you switch back to NTSC)
3 Do editing /stabilization and all
4 Switch iMovie back to NTSC
5 Export to Quicktime (with 23.98 fps) "

Sounds right, but:

1) How do you get 24p into iM09? Mine refuses to import.

2) Stabilization can't be used. Correct?

3) What's the issue with 24.0fps and 30.0fps video?

Steve Mullen wrote:
1) How do you get 24p into iM09? Mine refuses to import.

I only have HV20 which is 24p in 60i, so I import it as 60i and inverse telecine with JES. iMovie at least recognizes converted 24p movies in the event folder. I don't know about direct import of true 24p footage from cameras, which I think iMovie doesn't support.

2) Stabilization can't be used. Correct?

It can be used with 23.98fps movies although the result in NTSC project gives you a slightly weird look. It seems to work better in PAL project. At least it allows it without conversion.

3) What's the issue with 24.0fps and 30.0fps video?

I don't know the answer to that. All I know is that iMovie wouldn't stabilize the footage unless the movie is 29.97 or 23.98 fps, which leads me to think that it has to be precisely NTSC compatible.

" iMovie at least recognizes converted 24p movies in the event folder. I don't know about direct import of true 24p footage from cameras, which I think iMovie doesn't support."

Correct -- it says NO to import from camera. But, you say it will Import from file. Correct?

"It seems to work better in PAL project. At least it allows it without conversion."

So importing 23.98 into PAL works. Good.

"What's the issue with 24.0fps and 30.0fps video?
I don't know the answer to that. All I know is that iMovie wouldn't stabilize the footage unless the movie is 29.97 or 23.98 fps, which leads me to think that it has to be precisely NTSC compatible."

But what about 25fps and 23.98 in a PAL 25fps Project? Are you saying even 25fps video is converted to NTSC for stabilization?

I would assume as long as I use 25fps Projects, until export all will be well. Correct?

How did you get 23.98 out of the 30fps Project?

Steve Mullen wrote:
Correct -- it says NO to import from camera. But, you say it will Import from file. Correct?

I don't know. AVCHD in 23.98 mts file may not import.

"It seems to work better in PAL project. At least it allows it without conversion."

So importing 23.98 into PAL works. Good.

What I said is about stabilization, not importing. I don't know if iMovie imports 23.98 footage under PAL setting but I doubt it. What I meant is that stabilizing 23.98 footage in PAL project yields better result compared to NTSC project.

"What's the issue with 24.0fps and 30.0fps video?
I don't know the answer to that. All I know is that iMovie wouldn't stabilize the footage unless the movie is 29.97 or 23.98 fps, which leads me to think that it has to be precisely NTSC compatible."

But what about 25fps and 23.98 in a PAL 25fps Project? Are you saying even 25fps video is converted to NTSC for stabilization?

No. 25fps should work because it conforms to PAL. I think your footage needs to be compatible with either PAL or NTSC for stabilization to work. In case of 24 and 30, they are in NTSC land so they need to be in 23.98 and 29.97 to work.

I would assume as long as I use 25fps Projects, until export all will be well. Correct?

I think so.

How did you get 23.98 out of the 30fps Project?

Just specify output QT's fps to 23.98. It doesn't have to be NTSC project, but *iMovie video preference* needs to be set to NTSC for it work. Your project will remain PAL if it's created under PAL setting.

" I don't know if iMovie imports 23.98 footage under PAL setting but I doubt it. What I meant is that stabilizing 23.98 footage in PAL project yields better result compared to NTSC project. "

How did you get 23.98 into a PAL project to test stabilization if you didn't import it into the Project?

Are you saying you imported into 30fps and then switched to 25fps?

I think you are correct, 23.98 AVCHD is going to be refused by iM09. Which means AVCHD would have to be batch converted to AIC or ProRes 422. Don't know if there is a utility to do this.

XDCAM EX is imported fine IF converted to ProRes 422.

Seems like true 24p is just too much trouble.

Just when we thought iM09 could import and export 1080i with no problem -- turns out there is a hitch.

My camera can record 1920x1080i on h.264/aic. Edited in iM09 and exported at 1080i using ProRes 422 -- there is NO combing on movement when played by QT player. The video is frame-blended. Bad.

Convert the h.264/aic clip to ProRes 422 -- import and export as 1080i. There is combing. Good.

This behavior is not new to me. Take interlace DV and convert to M-JPEG -- iM will not export as interlaced video. Take the same DV and convert to interlace AIC -- now iM exports as interlace video.

However, iM can be tricked. Place an interlace AIC clip as the first clip in a Project and now the M-JPEG can be exported as interlaced DV.

So I tried the same trick with an interlace ProRes clip as the first clip. Now the h.264/aic clips are output as interlaced.

Which makes me wonder about AVCHD.

Steve Mullen wrote:
How did you get 23.98 into a PAL project to test stabilization if you didn't import it into the Project?

My footage is JES inverse telecined 24p. Once placed in iMovie Events folder and they are recognized and usable by iMovie. So if you can get your 24p AVCHD converted to 24p Quicktime somehow, you should be able to use them in iMovie.

Seems like true 24p is just too much trouble.

I wish it wasn't, but unfortunately so :-/

So you aren't working with AVCHD?

Steve Mullen wrote:
So you aren't working with AVCHD?

No. I don't own a AVCHD camera. I may, if I end up buying Panasonic GH1! 😉

Me too!

UPDATE

Seems the h.264/avc does -- as others have reported -- have an issue with interlace video.

A camera can encode interlace video. When you play in the QT Player you'll see combing on motion.

But, once in iMovie, it is treated as one-field video. Not progressive and not interlaced.

The reverse problem happens in FCP. If one exports interlace to h.264 or x.264 -- the result is treated by the QT Player as progressive. You'll see combing. You can click One Field and nothing happens. The combing remains.

-------------

So avoid cameras that can record 1080i using h.264/avc if you are using iM09.

Do not try to export interlace to h.264/avc.

--------------

PS: My trick of putting an interlace clip in a Project does not work! Sorry.

This thread is being locked and is continued in deinterlaced output is not deinterlaced (continued). The thread was getting too long and some browsers were timing out.

Thank you,

Apple Discussions Staff