strangersonmyflight DVD Encoding Debate

[strangersonmyflight]

There aren't any 480p DVD's either,...

Uh-oh! You should do some further investigation on this. It is a common misconception that the "progressive DVD player" is actually doing something "extra", when in fact it is the opposite.

[mjones73]

Uh-oh! You should do some further investigation on this. It is a common misconception that the "progressive DVD player" is actually doing something "extra", when in fact it is the opposite.

Care to clue us in on what you ment by this? Ratman made a true statement that DVD's are not 480p, your comment has nothing to do with that fact.

[strangersonmyflight]

It is incorrect, but I know how he hates to be contested. Hence, I simply suggest he go do some more research.

[Ratman]

Uh-oh! You should do some further investigation on this. It is a common misconception that the "progressive DVD player" is actually doing something "extra", when in fact it is the opposite.

Uh-oh! You should do some further investigation on this!

The "progressive DVD player" is deinterlacing a 480i encoded video signal to 480p. That's "extra".

Please expand on, "...when in fact it is the opposite".

[mjones73]

Last I checked a progressive scan player does reverse 3:2 pulldown to rebuild full frames to display a movie the way it was intended on film so I'm kinda lost on what your progressive scan player comment ment, also your standard run of the mill DVD is going to be native 480i, if it's in any other format, it's not been encoded like a normal DVD and won't play in a normal DVD player. If either of those statements are incorrect how about enlightening me with a link or two showing me otherwise...

[raff]

Uh-oh! You should do some further investigation on this. It is a common misconception that the "progressive DVD player" is actually doing something "extra", when in fact it is the opposite.

Think you're mistaken here dude. Ratman is spot on.

[strangersonmyflight]

For a good long time, DVD's have been "progressive" encoded (namely movie DVD's, by virtue of their source). It's really a bad context to refer to it as either progressive or interlaced, as the greater important thing to note is that it is a full image that is stored in each frame. The exception being some DVD releases that come from a video source (like if you bought a Best of "Friends" DVD). In cases like that, it is kept in its interlaced state when encoded to the DVD (not saying the Friends DVD is certainly interlaced- that was just an example).

So most DVD's are encoded full frame for frame. It is the original DVD players that had the extra chore of slicing this signal into an appropriate interlaced output. The advent of progressive scan DVD players was not that they were doing someing "special" to achieve the progressive output. They simply skip the interlacing stage to give you the literal progressive frame that exists on the DVD itself. Where they are called upon to do some extra work is if they are deinterlacing a DVD with "interlaced" program material (which is the rare breed).

Hence the statement asking why there are no 480p DVD's is incorrect, because it literally is that way. Subsequentially, the comparison to 1080i==>1080p fails. Going from i to p can be a messy process to achieve high quality, while the reverse is relatively simple. That is why you will find that the original DVD players did the latter. The common misconception comes from when people see that progressive DVD players came after "regular" DVD players, hence they assume it does something "extra special" to create the progressive output. In reality, it was just a simpler implementation that was procedurally "closer" to the original media.

Addendum: The 3:2 pulldown pertains to frame rate matching from film to video, not an indication of interlacing vs. progressive. The 2 should not be confused.

I'm certain you will vehemently refuse this explanation, but there it is for all to read. Take it as you will (or not).

[Ratman]

And yet again...

Don't confuse film vs. video vs. frames vs. fields.

All DVD's are encoded at 480i no matter the source material(s) to comply with NTSC standards.

[strangersonmyflight]

The output has to conform to NTSC standards. That has no bearing on the media within. As long as you have an interlacing stage, it is irrelevant.

As an experiment, play your DVD from your computer's media player. Does it degrade to a "single field" when you pause it? If not, do you see any signs of deinterlacing artifacts? You won't because you will be viewing the full frame of the video as it existed on the disc. Now if you were importing program material from a VCR, then you would most certainly be dealing with single-field-on-pause or single-frame-with deinterlace-artifacts issues.

[57U]

I think you're confusing anamorphic and non-anamorphic.

DVDs are 480i and PS DVD players "deinterlace" the signal. If they didn't, why the hell would they have a deinterlacer?

Also, non PS DVD players play DVDs. They sure as hell didn't do any "extra steps" many years ago when they were invented. Non-PS players didn't, and don't, interlace a PS signal.

DVDs are encoded as 480i.

[mjones73]

You might want to read this..

http://www.dvdfile.com/news/special_report/production_a_z/3_2_pulldown.htm

Specially the comment
"When a film source is encoded for presentation on DVD, it is stored at 24 frames per second; each video frame contains all the picture information from each film frame. There is no redundancy or duplication. Such a transfer is written to DVD as 720-pixel wide by 480-pixel high interlaced frames (where each frame contains two 720 by 240 fields), and there are only 24 frames for each second of film. This is known as 480i24."

So yes the data for the full frame is on the disk, it's still written in seperate 720x240 fields hence it's stored in an interlaced format.

Might want to do some research of your own next time...

[strangersonmyflight]

I think you're confusing anamorphic and non-anamorphic.

DVDs are 480i and PS DVD players "deinterlace" the signal. If they didn't, why the hell would they have a deinterlacer?

...to provide compatibility with the rare breed interlaced DVD program. All you got to do is open up your player and note the signal traces. The interlaced "output" goes through an extra video stage to interlace it. The progressive output takes a more direct route (this part is less relevant these days, given that some DVD players have aspired to further video processing to do scaling to HDTV resolutions.

Also, non PS DVD players play DVDs. They sure as hell didn't do any "extra steps" many years ago when they were invented. Non-PS players didn't, and don't, interlace a PS signal.

This is a very simple process, so to find a DVD player doing it is hardly surprising. Game consoles have done it for years.

DVDs are encoded as 480i.

Well, some are. It's irrelevant to the actual output of the player. The final video stages determine the output format, regardless of the media.

[57U]

Strangers, you're right and the other 10,000 people on this site are wrong, as is the article in post 73. We know this based on previous experience.

Once you realize you're fallible, perhaps you may wish to think before typing.

The world (and others on this site) are not out to get you, but you won't begin to learn until you realize that some others actually do know more than you do on certain topics.

[Ratman]

It is incorrect, but I know how he hates to be contested. Hence, I simply suggest he go do some more research.

I guess this can be applicable to others as well. :whistle:

[strangersonmyflight]

"Such a transfer is written to DVD as 720-pixel wide by 480-pixel high interlaced frames (where each frame contains two 720 by 240 fields), and there are only 24 frames for each second of film. This is known as 480i24."

Here's where the fine distinction is- ok, so you have the frames stored in fields. Does this mean that each field represents a unique point in time, such as you find in a "conventional" interlaced setup? No it is not. You have fields that are inherently intended to be shown together to create a frame. It's that 1 every 3 frames (or whatever the rate of occurance) that is truly an "interlaced" frame generated from fields of 2 different point in time. So if you want to be technical about it, it is primarily a progressive process punctuated by regular interlaced moments, which nicely allows an easy frame rate conversion. It's a hybrid process of sorts, but not particularly equivalent to the standard "interlace" scheme of NTSC video, in the way one field relates to the next.

To casually say all DVD is 480i, implies that there is no frame (whether or not it ultimately comes from 2 fields or not) that contains the full 480 lines of information from a single point in time. This is just not the case. A full frame of the video does exist for a given point in time. This is another unfortunate case where a not-fully-accurate casual designation results in a considerable misconception of the process altogether. They called it "480i" for lack of a simpler explanation, however that does not then mean it is clear and free "interlaced" in the same manner you would describe other more conventional interlaced sources. There's a fine distinction here. Hence, making a comparison of video sources 1080i to 1080p becomes a bit strained. Hopefully 1080p24 is a "true" progressive format, not just a 3:2 hack derived from 1080i30, or that will be just another example of HDTV standards taking a "punt".

[mjones73]

The DVD is still recorded in an interlaced format regardless of what the player does with it to display an image...

[raff]

Strangers,
I've come to determine you'll disagree about anything just for the sake of it. I've done this for a long time, I know several long term A/V folks and no one has ever argued that a DVD is not 480i.

Perhaps you know something that no one else does, or maybe you just decided to digest info the way you see fit. Either way, you're wrong.

[strangersonmyflight]

Your post was irrelevant to the topic. What you seem to miss is that I do bother to make the fine distinctions to capture the heart of the matter. I don't just blindly parse some website for a combination of words so I can come back here and say, "see, it says it right here by virtue of the wording!". I'll bother to go through what they are actually trying to say by the words. Do you?

Just say you disagree.

[raff]

Your post was irrelevant to the topic. What you seem to miss is that I do bother to make the fine distinctions to capture the heart of the matter. I don't just blindly parse some website for a combination of words so I can come back here and say, "see, it says it right here by virtue of the wording!". I'll bother to go through what they are actually trying to say by the words. Do you?

Just say you disagree.

As usual you're argumentative and arrogant. To make statements about other people's "parsing" of information is both judgmental and idiotic. There are a lot of highly technical people, including myself, on this board that don't agree with you on this subject. As a matter of fact, no one agrees with you on this subject. Does that, by some chance, lend to the possibility that you may be wrong. Just this one time? Is that so out of the realm of possibility?

[raff]

Perhaps this will help you out Strangers. Something similar to it could have led to your Progessive Scan confusion with DVD's, but this is more clear and concise.

It's quoted from Richard. An ISF Engineer who runs another forum.

While DVD movies are 480I sources they can be encoded with progressive flags during mastering telling the scaler in the DVD player how to recreate the image in 480P.


Note that they are 480i sources. Flags have to be ADDED to the data, to instruct the scaler on the best way to display Progressive.

[Matt27]

Woah it's ok to admit when your wrong, it's another thing to keep blabbing false accusations when you think your right.

DVD is 480i, progressive players deinterlace it to 480p, it's as simple as that.

I don't see the complication, if dvd's were truly progressive scan, then i would'nt need a progressive scan player nor a deinterlacer.

