Whist both files declare themselves as interlaced they are actually 25 fps progressive.

I don't agree. Yes, the "Deinterlaced" 00059 file is deinterlaced; as Eric says, 25 fps Progressive. You can see this if you create a 50fps movie in Magix, add the Deint file and then step through; you'll see the frame duplication. No changes occur if change the Video object properties from Full Frame, Interlaced BFF or Int TFF. If you tick Intermediate Images, you'll get motion every frame (ie at 50fps) but Magix merely blends the two frame together=smoother motion but blurry at the edges in motion.

In effect, the movement is being spread over 25 progressive frames per second.

On the other hand, the "normal" 00060 file is definitely interlaced. If you put it onto a 50fps timeline and step through, you'll see motion on every frame, because Magix is creating a frame out of each field ie 50 fields into 50 frames. In this case it's Top field first; if you put the object properties to BFF, you'll get the forward-backward motion caused by the fields being read in the wrong order.

Further evidence is provided if you open it in a program which doesn't deinterlace eg Virtual Dub or VLC Player (with deinterlacing turned off), you'll see the jaggies. Jaggies=interlacing.

In my view, @jak.willis observation of the relative smoothness is supported by the evidence: the 25 frames per second progressive file ("deint") should be jerkier than the 50 fields per second interlaced file (the reason 25fps tape captures look so much smoother at 50fps).

What to do about the smoothness of the deinterlaced files? Unless you use frame interpolation to create a 50 frames per second file (a high-level process), you could try, as I suggested earlier, to export it as an MPEG 2 file. You'd then you'd get 50 fields per second and theoretically smoother video. Whether this would actually work from a Progressive base file I'm not sure.

Edit: just tried an MPEG 2 export; no go. All Magix appears to do duplicate each frame so you end up with 25 pairs of duplicated fields.

Here's a MP4 snippet render of a conversion to 50 frames per second of the Deint file (00059) using the RIFE plugin of AVISynth. It's not perfect (see the bouncy titles at the start) but does a pretty decent job.

https://drive.google.com/file/d/1iE00wUDCDkxDp8j4BqIHufGhZ4jw-yNh/view?usp=sharing

On the other hand, the "normal" 00060 file is definitely interlaced

@AAProds Yes you are correct (partly). I only checked on the intro with the fly out over the river and city and that is definitely 25fps as I get 25 duplicated frames per second. But after the intro when the programme proper starts it changes to 50 different frames per second!

I agree about the 50 fps versus 25 fps smoothness. I don't like 25 fps. Movement across the screen can look very jerky. Unfortunately Jak is probably stuck with it unless he can find some reasonably priced software that will create frame interpolation as you mention.

Here's a MP4 snippet render of a conversion to 50 frames per second of the Deint file (00059) using the RIFE plugin of AVISynth. It's not perfect (see the bouncy titles at the start) but does a pretty decent job.

https://drive.google.com/file/d/1iE00wUDCDkxDp8j4BqIHufGhZ4jw-yNh/view?usp=sharing

 

Actually I find it more than a pretty decent job. It's very good considering the low resolution and probably solves Jak's problem.

I wonder what AVISynth is like for deinterlacing 50i into 50p? I'll try it sometime. Thanks for mentioning it.

@ericlnz

Hi

I agree with Al that the 00059 file appears to be deinterlaced to progressive and by the looks of it it has been Motion Compensated, as shown by the jaggies and artefacts in the higher motion areas, these are caused by higher compression to keep the transmitted 'progressive' video within the channel bandwidth,.

MediaInfo and Vegas showing it to be intelaced could be a result of the recording being put into a .mts container file which is normally used for AVCHD/h.264 interlaced and by default the recorder marks it as so.

