Deinterlacing-How does Magix do it?

AAProds wrote on 7/8/2024, 8:01 PM

Scenario: DV-AVI or Analogue AVI, interlaced.

Options: on the video properties menu, there are now only 3 options: Full frame (no interlacing), BFF of TFF, as well as the "Processing/Interpolate" tickbox.

Question: what does it all mean?

What's the purpose of the droplist? Should that be set on what the source file is or is it used to change the output? eg if I have an interlaced DV-AVI, do I choose Full frame ie for a progressive output, or BFF which is what the source file is? From test I've done, that droplist makes no difference to the output.

What is the purpose of the "Processing" tickbox? Does that force a blend between each field to create a frame?

And what does Magix actually do when it deinterlaces: blend, discard? It obviously doesn't double-rate deinterlace.

I'd love your thoughts on the whole concept of deinterlacing in Magix.

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CubeAce wrote on 7/21/2024, 9:17 AM

@Can-Dive

Hi.

I'm using version 1 but I think improvements may be minimal in Vs 2 going by the examples given on their website here. Look at the slow-mo of the family on the beach. Pay particular attention to the arms of each person and the gaps between. It is not a particularly high res file example either. As far as I can see the real differences would be in the processing time as it now uses hardware acceleration if you have an nvidia card whereas my version seems to really rely on the processor. Also now 3D and different bit depth support but there is a free trial you could try out for yourself. Results will also vary depending on the video format and frame speed that you start off with. Whether your video recorder can negate the effects of rolling shutter or not. Not all video cameras do. Also the speed of the action itself. Like I said earlier, sometimes it will work much better than other times but on average I find using slow-mo at the time of shooting much better than done as a post process. As a method of then trying to speed the clip up for export to reduce judder it just makes different optical problems that are noticeable if it is not a clean render.

I'm not against using the product as every person may experience different results to myself depending on the conditions I mention above. I have similar problems using Hide. To get rid of a dust bunny as long as the shot does not zoom it is great but for everything else it is often a lot of work and not always a 100% successful at making an invisible patch.

Ray.

Can-Dive wrote on 7/27/2024, 8:22 AM

Question: what does it all mean?

What's the purpose of the droplist? Should that be set on what the source file is or is it used to change the output? eg if I have an interlaced DV-AVI, do I choose Full frame ie for a progressive output, or BFF which is what the source file is? From test I've done, that droplist makes no difference to the output.

What is the purpose of the "Processing" tickbox? Does that force a blend between each field to create a frame?

And what does Magix actually do when it deinterlaces: blend, discard? It obviously doesn't double-rate deinterlace.

I'd love your thoughts on the whole concept of deinterlacing in Magix.

@AAProds @johnebaker @CubeAce

Al and John EB thanks for answering my queries regarding interpolation. Ray, thanks for your detailed comments regarding ProDad Respeedr. I have Respeedr V1 so I may take your suggestion and trial V2.

As for Al's original question; what does the droplist mean? I think these options affect how the interlaced video play on the program monitor. I don't believe it is used to change the output since this option is available when the export codec is selected. As to how Magix deinterlaces video to produce a progressive file is a mystery but then again other commercial editors don't delve into this much detail either although Vegas seems to be more transparent than others in their methodology.

Unfortunately I'm not sure what the Processing - interpolate intermediate images tick box does since I didn't notice any material difference in playback when switched on or off in my testing. I initially suspected it had something to do with smoothing monitor playback when the project frame rate is different to the source video frame rate although I would have thought this would be automatically applied and not require a tick box. In search for an answer I came across the following in the user manual;

These three menu features appear when you right click on an object in the project window which is how you get to the droplist Al mentions. Anti-interlace filter and Border cropping adjustment become "available" if you right click an image. For video they are grayed out. Interpolation for interlace footage does not appear for images and the closest feature to it is the Processing - interpolate intermediate images tick box which is only available for video. Reading the description, the only "interlace artifacts" that I am aware of is the combing effect John EB mentioned. But the tick box doesn't seem to clean up the combing effect so I'm still unsure what it actually does.

Al, I'm not sure if the above observations have shed any light on your question but I thought I would share them with you regardless. Cheers!

AAProds wrote on 7/27/2024, 9:45 AM

@Can-Dive

Thanks very much for that. As you have found, Interpolate Intermediate Images doesn't seem to do anything when the object frame rate is at or higher than the Movie framerate. However AndyW @me_again has pointed out that it comes into play if you slow the clip down. You can use it to inert intermediate images. When you tick one of the boxes, the other (either in Video Object Properties or the Speed control box) other will become ticked too.

