deinterlaced output is not deinterlaced

Steve Mullen wrote:

Now I'll recheck my 720p output.

Steve, allow me to guess the outcome.
----720p (h264) from im08 will look just fine.

Try the same thing with 1080i source through QT pro only.

Steve Mullen wrote:
In the iM08 viewer, I see motion blur but no combing. But, from my lines photo I see All lines. To my eyes it is using one field of video and downscaling to window, but i scaling down all lines of photo.

Photos don't have interlaced fields so no reason to single field there. And iM08 doesn't single field all videos, but only when it thinks something is interlaced.

http://av.watch.impress.co.jp/docs/20070926/fullhd.mp4

Linked above is a 1920x1080 60i mp4 footage from Xacti HD1000. It is interlaced video, but somehow the 'flag' is not visible to iMovie08 and it doesn't do single field. If you bring it into iMovie08 you'll notice the badly squeezed interlaced pattern. (At least that's how it was when I tried it on iM08 and QT 7.55 before upgrading)

To my eyes, iM08 is behaving exactly as it should with interlace video.

iM08 was a lot more mindful of this interlacing issue. It forces single field processing during editing and with the right setting exports interlaced video.

iM09 however acts as if it doesn't know what interlaced video is. It always treats it as a full frame video and applied whatever resizing and manipulation as it would to a progressive footage. So I can't use any cropping with 1080i footage. Image stabilization won't like it either because the analyzer will be only more confused by these tooth lines, not knowing that they represent different time of the video.(So far I'm seeing better stabilization on 960x540 videos) You get to see the full frame in iM09 viewer and full screen, but often with badly squeezed interlace. And it is easier to output back to 1080i because at no point iM09 forces single field, but then again resizing to 720p yields a very bad result.

The best way to deal with interlaced source, in my opinion, is to acknowledge the two fields and when it comes the time to manipulate the frame, treat each field as a separate frames of 60p footage and perform resize, crop, image stabilization analysis and weave them back to 60i internally. (Which is how visual effects are often done with interlaced video.) But I think that it may not be practical to do in all realtime yet and iM08's singlefield compromise is perhaps the better solution.

At first I thought iM09 finally gave us full frame ability, but now it looks more like it doesn't care about 1080i video. At least it should have an option to turn on single field or, even better deinterlace, when it needs to perform any operation that can damage the interlaced footage.

But overall it is not iMovie or Apple's fault. Interlaced video is just plain painful for any kind of image manipulation, and iMovie09 just gave up on it completely. 😟

PS: how did you include photos?

I upload photo somewhere and use this tag.

img src="photo URL"

and surround it with the angular parenthesis.

Not Apple's fault? Disagree here. If it worked in '08 then it should work in '09. If it works from FCP, then it should work in '09. It's got little to do with what's better between 60i or 30p...and I agree that 30p is better.

I will be shooting at 30p going forward but to brush off the possibility that there's a bug/issue to be addressed does us no favors.

fincher wrote:
Not Apple's fault? Disagree here. If it worked in '08 then it should work in '09. If it works from FCP, then it should work in '09. It's got little to do with what's better between 60i or 30p...and I agree that 30p is better.

I will be shooting at 30p going forward but to brush off the possibility that there's a bug/issue to be addressed does us no favors.

When I said it's not apple's fault I meant how nasty interlaced video is for manipulation, by its nature. iMovie08's system sort of works, but you still lose quality if you want to do any resizing operation and it was hard to get full 1080i unless you know the right setting.(which I found out thanks to the folks of this board.) Most of the time you lose half the Vres whether necessary or not.
It was better because the quality loss wasn't as bad as 09's sawtooth ugliness, but it doesn't change the fact that interlaced video is pain in the neck for post processing.

Now, if you are shooting 30p all the time, iM09 is much much better for you because it'll treat your video as a true 30p progressive video and bypass the interlace flag. 30p videos from camcorders are still recorded with 60i format so you would've lost Vres unnecessarily in iM08. That doesn't happen at all with iMovie09.

Those who want to use 1080 60i with iM09 are in more hairy situation. Straight cutting should be fine, but if you want to resize in anyway, like cropping or export to 720p, you are screwed. iM09 unfortunately doesn't adaptively deinterlace or singlefield when necessary.

This is how I view it. iMovie08's system works for 80% of the time, but also 80% of the users probably sacrifices vertical resolution. iMovie09 works 100% for 30p and 60i without quality loss, but if you want to export 720p or crop, it is 0% for 60i.

The compromise is unavoidable as long as the source video is interlaced, we may or may not agree with Apple on where to place it. Perhaps it is because 720p just got very useful for Youtube HD.

Agreed on interlaced being a pain in the neck but Apple made it work in '08 so why not '09?

