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ota recording

Discussion in 'DIRECTV HD DVR/Receiver Discussion' started by bscolvin, Aug 22, 2007.

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  1. bscolvin

    bscolvin Mentor

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    Aug 19, 2007
    Do you think it will be possible to do two sat rec. plus and ota rec. with the hr20? If they did an update to the box.
     
  2. vegasflyby

    vegasflyby AllStar

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    Aug 7, 2007
    No...Since there are only two buffers/tuners.
     
  3. Stuart Sweet

    Stuart Sweet The Shadow Knows!

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    Specifically, the decoder chips in the HR20 only allow for two simultaneous streams.
     
  4. micky76ag

    micky76ag AllStar

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    Feb 18, 2007
    I have no idea about what’s possible hardware wise in the box, but I‘m pretty sure the number of decoders should not be a limitation on number of simultaneous recording streams.

    The signal is not decoded before it is recorded, is it? I would think it only decodes during playback.
     
  5. Tom Robertson

    Tom Robertson Lifetime Achiever DBSTalk Club

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    While the E* VIP has the same basic chipset and can do this, I'm not sure the HR20 is physically wired to be able to. I don't know if the streams are forced thru a dual only path at some point or not.

    At this point, it can not whether by software or hardware is unknown.

    Cheers,
    Tom
     
  6. cartrivision

    cartrivision Hall Of Fame

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    I thought that the raw video stream was written to the disk as is (encrypted) and only decoded when you watch it, which would mean that you only need one decoder (or perhaps one sat stream decoder and one OTA stream decoder).

    I suspect that the sat and OTA recording and decoding capabilities are two different paths or circuits in the hardware which could mean that the part that writes the OTA stream to the disk is unused while recording two sat channels, and that it might be able to be used to write a third program to disk if there were no other bottlenecks in the hardware preventing it.

    On the other hand, if you only need the decoders to watch the stream after it's read off of the disk, the number of decoders wouldn't have anything to do with how many of the four tuner streams could be recorded to the disk, although there may or may not be other hardware limitations which limit the HR20 to a maximum of two recorded streams.

    I'm hopeful that the supposed "mistake" in the original HR20 manual that stated that you can record 2 sat and one OTA stream simultaneously was based on the fact that the hardware is capable of doing that and that the capability will be included in a future firmware release.
     
  7. Tom Robertson

    Tom Robertson Lifetime Achiever DBSTalk Club

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    Some separation of modulation, encoding, and encryption is necessary: modulation is how the bits are transmitted over the medium (8psk or QPSK), encoding is how those bits define a video stream (MPEG2 or MPEG4), and then encrypted is how those streams of bits are created such that they can't be viewed by simple decoding the MPEG2/4.

    And there are layers of security, but that is all that can be said on that topic.

    Basically the DVR does demodulate the signals separating the streams into individual channels or OTA subchannels, then records that channel directly to disk (ignoring what security things might be happening.) But there might be a choke point at the demodulation level where perhaps only two items can be demodulated at once.

    Or it might be software.

    Cheers,
    Tom
     
  8. cartrivision

    cartrivision Hall Of Fame

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    That at least gives us some hope.

    Stewart, given the above information, what do you base your statement that, "the decoder chips in the HR20 only allow for two simultaneous streams" on?
     
  9. oenophile

    oenophile Godfather

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    Dec 1, 2006
    Northern...
    Total newbie question (sorry): Can you record two off the dish and watch an OTA? I presume you can't do that either (b/c due to buffers you effectively are recording what you're watching), right?
     
  10. vegasflyby

    vegasflyby AllStar

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    Aug 7, 2007
    ^^ Right.
     
  11. Milominderbinder2

    Milominderbinder2 Cutting Edge: ECHELON '08

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    I do this occasionally by just watching the OTA that is split into the HDTV.

    This trick is brought to you by the...

    Undocumented Tips & Tricks

    Supercharge your day with 133 great tricks for your HR20! :)

    - Craig
     
  12. cartrivision

    cartrivision Hall Of Fame

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    That's nothing, while my HR20 records 2 HD DirecTV channels, I can also record 4 SD DirecTV channels.
     
  13. oenophile

    oenophile Godfather

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    Northern...
    Great idea, thanks. Does the quality of the HD signal degrade much when you split it?
     
  14. Stuart Sweet

    Stuart Sweet The Shadow Knows!

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    To quote Earl, :D
     
  15. cartrivision

    cartrivision Hall Of Fame

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    I don't understand your answer. Does that mean that you stand by your statement, or that it may have been wrong?
     
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