Controlling Lan-C/Control-L-capable VCR With Linux? 7
An unnamed assailant writes: "I want to do a real nerdy project: My VCR has a plug in the back for a LAN-C/Control-L cable which connects to a serial port on a computer as well as a LAN-C connection on a camcorder. The VCR also came with some simple software to control a VCR and a camera through the cable. This was obviously before nonlinear editing was as common as it is now.
Anyway, I want to see if there's any way to figure out what the codes are that the protocol uses so I can talk to the VCR using perl. Any suggestions?" Now this would be a great project, even (or especially?) without the whiz-bang eyecandy of B2K. There are a lot of middle- and high-schools with LAN-C equipped VCRs (most of which probably never get used that way), and it would be nice to be able to control them this way.
Re:controlling a VCR over a network (Score:1)
A friend of mine used a setup like this about 12 years ago to create videos with a Pixar image computer and a Sun Workstation. The VTR was connected to the Sun's serial port and the video input was from the Pixar. That's how he did his computer animation. Lots of fun stuff.
Basic Research (Score:2)
Okay, background, SMTPE, described before, tosses timecode onto the tape (in video blanking interval?). Critical to professional editing.
There are consumer versions of time code. Not as locked down to the frame, but for most purposes, enough.
Professional editing:
2 or more VCRs playing to one recording VCR. (actually in modern times, VCRs are replaced by these computer things - loaded from 1" digital tape for holding the volumes of data that no computer can).
These VCR's (or VTR - the C just came in after reel tapes disappeared) all talk to each other over something that looks serial like. Modern ones may have RS-422 or 232.
Let's now visit consumer land:
Control-S (sony) is simply a wire send of their IR protocol.
This is actually really useful. Same signals as IR means that if you can demodulate the IR. A device called the (slink-e [nirvis.com] does this, albeit the software is on Windows only last I checked. (cool toy)).
LAN-C/Control-L. Described HERE [www.this.is], and I quote:
STFG (Score:2)
Something I found at www.dunfield.com [dunfield.com]
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one word: (Score:1)
Perhaps a RedRat2 would do? (Score:1)
If you don't need any feedback you can IR control most devices with a serial port based learning remote control called a RedRat2. I got one a couple of months ago and have been writing a bunch of software for it:
http://www.slip.net/~gmd/RedRat/index.html [slip.net]
I can control my DVD/CD/VCR/TV/PVR(ReplayTV) and the Gatos TV viewing program on Linux. I'm about to add a MP3 remote panel so I can control the mp3 player on one of my other computers. I suppose I could use the network to do that, but I already have an IRman setup to handle the IR inputs :)
There is a site in Germany that has some LANC based stuff, don't recall the link at the moment. Try search on Yahoo for LANC ...
These links might also be useful to you:
http://members.home.net/ncherry/http://Commander-X.com/hardware.htm
splitter and listener? (Score:2)
I'm not familiar with this thing at all, but if the information is carried over a serial cable, could you make or buy some sort of Y-splitter, with one end feeding into a listening serial port so you can match up actions with output? Same theory as figuring out what a proprietary networking protocol is doing by putting a packet sniffer between the output-generating machine and it's server or client.
Anyhow, just my 0.02 USD. (Oh, and there are perl modules to do serial programming IIRC. So pushing the bits shouldn't be a problem, just see CPAN.) An even easier approach would be finding some docs ;-) but that has less hack appeal.
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"Overrated" is "overfuckingused".
controlling a VCR over a network (Score:1)
I can give some, hopefully interesting, historical info.
About fifteen years ago I had some contact with a pair of industrial VTRs in a workshop where they were used for frame-by-frame animation in the making of television commercials. Those VTRs had something called a SMPTE port. SMPTE is short for "Society of Motion Picture and Television Engineers". SMPTE's web-site is www.smpte.org. The workshop had an adapter that converted the SMPTE port of these VTRs to something that plugged into an IBMPC. I can't remember whether it was converted to serial or parallel. This was a plain old XT, so there was no MIDI port. These VTRs used one-inch tape, and SMPTE timing codes were striped into the vertical blanking interval.
What was I supposed to be working on with these devices? Mastering a videodisc cost $100,000 in those days. I was told by my boss that this guy wanted to demonstrate branching video to investors in order to raise that $100,000. My job was to write a program that could direct the video out of one VTR to the TV monitor, while fast-forwarding the other VTR to the next decision point on the tape.
I assumed that this was some kind of educational application. Wrong. About two weeks into this project I learned it was intended for some kind of soft-core pornography! So I quit. None of the women I knew would have ever talked with me again if they knew I was working in the pornographic film industry.
In the psychology lab where I worked ten years ago we ended up buying a VCR that cost over two grand, that came with software to control it via a serial cable. The microprocessor inside the VCR was able to report back to the controlling computer at 1200 bps.
I never had the time to play with this device. Goldarnit.
My recollection from reading the manual was that the microcomputer inside the VCR had several dozen commands in its command language. But I don't recall that any of them provided access to the VCR's list of programs to tape.