Thing is, I have about a dozen events from 2008 shot at 1920x1080 at 60i. I have no issues with how I've used it so far, which is for iPhones, the web at 960x540, etc. Eventually, I will want to export out at full HD when I have an easy means to view it at full HD. And, what about others who are not yet aware of this issue? Using a third-party de-interlacer is a last resort for me.

The fact that 60i looks fine when exported at the stock sizes provided by iMovie '09 simply leads me to believe that Apple will address this issue of how it's now exported via QT.

Lastly, this is iMovie, a great consumer-level application...I'm just a Dad doing my job of handling the video of my kids' events. If this program is going to output 60i at full HD with obvious issues, then Apple either needs to fix it or advise users of the perils of shooting HD at 60i and recommend using 30p. Either way, this needs to be addressed.

Winston, I'm exporting to AIC. And, you are correct it does look fine, BUT:

I added a scrolling title to part of my video clip and to part of the stills to see if adaptive de-interlacing was being used.

1) Direct export to 720p from iM08 -- VIDEO had motion blur with no combing or mice teeth. The lack of combing tells me weave deinterlcing was not used. For the stills, ALL lines were visible which tells me bob deinterlcing wasn't used.

The only option left seems to be field-blend deinterlcing. As I understand this, a new frame is constructed by running a weighted kernel down a frame holding both odd and even lines. This makes sense because I believe a frame is what iM08 provides to the QT exporter. (It is also what I think is used inside iM08 when you playback video.)

Scrolling title looked fine and made no change to background video -- so adaptive wasn't used.

This 720p looked very good.

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2) Export 1080i from iM08 with JES used to convert to 720p -- VIDEO had motion blur with no combing or mice teeth. The lack of combing tells me weave deinterlcing was not used. For the stills ALL lines were visible which tells me bob deinterlcing wasn't used.

In area near scrolling title, the background video lost lines because mode switched to bob. This is expected from JES using Region Adaptive Deinterlacing.

So what does JES use in the regions without motion. Because of the lack of combing and the visibility of all lines -- I've got to conclude that field-blend deinterlcing was used.

Yet, I can see no difference between the BOTH FIELDS and BLEND FIELDS options. Which is odd because I would assume BOTH is weave while BLEND is field-blend.

Anyway, this 720p also looked very good.

As far as I can tell -- iM08 and QT 7.3.1 are working perfectly.

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Looking on the web -- I saw two pix of what iM09 users are seeing.

http://www.100fps.com/

The first example looks like the mice teeth you guys see. The second example has the mice theeth where there are unequal heights. No explanation is given for the difference. But, both are claimed to be examples of what happens if video is "resized before deinterlacing."

What does this mean?

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Euisung -- I'm confused. You seem to say there is some advantage to iM09 because it treats 1080i as "progressive" by ignoring the interface flag.

1) Here is YOUR list of things that can't be done with 1080i in iM09: "So I can't use any cropping with 1080i footage. Image stabilization won't like it either because the analyzer will be only more confused by these tooth lines, not knowing that they represent different time of the video. (So far I'm seeing better stabilization on 960x540 videos). You get to see the full frame in iM09 viewer and full screen, but often with badly squeezed interlace."

THAT"S A LONG LIST OF FAILURES IN 09!

2) YOU say that with 08 "... you still lose quality if you want to do any resizing operation and it was hard to get full 1080i unless you know the right setting. First, I don't see why quality will be lost.

Anyway, I can't think of any reason to re-size 1920x1080 video since it is the largest frame-size that can go to BD. (I might up-scale 720p to 1920x1080, but this should be OK.)

Second, most of us already knows to use the UPPER setting -- so "fixing" this is no big deal. Apple could have simply posted a nice note here. 🙂

Third, we can get great 720p exports from 09 but not 08.

So what are the advantages of the new design in 09?

Winston Churchill wrote:

So in conclusion, iMovie uses both fields and never discards a field anymore...

I'm not sure we can say that...

Winston,
I still need to try out different output options but as for 'no more single field operation' I may be wrong. It is quite strange that my iMovie09 viewing window sometimes shows full frame and sometimes singlefielded one.

iMovie was showing this before

and now it shows no interlaced fields or the effect of it, meaning it's in single field mode. But it's only for the display.

Output is the same. I always end up with interlaced fields regardless of codec, as long as I choose upper 1080 setting. I always get ugly sawtooth with 720p. Cropped footage shows messed up field lines.


Part of clip that 'cropping' is applied. Ugly...

When I choose 960x540 size (export to QT), iMovie doesn't drop one field but combines the two.

This is 960x540 output. Two fields averaged to one shows the ghosting we see from deinteraced footage. This doesn't happen when one field is dropped.


Cropped footage in 960x540. Ouch...

I tried Export to movie - large (960x540) and I get the same result as above.