00060 is interlaced however jaggies do not infer interlacing, combing does and it is present in some areas of very fast motion eg:

John EB

Here's a MP4 snippet render of a conversion to 50 frames per second of the Deint file (00059) using the RIFE plugin of AVISynth. It's not perfect (see the bouncy titles at the start) but does a pretty decent job.

https://drive.google.com/file/d/1iE00wUDCDkxDp8j4BqIHufGhZ4jw-yNh/view?usp=sharing

 

Here's a MP4 snippet render of a conversion to 50 frames per second of the Deint file (00059) using the RIFE plugin of AVISynth. It's not perfect (see the bouncy titles at the start) but does a pretty decent job.

https://drive.google.com/file/d/1iE00wUDCDkxDp8j4BqIHufGhZ4jw-yNh/view?usp=sharing

 

I’ve just looked at that render you did on my phone, and it looks a hell of a lot better to me. I will also take a look at it on my TV later today.

So would the problem appear to be more to do with the frame rate causing the issue then? Or is it definitely all because of the deinterlacing?

@jak.willis

So would the problem appear to be more to do with the frame rate causing the issue then? Or is it definitely all because of the deinterlacing?

Jak, they are related.

My understanding is this: the interlaced file has an "effective" frame rate of 50 "frames" per second because your eyes are seeing 50 fields per second. If the file is deinterlaced to 25 frames per second, depending on the method used, the fields are merged so you only end up with 25 frames per second. I suspect that that is causing the jerkiness. Because of the PAL TV standard, which requires Interlaced video, they have added the extra "frames" to make up the 50 fields required, hence the double frames 112233445566.

So, IMO the deinterlacing has created the jerkiness.

@jak.willis

So would the problem appear to be more to do with the frame rate causing the issue then? Or is it definitely all because of the deinterlacing?

Jak, they are related.

My understanding is this: the interlaced file has an "effective" frame rate of 50 "frames" per second because your eyes are seeing 50 fields per second. If the file is deinterlaced to 25 frames per second, depending on the method used, the fields are merged so you only end up with 25 frames per second. I suspect that that is causing the jerkiness. Because of the PAL TV standard, which requires Interlaced video, they have added the extra "frames" to make up the 50 fields required, hence the double frames .

So, IMO the deinterlacing has created the jerkiness.

It’s always a mystery to me as to why UKTV were doing this in the first place. Because myself and others complained direct to them countless times, but every time they came back saying they cannot find a fault. So it’s taken 3 years for them to finally accept that there was a problem somewhere, and to fix it! Quite astonishing considering they’re meant to be a so-called ‘major broadcaster’

Anyone working there with the slightest clue of what they’re doing would surely notice and fix such a stupid mistake? How can it take 3 years??

@jak.willis

This unfortunately isn't going to help with your current problem however ...

As you are no doubt aware, U&Drama is transmitted on SDN multiplex and U&Drama+1 is transmitted on ArqA. In my experience ALL channels transmitted on an ArqA multiplex have a "soft" picture at best and blocky, noisy pictures at worst; ArqB is even worse.

I suppose that the TV companies pass the programs over to the Multiplexer who then transmits them. If that's the case I wonder how much control the TV companies have over the quality that out TVs receive, especially as I believe that the BBC own the majority shares of UKTV.

I've noticed with the clips that you've shared that they are recorded on U&Drama+1. Is there a reason for that?

This afternoon I recorded a Clssic Eastenders on my little kitchen TV that records direct from the aerial i.e. no processing as such.

The Mediainfo (note U&Drama on the left ∴ U&Drama on the right obviously 😇:-

There are one or points in there that I find interesting that lead me to believe even more what I think of the ArqA multiplex.

AndyW

@jak.willis

This unfortunately isn't going to help with your current problem however ...

As you are no doubt aware, U&Drama is transmitted on SDN multiplex and U&Drama+1 is transmitted on ArqA. In my experience ALL channels transmitted on an ArqA multiplex have a "soft" picture at best and blocky, noisy pictures at worst; ArqB is even worse.

