SageTV HD Media Extender

[CollinR]

1080i is about half the resolution of 1080p, all scaling is bad. We may spend decades tring to deinterlace 1080p, may never happen.

[autoboy]

By scaling I mean everything included in scaling. I was using it as a general term for making content fit my TV. My TV (Sony KDS60A3000) actually has a very good scaler but cannot do proper 1080i.

I never really considered outputting everything at 1080i because before I considered the Reon, I always avoided interlacing the picture at all costs. That might just work! Hmm. Lets think about it...

If I am watching a video source at 480i like most TV, then the picture is deinterlaced by the extender to 480p, then scaled to 1080i. Then the reon has to deinterlace the video content and it does a motion adaptive deinterlace on the video content to get 1080p, losing quality in the deinterlace right? For film material, the HD extender deinterlaces the 480i content to 480p but doesn't do inverse telecine to get the original progressive frames, then it gets scaled to 1080i and the reon tries to put the film material back together using the inverse telecine process, but it can't because that film material is all messed up from the improper scale to 480p instead of the proper inverse telecine on the 480i to 480p, so you lose quality again. hmm, I might be totally wrong here but that doesn't sound like a great solution because you still can't pull out 480p/24 out of the film content and perform the correct 3:2 pulldown. You still end up doing double scaling with quality loss and I would rather just have the HD extender output the 1080p and do it's own scaling. The Reon may be good, but it can't be magic. I think just to be safe I will only use the Reon if I can get the native output. I guess I will just have to wait and see. I've been waiting forever though. I just want to buy one already!!!!!!

[autoboy]

Originally Posted by CollinR

1080i is about half the resolution of 1080p, all scaling is bad. We may spend decades tring to deinterlace 1080p, may never happen.

This is not true. The ReonVX in the Toshiba xa1 and onkyo 875 are able to pull out the full 1080p/24 picture from a 1080i/60 film source, and can do vector adaptive deinterlacing that takes 4 frames into account to get the best possible resolution out of 1080i/60 video content. 1080i can be very good quality now with the right eqipment. Also, set up properly, a 7600GT/8600GTand x1600pro/2600pro and above can do almost as well as the ReonVX.

[CollinR]

Originally Posted by autoboy

By scaling I mean everything included in scaling. I was using it as a general term for making content fit my TV. My TV (Sony KDS60A3000) actually has a very good scaler but cannot do proper 1080i.

You have a full 1080p display, 1080i doesn't look so hot cause it's interlaced.

I bet SDTV full screen really looks bad on that thing!

Originally Posted by autoboy

I never really considered outputting everything at 1080i because before I considered the Reon, I always avoided interlacing the picture at all costs. That might just work! Hmm. Lets think about it...

It doesn't much matter what you do, except for running the video in a window. You should probably be using a PC based client on that display, this way you can surround the video window with other stuff and take full advantage of that display.

Originally Posted by autoboy

If I am watching a video source at 480i like most TV, then the picture is deinterlaced by the extender to 480p, then scaled to 1080i. Then the reon has to deinterlace the video content and it does a motion adaptive deinterlace on the video content to get 1080p, losing quality in the deinterlace right? For film material, the HD extender deinterlaces the 480i content to 480p but doesn't do inverse telecine to get the original progressive frames, then it gets scaled to 1080i and the reon tries to put the film material back together using the inverse telecine process, but it can't because that film material is all messed up from the improper scale to 480p instead of the proper inverse telecine on the 480i to 480p, so you lose quality again. hmm, I might be totally wrong here but that doesn't sound like a great solution because you still can't pull out 480p/24 out of the film content and perform the correct 3:2 pulldown. You still end up doing double scaling with quality loss and I would rather just have the HD extender output the 1080p and do it's own scaling. The Reon may be good, but it can't be magic. I think just to be safe I will only use the Reon if I can get the native output. I guess I will just have to wait and see. I've been waiting forever though. I just want to buy one already!!!!!!

Actually the picture is interlaced by the extender, before going out as an NTSC feed through the composite or S-Video ports. It was deinterlaced by the encoder and encoding processes while put on disk. So 480i being scaled to 1080p by the TV. Not suprising it doesn't look real good, what you see on the screen is like 75% made up in scaling and 25% content. As I mentioned before you would be better off running in a window 25% the size of the display.

