Not as simple as it looks - Re: Build It Rolling Your Own Tivo(fwd)
An example from my day yesterday... I have two 'cheap boxes', one from nation wide chain store (who sells things other than high tech and appliances, a wall to wall mart if you will) and one from a local Austin vendor. The behavior was checked against multiple instances of boxes so we know it isn't a single bad box. Each machine has all the normal stuff, 1G of RAM, 2x80G HD. They also include an AGP video card, PCI video capture card (no tuner, commercial quality board), and a PCI 10/100M Ethernet. Running under Linux using various Open Source tools. We used different AGP and network cards to verify brand dependence. Different brand board for AGP or network made no difference. We couldn't try different video capture boards due to cost, we had a single board. One of the boxes works fine. The other drops frames if the network traffic gets too high or you really push the video board. It doesn't drop much, down to about 27fps from 30fps, but it drops. And at the same time you get digital aliasing [1], which is the real killer. Pull the AGP or network (usually the network because we like the pretty pictures) and all is fine (though w/o network it's a little annoying). Why? The interrupt controller on the slower box isn't up to it. I have a similar project under Plan 9 where I'm trying to take four of these cheap-ass television cards in a cheap-ass box and export them into a namespace so you could at least in principle watch television from just about anywhere. The video frame is limited to 320x200 (for several reasons I won't go into here). And those babies drop frames for this same reason. I will grant that video support on Plan 9 is down right pre-historic so some improvement may be gleaned from re-doing that (I hope so or else we'll drop this as infeasible at this level of tech). So, no, setting up a -quality- video capture system isn't easy or mundane on expensive systems and certainly not cheap boxes. But then again, you may not even notice the aliasing or dropped frames. That you don't notice the jitter or blocky display speaks to you, not the technology. Which is -not- to say it can't be done, I see from 3-5 of these sorts of systems a month built that work fine. But it does take time and effort, it is -not- plug and play. Also be prepared to tweak the television drivers for Linux since they are seldom optimal. [1] This is that 'blockish' effect you will see on a lot of television shows now because a lot of them are moving to non-linear video editor suites, it occurs when the conversion process stalls a bit in frame. It comes from the machine not being able to keep up and update the field completely so you'll get the even or odd field but not both. Clouds are a really good place to look for this effect. -- We don't see things as they are, [EMAIL PROTECTED] we see them as we are. www.ssz.com [EMAIL PROTECTED] Anais Nin www.open-forge.org
Re: Build It Rolling Your Own Tivo (fwd)
On Sat, 7 Dec 2002, Jamie Lawrence wrote: > > On Sat, 07 Dec 2002, Lucky Green wrote: > > > It never ceases to amaze me that there are subscribers to this list that > > don't have Choate filtered. This must be some weird list to read without > > a Choate procmail filter... > > Yes, my mistake. I've seen Choate devolve from a strange actor to a > net.loon, and I should have known better. I thought an off-list hint > might help, and that was my mistake. I promise never again to venture > into Choate Prime. Yada yada yada...I'm still waiting for a reference where Godel equates 'undecidable' to 'incomplete' -- We don't see things as they are, [EMAIL PROTECTED] we see them as we are. www.ssz.com [EMAIL PROTECTED] Anais Nin www.open-forge.org
Re: Build It Rolling Your Own Tivo (fwd)
On Sat, 7 Dec 2002, Bill Stewart wrote: > At 11:38 PM 12/06/2002 -0600, Jim Choate wrote: > >You should have tried this back in the late 80's with a single frame VHS > >recorder and an Amiga Video Toaster...one frame at a time, thank god for > >AREXX ;) > > If you were actually using the Video Toaster, and not just the Amiga's CPU, > you had what passed for a really hefty amount of CPU-equivalent back then, > because the video crunching happened in the Toaster card, > not in the Amiga itself. The Amiga had enough work to do just storing the > compressed video onto a disk... Agreed, but the point argues to my point not against it. Thanks. -- We don't see things as they are, [EMAIL PROTECTED] we see them as we are. www.ssz.com [EMAIL PROTECTED] Anais Nin www.open-forge.org
