If you're talking USB(1), then even a single "webcam" is useless for motion-capture unless you're talking about using really low resolutions. USB is just too darned slow.
As another person stated above, get some capture cards with BrookTree chips. The Bt848 and Bt878 are very well supported in Linux, and have been for many years (used to use one on a 486). The cards can be had around $50-$75 usually, sometimes as cheap as $20-$25 at local computer shows.
According to the docs for the bttv driver, the PCI bus doesn't get saturated with 4 cards, so this is probably the way to go.
Another plus is the fact that not only are these capable of much higher resolution than any USB camera out there, the signals you can pipe into these cards can be much higher quality and from a variety of sources (old camcorder, mail-order pinhole camera, DVD-player via S-video, etc.). In other words, you can use a high-quality CCD rather than a low-res/low-quality/low-light-sensitivity CMOS imager (that nearly all USB "webcams" have).
Another possible option is ieee1394 ("firewire") cameras. Anyone know if any firewire webcams (not camcorders) are supported in Linux? (I've only seen two brands, years ago)
BTW: I have an IBM and a Labtec USB webcam. While both work with Linux, both suck horribly in every category compared to my Sun Camera connected to my Bt878 card (which also contains TV and FM tuners).
Heh, you know it! I'm seriously considering megasquirting my '76 TR7! I even have the manifold, throttle-body, injectors, etc. already (from an '81/California model).
I'm on the wedge-list... there's at least one other person planning to MS his TR8 too.
Not familar with that one, but it's been a while since I researched 'em. You don't mean FCD, do you? If so, that's just a simple aux circuit that's actually quite dangerous. Probably not, by your description. Either way, how much does this cost? MegaSquirt is mega-cheap... only a bit over $100 for the kit! Plus there's the satisfaction of having built it yourself, rather than just buying something someone else mass-produced. I'm seriously thinking about using one on my TR7, TR8, and RX-7 Turbo II.
Jeez... I can't believe I'm the ONLY slashdotter who knows that what made Burt Rutan famous was his incredibly cool consumer canard known as the Long-EZ.
Of course no-one's going to see it now since two boneheads that didn't get the reference moderated the posting as offtopic.
that all the time travelers who made money on the stock market left over a year ago! Just who do you think is responsible for the tech boom and.com bust?
Anyone figure out a command line for mencoder to record from a v4l device directly to an MPEG1 or MPEG2 file with the appropriate limitations for VCD or SVCD (respectively)?
Unfortunately, this produces an avi file, with an mpeg1 layer 3 audio stream... as I understand it, a layer 2 stream is needed (not positive about that). Also, what's needed is an mpeg file format, not mpeg1 data in an avi wrapper.
The following produces an mpeg file...
mencoder -tv on:driver=v4l:norm=ntsc:input=0:width=352:height=2 40:fps=29.97:adevice=/dev/dsp:amode=1:volume=51000 -ovc lavc -lavcopts vcodec=mpeg1video:vbitrate=1152:vhq -of mpeg -ofps 29.97 -oac mp3lame -lameopts cbr:mode=0:br=224 -o myvideo.mpg...but this file ends up with no audio, even though mencoder claims it's encoding audio into the file.
Anyone know how to produce a VCD-ready (or SVCD-ready) without having to record in one format and convert/re-encode to another format before burning?
I currently have a GeForce2GTS and have tried many of the drivers from NVidia with sporadic stability (yes, I've posted to their forums... no, they haven't been able to help).
I'm seriously considering a Radeon 9100... does anyone know how stable the current drivers from XFree are on this card? Secondarily, how does the performance compare between the above two cards (under Linux)?
Yes, I do occasionnally use 3D in Linux (I don't use MS-Windows at all)... bzflag and UT mostly.
While the cost/MB is about the same, I see a distinct advantage in the smaller size.
It's easier to give a recording to my sister when it's the only recording on the disk... rather than giving her 5+ hours of recordings (by the storage ratio listed in the article).
That, and CD burners are drastically cheaper than DVD burners.
That's kind of silly since DVDs are drastically higher resolution, better sound (with more channels), etc.
VCD/SVCD would make much more sense... since VCD is VHS quality and SVCD is (supposedly) about the same quality as NTSC is capable of carrying... AND you can play them back in (almost) any DVD player. Not to mention the fact that it would be MUCH cheaper.
Yeah, I forgot about the monster cutting-plotters (I worked in a sign-shop for a while too). I was referring to the old table-top flatbed A and B size pen-plotters - the ones that either held only one pen, or some of the fancy ones that had a carousel of 4 or 6. Last one I saw was at a ham-fest several years ago... think they had it for $20 and no-one bought it. At the time, the idea of making a PCB mill out of it never even crossed my mind.
Well, there used to be Electronics Now and Popular Electronics (which merged, and became Poptronix), but the printed publications are gone (to my knowledge). You may be able to find all the old issues at your local library... although ones over 1 year old may be only on microfische.
