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Looking for input on shooting/editing resolution/frame rate

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Drew SmithLooking for input on shooting/editing resolution/frame rate
by on Sep 25, 2012 at 4:59:36 am

Hi there, wasn't sure where to post my question, hopefully this is a suitable forum!

I am working on a doc film that was shot with a Panasonic HDX 900 camera. I was originally under the impression that we shot in 1080i/23.98p (I didn't actually work with the shooting, only post). After the edit and work done at the post house somehow we have ended up with 1080i video at 29.97i??

I'm new to shooting in HD so am still trying to wrap my head around all the different resolution and frame rate options as well as how they're handled in editing/post. (We're editing in FCP 7)

We had hoped to produce Blu-rays in 1080p but now unless we use an interlace filter we're looking at 1080i due to combing.

My questions are the following:

1. Is it even possible to output a 1080p resolution disc from video shot in 1080i/23.98p or any other progressive frame rate?

2. Any ideas where we could have gone wrong losing the progressive frame rate? Capture/edit/render?

3. Am I hopelessly lost in the confusing land of HD resolutions and frame rates, never to return??

Thanks for any feedback!


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Walter SoykaRe: Looking for input on shooting/editing resolution/frame rate
by on Sep 25, 2012 at 10:40:25 am

[Drew Smith] "I was originally under the impression that we shot in 1080i/23.98p (I didn't actually work with the shooting, only post). After the edit and work done at the post house somehow we have ended up with 1080i video at 29.97i?? "

You keep saying "1080i" even when talking about progressive frame rates. You can have 1080p23.976, or you can have 1080i29.97, but "1080i23.976p" is meaningless.

Since this is an After Effects forum, if you import the raw footage into Ae, what frame rate does it report in the project panel when you highlight the footage?


[Drew Smith] "1. Is it even possible to output a 1080p resolution disc from video shot in 1080i/23.98p or any other progressive frame rate?"

Yes, Blu-Ray supports progressive frame rates.


[Drew Smith] "2. Any ideas where we could have gone wrong losing the progressive frame rate? Capture/edit/render?"

You can step through your 1080i29.97 footage one frame at a time, looking for a pulldown cadence. If you see three clear frames followed by two mixed frames, the video was shot in 24p. If you see four unique frames followed by two identical frames, the video was shot in 24p.

In either case, talk to your post house and find out what happened. It's possible that they did the edit in 24p and gave you a 1080i29.97 master with pulldown. It's also possible that they converted all the footage from 24p to 29.97i on ingest. The first situation would be good news, but the second situation would be bad news. Of course, the third and most likely possibility is that you shot at least partially in 29.97i so they preserved that frame rate through the edit.

Walter Soyka
Principal & Designer at Keen Live
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
RenderBreak Blog - What I'm thinking when my workstation's thinking
Creative Cow Forum Host: Live & Stage Events


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Drew SmithRe: Looking for input on shooting/editing resolution/frame rate
by on Sep 25, 2012 at 2:43:06 pm

Walter, thanks for your reply!

I guess the best place to start (and maybe I'll post ove rin the Panasonic forum too) is with how the Panasonic HDX 900 shoots. It's my understanding that it doesn't shoot in "True 1080p" rather it is a modified interlaced stream with a progressive framerate.

Just came across this on another post, it's from a while back but sounds similar to my issue:

"[Neal Broffman] "...I was asked by a client to shoot some material on a Panasonic HDX900 set to 1080 24p 1/48th... the client has now come back and said the material was shot in 1080 59.94 not 24p and that they had to spend significant time dubbing to "correct" the problem..."

If it was 1080 footage, it was INTERLACED. Only the most expensive cameras on the planet can shoot true 1080p, and aPanasonic HDX900 doesn't qualify as such. Thus, your camera recorded 29.97 interlaced-frame video, and to get to an actual 23.976 frame rate, you have to remove the 3:2 pulldown.

Either the client screwed up by not knowing this little factoid... or you did."

The way I understand how the Panasonic camera shoots is that it has a progressive sensor and records the frame rate progressively but but the final recording is effectively interlaced as there's not single frames, rather two identical fields that are "interlaced" Not sure if that is a correct understanding, someone please correct me if I'm off on this...


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Walter SoykaRe: Looking for input on shooting/editing resolution/frame rate
by on Sep 25, 2012 at 2:55:47 pm

[Drew Smith] "The way I understand how the Panasonic camera shoots is that it has a progressive sensor and records the frame rate progressively but but the final recording is effectively interlaced as there's not single frames, rather two identical fields that are "interlaced" Not sure if that is a correct understanding, someone please correct me if I'm off on this..."

See the Wikipedia article on 2:3 pulldown [link] for a detailed explanation.

If your post house failed to remove pulldown before beginning editorial, that's a pretty grave mistake.

I participated in a thread a couple years ago about how to remove pulldown after editorial [link]. (That thread was a follow-up to this original [link], which also contains a lot of good information.

Walter Soyka
Principal & Designer at Keen Live
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
RenderBreak Blog - What I'm thinking when my workstation's thinking
Creative Cow Forum Host: Live & Stage Events


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Drew SmithRe: Looking for input on shooting/editing resolution/frame rate
by on Sep 25, 2012 at 10:44:26 pm

Hmm, thanks for the info. Getting hard to wrap my head around all this!! I'll check into that further.

To confirm, Panasonic lists on their site that the Panasonic HDX900 shoots in the following 1080 resolutions:

Multi-format recording system that supports 1080 at 59.94i, 50i, 29.97p, 25p, 23.98p, 23.98pA

So if my understanding is correct, 1080 at 23.98p fps =1080p but they also state that the camera shoots 1080i or 720p.

Thus my 1080i 23.98p resolution that's missing. Is my logic correct here?


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Walter SoykaRe: Looking for input on shooting/editing resolution/frame rate
by on Sep 26, 2012 at 12:59:23 am

The i in these formats indicates interlacing. The p indicates progressive. There is no such format as 1080i 23.976p.

24p can be wrapped in 29.97i by adding 2:3 pulldown, so 24p frames ABCD are mapped to 29..97 fields as AA BB BC CD DD -- one frame goes to 2 fields, then the next goes to 3 fields. To remove the pulldown and return to 24p, you mus combine one field from the third frame with the other field from the fourth frame.

24pA adds 2:3:3:2 pulldown to wrap 23.976p into 29.97i without creating mixed frames. Thus, ABCD beccomes AA BB BC CC DD. To remove the pulldown (going back to 24p), the mixed frame is simply dropped.

If you have some specific questions on the theory, I can answer them, but if you have specific questions about your actual footage, you'll have to post some or ask your editor.

Walter Soyka
Principal & Designer at Keen Live
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
RenderBreak Blog - What I'm thinking when my workstation's thinking
Creative Cow Forum Host: Live & Stage Events


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Drew SmithRe: Looking for input on shooting/editing resolution/frame rate
by on Sep 26, 2012 at 1:52:47 am

Thanks for your help Walter! I appreciate you attempting to walk me through this.

In reading back through the thread, I just want to make sure that you're clear about what the issue is. We have our final cut in 1080i that looks and plays perfectly (I understand that this would eliminate the concern that the pulldown wasn't removed?). The issue is that I was told (and expecting) that the footage would be 1080p as we're outputting to Blu-ray. When the grand plan was originally explained to me it was indicated that we had shot progressively. Soooooooo....

In talking with our cinematographer and director, I think we've discovered where the miscommunication and ultimately unexpected interlaced final movie has stemmed from. They shot the film in 1080 at a progressive framerate in order to give it a film look, however the used an interlaced image. (Still not sure I understand how the camera specs indicate that it can only capture in 1080i or 720p but lists progressive frame rates for 1080??) Anyway, they indicated that they had always planned on 1080i but shot with a progressive framerate for the look. Not sure this makes sense to me but maybe make sense to you?

Anyway, it is what it is and we'll deal with it.

