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Echostar DishPVR 721 GPL Software Released

Posted by ryuzaki0 on from the make-it-open dept.

Faw writes "It was mentioned before that Echostar was releasing a Linux based PVR. It has been out for a month now, and the modifications to the kernel and other software are here. The cool thing is the site is running on the same receiver. Someone is already hacking it. Wonder how long until the receiver get slashdotted."

14 of 109 comments (clear)

  1. PVR?!? When do we get PAL/Ethernet converters? by dybdahl · · Score: 3, Interesting

    A lot of people focus on Personal Video Recording, but what we really lack is the possibility to transmit video via ethernet cable (TCP/IP), so that we can have 10-20 televisions without having tons of coax cable around.

    It's very simple: One box located at the satellite dish (or TV-cable where it enters the building) receives the TV-signal and provides it via ethernet in full quality, and another box at the TV receives that signal and provides the ability to remote control the receiver via a remote control and ethernet.

    But I guess this violates the DMCA?

    Dybdahl.

    1. Re:PVR?!? When do we get PAL/Ethernet converters? by dybdahl · · Score: 3, Insightful

      This problem is very real - if you got 2 satellite dishes and 10 television sets, you need 20 satellite receivers and potentially more than 1 kilometer antenna cable to make it all work. Most people I know that have satellite dishes, are not able to watch satellite TV on all their television sets, simply because that would require too much cabling.

      If you instead put up 2 ethernet devices at the satellite dish and 1 ethernet video receiver at each television, you have reduced the number of devices by almost 50%, and instead of doing expensive and complicated antenna cabling with 3dB loss for each split, you just use your existing ethernet cables. So you have reduced the problem from something that involves a specialist to something everybody can set up themselves.

      If a TV transmission takes 2Mbps, and you have 100Mbps, there is plenty of bandwidth. If you compress it less to save hardware costs, there is still lots of bandwidth, especially if you don't use all your TV sets at the same time.

      The only problem is that this technology makes it possible to transmit pay-per-view transmissions via 802.11 wireless to your neighbors - and that's not legal.

      I see no reason to have satellite receivers, decoders, PVRs etc. at the television. To me, it's much more logical to put those into the cellar and then only have ethernet in the TV or in a single set-top box. Why not be able to view your recorded TV shows anywhere in your house instead of connecting the PVR to a single TV set?

    2. Re:PVR?!? When do we get PAL/Ethernet converters? by renehollan · · Score: 3, Interesting
      This problem is very real - if you got 2 satellite dishes and 10 television sets, you need 20 satellite receivers and potentially more than 1 kilometer antenna cable to make it all work.

      Aye. Though, you'd only need 10 receivers (unless you wanted to watch and record different channels at each TV site). I have two satellite LNBs (well only one dish), and 6 coax drops in the house, with two RG6/U cables to each drop. Not quite a kilometer, but the Home Depot guy did think I was insane for buying 2000 feet of RG6/U. It was enough. Barely.

      Most people I know that have satellite dishes, are not able to watch satellite TV on all their television sets, simply because that would require too much cabling.

      That, and the need for an extra $5/month receiver at each TV. Generally you don't watch different programs at every TV at once, so, the number of receivers can be smaller than the number of TVs. But, the current head-end solution involves analog transcoding of the received channel to in-house cable channels. This is expensive, and results in lousy quality. But, yeah, running 2xRG6/U and 2xCat5e to a bunch of drops results in a surprisingly thick cable bundle. Dropping the RG6/U would be nice.

      If you instead put up 2 ethernet devices at the satellite dish and 1 ethernet video receiver at each television, you have reduced the number of devices by almost 50%, and instead of doing expensive and complicated antenna cabling with 3dB loss for each split, you just use your existing ethernet cables.

