Homemade Direct-to-Disc on the cheap

[Vishad Dewan]

Yeah, I'd love to do this project. Adding a 100gb hard drive will make my life that much easier. I'm not sure if the video quality will be as good as with the Firestore, but I don't expect too much difference. I'm assuming your rig records only Raw DV. Would there be any way to configure the rig to record, let's say, Quicktime or Canopy AVI?

I'm not good with computer programming. I did some back in high school, but I know I have never touched on Linux. Your steps seem straight forward enough. Do you expect someone as amateur as me to run into any programming problems?

I really do appreciate all you're doing for this project. You really deserve a big applause.

Thank you!!

Vishad

[Dan Euritt]

from what we've seen with the fs-4, raw dv is the only format that will allow for accessible 4-channel audio recording in the dv format... at least on the pc side off the editing fence, anyway.

there have been reams written about the subject in the fs-4 forum, but if you really want a challenge, see my website for a sample clip that you can download... try to pull the 4 channels of audio out of it.

quicktime on the pc will let you hear all 4 audio channels playing at once, but it won't seperate 'em out.

anytime that you record the 1394 signal coming off of the camera, it'll be exactly the same quality as what's on the videotape... there is no transcoding, it's just a simple data copy of what is being written to the videotape.

[Vishad Dewan]

i have a friend with a jvc hd cam he bought late last year. i mentioned that he'd rather not buy a dte until there was a viable way to save his hd format. is there any way your rig could do that?

i also saw the pictures you posted. quite frankly, i think u did an exceptional job. but is the converted tablet only a dte now, or can you still run other programs on it? u can't actually play back ur footage, can you?

[David Suthers]

Since everything is digital, the video quality is the same as a Firestore or good tape. Now if the tape has a dropout, then mine would be better. :)

The dvgrab utility that I use for capturing can format the video as dv1 AVI, dv2 AVI or RAW (.DV) which can be used by Quicktime. I left the default as dv1 AVI and my video editing software (Roxio & MS Movie Maker) liked the files just fine without conversion.

As far as needing to do programming, it really isn't necessary. I've written the only program already to display the space available. What is required is the ability to edit configuration files, but even then, I've listed which files and what changes need to be made. If you can edit a file using Notepad in Windows, you can do this. The one piece of the configuration that requires outside help is the touchscreen driver. And since I have a working version, I'll be glad to email it to anyone who needs it.

Is the JVC cam your friend has a high-def or hard-drive cam? I'll assume "hd" means high-def. The dvgrab program as far as I know, only captures the 25Mb dv video streams. These streams (dv25) are for standard-def signals. There are some working utilities for capturing high-def video in Linux (test-mpeg2 utility that comes with libiec61883) but since I don't have a high-def camera I can't test any of this... anybody wanna donate one to me?

My tablet setup is not limited to just DTE, but is still usable as a regular computer. I installed Open Office on the tablet and left the games on the tablet for my daughter to play. The kino video editor allows me to review the captured footage and edit the video. Unfortunately, kino playback is at about 3/4 speed. And since the video plays back slower than real time I disabled the audio playback as well. You have to remember that this is a 400MHz computer, not exactly "state of the art". But one big advantage of using kino is that I can capture a few seconds of test footage, and then review it to check my video gain levels. Nothing more frustrating than recording an hour of severely overexposed/underexposed video because the LCD on the camcorder solarized.

David

[John Yamamoto]

Hi, i try all settings and still no way to get live capture from no luck
JY

[Kevin Richard]

David, I assume this tablet has a floppy... I have found floppy based boot disk that let you access either network or cdroms to install from... that would be one way to do the install... OR a DSL linux install those are VERY small (50mb) so you don't loose much on install.

Also you should be able to keep your system partition VERY small... though fedora is somewhat bloated (and hey, I use it and like it)... debian can get pretty minimium and still full featured.

I assume you have also toyed with the option of now being able to swap the two drives in the field to extend record time... though not super fast option it's a viable one.