As much as I'm annoyed with Radio Shack for turning into a toy and appliance store (they used to be an electronics hobbyist store), they do still have a handfull of items for the electronics tinkerer. I'd recommend picking up all of their Engineer's Mini-Notebooks to start with. I'd also recommend checking out some of their X-in-one kits... I think they have a 300-in-one now (I hope they haven't stopped making these). They have all kinds of example circuits that you can make by hand wiring (read: no soldering) the circuits together - and some of the examples are kind of cool for a beginner. I started with a 150-in-one kit (it was the biggest at the time) way back when I was a teen.
After this... if you want to get into digital electronics, pick up the TTL Cookbook and CMOS Cookbook by Sam's. If you want to get into audio electronics, pick up the Audio IC OP-Amp Applications (also by Sam's). If you're a musician, there's a VERY cool one called Electronic Projects for Musicians by Craig Anderton. Use this one with the above audio book to come up with some really cool guitar effect "pedals".
Slashdot Mirror
If you're talking USB(1), then even a single "webcam" is useless for motion-capture unless you're talking about using really low resolutions. USB is just too darned slow.
As another person stated above, get some capture cards with BrookTree chips. The Bt848 and Bt878 are very well supported in Linux, and have been for many years (used to use one on a 486).
The cards can be had around $50-$75 usually, sometimes as cheap as $20-$25 at local computer shows.
According to the docs for the bttv driver, the PCI bus doesn't get saturated with 4 cards, so this is probably the way to go.
Another plus is the fact that not only are these capable of much higher resolution than any USB camera out there, the signals you can pipe into these cards can be much higher quality and from a variety of sources (old camcorder, mail-order pinhole camera, DVD-player via S-video, etc.).
In other words, you can use a high-quality CCD rather than a low-res/low-quality/low-light-sensitivity CMOS imager (that nearly all USB "webcams" have).
Another possible option is ieee1394 ("firewire") cameras.
Anyone know if any firewire webcams (not camcorders) are supported in Linux? (I've only seen two brands, years ago)
BTW: I have an IBM and a Labtec USB webcam. While both work with Linux, both suck horribly in every category compared to my Sun Camera connected to my Bt878 card (which also contains TV and FM tuners).
-
All you have to do if you want to show the scientific community's interest in Linux, is to show the scientific community's use of Linux: The 500 most powerful computer installations in the world... many of which run Linux, including the the 2nd fastest system in the world (and all of which are used by members of the scientific community).
You could also use these simple searches on slashdot (here is another) and google to collect some very interesting data.
For example, here's a nice tidbit that may be the exact community you're looking to impress.
Granted, these do not give you a timeline, but it should be enough data for you to be able to ask them "Why are we not using Linux?".
Am I the only one who immediately thought of the movie Antitrust?!?
If you haven't seen it... DO SO!
Awesome flick, and 100% appropriate for this crowd.
Heh, you know it!
I'm seriously considering megasquirting my '76 TR7!
I even have the manifold, throttle-body, injectors, etc. already (from an '81/California model).
I'm on the wedge-list... there's at least one other person planning to MS his TR8 too.
Not familar with that one, but it's been a while since I researched 'em.
You don't mean FCD, do you? If so, that's just a simple aux circuit that's actually quite dangerous.
Probably not, by your description.
Either way, how much does this cost?
MegaSquirt is mega-cheap... only a bit over $100 for the kit!
Plus there's the satisfaction of having built it yourself, rather than just buying something someone else mass-produced.
I'm seriously thinking about using one on my TR7, TR8, and RX-7 Turbo II.
Jeez... I can't believe I'm the ONLY slashdotter who knows that what made Burt Rutan famous was his incredibly cool consumer canard known as the Long-EZ.
Of course no-one's going to see it now since two boneheads that didn't get the reference moderated the posting as offtopic.
Sounds too much like Salvage One... and images of flying cement-mixers spring to mind.
no... really! (read the article)
Wierdest fuel I've ever heard of!
C'mon people, this is an easy one (no pun intended).
that all the time travelers who made money on the stock market left over a year ago!
Just who do you think is responsible for the tech boom and
Please people... this all happened 255 years ago!
Yes, he DID break a law...
Specifically, the Temporal Interaction Act of 2236, section 7, part 32, paragraph A.
Look it up!
I'm sure there are other parts of the law he broke too, but IANALFTF.
Bush could name the former chief of security of Microsoft as the Cyber Security Czar... oh wait, he did.
You can't exactly test the health hazards of something that you haven't invented yet... sheesh.
...and get them to do this with Farscape!
It's a great idea... they are not completely abandoning their fans (like SciFi channel is), since the show will still be available in some form.