It's ok to admit that your wrong man, just admit it..your wrong!!!

We all learn form others.

[mjones73]

I'll bother to go through what they are actually trying to say by the words. Do you?

Maybe you should stop because your drawing incorrect conclusions on how DVD's work in your mind.. Tech articles such as the one I posted showing your wrong don't have hidden meanings, the information is right there in black and white.

We understand how a DVD player deals with data on a DVD regardless if it's an interlaced or progressive player. That information has no impact on the FACT that the data is stored interlaced on the DVD. If you have hard proof that it's not other then your obvious misunderstanding of how DVD's are made, spare us please.

[Ratman]

This may be of interest (excerpt from: http://www.dvddemystified.com/dvdfaq.html#1.4 )


[1.40] What's a progressive DVD player?
A progressive-scan DVD player converts the interlaced (480i) video from DVD into progressive (480p) format for connection to a progressive-scan display (31.5 kHz or higher). Progressive players work with all standard DVD titles, but look best with film source. The result is a significant increase in perceived vertical resolution for a more detailed and film-like picture. Since computers use progressive-scan monitors, DVD PCs are by definition progressive-scan players, although quality varies quite a bit (see 4.1 and 2.12).

There's enormous confusion about whether DVD video is progressive or interlaced. Here's the one true answer: Progressive-source video (such as from film) is usually encoded on DVD as interlaced field pairs that can be reinterleaved by a progressive player to recreate the original progressive video. See 3.8 for further explanation of interlaced and progressive scanning.

You must use a progressive-scan display in order to get the full benefit of a progressive-scan player. However, all progressive players also include interlaced outputs, so you can use one with a standard TV until you upgrade to a progressive TV. (You may have to use a switch on the back of the player to set it to interlaced output.)

Toshiba developed the first progressive-scan player (SD5109, $800) in mid 1998, but didn't release it until fall of 1999 because of copy protection concerns. Panasonic also released a progressive-scan player (DVD-H1000, $3000) in fall of 1999. Many manufacturers have released progressive models since then at progressively cheaper prices (pun intended). It's also possible to buy an external line multiplier to convert the output of a standard DVD player to progressive scanning.

Converting interlaced DVD video to progressive video involves much more than putting film frames back together. There are essentially three ways to convert from interlaced to progressive:
1- reinterleaving (also called weave). If the original video is from a progressive source, such as film, the two fields can be recombined into a single frame.
2- Line doubling (also called bob). If the original video is from an interlaced source, simply combining two fields will cause motion artifacts (the effect is reminiscent of a zipper), so each line of a single field is repeated twice to form a frame. Better line doublers use interpolation to produce new lines that are a combination of the lines above and below. The term line doubler is vague, since cheap line doublers only bob, while expensive line doublers (those that contain digital signal processors) can also weave.
3- Field-adaptive deinterlacing, which examines individual pixels across three or more fields and selectively weaves or bobs regions of the picture as appropriate. Chips to do this used to cost $10,000 and up, but the feature is now appearing in consumer DVD players.
4- And there's also a fourth way, called motion-adaptive deinterlacing, which examines MPEG-2 motion vectors or does massive image processing to identify moving objects in order to selectively weave or bob regions of the picture as appropriate. Most systems that do this well cost $50,000 and up (aside from the cool but defunct Chromatic Mpact2 chip).

There are three common kinds of deinterlacing systems:
1- Integrated. This is usually best, where the deinterlacer is integrated with the MPEG-2 decoder so that it can read MPEG-2 flags and analyze the encoded video to determine when to bob and when to weave. Most DVD computers use this method.
2- Internal. The digital video from the MPEG-2 decoder is passed to a separate deinterlacing chip. The disadvantage is that MPEG-2 flags and motion vectors may no longer available to help the deinterlacer determine the original format and cadence. (Some internal chips receive the repeat_first_field and top_field_first flags passed from the decoder, but not the progressive_scan flag.)
3- External. Analog video from the DVD player is passed to a separate deinterlacer (line multiplier) or to a display with a built-in deinterlacer. In this case, the video quality is slightly degraded from being converted to analog, back to digital, and often back again to analog. However, for high-end projection systems, a separate line multiplier (which scales the video and interpolates to a variety of scanning rates) may achieve the best results.

Most progressive DVD players use an internal deinterlacing chip, usually from Genesis/Faroudja. Some use MPEG decoders with integrated deinterlacing. Some, such as Toshiba's "Super Digital Progressive" players and Panasonic's progressive-scan player add 4:4:4 chroma oversampling, which provides a slight quality boost from DVD's native 4:2:0 format. Add-on internal deinterlacers such as the Cinematrix and MSB Progressive Plus are available to convert existing players to progressive-scan output. Faroudja, Silicon Image (DVDO), and Videon (Omega) line multipliers are examples of external deinterlacers.

A progressive DVD player has to determine whether the video should be line-doubled (bobbed) or reinterleaved (weaved). When reinterleaving film-source video, the player also has to deal with the difference between film frame rate (24 Hz) and TV frame rate (30 Hz). Since the 2-3 pulldown trick can't be used to spread film frames across video fields, there are worse motion artifacts than with interleaved video. However, the increase in resolvable detail more than makes up for it. Advanced progressive players such as the Princeton PVD-5000 and DVD computers can get around the problem by displaying at multiples of 24 Hz such as 72 Hz, 96 Hz, and so on.

A progressive player also has to deal with problems such as video that doesn't have clean cadence (as when it's edited after being converted to interlaced video, when bad fields are removed during encoding, when the video is speed-shifted to match the audio track, and so on). Another problem is that many DVDs are encoded with incorrect MPEG-2 flags, so the reinterleaver has to recognize and deal with pathological cases. In some instances it's practically impossible to determine if a sequence is 30-frame interlaced video or 30-frame progressive video. For example, the documentary on Apollo 13 is interlaced video encoded as if it were progressive. Other examples of improper encoding are Titanic, Austin Powers, Fargo, More Tales of the City, the Galaxy Quest theatrical trailer, and The Big Lebowski making-of featurette.

One problem is that many TVs with progressive input don't allow the aspect ratio to be changed -- they assume all progressive-scan input is anamorphic. When a non-anamorphic (4:3) picture is sent to these TVs they distort it by stretching it out! Before you buy a DTV, make sure that it allows aspect ratio adjustment on progressive input. Or get a player with an aspect ratio control option that "windowboxes" 4:3 video into a 16:9 rectangle by squeezing it horizontally and adding black bars on the side. Because of the added scaling step this degrades picture quality, but at least it gets around the problem.

Just as early DVD computers did a poor job of progressive-scan display of DVDs, the first generations of progressive consumer players are also a bit disappointing. But as techniques improve, and as DVD producers become more aware of the steps they must take to ensure good progressive display, and as more progressive displays appear in homes, the experience will undoubtedly improve, bringing home theaters closer to real theaters.

And... for more enlightenment:


[3.4] What are the video details?
DVD-Video is an application of DVD-ROM, according to the specification created by the DVD Forum (see 6.1). DVD-Video is also an application of MPEG-1, MPEG-2, Dolby Digital, DTS, and other formats. This means the DVD-Video format defines subsets of these standards and formats to be applied in practice to make discs intended for DVD-Video players. DVD-ROM can contain any desired digital information, but DVD-Video is limited to certain data types designed for television reproduction.

A disc has one track (stream) of MPEG-2 constant bit rate (CBR) or variable bit rate (VBR) compressed digital video. A restricted version of MPEG-2 Main Profile at Main Level (MP@ML) is used. SP@ML is also supported. MPEG-1 CBR and VBR video is also allowed. 525/60 (NTSC, 29.97 interlaced frames/sec) and 625/50 (PAL/SECAM, 25 interlaced frames/sec) video display systems are expressly supported. Coded frame rates of 24 fps progressive from film, 25 fps interlaced from PAL video, and 29.97 fps interlaced from NTSC video are typical. MPEG-2 progressive_sequence is not allowed, but interlaced sequences can contain progressive pictures and progressive macroblocks. In the case of 24 fps source, the encoder embeds MPEG-2 repeat_first_field flags into the video stream to make the decoder either perform 2-3 pulldown for 60Hz NTSC displays (actually 59.94Hz) or 2-2 pulldown (with resulting 4% speedup) for 50Hz PAL/SECAM displays. In other words, the player doesn't "know" what the encoded rate is, it simply follows the MPEG-2 encoder's instructions to produce the predetermined display rate of 25 fps or 29.97 fps. This is one of the main reasons there are two kinds of discs, one for NTSC and one for PAL. (Very few players convert from PAL to NTSC or NTSC to PAL. See 1.19.)

Because film transfers for NTSC and PAL usually use the same coded picture rate (24 fps) but PAL resolution is higher, the PAL version takes more space on the disc. The raw increase before encoding is 20% (480 to 576), but the final result is closer to 15%, depending on encoder efficiency. This translates to an increase of 600 to 700 megabytes on PAL discs compared to NTSC discs.

It's interesting to note that even interlaced source video can be rendered as progressive-structured MPEG pictures by a good encoder, with interlaced field-encoded macroblocks used only when needed for motion. Most film sources are encoded at 24 frames per second (the inverse telecine process during encoding removes duplicate 2-3 pulldown fields from the videotape source, and the remaining field pairs, although technically in interlaced form, can be re-interleaved by a progressive player). Most video sources are encoded at 25 or 30 interlaced frames per second. These may be mixed on the same disc, such as an interlaced-source logo followed by a progressive-source movie.

See 3.8 for an explanation of progressive and interlaced scanning. See 1.40 for progressive-scan players. See the MPEG page <www.mpeg.org> for more information on MPEG-2 video.

