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So a board I frequent has members who constantly post video clips referenced as "1080p" when said video clips have never been released on HD DVD or Blu-Ray. Some board members defend this by claiming "someplace in Europe/Scandinavia" broadcast them in 1080p".


No proof of said broadcast is ever stated and questions about the validity of the 1080p broadcasts are usually met with banishment. Help me out with some logical arguments I can link to. Here is a typical question and response.

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Seeing that the resolution is 1920x816, doesn't that make it 816p and not 1080p? Because I thought 1080p meant it was 1920 x 1080.
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1080p is a marketing buzzword now for HDTVs carrying 16x9 ratios with the resolution of 1920x1080 to fill up the 16x9 dimension. But many "theatrical" films and especially epic ones like Lord of the Rings and Star Wars were shot at a wider aspect ratios of 2.35:1 or 2.42:1 , so this is wider than your 16x9 screens can fill up. So you will get black bars at the top and bottom of your screens; this is why you will see many movies here with 1920x816 description. This is still called 1080p but it is not filling up your HDTV completely....maybe you could say it has less vertical resolution but it still carries 1920 horizontal lines, thus it is called 1080p.
 

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We are being punked, right? But I will answer this as if it is a real question.


The "p" or "i" refers to how the picture is displayed, not the lines of resolution. "i" refers to interlace scanning of the picture where the odd lines are scanned and then the even lines are scanned and then reassembled correctly in the mind. "p" refers to the progressive scanning of the picture where the lines are scanned in order and then reassembled in order. You can have 480i or 480p, 720i/720p or 1080i/1080p. Same number of lines, just different in how they are displayed.


This 1920x816 could be the actual picture area that has usable information if the image has a 2.35 aspect instead of a 1.85 aspect, but the picture is transmitted as a 1920x1080 and you have black bars in the other 264 lines, with 132 lines above the image and 132 lines below the image. Now it is a whole 'nuther thing whether it is "p" or "i'.


Progressive scan takes a larger data payload than interlace, almost double in size. In the US, terrestrial transmission of 1080i is the current limit due to bandwidth restrictions in the RF transmission system. Satellite is technically unlimited but US satellite companies chose to limit to 1080i to reduce bandwidth demand.


Europe uses a different terrestrial broadcast system than the US and it has a slightly larger bandwidth and I suppose it "might" be able to transmit 1080p with it, I haven't heard of a European terrestrial channel doing it since most European terrestrial channels do not broadcast HD of any kind at this time. European satellite may do 1080p since that is where the majority of their HD is broadcast from, but I have no first hand knowledge they do or don't.
 

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foxeng - Can you generally expect that the PQ of a 1080i HD broadcast will be better when viewed on a 1080p HDTV that it is when viewed on an old standard 720p set? I have seen 1080p Blu-Ray disks shown on 1080p sets and it's wonderful but I was wondering whether any of that transfers to 720p and 1080i material seen OTA or via cable or satellite?


Having asked this, let me hasten to add, I understand that PQ is, inevitably, a matter of opinion.
 

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Quote:
Originally Posted by foxeng /forum/post/14229292


We are being punked, right? But I will answer this as if it is a real question.


The "p" or "i" refers to how the picture is displayed, not the lines of resolution. "i" refers to interlace scanning of the picture where the odd lines are scanned and then the even lines are scanned and then reassembled correctly in the mind. "p" refers to the progressive scanning of the picture where the lines are scanned in order and then reassembled in order. You can have 480i or 480p, 720i/720p or 1080i/1080p. Same number of lines, just different in how they are displayed.


This 1920x816 could be the actual picture area that has usable information if the image has a 2.35 aspect instead of a 1.85 aspect, but the picture is transmitted as a 1920x1080 and you have black bars in the other 264 lines, with 132 lines above the image and 132 lines below the image. Now it is a whole 'nuther thing whether it is "p" or "i'.


Progressive scan takes a larger data payload than interlace, almost double in size. In the US, terrestrial transmission of 1080i is the current limit due to bandwidth restrictions in the RF transmission system. Satellite is technically unlimited but US satellite companies chose to limit to 1080i to reduce bandwidth demand.


Europe uses a different terrestrial broadcast system than the US and it has a slightly larger bandwidth and I suppose it "might" be able to transmit 1080p with it, I haven't heard of a European terrestrial channel doing it since most European terrestrial channels do not broadcast HD of any kind at this time. European satellite may do 1080p since that is where the majority of their HD is broadcast from, but I have no first hand knowledge they do or don't.