You loose quality when you interlace not when you deinterlace... Interlacing was done to reduce the amount of bandwidth needed for TV back in the 30s we have stuck with it so long for who know why but we have. It's called NTSC and everything that connects universally with composite video adheres to it.

[CollinR]

Originally Posted by autoboy

This is not true. The ReonVX in the Toshiba xa1 and onkyo 875 are able to pull out the full 1080p/24 picture from a 1080i/60 film source, and can do vector adaptive deinterlacing that takes 4 frames into account to get the best possible resolution out of 1080i/60 video content. 1080i can be very good quality now with the right eqipment. Also, set up properly, a 7600GT/8600GTand x1600pro/2600pro and above can do almost as well as the ReonVX.

That sounds alot like marketing hype to me, and how would you prove them wrong? It's not like you can oscilloscope these things anymore.

[bialio]

Originally Posted by CollinR

You have a full 1080p display, 1080i doesn't look so hot cause it's interlaced.

I don't think that's at all the case - most people seem to report that 1080i source that is properly deinterlaced is indistinguishable from 1080p.

1080i isn't half the resolution of 1080p. They are both 1920x1080. Just how that info is conveyed is different.

[bialio]

Originally Posted by CollinR

1080i is about half the resolution of 1080p, all scaling is bad. We may spend decades tring to deinterlace 1080p, may never happen.

To de-interlace 1080p requires the RVTC algorithm - reverse telecaster. Uses an electric guitar tuned backwards to extrapolate each frame. It's very expensive to implement, mainly due to the eccentricities of musicians.

btl.

[autoboy]

Umm, Collin, I don't think you understand interlaced content very well. Nothing I said is marketing hype, but can be proven with non subjective video quality tests like the HQV test disk, and other DVDs and HD-DVD that prove troublesome on average equipment. I don't belive in marketing hype, I am stating facts.

You have a full 1080p display, 1080i doesn't look so hot cause it's interlaced

Yes, my TV is a progressive scan TV with 1920x1080 resolution. In order to display an interlaced signal, my TV or other equipment must deinterlace this to a progressive frame. There are many ways to do this, and some of them are better than others, with some of them able to display the full 1080p resolution from a 1080i signal using a process called Inverse Telecine. This is the process that my TV and the HD extender will not be able to do, and is why I am considering the video processor in the Onkyo receiver.

It doesn't much matter what you do, except for running the video in a window. You should probably be using a PC based client on that display, this way you can surround the video window with other stuff and take full advantage of that display.

This makes no sense at all. 1080i uses the same resolution as 1080p, but every frame is only half of the content. The video processor puts them together to get the full 1080p that my TV displays. Since 1080i is the same size as 1080p, there is no windowing possible on my display unless I actually scalled the video down on my computer. if I played 720p on my display and wanted a 1:1 picture, then yes, there would be some extra room on my display, but doing a good 720p -> 1080p scale is actually pretty freaking easy now and looks great on my TV. It is only slightly less sharp than 1080p native content.

Actually the picture is interlaced by the extender, before going out as an NTSC feed through the composite or S-Video ports. It was deinterlaced by the encoder and encoding processes while put on disk. So 480i being scaled to 1080p by the TV. Not suprising it doesn't look real good, what you see on the screen is like 75% made up in scaling and 25% content. As I mentioned before you would be better off running in a window 25% the size of the display.

When did I say I was using composite or SVideo?

I bet SDTV full screen really looks bad on that thing!

Yeah, it looks pretty bad but it is freaking HUGE! SD is SD. It sucks comparted to HD, but a good processor can make things better. It would look just as bad on a 60" SD TV too! I'm not expecting a miracle. I just want good 1080i deinterlacing. Hopefully I won't be watching 480i TV much more, but first, Comcast has to stop sucking with their HD programming. ON Demand does not count!

[CollinR]

Discussing or arguing over the deinterlacing abilities of a device that is not yet known is foolish. I'll prefer to wait and see one, then deside.