Picture dimensions are at maximum 720x480 (for 525/60 NTSC display) or 720x576 (for 625/50 PAL/SECAM display). Pictures are subsampled from 4:2:2 ITU-R BT.601 down to 4:2:0 before encoding, allocating an average of 12 bits/pixel in Y'CbCr format. (Color depth is 24 bits, since color samples are shared across 4 pixels.) DVD pixels are not square (see 3.5). The uncompressed source is 124.416 Mbps for video source (720x480x12x30 or 720x576x12x25), or 99.533 or 119.439 Mbps for film source (720x480x12x24 or 720x576x12x24). In analog output terms, lines of horizontal resolution is usually around 500, but can go up to 540 (see 3.4.1). Typical luma frequency response maintains full amplitude to between 5.0 and 5.5 MHz. This is below the 6.75 MHz native frequency of the MPEG-2 digital signal (in other words, most players fall short of reproducing the full quality of DVD). Chroma frequency response is half that of luma.

Allowable picture resolutions are:
MPEG-2, 525/60 (NTSC): 720x480, 704x480, 352x480, 352x240
MPEG-2, 625/50 (PAL): 720x576, 704x576, 352x576, 352x288
MPEG-1, 525/60 (NTSC): 352x240
MPEG-1, 625/50 (PAL): 352x288

Different players use different numbers of bits for the video digital-to-analog converter, wit the best-quality players using 10 or 12 bits. This has nothing to do with the MPEG decoding process, since each original component signal is limited to 8 bits per sample. More bits in the player provide more "headroom" and more signal levels during digital-to-analog conversion, which can help produce a better picture.

Maximum video bit rate is 9.8 Mbps. The "average" video bit rate is around 4 Mbps but depends entirely on the length, quality, amount of audio, etc. This is a 31:1 reduction from uncompressed 124 Mbps video source (or a 25:1 reduction from 100 Mbps film source). Raw channel data is read off the disc at a constant 26.16 Mbps. After 8/16 demodulation it's down to 13.08 Mbps. After error correction the user data stream goes into the track buffer at a constant 11.08 Mbps. The track buffer feeds system stream data out at a variable rate of up to 10.08 Mbps. After system overhead, the maximum rate of combined elementary streams (audio + video + subpicture) is 10.08. MPEG-1 video rate is limited to 1.856 Mbps with a typical rate of 1.15 Mbps.

Still frames (encoded as MPEG I-frames) are supported and can be displayed for a specific amount of time or indefinitely. These are used for menus or slideshows. Still frames can be accompanied by audio.

A disc also can have up to 32 subpicture streams that overlay the video for subtitles, captions for the hard of hearing, captions for children, karaoke, menus, simple animation, etc. These are full-screen, run-length-encoded bitmaps with two bits per pixel, giving four color values and four transparency values. For each group of subpictures, four colors are selected from a palette of 16 (from the YCbCr gamut), and four contrast values are selected out of 16 levels from transparent to opaque. Since one of the four values is usually 100% transparency (to let the video show through), only three combinations of colors and transparencies are left, making overlay graphics rather crude. Subpicture display command sequences can be used to create effects such as scroll, move, color/highlight, and fade. The maximum subpicture data rate is 3.36 Mbps, with a maximum size per frame of 53220 bytes.

In addition to subtitles in subpicture streams, DVD also supports NTSC Closed Captions. Closed Caption text is stored in the video stream as MPEG-2 user data (in packet headers) and is regenerated by the player as a line-21 analog waveform in the video signal, which then must be decoded by a Closed Caption decoder in the television. Although the DVD-Video spec mentions NTSC only, there is no technical reason PAL/SECAM DVD players could not be made to output the Closed Caption text in World System Teletext (WST) format; the only trick is to deal with frame rate differences. Unfortunate note: DVD Closed Caption MPEG-2 storage format is slightly different than the ATSC format. See 1.45 for more about Closed Captions.

[mjones73]

Nice research there Ratman.

[jco]

I have a question here. I understand how a 24fps movie is converted to 480i/60 on the output of a 480i/60 DVD player (non-progressive). You get 3 fields then 2 fields then 3 fields and so on for each original 24fps film frame. for a total of 60 fields ( 12 triples and 12 doubles ) each second displaying the 24 original film frames. this has been done like this for many years with standard NTSC 480i/60 video. BUT when you switch the DVD player to progressive output WHAT HAPPENS? Is the output 480P/24?
is it 480p/30? maybe 480p/60 with some frame doubling and/or tripling going on? I dont see how it could possible be a true discrete 480p/60 output without frame doubling or tripling becuase that would require twice as much data as whats on the 480i/60 encoded DVD. What is the output format specifically including FRAME RATE? Is the frame rate uneven time between frames similar to the 3/2 cadence of 480i/60? I dont see how it works anywhere in my travels.....

[Ratman]

...this has been done like this for many years with standard NTSC 480i/60 video. BUT when you switch the DVD player to progressive output WHAT HAPPENS? Is the output 480P/24?.

Standard NTSC is 480i/30
Progressive output is 480p/60
2:3 pulldown will convert 480i/24 to 480p/60

http://www.avdeals.com/classroom/Proscanexplained.htm

To produce a higher resolution picture, the NTSC decided to use interlacing in its original TV standards (basically as a type of compression). Interlacing takes two fields, each being 1/60th of a second, with half the information (every other line) each and combines them into one 1/30th of a second frame with the complete picture. So what looks to the eye as 30 fps is actually 60 interlaced fields per second. The advantage is that less lines are being "drawn" on the screen at one time, so the set can look like it is a higher resolution with less expensive circuitry.

It is called progressive scanning when a television displays a complete frame, instead of every other line, every 60th of a second. This gives a more stable looking picture, but means you would need a display that can scan twice as fast to produce a whole picture in 1/60th of a second instead of half the picture. And there are multiple frame rates for both interlace and progressive in HDTV. Confused? Well, it gets worse.

The standard for NTSC analog television is 525 lines at an interlaced 30 fps. This can also be written as 525i. Only 480 lines actually consist of displayed picture information, with the rest being used for broadcasting information. As a result, most TV now is considered 480i. The standards for digital television consist of 18 different resolution, frame rate and aspect ratio combinations. The most basic digital television standard is the 4:3 aspect ratio using 480p (progressive) with 24 fps (written as 480p/24 or 480/24p), instead of 480i with 30 fps (written 480i/30 or 480/30i).

[mjones73]

Ohh and to answer your test -

"As an experiment, play your DVD from your computer's media player. Does it degrade to a "single field" when you pause it?"

No because computer based DVD players need to be progressive in order to support the fact all PC monitors are progressive.

[strangersonmyflight]

So the mechanics of the data transfer are geared for interlaced output. You seem infatuated with that point to consider any other meaning. The fact remains that the resulting image is a full, progressive image of the film for a particular point in time. That part you cannot dispute, and is even explicitly stated in the quote mjones gave (I would have thought that would have been the end of it, but you insist on beating a dead horse since you have the mods standing behind you for support). The flags are simply there to tell the DVD player, "Hey, we're gonna be sending down this full image info down this interlaced data link, so act accordingly."

This is quite different than the typical interlaced definition whereby you are sending alternating fields each updating ahead in time by 1/x sec.

Arguing that DVD movies are progressive-based vs. interlaced-based is akin to arguing that because my computer gets internet service through LAN connection and your compouter gets internet service by directly connecting to a DSL modem, then we are getting "different internets" (???). Rest assured, it is the same internet- just a difference in the delivery method. No information added or subracted or modified...the same internet.

Here's another way to look at it- since LCD and plasma displays update on a screen-by-screen basis, instead of line-by-line, does that then mean that they are not "true" progressive scan displays? Afterall, progressive scan explicitly means drawing the image with one line right after the next. So by that definition, you should gather that only progressive CRTs can be true progressive scan monitors. Getting hung up on this (similar to being hung up on how data happens to be delivered on a DVD), ends up largely pointless. What really matters is what the end result is- a full screen image at a specific point in time. Under that qualification, both LCD and plasma are capable of a full-screen image eqivalent to what you get with a progressive scan CRT. Informally, they are all referred to as progressive scan capable devices. How the image is created is largely irrelevant.

[strangersonmyflight]

Ohh and to answer your test -

"As an experiment, play your DVD from your computer's media player. Does it degrade to a "single field" when you pause it?"

No because computer based DVD players need to be progressive in order to support the fact all PC monitors are progressive.

What, do you think the DVD video magically becomes progressive just because the computer-based DVD player needs to be progressive?!

If movies on DVD players were interlaced video, then the solution would be very easy- you are simply shown a single field. This would be very obvious.

However, this is unnecesary, because the info to build the actual progressive image from a movie on a DVD is already there, w/o any form of motion interpolation, tweaking, etc. Hence, the resulting output is as progressive as any other progressive source (w the exception of the pulldown frame). This is not to say that extra computation and processing can be added to further tweak that pulldown frame. It's just not critically necessary to gain access to progressive output for a movie DVD. Now where that extra hardware really comes into play is when it comes to processing/scaling/deinterlacing/whatever those DVD's that contain explicitly interlaced video (such as video-based TV shows). Those are certainly interlaced-based, and can certainly benefit from some digital dicing to come up with a presentable image for today's progressive displays. However, it seems that HDTV's have also evolved the same processing electronics so that they can take any kind of input and work up an image that is native to the final display mechanism. One may do a better job than the other, but there's not much to note there other than that.

[jco]

If a DVD player when set to progressive output is actually putting out a 480P/60 signal then it makes sense, you get 12 triple frames and 12 double frames from the 24P material. But it isnt really true 480P/60 recording and playback, its just P24 upcoverted to P60 via the frame tripling and doubling. so its really no better than P24, worse actually becuase the timing is uneven, If the DVD player and TV could do 480P/48 or 480P/72 that would be better but its probably not economically feasable to add those rates to the monitors at this point....

[raff]

The fact remains that the resulting image is a full, progressive image of the film for a particular point in time.


