Author Topic: TV Push Question  (Read 1378 times)

leeroyjenkinsii

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TV Push Question
« on: January 23, 2009, 03:45:47 am »
I have not set this up at all.  I have a question before I do.  If I have my satellite set top box connected to a tv tuner card in one media director or the core can I push the video to a different media director/tv and watch tv in a different room even though the set top box is not connected in that room.  In other words can the video be pushed across ethernet/ip--that is live tv?

darrenmason

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Re: TV Push Question
« Reply #1 on: January 23, 2009, 04:09:27 am »
Yes, the system is capable of that.

You require a supported capture card and typically some way of controlling the satellite set top box (infrared typically) and then that will be seen by any other media director.

skeptic

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Re: TV Push Question
« Reply #2 on: January 23, 2009, 05:34:27 am »
Right now the only two options I know of to capture from a sat box are s-video/composite and firewire.  Search around for firewire topics, it's not very reliable and not available on all STBs, but it will control channel changing and such through the firewire.  Firewire also does not have a device template, so you are really limiting the LMCE functionality (Myth can still let you watch one cable box from another room).  s-video and composite are SD quality only, but look pretty good if you use the high quality settings withing Myth. 

leeroyjenkinsii

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Re: TV Push Question
« Reply #3 on: January 23, 2009, 05:56:17 pm »
Let's use an example at the following url: 

http://dishnetwork.com/receivers/hd/vip722dvr/default.aspx

If I wanted to capture the output of this box via either hdmi or component video so it would remain 100 percent digital what would I have to do?  Can I control it with an IR card?  Is there currently a capture card that could accept the hdmi and or component output as it's input?  I have read on other posts that there is currently no supported linux hardware for this and/or template.

That would be very disappointing as most people are going digital and this will be the most common format.  Some may say I'm whining here and well yeah I am...I like whining...gimme a break.  But if it isn't supported what do I need to do to help get that ball rolling.  Do I need to pester some programmers somewhere else to help?  Do I need to donate to some Paypal account?  Do I need to just take a long walk on a short pier?  Should I strip totally naked in the mall on national tv and run from end to end shouting I like chickens to bring attention to this issue?  I'll do it guys.  I'm a complete lunatic.

seth

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Re: TV Push Question
« Reply #4 on: January 23, 2009, 06:49:26 pm »
 :)
I can shed some light on the control of this device. I have it's SD counterpart the DVR 522. The IR portion of this device can be controlled quite easily with the USB-UIRT, or a GC-100. where you are going to lose functionality is on tuner 2. It uses RF for its remote, which can not be controlled by LinuxMCE, AFAIK, I ended up having to get a second receiver at a yard sale for $1, and activating that . Now I have 2 tuners that I can control with IR, and I have stopped paying for the DVR fees, although, they still get me for $5, but that is $5 cheaper than having their DVR functionality.

I however also use S-Video and Analog audio into 2 PVR150 cards. I have not upgraded to HD yet. For 2 reasons. Firstly, I still have very nice and very functional SD big screen TV's, so HD would not benefit me. Second,  there is currently no good way to capture HD content from a STB unless you use MythTV SVN, and then the driver is still very alpha for the HD PVR from Hauppagge,

But things are being developed and worked on every day, perhaps in the near future, this device can be used in LMCE, and then problem two gets solved, but there is still the whole RF thing that will prevent full functionality.

Best Regards,

Seth
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leeroyjenkinsii

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Re: TV Push Question
« Reply #5 on: January 23, 2009, 07:48:53 pm »
So if I wanted to do this and had the money to spend I'd have to get another hd receiver since only one output is controlled via ir and an hauppage hd converter (alpha driver).  Which Hauppage cards should I get?

colinjones

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Re: TV Push Question
« Reply #6 on: January 23, 2009, 11:28:28 pm »
Let's use an example at the following url: 

http://dishnetwork.com/receivers/hd/vip722dvr/default.aspx

If I wanted to capture the output of this box via either hdmi or component video so it would remain 100 percent digital what would I have to do?  Can I control it with an IR card?  Is there currently a capture card that could accept the hdmi and or component output as it's input?  I have read on other posts that there is currently no supported linux hardware for this and/or template.

