Results 1 to 4 of 4
  1. #1
    ryk is offline
    Forum Regular
    Join Date
    Oct 2005

    Questions on DVD player functions and format

    What is the function when DVD manufacturers say some of their players upconvert to HD DVD??
    What is the reslution of presnt DVD??
    What does the progressive scan do???
    What is the advantage to the DVD upconverting and the present progressive scan function?
    Is it worth getting a HD DVD player..I firgure the prices will reduce to present price points once everyone gets the techonolgy into their machines!!!

    I know these are a lot of questions, but it's better than not knowing and making a mistake buying too soon or getting something I really don't need just yet!
    Thanks for any and all responses!!
    "Nothing fades as fast as the future
    and nothing clings like the past"
    - Peter Gabriel

  2. #2
    Forum Regular
    Join Date
    Dec 2006
    the first question is the trickiest.

    There are quite a few terms being bandied around on the market which sound similar and mean different things at the moment. the two pure terms to which they refer are "Video Conversion" and "Video Upscaling"

    Video conversion means various types of video are converted from their true native types in order to be spit out of one singular output type on the rear of the device, EG: composite, S-video being "Converted" to be displayed out of the component video or HDMI output of the unit, thus enabling "seamless switching" between sources.

    Video Upscaling means that the native SD 480i resolution coming form oh, say, your VCR is processed by the machines chipset, filler lines of resolution are added, color is processed to the fill lines, and the output thus becomes a regurgitated 720p or something along those lines.

    The confusion comes when manufacturers start using terms like "Up Conversion" In this case, the item, a dvd player, likley converts the native 480p resolution of the DVD up to a 720p or possibly even a 1080i, although 1080i is doubtfull given the expense of the video chipset that would be required to produce that level of fill analyzation. Most likley its a 720p output.

    Which leads to your next question.
    The current output format for DVD is 480p.

    You have probably noticed the little letters following these resolutions... I and P..

    Interlaced and Progressive. Both of these refer to the method in which the video is fed to the display unit.

    Interlaced is Ye olde way of sending video that has been used over the years, in which a portion of the lines of resolution are sent to the TV a section of the screen at a time. This process can clearly be seen when a monitor is videotaped, you see the porcess happening in stop frame motion because the frame rate of the 2 devices are not synchronized. So you see what appears to be a rolling line of modulation flipping horizontaly down the screen that is not visible to your eye when you look directly at the monitor.

    Progressive on the other hand sends the entire screen, in a framerate burst. the overall picture quality is better, and the nuances in motion that can be lost to parts of your screen filling in momentary differential is negated.

    Every rose has it's thorn.

    The downside to progressive is that cavemen didn't have progressive scan capable equipment... (sorry gramps)... So when viewing old movies that havent been put through a digital remastering sequence the interlaced original image leaves quite a bit up to the fill processors imagination. thus a select portion of each frame you view was never written, filmed, signed off on, or thought up by the bloke who made the flick. Video Upscaling takes this a step further.

    Personaly im not a prude, but at the same time it is troubling to me that up to 20% of the dress Scarlet O'Hara is wearing was "thunk up" by my dvd's processor. Also makes you question what their face would look like with 20% fewer imaginary lines...

    But this is a temporary problem at best, right now the dvd marketing trolls are all creaping around thier caves digitally re-mastering the classics using progressive compatible equipment, and within 20 years or so, the fill ratio gizmo in your unit will be a very bored little creation.

    Is it worth it...

    The real question is is it worth it to YOU.

    If you have someone willing to pay you one million dollars for a paper clip, then the paper clip IS worth one million dollars.
    This statement shows the inherent lie built into a freemarket economy, im not downing it, mind you, but it IS built on the supposition that an item is actually WORTH what someone will pay for it.

    Physically speaking, they pay about 10% more to make a HD-DVD widget than a conventional DVD widget. the price they are charging for them, as with all new item releases, is a hurried attempt to recoup R&D costs spent on the new technology. If you are the type of person who absolutely HAS to have the latest, greatest wonderbread, then this is for you.

