Some Video Processors, Blu-Ray players and HD-DVD players can convert standard DVD's and 1080/60i HDTV material to 1080/24p. Lumagen processors, the higher end Toshiba HD-DVD players and some Panasonic BD players do this.

Reading a brochure describing the JVC DLA-RS15 it seems to indicate that the projector can do this as well. (see below). Does this happen automatically? If you are watching a movie on HBO-HD in 1080/60i, will the projector automatically display it using frame rate conversion at a multiple of 24hz or do you have to set a certain mode to get it to do this?

Is there no need for a frame rate converting source device, like a lumagen processor or one of the more exotic BD or HD-DVD players? Will the projector always just display film sourced 1080i and 480i material at even multiples of 24hz?

(From JVC Brochure) - Inverse telecine (reverse 2-3 pulldown) -To display TV broadcasts or commercially available DVDs created using the 2-3 pulldown process, the inverse telecine function re-converts the video source back to a 24fps signal and displays it at double speed or 48 fps, ensuring cinema-like viewing faithful to the original source.

Some Video Processors, Blu-Ray players and HD-DVD players can convert standard DVD's and 1080/60i HDTV material to 1080/24p. Lumagen processors, the higher end Toshiba HD-DVD players and some Panasonic BD players do this.

Reading a brochure describing the JVC DLA-RS15 it seems to indicate that the projector can do this as well. (see below). Does this happen automatically? If you are watching a movie on HBO-HD in 1080/60i, will the projector automatically display it using frame rate conversion at a multiple of 24hz or do you have to set a certain mode to get it to do this?

Is there no need for a frame rate converting source device, like a lumagen processor or one of the more exotic BD or HD-DVD players? Will the projector always just display film sourced 1080i and 480i material at even multiples of 24hz?

(From JVC Brochure) - Inverse telecine (reverse 2-3 pulldown) -To display TV broadcasts or commercially available DVDs created using the 2-3 pulldown process, the inverse telecine function re-converts the video source back to a 24fps signal and displays it at double speed or 48 fps, ensuring cinema-like viewing faithful to the original source.

Inverse Telecine is not a new feature with this year's models. It's been around for awhile. It is the "Film Mode" option and even my ancient SP7205 has it with the venerable Faroudja chip. I don't know why they've hyped it up in this year's brochure.

The only thing that might be different is in previous models I think there was only an Auto/Off setting whereas in the RS25 manual I looked at there is another choice Auto/Film/Off in order to force Film mode and not rely on cadence detection to start Film mode. Perhaps it's like this with the RS10/20, but I never took a look at those manuals.

i looked at a RS20 manual and it was like the RS2 w/ Auto/Off so it looks like the dedicated Film mode that the marketing gurus are hyping.

Inverse Telecine, as described in the brochure for the RS15, is not the inverse telecine you are describing on your SP7205, but rather a FRAME RATE CONVERSION from 1080/60i or 480/60i to 1080/48. Basically frame doubling 1080/24p.

So although inverse telecine is not new, the frame rate conversion that the RS15 brochure claims is something novel and only found on some video processors, BluRay players and HD-DVD players.

Your Sp7205 does not do this, it merely does 60hz 3-2 cadence display. Not a true frame rate conversion to 24p then displaying the frames at 48hz as the JVC brochure describes.

My question is, is the brochure wrong. It may be that the brochure is bogus and that the JVC RS15/25 do NOT do this sort of frame rate conversion.

Inverse Telecine, as described in the brochure for the RS15, is not the inverse telecine you are describing on your SP7205, but rather a FRAME RATE CONVERSION from 1080/60i or 480/60i to 1080/48. Basically frame doubling 1080/24p.

So although inverse telecine is not new, the frame rate conversion that the RS15 brochure claims is something novel and only found on some video processors, BluRay players and HD-DVD players.

Your Sp7205 does not do this, it merely does 60hz 3-2 cadence display. Not a true frame rate conversion to 24p then displaying the frames at 48hz as the JVC brochure describes.

My question is, is the brochure wrong. It may be that the brochure is bogus and that the JVC RS15/25 do NOT do this sort of frame rate conversion.

Inverse telecine really refers to recreating a 24p ( nominally 23.976) sequence from suitably mastered 60i (nominally 59.94). The actual playback rate is a seperate issue.

My understanding is that the JVCs double this to 48p and then display back at 96Hz: essentially doubling again. The latest frame interpolation modes obviously work a little differently (creating inbetween frames from the 24p rather than repeating real ones to smooth out motion presentation)

With 60Hz native displays that also do inverse telecine usually what happens is that the 60i gets deinterlaced to 24p and then regular whole frame repeats are added to get the display rate back up to 60p. So it is a true inverse telecine but with frame repeats to cater for the non-multiple display rate.