Anyone figure out a command line for mencoder to record from a v4l device directly to an MPEG1 or MPEG2 file with the appropriate limitations for VCD or SVCD (respectively)?
2 40:fps=29.97:adevice=/dev/dsp:amode=1:volume=51000 -ovc lavc -lavcopts vcodec=mpeg1video:vbitrate=1152:vhq -ofps 29.97 -oac mp3lame -lameopts cbr:mode=0:br=224 -o myvideo.avi
2 40:fps=29.97:adevice=/dev/dsp:amode=1:volume=51000 -ovc lavc -lavcopts vcodec=mpeg1video:vbitrate=1152:vhq -of mpeg -ofps 29.97 -oac mp3lame -lameopts cbr:mode=0:br=224 -o myvideo.mpg ...but this file ends up with no audio, even though mencoder claims it's encoding audio into the file.
The closest I've gotten (for VCD) so far is:
mencoder -tv on:driver=v4l:norm=ntsc:input=0:width=352:height=
Unfortunately, this produces an avi file, with an mpeg1 layer 3 audio stream... as I understand it, a layer 2 stream is needed (not positive about that).
Also, what's needed is an mpeg file format, not mpeg1 data in an avi wrapper.
The following produces an mpeg file...
mencoder -tv on:driver=v4l:norm=ntsc:input=0:width=352:height=
Anyone know how to produce a VCD-ready (or SVCD-ready) without having to record in one format and convert/re-encode to another format before burning?
I think that was the name... anyone else remember that TV series with the home-made rocket where the capsule was made out of a cement truck's mixer?
I think their logo was a vulture... the whole idea was they made money by salvaging space junk (or something like that, I was a kid).
$ host www.freemikehawash.org
www.freemikehawash.org has address 0.0.0.0
What's next? The articles on Wired and NYT?
I currently have a GeForce2GTS and have tried many of the drivers from NVidia with sporadic stability (yes, I've posted to their forums... no, they haven't been able to help).
I'm seriously considering a Radeon 9100... does anyone know how stable the current drivers from XFree are on this card?
Secondarily, how does the performance compare between the above two cards (under Linux)?
Yes, I do occasionnally use 3D in Linux (I don't use MS-Windows at all)... bzflag and UT mostly.
While the cost/MB is about the same, I see a distinct advantage in the smaller size.
It's easier to give a recording to my sister when it's the only recording on the disk... rather than giving her 5+ hours of recordings (by the storage ratio listed in the article).
That, and CD burners are drastically cheaper than DVD burners.
That's kind of silly since DVDs are drastically higher resolution, better sound (with more channels), etc.
VCD/SVCD would make much more sense... since VCD is VHS quality and SVCD is (supposedly) about the same quality as NTSC is capable of carrying... AND you can play them back in (almost) any DVD player.
Not to mention the fact that it would be MUCH cheaper.
I'd love to have a VCD/SVCD recorder.
Yeah, I forgot about the monster cutting-plotters (I worked in a sign-shop for a while too).
I was referring to the old table-top flatbed A and B size pen-plotters - the ones that either held only one pen, or some of the fancy ones that had a carousel of 4 or 6.
Last one I saw was at a ham-fest several years ago... think they had it for $20 and no-one bought it.
At the time, the idea of making a PCB mill out of it never even crossed my mind.
Wow!
That really sucks, they used to be great!
I guess too many companies are going Mazak.
Dunno, been out of that business for over a decade.
Well, there used to be Electronics Now and Popular Electronics (which merged, and became Poptronix), but the printed publications are gone (to my knowledge). You may be able to find all the old issues at your local library... although ones over 1 year old may be only on microfische.
As much as I'm annoyed with Radio Shack for turning into a toy and appliance store (they used to be an electronics hobbyist store), they do still have a handfull of items for the electronics tinkerer.
I'd recommend picking up all of their Engineer's Mini-Notebooks to start with.
I'd also recommend checking out some of their X-in-one kits... I think they have a 300-in-one now (I hope they haven't stopped making these).
They have all kinds of example circuits that you can make by hand wiring (read: no soldering) the circuits together - and some of the examples are kind of cool for a beginner. I started with a 150-in-one kit (it was the biggest at the time) way back when I was a teen.
After this... if you want to get into digital electronics, pick up the TTL Cookbook and CMOS Cookbook by Sam's.
If you want to get into audio electronics, pick up the Audio IC OP-Amp Applications (also by Sam's).
If you're a musician, there's a VERY cool one called Electronic Projects for Musicians by Craig Anderton. Use this one with the above audio book to come up with some really cool guitar effect "pedals".
I hope this helps!
You buy the board that way from any real electronics parts supplier (read: probably not Radio Shack).
The boards are fiberglass (or fibreglass if you're in the UK), with copper cladding on one or both sides.
I'd love to get one, if I knew where I could find one.
I've got the feeling all the old flatbed plotters were dumpstered many years ago.