    You may lament your decision to buy early for awhile however, when you have to show your latest device off with a copy of PBS' Quilts of the Ottoman Empire... because that was the only HD-DVD you could find to buy. PBS is usually first out with everything, must be nice to run a company that has a limitless budget and doesn't have to show a profit... So that is a consideration.

  3. #3
    Forum Regular N. Abstentia's Avatar
    Join Date
    Apr 2004
    Next time you try to answer somebody's question at least spend a little time on the response.

    Just kidding..nice job

  4. #4
    Forum Regular edtyct's Avatar
    Join Date
    Jun 2002
    One thing, though, in a terrific and entertaining answer. So far as film is concerned, progressive scanning to 480p per se doesn't insert any new information on your TV screen (at least until it's scaled, as it is on nearly every fixed-pixel display on the market). The technique of 2:3 pulldown, which is responsible for converting the fundamental movie frame rate of 24fps to the NTSC standard 30fps, interlaced to 60 fields (as Daedulus so accurately described), neither adds nor subtracts information from the original data. It simply shuffles the information in an orderly way to allow its reconstruction on hardware with a different refresh rate.

    When progressive scanning enacts reverse 2:3 pulldown on interlaced video (which is the native form of DVD material, unless the player changes 480i to 480p), thus recombining the fields into their original frames but repeating them, again, in a cadence compatible with the usual 60Hz refresh rate, theoretically no loss of content should occur. However, the processing device (be it a TV, a DVD player, or a dedicated unit) is responsible for picking up the cadence quickly and accurately to ensure that the original frames are assembled correctly. If so, the only remaining "problem" is an inevitable artifact called "judder," a kind of choppiness that results from the uneven (2:3) cadence. If our displays were capable of refresh rates at multiples of 24fps, this judder would virtually disappear. By the way, 24fps, if it were possible, would be too slow for home video; you'd see flicker--hence, the need for multiples of this rate. Currently, only a Pioneer plasma or two and a Sony LCoS projector are capable of inputting film signals at multiples of 24fps, and even film projectors cheat.

    Video, as opposed to film, is a different story. Since, unlike film, video starts out as an interlaced format, it does not convert to progressive scanning through a mere reassembling (with a little mathematical hocus pocus) of original frames. It requires subjection to cunning algoritms to create one frame out of successive independent fields, such as motion-adaptive processing. Faroudja made its name this way, but other companies have followed suit. The best processing today is really good, and the bread and butter processing ain't all that bad. After all of this processing occurs, the telltale signs, to one extent or another, are jagged edges, combing, line twitter, and a few other goodies. With a lot of hard work, good video processing can disguise the fact that some of the finished product was composed, to some extent, ex nihilo, which might be construed as a little like divine intervention (creating something out of nothing).

    If you add the trials and tribulations of scaling (blowing up a 480i/p image into a 720p, 1080i, or 1080p image), you can see how the once glorious DVD picture could turn into, on a big modern digital display, mush. It's a testament to ingenuity that, more often than not, it doesn't.
    What was the question? Oh yeah, although I sympathize with those who don't want to throw their money down the drain on a failed hi def format during the war between HD DVD and Blu-ray, some of the risk can be mitigated. Toshiba, in an effort to establish a beachhead, is losing as much as $200 per player with their pricing. You can find a hi def DVD player for $350 to $400 if so inclined. Not only do these players show films in pristine hi def (in many cases), with advanced audio, they also make a good showing with legacy DVDs. My Toshiba HD A1 appears to be as capable a player of standard DVDs as my Sony ES, and it scales them to 1080i on my 1080p display with nary a hitch. Since Netflix carries both HD DVD and Blu-ray disks, no one needs to "waste" any money on movies that might eventually become obsolete (though I'm beginning to doubt whether that will happen any time soon). If you love HD and want to jump on the hi def bandwagon even at this early-adopter stage, you don't necessarily have to shoot yourself in the foot. In fact, you could spend a lot more money on a standard DVD player and get only marginally better performance on standard DVDs and nothing like hi def DVD. Food for thought, anyway.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts