[jgrg]

I think I've worked out why, in contrast to their studio footage, which looks OK, field reports on Top Gear look bad. I recorded a clip and looked at it on my Mac. The video player doesn't, as far as I can tell, do any de-interlacing. The studio footage showed the combing you expect from interlaced video. There is, however, no combing in the reports, which look pixelated, with jagged edges. Using Apple's Pixie tool to look at the pixels in detail I can see that it looks like the report video has been de-interlaced by line doubling of fields. So to the Edge it is progressive, and it looks particularly bad when it blows this up to 1080p to fit my screen since the scaling algorithm makes the jagged edges of diagonals more pointy.

I attach two enlargements from my clip. The first are the hands of someone in the studio audience clapping, so you can clearly see the combing. The other is from a report, and is the edge of a box in the back of a veteran car from a static shot, where you can very clearly see the line doubling.

[eiren]

I get this in the Snuff Box DVD (also from the BBC Snuff Box: Michael Cumming: Amazon.co.uk: DVD)

Basically it's originally recorded as video and then it's converted to give it a film-like look (as per Top Gear) so they deinterlaced it and just used every other frame. As such, the deinterlacing used to do this was of poor quality and resulted in the jaggies you see on most diagonal edges.

What worked to get rid of it was to switch EDGE over into Game mode, and that overrode the problem. This forces the EDGE to construct each output frame from only a single input field using its deinterlacer's diagonal processing. The downside to this is that you may lose a little detail (or not, depending on how the original deinterlacing was done) and it will introduce some flicker into the image. It will get rid of the jaggies, however.

OR you can just put it down to botched source material.

[petes]

Originally Posted by jgrg

I think I've worked out why, in contrast to their studio footage, which looks OK, field reports on Top Gear look bad. I recorded a clip and looked at it on my Mac. The video player doesn't, as far as I can tell, do any de-interlacing. The studio footage showed the combing you expect from interlaced video. There is, however, no combing in the reports, which look pixelated, with jagged edges. Using Apple's Pixie tool to look at the pixels in detail I can see that it looks like the report video has been de-interlaced by line doubling of fields. So to the Edge it is progressive, and it looks particularly bad when it blows this up to 1080p to fit my screen since the scaling algorithm makes the jagged edges of diagonals more pointy.

I attach two enlargements from my clip. The first are the hands of someone in the studio audience clapping, so you can clearly see the combing. The other is from a report, and is the edge of a box in the back of a veteran car from a static shot, where you can very clearly see the line doubling.

In general, Top Gear just looks horrible whatever you do to it - which is pity. Once you've seen it, you want to look at the lovely automobilia (if such a word exists), but can't help looking at the horrible stepping in the image of the A-pillar on that Veyron - grrrrr

[mackie1]

I noticed this with Clarkson's Thriller DVD. I guess they use the same production method for these DVDs. I was a little worried by it as it was the first DVD I tried in my new Oppo DVD player and it looked somewhat crap!

[Liam @ Prog AV]

Why oh why are Top Gear still filming in SD?? The Polar Expedition one (which was shown in HD) had some truly amazing footage - with all these sexy cars and cool camera shots surely it needs to be done in HD.

[jgrg]

Originally Posted by eiren

What worked to get rid of it was to switch EDGE over into Game mode, and that overrode the problem. This forces the EDGE to construct each output frame from only a single input field using its deinterlacer's diagonal processing. The downside to this is that you may lose a little detail (or not, depending on how the original deinterlacing was done) and it will introduce some flicker into the image. It will get rid of the jaggies, however.

That's a great tip, thanks. My work around had been to put my satellite receiver into 1080i, but the Edge in Game Mode looks better. Have just ordered a universal remote, so I should be able to use the discrete codes for Game mode on/off instead of hunting through several layers of menus.

Also sent a feature request to DVDO to add a "force video mode" option to the Edge.

[jgrg]

Originally Posted by Liam @ Prog AV

Why oh why are Top Gear still filming in SD?? The Polar Expedition one (which was shown in HD) had some truly amazing footage - with all these sexy cars and cool camera shots surely it needs to be done in HD.

Yes, since Top Gear is one of the BBC's most popular shows, surely it will be near the top of the list for HD production.

I don't understand why these shows can't shoot in progressive SD video. Would double the vertical resolution compared to how they are currently doing it. Maybe such cameras don't exist?

[Barcoing Mad]

I suspect that the Top Gear production team are the most stupid.............in the world.

[jgrg]

Originally Posted by Barcoing Mad

I suspect that the Top Gear production team are the most stupid.............in the world.

They're not the only offenders. I've seen the same thing with Five's Gadget Show reports, and the Holby City Christmas special (might also apply to all of their other episodes, but I don't watch it). I wonder if it is the same production company?