You are so unwilling to be wrong, that you will resort to pulling out this dreck! You're obviously much smarter than we troglodytes. Perhaps everyone else on this board should revert to picking nits off their mates, and trying to create fire.

Oh, and since you asked for it before, I/We disagree...

[strangersonmyflight]

Well, I would submit that it is not really a cost issue for consumer monitors that is a barrier. It just wouldn't gain anything since the film source isn't offering anything above 24 fps, in the first place. As you correctly surmised, doubling and tripling frames does not really double/triple the motion resolution of the original material. It just enables compatibility to other video formats (and this is pretty much handled by the HDTV conversion processing, anyway). The real barrier is the movie industry, who remains woefully behind in updating this specification. I know there are some here who absolutely deny that stuttering and motion artifacts are perceptible at 24 fps (on an 80 in screen, no doubt), but there ya go. If ever there was day where they tried to show a major sport event in 24p on an HDTV channel, I'm pretty sure it would be laid to rest pretty quick that 24 fps is quite inadequate for fast moving, action scenes, period.

[strangersonmyflight]

You are so unwilling to be wrong, that you will resort to pulling out this dreck! You're obviously much smarter than we troglodytes. Perhaps everyone else on this board should revert to picking nits off their mates, and trying to create fire.

Oh, and since you asked for it before, I/We disagree...

This is very simple- is it your understanding that the images on a movie DVD are composed of:

field #1 @ t=1/24 sec
field #2 @ t=2/24 sec
field #3 @ t=3/24 sec
.
.
.

If you genuinely understand the difference between interlace and progressive, this should be simple for you to answer. Yes or no?...

No need for the gratuitous melodramatics. This will not build your case any further, other than revealing your own lack of confidence. I must admit, life must be easy for someone who never steps out on a limb. Would you be so bold had you not had the backing of your "god-like" mods? I don't think so. That's pretty pathetic.

[Razor8]

Strangers, what is your major malfunction? This may come as a surprise to you but you take "playing on words" to another level. You're constantly "slightly" changing the point which only leads to another "vague" running off of the mouth. People here who disagree with you have presented evidence to support their claims. You have not. Without some evidence its just hogwash. Razor

[strangersonmyflight]

It's no "playing of words". It's a simple question I posted above. Either you understand the material well enough to give an answer, or you don't. (Quite possible you and others like you don't know the material at all, and instead wait for your lordly moderators to give an answer for you to then run behind- that's not "learning" from those who are smarter. You are just aping answers off of someone else's test sheet, and then proclaiming how well you know it all)

So, what's it gonna be, skippy? Yes or no?

[mjones73]

"What, do you think the DVD video magically becomes progressive just because the computer-based DVD player needs to be progressive?!"

No, the computer based software performs the same function as a progressive scan player. Believe it or not, that is possible.

Argue all you want, see the facts in any form you want to interpret them in, you are still WRONG. It's very possible you don't know the material at all because you keep posting the WRONG answer and the WRONG facts backing it. All you keep posting is your interpretation of the facts and it’s still WRONG. Find it funny that not one person has backed you on your claims? Do you really think every member here is afraid to challenge the “lordly moderators” as you call us besides yourself? Again, spare us the crap please, you just keep spewing out more BS in this post.

[mjones73]

Ohh and by the way it's not

field #1 @ t=1/24 sec
field #2 @ t=2/24 sec
field #3 @ t=3/24 sec

It's

field #1 @ t=1/48 sec
field #2 @ t=2/48 sec
field #3 @ t=3/48 sec

If you run at 48 fields per second you get your interlaced 24 frames per second. With reverse 3:2 pulldown, certain fields are repeated to get the output at the NTSC standard 29.97 frames per second.

Again, I ask you to show some hard proof backing your claims other then your interpretation of the facts.

[57U]

In the first post of this thread you stated two things.

1. You said that Ratman was wrong about DVDs not being 480P (Ratman had stated in another thread that they are 480i, as have numerous others).

2. You said that PS do not do "extra", that they do the opposite (Nothing?).

Everyone on this thread (except you) has presented evidence including several web-links regarding the fact that DVDs are encoded as 480i and that a PS DVD player deinterlaces this signal (does extra).

You have continued to ramble on about various subjects, including various TV types which has nothing to do with how a DVD is encoded and you have not been able to present a single link backing up your claims as presented in post 1.

QED.

[Matt27]

:boo2: I can't beleive you strangers..

Just admit that your wrong, it's ok to make mistakes you know, were all human.

DVD's are 480i, a progressice scan player deinterlaces the 480i dvd to 480p progressive.It's as simple as that...If dvd's were truly progressive scan then i would'nt need a deinterlacer nor a Progressive Scan player.

As far as i'm concerned all that you are doing is trying to convince everybody that dvd's are 480p when you have no actual proof to back up you answers.

I honestly don't see the complication here, just drop it.

And the mods are just doing there job, to prevent people like you from ruining discussions.

If you "DO" have factual proof that dvd's are 480p then we would like to see it.

Untill then your answers don't mean squat :rmoon2: !!!

[strangersonmyflight]

Ohh and by the way it's not

field #1 @ t=1/24 sec
field #2 @ t=2/24 sec
field #3 @ t=3/24 sec

It's

field #1 @ t=1/48 sec
field #2 @ t=2/48 sec
field #3 @ t=3/48 sec



...and what do you think that field comes from at "t=2/48"? Do you think it is a unique field for that specific time point. How can it be? The movie itself is only updating at 24 fps. Hence you have simply only achieved taking a snapshot of an alternative field of the same frame that existed at "t=1/48 sec". Together, the 2 fields form a contiguous, full frame image unique to "t=1/48 sec". There's your "progressive scan" image.

Outside all of this, do you have an answer for the simple question (being that the distinction of 1/24 vs. 1/48 is largely an irrelevant distinction when it comes to film-based transfers)? Is each successive field representative of a film frame from a unique and different time point? Yes or no?

[Matt27]

Now your just being abnoxious, and trying to back up your lies and lies of answers.

Please just accept the fact that your wrong.It's ok take a deep breath....

I would like to see some actual proof of where you got these facts by the way.

[strangersonmyflight]

:boo2: I can't beleive you strangers..

Just admit that your wrong, it's ok to make mistakes you know, were all human.

DVD's are 480i, a progressice scan player deinterlaces the 480i dvd to 480p progressive.It's as simple as that...If dvd's were truly progressive scan then i would'nt need a deinterlacer nor a Progressive Scan player.

As far as i'm concerned all that you are doing is trying to convince everybody that dvd's are 480p when you have no actual proof to back up you answers.

I honestly don't see the complication here, just drop it.

And the mods are just doing there job, to prevent people like you from ruining discussions.

If you "DO" have factual proof that dvd's are 480p then we would like to see it.

Untill then your answers don't mean squat :rmoon2: !!!

...and how did you come to these notions? Because you read it somewhere? Because it was spoonfed to you? That's not learning. That's just reading the topical issues w/o really bothering to fully comprehend the actual matter from top to bottom. You may feel comfortable with that sort of "learning", but it won't get you very far other than becoming the "moderator's pet".

Just answer the question...a simple question if you have really "learned" from things you've read in the past. Save the dogma. Chanting it over and over won't make it any more true.

Is it your understanding that each successive field in a DVD movie comes from a unique frame from a unique time point? A simple question, if you understand the material...

If you are finding difficulty with this question, then who are you to rail against me about what is right or wrong and what constitutes "proof"? You'll have neither the means to determine what is right or wrong or what the "proof" is really proving. You are simply waiting for consensus opinion to show up, after which you jump on the bandwagon. That's not intelligence. It's the precipice to mob mentality. I see even the the well heralded personas have taken a mode of hesitation to answering this very simple question. Shouldn't be this way. If you really know the material, the answer is simple. If you have any integrity, you will at least give the proper answer and admit how you find this strangely counter-indicative to the other material you have read/cited on the subject.

[Matt27]

NO!!

All i know is that the dvd player deinterlaces it to 480p and whoala!!! :whistle:

As simple as that,I'm sorry that i'm stupid and your the video wizard.I will now bow my head to you in respect of your knowledge.lol.lol.lol.lol.

I'm sorry i just could'nt help it. :rofl2:

[mjones73]

Time point has nothing to do with it, the frames are split into two fields, the fields are stored seperately and showed back sequentially to build the interlaced frame. In order to convert the video to NTSC format at playback, flags are inserted telling the mpeg decoder to repeat certain fields to achive the proper frame rate needed. Yes technically the data for the full frame is on the DVD, it's still stored in two interlaced seperate fields though, not as one full frame therefore the DVD is interlaced, how hard is that to understand?

I'll ask you yet again, if I'm wrong, show me some hard proof, not your made up reason I'm wrong. Until then I'm done wasting my time on you and I encourage other members to resist the urge to argue anymore with you.

[strangersonmyflight]

Yes technically the data for the full frame is on the DVD,...

That is all you need to know. You have the full image in the data, hence it is a trivial step to then become "progressive".

By making this statement, you have then answered my "simple question". Since you are evasive to give a direct answer, I will give it for you. The answer is "no", the images in a movie DVD's are not encoded in such a manner. If they were, then there would be some substance to "most DVDs" being interlaced. You should also note that your original quote of "proof" on the subject also cited that there is no duplicated frames involved. Hence it is doubtful that data is being spooled off the disc in 1/48 sec chunks. That would result in...duplicated frames and a lot of wasted space. You achieve the matching of frame rates via electronic buffers and pulldown at the very end of the chain, NOT on the encoding of the disc.

Hence, the proper sequence you find on a movie DVD:

field #1, t=1/24 sec
field #2, t=1/24 sec (field #1 + field #2 ==> 1 full progressive style frame)
field #3, t=2/24 sec
field #4, t=2/24 sec (field #3 + field #4 ==> 1 full progressive style frame)
.
.
.

