@AAProds From the Vegas help

I've read these but it's way too early in the day for me, good luck

Wikipedia Progressive scan/noninterlaced scanning

Wikipedia Interlaced video

Wikipedia Deinterlacing

Wikipedia Field (video) interpolate

@AAProds @me_again @Gid

Hi Al.

I would say my experience with interlaced video is almost non existent except for once instance.

When Flickr first allowed video to be uploaded my files which were all progressive suffered badly from jaggies when playing back anything with panning as Andy described, so I got in touch with the Flickr development team and it turned out their uploader was reprocessing video to interlaced output if the file was of a European standard (25 or 50 fps). It was very noticeable and took them a month to sort out but sort it out they did.

So my conclusion is if the header file is read correctly and the export settings set correctly you should not see any tearing during panning (and sometimes even when the camera is still but there is noticeable movement within the frame) if it needs to be exported as interlaced at at all. My suggestion would be to deliberately set the output to the opposite of the file type to see it Magix compensates. I think that should prove whether the header is being read correctly and that the program can successfully re-encode the file without problems.

As for interpolation. I have had issues in the past where using it has made the result worse. My guess is that if using files close to or above 48fps it should not be used. I was always under the impression that an interpolated frame would just be a blend of the prior and post frames which at lower frame rates would produce an image similar to a frame with a slow exposure time would produce making it appear smoother. Another time it can be useful is when making a normal speed video go into slow motion and in plugins like ProDad ReSpeeder you get a choice of how those images are blended.

Ray.

My 1080 PAL AVCHD camera shoots interlaced as did my previous SD tape camera so I've years of experience with it.

@CubeAce Interpolation is the creation of two separate frames from the two fields of an interlaced frame by estimating what should be there in the missing fields. Obviously the quality of this will depend upon the accuracy that is achieved by software/hardware.

Blending is when the two fields are blended into one frame. Whilst this may be satisfactory with fairly static subjects if there is movement it gives ghosting. Ghosting is different to the combing effect obtained if you do not deinterlace. The ghosting is similar to what you get when you slow down shots on your timeline and have the additional frames produced with resampling which is like a crossframe.

It is often said that hardware, such as your TV's player, does a better job of deinterlacing in real time than most software taking its time. I export AVCHD/Blu-ray for my TV. For most steaming services you need to give them progressive. Until recently I used Handbrake with Decomb and BOB settings to convert my 50i to 50p. The results were acceptable but nowadays having Vegas Pro I use its Smart adaptive Deinterlacing to convert my 50i files. It does a great job. Jagged edges to road markings, sloping roofs etc are now a thing of the past. I don't know if MS and VPX have this.

Thanks all.

Andy, I will do that test.

Gid, That second screenshot from Vegas is what "I think" we should have (or similar).

Master @jagabo from Videohelp has made this interlaced file for me. It shows how Magix processes interlaced files with variations to the movie frame rate and interlace settings (TFF or BFF) in the video object properties.

https://drive.google.com/file/d/1De7kb_aY1kjowVi-cQ1CTvnAuZEakA8I/view?usp=sharing

@AAProds

Hi Al

. . . . It shows how Magix processes interlaced files with variations to the movie frame rate and interlace settings (TFF or BFF) in the video object properties . . . .

Can you clarify how it does this please.

John EB

@johnebaker

John still gathering my thoughts but so far:

When importing analogue AVI, the video object properties should match the field order of the file. If the file is TFF and you choose BFF, with the movie setting T 50FPS, the frame dance forward/backward will occur resulting in slight jerkiness.

If the frame rate of the movie is set to double the video's framerate, Magix will do a pretty good job at double-rate deinterlacing, where is field is turned into a frame. I compared it with QTGMC and Magix isn't as good.

"Interpolate intermediate images" doesn't seem to have an effect in any scenario.

Magix deinterlacing performance:

Field processing:

Movie setting 25fps, file 25fps TFF, Video properties set to TFF. OK, every second field.

Movie setting 50fps, file 25fps TFF, Video properties set to TFF. Good, every field is frame at double frame rate=smoother:

Movie setting 25fps, file 25fps TFF, Video properties set to BFF. OK, every second field:

Movie setting 50fps, file 25fps TFF, Video properties set to BFF. Bad, fields jumping back and forth.

Conclusion: if after best quality, deinterlace outside Magix and import your video as a deinterlaced, double frame rate file..

If happy with Magix, set the movie settings to 50fps, which will give noticeably smoother movement in your video.

Note, none of this is relevant to Progressive video ie from most modern video devices. Doubling the frame rate will merely force Magix to insert a frame to match the previous frame. Motion will not be smoothed out unless the frame rate of the video itself is increased eg with re-speeder or filters such as AVISynth's FrameRateConverter or RIFE.

Hi Al

Thanks for the clarification.

I also did some testing changing framerate and exporting progressive with and without Interpolation.

