Horizontal Lines Script or Software?

[NLP]

Hi guys, I have been using Avisynth for over 15 years.

But until today I could not create a script that works well with black horizontal lines because they are of different sizes.

Almost all the VHS tapes I have are very oxidized because where I live the normal humidity is almost 90% and it is also very hot.

In this case, do you know any program or Avisynth script that can find these horizontal lines automatically in the video so that I can do a faster and more optimized manual editing?


Thank you very much in advance

[jagabo]

Try searching the forums for "comets". Is that what you're seeing?

[NLP]

Try searching the forums for "comets". Is that what you're seeing?

Thanks Jagabo, I did a search in the forum about "Comets"

But I found no solution, in my case I have some 6 hours (on average) vhs tapes oxidized. And the main problem is the black horizontal lines of various sizes.

It also has thin transparent horizontal lines and white lines of various sizes.

In this case, if there was a way for me to scan where these errors are throughout the video, with the exact time, then I could do a much faster and more accurate manual editing. Instead of segmenting the video into each type of error and creating a script for each case.

Do you know if there is any script or program that does this?

Thanks a lot!

[jagabo]

You'll need to upload a sample of the source with the various lines. Don't filter or re-compress as that will change the nature of the lines.

[NLP]

You'll need to upload a sample of the source with the various lines. Don't filter or re-compress as that will change the nature of the lines.

Video Sample:


https://drive.google.com/file/d/1YI1Dv6Q7bJhA5a2Y59Y9S80qsyEuT02b/view?usp=sharing


Thank you in advance!

[johns0]

You can upload up to 500mB here,lot easier to get to than google drive.

[lollo]

You'll need to upload a sample of the source with the various lines. Don't filter or re-compress as that will change the nature of the lines.

Video Sample:


https://drive.google.com/file/d/1YI1Dv6Q7bJhA5a2Y59Y9S80qsyEuT02b/view?usp=sharing


Thank you in advance!

As jagabo said, "Don't filter or re-compress as that will change the nature of the lines." If you capture in h264 is not good for further restoration, and in general.

BTW, we already answered you on doom9's forum that writing an AviSynth script able to detect and report the corrupted frames will be very difficult/impossible, given the nature of the defect. But maybe some other users has some excellent idea...

[jagabo]

Would a list of frame numbers like this help?

9
14
15
16
17
18
19
20
21
24
109
111
160
161
164
169
170
171
172
173
174
175
179
181
182
183
184
185
186
188
189
190
193
194
195
223
226
232
243
267
269
270
271
272
273
274
275
276
277
278
279
281
283
322
323
347
348
349
350
351
352
353
354
355
356
357
358
379
477
582
665
697
757
807
808
809
810
811
812
828
832
833
834
835
836
837
840
841
842
843
844
845
846
847
848
849
850
851
852

[NLP]

As jagabo said, "Don't filter or re-compress as that will change the nature of the lines." If you capture in h264 is not good for further restoration, and in general.

BTW, we already answered you on doom9's forum that writing an AviSynth script able to detect and report the corrupted frames will be very difficult/impossible, given the nature of the defect. But maybe some other users has some excellent idea...

lollo thanks for your help!

My sample has no compression. This VHS tape has many physical scratch defects on it.

So I did the capture with a JVC-VT7800 and also using PAN-EZ27 (I mean CNR) via HDMI 60 frames. And in my humble opinion, it can cut off several horizontal lines in the process. And even using Didee's script it couldn't help much.

How I miss the old days when I used Didee + Pirej's script on a bad VHS tape. It has fixed many video errors like in this post: https://forum.videohelp.com/threads/339206-old-vhs-restoration#post2108662

And also in this other post an example of the effectiveness of this script: https://forum.videohelp.com/threads/308840-old-VHS-restoration/page2#post2077635

Would a list of frame numbers like this help?

9
14
15
16
17
18
19
20
21
24
109
111
160
161
164
169
170
171
172
173
174
175
179
181
182
183
184
185
186
188
189
190
193
194
195
223
226
232
243
267
269
270
271
272
273
274
275
276
277
278
279
281
283
322
323
347
348
349
350
351
352
353
354
355
356
357
358
379
477
582
665
697
757
807
808
809
810
811
812
828
832
833
834
835
836
837
840
841
842
843
844
845
846
847
848
849
850
851
852

Hello jagabo,

Sorry, I didn't understand.

Are these by any chance the frames that contain the horizontal lines I mentioned at the beginning of this thread?

And how did you get those numbers?

Thanks for your help!

[jagabo]

My sample has no compression.

Your sample has a ton of compression with a lossy codec. It's also been deinterlaced. Both of those things make issues like this much harder to detect. If you had captured as interlaced video with a lossless codec it might much easier to detect and fix the problem.

Would a list of frame numbers like this help?
9
14
15
16
17
...

Are these by any chance the frames that contain the horizontal lines I mentioned at the beginning of this thread?

Yes.

And how did you get those numbers?

An AviSynth script. But it's not perfect. There are some false positives and some false negatives. And the script relies on certain properties of the particular video. Properties which other videos may not have.

function AbsSubtractY(clip v1, clip v2)
{
    mt_lutxy(v1, v2,"x y - abs", chroma="-128")
}

LWLibavVideoSource("L06-31 3capt V7800EZ27 60q TBC.mp4") 

Crop(0,8,0,-32) # avoid noise at the top and bottom of the frame
src = last


# build a sample image for comparison
SelectEvery(8).Trim(2,33) # get 32 "clean" frames
Merge(SelectEven(), SelectOdd()) # merge them all into one reference image
Merge(SelectEven(), SelectOdd())
Merge(SelectEven(), SelectOdd())
Merge(SelectEven(), SelectOdd())
Merge(SelectEven(), SelectOdd())
medge = Crop(706,0,4,-0) # get just the border near the light to dark transition near the right edge of the video

src
Crop(706,0,4,-0)

AbsSubtractY(last, medge).mt_binarize(32).BilinearResize(64,height) # subtract each frame from the reference frame, absolute value
WriteFileIf("list.txt", "AverageLuma>0.5", "current_frame", flush=true)

StackHorizontal(src, last) # for a visual reference

Basically, the script looks for the black border intruding into the light band near the right of the frame when time base errors shift the lines to the left.