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DirecTV National HD Listing/Maps Discussion Thread (Technical - Not Anticipation)

Discussion in 'DIRECTV Programming' started by Sixto, May 29, 2012.

  1. Jul 4, 2012 #261 of 653
    inkahauts

    inkahauts Well-Known Member

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    !rolling
     
  2. Jul 5, 2012 #262 of 653
    georule

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    This doesn't need to be a theoretical discussion. There are several high-profile channels that D* is already doing this with, and yet the DBSTalk community, which has many "PQ Hawks", hasn't raised a flag as of yet.

    The content is out there. The burden of proof is on the doubters to bring in some evidence from the publicly available evidence. Let's see your screenies.

    I'd be very surprised if engineers of the competition aren't trying very hard to punch holes in D*'s new methods. . .and would be more than happy to pass their results along, if they can find any smoking guns, to friendly surrogates in the online community. Try not to look shocked at the suggestion.

    Where are they?
     
  3. Jul 5, 2012 #263 of 653
    maartena

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    For some reason, I believe Xizer is here just to troll. Not quite sure if he really knows how DBS satellite works and what its capabilities are. Hell I don't know close to a quarter of it, but he just is here..... well, I actually really don't know why he is here.
     
  4. Jul 5, 2012 #264 of 653
    veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    Should you post any of these channels, I'll try to pick them apart.
     
  5. Jul 5, 2012 #265 of 653
    dpeters11

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    While of course anyone can find out what channels are on a transponder with 6, I bet if we actually named them, someone would say that they saw a difference even if it's more psychosomatic.
     
  6. Jul 5, 2012 #266 of 653
    Sixto

    Sixto Well-Known Member

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    Thanks VOS.

    Maps at:
    It's the transponders with 6 HD channels, with the 6th at 1060 or 1070.
     
  7. Jul 5, 2012 #267 of 653
    Sixto

    Sixto Well-Known Member

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    D11 TP3 ... D12 tp 9, 10, 13, 15 .. gotta run ... later ...
     
  8. Jul 5, 2012 #268 of 653
    georule

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    I don't know if there are any other source provider caveats in that list, but I have heard that AMC Networks is already overcompressing AMC before it gets to D* (or anyone else).

    But thanks to VOS for stepping up.
     
  9. Jul 5, 2012 #269 of 653
    dpeters11

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    tp 10 is probably the highest profile, followed by 13 and 15.

    I'd agree on AMC though. You can't just look at the quality coming to you, but what DirecTV gets to send out.
     
  10. Jul 5, 2012 #270 of 653
    tonyd79

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    Yes, been talked about a ton at dslreports for Fios (and I can see it for myself).
     
  11. Jul 5, 2012 #271 of 653
    veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    I can't believe this "outrage", as it looks like a tempest in a teapot.

    I started sorting through Sixto's map of TPs to figure out which channels were worth recording and then sorting out the bit-rates of the MPEG-4 streams, over time. In doing so, it seems fairly clear these TPs with more channels are due to the stat-muxing being tweaked a bit.
    I've been watched many of these channels and if there is a problem with this many on one TP, it may be when the stat-mux "goofs", which could explain the moments of slight pixelation, as the peak MPEG-4 bit-rate gets limited.
    I was on a DMA with 6 HD channels on one TP for a few years and with MPEG-4, it works.

    If you've monitored MPEG-4 HD streaming, you know the bit-rates vary widely, from as low as 1 or 2 Mb/s, to a "general norm" of 7-9 Mb/s, to peaks in the 12-16 range.
    What I see in the TP maps, is DirecTV optimizing their bandwidth usage.
    I don't see any signs of "over compression" [been watching some of these channels], but suspect the weak point to be when the stat-mux can't allocate enough bandwidth for every channel's needed bit-rate, which might manifest as picture breakup for a few frames.
    I might see this once or twice in a two hour movie.

    Considering the work and effort to try to map out the bit-rates of all the channels on one TP, and then try to sync them in time to each other, it isn't worth it, when I expect this is exactly what the mux is doing.
     
  12. Jul 5, 2012 #272 of 653
    cypherx

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    Yes AMC Networks statmuxes 4 HD channels together to be able to fit in one QPSK transponder or one 38.8mbps cable QAM channel. It's MPEG2 though so cable operators can just receive the whole package and translate it on one QAM frequency.

    [table]Galaxy 14
    3740 V DVB-S
    SR: 29270 Mod:QPSK FEC:5/6
    Encryption: PowerVu

    vpid: 102 - AMC East HD
    vpid: 104 - We East HD
    vpid: 106 - IFC HD
    vpid: 108 - Fuse HD
    [/table]

    I've done a QAM analysis on Blueridge cable since their Passport software on a Cisco STB has a really thorough diagnostics mode. They run that same mux with the same vpid's and everything. It's like a direct translation from Galaxy 14 to a single 38.8mbps QAM. Not sure how DirecTV or others get this programming, but I don't think AMC wants to "encode it twice". That costs more money.
     
