Hello. I'm looking to replace an entire rack of VCRs with MythTV boxes.
Depending on performance, I'm guessing 4 machines each with 4 capture cards. The final destination for the data will be web streaming for the most part, but some material will go to DVD.

I'm looking for recommendations on capture cards specifically, but any other suggestions would be greatly appreciated.

I've been experimenting with one single PVR-350 card and a P4 with mixed results. We don't need HDTV, and a decoder chip would be good so we can monitor things in realtime.

Thanks, and if this all works out we'll be taking a good look at how much money we saved over commercial solutions!

You should be able to support 4 PVR cards with any relatively capable machine. All you need is enough free slots on the motherboard, and working DMA on the disk drive(s). Actually given 2 PVR-500s you can capture 4 streams with just two cards, and we probably even have people here who've already done it.

You may want to offload the streaming to another box but that'a a refinement.

Thanks for the reply, tjc.
We have real Linux admin to handle a separate machine running Darwin Streaming Server. Of course another challenge is getting the recorded data automatically prepared and piped over to the streaming server. We'll probably install a local gigabit network, too.
I've looked over the specs of the PVR500 and it looks nice, but we need composite/S-video. The coax connectors are useless to us. I didn't notice that the 500 has a decoder chip, either.
We have an oldschool patchbay hooked up to mixers and PA equipment for classrooms. We like the flexibility, and our VCRs are wired up already, so installing the PVRs will be very easy.

It has composite/S-video inputs. If you aren't interested in recording cable, then the dual tuners of the 500 probably doesn't help (I don't think it has dual composite/S-video inputs).

How will you control the devices you're feeding into the composite/S-video inputs?

As for MPEG decoding, the PVR-350 is the only one that provides this and the composite/S-video output that goes along with it. However, I think there are problems with the 350's video output in some current releases of KnoppMyth. Plus, if you are looking to have multiple 350s play back simulaneously from the same machine, I'm not sure that's possible.

There is a work around for this here: http://mysettopbox.tv/phpBB2/viewtopic. ... 1&start=60

someone i think even said they got two tuneres working with the work around. four... that i don't know. the version befor d1 (c7) accepts pvr cards without a hitch. just use that version and you should be fine...

/tk

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Re: Controlling devices. The cameras in our classrooms are wired through the building and come out in back of our patchbay. We have Panasonic and Marshall triple-set monitors for the cameras we use the most. We also have PTZ controllers on the patchbay. We have microphones in the rooms piped into our patchbay to mixers and amps. So we're not big on playback, but we do need to monitor things.
Re: 350 cards. I am running C7 right now. I went to D1 but it just didn't work, and I'm such a noob I went back to what I had better success with.
I like the 350's and buying 15 more isn't a big deal. I'm just wondering if that's the best card for my purposes.
Keeping this thread relevant to Knoppmyth, we were also thinking of some kind of netboot solution, or other ways to take advantage of Knoppmyth's flexibility and ease of setup. We could instead of having 4 bigger machines each with 4 capture devices, go with 16 little machines with one capture card. That way if one of them cooks we can quickly and easily replace it. It avoids the all-eggs-in-one-basket problem.

Thanks so much for the responses. This project is really getting a shot in the arm, and I'm ralleying The Powers to make some kind of donation.
-db

Again, I think the deciding factor is if you can actually use four 350s and their four video-outs simultaneously. If you can't, or you don't need to, you could do one 350 for its output and three 150s.

Remember that it's not as if the video-outs are "passthrough" outs for the video input signal... everything gets recorded and playback is handled by MythTV (in this example). If you wanted four individual feeds of the four individual inputs, I think it would require four individual instances of the MythTV frontend running on the lone machine.

That or I'm misunderstanding what you're trying to do.

No, I think you get the idea.
I was hoping the 350 had a pass-through feature, which according to your message it doesn't seem to. This is one reason why we might want to go with one small-n-cheap pc per card. This might be a scheduling nightmare.
I need to get a second 350 to play with and find new and interesting issues.
The amount of footage we are talking about capturing and keeping on a 3-week rotation approaches a terabyte of raw material, but of course rendered down to stream will be a lot less.

There are some outboard encoder boxes that might be worth looking into. They connect via usb 2.0 and the better ones do real-time mpeg encoding in the box so the stream isn't that difficult to handle. I should be able to remember the names of these things, but I've slept since then...

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Thanks for the suggestion.
I have browsed some of these products, but I haven't seen any that will let me monitor in real time. Of course, it could be I don't know the products well enough to tell the difference. I need to see the information on both ends of the recording device. Let's say there is a product out there that fits the bill, I wonder how many of these outboard encoders I could put on one machine, where would the bottleneck(s) be?

The 500 comes with(or maybe you have to buy it sep, not sure) a bracket that gives you a second S-Video, etc ports.

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Thanks for that correction; good to know.

Comes with. See the pictures here- http://www.newegg.com/Product/Product.a ... 6815116628

Hi,
I get the impression you are wanting to run this as more of a security situation? Three week back log? School? 24 hour / 7day?
But then again, I don't follow the streaming part.. as that would not be a security function. If it is security, then maybe a look at "motion" may be the preferred path. Works very nicely in R5C7 & above.

If you are not concerned about play back, then knock down the sample rate to at least the level of the cameras, or go even lower to match the quality of a dirty head vcr. They have 750 gig drives now and should easily give more than a few days even at 24/7. You can obtain decent play back at ~1.2 gig per hour storage rate. (750 / 1.2 ) / 24 = days

Programming is easy also, last time I set mine up was last fall (05), running A26. A30.2 seems to be better once stablized. Do it all with the a web browser (don't know if ie works well enough to do that)

Monitoring, split the incoming video with a da, pico has some dual and fairly reasonable, feed one to the Marshall's and one to Myth. I prefer the 350, one per machine, and how many vcr's can record more than one source at a time (multiplexing not included). How many pases does a vcr tape last? How much time is spent cleaning machines? If you are using consumer vcr's, how many do you throw away each year? How long do you need to store the recording? If you can afford 15 then you can afford 16, one for a spare .

There is no such thing as real time with a dvr. Even the big boy machines have an in to out delay but typical I see with Myth is about 2 ~ 3 seconds. also it is tricky to get continous video "pass through" because once you leave live tv, you can't return.

Mike

Thanks for the post, Mike.
Actually this is for recording classes, conferences, lots of things. It's also handy when someone comes in and asks for their ancient debate video, audio cassette, 3/4", SuperBeta, whateva, to be dumped to DVD.
We have 4 distribution amps and need more. I'm not opposed to monitoring parallel to the machine, but monitoring behind the machine is best, and in 'watch tv' mode the delay is only a second which is just fine.
Your other questions wrt VHS have been kicked around by us for a long time. Nice to get some reinforcement. Our cameras are 3CCD Sonys. As they die we are slowly replacing them with Pelco 3CCD. We looked into network cameras but their audio sucked rocks and we would have a hard time routing our audio mixers into them.
When I was experimenting and had my setup with DHCP IE worked ok, but since I went static it doesn't, only Firefox and Safari. Not losing any sleep over that one.

Wanna see something cool?
ssh into your myth box, go to /myth/video, at the CLI type:
vlc NameOfRecording.mpg
We're watching The Rolling Stones from 1968 in full ANSI color on the Mac. Can't get it to work better than 1 bit color on any of the peecees.