      Er, you don't split satellite signals that way: the receiver controls the selection of the LNB and polarization with either a voltage and 20 kHz signal (DirectTV), or a digital signal (diSeq, I think, used by USSB and maybe Echostar, not sure). The lines are home-run. What you describe can work, but then the "extra" TVs are slaves to what the "primary" selects, and can only tune the primary LNB/polarization channel set. There are "stacked" LNB systems that take the two polarized channel banks and put them on the coax at the same time, but then you're driving the cable out to 2 GHz, and signal fades real fast -- slope compensators are almosta a must.

      If a TV transmission takes 2Mbps, and you have 100Mbps, there is plenty of bandwidth.

      The raw MPEG2 stream can be some 10 Mb/s, IIRC. HDTV is closer to 30 Mb/s, so you will fill a 100 Mb/s switched ethernet pretty fast. I can't see avoiding having the tuners at the headend, and just streaming the single program you want (PVRs would go at the headend too and two program PIP might be feasable).

      The only problem is that this technology makes it possible to transmit pay-per-view transmissions via 802.11 wireless to your neighbors - and that's not legal.

      So? Don't DO that.

      I rip movies from DVDs for eventual serving to STB thin clients (over ethernet, yay!) (which, by it self probably violates the DMCA: phhhhbt), but it stays in my house behind my firewall. I don't redistribute copyright material to others.

      I see no reason to have satellite receivers, decoders, PVRs etc. at the television. To me, it's much more logical to put those into the cellar and then only have ethernet in the TV or in a single set-top box. Why not be able to view your recorded TV shows anywhere in your house instead of connecting the PVR to a single TV set?

      Why not indeed? Because the technology to do this can also facillitate the illegal redistribution of copyright material outside your house. So, we suffer: it is criminal, in the U.S.A., at least to offer such devices, and to describe how to make them. No "self-respecting" company is going to risk offering them. We, therefore, are left to our own morals and devices, and risk arrest for breaking stupid laws.

      --
      You could've hired me.
  2. File Format... by SealBeater · · Score: 4, Interesting

    Almost forgot, what's the file format for the archived video? Is it straight MPEG or something propriatary? Can I install NFS or somesuch on it? Sorry, it's just a day for questions apparently.

    SealBeater

    --
    -- Its survival of the fittest...and we got the fucking guns!!!
    1. Re:File Format... by Kagato · · Score: 3, Informative

      The 721 uses stock PVR functionality built into a broadcom chipset (interestingly enough the chipset supports both HD and SD). The broadcom chipset provides hardware DES3 encryption for PVR archive functions. It's likely dish enabled the encryption because at a hardware level they don't lose much as far as clock cycles go.

  3. GPL violation? by ortholattice · · Score: 4, Interesting
    From the "DishPVR 721 Source Code" page: "Do not replace or add any software to the DishPVR 721 with items compiled from these source trees. Doing so will void all warranties and cause the unit to fail."

    Well, if replacing a piece of software recompiled from the source tree causes the unit to fail, that means the binary must not correspond to the source. Thus the GPL'ed source must have had further, secret modifications that are not being released. Isn't that a violation of the GPL?

    1. Re:GPL violation? by Jade+E.+2 · · Score: 4, Informative

      You're missing the point. The restrictions you're talking about only apply when you're using someone else's GPLed code. In this case, since it's their own code, they can do it however they like, including releasing 2 versions, a non-GPLed binary version including the proprietary bits (inside the boxes) and a GPLed source of the non-proprietary bits. If they had taken someone elses GPLed code and used it, then they would have to release the whole thing or nor use that code, but since they own the code they can do with it what they like.

  4. Easily done. by FreeLinux · · Score: 3, Interesting

    This is easily done, and no, it does not violate the DMCA.

    The TV signal is first encoded using an MPEG or similar format. This encoded signal is then streamed on the network via multicast. There are plenty of these systems out there, most are rather expensive but, they do exist and it can be done with Linux. The trick is to have a powerful enough box to do the realtime MPEG encoding.

    Commercial versions of this are used for desktop video conferencing, distance learning and even entertainment transmission. Nothing sells highend networking equipment better than a demo with a Top Gun DVD broadcasting to a dozen PCs and TVs around the room.