...and since people keep citing this as "proof", it bears repeating that the reason you have a deinterlacer in your progressive scan DVD player is to enable progressive output from those video-based DVDs that are truly interlaced productions (videotape shot TV shows) in every meaning that interlacing implies. Of more crucial importance, the "deinterlacer" is only a sub-function (as such, hardly proof of anything in of itself) of a greater hardware processing that handles high-quality scaling, interpolations, filtering, etc which constitutes the HDTV output for various HDTV standards.

This is not twisting words or meanings. This is taking account of the fine details and distinctions to penetrate the veil of topical misconception.

Expanding upon this, DVD is essentially a progressive media when it comes to 24 fps movies. Arguably it could go as far as being able to provide 30 fps progressive (by extension of interlaced-60 capability), if the "flags" are there to support it. Could it do progressive 60? Most likely not, as that would require greater frame updates than the standard can offer. (Now technically, you could argue it is not an impossibility at all given the advent of 2x, 4x, 8x DVD drives, but won't be of much use unless the DVD standard has support for that.)

[Matt27]

Untill "WE" ( The majority of the forum) see where you have gotten these facts,your answers are considered invalid.

At least show us a link, so we can give the credit you disserve.

[strangersonmyflight]

"YOU" wouldn't know right from wrong or proof from disproof (I could present all sorts of myraid charts, graphs, quotations from websites- would it make a difference? You don't have the expertise to understand them in the first place). "YOU" are simply following consensus and taking for granted it must be "right". So you are hardly the one to proclaim "invalidity". Weren't you the one who couldn't tell the difference between "mps", Mb/s, and MB/s? Who cares, right? ...as long as it's a big, impressive, number, right?

You couldn't tell the difference between right or wrong, given your own devices. The only answer you really can muster is that you disagree and choose to follow the consensus out of not knowing any better. No harm in doing that- just be honest about it. Perhaps, your greatest failing on this has to do with what you consider as "proof". Because you find it in some website, makes it proof? Because it throws about some heavy lingo and buzzwords, it must be proof? I could find you a dozen quotes off the internet expounding the virtues of Monster cable at being able to give a "smoother sound", less distortion, greater dynamic range, clearer highs, etc. Is that then proof? Of course not. It's not impossible to find "good" information on the internet. You just shouldn't assume all information on the internet is "good". It also doesn't hurt to have a decent technical grasp of the material from your personal study or career to help you sort through the BS. That's where the real knowledge resides, imo. If you have come to believe you have it all figured out because you read it on the internet somewhere, that doesn't amount to much more than feeding your technical appetite off the back of cereal boxes.

[Matt27]

NO, i know that dvd is 480i and not 480p which you think it is.

I'm an honest man, you sir are not.People make mistakes it's ok to admit that your wrong.In fact we still hav'nt seen a link from you yet.It's another thing to keep giving these false accusations and think your right and we are wrong.Because that's all your trying to prove in every thread you enter.

Ok so we are not all engineers like you, but at least we can admit to our mistakes.

Your just as bad as JCO.

Enough with you man, i'm going to bed :sleeping:

[strangersonmyflight]

Hey, guess what? If you go into every discussion with the prejudice that person xyz is "mistaken" and brings "false assumptions", then how does that make you an "honest man"??? Make no mistake that it is a prejudice. You have already demonstrated the inability to process information soley by your own devices (wrt HDTV knowledge, at least). If it all comes from "what other people say", then how could it be anything other than prejudice? Had you had zero exposure to anyone else and I told you the things I've outlined in this discussion, you would have nothing other than a big question mark over your head. You literally have not the facilities to tell what from what. That should concern you, but as long as there is a concensus to cower behind, then who cares, right?

[jco]

DVD is 480i/60 because it can do TRUE 480i/60 recording and playback. From this TRUE 480i/60 recording and playback it is possible to create perfect TRUE 480p/30 recording and playback format also.

BUT if DVD was really only a TRUE 480p/30 format, it would be impossible to do TRUE 480i/60
recording and playback because true 480i/60 recording and playback requires independant fields and you wouldnt have 60 independent fields from 480p/30 data, you could only create 30 independent pairs of fields, the fields would have come only in time synced pairs instead of 60 independent timed fields.

The bottom line is a 480i/60 recording system is BETTER than 480p/30 recording system because it is more flexible
and record and output both formats in TRUE FORM. A 480p/30 record/ playback system cannot output both formats in true form so thats why DVD didnt use it. LESS FLEXIBLE. DVD is 480i because the 480i recording and playback system is better than a 480p/30 only system.

[strangersonmyflight]

The truth is...it can do all of those. p24 just happens to fit within its "interlaced plumbing" in such a way that it achieves p24 on the output, anyway. The point I was trying to make earlier (to your post) was, if your requirements are of a refresh rate that is too high, then yeah, DVD would have to fall back to an interlaced format to fit the data. No question or dispute about that. p24 fits fine, and arguably p30 fits fine (I only say arguable because I have no idea really if it actually has the support to take advantage of the hardware to do it)...and naturally i60 fits fine (technically, i48, if you think about it, but that really suffers the middle sibling syndrome, to be sure). Whether or not you want p30 over i60 or vice versa, depends entirely on whether you value detail stability over motion resolution for a specific program material.

DVD was configured the way it was to flexibly handle a range of formats (within its physical capabilities) while providing an easy compatibility route to the prevailing display format of the time- i60. It's not a question of what was better or what offered more options. It was cleverly designed to handle them all.

[jco]

The truth is...it can do all of those. p24 just happens to fit within its "interlaced plumbing" in such a way that it achieves p24 on the output, anyway. The point I was trying to make earlier (to your post) was, if your requirements are of a refresh rate that is too high, then yeah, DVD would have to fall back to an interlaced format to fit the data. No question or dispute about that. p24 fits fine, and arguably p30 fits fine (I only say arguable because I have no idea really if it actually has the support to take advantage of the hardware to do it).

DVD was configured the way it was to flexibly handle a range of formats (within its physical capabilities) while providing an easy compatibility route to the prevailing display formats of the time- i60. It's not a question of what was better or what offered more options. It was cleverly designed to handle them all.
So are you agreeing that is 480i/60 format or not? It is ABLE to do 480i/60 AND 480p/30 because it IS 480i/60! If it was 480p/30 like you were arguing it couldnt DO 480i/60 but it can. That means it is a 480i/60 format which is technically HIGHER than 480p/30 because its capable of 60 independent timed fields, 480p/30 ISNT so its not a 480P/30 format like you were arguing!

Secondly it is NOT really "fine" for P24 like you suggested here and earlier. 480i/72, 480i/48 and 480p/72 and 480p/48 would all be better because then each sourced P24 frame would be displayed the same amount of time. As it is now, the 3/2 pulldown sequence is making every other frame only only 2/3rds the display time as the other frames inbetween. This is not the best way to things, its a compromise made to make P24 sources time out right per second with NTSC 480i/60 but the frame by frame timing is jagged. Even the progressive 480p/60 output of a DVD player has the same problem.

[strangersonmyflight]

I'm agreeing that it is amenable to any of those formats (I hope you aren't implying that by passing p24 through the DVD process, it spontaneously morphs into i60 program material with unique image updates at 1/60 sec). By viewing its capabilities, clearly it isn't any "one" format. What is important is what you are able to achieve at the output. If you can pass a p24 program through it w/o changing the material therein, then it is p24 you are getting. Naturally, you can also pass p30 and i60, as well. How it gets to you is besides the point, unless you are attempting something that does not fall under the original standards. Think of it this way- say you download an application over the internet. Does it matter if it comes to you as a .zip or a .tar or a .sit? If it came in a zip, does that automatically make it a Windows file? As long as you have something to decompress it, the app you extract is still the app you intended to get. It will work exactly the same regardless if it was wrapped in a zip, tar, sit file.

Sure pulldown is not the "ideal" way to do things, but it does work. It's certainly within the capabilities of DVD, so I don't know what your beef is. If you really are worried about "frames not coming in a timely manner", I would submit that film movies just being at a mere 24 fps is a pretty severe limitation to video performance, altogether, rather than worry about how well frames and fields sync up.

[Ratman]

From: http://answers.google.com/answers/threadview?id=301032

A lot of misinformation floating around here. Let's clear it up.

The 525 and 480 designations are exactly the same thing. In both
cases, the video signal is comprised of 525 scanlines, but only 480
contain actual picture information. The other 45, which do not contain
any picture information, are provided for timing reasons.

The native format of DVD is 480i, the operational mode of traditional
televisions. 480i is also the native format of traditional video
cameras. Most DVDs, however, are sourced from film, not video. Film is
natively 24 frames per second, and not interlaced. When a film is made
into a DVD, It is converted to 480i through a technique called "3:2
pulldown":
http://www.zerocut.com/tech/pulldown.html

On a "normal" TV, this is how the DVD would be displayed -- as a 480i
conversion of a 24fps source. To our eyes, this looks perfectly
acceptable.

It is not, however, an accurate representation of the film.
Fortunately, it is not difficult to reconstruct the original film
frames via a process known, not surprisingly, as "reverse 3:2
pulldown". This is why "progressive scan" is a buzzword around DVDs --
applying reverse 3:2 pulldown to a film-sourced DVD yields a
progressive image. (Ideally, it would be displayed at 24 frames per
second, or a multiple such as 48 or 72 frames per second.)

Most HDTVs are capable of performing reverse 3:2 pulldown, and perform
it automatically when film-sourced material is detected. This is one
reason why DVDs usually look better on HDTVs.

Another reason is due to the fact that HDTVs are generally far more
capable display devices than tradtional televsions. HDTVs come in many
different varieties (CRT direct-view, CRT rear projection, DLP, LCD,
LCOS, plasma, etc.), and the details vary considerably between them,
but the general idea is that they have a much higher "fill rate" than
typical televisions--more of the image is illuminated at once, at a
higher refresh rate. This provides a richer, more vivid image with
fewer temporal artifacts, such as flicker. In the CRT world, simply
providing more scan lines provides a more pleasing image, even if
there is no additional detail. This is particularly true for larger
screen sizes.