If things were more clear at the start, would it have been possible to finish with a 1080p version of the film that was shot on the HDX900? I suppose this would have had to be clear to the editor from the start?

If the plan from the start is to output to DVD/Blu-ray would shooting in progressive or interlaced make more sense?

Thanks again for your help!


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Walter SoykaRe: Looking for input on shooting/editing resolution/frame rate
by on Sep 26, 2012 at 1:54:33 pm

[Drew Smith] "In reading back through the thread, I just want to make sure that you're clear about what the issue is. We have our final cut in 1080i that looks and plays perfectly (I understand that this would eliminate the concern that the pulldown wasn't removed?)."

If you shot 24p or 24pA and edited in 29.97i, you very likely have broken cadence (meaning that the consistent pattern of 2 fields of one frame followed by 3 fields of another has been disrupted). It may look ok to the eye, but it is not perfect and may be rejected by distributors on technical grounds.


[Drew Smith] "They shot the film in 1080 at a progressive framerate in order to give it a film look, however the used an interlaced image. (Still not sure I understand how the camera specs indicate that it can only capture in 1080i or 720p but lists progressive frame rates for 1080??) Anyway, they indicated that they had always planned on 1080i but shot with a progressive framerate for the look. Not sure this makes sense to me but maybe make sense to you?"

The HDX900 shoots DVCPRO, and while the camera's sensor can operate progressively, the DVCPRO tape system only supports interlaced material. To get progressive imagery onto an interlaced tape format, the camera adds pulldown as it records.

If you want progressive output, and if you shot in "24p mode" with standard 2:3 pulldown, you must capture from tape as 29.97i, then remove pulldown on each clip in Cinema Tools before editing.

If you want progressive output, and if you shot in "24pA mode" with 2:3:3:2 advanced pulldown, applications like FCP can remove the pulldown during capture (see Working with 24p DVCPRO HD [link] in the FCP docs for more.

If you shot 24p, you want to edit 24p so you can deliver 24p. You can also deliver from 24p to 29.97i by adding pulldown to the finished sequence.

If you shot 24p but edited at 29.97i, then there is no way to guarantee that the program has a consistent 2:3 or 2:3:3:2 pulldown, and cleanly deriving a progressive master from the edit is going to be difficult.


[Drew Smith] "If things were more clear at the start, would it have been possible to finish with a 1080p version of the film that was shot on the HDX900? I suppose this would have had to be clear to the editor from the start?"

Yes, if you want a specific deliverable like 1080p23.976, you should make that clear at the start.

However, in my opinion, if the footage was either 24p with pulldown or 24pA, the editor should have noticed and not proceeded with a 29.97i edit.


[Drew Smith] "If the plan from the start is to output to DVD/Blu-ray would shooting in progressive or interlaced make more sense?"

Either progressive or interlaced could work. If you specifically wanted 24 frames per second, then all post-production should have been progressive.

Walter Soyka
Principal & Designer at Keen Live
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
RenderBreak Blog - What I'm thinking when my workstation's thinking
Creative Cow Forum Host: Live & Stage Events


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Drew SmithRe: Looking for input on shooting/editing resolution/frame rate
by on Sep 26, 2012 at 5:36:24 pm

Ok, at least I feel like I'm getting somewhere from an understanding standpoint. It's not fixing our issues but at least I can learn from mistakes or oversights.

Revisiting some of your earlier comments:

You can step through your 1080i29.97 footage one frame at a time, looking for a pulldown cadence. If you see three clear frames followed by two mixed frames, the video was shot in 24p. If you see four unique frames followed by two identical frames, the video was shot in 24p.

In either case, talk to your post house and find out what happened. It's possible that they did the edit in 24p and gave you a 1080i29.97 master with pulldown. It's also possible that they converted all the footage from 24p to 29.97i on ingest. The first situation would be good news, but the second situation would be bad news. Of course, the third and most likely possibility is that you shot at least partially in 29.97i so they preserved that frame rate through the edit.


