Building a Multi-Channel PVR System? 344
Dr.Ruud asks: "What would be good ways to build a multichannel VCR? Think of a cluster of 4 PCs, each having 4 TV-cards (with MPEG-hardware on each) and (if necessary) a separate harddisk per TV-card, and maybe a 5th PC that controls the others, holds a DVD-writer and any other necessary hardware. Could it be done in a simpler and cheaper way? See also linuxtv.org, linuxmedialabs.com and of course SouceForge-vcr-projects like Freevo." What would be the best way to go about cutting down the number of machines such a cluster would need? Could this be done by building an all-in-one-wonderbox without it getting really expensive?
Eh? (Score:4, Insightful)
Re:Eh? (Score:3, Interesting)
Yeah, a video server for community tv stations. (Score:5, Informative)
I've been working with MNN [mnn.org], the public access station in New York, NY in building a cheap, open source video server out of an old TiVo [mit.edu]. The equipment necessary to program and run television broadcast/cablecast centers is often expensive and proprietary. And unless you do web playback like indymedia [indymedia.org] or freespeechtv [fstv.org], you have to buy the equipment to play the game.
An open, Linux-based multi-encoder like this (accompanied by an open video server) would do wonders for the community media world!
Retro surfing!!! (Score:2, Insightful)
So as you surf around and you see something you like, you could rewind to the begining of the show.
I have Tivo now, and often I will turn on the tv and realize that the show that is currently on, is one that I wish I had seen from the beginning. Since my Tivo was on that station, I can rewind a half hour back in to the buffer, but when I change the channel each channel doesn't have a buffer, so I'm for those I am out of luck. 16 tuners all being recorded would fix that problem
I could use something like this because... (Score:5, Informative)
If you want to edit video on a computer, you need to "digitize" or "capture" it to the computer. Hook up multiple VTRs and capture multiple tapes at once. There are systems that exist to do this, but they are high dollar. This might not be cheep, but I'm sure there would be some free clock cycles to use.
Say you do a political talk show. You want to do all the research you can. The major networks all have good political shows on Sunday morning. With this you could record them all and watch them later. Yes you could just use VCRs, but that applys to ALL PVR applications.
Many public access stations are actually multiple channels. PEG (Public, Educational, and Government) is the standard for Local Access pretty much. You could record the station live from the past so many days and stream it online to catch recent programming.
Say you have a large tape archive (the station I work at has beein archiving for under a month and has over 300 tapes) and want to store in a digital media. You could use the captured video either to make DVDs or store in low-res on a server for preview. With IDE RAIDs becoming less and less expensive, a terrabyte fileserver is now an option in the four figures.
And thats just what I can think of off the top of my head...
Re:Eh? (Score:5, Informative)
There, three reasons, at least one of which will appeal to most people.
Re:Eh? (Score:2, Insightful)
TV sucks.
Re:Eh? (Score:5, Funny)
Man, I loved that show! [imdb.com]
hmm (Score:4, Interesting)
This would mean you'd have a maximum of 4 hard drives, unless you buy an IDE card that lets you support more, wouldn't it? (Each IDE chain can have only two devices, right? or is that outdated info now?)
An interesting idea for certain though...
Save data before it is decoded (Score:5, Interesting)
Same idea for for HDTV, except save the data stream.
Re:hmm (Score:3, Interesting)
Re:hmm (Score:2, Informative)
Re:hmm (Score:2)
Re:hmm (Score:2)
16-channels at once? (Score:3, Interesting)
Personally, I can't help but think that 4 cards capturing at ideal quality would saturate the PCI bus unless each card directly controlled a hard drive.
Re:16-channels at once? (Score:5, Funny)
Basic digital cable provides different premium services... there are 6 HBO channels, 4 Cinemax channels, 4 Showtime channels, and a couple of 24-hour pr0n channels.
Obviously, the poster's intent was to record more porn. This drive for increased pornography consumption has inspired such innovations as the light bulb (for reading porn), the telephone (for listening to porn), and of course the cotton gin (for making more tube socks).
Re:16-channels at once? (Score:5, Funny)
Oh shit, I didn't realize that.
Okay okay okay okay.. lemme think.
Okay, I can help him, but I'll need sample videos from him to perform anal...ysis on. (sorry about the pause there, was distracted for a moment.)
...you forgot Vaseline (Score:2)
Re:16-channels at once? (Score:2, Funny)
Most any opject has an MPFP rating... take a toaster oven for example... its obvious that the faster you can heat a hot-pocket... the faster you can get back to one of the 16 hard core porn streams that you had recorded.
Imagine the MPFP rating of a fully reclining office chair... Unthinkable!