    1. Re:Easily done. by dzeuthen · · Score: 3, Insightful
      This is unfortunatly not going to happen anytime soon.

      Since Echostar is a DVB-compliant satellite network the different channels are encoded as MPEG2 a/v streams are put in number of multiplexes of about 30 Mbps (this gives 5-10 services per multiplex depending on quality).
      Using error-reducing codes, each multiplex is coded onto an analog transponder which is about 33Mhz wide. Remember that one transponder can carry one analog tv service.

      Thus, the set-top box would (in the worst case) require one tuner per endpoint in your ethernet network.

      There is a host of other problems I dont want to mention here including the scrambling systems, smart cards and digital rights management.

  5. GPL? Um, nope... by haukex · · Score: 5, Informative
    Please note that the DishPVR 721 software also includes some proprietary elements that are not subject to the GPL. You cannot perform a working DishPVR 721 software build without the additional proprietary code.

    This discussion was held before but here goes:

    Combining two pieces of software more than just calling each other through the shell constitutes them being one program, especially in this case where the software won't even *compile* without the missing (proprietary) code. This is not allowed under the GPL - either the entire software is released under the GPL or you can't release it under the GPL at all. (see here)

    Admittedly, it's nice of them to release the code and make it avaliable to the public, I'm sure it'll be interesting for everyone - but once again, the GPL is beaten.

    1. Re:GPL? Um, nope... by darkwiz · · Score: 3, Insightful

      Notably missing from the posted code is anything capable of recording. It may be that the recorder is a key element missing.

      You may be able to compile it, but you won't end up with a PVR.

      It looks to me, superficially, as if they are doing *exactly* what is required and nothing more. You can't fault them for that, their value add is the recording facility. If they give that away, there is little for them to build a business model on other than a Tivo'esque subscription.

      Of course, as these make it into geek hands, and they are opened up and inspected, we will get a better idea as to whether they are being as compliant as they appear.

    2. Re:GPL? Um, nope... by mikec · · Score: 3, Informative
      You're oversimplifying. Actually, it is extremely unclear what constitutes being "one program". The GPL FAQ says it's ultimately up to a judge, and goes on to speculate in an extremely vague fashion about what may and may not constitute combining two parts into one program. There has only been one court case (Nintendo vs. Goloob Games) and the ruling was not definitive.

      Even the question of whether dynamic linking is covered is somewhat questionable. To quote RMS,

      "I think we have a pretty good argument that nontrivial dynamic linking creates a combined (i.e. derivative) work. I have an idea for how to change the GPL to make it clearer and more certain, but I need to see if we can work out the details in a way that our lawyer believes will really work."

      Even assuming that the FSF prevails in this argument, it is far from clear that programs connected by pipes, shared memory, CORBA, or SOAP would be considered "one program." In fact, the GPL is so weak in this area that it's one of the main reasons for GPL version 3.
  6. Starband by GigsVT · · Score: 5, Interesting

    Echostar/Starband still will not release client specs to allow Linux computers to directly connect to starband satellite modems with normal speeds.

    You can connect the Linux box to the satellite modem, but it operates at around 64kbits up/down, with the windows client installed, it gets more like 768 down 64 up. Many people have requested the specs to write a driver for Linux, but they were told that the specs would not be given out to support the development of any sort of open source driver.

    Don't get the idea that Echostar is Linux friendly. Starband proves that.

    --
    I've had enough abrasive sigs. Kittens are cute and fuzzy.
  7. Re:a couple geek questions by brad3378 · · Score: 3, Funny

    > I noticed that there is a phone jack on the back. [ideamaster.com] But I only have a cell phone. Is it likely I'd be able to use some VOIP box for this thing to connect? Could it connect using the USB porn intead?
    Also, I have an apartment, so permanently installing this thing wouldn't be an option for me. Is it likely I'd get a decent signal through my window? (assuming I can get a good path)

    The real question would be what do you plan on buying one of these for?

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