In addition, most widescreen DVDs will actually show higher resolution
on an HDTV, because of anamorphic encoding. Anamorphic encoding
involves stretching the widescreen content vertically to cover the
entire video frame during the encoding process. This allows the full
resolution of the DVD format to be used. All DVD players are capable
of the inverse transformation -- squashing the picture vertically to
the correct aspect ratio for display on a normal 4:3 aspect ratio
televsion (and losing some detail in the process). A properly
configured HDTV setup will perform this transformation such that the
full resolution encoded on the DVD can be used.

If the 480 scanlines of data are "expanded" to 720 or 1080, it is
performed in exactly the same manner as resizing an image on your
computer -- no additional information is added. The increase in image
quality is not a direct result of the image being resized, but rather
because display devices typically produce a more pleasing picture with
more scanlines.

From: http://www.projectorcentral.com/480i_vs_480p.htm

Why? A DVD is encoded in digital component interlaced format. Frames must be assembled into sequential progressive scan format within the DVD player for it to output a 480p signal. This deinterlacing happens in the digital domain before the information is converted to analog for transmission. So in theory a good deinterlacer in the DVD player has the best chance of assembling the cleanest signal.

[raff]

Ah, nice to wake up to this drama!


Strangers, since you don't know and have accused me of "hiding behind the mods" let me level the playing field for you a little. I hide behind no one. I am a highly paid, highly respected, Data COM Engineer. I have been an Amateur Radio operator since 1988. I've owned a PC since the Commodore VIC20. In short, a man on my own legs.

Since I find it futile to post any more evidence of why DVD's are 480i, you can call me insecure if you like. What I know is that no matter how many volumes of knowledge we drop on you, you'll read and take only what you want and be done with it.

Do you not find it a little odd, that no one has come to your defense? Do you really have such a superiority complex that you can be right and thousands wrong?

Not to make judgments, but something tells me you're an out of work actor, living outside of LA, whose only experience with film is from the AVID system in two year college.

[raff]

On more thing...

Learn how the telecine operates, and you'll have the answer to this thread.

[strangersonmyflight]

You are not insecure, but you feel compelled to make an entirely new post to attach a derogative, overused charicature upon me??? Talk about doublespeak. Maybe you should add "cocky" to your list. Your background, real or alleged, is irrelevant. One only needs to observe your posting behavior. Being that your characterization was so way off, that would make you wrong on 2 counts now. Not batting so well, eh? Still confident about your interpretive abilities?

Did this part of Ratman's quote slip by you, or are you just glad that he posted something:

"Fortunately, it is not difficult to reconstruct the original film
frames via a process known, not surprisingly, as "reverse 3:2
pulldown". This is why "progressive scan" is a buzzword around DVDs --
applying reverse 3:2 pulldown to a film-sourced DVD yields a
progressive image."

It yields a progressive image. That's all you need to consider. Whether it goes through an interlaced, tri-laced, quad-laced, or shoelaced mechanism is largely irrelevant, other than bragging rights, perhaps. If I gave you 5-ones and a 5 dollar bill, in exchange for a $10 bill, what exactly is your motive in complaining that I did not give you fair change? Does it really matter if you get 5-ones + $5 bill or 10-ones or just a plain $10 bill in return? You still got 10 bucks, ffs! Now if you gave me a $10 bill, and I only gave you back every other dollar (for a total of $5), surely, you have a solid case to whine...

Now if every single DVD ever made came from videotape source, you would most certainly be correct. Unfortunately, this is not the case. That's why I have been very specific all along to indicate my words are in reference to movie DVDs. Nevertheless, progressive is progressive. It doesn't matter if it came from ota HD broadcast or was reconstructed from computer punch cards (as unlikely a scenario that may be).

[mjones73]

DVD's are formatted at 480i, the frames are split and stored as two fields of odd and even scan lines on the DVD regardless if the source is film or videotape, that's all there is to it. Why you can't comprehend that I don't know.

I'll say it again, if we are wrong, show us some proof other then your personal thoughts on the matter or some more insults for the other members here yet again.

[raff]

One only needs to observe your posting behavior.

LOL!!! Please enlighten me on this one!

My posting behavior is to post facts and try to help people. Yours is to argue and disagree, no matter the subject.

I've sited an ISF technician as a resource.

You have been asked to cite your sources, but have dodged that request at every turn.

Facts are facts...

DVD's are formatted 480i

No one, other than you of course, has refuted that. Why?????? Please tell me why!

[raff]

Citing one more resource...

Taken from a telecine lab's info.

Digital Video programs produced for either NTSC or PAL resolution must be in interlaced format.

[mjones73]

Sorry, deleted my post there, I'll put it back

Nor after repeated requested for backing your claims have you done anything but repeat your own interpretation of the facts. Show us some hard proof strangers or spare us the BS.

[57U]

I can only assume that this "dialogue without proof" somehow amuses Strangers. There are several other posters that are on my "ignore" list. Strangers is now added to that list. I urge others to do the same.

[raff]

Probably the best bet 57U, thanks for the idea!

[strangersonmyflight]

DVD's are formatted at 480i, the frames are split and stored as two fields of odd and even scan lines on the DVD regardless if the source is film or videotape, that's all there is to it. Why you can't comprehend that I don't know.

You seem to have forgotten the simple question/answer posed earlier (the one you consistently dodged to answer directly, as I remember).

field #1 @ t=1/24 sec
field #2 @ t=2/24 sec
field #3 @ t=3/24 sec
.
.
.

Is this how movie DVD frames are stored? Yes or no? If not, then it isn't exactly interlaced in the same manner that interlaced video is, is it? If it is a trivial process to reconstruct progressive frames from the way they are stored on a movie DVD, then that obviously begs some distinction (in the same vein as it doesn't matter if you get 2-$5 bills or 10-singles, you can still convert it seamlessly for a $10 bill). Unless you are implying that the way progressive frames are derived for movie DVD's is not a "pure" enough form to be considered progressive? Just say that then. Also be sure to note that by saying so, this puts a majority of progressive presentations of movies on HD channels in similar jeopardy... They can't be "true" progressive, either, if they are using that "nasty" pulldown to match to typical 60p framerates... Uh-oh! ...or better yet, why don't you go on record and say that there is no difference in the image whether you watch the 480i output or 480p output of a DVD player with a movie DVD? It's hopelessly interlaced, right? Why even bother with a progressive scan DVD player? Let the HDTV do the conversion...it's all interlaced crap, anyway, right?

The final coup de grat is where you click the ignore button, right? No wonder "everyone" agrees with you- you eliminate all who choose not to, anyway. :rofl2: That's the funniest part of all of this!

[raff]

Also be sure to note that by saying so, this puts a majority of progressive presentations of movies on HD channels in similar jeopardy... They can't be "true" progressive, either, if they are using that "nasty" pulldown to match to typical 60p framerates... Uh-oh!


Oh lord!
HD Broadcasters don't source from DVD, and except for ABC, the HD channels are 1080i. They source from a broadcast tape, mastered in either 1080i or 720P.

[mjones73]

Quote:
Originally Posted by mjones73
Yes technically the data for the full frame is on the DVD,...


That is all you need to know. You have the full image in the data, hence it is a trivial step to then become "progressive".

By making this statement, you have then answered my "simple question". Since you are evasive to give a direct answer, I will give it for you. The answer is "no", the images in a movie DVD's are not encoded in such a manner. If they were, then there would be some substance to "most DVDs" being interlaced. You should also note that your original quote of "proof" on the subject also cited that there is no duplicated frames involved. Hence it is doubtful that data is being spooled off the disc in 1/48 sec chunks. That would result in...duplicated frames and a lot of wasted space. You achieve the matching of frame rates via electronic buffers and pulldown at the very end of the chain, NOT on the encoding of the disc."

The article I posted stated the data is stored in fields and flags are added to tell the MPEG decoded to repeat certain fields to achive the proper frame rate, it does that so you don't need to record repeated frames on the DVD to save space. If it has the ability to repeat fields, then guess what, it's reading it at 1/48 second chunks to get the individual fields.

Try re-reading the article I posted... better yet, let me requote the passage for you so you don't miss it..

MPEG-2 and DVD

So the basis of this technique is to restore proper timing by generating redundant image information from four film frames within every five NTSC video frames. But wouldn't it be silly to waste 20% of the storage space on every DVD with duplicate picture data?Fortunately the MPEG-2 standard nicely avoids this inefficiency. When a film source is encoded for presentation on DVD, it is stored at 24 frames per second; each video frame contains all the picture information from each film frame. There is no redundancy or duplication. Such a transfer is written to DVD as 720-pixel wide by 480-pixel high interlaced frames (where each frame contains two 720 by 240 fields), and there are only 24 frames for each second of film. This is known as 480i24. On each DVD encoded from a film source, a flag is inserted within the MPEG-2 data stream that instructs the player to repeat certain fields to reconstruct the 29.97 frame per second interlaced video. The player obliges by performing the 3:2 pulldown in real-time, continually creating interlaced frame sequences just like the one shown in the above figure, "The Telecine 3:2 Pulldown Process for NTSC Video."This capability enables the player to produce video compatible with conventional displays that were designed based on the NTSC video standard.(As we shall see later, progressive scan DVD players take a different approach.)

The Downside

While the 3:2 pulldown process restores the proper speed of the film on video, it generates some unpleasant problems. Two sequential video frames within every five video frame sequence contain images from different film frames.

Now wouldn't the player need to be able to read the individual fields and reconstruct them to be able to have two frames out of every five with data from different frames in them? If the data was stored on the DVD in a progressive format, this process would be quite messy if the player had to break the frames into two fields itself, the player doesn't need to do that though because the data is already stored in an interlaced format with the frames split into two fields.