I think a bit of confusion is stemming from the fact that we had a person doing the edit in FCP and then took the film to a post house to have the final grade/sound done so there have been a number of cooks in the kitchen.

I did step through the final version of the video from FCP before it went to the post house(the version before it went for final grade)and it did have a pattern of three unique frames followed by two identical frames (I assume that these are the mixed frames?)

The info in FCP for the video file:
Frame: 29.97
Compressor: DVCPro HD 1080i60

I'm not sure what this means though. Is there any way of finding out what the first edit was done in, before it went to the post house? (24p or 29.97i?)(Our editor is away right now)

Still trying to figure out where exactly things got mixed up.


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Walter SoykaRe: Looking for input on shooting/editing resolution/frame rate
by on Sep 26, 2012 at 6:21:15 pm

[Drew Smith] "I did step through the final version of the video from FCP before it went to the post house(the version before it went for final grade)and it did have a pattern of three unique frames followed by two identical frames (I assume that these are the mixed frames?)"

That indicates a 2:2:2:4 pulldown, where ABCD becomes AA BB CC DD DD. This can happen when you have true 24p material in a 29.97i timeline in FCP.

Do you have access to any of the original captures from the camera to observe the cadence there?


[Drew Smith] "It's not fixing our issues but at least I can learn from mistakes or oversights."

You can fix your issues with the methods I outlined in the one of the threads I linked to. You can have Compressor try to remove irregular pulldown (this will be hard over dissolves or effects), or you can go back to copies of the original footage files, remove pulldown, translate EDLs from timebase 30 to timebase 24, and reconform.

Walter Soyka
Principal & Designer at Keen Live
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
RenderBreak Blog - What I'm thinking when my workstation's thinking
Creative Cow Forum Host: Live & Stage Events


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Drew SmithRe: Looking for input on shooting/editing resolution/frame rate
by on Sep 26, 2012 at 8:22:47 pm

Hmm, I'll see if I can dig up the original captures.

The issue with fixing things is that our final version is through post color/grade which we spent a lot of money on. If we go back to original footage files and reconform, I suspect we'd have to do the grade again?

It does appear that somehow footage may have been shot in one framerate and edited in another.


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Walter SoykaRe: Looking for input on shooting/editing resolution/frame rate
by on Sep 26, 2012 at 8:45:17 pm

If you really only have duplicated frames (2:2:2:4), you can try to fix the final. The first thing you have to do is figure out where the pulldown was added. If the pattern is consistent throughout the final movie, across all cuts (meaning the pulldown was added on output), then you can simply decimate every fifth frame to get from 1080i29.97 to 1080p23.976. If the pattern is inconsistent, you'd have to do frame duplication detection, which could get very tricky over dissolves and effects.


[Drew Smith] "The issue with fixing things is that our final version is through post color/grade which we spent a lot of money on. If we go back to original footage files and reconform, I suspect we'd have to do the grade again?"

Talk to your colorist. They may be able to reconform without regrading (but they would have to re-render).

Walter Soyka
Principal & Designer at Keen Live
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
RenderBreak Blog - What I'm thinking when my workstation's thinking
Creative Cow Forum Host: Live & Stage Events


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Drew SmithRe: Looking for input on shooting/editing resolution/frame rate
by on Sep 26, 2012 at 10:31:09 pm

Ok, so I just checked the final version of the video that we got from the post house. It has the three normal frames and two (mixed?) frames (two frames where you can see some combing on a computer monitor) pattern.

Will have to check other versions of the files...I'll keep you posted.

Thanks again for your help!!


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Drew SmithRe: Looking for input on shooting/editing resolution/frame rate
by on Sep 27, 2012 at 4:46:10 pm

Ok, I finally got my hands on some of the original captured footage as well as the final Apple ProRes file that was given to us by the post house.

Both have a cadence of three normal frames followed by to frames that seem to have combined fields (combing) Is this pulldown?

The strange thing is that I also have a QT version of the film that we used for a test screening and it has the previously mentioned 2:2:2:4 pulldown. Not sure how that happened.

Thoughts?


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