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View Full Version : Absolutely Horrible Scaling/Upconversion in broadcast programming


drbuzz0
29th August 2010, 17:53
I've noticed something rather bothersome when watching HDTV programing: A great deal of up-converted footage is improperly and just plain horribly converted. At times, it's not even properly deinterlaced and thus creates horrible interlace artifacts on the screen.

Obviously, when a program is broadcast in high definition, the footage used is always best sourced from native HD stock. SD programing will never look as good as HD, no matter how much processing and scaling you throw at it. Still, there are times when only SD footage exists and it has to be used for a given program.

I noticed this several times when watching documentaries that contained older video, taken, at the time, with standard definition video cameras. On a program about aircraft on the Discovery HD channel, they repeatedly used footage taken during the first Gulf War in the early 1990's.

Since the footage is SD, it's not going to have the same sharpness and level of detail as HD footage, but it still can be scaled to the higher resolution and, if done properly, ought to look okay. However, when I saw it, it was obvious that it had been scaled (poorly I may add) in combined field mode without any deinterlacing. It had horrible mouseteeth that are damn near impossible to remove after the video has been scaled like that.

I've seen worse, though. On some programing, World War II footage was shown in a similarly badly interlaced and poorly scaled format. This is even more irritating, since the original footage was taken with cinema film (not television) and thus is naively progressive. Whoever edited the program was apparently working with a telecined SD version of the original footage. They should have attempted to obtain a better telecine of the footage at higher resolution, but if that was not possible, they should have at least known enough to detelecin the footage back to progressive before inserting it into an HD program.

Of course, this is also seen when SD programing is aired on HD channels. My local Fox affiliate broadcasts in 720p, but from time to time they show older programing like reruns of 1990's sitcoms, old Simpsons episodes and that kind of thing. Without exception, they're always very very very poorly scaled. They look like complete crap. They look so bad that the quality is considerably better when I switch the channel to my cable's analog SD version of Fox and view the same program as up-converted by my television set.

Then there are those damn black bars on the side that they often insert. This might not bother me so much if half the time they didn't end up getting the aspect ratio wrong anyway. The one example that has to take the cake is a program I saw, while flipping the channels, which was of a widescreen program, letterboxed to 4:3 and then letter boxed again to 16:9. So you had program formatted by adding horizontal letter-boxing and then formatted again by using vertical letter-boxing. What you're left with is the video in a small rectangle in the center of the screen.

What the hell gives? One would think that the editors and broadcast techs who run things would know about interlacing and that you don't convert 480i to 720p without deinterlacing. You certainly don't convert 480i to 1080i without doing anything more than a simple bicubic resize. Don't they have some idea about the issue of resolutions?

Geez! Do the job right! It isn't that hard!

Episodio1
29th August 2010, 18:49
which was of a widescreen program, letterboxed to 4:3 and then letter boxed again to 16:9.

Yes, I've got a few channels doing same: they are broadcasring allways at 16:9, but if there is an old 4/3 movie (with black bars included on tape) they don't switch to broadcasting at 4/3.

But upscaling is good so far.

laserfan
29th August 2010, 20:49
One would think that the editors and broadcast techs who run things would know about interlacing
Yes, first they have to Know, then they have to Care, and finally they have to Do Something About It! ;)

Assuming 1. is a given, then maybe if you make some specific complaints to the Station Manager you can get something to happen with 2 and 3.

Ghitulescu
30th August 2010, 07:47
Based on my experience and learning from various HDTV fora, and occasionally here, most people that own an HDTV receiver (be it SAT, DVB-C or DVB-T2) are extremely keen in downconverting the recordings to SDTV.

Should you be yourself a station manager with a tight budget and see that many people downconvert anyway the programs, would you invest money in a decent upcaler (they can't use the "normal" upscalers, but something 10 fold more expensive), invest money in aquiring a better material for people that claim but actually don't care? I won't think so ;)

Blue_MiSfit
30th August 2010, 08:55
The biggest issues are these

1) Sadly, editors are usually uninformed when it comes to the technical details of the clips they're editing. If their support folks or lack thereof don't do a good job of QCing the source media to identify necessary processing (i.e. pulling out the 3:2 pulldown from your WWII footage), it will NOT happen. The editor will drop it in the timeline and be happy when he finishes his project on time and it renders out successfully (or lays back out to tape without failing). You're lucky if an editor can give you a straight answer about how 3:2 works, and why they shouldn't mix 24p, 30p, and 60i footage in a single project. But that's another raging rant for later.. :)

