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1080i HD - is it converted to 25 or 50 frames p/s? |
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#51 |
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Yes the transmission method is 1080 50 i but the source material is very often 25 PSF. Nearly always used for drama and has been inapropriately used on things like Electric proms and others like Michael Macintyre IIRC. It suffers from motion judder, but is very easy to deinterlace as you can simply stitch the two fields back together.
My question to you is if the sport (for example) produced at 50i because it has smoother motion, is simply deinterlaced into one frame 25 fps, why wouldn't it's motion suddenly suffer from the judder that afflicts film/25 psf? Can you see it's temporal resolution would be lost? That really doesn't appear to be the case on my non-frame interpolating plasma. It depends how the picture is de-interlaced. |
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#52 |
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Two fields derived from the same source as in a telecine conversion of a frame of film is effectively the same as 1080p25 as there is no motion between the two fields.. Simply building the two fields into a frame buffer will give the same result as a 1080p25 signal.
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#53 |
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Surely that is not really accurate since interlaced content has fields not frames? My question was how this is rendered by displays- looking at the info from the Microsoft EVR renderer it is stating I am achieving 50fps on all TV, including 1080i, it only drops to 23.97/25/29.97 on progressive material, including iplayer. Presumably if I could receive the german HD channels I would get real 50fps (720p).
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#54 |
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A 1080i signal has sufficient real data to provide a full frame every 1/25 sec no more and no less.
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#55 |
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Are you saying the Microsoft codec in W7 and ffdshow are unusual in outputting 50fps for all interlaced PAL material? Are there any STBs/TVs that do not do this?
If you provided 50fps most TV's couldn't display it, and certainly not via SCART or AV. |
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#56 |
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Amost all of them don't do it - do any?.
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#57 |
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And Sky, Virgin, Freesat etc. Only broadcast in 720p.
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#58 |
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As I said the 50i advantages for motion portrayal are not lost after deinterlacing on my plasma. How would that be the case if the two 50i fields were simply combined into one 25frame\sec?
So they don't usually deinterlace in this way, it suffers too much from the loss of vertical resolution. |
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#59 |
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If you retain 50 fields ps and show them all as frames (by stretching them vertically) you will retain the motion but lose out on vertical resolution as each field has about half the vertical resolution of a complete frame. Yep, a mere 540 lines/pixels or so.
So they don't usually deinterlace in this way, it suffers too much from the loss of vertical resolution. |
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#60 |
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If you provided 50fps most TV's couldn't display it, and certainly not via SCART or AV.
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But thats only the case if you do it by simplistic bob.
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#61 |
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An active matrix display has a transistor for each and every on screen pixel connected to the memory buffer. They can all be turned on at the same time, Each transistor delivers 24 bits of video info (8 for each of red green and blue making around 64 miliion possible colour variations). This transfer happens as near instantaneous as is possible. When compared to the 1/25 sec the frame will be displayed it's instant.
Now who's laughing FYI, you can't even represent a single bit with one transistor, let alone 24-bits. |
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#62 |
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Obviously not through Scart as you can't output a progressive signal through that
. |
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#63 |
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But thats only the case if you do it by simplistic bob.
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Yes, I think most decent STBs/TVs/HTPCs will use something better i.e. adaptive, motion adaptive or vector adaptive deinterlacing in order of sophistication, which I think all involve the framerate doubling.
To imply that all the motion information and all the spatial resolution can be retained when deinterlacing (as has been implied once or twice in this thread) is plain wrong. |
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#64 |
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SCART is just a physical connection standard - it does not determine any signal characteristics. It can support Progressive display signals - in fact there is no reason (other than manufacturers protecting their revenue streams) why SCART can not be used for component HD signals.
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To imply that all the motion information and all the vertical resolution can be retained when deinterlacing (as has been implied once or twice in this thread) is plain wrong.
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#65 |
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Obviously not through Scart as you can't output a progressive signal through that
.Yes, I think most decent STBs/TVs/HTPCs will use something better i.e. adaptive, motion adaptive or vector adaptive deinterlacing in order of sophistication, which I think all involve the framerate doubling. I am not positive as to what my plasma (non frame interpolating) is doing with the deinterlacing.My question is, as I asked earlier, if sport (for example) produced at 50i because it has smoother motion (which it very obviously does compared to 25 psf or film material), simply has the two fields deinterlaced into one frame 25 fps (bob or weave), why wouldn't it's motion suddenly suffer from the judder that afflicts film/25 psf? |
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#66 |
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Nope, not laughing any more, just hysterical, but also saddened by the way some people who have no knowledge of anything beyond what they read on Wikipedia like to spew all over forums like this in vain attempt to feel they have a modicum of significance in the world.