Inverse telecine (60i to 24p) is actually quite an easy process , the cadence is very easy to detect given suitably mastered material. Obviously with a display that refreshes at direct multiples of 24 you get smoother presentation than a display that is stuck with 60Hz: however some people are more sensitive to this than others.

No other projector I know of takes film sourced 480i material and displays it at an even multiple of 24hz. Last years JVC's, the RS10 and RS20, did not do this. Right now I use a Toshiba HD-35 HD-DVD player to playback 480i DVD's since it will convert them to 24p, and I have a lumagen video processor that does this for 1080/60i HDTV material. I guess I am sensitive to the 3-2 "judder" created when film sourced material is converted to 60hz, the way all other projectors do it. So to me this was quite a nice surprise when I read about it.

I admit its been a while since I ran 480i or 1080i at 60Hz into my HD1 so I'm not prepared to categorically state that the JVCs take 60i inverse telecine it and display at 24 multiples.

However I can find a fair bit of info on the net that seems to suggest it does and certainly I don't remember having any problems with it that made me think it was refreshing at multiples of 60 with this material.

No other projector I know of takes film sourced 480i material and displays it at an even multiple of 24hz....

I assume you are talking about 24fps films encoded onto DVDs at 480i/60. I am currently using a Samsung BD2500 that up converts DVD films to 1080p/60 with 3:2 pulldown. It is connected to a Sanyo Z3000 projector which can detect this type input, converting it to 120hz 5:5 cadence (an equal multiple of 24hz) I believe this is a common feature on many projectors in this price range ($2k+)

Dan

Talk about marketing BS. The new JVC ad on the back of October`s WSR. It plugs the JVC`s as the ULTIMATE in quality. And describes the I assume PQ as FLAWLESS, BRILLIANT,and STUNNING. As good as the very fine JVC`s are, they are certainly not the ultimate in anything but native on\off CR and the PQ is still flawed in several area just like other projectors exhibit PQ flaws.

Talk about marketing BS. The new JVC ad on the back of October`s WSR. It plugs the JVC`s as the ULTIMATE in quality. And describes the I assume PQ as FLAWLESS, BRILLIANT,and STUNNING. As good as the very fine JVC`s are, they are certainly not the ultimate in anything but native on\off CR and the PQ is still flawed in several area just like other projectors exhibit PQ flaws.

Those terrible ad writers!
I would fire them!

JVC RS15
FLAWED, BLURRY, OVERSATURATED...

Would that be better? ;)

By coincidence, Inverse telecine is something that I've been working on a lot lately. I think there are two concepts that are getting confused in this thread. Inverse telecine derived from 60i NTSC sources has been around for a long time and involves removing the redundant fields in the 2:3 NTSC pulldown sequence and adding a repeat field. The result in a MPEG transport stream is still interlaced but it can be reconstructed to yield 24p on the decoder end (but standard 60i can also yield 24p). The original reason for using inverse telecine was to save the 20% space that the repeated fields consume. In actual practice inverse telecine is troubleprone and something that both encoders and decoders struggle with and there are a lot of incompatibilties (especially getting the playout framerate to work properly). Poynton also mentions that it's complex and trouble-prone.

1080p24 on the other hand is a standard SMPTE format (274M IIRC) that is truly progressive with only one field per frame. Taking 1080i60 and converting it to true 1080p24 is what I assume JVC means by inverse telecine and I think this adds confusion by those who have always thought of this as the process of removing redundant fields and adding a repeat flag.

Getting back to the OP's point of whether the final 1080p24 format on the JVC will be any better than what people are getting out of a video processor - Most HQV and VXP solutions that I've used seem to be quick to switch to other cadences which can be a good thing sometimes but also can give "false positives" and cause the playback to stutter for a few seconds. Stuttering 1080p24 looks terrible and much worse than the micro judder from the original 3:2 NTSC cadence. The better processors usually have an overide mode to force 3:2 cadence which helps during a movie to get rid of the occasional studder. A simple film mode setting may not be enough. The DVDO VP50 Pro is a good example of a processor that has an auto mode, film mode and force 3:2 mode and for watching movies the "force 3:2" mode works really well (better than the built-in VXP and HQV solutions I've used in most display devices). If the JVC doesn't have such a mode then it may studder more than a VP would, otherwise I would expect it to look pretty much the same.