Re:16-channels at once? (Score:2, Funny)
Re:16-channels at once? (Score:2, Funny)
Re:16-channels at once? (Score:3, Interesting)
32bit, 33MHz PCI is 105MBytes/second. Most PCs have this, which is not capable of even supporting one uncompressed card. Of course, for this reason, TV cards do compression.
DVD quality video is 9 Mbit/sec. Assuming the encoder on the card is not as good, you can get plenty good video at 10-12mbit/sec. And you can fit pretty much as many of those onto a PCI bus as you have slots, I'd think, if the software is decently efficient and supports it. Likewise, this is pretty slow compared to typical disk I/O rates, assuming you do some buffering to allow decent-sized writes to occur and aren't seeking all the time.
Re:16-channels at once? (Score:2)
Where do you get 32 bits from? Heh. Best I've ever seen is 24, but you could easily drop that to 16 and nobody'd ever know better.
Other than that, you're right. Personally, though, I'm not a fan of MPEG2. Besides finding a player for it, it's not as efficient as say MPEG 4. I'd prefer to have the CPU do the compression in real time. One of these days I want to put together a dual-processor PVR just to do that. (The other processor is for viewing the footage on my TV without interrupting capture...)
Re:16-channels at once? (Score:2)
Re:16-channels at once? (Score:3, Informative)
Think Hotel scale TiVo. (Score:3, Interesting)
Well, that, and selling and servicing it in a scalable fashion to hotels that aren't terribly interested in giving you much of a cut.
Not a bad idea, but you run into trouble with the marketing and the amount of time you need to keep things vs. your affordable drive space. Not to mention the copyright issues the networks will come up with.
Re:16-channels at once? (Score:5, Informative)
Jeroen
Re:16-channels at once? (Score:2)
If you're interested, check out Loronix [loronix.com] who have had multi-feed stacked systems out for years.
Re:16-channels at once? (Score:4, Informative)
Total cost without the cameras and cabling, about $375. No video card needed after install, and you can get away with very little CPU power. A K6-2 350 with 32M of memory and a slow WD 2G drive is what I used to figure out if it was going to work, and it was able to deliver 2fps from three cameras and do the encode pass in under 20 minutes with 512x384 16bpp images.
And the answer, again, is "MythTV" (Score:5, Informative)
Far more interesting is what ramifications (if any) are there to having 2/3/4 tuner cards in one PC. After all, each tuner card probably needs its own sound card... what else is involved?
Re:And the answer, again, is "MythTV" (Score:3, Informative)
Re:And the answer, again, is "MythTV" (Score:3, Insightful)
Re:And the answer, again, is "MythTV" (Score:2, Informative)
i think cards that outputs directly compressed streams (such as dvb-s) doesn't need tricks like this
Why do you want it (Score:4, Interesting)
I've also never figured out why you need the DVD burner. With so much disk in my Tivo, there is always stuff to watch, and my need for archiving stuff to watch again later is so small as to be unimportant. If I _really_ need it, a lot of it is at the video store for rent.
Is the 16 tuners so you could have a box shared by a whole LAN of people? I guess if you have the bandwidth that would make sense.
Right now the public thinks PVRs are too complex, so the big vendors will probably be working to make them simpler rather than more complex.
What we really need is a component architecture, with lots of little pieces, all with 100mbit ethernet (firewire and USB 2.0 are too "smart" for their own good. ether is the
way to go.)
Then just add what you need. Tuner boxes (OTA, digital or satellite as needed.) Decoders, mounted right on the inputs of the TV that plug in ethernet and spit out component video or NTSC. The ethernet of course leads you to drives running NFS or SMB, and an always on processor to control it all that's simple.
That way you can start simple, with just a tuner, a decoder and a controller (these 3 might be in the same box) and a networked drive or a drive-in-a-box, and add what you want.
Re:Why do you want it (Score:5, Insightful)
A couple thoughts off the top of my head:
Really folks, when someone asks a question they don't want to be told why they don't need to know the answer. So, come on, don't send off-topic replys about how pathetic or dumb a question is post a constructive answer!
Re:Why do you want it (Score:3, Interesting)
In this case, of course you are going to have to do custom work because so few people would seem to need it. I could I could imagine a campus dorm, but even then 16 tuners would be too many.
(One reason for that is that so many of the shows you watch these days are repeated many times. Since with a PVR you don't care when you watch, many 'conflicts' aren't really conflicts, though the software could be better about this.
In fact, only the major networks seem not to repeat a lot.)
Now a more interesting project would be to build a receiver that could record all the closed captioning from all the channels. While you could do that with tons of tuner cards, it seems that there should be an easier way to do it since all you really want is that low bitrate VBR.
I wonder if you could do something with GNU Radio to get those VBR data streams from multiple channels at once? With enough CPU you could use GNU Radio or other software radio to do the multiple channel recording too.
