PAL DVD on USA player?
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From: Dave Plowman (News) on 1 Apr 2010 04:29 In article <81ieciFu3eU1(a)mid.individual.net>, Phil Allison <phil_a(a)tpg.com.au> wrote: > > There is no such thing as PAL data. > ** More bollocks. > The data is formatted as either PAL or NTSC on the disk. Phased Alternate Line? How interesting. -- *What do little birdies see when they get knocked unconscious? * Dave Plowman dave(a)davenoise.co.uk London SW To e-mail, change noise into sound.
From: Dave Plowman (News) on 1 Apr 2010 04:28 In article <voq7r5thoc581eq55bcalu92qo6kte59ju(a)4ax.com>, mm <NOPSAMmm2005(a)bigfoot.com> wrote: > DVD recorder/players sold in the USA won't play PAL DVDs, will they? There's no such thing as a PAL DVD - or NTSC, for that matter. They are just called that to identify the region they are 'allowed' for. -- *Just remember...if the world didn't suck, we'd all fall off* Dave Plowman dave(a)davenoise.co.uk London SW To e-mail, change noise into sound.
From: Geoffrey S. Mendelson on 1 Apr 2010 05:09 Dave Plowman (News) wrote: > >> The data is formatted as either PAL or NTSC on the disk. > > Phased Alternate Line? How interesting. > The term PAL in reference to the DVD refers to the picture encoded, originally a PAL (or SECAM) 50 fields per second interlaced picture with 1:4 chroma data. The encoded signal is 25 frames per second, and still has the same chroma information, but the chroma is stored separately in the data stream, the way it was on a separate track on VHS/BETA video tape. It's up to the player to figure out how to play it. To be played on a standard TV, the frames have to be cut down to 625 lines, and split into two fields before being played on a PAL TV. The chroma information has to be phase encoded and added as a color subcarier. Note that the chroma information is the same with NTSC or PAL signals, the difference is how it is added to the signal. NTSC signals added the color at a subcarrier frequency of 3.57 mHz, which was beyond the luminance signals of the day. The chroma also tended to "wander" which is why NTSC TV sets had tint controls. PAL (which is a later standard), was modifed to 25 frames per second, with 625 lines per frame (because of the slower frame rate), with the color carrier at 4.43 mHz. The color phase of the color subcarrier is reset every other line, hence the name (Phase Alternating Line), which eliminates the need for a tint control. The standard is that NTSC derived signals are 30 frames per second, PAL are 25, except that Brazil uses 30 frames per second PAL over the air. Since there are no such thing as 30 frames per second PAL DVD's. I expect the DVD players converted NTSC disks to PAL signals on the way out, and upconverted 25 frames per second PAL disks to 30 when playing them. It's becoming a moot point, because MPEG level 4 encoding, aka DIVX and H.263 or H.264, does not have a fixed frame rate. Except for key frames, if the image does not change, there is no encoded data. It's up to the playback device to repeat any intermediate frames as necessary. Geoff. -- Geoffrey S. Mendelson, Jerusalem, Israel gsm(a)mendelson.com N3OWJ/4X1GM New word I coined 12/13/09, "Sub-Wikipedia" adj, describing knowledge or understanding, as in he has a sub-wikipedia understanding of the situation. i.e possessing less facts or information than can be found in the Wikipedia.
From: William Sommerwerck on 1 Apr 2010 05:48 > Note that the chroma information is the same with NTSC or PAL > signals, the difference is how it is added to the signal. NTSC > signals added the color at a subcarrier frequency of 3.57 MHz, > which was beyond the luminance signals of the day. The transmitted luminance bandwidth was always 4.2MHz, even before color. > PAL (which is a later standard), was modified to 25 frames > per second, with 625 lines per frame (because of the slower > frame rate), with the color carrier at 4.43 MHz. The color phase > of the color subcarrier is reset every other line, hence the name > (Phase Alternating Line), which eliminates the need for a tint control. That's not quite right. The belief that NTSC is a stupid design, and PAL corrects all the bone-headed elements of NTSC, is untrue. The original NTSC proposal was actually PAL (I have the copy of Electronics magazine to prove it), and NTSC is, overall, a less-compromised design than PAL. I still don't understand how a single data set can be /easily/ converted to 480 lines or 576 lines. Notice I said /easily/.
From: Dave Plowman (News) on 1 Apr 2010 05:48 In article <slrnhr8odc.t4o.gsm(a)cable.mendelson.com>, Geoffrey S. Mendelson <gsm(a)cable.mendelson.com> wrote: > >> The data is formatted as either PAL or NTSC on the disk. > > > > Phased Alternate Line? How interesting. > > > The term PAL in reference to the DVD refers to the picture encoded, > originally a PAL (or SECAM) 50 fields per second interlaced picture > with 1:4 chroma data. > The encoded signal is 25 frames per second, and still has the same chroma > information, but the chroma is stored separately in the data stream, the > way it was on a separate track on VHS/BETA video tape. > It's up to the player to figure out how to play it. To be played on a > standard TV, the frames have to be cut down to 625 lines, and split into > two fields before being played on a PAL TV. The chroma information has > to be phase encoded and added as a color subcarier. Indeed. All down to the player. Most UK (PAL) TV/VHS combinations would play genuine NTSC tapes - via a bit of a cludge. But I don't think the reverse was true in the US. These days, many TVs will accept any broadcast frame and field combination. And others too. My DVD plays 'NTSC' discs happily on my TV. -- *You! Off my planet! Dave Plowman dave(a)davenoise.co.uk London SW To e-mail, change noise into sound.
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