Re: [Deinterlace-discuss] Is a non-linear stretch mode planned?
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Re: [Deinterlace-discuss] Is a non-linear stretch mode planned?
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From: Mark R. <ma...@ot...> - 2001-01-10 21:44:15
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Hi, Basically, it would be some kind of an algorithm that does the pre-distort on a scanline basis (panorama) before sending to the video overlay hardware to do the scaling. The video overlay hardware will actually continue to do the scaling, of course. Should be doable. Might need a faster CPU, but fast-enough CPU exists nowadays to do stuff like this, I believe. It would be a huge challenge to get the CPU requirement low enough though. I give my vote for this panorama feature!! Michael Eskin wrote: > > I don't think this is going to fit in with how dTV does its scaling, since > it uses the overlay scaling capability of the graphics controller to > accomplish its display, and as far as I know, all graphics adapters pretty > much just implement linear scaling on their overlay surfaces. > > Of course, I'd love to be proven wrong here... I can't see the host > processor doing the scaling, maybe on a P4? > > Cheers, > > Michael Eskin > Conexant Systems > > ----- Original Message ----- > From: "Paul Simoneau" <psi...@in...> > To: <dei...@li...> > Sent: Wednesday, January 10, 2001 6:45 AM > Subject: RE: [Deinterlace-discuss] Is a non-linear stretch mode planned? > > I'll agree that there are cases when the APAC feature isn't used. > It's disabled when using high-bandwidth inputs, so if we could get > dTV to implement something to fill out the entire raster, I think > that would be a welcome feature. > > As far as the Panorama mode, I believe it's semi-hyperbolic at the > edges, but remains pretty linear in the middle section of the screen. > If you're watching a TV channel that's got a stock ticker at the bottom > of the screen, you should be able to see large amounts of stretching > going on at the edges, but once you get to the middle, very little > is done to the image. > > I think some sort of balancing act between two main requirements would be : > 1) leave as much of the original image unaltered as possible > 2) that which you do have to touch, tread lightly > > Sure, it'd be great to fill the whole screen, but I'd rather avoid > having a distracting "circus mirror" (due to too much stretching) > or "banding" (poor image interpolation) effects on the image. The > Philips does a pretty good job, and as I said before, I watch all > my 4:3 sourced material in that mode. > > Once again, how much processing this would take is a major concern, also. > > We currently render a 480 pixel image height for the image. To > form a 16:9 version of this, we're in the neighborhood of 853x480. > So, given our 720-pixel width, we need to "create" ~130 pixels more > than the original 720 pixels to fill out that 16:9 frame. > > > -----Original Message----- > > From: dei...@li... > > [mailto:dei...@li...]On Behalf Of > > Eric Schmidt > > Sent: Tuesday, January 09, 2001 6:37 PM > > To: dei...@li... > > Subject: RE: [Deinterlace-discuss] Is a non-linear stretch mode planned? > > > > > > This panaramic stretch feature has actually been on my private list of > > features I'd like to see in the future. I am unfamiliar with any of the > > real "guts" of the dTV program so I don't know what size job it would be. > > > > I would guess that it's a hyperbolic transformation in x where as > > the normal > > anomorphic stretch is linear. I don't have any evidence to support this, > > just a feeling. If I were to take on the challenge, I'd be sure > > to do some > > measurements with a grid input signal first. But I do not believe it's > > simply a matter of stretching the edges and leaving the center unchanged. > > > > Also, the APAC feature on the 64PH9905 only kicks in when watching 4:3 > > signal through either the set's Composite or COAX video inputs. > > Not through > > the YPrPb or VGA inputs which I would guess those of us who have this set > > are using with our HTPCs. Just mentioning this to support the need for > > orbiting in dTV. > > > > -Eric > > > > | -----Original Message----- > > | From: dei...@li... > > | [mailto:dei...@li...]On Behalf Of > > | Paul Simoneau > > | Sent: Monday, January 08, 2001 6:39 PM > > | To: dei...@li... > > | Subject: RE: [Deinterlace-discuss] Is a non-linear stretch mode planned? > > | > > | > > | > > | To add to the point : > > | > > | I have a very similar HDTV model, the Philips 55PP9701, with the only > > | differences being the size and the lack of an integrated ATSC tuner. > > | So, I can expand a little bit on what Steve proposes. > > | > > | The Philips models offer a few of the "standard" widescreen "stretch" > > | modes, and like many other manufacturer's sets, the only operate in the > > | interlaced mode. Once a progressive or HDTV input is selected, you're > > | stuck in HDTV/progressive-squeeze mode. No aspect ratio manipulation. > > | So, this isn't a problem unique to Philips, but to most HDTV sets. > > | > > | 1. Standard 4:3 mode : 4:3 frame with black bars on the sides > > of the image > > | 2. 