Re:Why do you want it (Score:2, Insightful)
But certain days on primetime, there's like 7 shows I'd like to get a handle on to watch later, e.g. a slow weekend, the other hours of the day. Primetime plus ratings seasons equals a LOT of overlap of shows I'd to catch when *I* have the time.
For example, I liked watching Monster Garage, Mon 8pm on Discovery. But there was, for a time, Lofts on HDTV from 8-8:30. And I think Courage was on a 8pm for a while there. If you were a Third Watch person, as I was for a bit, that was on at 8pm for a while there.
Or Jag on CBS and Buffy on UPN, Tuesdays at 8.
Yes, a lot of TV if you're going to sit there and watch it that week. But given how TV runs, there is a lot of crap time, starting first with the other 18 hours of the day, and rerun season is pretty boring. Maybe I want to watch TV when I want to, not when the networks want me to.
I've only got extended cable. If you have HBO and some premium channels, there's potentially more.
Yes, the vast majority of stuff on TV is crap. But there is stuff on that's enjoyable. I use a PVR to REDUCE the amount of time I spend in front of the TV channel surfing, waiting for the show to come on, keeping track of what show switched to what time slot (SciFi bastards) or cancelled (Fox bastards).
Re:Why do you want it (Score:2)
Some people feel some sense of accomplishment by owning huge archives of "stuff". For exmaple, we probably all know people that brag about having a 100GB of music files (MP3/Ogg). But when the majority of that collection is crap they don't even like, you've got wonder, what's the point?
Re:Why do you want it (Score:2)
I know children are different so if I had those I could see having recordings for them, or more hard disk space on a networked box.
Re:Why do you want it (Score:2)
Well for a start if you had multiple tuners you'd fill up a lot more disk space. Don't forget that TV schedules are still very time-oriented so that similar programs are broadcast in "parallel". Currently you tend to pick and choose; with a multi-tuner setup you can have it all available on time-shift so you'll tend to eat up (even) more disk space.
Also, some programs are not available on DVD/VHS but you do want to store them for longer than a PVR will. A lot of (for example) home improvement shows like This Old House are useful to archive long term - if you're into home rennovation - but aren't easily available on VHS or if they are would cost a fortune to buy. I'll take a DVD burner option on my TiVo please.
Right now the public thinks PVRs are too complex, so the big vendors will probably be working to make them simpler rather than more complex.
I agree, but here's the rub. Having more than one tuner makes a PVR simpler to use not more complex. I want to be able to tell my PVR to record programs X, Y and Z regardless of when they are on. With only one tuner I have to manually resolve the conflicts when they overlap in time. Companies like TiVo (and I assume ReplayTV) have done a pretty good job of building UIs for this but its still the single most complex and confusing part of using a PVR - perhaps aside from initial setup.
Sometimes more complexity of the technology leads to a simpler user experience.
Re:Why do you want it (Score:2)
And a lot MORE of it, particularly the really GOOD stuff (as opposed to the stuff they WANT to rent you), isn't at the video store, and never will be.
I can definitely see a use for at least a couple tuners. If you're going to go, go all out, I guess.
I'm still stuck archiving to CDR, so what do I know...
PVR Advice... (Score:5, Informative)
16 channels? Err. Okay. If you really want to capture that many at once, you'd likely be better off having one computer per card. You don't need expensive/new hardware to do that. If the card does the processing and funnels the compressed data down to the hard disk, then the processor is little more than a manager. Last I checked, a P3 500 would easily handle a PVR card with hardware compression.
If you have space considerations, go with a dual I suppose. But I wouldn't do more than 2-channels per PC.
Re:PVR Advice... (Score:2)
Insanity.
I'll hazard a guess that such a "low-end" machine would have no trouble managing 16 MPEG streams, if you can find some way to plug all the hardware in.
I mean, this isn't rocket science: Video enters tuner card. Tuner card handles MPEG compression, and produces something less than a 10mbps bitstream. Multiply by 16, and we're up to - wow - something less than 20 megabytes per second.
Even once one includes requisite disk-shuffling, 40 megabytes per second of IO on a machine dedicated to the task is not a very demanding situation.
But it's not easy or cheap to squeeze more than 6 PCI cards into commodity hardware. So, we're probably limited to 6 tuners per box, which amounts to something less than 15 megabytes per second of IO.
I've got a P133 here which has no trouble pushing a paltry 15 megabytes per second around on the PCI bus. And, though I haven't checked, I can't imagine it having much difficulty achieving those rates alongside the overhead of software RAID (which is probably quite desirous for this application).
Therefore, I submit that nearly any PC hardware still available for purchase today will easily sustain the throughput required to service as many MPEG encoders as will physically fit inside the machine. I welcome corrections to my submission.
