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picture blocking - Ntsc to Pal - CDR/CDRW

Discussion in 'Blu-ray & DVD Players & Recorders' started by simon1, Aug 6, 2001.

  1. simon1

    simon1
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    Hitachi 32WF810 & Hitachi DVP515

    I'm a bit of a newbie when it comes to dvd and hope others out there could answer these three questions:

    1. When artifacts occur sometimes on dvd playback, if I go back to just before they appeared, it never seems to do it a second time. Has the player sort of realised it's mistake and learnt not to do it again or is this just co-incidence?

    2. I'm a bit confused regarding different sorts of NTSC and PAL conversion. When I play back a region 1(NTSC)disc, the 'PAL' indicator remains lit on the player and the 'Hue' option on the tv menu is not available (which it would be if receiving an NTSC signal). There is an option in the dvd menu to select 'Quasi PAL', but if I select this the picture is distorted and I still don't get NTSC output from the player. Player is connected via rgb scart.

    The player is based on the Samsung machines. I noted on one of these Samsung machines, there was a small button on the remote, which you pressed with a pen to change from NTSC/PAL. My player doesn't have this, and there is nothing in the menu apart from 'Quasi PAL'

    To recap, picture seems fine with 'Quasi PAL' switched off, but I'm obviously not geting a true NTSC signal from either setting. Tv mentions compatibility with PAL/SECAM/PAL60/NTSC4.43/3.58. The dvd mentions compatibility with NTSC, and it's user manual simply says 'PAL indicator will light when playing back a PAL disc'

    Can anyone explain what conversion is taking place? Is this PAL60? Am I missing out by not seeing a true NTSC picture? What is the point of having the PAL indicator - no need to answer that! <br /> <br />3. When I bought my player, I went for the next model up, cos it could play CDR/CDRW discs which the cheaper Hit DVP315 and my previous Tosh couldn't. Hitachi claim that because my 515 uses a twin laser it is able to play these discs. What I can't understand is why so many of the standard dvd players can not read copied audio CD's, when every CD based audio sysem can. Is it true that a dvd player does need a dual laser for this purpose or is Hitachi spouting nonsense like many manufacturers do?

    Thanks in advance to everyone who can help.
     
  2. LV426

    LV426
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    &lt;&lt; 1. When artifacts occur sometimes on dvd playback, if I go back to just before they appeared, it never seems to do it a second time. Has the player sort of realised it's mistake and learnt not to do it again or is this just co-incidence? &gt;&gt;

    Seems unlikely - they aren't that clever. I can only guess that there is a minor flaw in the disc (or a small bit of dirt, fingerprint, whatever) that has moved the second time you play the segment.

    &lt;&lt; 2. I'm a bit confused regarding different sorts of NTSC and PAL conversion. When I play back a region 1(NTSC)disc, the 'PAL' indicator remains lit on the player and the 'Hue' option on the tv menu is not available (which it would be if receiving an NTSC signal). &gt;&gt;

    If this is the case, then I'd assume that you have the player set to output some sort of PAL. The TV will recognise the absence of an NTSC colour signal and hide the "hue" control, (which doesn't work with a PAL colour carrier). However, with an RGB connection, I suspect that "Hue" will never be available. Does anyone else know better?

    <br />&lt;&lt; There is an option in the dvd menu to select 'Quasi PAL', but if I select this the picture is distorted and I still don't get NTSC output from the player. Player is connected via rgb scart. &gt;&gt;

    Distorted - how?

    If, as you say, the player is based on Samsung innards, then the choices offered are TRUE Pal and QUASI PAL. Setting Quasi PAL off will result in a true PAL output from the S-video and Composite Video signals. However, I don't know enough about RGB to comment on how an RGB signal is affected.

    The difference between Quasi PAL and true PAL is in the line and frame structure.

    Any TV picture is defined by three factors:

    1) The field rate. NTSC is 60 fields per second. PAL is 50. Each film frame is made up of two fields, so the frame rate is 30 or 25 fps.

    2) The horizontal line structure. NTSC is 525 (480 used) and PAL is 625 (576 used).

    3) The colour carrier system. PAL is, well, PAL, and NTSC is, err... NTSC. However, again, I suspect that this is less relevant with RGB connection.

    Quasi PAL is a hybrid, consisting of the NTSC line and field structure (525/60) with a PAL colour carrier. In other words, Quasi PAL = PAL/525/60.

    Samsung (and therefore presumably, your) DVD players can also convert the NTSC field and frame structure to the PAL standard ie PAL/625/50.

    &lt;&lt; The player is based on the Samsung machines. I noted on one of these Samsung machines, there was a small button on the remote, which you pressed with a pen to change from NTSC/PAL. My player doesn't have this, and there is nothing in the menu apart from 'Quasi PAL' &gt;&gt;

    I assume (without knowing anything about your specific player) that is does NOT have a true NTSC option (ie NTSC/525/60). Unless there is another control, or switch, elsewhere. On some machines, its on the rear panel. The main reason for this is that, if the controls are exclusively menu driven, and the TV won't handle the signal, (many don't) you have no way of changing it back.

    &lt;&lt; To recap, picture seems fine with 'Quasi PAL' switched off, but I'm obviously not geting a true NTSC signal from either setting. Tv mentions compatibility with PAL/SECAM/PAL60/NTSC4.43/3.58. The dvd mentions compatibility with NTSC, and it's user manual simply says 'PAL indicator will light when playing back a PAL disc'

    Can anyone explain what conversion is taking place? Is this PAL60?

    Am I missing out by not seeing a true NTSC picture? What is the point of having the PAL indicator - no need to answer that! &gt;&gt;

    If you have Quasi-PAL switched off, but there is no "hue" control on the TV, then I'd assume you are getting true PAL (PAL/625/50).

    The downside to this is that there will be some additional jerkiness on fast moving objects, pans etc. Quasi PAL should look smoother.

    &lt;&lt; 3. When I bought my player, I went for the next model up, cos it could play CDR/CDRW discs which the cheaper Hit DVP315 and my previous Tosh couldn't. Hitachi claim that because my 515 uses a twin laser it is able to play these discs. What I can't understand is why so many of the standard dvd players can not read copied audio CD's, when every CD based audio sysem can. Is it true that a dvd player does need a dual laser for this purpose or is Hitachi spouting nonsense like many manufacturers do? &gt;&gt;

    It's true. Standard DVD lasers won't focus on the data on a CDR. They do, however, usually read CDRWs (and commercial CDs) OK. "Better" players have dual-focus lasers that CAN read CDR data.
     
  3. simon1

    simon1
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    LV426, thanks for replying.

    Quasi PAL causes the top 4" of picture to lean over to the right.

    I would have imagined Quasi PAL was intended for people whose tv was not NTSC compatible. And that with it switched off, I should get a true NTSC signal. This is obviosly not the case and I can't get any sense from Hitachi.

    I'll learn to live with it.
     

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