2) Letterboxing is an awful whore. It depends on the network in question, but many of them are still very concerned with providing users with 4x3 NTSC CRTs the best experience. Thus, they WILL make every single asset 4x3. 16x9? It's getting center cut. If center cutting it destroys logos or important text, it's either not going on the air, or it's being double letterboxed to display correctly on a 4x3 set. If you're EXTREMELY lucky, they'll run it through a Snell / Teranex box and do an adaptive AR conversion. Sadly, these boxes usually cost at least $30k, and up to $150k if you want a top of the line unit that can up, down, cross, and rate convert plus fancy schmancy filtering. That's a tough cookie to swallow unless it's bringing in enough money to pay for itself ;)

People who rage about the black bars you see when a 2.35 movie is presented on a 16x9 screen make me LOL.... :D

2Bdecided
2nd September 2010, 11:47
The arty-types working on programmes really don't understand the technical side much, and lots of NLEs do amazingly stupid things by default.

Interestingly, the BBC HD guidelines specifically say that any SD content must be upconverted properly:

"Particular care should be taken up-converting standard definition material to include in high definition programmes. Only high quality up-conversion equipment should be used. Use of “in VTR” up converters or up conversion using non-linear editing software is not acceptable. This requirement protects the standard definition viewer who will see the standard definition material after multiple conversions."

from http://www.bbc.co.uk/guidelines/dq/pdf/tv/hd_summary_delivery_formats_v1_09.pdf from http://www.bbc.co.uk/guidelines/dq/contents/television.shtml

Cheers,
David.

um3k
2nd September 2010, 16:10
I wonder if they would accept footage upscaled (properly, of course) in Avisynth?

2Bdecided
2nd September 2010, 17:22
I wonder if they would accept footage upscaled (properly, of course) in Avisynth?Probably.

Some SD footage upscaled "properly" looks awful anyway because the original is so old and soft e.g. grainy 16mm film, badly scanned in the 1970s to PAL video, then converted to D3, then ingested onto a server, cropped from 4x3 to 16x9 and finally converted to HD. It doesn't even look good in SD!

(You don't get this much in the USA, but it's very very common in the UK - 16mm film was standard for outdoor TV shooting in the 1970s. The original film was usually destroyed, so all that remains is an analogue composite VT sourced from a really bad telecine mechine).


There are other things I've wondered about on that list - i.e. things that I'm sure you could cheat in AVIsynth or similar.

e.g.

they won't accept 50i>25p conversions, only native shot 25p. It's possible to make 25p from 50i in AVIsynth (and some high-end equipment) that's all but indistinguishable from native 25p.

they won't accept HDV as HD (never mind consumer AVCHD!) - yet with an otherwise decent camera, and some AVIsynth processing to hide any artefacts, how would they know? Certainly not with simple talking head shots.

Cheers,
David.

drbuzz0
31st December 2010, 02:56
Based on my experience and learning from various HDTV fora, and occasionally here, most people that own an HDTV receiver (be it SAT, DVB-C or DVB-T2) are extremely keen in downconverting the recordings to SDTV.



I know. The guy who used to live nextdoor to me got a new HDTV and invited everyone over for a superbowl party. He had the TV hooked up to the box using composite video. I had to gently explain to him that it was not the way to do it. I ended up running home to get some component video cames (still not the best thing to use, but I didn't have any spare HDMI cables to spare.)

He said "Oh, I think you might be right. It does look better like that."

Gser
31st December 2010, 16:15
I know. The guy who used to live nextdoor to me got a new HDTV and invited everyone over for a superbowl party. He had the TV hooked up to the box using composite video. I had to gently explain to him that it was not the way to do it. I ended up running home to get some component video cames (still not the best thing to use, but I didn't have any spare HDMI cables to spare.)

He said "Oh, I think you might be right. It does look better like that."

I swear, people like that make me cry. So before I try to explain anything to them, I tend to huddle in a corner and have a sob. The most difficult part is not sounding arrogant and making them feel like the idiot they are. My grandparents have a HD dvr and a hdtv and they still use scart. I think it would be pointless to try to explain anything to them as my grandma keeps asking me the same questions about her digital camera everytime I see her (Just point and SHOOT goddamnit!).

smok3
31st December 2010, 16:42
guidelines specifically say that any SD content must be upconverted properly:

"Particular care should be taken up-converting standard definition material to include in high definition programmes. Only high quality up-conversion equipment should be used. Use of “in VTR” up converters or up conversion using non-linear editing software is not acceptable. This requirement protects the standard definition viewer who will see the standard definition material after multiple conversions."


what would count as 'properly'?