Re:PVR Advice... (Score:2)
Because you're not maxing out the processor at 500mhz, let alone 1.6ghz. But even at 1.6, processes have a way of stepping on each other's toes and causing lag. Since the video needs to be captured in real time, this lag can cause problems with the video. I know, I've had this happen.
A better threading model would be nice, but the simplest solution is to have multiple independent CPU's each with their own resources. I know this from practice, not from theory.
Some limitations to keep in mind (Score:5, Informative)
Many of the PVR cards use the KFIR encoder chip in conjunction with a Conexant bt8x8 video capture chip. The bt8x8 does the NTSC->PCM, and sends it to the KFIR encoder, which sends the MPEG data back to the bt8x8. The limitation comes from the fact that there is no hardware-assisted DMA for the data coming from the KFIR chip. That means the host process has to repeatedly poll the PCI memory address for the bt8x8 GPIO ports in order to capture the data.
Putting more than one or may be two of these cards in a single machine would swamp the machine so badly it wouldn't be able to do much else at all, let alone sending the video to disk or a network-attached storage device.
If you can find a PVR card (supported under Linux, good luck putting multiple *anything* in a Windows box) that doesn't blow the PCI bus to pieces when capturing, and you should be able to put quite a large number in a single machine, limited by PCI slots. The KFIR chip captures up to 12Mbps, which is 1.5MB/sec. PCI can peak at 132MB/sec, so as long as busmastering overhead across a dozen cards isn't fatal, you could put them all in a PCI expansion cage on a single machine.
Re:Some limitations to keep in mind (Score:2)
I may be wrong, but last time I checked, I thought that video4linux cards didn't necessarily support the level of hardware compression available on some cards.
There's a question in and of itself: Which TV output/recording cards work well and quickly? With the low cost of various cards, would it be advisable (possible?) to reserve one for recording and another for playback
Re:Some limitations to keep in mind (Score:2, Interesting)
no hard drive or raid array on a PC can do that and no network can support that without using the PCI bus.
motion.sourceforge.net sounds like a better idea.
TV Listings? (Score:3, Interesting)
I've seen the software to do it yourself and also machines that also do it (but aren't the TiVo service).
TiVo calls up a number every night and gets the listing information, is there a way to get that for the free programs and/or other machines?
I know that TV Guide has a web page with the listings - do they have an XML stream that you can grab and parse - or someone else?
If so, I'm not exactly a power user of TiVo and that would be a nice thing to have - but I don't want it as just a VCR sort of thing where I have to manually tell it "record XYZ at 4pm every thursday" - I am spoiled by the listings intelligence that TiVo has.
If there is something out there like that, esp avail over the net, that would be a lifesaver when I move to Bermuda since they don't have TiVo there and I would love to have that or something like that there.
Re:TV Listings? (Score:2, Insightful)
Re:TV Listings? (Score:3, Informative)
TV Listings are available for do it yourself PVRs.
If you're willing to screenscrape, you can use XMLTV [membled.com] to get your listings. The only potential problem is that if lots of people start screenscraping the free web sources are likely to try and stop people from doing so.
If you're willing to pay for the service, you can use TVNow [unihedron.com] and pay $30 per year [tv-now.com] (about $2.50 per month, a fraction of what Tivo charges).
5 PCs?!? (Score:5, Interesting)
But anyway, I personally would think that you would only need two or MAYBE 3 streams at once, but if you already have software to address more than one card, why stop with just two? As long as the hard drive and PCI bus can handle it, you're set.
Possible Hack (Score:4, Interesting)
Why not... (Score:2, Insightful)
Not that you'll have trouble cutting down with the amount of utter garbage out there.
Re:Why not... (Score:5, Interesting)
Technical advice (Score:4, Funny)
2. Use the stylus to systematically eliminate programming choices that cannot be realistically maintained in the desired timeframe.
This ought to do it.
Besides the computer... (Score:2, Insightful)
Or perhaps are you capturing CCTV for archival? You may want to investigate how people do that (casinos capture immense amounts of high quality digital video for security purposes). The hardware is, doubtless, expensive, but it may give you some insight on how it can be done "on the cheap".
A cluster? (Score:5, Funny)
A Beowulf Cluster of PVRs? Sweet!
Open Source PVR is not as simple as people think (Score:5, Insightful)
Every month or so, someone comes up with a newfangled linux PVR and posts it here and on sourceforge.
Last I looked, there were at least 4 seperate projects on linux PVRs. There was also something major wrong with each project!
One project has a cool interface but could not actually record!
One project could record and playback, but not record and playback at the same time!
Yet another project could record and playback, but even the author of the thing reported that the audio and video were badly out of sync.