[stanger89]

Originally Posted by CollinR

1080i is about half the resolution of 1080p, all scaling is bad. We may spend decades tring to deinterlace 1080p, may never happen.

You need to be careful to specify which i/p you're talking about. 1080i and 1080p (regardless of framerate) have the same number of vertical lines of resolution, 1080. Where you run into one being inferior to the other is when you have to drop fields, ie going from 1080p60 to 1080i60, you drop one field each refresh. However this doesn't occur in the real world because there is no 1080p60 content, everything is 1080p24 (movies) or 1080i60 (video). 1080p24 or even 1080p30 can be stored/transmitted "losslessly" in 1080i60.



As for deinterlacing 1080i, Silicon Optics and Gennum both have solutions that are more than capable of deinterlacing 1080i properly, as do nVidia and ATI.

Originally Posted by autoboy

By scaling I mean everything included in scaling. I was using it as a general term for making content fit my TV. My TV (Sony KDS60A3000) actually has a very good scaler but cannot do proper 1080i.

Deinterlacing and scaling are really two completely separate things, except that scaling depends on deinterlacing happening first.

I never really considered outputting everything at 1080i because before I considered the Reon, I always avoided interlacing the picture at all costs. That might just work! Hmm. Lets think about it...



If I am watching a video source at 480i like most TV, then the picture is deinterlaced by the extender to 480p, then scaled to 1080i.

Technically it's probably scaled to 1080p and then interlaced.

Then the reon has to deinterlace the video content and it does a motion adaptive deinterlace on the video content to get 1080p, losing quality in the deinterlace right?

That's probably debateable, the result of the deinterlacing of 480i will be 480p24 or 480p30. This will be scaled to 1080p24 (or 30), and will be interlaced. At this point it's "progressive sourced" meaning each even/odd field pair is from the same image, so the Reon should recognize that it doesn't need to do any further processing beyond a weave.



Or, to look at it another way, the "damage" is already done when the 480i is deinterlaced.

For film material, the HD extender deinterlaces the 480i content to 480p but doesn't do inverse telecine to get the original progressive frames, then it gets scaled to 1080i and the reon tries to put the film material back together using the inverse telecine process, but it can't because that film material is all messed up from the improper scale to 480p instead of the proper inverse telecine on the 480i to 480p, so you lose quality again.

It's kind of hard to tell what happens here. The extender has access to all the MPEG flagging info, so for well coded stuff, it should be able to properly reconstruct the progressive frames. If you look around you'll see that even cheap devices can generally handle well mastered content correctly these days.



For example, take a look at the Toshiba HD DVD players, no Reon processor (not the original ones) and yet they were very highly regarded in their upscaling capabilities.

hmm, I might be totally wrong here but that doesn't sound like a great solution because you still can't pull out 480p/24 out of the film content and perform the correct 3:2 pulldown. You still end up doing double scaling with quality loss and I would rather just have the HD extender output the 1080p and do it's own scaling.

Well the point of outputting 1080i vs 1080p is that it's not the SD stuff that you need to worry about, it's the HD stuff. I'd probably trust a Sigma chip to handle SD well, but if I had a Reon or Gennum, I'd want that handling my 1080i.

The Reon may be good, but it can't be magic. I think just to be safe I will only use the Reon if I can get the native output. I guess I will just have to wait and see. I've been waiting forever though. I just want to buy one already!!!!!!

Like I said, SD is easy, even cheapo stuff can handle that well, and you're not going to lose anything outputting deinterlaced content at 1080i60 vs 1080p60, where you are going to have a difference is deinterlacing 1080i in a cheap processor vs a good one.

[mikejaner]

1080P is 24 or 30 FPS. 1080i is 60FPS, so the arguement that it is the same amount of information is true, but misleading. This is because it depends on the origin of the content. If it was filmed, and transferred digitally to a 1080P source, or even recorded in 1080p camera that supports that resolution, then you might have an arguement about reconstructing the frames in a deinterlace routine. I bet you would still a lose a little data in the conversion to 1080i though.

If the content was recorded, like some networks do, in 1080i at the camera, then you will see a difference. Take into account when deinterlacing two 540 line frames. The way it's filmed is at 1080i, which are 1/60th of a second apart, and splicing them together. When you do this you get a 1080 line frame, with slight motion artifacts from the motion which happens in that time. Obviously this is more noticeable in fast motion scenes.

Either way, the content looks better than SDTV, and that's all I really care about. I watched Transformers in HD this weekend on my 103" screen with my 720p projector, and it looked great!!

To change the subject, when are we gonna get the announcement about the extender?!?!? I know it's coming out in the middle of Nov, but that doesn't mean we can't get the jucy details beforehand.

[stanger89]

Originally Posted by mikejaner

1080P is 24 or 30 FPS. 1080i is 60FPS, so the arguement that it is the same amount of information is true, but misleading. This is because it depends on the origin of the content. If it was filmed, and transferred digitally to a 1080P source, or even recorded in 1080p camera that supports that resolution, then you might have an arguement about reconstructing the frames in a deinterlace routine. I bet you would still a lose a little data in the conversion to 1080i though.

Movies are shot on film these days, still almost exclusively, they are then scanned at either 2k or 4k to create the DI. The content is then (at the final stage) converted to 1080p24 where it is either stored on disc with the appropriate flags to allow the player to telecine it, or it's telecined into 1080i60 for broadcast.

Regardless of that, 1080i can transmit all content (available today, ie 1080p24, 1080p30, 1080i60) 'losslessly'.

If the content was recorded, like some networks do, in 1080i at the camera, then you will see a difference. Take into account when deinterlacing two 540 line frames. The way it's filmed is at 1080i, which are 1/60th of a second apart, and splicing them together. When you do this you get a 1080 line frame, with slight motion artifacts from the motion which happens in that time. Obviously this is more noticeable in fast motion scenes.

If it's 1080i, you lose nothing by transmitting at 1080i. What you're actually talking about are the deinterlacing issues that affect non-1080i displays. Which is a different (though not unconnected) issue.

[tmiranda]

My guess is that 99.14% of the people who look at HDTV can't tell the difference in the picture regardless of all the techie-speak. All they know (and care about) is that HDTV looks a lot better than SDTV.

[mikejaner]

f it's 1080i, you lose nothing by transmitting at 1080i. What you're actually talking about are the deinterlacing issues that affect non-1080p displays. Which is a different (though not unconnected) issue.

From what I understand, you meant to say this affect is related to progressive display's, not non-progressive displays. But I want to argue this (lightheartedly of course) a little more.

[When talking about a 1080i origin based source to a 1080p display]
From what I have seen, when an interlaced image is deinterlaced, during a fast motion scene, to a progressive image/progressive display, you will see a stepping affect between the two lines being interleaved. This, to me, is because there is change in movement for that 1/60th of a second where the camera was capturing the second of the two interleaved frames.

[When talking about 1080p/24 or 1080p/30 source]
I agree that the reconstruction doesn't cause this issue, and it is 'lossless' with ' ' being stressed.

[Stuntman]

Note to Sage.. It is Christmas buying season and I fully intend to do all my shopping in the next couple of weeks.. what with shipping and wrapping and all, you have to give us some time!! I'd really like to get a couple of these HD Extenders and Christmas is the time I'd be buying.. makes it easier to justify! If the timing of the release brings it too close to Christmas, I'll have to pass on it until some future date.

Just a thought.. and a nudge..

[Motofreak75]

all I got to say is as long as the picture looks good and play most the popular formats that the public wants, then bring on Sage 6.5 with the SZ1350 extender





please do not take my post seriously

[mayamaniac]

As far as I know, all broadcast signals are interlaced, whether it's HD or SD. HD is at 1920x1080 interlaced at 29.97fps square pixel. SD is at 720x480 interlaced at 29.97fps non-square/D1 (0.9) pixel. This is the standard broadcast format, regardless of the source, which maybe 24fps or 30fps depending on where it comes from.

So where do you get content that's 1080p/30 or 1080p/60? Are the contents on Blu-ray/HD-DVD really 1080p or are they 1080i and the hardware on the player is deinterlacing it to 1080p?

[stanger89]

Originally Posted by mikejaner

From what I understand, you meant to say this affect is related to progressive display's, not non-progressive displays. But I want to argue this (lightheartedly of course) a little more.

