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Weird problem. Has anyone seen this before?

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Manuel Sclavo
Weird problem. Has anyone seen this before?
on Mar 26, 2015 at 7:04:01 pm

Hi, I'm having a weird problem with Premiere that's driving me crazy and I can't find much information about it online.

Here is an image to help me illustrate the problem better.
idkwtfigo.jpg (take a look at it at full res or you won't notice it).
It seems like the fields are messed up, but only at the borders, specially if there's high contrast.
It's also different depending on the zoom level I have inside the project.
I'm puzzled.
I have tried changing fields, editing mode and renderer with no success.
Also tried exporting to several different formats but the problem is still there.

All the footage is AVCHD (.mts) which I know Premiere hates but has worked for me in the past.
Video drivers are up to date (even tried reverting to an older driver).

Any ideas would be appreciated.

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Ht Davis
Re: Weird problem. Has anyone seen this before?
on Mar 26, 2015 at 8:22:16 pm

Was the footage originally shot in progressive mode?
It seems the fields are indeed a little messed up, and that's related to Adobe's interpolation of the MTS. Most MTS will be read as 30i or 30p, even if it was shot at 60fps in progressive mode. You have to blow up the mts into an intermediate file with a readable header that fixes the issue. I use AME to blow up the files into prores or avc intra. IF your client doesn't know how it was shot, you could use AME to output multiple files in tandem, including proxy versions (i'd set up each different frame count as a separate job with 2 outputs, so as one finishes you can check it right away). It looks like at least half the frames were dropped and half the fields are missing. What's your preview mode? What type of screen? What is the refresh rate in your monitor\screen driver set to (50hz? 60hz? etc). If you play a 25i video on a 60hz screen, you can sometimes see artifacts during playback; same for 50i. You can also see it going 60i on a 50hz screen. The frames are refreshing at a different rate than your screen, so interlacing will be a problem. One way to combat the problem is to set the field mode for editing to Progressive, and have your video decompress to progressive frames in AME using the Frame blending setting. Usually, you'll have to match your Client's output needs for your sequence, so you should set the frame rate the same, but the field mode to progressive. If you can get their field mode settings, then you can export with that later, and turn off frame blending so it will drop the unused fields.

But seriously, it looks like your sequence is at a different rate than your video. MTS doesn't have an adobe readable header (so it guesses). Try an AVCINTRA file, and then auto create a sequence from that clip.

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Manuel Sclavo
Re: Weird problem. Has anyone seen this before?
on Mar 26, 2015 at 8:35:06 pm

Thanks for your reply :)
I'm out of the office now but I'll work around your advice tomorrow and report back.

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Ht Davis
Re: Weird problem. Has anyone seen this before?
on Mar 26, 2015 at 11:08:06 pm

Was this an iPhone video?
Was image stabilize on?
This creates Variable frame rate, and with interlaced material, you can drop fields. Use AME to fix by decompress to file, and turn on Frame Blending in the settings for the transcode. Only other problem I can think of that would cause this.

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Manuel Sclavo
Re: Weird problem. Has anyone seen this before?
on Mar 27, 2015 at 1:20:03 pm

[Ht Davis] "Was this an iPhone video?"
Footage was shot with a proper video camara, not a photographic camera nor a phone. It was a Panasonic I'm not sure about the model though.

[Ht Davis] "Was image stabilize on?"
Possibly. I have no way to know since the footage is a couple of years old and the people who shot it don't work here anymore.

[Ht Davis] "Was the footage originally shot in progressive mode?"
I ran it through MediaInfo and it says it's interlaced with upper field first.
Here is the whole info in case something else might be relevant.

ID : 4113 (0x1011)
Menu ID : 1 (0x1)
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4.0
Format settings, CABAC : Yes
Format settings, ReFrames : 2 frames
Format settings, GOP : M=3, N=12
Codec ID : 27
Duration : 16mn 46s
Bit rate mode : Variable
Bit rate : 20.3 Mbps
Maximum bit rate : 21.6 Mbps
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate : 25.000 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Interlaced
Scan order : Top Field First
Bits/(Pixel*Frame) : 0.391
Stream size : 2.37 GiB (94%)

And fixed !! :)
I had the sequence set to progressive fields, changed it to upper first and it worked.
I'm pretty sure I had already tried this, but who knows... maybe I'm dumb and only tried Lower Field First.