Without interpolation it looks like duplication of each frame, and with interpolation on, frame/field blending.

John EB

@johnebaker

Hi John.

That was my conclusion earlier when I saw results of trying for myself with progressive footage. It's very evident if videoing fast action and then using the scroll wheel on the rendered video once re-imported.

As for using ProDad Respeeder for smoothing out footage. Depending on the footage I have found results to be very variable as it often seems to produce its own artifacts that become more distracting than the original problem.

Ray.

@johnebaker

John, interesting. Could you drop me a 59.94i file to have a play with?

@CubeAce

Ray, that Respeeder is awful. I'll steer well clear of that.

@AAProds

Hi Al.

It works reasonably well with anything shot at a distance but even then if there is any camera movement the sides of the frame gets weird distortions if the foreground is busy, like bushes, plants, anything with fine detail. The less frames it has to predict, the better the outcome on average. Like I said, the outcome is not predictable. Sometimes it does a good job and other times not so much. I actually prefer to use the respeeder supplied within Magix.

Ray.

@AAProds

Hi Al

. . . . a 59.94i file . . . .

To confirm you would like - a NTSC 29.97 fps interlaced (59.94i) file.

John EB

@AAProds

"Interpolate intermediate images" doesn't seem to have an effect in any scenario

Not for the de-interlacing but it does when you slow the clip down. Have the movie settings at 50 fps and reduce the speed to 50% or less (retaining the original Interlace structure) then click through it with the right curser arrow (or whatever it's called)

I use "Interpolate intermediate images" occasionally. It's a good rough and ready tool for family Whatsapp throwaway clips etc.

AndyW

@johnebaker

John, arr, no, I thought you had a 59.94i file. 29.97i translates to 59.94P. 59.94i would double rate to 119.88P.

Your videos are showing each field as a frame, so they are 59.94P (double-rate deinterlaced from 29.97i).

I can't get the interpolate effect to work on a double rate file like you have.

@me_again

Andy, thanks, just tried that and yes, I can see it on a slowed clip. Interestingly, when you tick the "Interpolate" on the speed controller, the box is also ticked on the Video Properties.

@AAProds

Hi Al

. . . . I thought you had a 59.94i file . . . .

I do, that is a standard NTSC 29.97 fps interlaced video file, by convention the 'i' refers to fields, whereas the 'p' in progressive refers to frames.

John EB

@AAProds @CubeAce

Al, am I understanding this correctly that with your first example; Movie setting 25fps, file 25fps TFF, Video properties set to TFF, the player jumps to every second frame because its displaying each Top field and with your second example of Movie setting 50fps, file 25fps TFF, Video properties set to TFF, the player displays every frame; the top field, then the bottom field, then the next top field etc?

Ray, were you using Prodad Respeedr V1 or the just released Prodad Respeedr V2?

@Can-Dive

Candrive, yes, that's right. At the original frame rate, it looks like Magix keeps whatever field you have set in the Video Properties and "discard"s the other. There's no blending. It doesn't seem to matter which one is kept. Only when you set the frame rate to double will you get both fields, and they must be in the correct order in Video Props eg TFF for a TFF file.

However, I've since found that, for the original frame rate, if you set the Video Props to Full Frame (Non Interlaced), you'll get two fields blended together: 4+5 followed by 6+7 and so on.

For the doubled frame rate, a duplicate frame is inserted eg 1+2 followed by 1+2 followed by 3+4 followed by 3+4.

@AAProds

Hi

Setting to Full Frame does indeed blend to 2 fields as you can see in the screenshot below

The movement of the car and flag shows the combing clearly due to the time (temporal) differential between the 2 frames.

. . . . it looks like Magix keeps whatever field you have set in the Video Properties and "discard"s the other. . . .

This begs the question - how are the missing field lines replaced?

What i think is happening is the 2 fields are de-interlaced and, where movement is present, interpolated, the interpolation occurring between the field set in the video and the following field, correcting for the temporal (time) difference between the fields.

John EB

@AAProds @johnebaker

Al, for my own edification, if we take your first example; Movie setting 25fps, file 25fps TFF, Video properties set to TFF; I note that the fields that appear are 26, 28, 30 etc. If we change the settings to; Movie setting 25fps, file 25fps BFF, Video properties set to BFF; will the sequence of numbers be 27, 29, 31 etc?

John EB, by setting Full frame, isn't the "blend" just simply adding the the top field + bottom field to create one full frame? What field lines would be missing unless you mean how are the missing fields lines replaced after the video is deinterlaced? In that case, I guess that is where all the different blending algorithms and methods come into play.

@Can-Dive

Al, for my own edification, if we take your first example; Movie setting 25fps, file 25fps TFF, Video properties set to TFF; I note that the fields that appear are 26, 28, 30 etc. If we change the settings to; Movie setting 25fps, file 25fps BFF, Video properties set to BFF; will the sequence of numbers be 27, 29, 31 etc?

Candive, yes, that's correct.