I still think iMovie09 doesn't use single field processing for output, but perhaps during editing for display purpose. And from my tests so far I think the codec only can affect whether the end movie has field dominance flagged or not, but I may be missing something here.

Message was edited by: Euisung Lee

"So far I have only seen this behaviour when using imovie 09 and QT Pro itself."

So for you, iM09 and QT Pro give the same bad results using QT 7.5.5 when they use the MOV container.


Curiou if when you checked QT Pro -- did you import a movie exported from iM09 or exported from FCP?

If from 09, then we are back to the CA thing. I can't believe QT can't make MOVs from something exported by FCP.

In other words, if iM09 is the first Apple application to export with the CA flag set -- perhaps when it calls the QT API or when you move a iM09 export file to QT Pro -- AND try to make a MOV file, something gets scrambled. As long as iM09 does the export all is well.

PS 1: I'm not saying iM09 is the first to set the CLEAN frame-size. Obviously, it's not. I'm saying that perhaps iM09 may be the first to try to force QT to honor CLASSIC or CLEAN when it makes a MOV.

If this is the case, Apple may have shipped iM09 knowing that there will be a QT 7.6.1 that will fix this. (I assume you have tried QT 7.6.)

PS 2: I'm not sure I buy that iM09 ignores interlace. It seems to me that because of PIP and stabelization it would be important for iM09 to keep track of interlace. That would allow it do correctly scale (for PIP) and deinterlace while anylizing video for stableization.

Frankly, I have always believed 08 never keeps track of interlace. It drops a field for SD. 540p and 720 aren't interlaced. And, when 1080i is exported to 720p is simply assumes the top field is dominant.

fincher wrote:
Agreed on interlaced being a pain in the neck but Apple made it work in '08 so why not '09?

Thing is, I have about a dozen events from 2008 shot at 1920x1080 at 60i. I have no issues with how I've used it so far, which is for iPhones, the web at 960x540, etc. Eventually, I will want to export out at full HD when I have an easy means to view it at full HD. And, what about others who are not yet aware of this issue? Using a third-party de-interlacer is a last resort for me.

I wouldn't know why apple made 09 this way but perhaps it's because of the complaints and feedback about single field processing. It is very simple and easy way to dodge the whole interlaced video problem, but I guess people - me included - didn't like that iMovie was making that choice for me.

But, that was when I didn't know that there was a way to export full 1080i from iM08. (The upper 1080 and such...) Now that cancelled out great deal of my complaints about single field limit, and here is iMovie09 that feels a bit like a slap in the face to the other direction. (full frame editing? take it!)

I agree that Apple needs to revisit this issue and address it, hopefully soon.

Is the 640 x 480 SD video from digital still cameras generally 480p or 480i?

I get pretty good sd quality video from my canon s5is and would like to know if there will be any issues like those above when editing in imovie 09?

Thanks.

Steve Mullen wrote:
THAT"S A LONG LIST OF FAILURES IN 09!

Indeed. And I add one more - the crucial one - to the list. Stabilization with 60i is completely out of question. Stabilization, which inevitably scales the video up, yields horrible result.


iM09 export without stabilization


iM09 export with stabilization. About 115% stabilization zoom.

Stabilizing 60i video correctly is more complex (60i->60p to analyze), and Apple didn't bother to go that far. So iMovie09 seems to be determined to be done with 60i. (But it's in love with 30p. ) It is as if Apple thinks that nobody really uses 60i HD with iMovie.

2) YOU say that with 08 "... you still lose quality if you want to do any resizing operation and it was hard to get full 1080i unless you know the right setting. First, I don't see why quality will be lost.

If you crop your video in 08 and export 1080i you end up with the same garbage as 09.


This is cropped 1080i in iMovie08 exported with upper HD size. iMovie08 doesn't selectively deinterlace/singlefield the 1080i either within edit. Had iM08 had stabilization feature it would've been unusable for 60i as well.

It does singlefield the source for output so you get nicer 720p output from 60i. But, if you want to make 720p from 1080 30p source you'd unnecessarily lose Vres. (1080->540->720)
You'll have to export it to 1080p and re-export to 720p outside iM08 to get best result.

Anyway, I can't think of any reason to re-size 1920x1080 video since it is the largest frame-size that can go to BD. (I might up-scale 720p to 1920x1080, but this should be OK.)

I agree. But resizing within editing is another issue. Cropping and stabilization both scales the video up, and even a slight resizing ruins interlaced video. Neither iM08 or 09 is smart enough to deinterlace for those operations. So, don't use crop with 60i in iM08, and don't use crop and stabilization with 60i in iM09. (doh!)