Based on lessons from the discussion so far, I've drafted a currently "unlisted" web page for the subject here.

As for that text from the manual, the whole area is a dog's breakfast and written in double-dutch, as we antipodeans call it. The whole manual and Help needs a complete overhaul, but where do you start? 😂

Can-Dive wrote on 7/29/2024, 12:43 AM

@AAProds

Hi Al, thanks for the link. Now, I now understand why you are interested in determining how deinterlacing works in MMS. I found your comment interesting that Interpolate Intermediate Images tick box is in the Speed effect and in the Object properties. I initially wondered why the same function would be located in two different places and then I realised that the Object properties tick box must be related to "Object stretch mouse mode" where you can stretch a clip to slow it down. Now it all makes sense!

But now I'm wondering what Interpolation for interlace footage is since it does not appear in the context menu? Maybe it was an old function that is now deprecated but wasn't removed from the manual. I'll do a search on the forum to see if it is mentioned and if I don't find an answer I'll post a new thread.

johnebaker wrote on 7/29/2024, 2:23 AM

@Can-Dive

The Anti interlace filter right click option is still available for still images.

For video, AFAICS it is applied automatically for previewing in program, the option is available in the export as video dialogs.

OT: when copying an image from the forum to post in another topic please view it full size by clicking on the preview image in the post.

John EB

Can-Dive wrote on 7/29/2024, 6:19 AM

@johnebaker @CubeAce

Hi John EB,

So if I understand correctly, this feature, which was available in previous versions, (see screenshot below) was automated for preview/playback and therefore deleted from the context menu. This is an enhancement rather than the feature being mistakenly left out of the context menu. Therefore, the Help and User Manual have not been updated to reflect this change/enhancement. Is this correct?

Do you know what version this enhancement was made? Also, your screenshot of the export dialog - Apply anti-interlace filter. Was this tick box available in previous versions of the export menu or did they move this feature from the context menu to the export menu?

Hi Ray,

I copied your comments from the post that was closed;

The first option if I am reading it correct would only apply to video footage so that if a still was taken from it you would not get a mismatch of top field vs bottom field. For video that option appears when choosing 'Properties' from the drop-down list when you right click. The option is not available for stills as they do not have top and bottom fields.

Ray, I could not find this specific feature under Properties. Are you referring to Interpolate Intermediate Images?

CubeAce wrote on 7/29/2024, 11:10 AM

@Can-Dive

Apologies. I could not clearly see the last image you posted when I replied. How old is the program that image where it shows came from? I have never personally seen that but only used the programs since the 2018 version, nor have I seen that image in any manual although its presence is mentioned.

I was mistakenly thinking you were after the Interpolate Intermediate Images.

There have been features taken away or altered / missing presumed unwanted considering the lack of response from Magix over certain bug reports as well as added features over the years as the technology has progressed / altered. I think @johnebaker has had the nearest answer.

Ray.

johnebaker wrote on 7/29/2024, 11:14 AM

@Can-Dive

. . . . automated for preview/playback and therefore deleted from the context menu . . . .

Based on my observations when interlaced video is imported, the resulting playback suggests that it has been de-interlaced and filtered, therefore the option would no longer be needed.

Do bear in mind that the older versions of MEP/MMS/VPX were using a different 'engine' to the current Infusion engine.

MMS 2020 which uses the Infusion (1) engine, has the 3 Interlace options on right click of video object

MMS 2022 uses the Infusion 2 engine and has the single option available on right click of video object

It is not beyond the realms of possibility that 2 options were dropped with the introduction of the Infusion 2 engine in MMS 2021 - I do not have a VM with this version installed, so cannot check.

. . . . the Help and User Manual have not been updated to reflect this change/enhancement. . . . .

To quote from Al's comment here :-

. . . . 'the whole area is a dog's breakfast and written in double-dutch, as we antipodeans call it. The whole manual and Help needs a complete overhaul, .. . . . ?'

@CubeAce commented:

. . . . The option is not available for stills as they do not have top and bottom fields . . . .

That is correct for the Object Properties dialog. However as I said previously there is an Anti interlace filter right click option is still available for still images. Many image encoding formats are rasterized, this may lead to issues, eg Moiré effects, which an Anti interlace filter may be able to fix/reduce.

John EB