That would be very disappointing as most people are going digital and this will be the most common format.  Some may say I'm whining here and well yeah I am...I like whining...gimme a break.  But if it isn't supported what do I need to do to help get that ball rolling.  Do I need to pester some programmers somewhere else to help?  Do I need to donate to some Paypal account?  Do I need to just take a long walk on a short pier?  Should I strip totally naked in the mall on national tv and run from end to end shouting I like chickens to bring attention to this issue?  I'll do it guys.  I'm a complete lunatic.


fyi

1) Forget about HDMI capture - this is an uncompressed stream, so you would need some real "big iron" to recompress it to a reasonable size for storage, plus there really isn't a raw digital input standard for PCs out there to get it into LMCE for redistribution and display, which all means you just have to send it direct to the display device (not LMCE) - LMCE can still control the STB and the display device, but you will only be able to watch that source on that display device, and not be able to record it.

2) Component is not digital, dunno where that idea came from, component (as composite, s-video, VGA, etc) is analogue.

(ps, there are cards out there now that say they can capture HDMI, really... don't believe them! Just like the early days of DVD recorders, capturing and compressing to MPEG2 for DVD recorders was a majorly heavy duty job, so typically the image quality was appaling. Hardware has gotten better, but now you are talking about capturing maybe at least 1.5Gb/s and compressing that real time into H264, there is nothing out there at anything approaching a reasonable price at the moment that will do that. Also, the holy grail for capturing DTV is finding a provider that will allow you to use your own hardware to decode so that you bring the digital stream directly into the LMCE box with a PCI card and skip the STB altogether. They do exist, but it isn't common!)
« Last Edit: January 23, 2009, 11:32:42 pm by colinjones »

leeroyjenkinsii

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Re: TV Push Question
« Reply #7 on: January 24, 2009, 01:46:59 am »
Thanks for the info on component video.  I did think it was digital.  Apparently there is digital component but I don't think it's carried across the three cable standard component type.

Ok.  Here's what my conclusions are.  LinuxMCE in no way can push full HD content from a STB to other media directors over Gig Ethernet.  Apparently even though a small set top box from Dish Network can unencrypt the HD satellite signal and push the HD out of the HDMI port, a pc (no matter how beefy) cannot take that signal and push it to other pcs over Gig E.  I assume since this is the case that LinuxMCE also cannot push a Blue Ray disc players output to other Media Directors/TVs.

Also, the Holy Grail you spoke of will not be reached with Dish Network because they don't want that.  It's not as profitable for them.  I believe you may be able to get a Cable Card with like Road Runner or Direct TV but even then you are locked out of some content like PPV. 

So to sum up.  LinuxMCE is only good for old school non-HD formats or maybe having all your content already compressed into say AVI/DIVX format and playing from a central server.

colinjones

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Re: TV Push Question
« Reply #8 on: January 24, 2009, 03:27:29 am »
Let me try to clarify this for you.

The issue here is nothing to do with digital nor HD - it is entirely to do with encryption - in this case, of pay TV channels. Providers like Dish are using standard DVB-S/S2 to transmit the digital TV, any DVB-S/S2 card can receive and demux these signals directly into any TV capable media centre like LMCE. However, because access is controlled due to the majority of channels being pay TV, the content itself is encrypted. The only ways to decrypt the content is either with a CAM/CI decryption module from Dish plugged into your DVB card (this is a part of the DVB standard) or by getting an equivalent card from somwhere else. The latter is, of course, of dubious legality. However, not of morality assuming you are paying for the same service anyway. Either way, we cannot discuss that option here - you will need to look into that yourself!

Forget the digital component thing - no idea what that is, but "digital" and "component" are almost mutually exclusive in that there is no point in splitting a digital feed into components. I think you may have misunderstood some other technology. Either way, it isn't relevant here.

"push full HD content" across a LMCE network is not accurate, nor what I was saying. Put simply, HDMI is an uncompressed video stream - it isn't intended for video network transport, storage or distribution, so rather than go to the effort and expense of compressing it (lossily) sending it from your receiver/BD unit to your TV and then decompressing it again, it is left uncompressed and sent as is, because there are no disadvantages to doing so, and it saves money on hardware and retains identical quality. However, you are talking about taking that stream and using for "network transport, storage or distribution" and so you will encounter the disadvantages of not using HDMI for the designed purpose. Primarily, a single HD (1080i60) stream consumes approx 1.5Gb/s. The maximum practical throughput you get from a gig network is around 300-350Mb/s, or 5x too slow.