Re: Build It Rolling Your Own Tivo (fwd)
On Sat, 07 Dec 2002, Lucky Green wrote: > It never ceases to amaze me that there are subscribers to this list that > don't have Choate filtered. This must be some weird list to read without > a Choate procmail filter... Yes, my mistake. I've seen Choate devolve from a strange actor to a net.loon, and I should have known better. I thought an off-list hint might help, and that was my mistake. I promise never again to venture into Choate Prime. And yes, Jim goes back in the spam filter. > --Lucky, who probably should go back to filtering on "Choate" in the > body text of emails, not just in the headers. I didn't even need to see > that email. Probably for the best. I'm going to sleep now. -j, who shouldn't revisit past choices on spam filters. -- Jamie Lawrence[EMAIL PROTECTED] "Crack don't smoke itself." -Traditional
Re: Build It Rolling Your Own Tivo (fwd)
At 11:38 PM 12/06/2002 -0600, Jim Choate wrote: You should have tried this back in the late 80's with a single frame VHS recorder and an Amiga Video Toaster...one frame at a time, thank god for AREXX ;) If you were actually using the Video Toaster, and not just the Amiga's CPU, you had what passed for a really hefty amount of CPU-equivalent back then, because the video crunching happened in the Toaster card, not in the Amiga itself. The Amiga had enough work to do just storing the compressed video onto a disk...
RE: Build It Rolling Your Own Tivo (fwd)
Jamie Lawrence wrote: > > > Jim, you post enough crap from Slashdot to know > differently. People > > > are doing it. I have a whitebox machine (AMD, 256M ram, cheap TV > > > card, 20G disk, $300 a year ago) that does it. It isn't a > big deal. > > > > Speaking of posting crap...and don't send me private email. > > Don't worry about me sending private email in the future... > You're not only > a complete idiot, but you're rude as fuck as well. It never ceases to amaze me that there are subscribers to this list that don't have Choate filtered. This must be some weird list to read without a Choate procmail filter... --Lucky, who probably should go back to filtering on "Choate" in the body text of emails, not just in the headers. I didn't even need to see that email.
Re: CDR: Re: Build It Rolling Your Own Tivo (fwd)
On Sat, 07 Dec 2002, Jim Choate wrote: > > No, actually, for those of us who live in the real world, it isn't as > > important as you make it out to be. > > Uh huh... No comment needed. -- Jamie Lawrence[EMAIL PROTECTED] "They [RIAA,MPAA] are trying to invent a new crime: interference with a business model." - Bruce Schneier
Re: CDR: Re: Build It Rolling Your Own Tivo (fwd)
On Sat, 7 Dec 2002, Jamie Lawrence wrote: > Don't worry about me sending private email in the future... You're not only > a complete idiot, but you're rude as fuck as well. That's funny. > No, actually, for those of us who live in the real world, it isn't as > important as you make it out to be. Uh huh... > I'm not going to tell you the processor speed, becuase that would only > egg you on. Rather speaks for itself, doesn't it? -- We don't see things as they are, [EMAIL PROTECTED] we see them as we are. www.ssz.com [EMAIL PROTECTED] Anais Nin www.open-forge.org
Re: CDR: Re: Build It Rolling Your Own Tivo (fwd)