[NicolasB]

Originally Posted by jgrg

I don't understand why these shows can't shoot in progressive SD video. Would double the vertical resolution compared to how they are currently doing it. Maybe such cameras don't exist?

Maybe they feel that the higher frame rate (and consequent improvements to smooth motion) are worth the loss of vertical resolution? It's by no means guaranteed that 576p/25 will look better than 576i/50.

Using an interlaced source doesn't usually halve the vertical resolution, anyway. You only drop all the way to half-res if every pixel in the frame is in motion (e.g. if the camera is panning). If part of the picture is the same as it was one frame ago then (assuming correct deinterlacing) you get the same resolution within that portion of the picture as you would with a progressive source.

[jgrg]

Originally Posted by NicolasB

Maybe they feel that the higher frame rate (and consequent improvements to smooth motion) are worth the loss of vertical resolution? It's by no means guaranteed that 576p/25 will look better than 576i/50.

Using an interlaced source doesn't usually halve the vertical resolution, anyway. You only drop all the way to half-res if every pixel in the frame is in motion (e.g. if the camera is panning). If part of the picture is the same as it was one frame ago then (assuming correct deinterlacing) you get the same resolution within that portion of the picture as you would with a progressive source.

Yes, sure. Was just thinking that in the case of this botched footage, where they clearly want the "film look", why not shoot progressive instead of discarding half the fields to make rubbish line doubled progressive from interlaced video?

[jgrg]

Originally Posted by jgrg

They're not the only offenders. I've seen the same thing with Five's Gadget Show reports, and the Holby City Christmas special (might also apply to all of their other episodes, but I don't watch it). I wonder if it is the same production company?

Yes, Holby City, on now, is the same. Very nasty.

[Barcoing Mad]

James and Oz boozing around Britain last night...very, very nasty both over HDMI (576p) and with interlaced RGB over scart in a C2. No-one should be blaming their VPs.

[eiren]

Channels seem to show things slightly different too. Although I am not a fan, when Neighbours was shifted from the BBC to Channel 5... it seems to have been converted from video to that film-esque look by Channel 5.

The same happened when they shifted Home & Away over from ITV.

I'm quite ashamed to admit to have noticed this

[kingfats]

Originally Posted by eiren

Channels seem to show things slightly different too. Although I am not a fan, when Neighbours was shifted from the BBC to Channel 5... it seems to have been converted from video to that film-esque look by Channel 5.

The same happened when they shifted Home & Away over from ITV.

I'm quite ashamed to admit to have noticed this

I noticed that as well,my wife watches it though not me.

[HDCriticalFan]

I've noticed this effect too (some time ago) - and I actually took the time to complain. I think I have brought it up with the Beeb and C5 for Top Gear and Fifth Gear respectively.

It just looks awful.

After a round of correspondence I got the feeling that they were writing me off as a nutter. Apparently it is an "artistic choice". Fair enough, if they use is occasionally (like doing a piece in black and white a la Mr Cholmondley-Warner) ... but not for every outside report !

As a previous poster noted, it is particularly galling when they start off in the studio standing next to a beautiful car and gush about how beautiful it is and then say "Now watch it in action" and we cut to a lego version of reality where all of the diagonals and curves are jagged.

I don't have any specialist, configurable, scaling equipment at my disposal so on my plasma screen I end up comparing :

- 576i50 "intelligently" scaled up (without jaggies) to over 1,000 smooth lines

- 288p25 "foolishly" scaled to over 1,000 lines (to fill the screen) with each "jag" is clearly made up of 4 screen pixel lines !

It's easy to demonstrate - just pause your Sky+ to see the effect.


This has reminded me that back in 2002 I watched a BBC documentary on my old 32 inch CRT and saw this effect. I kept the programme on my Sky+ and re-watched it when I got a plasma screen a few months later. I foolishly hoped to see some improvement. Well I did ... kinda. The jagged effect was much more clearly presented on the larger plasma screen !




Regards

HDCriticalFan

I am a fan ... but I remain critical.

[NicolasB]

Originally Posted by HDCriticalFan

It's easy to demonstrate - just pause your Sky+ to see the effect.

Everything looks bad if you pause Sky+.

[HDCriticalFan]

Everything looks bad if you pause Sky+.

I do beg your pardon, I wasn't being clear there.

What I meant to say was, the visual effect of the Top Gear et al "filmic effect" can be recreated on good video material by pausing a Sky+.

As I'm sure most people here know, when in pause mode a Sky+ holds a single field (not a complete frame). My TV set up treats this as if it was a video stream (albeit of a static image) at 288p25.

It does indeed look bad.




Regards

HDCriticalFan

I am a fan ... but I remain critical.

[mikelj]

Sorry guys, I'm afraid I'm being a bit dim here, but are you saying that the material is film shot at 288p25 and then de-interlaced to 576i@50Hz by simply doubling each line?

