Vertical stripes of video shifted / displaced sideways in regular pattern

[JonathanCMH]

Hello!

I'm wondering if anyone has had this happen, possible causes, and anything that fixes it? Does it have a technical name? My searches using a description haven't brought up anything really relevant or useful.

All through the video clip there are narrow, parallel vertical lines of shifted video. The lines aren't black... instead, the lines are material from the video image but shifted to the right in a regular, parallel, vertical pattern. They're in the same place on every frame.

I've thought of using multiple overlays of the same clip to sort of stitch together a composite, but if there's a less time consuming option, I'd be interested.

[jagabo]

Those are probably decompression errors. Try using a different codec for decompression.

[JonathanCMH]

Thanks jagabo,

It's MTS video straight out of a Sony HDR-CX550. I've converted it to AVI and MP4 (same thing as MTS?) but it's still there. Maybe that's not what you mean?

The camera was recording fine. Then this. I turned it off and restarted it and the video was fine again. Unfortunately not before I got about an hour with the lines.

[jagabo]

Are you saying the video has the same lines when played on the camera? If so, does the same video have the problem every time you play it?

[JonathanCMH]

Yes, it has those lines when played back in camera.

(I kicjed myself afterward because I had noticed the lines on the screen when recording and thought it might be a display issue. I didn't want to lose any footage from this cam angle--but by keeping going I lost it all instead of the time for a quick restart).

[cd090580]

It seems that the camera is defective. Time to do a repair

[JonathanCMH]

I was wondering the same. Though it did return to normal after a restart.

But is there any quick method to repair the video? I can see where the bands come from, so I was thinking of doing lots of overlays to produce a compositie image--but that seems labor intensive plus it might not align quite right.

My hope was/is that this is a common error and that some software piece can auto re-assemble / recompile the encoded video.

[jagabo]

I was wondering the same. Though it did return to normal after a restart.

You're not being clear here. Did the same video file play properly after restarting the camera. Or do you mean after restarting the camera new recordings didn't have the problem.

But is there any quick method to repair the video?

Are the bands in the same place in each frame? Or are they in different locations in each frame? If they are in the same place you might be able to repair the video. But you'll probably have to use AviSynth. A sample video would be helpful.

[JonathanCMH]

Hi Jagabo

Sorry for any mis-communication. The same video file did NOT play properly in camera after restarting the camera. The error remained in material that was already recordedwith the error. NEW material, after the restart, recorded clean without the error.

Thanks for your thoughts on this!

[JonathanCMH]

Oh, I tried uploading a segment a couple of times and it seems to finish uploading but I don't know if I've done it right because I don't see it.

[cd090580]

Hi Jagabo

Sorry for any mis-communication. The same video file did NOT play properly in camera after restarting the camera. The error remained in material that was already recordedwith the error. NEW material, after the restart, recorded clean without the error.

Thanks for your thoughts on this!

Check if there is not firmware update maybe it's a bug in the camera software...

[jagabo]

The same video file did NOT play properly in camera after restarting the camera. The error remained in material that was already recordedwith the error. NEW material, after the restart, recorded clean without the error.

That implies a problem with the camera. I suspect the camera is failing once it warms up. But cd090580's suggestion is worth a try.

I'll look at the sample video once it finishes downloading.

[jagabo]

A script like this cleans it up a lot:

function MoveColumn(clip c, int topos, int frompos)
{
    last = c
    col = Crop(frompos, 0, 5, -0)
    overlay(last, col, x=topos, y=2)
}

ffVideoSource("00022.mp4") 
ConvertToYV24()
MoveColumn(  80,  166)
MoveColumn( 166,  251)
MoveColumn( 251,  336)
MoveColumn( 336,  422)
MoveColumn( 422,  507)
MoveColumn( 507,  592)
MoveColumn( 592,  677)
MoveColumn( 677,  763)
MoveColumn( 763,  848)
MoveColumn( 848,  933)
MoveColumn( 933, 1019)
MoveColumn(1019, 1104)
MoveColumn(1104, 1190)
MoveColumn(1190, 1275)
MoveColumn(1275, 1360)
MoveColumn(1360, 1446)
MoveColumn(1446, 1531)
MoveColumn(1531, 1616)
MoveColumn(1616, 1701)
MoveColumn(1701, 1787)
MoveColumn(1787, 1872)

Unfortunately the columns aren't exactly 5 pixels wide so the edges aren't clean. You could probably interpolate at the edges to clean the remaining errors up a bit. I may have gotten the exact position wrong on a few of the columns. Oh, and there was no data to fill the far right column so I didn't address it.