There is no 1080p broadcast anywhere in the world period. If somebody posts any clips and claim 1080p, they are lying. Slightly higher bandwith on DVB-T (only in 64QAM mode, in 16QAM mode it is lower) when using HD does not equal 1080p, and many times they have to increase FEC which lowers usable bandwith due to difficulty of reception, like in Australia.


There are very few DVB-T HD broadcasts, like in Sweden that uses 720p/50Hz and I believe in France also. In UK they had trials by BBC, but I do not think there is any DVB-T HD now.


European satellite service have less bandwith than D* by itself. Of course they used to run 2 or 3 channels at higher bandwith in the beginning, but now they are lowering it, to fit more channels.
 

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Quote:
Originally Posted by mullet34 /forum/post/14229075


So a board I frequent has members who constantly post video clips referenced as "1080p" when said video clips have never been released on HD DVD or Blu-Ray. Some board members defend this by claiming "someplace in Europe/Scandinavia" broadcast them in 1080p".


No proof of said broadcast is ever stated and questions about the validity of the 1080p broadcasts are usually met with banishment. Help me out with some logical arguments I can link to. Here is a typical question and response.

You can tell them they are lying. THERE ARE NO 1080p BROADCASTS ANYWHERE IN THE WORLD. These are 1080i captures deinterlaced to 1080p on a computer. Besides they suck anyway as all European broadcasts from film have the so called PAL sound speed up. Can you tell us what board is this or link to it.
 

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Quote:
Originally Posted by gwsat /forum/post/14229478


foxeng - Can you generally expect that the PQ of a 1080i HD broadcast will be better when viewed on a 1080p HDTV that it is when viewed on an old standard 720p set? I have seen 1080p Blu-Ray disks shown on 1080p sets and it's wonderful but I was wondering whether any of that transfers to 720p and 1080i material seen OTA or via cable or satellite?


Having asked this, let me hasten to add, I understand that PQ is, inevitably, a matter of opinion.

Not really up for debate. All things being equal, 1080i will display better on a 1080 set than a 720 set. There's no way around the fact that you are losing resolution when downconverted.


The debate is generally involving the significance of the benefit of 1080p vs. 1080i material when displayed.
 

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Quote:
Originally Posted by gwsat /forum/post/14229478


foxeng - Can you generally expect that the PQ of a 1080i HD broadcast will be better when viewed on a 1080p HDTV that it is when viewed on an old standard 720p set? I have seen 1080p Blu-Ray disks shown on 1080p sets and it's wonderful but I was wondering whether any of that transfers to 720p and 1080i material seen OTA or via cable or satellite?

Generally speaking, yes because you have 1080 lines to play with instead of 720. Now WILL IT look better, that will depend on many variables of the display device. IMHO, generally speaking, yes. If I personally were buying today, I would go for 1080p. YMMV.
 

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Quote:
Originally Posted by CKNA /forum/post/14229562


You can tell them they are lying. THERE ARE NO 1080p BROADCASTS ANYWHERE IN THE WORLD.

Totally wrong.


There are 1080p broadcasts every minute of every day on most 1080i channels. Most of the content on those channels is filmed or recorded on HD video at 1080p/24 and telecined, NOT interlaced, to 1080i. Your set should recognize the pulldown pattern and reconstruct 1080p/24 perfectly.


In terms of resolution, there is no difference between this process, and what you see on a blu-ray disc. If you have a 1080i BD player, your TV will recognize the signal in exactly the same way, and also reconstruct 1080p/24.


You are watching 1080p most of the time, except for live/news programs and a few other types of shows that are shot using interlaced video, such as low budget documentaries.


There is nothing to debunk, because it's not a myth.
 

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Quote:
Originally Posted by gwsat /forum/post/14229478


Can you generally expect that the PQ of a 1080i HD broadcast will be better when viewed on a 1080p HDTV that it is when viewed on an old standard 720p set?

This issue gets pretty confusing because TV manufacturers have decided to use "1080p" as the way to describe a screen that has 1920x1080 pixels. To make things easier to understand, you can pretty much just drop the "p" from the descriptions and just focus on the native resolution of the display. A 1080i broadcast has a resolution of 1920x1080 -- the same as a 1080p screen -- so you will get a better picture when using a so-called 1080p display to watch 1080i material. You are watching it in it's native resolution -- though to truly see it native you will usually have to switch the set to a mode that cuts all overscan, and maps the pixels dot-for-dot -- usually called the "1:1" mode or "HD Size"). To view a 1080i broadcast on a panel that has 720 resolution (usually 1366x768), the image must be down-rezzed.