[strangersonmyflight]

Still gonna use pulldown to get the framerates to match. Broadcast tape, for all you know. It could just as easily be the interlaced copy they use on their SD broadcasts, for all you know.

When are you gonna hit the ignore button to give all of us a rest???

[mjones73]

When are you going to admit your wrong and give it a rest?

I've come to the same conclusion as 57U that it amuses you to see us argue with you regardless if your right or wrong.

[BadCamper]

By making this statement, you have then answered my "simple question". Since you are evasive to give a direct answer, I will give it for you.



Regardless of where I stand in this argument, I would like to say the following:

Strangersonmyflight - you're like a journalist. You hear the whole story, and pull out the bits and pieces that you think everybody else should know. Try being a bit more objective.

You completely pulled that phrase above out of context: Yes technically the data for the full frame is on the DVD,it's still stored in two interlaced seperate fields though, not as one full frame therefore the DVD is interlaced, how hard is that to understand?

[57U]

Oh lord!
HD Broadcasters don't source from DVD, and except for ABC, the HD channels are 1080i. They source from a broadcast tape, mastered in either 1080i or 720P.
1080i and 720P are broadcast formats.

Althought 1080i is sometimes used for masters (tape) (as is 480i widescreen and 480i standard). The typical HD master is 1080/24P (tape).

[strangersonmyflight]

I see your selective reading causes you to keep missing this part:

"When a film source is encoded for presentation on DVD, it is stored at 24 frames per second; each video frame contains all the picture information from each film frame. There is no redundancy or duplication."

Does it matter if the information arrives in 2 fields, instead of all at once? All information is there to generate a full frame. Maybe that's not good enough from a staunch purist view, but functionally it is every bit as good as a genuine full frame strategy (if one were to exist for DVD). Again, this is splitting hairs over the difference between 10-$1 bills and a $10 bill. What matters is what you have in the end- $10 worth of money.

[raff]

Still gonna use pulldown to get the framerates to match. Broadcast tape, for all you know. It could just as easily be the interlaced copy they use on their SD broadcasts, for all you know.



Huh???
HD channels do not source from DVD, though you have admitted that they are interlaced!!! PROGRESS!!!!!

[strangersonmyflight]

That was your assertion. I never made the claim they sourced from DVD. Nice try to derail, though.

On a sidenote, that puts upconverted SD material that appears on an HD channel in a funny place. If it came from interlaced video, does that then mean the HD channel is not true progressive? Hmmm...so many ways to apply this mjones/raff logic...

[mjones73]

I see your selective reading causes you to keep missing this part:



Does it matter if the information arrives in 2 fields, instead of all at once? All information is there to generate a full frame. Maybe that's not good enough from a staunch purist view, but functionally it is every bit as good as a genuine full frame strategy (if one were to exist for DVD). Again, this is splitting hairs over the difference between 10-$1 bills and a $10 bill. What matters is what you have in the end- $10 worth of money.

Yes, it's the difference between the DVD being interlaced or progressive, the frames are always stored as two fields regardless of the original format of the program. In your past statements you've said it could be stored either way based on the source material being film or video and that's incorrect just as some DVD's are 480p is incorrect.

[mjones73]

And yet again, you've yet to show any proof other then your interpretation of the facts. I'm done amusing you with this argument, you'll be a welcome addition on my ignore list also.

[Razor8]

Perhaps you haven't understood our requests. Please provide evidence to support you claims. How many times have you been asked to do that? Several just in case you forgot. And have you? No. Why? Perhaps you can't find any information that supports your views????? Razor

[HookemHorns]

Strangers will never admit defeat....There is enough info. on this thread for any poor sap that happens to stumble across it to make up his/hers own conclusion of 480i or 480p. IMHO this thread should just be layed to rest already.

My vote goes to 480i.......but then again, I am just the mods lap dog.

[raff]

IMHO this thread should just be layed to rest already.




I concur.

[Matt27]

That's right strangers we are all stupid and your allways right.Hell, maybe you should work this site since judging by yuor posts you are up 24/7.

It takes a man to admit he's wrong, and that you are not in my book.As well as every one elses.I would'nt be surprised if you were an unemployed actor, because you sure are doing a good job at it.

ONCE AGAIN!!! Please show us proof to back up your answers that way you can officially all call us idiots, and we would more than happily put you on our ignore list.

Good day to you sir!

[Razor8]

Strangers, I think what you are experiencing is an ID 10 T error. The following information is provided by Robert Silva who has experience in electronic sales, video production, film colorization and computer animation. He also has a degree from SDSU as well as a technical television production certificate.

All DVDs are recorded in the 480i standard. When a DVD player plays a DVD, it is the progressive scan processors and line doublers used in the playback path that can determine how the 480i video recorded on the DVD is eventually displayed on a television or projection screen.

The reason that DVDs are ALL recorded in the 480i standard is so that they can be read by all DVD players and be shown on a standard analog television. EVEN IF YOU COULD RECORD A DVD IN 480P OR HIGHER THE DVD WOULD NOT BE PLAYABLE ON A STANDARD DVD PLAYER SINCE DVD PLAYERS CAN ONLY READ 480I OFF THE DISC ITSELF.

[Ratman]

Did this part of Ratman's quote slip by you, or are you just glad that he posted something:

"Fortunately, it is not difficult to reconstruct the original film
frames via a process known, not surprisingly, as "reverse 3:2
pulldown". This is why "progressive scan" is a buzzword around DVDs --
applying reverse 3:2 pulldown to a film-sourced DVD yields a
progressive image."

But... you missed the key point (in the material I provided, re-posted below for your convenience) prior to your selective rebuttle (re-posted above. And take note of the term "reconstruct").

Re-read both closely:

The native format of DVD is 480i, the operational mode of traditional
televisions. 480i is also the native format of traditional video
cameras. Most DVDs, however, are sourced from film, not video. Film is
natively 24 frames per second, and not interlaced. When a film is made
into a DVD, It is converted to 480i through a technique called "3:2
pulldown"

To make this easier...
to convert from film (24p) to DVD (NTSC 480i/30) 3:2 pulldown is applied.

to convert from 480i/30 to 480p/60, 'reverse' 3:2 pulldown is applied.

[strangersonmyflight]

Yes, yes, yes, it is well known the data is formatted to provide easy interlaced output. What all of you seem vehemently opposed to recognize is that all the data to reconstruct the original full frame is also conveniently embedded within the format for easy progressive output. There is no fancy line doubling, interpolation, or approximation needed or involved. All the data is there to yield the original full frame. In that respect, it is every bit as much "progressive" as if the program could be stored in solid frames on some "hypothetical progressive format DVD". From the very start, my goal was to bring about the understanding that there is more going on in there than just a simple interlaced program. If it were the case of just a plain jane interlace strategy, you could not create the original progressive output (a fascimile- surely, the original- no). Maybe it was just a happy coincidence in the way things turned out. Maybe it was a very clever implementation to optimally serve both interlaced and progressive users. Nevertheless, it exists. It cannot be dismissed. Perhaps this calls upon the ability to think beyond what is written in stone before you, rather than stay strictly within what has been committed to a FAQ. Some people can do this, and others display extreme anxiety when called upon to do so.

As for matt, your remarks really mean very little coming from you. You cannot behave in the immature way you have here, and then turn around to look down your nose at me. Things just don't work that way. You and Raff have demonstrated yourself as shameless moderator lapdogs, so really, you have the lowest status of any "kinds" of people that exist at these forums (even me). To make like you can shake a finger at me and believe it means something is utterly ridiculous. It's one thing to contribute to a discussion. It's another to consistently fire off inflammatory barbs and attacks at another, fully under the cover of moderator liberty. If you want to discuss the topic, stick to the subject. As soon as you stoop to casting interpretations of things like someone's employment status and other imaginary cliche stereotypes, you have automatically dredged to a level far below anyone else here who simply read and posted nothing (the idea being, you would have been better off just not posting anything). It doesn't matter if the recipient of your post is right or very wrong. The behavior is inappropriate (but apparently fully sanctioned by the mods when it suits them). Neither you or the mods should be looked fondly of for participating in or allowing the participation of such poor behavior. That part is indisputable by any reasonable minded person.

On the count of providing my own information...is this really necessary? The information that others brought here was fully adequate to give support to idea I was trying to convey. If that leap was possible, why not run with it? I could post all kinds of quotes, too. What's gonna happen? We just get into a dispute over, "I don't like your sources." "Oh, yeah? Well I don't like your sources." So what does that accomplish? Nothing. There is no silver bullet. I worked with the very same information that you brought to bear. There's very little to complain about for a strategy as that.

Were you expecting me to come up with some quote declaring that movie DVD's are progressive? Of course, something like that doesn't exist! Does that mean there is nothing to my claim? There is more going on in a movie DVD than a simple interlaced program. That's the leap many people have had profound trouble coming to grips with, instead responding with aggression, personal attacks, and arrogant dismissal (things that simply do not belong in a reasoned discussion). Instead of simply saying, "I cannot make the leap you are suggesting. I do not agree with you", we get all sorts of gradeschool level, reactive static from otherwise presumably full-grown adults. Does it matter how esteemed your personal background is when you degrade to this on a faceless discussion forum the instant you encounter adversity? There's no other way to interpret this than an utterly pathetic lack of maturity. You don't have to be of eccentric mind to find this absolutely truthful.

[Ratman]

Yes, yes, yes, it is well known the data is formatted to provide easy interlaced output.....

Were you expecting me to come up with some quote declaring that movie DVD's are progressive? Of course, something like that doesn't exist!


So... you agree that all DVD's are encoded at 480i.

[mjones73]

"Yes, yes, yes, it is well known the data is formatted to provide easy interlaced output.....

Were you expecting me to come up with some quote declaring that movie DVD's are progressive? Of course, something like that doesn't exist!"