Yeah, sorry, I meant non-1080i displays.

[When talking about a 1080i origin based source to a 1080p display]
From what I have seen, when an interlaced image is deinterlaced, during a fast motion scene, to a progressive image/progressive display, you will see a stepping affect between the two lines being interleaved. This, to me, is because there is change in movement for that 1/60th of a second where the camera was capturing the second of the two interleaved frames.

There are two ways to deal with deinterlacing, you can either combine fields together (weave), which retains the spacial resolution of the image, but loses half the temporal resolution, or you can display each field separately and process the image to create the correct height (bob), this retains the temporal resolution but sacrifices spacial resolution.

For film (progressive) sourced content, it's easy, you do the former (combine fields) and the result is full spacial resolution since each even/odd field pair is from the same image.

For video content, the problem is much more difficult, as the nature of the content changes from one moment to the next. Each field (even/odd) is from a unique moment in time, they're from a different image. One moment the entire picture is roughly static and essentially progressive, it would be a shame to bob this and lose half the spacial resolution when there's no temporal resolution to be gained loss. Contrast that with a quick pan, and not only would weaving lose half the temporal resolution, but it would introduce combing from combining two different images into one.

This is why many early 1080i deinterlacers simply bobbed everything, it's much easier.

Today, we have processors like the Gennum VXP and Realta HQV, which perform motion adaptive deinterlacing of 1080i video, and IVTC of 1080i film.

What happens with motion adaptive DI is the processor looks a small pieces of the image over a period of frames and determines if there is motion or not, and uses that to decide if it should bob or weave that section of the image. It does this dynamically over the image, thus maintaining the best of both worlds, spacial and temporal resolution.

You mention stepping, that comes from bobbing with a "simple" algorithm. The simplest being simply doubling each line, which causes the dreaded "jaggies". But starting with Faroudja's DCDi for SD, and continuing/expanding other products and now to 1080 in the form of Gennum VXP, Realta HQV and even the latest nVidia/ATI hardware, bob deinterlacing is not done by simply doubling lines, it goes through sophisticated algorithms to properly scale the image to reduce or even eliminate jaggies.

It's this handling of video-sourced 1080i that is very processor intensive and something I don't expect a low-cost CE chip to do well, not yet at least (contrast that with SD, where good deinterlacing is common in CE solutions). This is why my fallback recommendation was to output 1080i and let a good processor (VXP, HQV, Reon, etc) handle 1080i content. Odds are the processor in the extender (likely a Sigma chip) can do a competent job with SD, but probably just bobs all 1080i when it needs to process that.

[geogecko]

They broadcast HD in 720p, don't they? At least, that's what Sage tells me it is. I've only seen 1080i so far, on broadcast TV though, no 1080p.

[stanger89]

Originally Posted by mayamaniac

As far as I know, all broadcast signals are interlaced, whether it's HD or SD. HD is at 1920x1080 interlaced at 29.97fps square pixel. SD is at 720x480 interlaced at 29.97fps non-square/D1 (0.9) pixel. This is the standard broadcast format, regardless of the source, which maybe 24fps or 30fps depending on where it comes from.

Almost correct, there is one more "standard" broadcast format, 720p60, used by Fox, ESPN, maybe ABC (I could be confusing these).

So where do you get content that's 1080p/30 or 1080p/60? Are the contents on Blu-ray/HD-DVD really 1080p or are they 1080i and the hardware on the player is deinterlacing it to 1080p?

Well there is no 1080p60 content, 1080p60 isn't defined as a valid format anywhere but in interconnections between devices. Most content on HD DVD/BD is 1080p24 and the player will telecine it to 1080i60 for most displays. Early players (maybe even current ones) would IVTC the 1080i60 back to 1080p24 (and repeat frames to 1080p60) if you have progressive output selected. But the content on the disc is 1080p24. I think 1080p30 is supported on HD DVD and BD, but it's largely theoretical as most all content falls into either 24p (film) or 60i (video) or 60p (720 only though) video.

It's theoretically possible for an HD DVD or BD player to output the native 1080p24, but I haven't kept up with the standalones enough to know if any actually do (I think the PS3 might).