By coincidence, Inverse telecine is something that I've been working on a lot lately. I think there are two concepts that are getting confused in this thread. Inverse telecine derived from 60i NTSC sources has been around for a long time and involves removing the redundant fields in the 2:3 NTSC pulldown sequence and adding a repeat field. The result in a MPEG transport stream is still interlaced but it can be reconstructed to yield 24p on the decoder end (but standard 60i can also yield 24p). The original reason for using inverse telecine was to save the 20% space that the repeated fields consume. In actual practice inverse telecine is troubleprone and something that both encoders and decoders struggle with and there are a lot of incompatibilties (especially getting the playout framerate to work properly). Poynton also mentions that it's complex and trouble-prone.

"Inverse telecine" is explicitly the reversion of a "telecine" process. Telecine in this case is refering to the original practice of converting a film source to a video source. The original understanding being that the resulting video master has an interlaced structure. This term can apply equally to 3:2 or 2:2 pulldowned material. Its nothing to do directly with transport streams. I'm not sure what you mean by "adding a repeat field" in the context you use it.

With 3:2 pulldowned 60i whether a transport stream encodes every repeat field or simply flags it for repeat is immaterial. The resulting decoded sequence is 60i and HAS to be decoded to 60i before deinterlacing regardless. This is also why repeat frame flags are near useless as a detection mechanism for deinterlacing as the flags are there solely to aid compression and do not have to be correct or consistent within a transport stream for the purposes of deinterlacing.

Inverse telecine itself is a very simple process. The complexity arises from the detection required to make the deinterlace correctly behave and subsequently apply the correct technique to create a true "inverse telecine" back to 24p. Detecting a 3:2 pulldown cadence is comparatively easy for automatic deinterlacers. Detecting a 2:2 pulldown cadence is comparatively difficult.

Once you have the 24p or 25p sequence whatever speed you play it back at and whether you use repeat frames to reach a desired refresh rate is a seperate issue from the inverse telecine part as you say...I think.


1080p24 on the other hand is a standard SMPTE format (274M IIRC) that is truly progressive with only one field per frame. Taking 1080i60 and converting it to true 1080p24 is what I assume JVC means by inverse telecine and I think this adds confusion by those who have always thought of this as the process of removing redundant fields and adding a repeat flag.
.

Are you referring to 1080psf here? "one field per frame" doesn't make sense in reference to 24p. 1080psf is essentially "48i" : imagine 60i without the 3:2 repeat cadence, little different to standard 50i with a 2:2 pulldown cadence (25fps rate excepted obviously). 24p is truly progressive and encoded as frames : fields do not come into it. 1080psf (progressive segmented frame) is not a consumer format and most people are unlikely to ever encounter it.

Inverse telecine is strictly the process of applying correct deinterlacing techniques to reconstruct a true 24p or 25p frame structure and its a very simple process in itself.

Your Sp7205 does not do this, it merely does 60hz 3-2 cadence display. Not a true frame rate conversion to 24p then displaying the frames at 48hz as the JVC brochure describes.


from the 7205 brochure regarding video compatibility :)
standard video (480i, 576i, 576i RGB SCART with adapter, NTSC, NTSC M 4.43, PAL: B, G, H, I, M, N; SECAM: M) including 60Hz to 48Hz conversion of NTSC film-based content

"Inverse telecine" is explicitly the reversion of a "telecine" process. Telecine in this case is refering to the original practice of converting a film source to a video source. The original understanding being that the resulting video master has an interlaced structure. This term can apply equally to 3:2 or 2:2 pulldowned material. Its nothing to do directly with transport streams. I'm not sure what you mean by "adding a repeat field" in the context you use it.


My point is that there are different conventions as to what inverse telecine means. To the broadcast industry and video encoder guys the term has been in widespread use and has everything to do with transport streams and the process of removing redundant fields and adding a repeat field for the decoder. If you read Poynton's digital video and HDTV book that is his (and only) use of the definition.

To a display guy the term means to take NTSC 1080i60 (decoded frames) and convert it to 1080p24, this is a much more recent invention and in fact the SMPTE 1080p24 spec (274M-2005) wasn't released until 2005. It's this process that JVC is talking about and my point is that it may be confusing to some people as it has nothing to do with the process described above by Poynton and in widespread use in the video broadcast industry.


Are you referring to 1080psf here? "one field per frame" doesn't make sense in reference to 24p.


This is just a symantics difference. I mean one progressive frame and not 1080psf. Some people use the term one field (complete progressive) per frame to denote what you're calling truly progressive.

I'm still not getting the exact differences in the way to do this...

It seems most 1080p LCD projectors are doing this no?
Reverse tecline then display it 96hz? A myriad of clever names for it? Cinema Reality? Ect..ect...