On Fri, 06 Dec 2002, Jim Choate wrote: > > On Fri, 6 Dec 2002, Some poser wrote: > > > Jim, you post enough crap from Slashdot to know differently. People are > > doing it. I have a whitebox machine (AMD, 256M ram, cheap TV card, 20G > > disk, $300 a year ago) that does it. It isn't a big deal. > > Speaking of posting crap...and don't send me private email. Don't worry about me sending private email in the future... You're not only a complete idiot, but you're rude as fuck as well. > Which is irrelevant, what is the CPU speed of the box? -THAT- is what is > important...raw processing power. An old 486dx/80 running Linux will store > video but only at a handfull of fps. No, actually, for those of us who live in the real world, it isn't as important as you make it out to be. I'm not going to tell you the processor speed, becuase that would only egg you on. Suffice it to say, I use a cheap PC to record TV shows, with open source and a bit of custom software. It works. Well. You can continue believing whatever you like. I'm reminded of a joke I heard in college. An econ professor and a student are walking over the quad. The student says, "Look, there's a $20 bill on the ground!". The professor replies, "Nonsense. If there were, someone surely would have picked it up." -j -- Jamie Lawrence[EMAIL PROTECTED] "People should be allowed to keep midgets as pets." - Gov. Jesse Ventura
Re: Build It Rolling Your Own Tivo (fwd)
On Fri, 6 Dec 2002, Some poser wrote: > Jim, you post enough crap from Slashdot to know differently. People are > doing it. I have a whitebox machine (AMD, 256M ram, cheap TV card, 20G > disk, $300 a year ago) that does it. It isn't a big deal. Speaking of posting crap...and don't send me private email. Which is irrelevant, what is the CPU speed of the box? -THAT- is what is important...raw processing power. An old 486dx/80 running Linux will store video but only at a handfull of fps. In any real world system not only are you going to pull the raw data off the tv card (30fps@4Mb/frame@60s~=.7G for 1m of video) but also use a codec to compress it. Then you've also got to move the bits onto the hard drive. All without throwing any interrupts that will cause a dropped frame or cause a codec problem. And don't forget that's at the default television resolution (which is less than 640x480). If you want to scale it up to 1024*768 you've got a lot of interpollating to throw in there as well. And then if you want HDTV or Widescreen (Firefly in widescreen is awesome!) you've got an even heavier load. This lets you put roughly 45m of video (along with the audio) on a standard 600M CD-R (and if you want to burn the CD-R or watch the stream at the same time you're encoding it while you surf the net and handle email and run your firewall... you can increase the cpu requirements considerably). There -is- a big deal and it went right over your head. Just any old cheap box will -not- do video -effectively-. Then again, maybe you like watching 320x200. You should have tried this back in the late 80's with a single frame VHS recorder and an Amiga Video Toaster...one frame at a time, thank god for AREXX ;) -- We don't see things as they are, [EMAIL PROTECTED] we see them as we are. www.ssz.com [EMAIL PROTECTED] Anais Nin www.open-forge.org
Re: Build It Rolling Your Own Tivo (fwd)
On Thu, 5 Dec 2002, Michael Cardenas wrote: > Of course, you could do this yourself with a $199 microtel box from > walmart and linux. Then you'd just have to add a $30 tv in card. > > On Thu, Dec 05, 2002 at 04:48:44PM -0600, Jim Choate wrote: > > http://www.extremetech.com/article2/0,3973,692134,00.asp Probably not, it takes quite a bit of processing power and a good size hard drive to do it effectively. 30fps (~4MHz bandwidth per frame) is a lot of data to move in real time. -- We don't see things as they are, [EMAIL PROTECTED] we see them as we are. www.ssz.com [EMAIL PROTECTED] Anais Nin www.open-forge.org
Re: Build It Rolling Your Own Tivo (fwd)
Of course, you could do this yourself with a $199 microtel box from walmart and linux. Then you'd just have to add a $30 tv in card. On Thu, Dec 05, 2002 at 04:48:44PM -0600, Jim Choate wrote: > http://www.extremetech.com/article2/0,3973,692134,00.asp > > > > We don't see things as they are, [EMAIL PROTECTED] > we see them as we are. www.ssz.com > [EMAIL PROTECTED] > Anais Nin www.open-forge.org > > > -- michael cardenas | lead software engineer, lindows.com hyperpoem.net | GNU/Linux software developer people.debian.org/~mbc | encrypted email preferred "One evening I seated beauty on my knees. And I found her bitter, And I cursed her." - Arthur Rimbaud [demime 0.97c removed an attachment of type application/pgp-signature]