Now: I don't know if the Ask slashdot question was a troll, or someone hoping to startup a dumb dot bomb that re-sells TV signals, but even a single P-1Ghz with an ATI all in wonder could barely record at broadcast quality - read: It didn't ever fully approximate broadcast quality.
I've got two coworkers who purchased PC PVR solutions, and guess what - all three of us now own: Tivo, Replay, and DishNetwork-PVR systems.
BAH. This is really stupid. Until someone hacks together something that actually works, and doesn't require a PHd in driver hacking, and syncs the audio properly, and has a 1/10^6 chance of working on someone else's build of linux/hardware, then let's not waste time discussing the *neato* applications of linux PVR. It's still a fantasy for private/OSS projects...
Re:Open Source PVR is not as simple as people thin (Score:5, Insightful)
Chill. Relax. There is no need for longwinded rants with random bold words. No, the free software PVR projects are not ready for prime time yet. It shouldn't be suprisingly, they're all very new. Mozilla's few few years weren't terribly promising. Linux itself took many years before approaching general usability. For the software to reach a polished stage we need to start with the crappy first pass. There is lots of experimentation and playing around. Core components (like drivers to TV cards and MPEG encoders) are still early in the development stages themselves. Eventually things will settle down, all but a handful of projects will fold, and things will become ready for you. In the meantime, let other people do a little harmless cheerleading. We need early adopters and fans to help work out the bugs in the system, do development, and keep the developers inspired.
(If you feel a burning need to emphasize something, the <em> tag will generally give you a more subtle, easy to read result. Bold text tends to leap out, dominating the paragraph. If you really want readers to just focus on those key points, consider a bulletted list using <ul> and <li>)
So, 3 years down the line... (Score:2)
Yah, it all makes sense now.
I have often thought that BeOS (Score:5, Interesting)
I talked to some developers over at BeBits about the idea; one said that he had no interest in updating any of his Beos apps and that he had entirely moved over to Windows. (ugh)
The other was intrigued, but had far too much stuff going on already.
Any ideas? Anyone thought this too? I would dive on in, but I am a musician and left programming behind with Apple II basic...
P.S. Trolls: Oh yes, Beos is dead, what am I thinking, I should learn to code, I smell like cats, blahblahblah.
Next week on Ask Slashdot... (Score:5, Funny)
Ultimate TV (Score:2)
One-channel-first, please? (Score:5, Insightful)
Word to developers - what you've done so far is great, but if you want to unseat MSFT, you've gotta make it so that Grandma can install it.
If we were talking about a new version of GCC or the latest kernel, with Visual Studio.NET and Windows Longhorn as the competition, it'd be fine to moderate this comment as (-1, Lazy n00b), but you're talking about a glorified VCR, and you're going up against TiVO.
For this kind of product, User Interfaces matter. Saying "RTFSource", and "It's skinnable", won't cut it.
Likewise, dependency trees can be a formidable barrier to adoption. Saying "Well, of course it compiles fine for me, I mean, who doesn't rebuild XFree86 from the CVS source tree on a weekly basis?" isn't gonna cut it either.
PCs are cheap enough these days, especially since folks in the DIY segment might want to dedicate one as a PVR. Given the appliance-like nature of such a device, I'd say a (set of, for each supported motherboard-chipset/video-chipset combo) binaries ought to be a design goal, and I might even go so far as to say that distribution as an ISO wouldn't be out of the question.
Re:One-channel-first, please? (Score:3, Insightful)
Word to developers - what you've done so far is great, but if you want to unseat MSFT, you've gotta make it so that Grandma can install it.
Am I not the only one who absolutely hates these patronizing comments? They are just so typical from users of free software that wish to contribute nothing yet do nothing but pester for features. I take it the above poster has posted many a time to developer lists or developer IRC channels the "HELP! IT DOESN'T WORK" posts without reading any of the docus or anything.
Well, here's a bit of a news flash: OS developers do not give a rat's ass about unseating MSFT (why you have to use the stock symbol, I do not know). We like to code! That's it. For most of us, it's not any kind of religious thing. Sure, we want people to use the software and benefit from it, but we personally care less if Grandma (or you for that matter) can install it without doing any sort of due diligence.
User Interfaces are a myth. The Windows interface is only intuitive because they give you no other choice than to learn it. OS developers give you an option not to use it, and you bitch because it doesn't behave exactly as MS's version does. If you really care, either 1) do it yourself or 2) send someone else money to do it if you don't have the skills.
BTW: As far as I'm concerned, mocking script kiddie speak is just as bad as speaking it.
Maybe I just like being simple, but.... (Score:2)
CPU Power (Score:2)
My 1Ghz Athlon is at 80% encoding HALF-frame video into MPEG4 and it drops seriously large numbers of frames if I try and encode at the native resolution (720x576 for UK PAL).