To be fair, it can still look really good, and if the screen is small enough (like, 32-inches or below), the pixels are already so small at 720 that the benefit of making them even smaller to accommodate the additional pixels is pretty hard to see.
 

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Quote:
Originally Posted by CKNA /forum/post/14229540


European satellite service have less bandwith than D* by itself. Of course they used to run 2 or 3 channels at higher bandwith in the beginning, but now they are lowering it, to fit more channels.

In the UK we use H264 encoding on satellite, with BBC HD running at around 16.5Mbs in H264 (which should deliver higher quality than MPEG2 at the same data rate), and some Sky channels are running in excess of 20Mbs.


Sky are using DVB-S2 - which gets more data per transponder than DVB-S - with their high quality services running at 2 streams per transponder, with their lower quality services running at 3 streams per transponder.


ITV HD, BBC HD and Luxe TV HD are running on DVB-S transponders (less digital bandwith per transponder) as they are sharing with SD services (or in the case of ITV HD - an EPG stream for SD receivers on freesat)
 

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I suspect the 1080p clips are 1080p sources broadcast in 2:2 1080i H264, recordings in Europe, but re-encoded in progressive after de-interlacing.


Many of the European HD stations are running at high data rates in H264 - and broadcast OAR, which means not all the 1080 lines are active (as some contain letterbox black video). When re-encoding you'd be just as well to only encode the active portion, hence whilst the TX master may well have been a 1080p VT (most movies are delivered on 1080/25p HD Cam SR tape AIUI), the final encode may be shallower.


As others have said - whilst 1080/24p and 1080/25p are widespread production formats - and in some cases are used for delivery - they are not broadcast formats. However 1080i can carry both losslessly. However AIUI it isn't widespread to losslessly convert this to a 1080p compressed signal in the MPEG2 or H264 domain - though with the progressive flags it may be that effectively the 1080i H264 signal is internally progressive. (The BBC use MBAFF and Sky use PAFF extensions in H264 to allow a switch between progressive and interlaced flags within an interlaced stream on a macro-block by macro-block or field-by-field level I believe?)
 

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Quote:
Originally Posted by CKNA /forum/post/14229562


You can tell them they are lying. THERE ARE NO 1080p BROADCASTS ANYWHERE IN THE WORLD. These are 1080i captures deinterlaced to 1080p on a computer.

Yep - but there ARE 1080/25p productions shot at 1080/25p (or 25Hz film - as all TV film in Europe is shot 25fps not 24fps). Most UK HD drama is shot 1080/25p, as is a lot of documentary.


These can be broadcast losslessly in 1080/50i - though not converted losslessly to a compressed 1080/25p format. (Though they can be converted losslessly in the baseband domain)

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Besides they suck anyway as all European broadcasts from film have the so called PAL sound speed up. Can you tell us what board is this or link to it.

Only movies shot on film at 24fps have PAL speed-up.


Film shot in Europe for TV productions is not shot at 24fps, it is shot at 25fps, and as a result film content shot for TV is NOT sped up...


As a result a LOT of film broadcast in Europe is not sped up - it is broadcast at its original 25fps acquisition rate. (TV Drama, TV Documentary etc. shot on film is 25fps)


What IS true is that 1080/25p isn't used as an HD transmission format. However with the modern compression schemes, progressive sources can be exploited and progressive redundancy (no motion between fields in the same frame) employed within an interlaced system.
 

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Quote:
Originally Posted by CKNA /forum/post/14229540


There are very few DVB-T HD broadcasts, like in Sweden that uses 720p/50Hz and I believe in France also. In UK they had trials by BBC, but I do not think there is any DVB-T HD now.

Sweden are currently running DVB-T 720/50p H264 for SVT HD (sharing with a single 576i MPEG2 SD Finnish language service). However AIUI SVT HD will be shifting to a DVB-T2 mux in VHF (as a nationwide SFN ISTR) at some point in the future... (So any DVB-T HD receivers will be obsolete - as no DVB-T2 consumer silicon yet exists - the standard was only finalised last month)


The UK ceased the London DVB-T HD trials (BBC HD on one mix, ITV/C4/Five shared a second mux on a time-exclusive basis)


The BBC have now started a trial of DVB-T2 in Guildford (where their MISO and MIMO trials took place - where dual horizontal and vertical polarisation was tested) DVB-T2 should deliver approx 32Mbs per 8MHz mux - without any MIMO/MISO techniques AIUI.
 

