Interlaced Video

general questions about Neat Video
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Avagadro1
Posts: 3
Joined: Sat Apr 03, 2021 8:21 pm

Interlaced Video

Post by Avagadro1 »

This is a pre-purchase question.

I am capturing old family VHS tape video (using either VirtualDub or AmerecTV), in AVI format, standard definition, 720x480, INTERLACED, editing in Adobe Premier Elements v. 11, then to be burned to DVD (thus the importance of keeping the video interlaced, which the DVD/Television will itself de-interlace).

Due to lots of noise in these tape captures, I am testing the demo version of Neat Video v. 5. Neat Video is working properly as a plug-in to my Adobe Premier Elements, and I observe that Neat Video has real potential.

Because I am working with interlaced video, of course I can see the combing effect in the video when viewing in the Premier Elements Monitor Panel (or if viewing in any computer media player).

As soon as I APPLY the Neat Video denoiser profile to my video project in Premier Elements, the combing effect as viewed in the Monitor Panel disappears, as though the video was being de-interlaced.

Question: Is my video being de-interlaced when I apply the Neat Video denoiser profile, or is this just some kind of visual anomaly as viewed in the Premier Elements Monitor Panel but the actual video remains interlaced?

Thank you for any help.
emmrecs
Posts: 21
Joined: Sat Jan 16, 2010 5:01 pm

Re: Interlaced Video

Post by emmrecs »

I'm not sure whether this also applies to the Trial version, but in the full version 5, on opening the NV workscreen (as a plugin from, in my case, Magix' Video Pro X) I immediately see a message which asks me to specify whether the footage is Progressive or Interlaced. Do you not see that message? If not, perhaps NV is somehow "working this out itself" or it is not an option in the Trial version.

HTH
Avagadro1
Posts: 3
Joined: Sat Apr 03, 2021 8:21 pm

Re: Interlaced Video

Post by Avagadro1 »

emmrecs wrote: Sun Apr 04, 2021 12:42 pm I'm not sure whether this also applies to the Trial version, but in the full version 5, on opening the NV workscreen (as a plugin from, in my case, Magix' Video Pro X) I immediately see a message which asks me to specify whether the footage is Progressive or Interlaced. Do you not see that message? If not, perhaps NV is somehow "working this out itself" or it is not an option in the Trial version.
To emmrecs:

Thank you for your response. When I open the NeatVideo workscreen I DO NOT get a dialog or any form of question asking whether my video is interlaced, de-interlaced or progressive. However, I assume that the NeatVideo program "knows" it's interlaced because the image in the NeatVideo workscreen is vertically squished by about half (yes, it looks weird). As someone who's never before used NeatVideo, I assumed that's the way NeatVideo works with interlaced, i.e., in NeatVideo my 720x480 appears as a highly distorted 720x240 so that NeatVideo can "operate" on the true image lines. I do not know for sure that this is what's going on, but it seems a reasonable guess. However, I'm near certain that the actual video file (in Premier Elements) is retained at the full 720x480.

As described in my original post, in the Premier Elements Monitor Panel, BEFORE applying the NeatVideo effects, I can see the image combing characteristic of interlaced video. After I APPLY the NeatVideo denoising effect, the interlaced combing as viewed in the Premier Elements Monitor Panel disappears --- thus my confusion as to what's going on.

Separate, but related, from reading the NeatVideo website, I thought that the DEMO version of the program was exactly the same as the licensed version, except limited to resolution and length, and the insertion of the "Neat Video" overlay in the (test) project. If I could see the message dialog that you described (asking whether the video was Interlaced or Progressive), it would be quite helpful. I nonetheless would wonder whether application of the NeatVideo denoiser in Premier Elements also de-interlaces, which in my projects (VHS > edit > DVD) wound not be desirable.

Hopefully we can get some further help here. Thanks again.
NVTeam
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Joined: Thu Sep 01, 2005 4:12 pm
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Re: Interlaced Video

Post by NVTeam »

Avagadro1:

Plug-ins for Magix and for Premiere are different in their behavior because Premiere informs the plug-in about the scan type (progressive vs interlaced), while Magix does not and so the plug-in for Magix has to ask the user. It is normal that the plug-in for Premiere does not ask that, since it already knows that from Premiere itself.

An interlaced video stream is a series of fields that are twice less tall than the full frame, so you see a 720x240 field, which is the normal size of a field in such a video stream. Please see this post for more on that.

When working with interlaced video stream, Neat Video does not change the scan type. It receives individual fields and it returns the same set of
individual fields back to Premiere. It does not deinterlace the video stream.

If something changes in Premiere's Monitor after applying Neat Video, then perhaps Premiere simply uses a different display method for rendered data. Perhaps it applies deinterlacing for display purposes in this case. In any cases, it is something happening on the side of Premiere. Try to change the preview mode to see individual fields, if your version of PRE allows that.

Vlad
Avagadro1
Posts: 3
Joined: Sat Apr 03, 2021 8:21 pm

Re: Interlaced Video

Post by Avagadro1 »

Mr. Vlad:

Thank you for the clarification. Got it.

Suggestion: Although the numbers have probably become fewer and fewer, it seems that there are still a few of us who are converting old family VHS tapes to digital, editing, then creating DVDs. Those who have done their homework will want to keep the VHS video as interlaced from capture to DVD.

In light of the above, and from the NeatVideo Forum archives where quite a few NeatVideo users/testers have been confused or otherwise inquired about the appearance and workings of interlaced video in NeatVideo, this may be worth a new, additional, specific section of the NeatVideo User Guide and tutorials.

Thanks again for your help.
NVTeam
Posts: 2545
Joined: Thu Sep 01, 2005 4:12 pm
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Re: Interlaced Video

Post by NVTeam »

Thank you for the suggestion. We will think about that.

Vlad
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