Second, most of us already knows to use the UPPER setting -- so "fixing" this is no big deal. Apple could have simply posted a nice note here. 🙂

I was away from this forum for quite a bit and I had no idea. I don't think this is well publicized fact yet for most users. Apple should post a note in their opening home page!! 😉

Third, we can get great 720p exports from 09 but not 08.

I assume you meant better 720p from 08, and not 09. I wouldn't say it is 'great' 720p, because of the resolution loss I mentioned. But it sure beats 09's teeth.

So what are the advantages of the new design in 09?

I wouldn't say there is advantage at all for 60i. But when it comes to 30p, which more camcorders are supporting, iMovie09 has upperhand because the way 09 will ignore the interlace flag of 60i container and treats 30p as is. 30p in 09 will never face a danger of single field processing.

Considering that 30p hasn't really taken off and majority of us has to still deal with 60i, iMovie09 is very unkind and needs fixing. Apple liked to dictate which technology or format users should use - "Either shoot 30p, or ingest 60i to 960x540". And ironically I hate Sony more who insisted on interlaced video for HD!!! 😉

Steve Mullen wrote:

As far as I can tell -- iM08 and QT 7.3.1 are working perfectly.

Now that's interesting. I wasn't aware of any such issues in im08 either, as for QT I had the impression you were using 7.5.x.

I'm using 7.6 and have an issue, someone else was using 7.5.x and had the same issue in QT but not in im08.

Euisung Lee wrote:
I still need to try out different output options but as for 'no more single field operation' I may be wrong. It is quite strange that my iMovie09 viewing window sometimes shows full frame and sometimes singlefielded one.

I got to the stage after using im09 for a while trying different exports and all that, that it started to do strange things, I guess a good nights sleep and a shut down solved that. I note the im09 browser is quite strange any way. Resize it and I get different results. Drag it to resize it and you can actually see it changing as you drag it.

Output is the same. I always end up with interlaced fields regardless of codec, as long as I choose upper 1080 setting. I always get ugly sawtooth with 720p.

Are you sure about this, it isn't my experience. (I'm assuming you are talking about im09 here)

Firstly, I see no difference between using the upper and lower setting except that lower is flagged to display as cropped. The upper setting (1920 x 1080 HD) exports with a classic aperture flag, the lower setting (HD 1920 x 1080 16:9) exports with a clean aperture flag, but you can toggle this in QT back to classic and then it should look the same as the upper setting.

Also check to confirm the output is interlaced, I don't believe it is, it just looks like it is. Drop the export into something like Media Info and it reports progressive, check deinterlace or single field in QT properties and it does nothing (as you'd expect with progressive)

When I choose 960x540 size (export to QT), iMovie doesn't drop one field but combines the two.
This is 960x540 output. Two fields averaged to one shows the ghosting we see from deinteraced footage. This doesn't happen when one field is dropped.

Can I confirm this was 'export to QT' from im09, when I choose 'export to QT' and set the resolution to 540 from im09 I don't get any such ghosting just combing.

Are you saying that when you export to movie in im09 you get ghosting (indicating deinterlacing has taken place)

My 08 tests show no loss of resolution going to 720p from 1080i other than from the inherent loss from field-blending during deinterlace. And, since there's no reason to crop 1080i -- the potential loss of quality isn't a real loss in quality. So, other than missing Precision trim -- there's not a big reason to move to 09. Why?

If you shoot 1080i -- which is by the the largest majority of HD video -- and try to use two of the new features in 09 -- PIP and stableization -- you are will get awful quality. I'll bet green screen does look that great either with 1080i.

While Winston offers hope it's a QT type bug that could be fixed, Euisung seems to feel that Apple is simply being consistent. It makes do difference if you shoot SD or HD. Apple with SD forces the video to progressive by dropping fields. With HD, Apple seems to offer the option of 1080i -- but you'll quickly figure-out that only 960x540 works.

This is consistent with their you can't tell the difference between FullHD and QTRHD. Frankly, I think they are going to push their own HD format -- 540p. It will be the HD used on the iPhone and iPod, along with ATV. (Yes, I think Apple will go after Sony and Panasonic with an HD iPhone because for kids this is the perfect camcorder. In fact, for many folks it will be perfect.)

Now I must confess that I have my own anti-1080i view. Except for one camcorder, since the introduction of HDV, I've shot only 720p. (And, I really want to shoot 720p60.) My objection to 960x540 is it is not a format supported anywhere but Apple products, So although 09 will work fine for me -- I am getting worried about the way Apple is moving. For example, I'll be soon be working with a JVC camcorder that shoots 720p60. Were JVC to release a consumer version -- I'd be dead in the water with iM.

With other companies I might have to wait for support. But, with Apple it's now clear they will ONLY support stuff they sell. BD is the perfect example.

PS: Can you keep 08 when you install 09?

Steve Mullen wrote:

PS: Can you keep 08 when you install 09?

Yes