If you can get the DVB and decryption done inside a LMCE box, then you can take the compressed video stream and redistribute it to any LMCE MD you wish, typically consuming 12-15Mb/s per stream - in otherwords you can do several simultaneously with a gig network. Decompression only happens once the stream reaches the intended MD. A very common example of this is FTA (Free To Air) DVB and ATSC digital TV channels are almost always unencrypted, and so many people on these forums routinely pipe HD TV channels across their LMCE network (including myself). And if you can find a provider that will allow you to decrypt on your own hardware, then you can do exactly the same with cable and satellite channels - ie not a technical issue, a commercial one.

The same is true of BluRay and HD-DVD - the issue isn't technical, its commercial, getting the facility to decrypt on our own hardware (the LMCE boxes in this case). The only way around this currently is how LMCE does it, and it is very limited - it rips the disks to HDD first, then plays and decrypts as it goes from the HDD. But again, it only decrypts at this point, it doesn't decompress until the stream has reached the intended MD. So, similarly, you can play a BD/HDDVD disk from one machine across the network to another. In this instance the bandwidth required is upto around 36Mb/s, from memory.

Getting from para 4 above to para 5 above, ie from an uncompressed stream from an HDMI port into a compressed stream such that it is practical to send across the network, would require the heavy duty hardware I was talking about. It exists, but to make it financially practical, you will find that the quality of compression is pretty poor.

One final point, you do not necessarily need digital for HD. Analogue component connections are perfectly capable of at least 1080i60, this is quite common in Home Theatres that don't use HDMI. You could potentially use an analogue HD capture card that has component in. Still not as good as doing all the work inside the LMCE box, but an alternative.
« Last Edit: January 24, 2009, 03:34:13 am by colinjones »

leeroyjenkinsii

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Re: TV Push Question
« Reply #9 on: January 24, 2009, 03:51:21 am »
Ok.  So if the Blue Ray Player only has an hdmi output then you're still in the same boat?  I mean the video will come out of the player at 1.5 G/s and will be useless to us.  Also if the Blue Ray Player has component video out then that would be analog and not true HD video right?

I guess you'd have to put a Blue Ray player in your actual media director so that the content can be decrypted, sent to hdd, then pushed to another media director and uncompressed out to the nvidia dvi connector through a dvi to hdmi cable and pushed into your tv via hdmi.

leeroyjenkinsii

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Re: TV Push Question
« Reply #10 on: January 24, 2009, 03:58:38 am »
I read your other post and see that component even though analog can still carry true HD like 1080p.  If this is the case and the STB has component out, I've read other posts that suggest you can capture this.  Is it a lower rate than the 1.5 Gb/s with hdmi?  Will there be any loss as compared to hdmi?

colinjones

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Re: TV Push Question
« Reply #11 on: January 24, 2009, 04:39:45 am »
That is true - as I say, still not as good as capturing inside LMCE as you can loose a bit of control, plus you are taking a perfectly good HD digital signal, converting it to analogue, then capturing that and digitising and recompressing again! But it maybe your only way because of the pay TV providers' policies.

The 1.5Gb/s is the uncompressed rate for HDMI. You will never really see the equivalent of that using an analogue capture card, as it digitises and compresses on the card and only sends out the compressed stream - which, yes, will be vastly less than this. Don't know what rate to expect, I imagine that will depend on the settings used. But fundamentally, you are still capturing a large amount of information because it is an HD resolutions. If the card was to compress with the same level of accuracy, resolution, loss, etc then you would be talking about a task not dissimilar to the HDMI thing we have been talking about. So I assume that compromises are made there as well in terms of the compression rate and accuracy.

Any time you take something to analogue and then back to digital you are going to loose some quality - done properly, that loss should be very minimal. It is the subsequent loss during compression that is likely to be most significant. The only way you are going to know the answer to that is by setting it up, then comparing the picture with the STB plugged directly into the TV via HDMI, then the same picture when feeding the STB component into the capture card and displaying on the TV via LMCE. Others have experience of these types of cards, I suggest you browse around and see if you can find reliable opinion on the quality.

In principle, yes, you can feed the STB component output into an analogue HD capture card plugged into a LMCE box. Then display that live TV on that MD or stream it to any other MD(s), or simply record it to a disk somewhere on the network for playback later. You can then use things like IR blasting or serial ports to control the STB via LMCE, and there are various options out there for importing EPG data into LMCE as well (remember, if you capture using analogue then you loose any of the digital functionality such as EPG over the air, although I'm not sure if that is used in the US currently anyway)