Thanks a lot HT

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Ht Davis
Re: Weird problem. Has anyone seen this before?
on Mar 28, 2015 at 8:04:21 pm

I figured it was something to do with the fields not lining up and running out of sync. I'll make a note of this in a text doc and hang on to that one. Thanks for the update and info.

Even "Proper" cameras have an image stabilizer anymore, they just aren't in use (turned off) or they get filtered through a frame reduction (going from 60fps to 30fps/24 to feel more TV like, to reduce the "Too Sharp" or REALITY effect). Panasonic, Canon etc, all have an OIS, IS, or EIS system.

1. OIS is an optical effect created by dropping frames when the camera sensor detects camera shake at the outer edges of the frame, and requiring a Blending of frames later, or an Interpret footage step in premiere. Other editors do this by default, and give their best guess, but premiere assumes you want to control that yourself. AME allows you to give a best guess by turning on frame blending in a transcode or decompression step.

2. IS is usually attached to the lens. The technology in basic IS is similar to that of the military standard sniper rifle. The lens "floats" so that it doesn't move as fast as the camera shake, and is gently stabilized without affecting the frame rate, and keeping the output file intact. This is a professional method, but most pro cameras still allow you to turn on OIS as a secondary measure.

3. EIS has two flavors. This happens after the image is taken, where it is processed into compression. If a set of frames shows too much motion at the outer edges, frames will be dropped. Some cameras actually have a feature where the frames are dropped and replacements are blended with heavy blur to add the effect of defocusing the image during the motion, adding a feel of hype and "racing heart" emotion, but this also has limitations for the speeds it can work at.

My last bit of advice:
If you have a video where you know the base frame rate, and want to work in a certain mode, but know nothing else about the video, you can always Transcode it to something you want to work with. I usually make at least 3 files, and compare them; all prores 422 in lower end projects, going from full 422 to 422LT to 422Proxy. I use the proxy during my edits, but I check if the LT file is "Good Enough" and then decide if I want the full freight file for use in output or just the LT. IF motion is a little unnatural, I use the full file, but add a motion blur, adding a short effect render just before output so I can check it.
If I have a file that is in an interlace, but I need to go to full digital output (youtube\vimeo etc), which is all the time anymore, I simply Dupe the sequence, Cut everything out (storing it in a buffer), then change the fields in the dupe to progressive, paste everything back in, select the clips and replace with a progressive field version I make in AME with frame blending on. This results in (for me) noticeable quality in some of the shorter motion areas, while keeping image fidelity.

I edit and AME with a 2008 macbook pro with 2.16ghz cpu, 4gb ram, 2x 1tb hdd's, 256mb vram and currently latest mavericks system (yosemite is latest osx, but I held off because much of the software will lose compatibility and I don't want to fight that just yet). I compress with compressor batches, but I have it send to one or more machines when I rent out a studio of them for compression rendering. IF I use AE for an effect, I use the AE renders on big machines and farm it if possible, then have it render to video using AME on my macbook, storing the file in prores locally for movement to my working directory. It works pretty fast, assures I've got copies of everything, and I wipe it after burning archives to discs and producing final output. Editing with a slower processing unit forces better habits when it comes to workflow, plus, I can farm out what I need to any way I like, while keeping some previews of my recent work for showing off a little.
If you have another problem, shoot me a message or post here, copy the link to an email:

I'm an old pc\mac troubleshooter, and I've recently been doing video editing. I'm on the Adobe forums or these later at night (in the am portion of the night in my time zone; pacific).
I keep notes on problems like this to save time trying to troubleshoot. I pulled up a few of those with a search and gave you what I'd already found based on the description of the problem. Text is small and easy to store on an old flash drive, and easier still to keep a backup image stored in several places.

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Manuel Sclavo
Re: Weird problem. Has anyone seen this before?
on Mar 30, 2015 at 12:44:04 pm

Thanks for the insight.
I'll be sure to use that method next time those nasty AVCHD get messed up.

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