FYI, you can't even represent a single bit with one transistor, let alone 24-bits. ![]() A single transistor is used to turn a led on and off connected to a fibre optic cable to deliver 5.1 channels of audio information, it's called S/Pdif. A mini versiom of the system used in world wide communication systems..The data you get from any transmission is also serial in nature every byte of data follows the other. If anyone is hysterical it's me, the depth of your ignorance frankly amazes. For info even the the basic sata interface can deliver 1.5 Gbit/s, I leave it to you to work out how long it takes to transfer 24 bits
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#67 |
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I will put my hands up here,
I am not positive as to what my plasma (non frame interpolating) is doing with the deinterlacing.My question is, as I asked earlier, if sport (for example) produced at 50i because it has smoother motion (which it very obviously does compared to 25 psf or film material), simply has the two fields deinterlaced into one frame 25 fps (bob or weave), why wouldn't it's motion suddenly suffer from the judder that afflicts film/25 psf? The entire rumours about sport are because some HD programming in the states is filmed and broadcast at 720P50, which gives a higher frame rate - 'supposedly' better on fast moving action. |
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#68 |
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Sport isn't produced here at 50fps, it's produced using the same HD cameras as anything else, 25fps.
The entire rumours about sport are because some HD programming in the states is filmed and broadcast at 720P50, which gives a higher frame rate - 'supposedly' better on fast moving action. |
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#69 |
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I don't think only in the US sport is filmed at 720p50/60,
obviously 720P60 - but same principal.Quote:
I also doubt any sport is filmed at 25 frames progressive as it would look hopelessly jerky. |
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#70 |
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No, it's filmed at 1080i50 - 25fps - but 1080P25 wouldn't look any different, exact same frame rate on the screen.
. 50 fields per second are recorded and de-interlacing basically uses various different methods, the best accounting for motion, to create 50 progressive frames. They don't use 1080p/50/60 as it would be far too bandwidth hungry for transmission.
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#71 |
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No, it's filmed at 1080i50 - 25fps - but 1080P25 wouldn't look any different, exact same frame rate on the screen.
1080i and 1080p both deliver 25 full frames per second, however 1080i delivers 50 fields. 1080p only delivers 25 fields. In other words: 1080p25 gives 25 updates to the picture each second - 25 full frames. 1080i50 gives 50 updates to the picture each second - but still only 25 full frames. Compare a Hollywood movie versus Coronation Street. One is shot at 24p (upped to 25fps for PAL broadcast), the other at 50i. Both will look very different. |
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#72 |
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It would look different, it would look very different.
1080i and 1080p both deliver 25 full frames per second, however 1080i delivers 50 fields. 1080p only delivers 25 fields. In other words: 1080p25 gives 25 updates to the picture each second - 25 full frames. 1080i50 gives 50 updates to the picture each second - but still only 25 full frames. Compare a Hollywood movie versus Coronation Street. One is shot at 24p (upped to 25fps for PAL broadcast), the other at 50i. Both will look very different. |
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#73 |
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I can't understand the confusion here, 1080i only uddpates half the picture data every 1/50 sec. The other half comes from the next field. 1080p25 delivers the same data but without any time difference (at the same time as the video data from the previous 1/50th of a second.
Both give 25 full frames per second, but 1080i gives 50 fields per second. Interlaced gives you twice the number of updates, but it only updates half of the frame each time. |
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#74 |
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Where is the confusion?
Both give 25 full frames per second, but 1080i gives 50 fields per second. Interlaced gives you twice the number of updates, but it only updates half of the frame each time. |
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#75 |
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It would look different, it would look very different.
1080i and 1080p both deliver 25 full frames per second, however 1080i delivers 50 fields. 1080p only delivers 25 fields. In other words: 1080p25 gives 25 updates to the picture each second - 25 full frames. 1080i50 gives 50 updates to the picture each second - but still only 25 full frames. De-interlacing in the set means you ONLY get 25 updates per second, exactly as with P25 - unless you have a 100/200Hz set which interpolates extra frames in between. |
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I am not positive as to what my plasma (non frame interpolating) is doing with the deinterlacing.