I suppose that the TV companies pass the programs over to the Multiplexer who then transmits them. If that's the case I wonder how much control the TV companies have over the quality that out TVs receive, especially as I believe that the BBC own the majority shares of UKTV.

I've noticed with the clips that you've shared that they are recorded on U&Drama+1. Is there a reason for that?

This afternoon I recorded a Clssic Eastenders on my little kitchen TV that records direct from the aerial i.e. no processing as such.

The Mediainfo (note U&Drama on the left ∴ U&Drama on the right obviously 😇:-

There are one or points in there that I find interesting that lead me to believe even more what I think of the ArqA multiplex.

AndyW

Hi Andy,

Yeah, the ones going out now are interlaced as they should be. But previously, for 3 years, they were going out de-interlaced, which screwed up the picture quality.

You may also notice that the picture is zoomed in, which is another problem that’s been going on alongside the de-interlacing. Unfortunately, this is still an on-going issue that quite honestly I highly doubt will ever get fixed now. But at least the de-interlacing is fixed...for now that is.

The reason for recording on U&Drama +1 is because it gives a slightly (SLIGHTLY) better picture compared to normal U&Drama. However, I have reason to believe that this may have changed now because, according to the readings on Digitalbitrate.com, the slightly higher bitrate is now on U&Drama and not U&Drama +1...but it seems to keep changing. So for that reason I’m currently recording them on both channels.

@jak.willis

Hi

. . . .  the interlaced file has an "effective" frame rate of 50 "frames" per second because your eyes are seeing 50 fields per second. . . . .

That would apply to the old CRT TV'sb which scanned the field line by line, one field after the other.

However modern TV's convert the interlaced video to progressive as they are a progressive display and you see the movie at a frame rate of 25 fps, it takes 2 fields one top (odd) and one bottom (even) to build the complete image.

See this comment giving an example of what a TFF or Odd field 'image' would look like, the next field of the pair would contain the inverse image where the black lines are amerge the two together any get a full frame.

In marketing speak saying a TV is 50i sounds great, the reality is it is 25 fps, they are not giving you something better.

John EB

@jak.willis @me_again

The BBC does not own the UK terrestrial transmitters and has to bid for channel allocation against competitors. Bandwidth and power are limited as the same frequencies are used by France and countries further afield. The UK TV channels have slightly more bandwidth on Sky. I have no idea if having a U.co.uk account to view those channels on a broadband connection gives a better viewing experience or not. The archive is now cloud based on Amazon servers with the old system now disused. A lot of what was searchable on the BBC website is not longer viewable which is sad as it was a good source of technical information.

All EastEnders episodes were recorded on videotape except anything that involved outside locations that involved film crews and those scenes were shot on film and then placed into the video footage of those episodes. Video Editing back then was anything but simple and anyone interested should watch the Periscope Films video ' "VIDEO TAPE EDITING ” 1960s BBC TELEVISION TECHNICAL TRAINING FILM AUDIO & VIDEO TAPE XD60154' on YouTube.

Ray.

@CubeAce

The BBC does not own the UK terrestrial transmitters and has to bid for channel allocation against competitors

Ok Ray, you've confused me now. I know that SDN is owned by ITV, and transmitter provider Arqiva own Arqiva A and Arqiva B so who owns Multiplexes BBC A & BBC B?

Here's a MP4 snippet render of a conversion to 50 frames per second of the Deint file (00059) using the RIFE plugin of AVISynth. It's not perfect (see the bouncy titles at the start) but does a pretty decent job.

https://drive.google.com/file/d/1iE00wUDCDkxDp8j4BqIHufGhZ4jw-yNh/view?usp=sharing

 

Yes - your render does look a bit better when viewing it on my TV as well.

So, going forward, what exactly is it I need to do to fix these screwed up broadcasts?

Can I do what you did in Magix? Or do I need to use AVI Synth?

Aside from exporting at 50fps instead of 25fps, is there no other way to fix the issue? Simply exporting it as interlaced won't make a difference?