Trying to Fix Clip Distortion in Premeire Pro Caused by Vertical Flip

[dzahorsky]

So I make video works specifically using a method of 'quilting' clips together e.g. cropping, then mirroring horizontally and vertically until they make one seamless clip. The problem is that often when I do this after a clip is flipped, usually always vertically a line of what looks like static appears on the bottom or side of the clip and no matter what I do I can't ever get rid of it. What I've done in the past is layered them so the clips that are less altered are on top and thus hide the distortion, or opening the clips up by themselves in MPEG Streamclip and cropping the portion that is distorted but this doesn't always work and can often cut out valuable parts of the subject. Both these also feel like bandaid fixes and I'm hoping someone who knows I'm sure WAY much more than I might have an idea or a solution.

Thanks in advance.

[poisondeathray]

Can you post a screenshot of what the "line of static" looks like? It might be "normal" because (obviously) not all content is seamless / "tileable", or perhaps it's "normal" from compression artifacts

Perhaps your source material has problems to begin with (perhaps noisy borders, perhaps interlaced material - you have to be careful about how that is handeld). Did you try on known clean progressive clips?

Or perhaps that you've cropped by an "illegal" number for that colorspace ?

Eitherway, you need to provide more information

An alternative way to do these manipulations is in avisynth with flipvertical, fliphorizontal, and/or stackvertical, stackhorizontal and similar commands

[Cornucopia]

I'm guessing these are digitized analog videos, which contain head-switching noise - those will have to either be masked, or cropped (and resized?).

Scott

[dzahorsky]

Sorry, I should have included a screenshot here it is. Sometimes it's colored line like the blue you see, other times it's flashing white like static, it's also been both green and red.

I have tried on clean progressive clips and nearly always get the same result. I don't always crop and the line appears regardless of cropping. It is almost always specific to vertical flipping and very less like for horizontal, I don't know why. I understand more information would be ideal, and I totally understand if it is quite literally the things that prevents me from being able to fix it, I know just enough to be dangerous.

[smrpix]

Does it clear up if you change your resolution from 1/2 to full? (Next to the wrench icon at the lower right of the screen.). It may be a preview aliasing artifact.

[dzahorsky]

No from 1/4 to full resolution there is no change, and when the clip itself looks pixelated at 1/4 the line still looks crisp, as if it's on top of the footage if that makes sense.

[newpball]

So I make video works specifically using a method of 'quilting' clips together e.g. cropping, then mirroring horizontally and vertically until they make one seamless clip. The problem is that often when I do this after a clip is flipped, usually always vertically a line of what looks like static appears on the bottom or side of the clip and no matter what I do I can't ever get rid of it. What I've done in the past is layered them so the clips that are less altered are on top and thus hide the distortion, or opening the clips up by themselves in MPEG Streamclip and cropping the portion that is distorted but this doesn't always work and can often cut out valuable parts of the subject. Both these also feel like bandaid fixes and I'm hoping someone who knows I'm sure WAY much more than I might have an idea or a solution.

Thanks in advance.

Hmm, I do not seem to be able to reproduce, what is the source and what CODEC is used?

[Cornucopia]

"flashing white" I would have thought VITC timecode, but if you have tried cropping to no avail, that couldn't be it...

Doesn't get to the root of the problem, but what I'd do is layer a "cover strip" above the seam point. Like lettterboxing/pillarboxing, but much thinner and maybe with faded/transparent edges. Then you might have a boxy, modrian-esque, wild-wild-west look to it, but at least you won't have something visible that you don't want to be visible.

Scott

[dzahorsky]

So the central concern of this is to quilt all of these variations of the same clip together to achieve a seamless piece of work, I think for masking/letter boxing every variation would need to be done and then exported as a new clip so when they were put together they would adjoin and this adds a tremendous amount of time to even a single few seconds, I'm not afraid of the work but am hoping to find a way to streamline the process.

Also the source encoding is Linear PCM shot on a canon D60 that save as quicktime .mov [defaults as I work on a mac]
the export is H.264 with a bitrate of 10 - Sequence setting DSLR 1080 @ 25FPS [but I've experimented with other sequence settings to no effect]

[newpball]

Could you attach a few seconds of video? (If there are rights issues just fill the whole frame with black all the way up to but not including the edges).

[dzahorsky]

No worries, here it is

[newpball]

Right that is the vid after processing, but do you have a clip before so then I will try to reproduce it on my machine and see if I can figure out what is going on.

[dzahorsky]

Touche. Give me a sec, I don't like the upload platform here, I'll share a dropbox link to the file.

[dzahorsky]

Raw Footage: Was imported into DSLR 1080 @ 25FPS, freeform rotated 90 degrees clockwise and then copied. Copies were subsequently flipped vertically and/or horizontally

https://www.dropbox.com/s/zd73d6weg2z1fpg/MVI_0521.MOV?dl=0

[poisondeathray]

But even on the "after" video, it's odd that the line distortions come and go frame or so. What is the relevance with respect to the timing ? What else are you doing, what effects etc...

But I think it's no coincidence that the bottom left isn't aligned (it's cropped morethe right edge compared to the video above it), and that's the one that has the issue for the most part

It can't be only rotation and flipping, otherwise they would align better. You must be doing something else

Outline the entire workflow step by step, and exactly what programs and manipulations you are doing. You mentioned mpegstreamclip, but are you doing everything in premiere ?