Funnily enough, I was watching an old repeat of Top Gear (Clarkson looked young!) on Dave the other day on my 14" CRT in the kitchen and could see jaggies all over the place; not good when its only a 14" screen you're viewing!

[eiren]

Originally Posted by HDCriticalFan

I do beg your pardon, I wasn't being clear there.

What I meant to say was, the visual effect of the Top Gear et al "filmic effect" can be recreated on good video material by pausing a Sky+.

As I'm sure most people here know, when in pause mode a Sky+ holds a single field (not a complete frame). My TV set up treats this as if it was a video stream (albeit of a static image) at 288p25.

It does indeed look bad.




Regards

HDCriticalFan

I am a fan ... but I remain critical.

Yeah pausing Sky or Freeview will show exactly that, one field at a time. The BBC have taken these and converted them over, so they're locked into the picture. The jagged edges are then encoded right into the picture.

[jgrg]

Originally Posted by mikelj

Sorry guys, I'm afraid I'm being a bit dim here, but are you saying that the material is film shot at 288p25 and then de-interlaced to 576i@50Hz by simply doubling each line?

Funnily enough, I was watching an old repeat of Top Gear (Clarkson looked young!) on Dave the other day on my 14" CRT in the kitchen and could see jaggies all over the place; not good when its only a 14" screen you're viewing!

Yes, almost. I'm sure they shoot it at 576i@50Hz, but during editing it is converted to 288p25, and then re-interlaced to 576i@50Hz by line doubling. But, of course, any decent video processor will detect that it is not actually interlaced video, and reconstruct the progressive frame which is at half resolution and therefore pixelated and jaggy.

[choddo2006]

You can't force the EDGE into video mode, right?

I wonder what happens on processors where you can do that. I would imagine it still looks jaggy.

[mikelj]

The video mode processing on Pioneer is pretty good and it looks very jaggy on my 507XD.

[Barcoing Mad]

I had a bitch to the Beeb yesterday (before seeing that HDCF had tried). Suggest everyone has a moan. Maybe moan directly to Top Gear as well (At least the presenters do try to under technical stuff, even if the production team all have joint honours in media studies and ancient Urdu pottery).

[HDCriticalFan]

the production team all have joint honours in media studies and ancient Urdu pottery

Chortle, chortle.


You've reminded me of a post I saw a long time back. A video professional had posted about the time he was doing the editing for an artsy director. Apparently the filmic effect can only be added after all the editing is done and so the "first draft" of the programme was shown in a viewing room at full resolution (i.e. top quality). This wasn't the effect the director was hoping for (she wanted it to look really classy and "filmic") and she was in tears as the technician tried to explain that he could ruin the picture to her satisfaction later !




Regards

HDCriticalFan

I am a fan, but I remain critical.

[eiren]

I've sent a link to this thread to Andy Quested, BBC Principal Technologist, HD, BBC FM&T. If he's nothing to do it, I am sure he'll be able to highlight it to the relevant person at the BBC.

Here's his excellent blog:

BBC Internet Blog

[jgrg]

Originally Posted by choddo2006

You can't force the EDGE into video mode, right?

I wonder what happens on processors where you can do that. I would imagine it still looks jaggy.

No, but I have sent a feature request to DVDO asking for a "force video mode" setting.

Video mode smoothes out all jaggies. I guess this is why most people don't notice; their TVs aren't capable of correctly detecting progressive material, so are stuck in a video mode all the time.

Putting the Edge into Game mode smoothes out the jaggies.

[eiren]

Video mode wouldn't help this scenario. Only GAME mode will construct each output frame from only a single input field using the EDGE diagonal processing when deinterlacing.

[scumball]

You can't produce SD progressive on SD production camera's. SD production is based on Digital Betacam equipment which is an interlaced tape format.

They may as you say be deinterlacing the footage in an edit suite before laying back out to interlaced master tape.

The file stored on the server for transmission will most likely be an interlaced MPEG2 (some example of what can be used are QT Reference files for Omneon servers @ 12mb/s or MXF D10 @ 30mb/s for Quantel ) and then final 'live' encode out to the MUX will be interlaced MPEG2 @ around 4mb/s.

Some channels I believe transmit half resolution and even quarter resolution MPEG2 which are then upscaled back up to 720x576 by the decoder. Have you seen BBLB on E4 - absolutely shocking, like watching a YouTube video at 42"....


@mikelj - ...and god knows what they are doing at that DAVE channel. I watched QI the other day and the framerate looked converted and there was pillarboxing and letterboxing going on....a shambles.

@ eiren - The new series of the Oz soaps (Neighbours & Home & Away) are shot in HD now - this probably happened at the same time as the move as I'm sure BBC and ITV probably had deals up to the end of a particular series.

[bigtim]

"Filmised" video google or wiki it.

Seems to be seeping into more and more shows. Doctor who too but doesn't seem so bad on that.