[JonathanCMH]

Thank you so much, jagabo! That's much improved. I appreciate all the time you've given me.

And thanks to the others who offered their thoughts. I'll keep an eye on this cam and maybe try a firmware update.

[smrpix]

The reason jagabo's excellent script delivers not-quite-perfect results is because the camera encoded the video downstream of the error, so the edges are are aliased. There are also some color-aliasing artifacts. You'll never get this exactly right, unfortunately.

Do keep an eye on this going forward -- it's often much cheaper in time and reputation to replace an unreliable camera than to risk losing even a few hours' footage.

[JonathanCMH]

Thanks, smrpix. The clip I cut out quickly and submitted was converted to MP4 by Wondershare Videoconverter. I wonder if I'd have better results from the original MTS file out of camera

[jagabo]

Yes, the columns' edges are antialiased. 8x point resize:

[smrpix]

Thanks, smrpix. The clip I cut out quickly and submitted was converted to MP4 by Wondershare Videoconverter. I wonder if I'd have better results from the original MTS file out of camera

By all means if you have a short original clip post it.

[JonathanCMH]

Thanks! All the original files are fairly large (1.8-2.0 gigs) and I don't know if I have anything that will save a small clip as the original file type without altering it. I'll look about, though, and post a clip if I can.

[JonathanCMH]

After all your help earlier, I feel a bit shy about coming back to the well, but I'm having a terrible time figuring out what bits and pieces I need to make this script run.

What software pieces do I need?

I downloaded Avisynth, then figured I needed to download VirtualDub(?), but then I get codec errors... it seems like I need one more thing after another to make it all play well together. (I'm more familiar with your typical NLEs like iMovie, PowerDirector, Premiere Pro.)

Is there a dummies 1-2-3 step guide that you know of that puts it all together as a how-to? I'm not seeing it in guides.

[jagabo]

I used ffVideoSource() to open the video file. It can handle most common codecs and containers. It doesn't come with AviSynth so you have to download and install it:

https://code.google.com/p/ffmpegsource/downloads/detail?name=ffms-2.17.7z

Put ffms2.avsi and ffms2.dll in AviSynth's plugins folder so they load automatically every time AviSynth is started.

Create a text file with Notepad (or any other plain text editor) and paste the above script into it. Save the file in the same folder as the video you are working on (or save it anywhere but specify the full path to the file in the script). Change the extension from .txt to .avs.

You should now be able to open the script in VirtualDub (or any editor/encoder/player that supports AviSynth scripts) as if it was a video file (File -> Open Video File). There will be a pause when you fopen a video for the first time because ffms2 has to build an index file (same name as the source video but with ".index" as the extension). You won't notice with short videos but with long ones it can take a few minutes.

[JonathanCMH]

Thanks. When opening the .avs file, I get:

'Avisynth open failure: Script error there is no function named "ConvertTo YV24'

Did I need another piece? I have VirtualDub, AviSynth, the script file ending .avs?

[manono]

'Avisynth open failure: Script error there is no function named "ConvertTo YV24'

If you had a space before the 'YV24', remove it and try again:

http://avisynth.nl/index.php/ConvertToYV24

[poisondeathray]

YV24 requires avisynth 2.6.x branch. You probably have 2.5.8 installed

avisynth 2.6 RC3
http://sourceforge.net/projects/avisynth2/files/AviSynth_Alpha_Releases/AVS%202.6.0%20...9.exe/download



You might be able to improve the "slice" edges by using inpainting, such as avsinpaint or exinpaint in avisynth - it's of form of interpolating like jagabo suggested earlier. It's similar to photoshop's "content aware fill" or gimp's resynthesizer, where the algorithm tries to fill in pixels by looking at surrounding pixels. It works well on patterned backgrounds, but can lead to artifacts which flicker when used on video . Typically you'd need a temporal smoother applied through the same mask to smooth things over when used on video

[JonathanCMH]

There was no space before YV24--that was my bad copying. Thanks for the reply, manono.

poisondeathray's suggestion worked, thank you.

(This really is an amazing forum).

[jagabo]

Sorry, I forgot that YV24 requires AviSynth 2.6. Depending on what program gets the AviSynth output you might need to convert back to YV12 at the end -- ConvertToYV12().

[JonathanCMH]

No worries, jagabo. Thanks for all your help.

I'm now reading up on inpainting!