  13. Jul 5, 2012 #273 of 653
    studechip

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    This reminds me of audiophile snobs. Their system sounds good because the numbers say it should. They don't listen to the music, but to the equipment.
     
  14. Jul 5, 2012 #274 of 653
    Hoosier205

    Hoosier205 Active Member

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    Compared to who? Dish? Yes!
     
  15. Jul 5, 2012 #275 of 653
    maartena

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    Do you mean the streaming of recorded content, that was previously delivered at 5.7 Mbps?

    I don't know the exact encoding U-Verse uses on its DVR, but a program in HD could be recorded on the DVR using a different type of compression, meaning the end-result on your hard drive is of such a format, that in order to stream it, it needs more bandwidth.

    In THEORY, you can record the incoming TV stream into an uncompressed format, and you would end up with e.g. a 40 Gb file on your DVR for an hour show, which in turn, once played by a STB elsewhere, would require about 90 Mbps to play. That does not increase the quality though, it is just the way it was stored.

    From that point of view, it would probably make sense that U-Verse (and any DVR actually) would store the incoming recording in a file compression method that does not compress the file any further, yet allows for quick play/access without too much CPU work.

    U-verse DVR's have 320 Gb I think (some have 500). A portion is reserved for the OS, but you can probably calculate how much space a 1 hour show takes on your DVR, and in turn you can then calculate how much it would take to play it in Mpbs.
     
  16. Jul 5, 2012 #276 of 653
    HoTat2

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    Likely through that same C-band satellite feed off one of those massive Simulsat dishes typically seen installed at the broadcast centers.

    Then the AMC multiplex is demodulated, demux'ed and at some point in the broadcast signal chain the individual AMC channels go through MPEG-2 to 4 transcoders before eventual statmux and uplink on DIRECTV's satellite system.
     
  17. Jul 5, 2012 #277 of 653
    veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    I'm having a bit of a hard time following what you're trying to say here.
    I sent U-Who [TV] packing back at the end of March, so I can't check anything out further.
    I had their 500 GB DVR, which claimed I had 165 hr. of HD recording time.
    Clearly their idea of an hour of HD uses less than DirecTV's 100 hr. for the same size drive.
    I doubt any DVR is doing "encoding" to the drive. DirecTV is "decoding" in the SAT tuner and outputting to the drive.
    I imagine U-Who is just like DirecTV VOD, and simply writing the file to the drive, or sending it to a receiver, when the DVR is busy recording its max.
    If I still had the service, I'd try to check out this "5.7 Mb/s" that you've posted, as I don't think it was what I was getting here.
    I tired to find the data I took comparing a TNT recoding between DirecTV and U-Who, but only have the results, and not the worksheet that show them. I'm "fairly sure" I saw higher bit-rates than 5.7 Mb/s, but also never saw 8 Mb/s, when DirecTV was over that, at the same time in the program.
     
  18. Jul 5, 2012 #278 of 653
    maartena

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    I assumed that when you said "from the DVR" you meant streaming something FROM the DVR to another STB, and that you would see higher bitrates between the two devices. I might have misunderstood.

    In any case, U-Verse HD is pretty much FIXED at 5.7 Mbps (plus a little overhead, basically about 6 Mbps per channel), and doesn't go beyond that, as far as channels coming in to your home are concerned.
     
  19. Jul 5, 2012 #279 of 653
    veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    Yes what I did was to monitor my router ports, and then play a recording from the U-Who DVR to their receiver, while using DirecTV2PC to stream the same recording from a DirecTV DVR.
    Both were sync'd within a sec or so to have the router traffic be meaningful. The router was sampling on one min cycles.
    You're being fairly adamant about this 5.7 Mb/s, which I can't check, but the DVR does [or can] stream above this. [again] the into house rate may be such that the DVR is able to buffer so it can send higher rates for short times as needed by the recording.
     
  20. Jul 5, 2012 #280 of 653
    maartena

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    Yes... like I said, once a program is stored on the DVR, it uses a different method of delivery from the DVR to a STB in your house, which in turn could easily mean a different, and higher bitrate then the bitrate the program originally came in with. For starters is it placed on a TCP/IP network that is configured for general usage, where although the delivery of U-Verse IPTV also is over TCP/IP, it is delivered over a private network specifically optimized for video delivery (e.g. packet size, MTU, and other variables). There are some other difference that could explain a bitrate difference between the actual delivery of the original content, and the distribution from the DVR to clients.

    The same is true for DirecTV2PC, which probably delivers the program at a constantly maintained bitrate from the DVR, whereas the bandwidth used on the actual transponder to deliver the programming to your house, might fluctuate depending on the content (e.g. sports w/lots of action, or a talk show with mostly silent background).
     

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