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Quote:
Originally Posted by sneals2000 /forum/post/14230731


As others have said - whilst 1080/24p and 1080/25p are widespread production formats - and in some cases are used for delivery - they are not broadcast formats. However 1080i can carry both losslessly. However AIUI it isn't widespread to losslessly convert this to a 1080p compressed signal in the MPEG2 or H264 domain - though with the progressive flags it may be that effectively the 1080i H264 signal is internally progressive.

Inverse telecine is a very common feature on American HDTVs; most will either do it automatically always or have a feature that turns it on and automatically senses the type of input.


1080i/60 broadcasts will get deinterlaced if they carry interlaced video content, but inverse telecined back to 1080p/24 if they carry telecined film content.


This process does not require flags, since with 3:2 pulldown it is very easy for software to recognize the unique pulldown pattern after seeing only a few frames and to distinguish it from video that is interlaced every frame.


With 50i transmissions this would no doubt be a lot harder since every frame is interlaced.
 

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Quote:
Originally Posted by nm88 /forum/post/14230876


Inverse telecine is a very common feature on American HDTVs; most will either do it automatically always or have a feature that turns it on and automatically senses the type of input.


1080i/60 broadcasts will get deinterlaced if they carry interlaced video content, but inverse telecined back to 1080p/24 if they carry telecined film content.

Yep - 1080/50i to 1080/50p via 25p is a common feature on European HDTVs.

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This process does not require flags, since with 3:2 pulldown it is very easy for software to recognize the unique pulldown pattern after seeing only a few frames and to distinguish it from video that is interlaced every frame.


With 50i transmissions this would no doubt be a lot harder since every frame is interlaced.

Yep - though AIUI many HD displays in Europe also do this, it is a bit more complex without a redundant field to track.


Most H264 compression encoders used for Europe HD broadcasts also utilise progressive source detection (and static interlaced content is also treated similarly - in some cases on a block by block basis) - but this is only for use within the compression scheme - the interlaced video is reconstructed.
 

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To summarize:


1: No 1080/50P or 1080/60P broadcasts anywhere yet. 1080/50P and 60P may become production standards in the future.


2: 1080/24P and 1080/30P can be broadcast via 1080/60i and the progressive information will stay mostly in tact using "inverse telecine" de-interlacing, especially if repeat flags are used in the MPEG stream. The same is true for 1080/25P in 1080/50i.


3: Almost all pixel based displays are progressive in nature and require interlaced images to be de-interlaced. There's a wide range of sophistication for this process. 1080i images will (in theory) be sharper on a 1080P display as it has the native pixel count (no interpolation required). A 720P image on a 1080P display should have little difference in sharpness compared to one with native resolution provided there is high quality scaling which in large part depends on high quality FIR filters. There is really never a 1:1 relationship between imager pixels, recorded pixels and display pixels as low pass filters are required on both ends. The depth of modulation at the pixel frequency (1/2 sample rate) is zero (nyquist limit). Add compression on top.


Not much more than that.
 

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Quote:
Originally Posted by TVOD /forum/post/14230926


1: No 1080/50P or 1080/60P broadcasts anywhere yet.

Why would there be? Are there any 1080/50p or 1080/60p sources to broadcast?
 

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Not really. Some cameras are capable of outputting it. On SR tape there is dual link recording so it's possible but not really practical. We're still at the point of making 1080 50i/60i 4:2:0 broadcasts mainstream.
 

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Yep - some HD Cameras (Sony HDC-1500s, ThomsonGrassValleyPhilips LDK 8000s) will output dual-link 1080/50p and 1080/60p via a pair of HD-SDI outputs at the camera head, but they don't yet send this down their standard camera cables, so it isn't available in the OB or studio gallery, only locally at the camera head. Fine for D-cinema overcranking but not useful for multi-camera production - and not a requirement for regular drama as that is happy with 24p/25p motion.


3Gbs infrastructure (routers particularly) are becoming available that allow these sources to be carried around a truck or facility via a single cable, without requring the dual-linkage. Mezzanine compression, like Dirac Pro, will also allow 1080/50p and 1080/60p to be carried via regular 1.2Gbs HD-SDI. However AIUI not a huge amount of other kit (mixers, servers, VTRs etc.) in the wild support this.


However AFAIK no-one is yet doing this for general production - so 1080/50p or 1080/60p full production is yet to become a reality.


Some are questioning if it will ever be - as not even the recent European HD standards support it for broadcast (and neither does the standard Blu-ray format)


If 1080/50p and 1080/60p require new standards for transmission and pre-recorded distribution, then unless file-based delivery or IPTV suddenly become huge mainstream technologies, it is more likely that a higher resolution format will become the "next big thing" in HD.
 
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