Phillips 963sa - 13bit/108MHz video processing,what does this mean?

Discussion in 'Blu-ray & DVD Players & Recorders' started by jonny m, Jul 12, 2002.

  1. jonny m

    jonny m
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    Is Mpeg2 encoded on disk at say 8 bits per channel? If so I don't understand why a 10/12/13 bit DAC would help create a better picture.

    Does the mpeg2 decoder do blending operation's on the image, or does the 13-bit dac extrapolate the 8 bit mpeg2 data to be 13 bits for finer graduations smokey scene's.

    :confused: :confused: :confused:

    I think cd upsampling works by smoothing out the square waveform that has arisen because of the 44htx sample rate.BUt how does a 13 bit dac upsample mpeg2 data??

    Confused to say the least.

    Any genius's out there prepared to explain??

    Cheers
    J
     
  2. MartinCo

    MartinCo
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    no genius, but I do remember reading something of an explanation at avsforum.com.. have a look there for more detailed info.

    the end result seemed to be that yes, there were benefits and resulting improvments in the picture quality.

    a few players seem to be coming out with the 108mhz dacs, most of the new Denons for example describes them as doing "Noise shaped video" or similar silly phrase.
     
  3. GarethH

    GarethH
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  4. jonny m

    jonny m
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    Thanks for above pointers, according to various discussions it seems to produce a better image as like upsampling cd, it produces finer graduations in the colour...

    i wonder if it's abit like if you run your pj at 800x600 but use your pc to give it a dvd image at 1024x768, the dvd software has to create more information from the data sample its 'upsampled' then your pj reduces the image for display and in the process it looks smoother as if it is run at a higher image anyway...

    still would like to know and whether or not it will have much effect when been fed to my lcd pj which wil probably only sample at 8 bits per pixel!

    ps. please ignore all the above:p

    j
     
  5. Xeonic

    Xeonic
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    Actually, don't ignore the link gareth posted, cos that's your answer and you'll need it for this! ;)

    Imagine the source signal, of 12Mhz range is put throught a 27Mhz DAC. A side effect of that process means the signal is "repeated" after half of 27Mhz level, i.e. 13.5Mhz. These are pink blocks after the blue one on the diagram. The DVD player has to cut off these blocks above that level - this is done using a filter.

    It is difficult for a real-life filter to just chop the signal off after a certain point, instead, the signal gradually rolls off to zero. This means that some elements of these repeated signals get mixed with the original, producing interference at higher frequencies - the red bits pointed to on the diagram.

    Now if instead of using a 27Mhz DAC, a 54Mhz, 108Mhz e.t.c DAC is used, what is happening is we are pushing the repeating range further out. With 108Mhz and 13bits, the signal range is 54Mhz, and our max signal is 12Mhz and 8 bits, so the filter can do it's work with more leeway, and less interference in the output, and better "sky above barn" (I'm parapharasing the comments on the pic, since I can't read Japanese :( )

    In summary, using a 13bit 108Mhz DAC gives the player more chance to reproduce the higher frequencies in the signal better. Note this is different to the process you mention of turning 800x600 into 1024x768. This is upsampling, i.e. "creating" data between the points that really exist.
     
  6. jonny m

    jonny m
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    aaaahhhhhhaaaa! So its not about upsampling its about reducing the noise in the signal by getting an accurate sample..

    I'll need to think about this for a while..

    thanks for the reply!!

    j
     
  7. niklaskarlsson

    niklaskarlsson
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    Anybody got any more info on when this player is set for release and appr. price?
     
  8. MartinCo

    MartinCo
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    Sept was mentioned by someone awhile ago, though this is, as ever, subject to change.

    price? who knows.
     
  9. Technophobe

    Technophobe
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    Emailed Philps a week or two ago and they said it would be available by the end of the month. I will believe it when I see it though as product release dates never seem to be reliable.
    I've still not received a reply to my mail last week asking them if it will most likely be priced similar to the DVD962SA or much higher.
    All I wanted was a clue as to the likely price so I can decide if I want to order from Hivizone or wait for the UK one. :(

    Technophobe
     

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