I tried using MPEG2 but that uses up seriously massive amounts of hard disk space, just to get it up to VHS standard.
Unless someone makes a hardware MPEG4 encoder, I can't see how you can easily encode 4 video streams at once unless they're done in a fairly low quality/resolution.
Nick...
Re:CPU Power (Score:3, Informative)
Thats what I have in mine, and it record Native just fine.
Re:CPU Power (Score:2)
You probably have a faster processor or you're happy to put up with lower video quality.
Nick...
More then one channel (Score:3, Insightful)
why would you post just that? I show a starttaling lack of imagination for nerds.
Just off the top, I can think of:
Archiving different channels takes on global events.
Perhape he is going to take 'orders' for recording, so instaed of settng your VCR, you just call this guy up and say "PLease record X for me"
Maybe he just thinks its interesting.
Perhaps he's going to hook it up to 16 continues camera feeds for security.
I'm sure some people here can think of more, and better ways to utilize this.
Record signal before it gets to the tuner (Score:2)
I seem to remember reading about a guy who was recording the signal before it got to the tuner. Then he played it back into the tuner and selected the show he wanted to watch. He had recorded all the available channels at once.
I read about this a long time ago. Probably back in the 1970s because I think it was when VCRs were coming out and the idea of recording a show was a new idea.
Re:Record signal before it gets to the tuner (Score:2)
What I am (vaguely) remembering was from quite some time ago. It was an all analog system so there was no need to sample.
Streaming video (Score:2)
Now, can anyone point me towards a decent media streaming solution for Linux please? (I'm serious!)
Thanks, Matt
so basically what you want... (Score:2)
sorry, but it had to be said.
Maybe he wants distributed capture (Score:5, Interesting)
What if he wanted to do distributed capture though?
Think about it, you have 4 machines capturing alternating frames. Machine 1 does frame 1,5,9 machine 2 does 2,6,10, machine 3 does 3,7,11 ect.
This thought occurred to me last night while doing some kazaa downloading. Maybe a better P2p capture system would involve each client downloading 1 frame per movie, and sharing that with the world. The clients could assemble the movie from a distributed network, much like a frame server does in premiere.
The real advantage to doing this would be movies that are stored in a lossless format.
Re:Maybe he wants distributed capture (Score:3, Informative)
Of course, that is deopendant of the number of users, downloading the file. And a few other things. But it is an intersting concept.
Try doing a search on google for Bit Torrent, I THINK that comes up with the best results.
- Ice_Hole
Re:Maybe he wants distributed capture (Score:3, Informative)
i'm downloading something from torrent right now. 1394.1 MB, it was slow at first, but now i'm steady at around 22kb.
Thing thats cool about BT is it's very easy to become a seed node. I d/l the FBSD 5 iso's from a FTP source before finding the BT source. Since i'm such a nice guy I shared my ISO's simply by clicking the link on the FBSD BT page and saved it where my previously d/l iso's were. Whammo I was a BT seed for 24hrs.
sigh (Score:2, Insightful)
I've seen a lot of threads that say an application like this would be great for security cameras and the like.
Assuming this is even implementable (which it is not), lets look at a cost breakdown:
16 video capture cards - $100 x 16
16 120 gig hard drives - $120 x 16
4 cheap cases - $50 x 4
4 mb/proc/mem combos - $240 x 4
1 dvd burner - $200 x 1
other odds and ends - $100
which comes out to a grand total of approximately, oh, $5000
Now lets look at my solution:
16 VCR's purchased from circuit city- $50 x 16
one guy to switch tapes every six hours- $6.50/hr
$806.50.
I dunno if it is possible but.. (Score:4, Insightful)
But this is what I propose. You would have to get a card that is modded to recognize these blocks of channels (They all recognize the channels, but they won't recognize the individual digital channels, unless they are digital cards). BUT, take these cards, and record the 6mhz bandwith, NOT the actualy individual channels.
Lets put it this way, lets say HBO runs at the 550 mhz - 556 mhz range (Which is arrpox where it is for COX Cable Las Vegas) If we were to recorde this range, we would not just be getting the normal HBO that we want, but also all of the other channels on the same bandwith. On average thir are 8 high quality streams on any 6 mhx channel. So in this case, by recording one of these channels, we would be able to extract 8 channels, say HBO, HBO2, HBO Signature, HBO Latina, Cinemax, etc.
In this case, it might be able to record between 8 and 40 channels per tuner card. With specially modified hardware, and software to do this level of decodeing.
Also if you were to find a way to compress this data, you might be able to find an extremely efficient way to compress this data.
- Ice_Hole
see... someone listens (Score:2)
You all kicked my ass but see... He listened.
