Why do the amount on lines drop in LP?

Discussion in 'Blu-ray & DVD Players & Recorders' started by JimBob1971, Jun 15, 2005.

  1. JimBob1971

    JimBob1971
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    I was trying to decide between the pana eh50 and toshiba xs34, and yesterday finally plumped for the latter, and I must say I'm very impressed.

    However, the major Pana selling point was the quality of the LP 4 hr record. Why is it that other players cannot match this? I believe there is a certain point at which the 'lines' half, is that correct? If so, what is to stop me recording at say 4.0 instead of 4.6 in order to squeeze those last few minutes of a 2.5 hr film? Surely the difference in quality would only be minimal? Can someone explain the lines concept?

    Ta!
     
  2. redsox_mark

    redsox_mark
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    Here is a post I thought explained the technical aspect of this well:

    http://www.avforums.com/forums/showpost.php?p=1676612&postcount=11

    DVDs are compressed, rather than sending all the information all the time they send information about the changes, making some guesses to fill in the blanks. The lower the bit rate the more guesses it has to make, and the quality is impacted. Full resolution needs more bits than half. When the rate gets below a certain level, the recorder will use half resolution – basically it is better to do an accurate job in handing half the resolution than a poor job at full resolution.

    On your XS34, it will be full resolution on 4.0 or above; below 4.0 it drops to half resolution (if DVD compatible mode is on; if off it uses a resolution inbetween for 3.2 to 3.8).

    The Panasonic encoder is better, so it can support full resolution at decent quality with less bits, so it doesn’t drop to half resolution unless you are putting more than 4 hours on (a rate of 2.2 or lower I assume).

    Mark
     
  3. JimBob1971

    JimBob1971
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    Thanks Mark.

    So , anything above 4.0 will be full res? Does that include recording which will be burnt to -r and -rw? I think I read somewhere that the drop is different for DVD compatible recordings
     
  4. redsox_mark

    redsox_mark
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    Yes, 4.0 and above will be full resolution, regardless. 3.0 and lower will be half resolution regardless.

    The DVD compatible thing only comes in with rates of 3.2 to 3.8. With DVD compatible off, these are a non-standard resolution (I don't remember exactly what it is, but something less than full resolution, but more than half). These can't be dubbed to DVD via high speed dub. With DVD compatible on, these are half resolution.

    Mark
     

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