[dzahorsky]

Alright,

As far as i know there is no relevance to the timing, truth be told the workflow contains little alterations.

1. All clips are imported from DSLR to Iphoto when I use mac or straight from DSLR to folder on PC [I tried PC to see if it was a mac import issue - no change]
2. A new Project is started in Premeire CC - clips imported and new sequence created: DSLR 1080 25FPS
3. clips are brought onto timeline [Now for this particular clip the footage was first cropped from the top, then rotated 90% Clockwise then copied and flipped both horizontal and/vertical and that's it. There are fade in and fade outs on various clips and some are sped up but not the one you see here, none of that has seemed to have any effect. In past works I would crop with MPEG but I've done none of that for this last project - the one relevant to the footage above everything was done in premier, I think I used AE one time to do some dust removal but exported to the same clip settings so that should have no affect and was a different clip anyway]
4. sequence is exported to H.264 [Vimeo 1080 customized settings] @ 25 FPS with bit rate of 10

So on this last film I layered them so you couldn't see it, on the link below look at timestamp 5:41

https://vimeo.com/105910099

However in the current work I'm wanting to use more clips and I can only hide so many, and so am looking for a more permanent solution

[poisondeathray]

I have a suspicion that if transcode them to prores first before anything else, that your worries will go away

[dzahorsky]

I'm going to be honest, I don't know much about this, I've heard about this workflow before, it sounds like a pretty intensive process and I've been afraid of botching it, kind of like when you keep painting even though you've passed the point at which you understood what you were painting and you wind up with a hot mess.

My understanding is that you need to download the presets, install them in prelude and then ingest your clips and then I have no idea if they export into 'proress' etc does this sound even remotely correct? And feel free not to answer I've taken up a lot of everyone's time and I'm super grateful for it.

[poisondeathray]

First, this shouldn't be happening at all. I can't replicate these types of errors and I've dealt natively with DSLR footage for years, at least on a PC version of Premiere and other programs. I've done these types of manipulations before, and many more

My suspicions are odd cropping values, and perhaps some issues with h264 . You can get weird edge artifacts when you crop 4:2:0 material by odd values, but internally that shouldn't be happening because it's upsampled before the cropping occurs.

When in doubt on a mac, especially with h264 DSLR footage, you use prores (when buggy issues occur on a PC you encode to something else too). You can batch encode the clips in Adobe Media Encoder, or mpegstreamclip. Use google there are lots of step by step tutorials. Basically, prores is golden on a mac. It takes a lot more HDD space, but everything becomes smoother and consistent when you edit and manipulate

[dzahorsky]

I appreciate that, I'll look into prores, thanks for putting it in definitive terms.

[dzahorsky]

Oh man I got really excited about that. But NO DICE!

Used MPEG Streamclip to encode the clip from H.264 to Proress 422, brought it into premiere. Cropped, rotated, and then the RUB vertically flipped it and the line came right back.

And here's the interesting thing, when I crop it, though the actual footage crops the line stays with the original frame, could this mean anything?

[poisondeathray]

And here's the interesting thing, when I crop it, though the actual footage crops the line stays with the original frame, could this mean anything?

So despite cropping, the line defect is there? What if you don't crop at all? Is vertical flip the sole determining factor? SO if you don't flip at all, are there any problems ?

I don't know what it means. If it was a static line for the duration of the clip (not on/off seemingly randomly in your exported clip ), it might suggest something, but the pattern suggests something else.

I don't know what is going on, sorry. And I cannot replicate these types of errors either

[dzahorsky]

Correct, whether I crop it or not is of no consequence, this is uncropped but flipped. And no worries, I'll keep experimenting and hopefully stumble onto a solution eventually, thanks for all your help!

[poisondeathray]

Use mediainfo (view=>text) on the DSLR original, and the Prores version. What is the reported height ?

In premiere, what does it "think" the height is for both ?

Most Canon DSLR's actually store it at 1920x1088 (yes, 1088) , most programs and decoders obey the "crop frame" flag (it's a flag in the bitstream that says discard the bottom 8 pixels to return 1080 ) . Perhaps something is going on with that ? I'm just throwing out wild guess now, because I really have no idea

[dzahorsky]

On both they say = original height 1088 but for height read 1088

[budwzr]

The unwanted edge anomaly almost looks like the rotation is off one pixel, but there's no pixelation (stairstep).

In Vegas, it's fine:

[Cornucopia]

@dzahorsky, I think you mis-quoted the screencap you posted: it says Height 1080, Original Height 1088, Width 1920.

So, I'm betting money on pdr's assessment of fallback to original height when rotating/flipping. Which really ought to be considered a bug and flagged.

...Although, a conversion to 1920x1080 ProRes should NOT encounter that feature, as it shouldn't have a problem with non-mod16 sizes. Hmmm...

I'd go with having pre-processed (rotated, flipped) versions (via AVISynth), so there is NO rotation/flipping going on WITHIN PPro itself. If that segment is avoided, I'll bet the rest works perfectly fine.

Scott

[budwzr]

I say it's a bug in Premiere.

[smrpix]

I say it's a bug in Premiere.

I dunno, the original clip works fine here even when rotated, resized and put into a mis-matched framerate sequence (as OP has done.) There's something else going on here.

[budwzr]

Hmmm...Ope is on a Mac though.