Hmm, doesn't that statement contradict the original claim made that started this whole argument? :rolleyes:

[Razor8]

Matt, I believe that was the point I made in a post which has been removed. Strangers twisted this whole thread so much that he lost track of his own statement in the very first post. Then contradicted himself. It may be ok with you for Strangers to come on here and insult everyone but its not ok with me. Especially when what he is saying is wrong. I won't allow myself to be walked on and I suggest others do the same. We are nobody's doormat strangers. Razor

[mjones73]

57U made the best suggestion, add him to your ignore list.

[jco]

I think what you guys are all overlooking is the fact that 480i/60 DVDs are not all made from progressive sources. If the original source material was RECORDED at 480i/60 then DVD can be mastered and played back with that 480i/60 material
simply and accurately with almost no pre or post processing. In other words the bit stream
is alternating fields so the video can almost be created almost "LIVE" right off the disc datastream. Progressive true 480/p30 or lower can be created at the output ONLY with
some buffers, delays, and manipulation. This makes DVD a 480i format. If DVD had progressive datastreams and interlaced outputs were created with buffers and manipulation then it would be a Progressive format. But thats not the way it is. Datastream is interlaced data. I think this is the only way you could classify
a serial recording format like DVD and it would have to be classifed as INTERLACED,
not progressive even if progressive output can be created with buffers and manipulation. Otherwise what else could you use do classify them?? Seems to me
the output format that requires the least manipulation of the disc datastream is
how you classify the format's "native" format. DVD is INTERLACED native format for this SIMPLE reason alone although I could add more reasons if I wanted to but they arent necessary.....

[soze]

jeez, can't we all get along? not sure what's happening with this post...

I may or not agree with Ratman..but everyone knows DVDs are 480i...there's no argument.....i mean....really

please make peace with yourself...

[jco]

There's no argument? Read the thread, there WAS an argument and I think I pretty much just settled it in an incredibly simple manner not put forth until now. Of course it all looks so silly now but to say there wasnt an argument over it is not a very accurate statement, if there wasnt this wouldnt be post #89 in the thread...

[strangersonmyflight]

Actually it was delineated far before any of that (sorry, jco). Unless you find it encoded like this, then the term "interlaced" is far too simple a designation to describe how movie DVD's are prepared:

field #1 @ t=1/24 sec
field #2 @ t=2/24 sec
field #3 @ t=3/24 sec
.
.
.

Such as the above, would be, without a doubt, a pure interlaced setup. Being that movie DVD's are NOT done this way, it is arguable that "simply interlaced" is/isn't truly accurate. Using a more critical view, you find that it can be just as "progressive" as it is "interlaced". All you need to do is look beyond the buzzwords and take note of the dynamics of the system.

Btw, jco, you will be surprised to find "buffers" exist in all sorts of places in a digital-based system (but maybe your criteria would have been more happy in the laserdisc days). Literally, you cannot escape them- it's what allows stuff to "work". If buffers had anything to do with what you call something, you might as well not call DVDs interlaced OR progressive. They couldn't be either, because information is passed serially, bit-by-bit. Hence "everything" would be "bitstream", no and's, if's, or but's. Being that the prevailing logic here is that once something goes through some "state", it can never be reconstructed into any "states" it may have existed before (which is laughably untrue, of course, but there's mods for ya). Hence, everything is "bitstream", and can never, ever be returned to any supposed interlaced or progressive state...

Now for those of us that live in the "real world", we are at least open to the idea that data is data. It doesn't matter if it has to pass through some point in the signal chain as bit-by-bit, line-by-line, or even field-by-field. If the required data is present within the given data set to reconstruct (note- not the same as "simulate" or "synthesize") the original data format, then it is valid to give it reference by the original data format. Now this may offend certain person's sensibilities here, but dems the facts. Maybe the bigger idea they are missing is aren't we lucky somebody went ahead to take advantage of this strategy when they were cobbling together how DVD's will work? (Otherwise, movies DVD's would never have had a way for true progressive output, period.)

[Ratman]

:rofl2:
...............

[raff]

:headscrat

LOL!! My God, do I have a headache!!!

:argue2:

[jco]

Actually it was delineated far before any of that (sorry, jco). Unless you find it encoded like this, then the term "interlaced" is far too simple a designation to describe how movie DVD's are prepared:

field #1 @ t=1/24 sec
field #2 @ t=2/24 sec
field #3 @ t=3/24 sec
.
.
.

Such as the above, would be, without a doubt, a pure interlaced setup. Being that movie DVD's are NOT done this way, it is arguable that "simply interlaced" is/isn't truly accurate. Using a more critical view, you find that it can be just as "progressive" as it is "interlaced". All you need to do is look beyond the buzzwords and take note of the dynamics of the system.

Btw, jco, you will be surprised to find "buffers" exist in all sorts of places in a digital-based system (but maybe your criteria would have been more happy in the laserdisc days). Literally, you cannot escape them- it's what allows stuff to "work". If buffers had anything to do with what you call something, you might as well not call DVDs interlaced OR progressive. They couldn't be either, because information is passed serially, bit-by-bit. Hence "everything" would be "bitstream", no and's, if's, or but's. Being that the prevailing logic here is that once something goes through some "state", it can never be reconstructed into any "states" it may have existed before (which is laughably untrue, of course, but there's mods for ya). Hence, everything is "bitstream", and can never, ever be returned to any supposed interlaced or progressive state...

Now for those of us that live in the "real world", we are at least open to the idea that data is data. It doesn't matter if it has to pass through some point in the signal chain as bit-by-bit, line-by-line, or even field-by-field. If the required data is present within the given data set to reconstruct (note- not the same as "simulate" or "synthesize") the original data format, then it is valid to give it reference by the original data format. Now this may offend certain person's sensibilities here, but dems the facts. Maybe the bigger idea they are missing is aren't we lucky somebody went ahead to take advantage of this strategy when they were cobbling together how DVD's will work? (Otherwise, movies DVD's would never have had a way for true progressive output, period.)

The only thing that surprises me is how thick headed you are when it
comes to something so simple. Either you really dont understand why
you are wrong or you know you are wrong and you are trying to save
face by arguing even after its clear you are wrong. That in my opinion
only makes you look worse so its counterproductive. Either way either
not understanding or trying to talk your way out of your incorrect notion
is bad....

I think you need to READ what I said and get over the fact that you are wrong. I never said there wasnt ANY pre and post processing in DVD encoding and playback, I said ALMOST none. And the very simple fact is that INTERLACED video into and out of a DVD HAS THE LEAST amount of pre and post processing which makes DVD 480i/60 INTERLACED NATIVE FORMAT. Yes other formats are possible but they require EXTRA processing at encoding and at decoding that INTERLACED input and outputs DONT. If you cant understand that you are few cards short of a full deck. The BITSTREAM SEQUENCE off the disc is set up for INTERLACED outputs with minimal processing, THATS WHAT MAKES IT INTERLACED NATIVE FORMAT. If it was setup for progressive minimal processing it would be a progressive native format, BUT IT ISNT. Duh. You are really slipping into the realm of incredibility
on this one dude.

As far as the real world goes, DVD Data isnt just data, it comes off the disc as a serial data stream. If the data is sequenced on the disc such that all the odd pixels ( odd field) come off and then all the even pixels come off (even field) then the DVD has been formatted (data sequenced) for interlaced playback with the LEAST AMOUNT of post processing (notice I did not say none, I said LEAST amount) and THATS HOW DVD WORKS. If you want progressive playback you need to do extra processing to convert it to progressive, thats a CONVERSION, thats not the native format. Thats what makes DVD 480i (interlaced) native, not progressive native. Just because you can manipulate the interlaced data into progressive data doesnt mean the DVD format is progressive NATIVE. It isnt and you are really hurting your credibility by continuing to insist that DVDs arent really a 480i native format when they are and it has been very clearly pointed out to you how and why in VERY SIMPLE terms. The simple fact is that DVD can do interlaced EASIER than progressive, so that makes it INTERLACED. They could have very well designed it to do progressive EASIER than interlaced, BUT THEY DIDNT. Thats the distinction you dont seem to understand or wont admit to being the fact but it IS.

Furthermore, I will point out to you that DVD was designed in the early to mid 1990's and at that time there was essentially no such thing as Progressive Display consumer TVs, almost everything at that time was NTSC 480i display
so IT MADE SENSE to choose DVD as 480i NATIVE because it meant that the DVD players were far simpler AND CHEAPER if the DVD format was 480i native. If they had made DVD format 480P native, the cost of the players would have been extremely high at the time because of all the extra hardware and processing that would have been needed to convert the progressive data
to interlaced. THEY DIDNT NEED IT because they CHOSE DVD to be 480i native. Welcome to the REAL "Real world"!

[Razor8]

Much information has been posted from reliable sources but he either doesn't understand what he is reading or he doesn't understand what can be gained by admitting one is wrong. Don't change the subject. 480i or 480p? Make your choice. Razor

[Matt27]

I think he does'nt want to beleive what we say, but only his own interpertation.

LOL Ratman you crack me up!!!

DVD is 480i period!!!

what ever you come up with strangers is ok and all, but it does'nt change the fact that dvd is 480i.your facts are very good, but i know dvd is 480i, no need to convince us of something it isnt.

Thank you,

Matt~

[sillygoose]

Wow, I don't check the board in a while and I miss all the fun. It sounds like strangers doesn't like to call it interlaced unless the fields actually contain data from different frames. Not that it really isn't interlaced but apparently if you can buffer up the interlaced fields to get a real frame instead of a mangle of two different frames then strangers thinks it should be called progressive. My question is when film is encoded to DVD is any frame to frame interpolation performed to create the intermediate fields by any encoder that anyone knows of? I think the answer is no it just does the reverse 3:2 pulldown (unless I got that backwards) and splits the frames into two fields.

[mjones73]

It splits it into two fields and flags the data so that the DVD player's decoder knows which fields to repeat when decoding the information to achieve the proper frame rate. The site I linked at the beginning has a good explanation of it.