A waste... (Score:3, Funny)
A PVR that can record 16 channels at once? Get real. Unless you're operating a TV station, you don't need that many channels. And if you do operate a TV station and you're asking Slashdot how to build video equipment - you're fucked.
Here's a tip kid. Quit jerking off thinking about recording 16 TV shows at once and go outside.
[And yes, I've got Karma to burn.]
MythTV (Score:3, Informative)
Hmm... how much are you willing to spend? (Score:3, Informative)
Given enough money, anything is possible.
If you want to reduce the number of nodes, you need to increase the capacity of each individual unit. One way of doing that would be to use a PCI backplane with a motherboard "card". This would give you more than the 4 or 5 PCI slots on most motherboards.
Go with a FireWire or USB2.0 capture device instead of a capture card. You can connect 4 capture devices to a 4-port FireWire or USB2.0 PCI card. So, if you only devote 3 PCI slots to your input sources, you still get between 6-12 concurrent input streams via FireWire or USB2.0. The problem is finding a TV tuner you can control via software through the FireWire and USB2.0 links. But that would solve your problem of recording alot of different shows at the same time with fewer CPU count.
If you plan on having the storage local, you'll want to go Raid. Hardware Raid would be better than software Raid.
If you use a seperate machine for storage, I'd go with NFS or netcat over GigaEthernet to a FileServer with striped volumes on mirrored or Raid-5'd disks. netcat would be better since it has lower overhead than NFS.
So, with 2 Computers, you will be able to capture from 1-12(depending on how many cards and ports you use) individual channels/sources to a very fast file server which can then serve out the streams or burn them locally to DVD(s).
ADC, Canopus, Sony, and a few others produces AVFireWire/USB2.0 adaptors, but they are for signal source and output and not for tuners/channels. Some resources listed below:
Resources
WinTV Products:
http://www.hauppauge.com/html/usb_data.htm
A USB TV Tuner
http://www.snapstream.com/buy/buy-tunerusb.htm
More USB TV Tuners...(wintv repackaged)
ATI Wonder USB
http://www.ati.com/products/pc/tvwonderusb/
http://shopper.cnet.com/shopping/resellers/0-114 36-311-3850079-0.html
ATI usb tuner card...
Basically, they are USB tv tuners which captures to MPEG1 or MPEG2... if you're running under Linux anyways, you can re-pipe through Mjpegtools to resize and recompress to MPEG2 format for use with DVD playback on the fileserver.
But yeah, it's doable. :)
Good luck and have fun!
Activism (Score:2)
One way, perhaps to speed this transition, which I would consider a form of activism, would be to set up such a grand TV ripping station and every week let's say, burn a few CDs/DVDs for different types of people. A disc of cartoons, some friends are mine are into sports so we'll burn one for them too, and of course the news, and C-SPAN and whatever else we feel like. Not to mention of course, all the movie channels.
This would of course, be highly illegal and expensive and make no money, but I think it would be a grand gesture in the fight against intelectual property. Cheers, Joshua
Record the RF (Score:2)
Use Canopus Boxes And Firewire Cards (Score:5, Informative)
Also, I am curious why you would want to use MPEG encoder cards to record your video. If you've ever tried this, you would quickly realize MPEG is a REALLY bad format to use if you plan on editing your video. I assume you will be editing your video right, I mean who and the hell would want to burn TV programs, commercials and all, straight to DVD with no editing. Anyway, editing MPEG video, no matter what you use is a bad proposition.
My system, which is two low power PCs with various large (300GB+) multidrive RAID arrays, firewire cards, 1 Canopus ADVC-100 on each system and Sony Satellite receivers. The Sony are important since they have a 9 pin serial connector which connect directly to the PC for changing channels and controlling the satellite receiver.
This system works flawless and I have recorded around 1,500 TV Shows since late 2001. My Linux based recording solution prior to this was moderately reliable but the quality was not good enough for DVD. With this setup the quality of the burned DVDs are almost indistinguishable from the broadcast source. In other words, very good. Oh by the way, my interface for scheduling is custom web interface using Mysql for storing data.
Now I suppose if you were hell bent on it, you could put multiple cards in a few machines and run multiple capture processes to grab your insane 16 channels, but that would be one busy machine. I would recommend a more sensible soultion, one like mine would probably work nice.
My setup includes 2 machines for grabbing video straight to disk in DV format (very high quality, does not degrade with editing like other lossy compression methods). Now these machines also double as mpeg encoders too, but don't do much else. They stay pretty busy with just those two tasks. I have another 3 machines that are dedicated MPEG encoders, using mjpegtools as the encoding software. My desktop machine is where I edit the video, using Kino. I also use my desktop to run dvdauthor, which masters the DVD-Video folders prior to burning them to disk. This machine sometimes encodes MPEG too. On some days I have as many as 6 or 7 MPEG encoder machines going. And I have yet another machines that actually burns the DVDs.