16x9 mode : do the anamorphic squeeze > > | 3. Theater-1 : zoom in on a 4:3 image which contains a 1.85:1 letterbox > > | 4. Theater-2 : zoom in MORE on a 4:3 image which contains a > > | 2.35:1 letterbox > > | 5. Panoramic : approximately the middle 1/2 of the 4:3 image is left > > | intact, while the outer 1/4's of the image on either side > > | are "streeeetched" to fill the rest of the raster and > > | prevent the need for any bars. The further towards the > > | edge you go, the more stretch is introduced. > > | > > | I view all 4:3 source material in the Panorama mode. The stretching > > | on the sides isn't too objectionable, and you don't lose any of the > > | original source frame (as you do in the Theater-X modes). > > | > > | (BTW, the Philips already incorporate an "orbit" feature. > > | Automatic Phosphor Aging Compensation - APAC.) > > | > > | > > | I think this would be a big win for all widescreen users of dTV. > > | > > | However, given that there would have to be a field-by-field > > | manipulation in order to do some kind of stretch function on > > | the source data, how much additional CPU horsepower would this > > | require ? Quite a bit, I might imagine. > > | > > | Would be nice, though... > > | > > | > > | Paul Simoneau > > | Integral Access, Inc. > > | psi...@in... > > | > > | > > | > > | > > | > -----Original Message----- > > | > From: dei...@li... > > | > [mailto:dei...@li...]On Behalf Of > > | > Daniel Schmelzer > > | > Sent: Monday, January 08, 2001 10:34 PM > > | > To: dei...@li... > > | > Subject: [Deinterlace-discuss] Is a non-linear stretch mode planned? > > | > > > | > > > | > Hi All-- > > | > > > | > Interesting requests from SteveT on AVS Forum at: > > | > > > | > http://www.avsforum.com/ubb/Forum12/HTML/006836.html > > | > > > | > "First, let me say thanks to all the dTV developers for making > > | > this awesome > > | > piece of software available. This work of art the rivals (and in > > | > many ways > > | > is better than) the Genesis de-interlacer in my Philips 64PH9905 HD > > | > RPTV--particularly with dss and video game sources. > > | > > > | > I have a question however, regarding the "stretch" mode. Since > > | > the majority > > | > of dss programming is in 4:3 AR, I have gotten quite used to using the > > | > 9905's "Panoramic" video mode. This mode stretches the edges of > > | the image > > | > but leaves the center untouched. The result of this non-linear > > | > stretch is a > > | > good alternative to viewing 4:3 material on a 16:9 screen. > > And while not > > | > perfect, it is far less distracting than a linear stretch where > > | > the entire > > | > image is stretched horizontally. I believe the type of viewing mode is > > | > standard on most, if not all HD and HD Ready sets. IMHO, it would be a > > | > wonderful addition to dTV's feature set. > > | > > > | > On a similar topic, are there any plans to incorporate any > > form of image > > | > "orbiting" (a la yXy) to reduce image burn-in when watching > > | > letterboxed or > > | > side-paneled material? > > | > > > | > Thanks again for the wonderful work! > > | > > > | > Regards -- Steve" > > | > _________________________________________________________________ > > | > Get your FREE download of MSN Explorer at http://explorer.msn.com > > | > > > | > > > | > _______________________________________________ > > | > Deinterlace-discuss mailing list > > | > Dei...@li... > > | > http://lists.sourceforge.net/mailman/listinfo/deinterlace-discuss > > | > > > | > > | > > | > > > > > > _______________________________________________ > > Deinterlace-discuss mailing list > > Dei...@li... > > http://lists.sourceforge.net/mailman/listinfo/deinterlace-discuss > > > > _______________________________________________ > Deinterlace-discuss mailing list > Dei...@li... > http://lists.sourceforge.net/mailman/listinfo/deinterlace-discuss > > _______________________________________________ > Deinterlace-discuss mailing list > Dei...@li... > http://lists.sourceforge.net/mailman/listinfo/deinterlace-discuss -- _______________________________________________________________________ ____ Mark D. Rejhon Win2k.Linux.Win98 \ / mailto:ma...@ot... http://www.marky.com/ C.C++.VB.Shell \/ AlphaWorld Home 10S 15W "A friend is someone who will be there without asking anything of you. A friend is someone you know that knows you, and accepts you." _______________________________________________________________________ |