So I guess you could do it with a few machines, but you'll be sorry once you've got a bunch of video to encode or master and only a few CPU to do it. Make your capture machines the cheap, slow CPU type and your encoder, editing, mastering machines of the fast type and you might be all right. I'd still love to know why you would want to record 16 channels. Also, I assume you are doing this with Cable TV, which sucks for quality and regular cable too, since digital cable requires a box for each individual channel you need to watch at the same time. I can't see anyone paying for rental on 16 cable boxes. Even worse I can't see anyone spending that much money on 16 satellite reveivers. I have 6 satellite recievers and I almost cried when I had to pay for them.
Oh by the way, my system is 100% Linux end to end, so the poster who posted a comment above who says there is no Linux PVR solution that works, has no idea what he is talking about.
-Aaron.
My way? (Score:2)
here's the only problem, how do you capture from three seperate sources at once? Maybe you could rig the ATi multimedia center to run several instances each pointed towards the different capture boards? Maybe ditch windows all together and find a linux solution?
Lay off (Score:2)
Unfortunatly it turned out to be cost prohibative at the time (2 years ago) and we just fell back to a bunch of samba shares and watching TV on computer
which hardware card? (Score:2)
Has this guy watched TV lately? (Score:2, Funny)
An array of PVR's? What in the world are you going to watch? There aren't enough good shows on on to keep a single PVR busy let alone an array of them.
Me? I'm going to build an array of vacuum cleaners. My idea sucks too, but will cost less.
DV-to-Firewire? (Score:2)
The camcorder provides the video stream in MJPEG format (which would probably need to be reencoded to something a little more standard, but that could be done at leisure and perhaps other machines).
If you've got a powerful-enough PC, it should be able to handle a couple of simultaneous Firewire streams. There's probably some way to do the video/audio->Firewire conversion w/o a camcorder too. There might also be video/audio->USB converters (as long as your USB connections have a high enough bandwidth to handle a decent quality stream).
Anti-TV Religion (Score:4, Interesting)
What is it with this anti-TV religion that some people seem to have joined? It's not just that they don't watch TV, they insist that nobody else should watch TV either. If you watch TV you're an inferior person! They interrupt conversations to make sure that everybody knows they don't watch TV. They are insanely PROUD of the fact that they have never seen an episode of Farscape, or didn't watch the 6-o-clock news last night.
At what point did "not watching TV" become such a huge achievement for these people? Is there a similar group of anti-readers? Imagine some nutjob interrupting a conversation about an Asimov novel to make it clear that he never reads novels and in fact doesn't even own any novels! You'd rightfully think a person like that was mentally deranged, yet this bizarre behaviour is proudly proclaimed when the medium is television.
To all you idiots repeating the tired mantras of "I never watch TV!" and "You TV watchers should get lives!", I say that you are the people without lives if you think not watching TV is some sort of achievement.
Re:PC Stereo Component (Score:2, Informative)
Re:PC Stereo Component (Score:2, Informative)
I like my Cooler Master ATC-600 [coolermaster.com], but it looks like they have a number of other options [coolermaster.com] as well (look under "Desktop"). The ATC-600 is just slightly too big for my entertainment center, but it perches nicely on top of it. Now I just need to find a reason to use the thing (now I have a high definition cable feed, the HTPC is useless for recording shows). Also, it's a Micro-ATX form factor, but if you're planning on doing an HTPC, that should be more than enough. Especially if you want the case to fit well in your entertainment center.
Re:PC Stereo Component (Score:2)
It'd be a little bit harder if you want to do both sound and video, but I'm pretty sure you could get a pretty Cobalt box with multiple slots.
Unless you're doing something nasty, a 500MZ processor should be more than enough for most work.
Re:Hmmm.. (Score:5, Informative)
If that is the case he should have a look at motion [sourceforge.net] it can handle multiple videodevices and even use multiple inputs on each device.
Jeroen
Re:Hmmm.. (Score:2)
On the moon? I can hear it now:
"And the winning team will receive training on how to extract oxygen from Moon rock. To the loosing team, training on how to go into a low metabolism trance. John, JOHN. Quick someone share an oxygen bottle with John. HURRYYYYY.....".
Re:Use PiP functions to half the number of cards? (Score:2)
Looks like it only has one tuner.
Re:No doubt... (Score:2)
Considering the number of times HBO reruns things, you could probably get every show with only one recorder...
Re:Replay TV would be a lot cheaper and better (Score:2)
http://www.titantv.com/ttv/programming/Search
parse the results and download the