I'm no linux guru either, you look to be probably as proficient if not more so than I am... but like you I like fumbling with this stuff!

[David Suthers]

The tablet does have an optional external floppy. Mine was included in the auction. I originally tried to use a CD to install Linux, but the problem was the tablet came with a BackPack parallel port CD-ROM. The BackPack was such a strange device, it was not surprising that FC3 (and FC4) failed to recognize it.

Also at the time my internet connection wasn't really good enough to attempt a download install. Besides, I didn't know how much messing around I'd have to do to get Linux running. It would have been a big hassle to have to online download an installation several times. For now, I can live with the loss of a couple gigs for the install. I may yet revisit this issue with an external USB CD-ROM or hard drive.

I did consider using debian to make the installation smaller, but I am more familiar with RedHat, so that's what I used. Another option would be to setup a local FTP or SMB server with the images on the server.

Swapping hard drives was not an option that I've look at. I currently have 40GB of video storage, which is over 3 hours... plenty for any filming I need. If I wanted to go this route, I could ghost a couple of extra drives and be able to power-off swap them in about 5 minutes. The big problem would be the hard drive cable, which is a ribbon cable and too fragile for many swaps.

Enjoy the "fumbling"... it's a lot of fun. :)

[Kevin Richard]

Yeah, I was mainly speaking of doing net installs on future upgrades/installs.

I was hoping that the hard drive slid into a slot and wasn't so finiky.... oh well.

Hell for the price you could really just get a 2nd unit whole nother back up system ready to go if something were to go wrong... you've done the hard part... you wouldn't need to re-buy any periphials unless you wanted to run a second cam... and you got the HD sitting around.

[Dan Gonzales]

Wow you should set those things up and sell them on ebay. You would make a killing. The cheapest DTE is $650. Not to mention you can see video on yours and you could always get a faster unit for playing video in real time. I am in awe.

[Albert Schuurman]

Hoi forummembers.
I'm a Dutch mail of 66 years en retired now and have read the whole discussion on this matter. I doe a lot of video shooting and also mounting on the computer.
I seems that David has make a goed device. However, I search a lot time to the internet to find the commando's send viceversa from camera to device, (Mediaplayer, Capture devices, recorder, etc) i.e. play,pause,rew, ff etc.
But find nothing sofar. I found this site well.
Mayby I used the wrong search strings. Can anybody gif me some clou where to look.
I will tray write directly to a HD from a different angle then david has done.
Thanks in advance and sorry for my english writing
Best regards
Ab Schuurman

[David Suthers]

Albert,

I've done quite a bit of homework on this subject, so maybe I can help. What are you looking to do? What camera do you have? How many hours of storage space needed? Battery run times? All of these questions are relevant in determining the best capture device (iPod, PDA, laptop, etc.). The main problems from a computing standpoint are handling the data rate of 25 megabits per second (8.3 megabytes per sec.) and the firewire interface.

David

Update: I'm currently starting version 3 of my tablet setup, this time using Xumbuntu Linux. I'm trying this linux because it is specifically designed for older, slower computers. It is also a very small distro that should also allow me to shrink the size of the installation partition.

[Albert Schuurman]

David

Tanks for your reply.
Yes, your right. Handle a datastream of 25 Mb/s is not easy, but it can be done.
I'm familair with the technicals aspects. There is a lot info on the internet.

What I looking for is de commando code (or string) witch is be send by the camera when I push the Record/Stop button in de camera modus.
I use the Sony DCR-VX9000E (PAL) camera and make the film(s) with Adobe premiere 6.5.
I film small documentaries or films about a sportsclub that exist 110 jaar and ofcourse the holliday movie's.
For the holidays I use a the small Sony DCR-HC23E.

I'm able now to store the shots on a HD.
Picture it, I connect the camera trough the firewire cable on my laptop and start a program VIDAB.
(capture program running onder windows XP) The existing (VIDCAP) program is modifyed to do the job.

The progran look first, at the pointed externe 1,8" HD of 40 Gig connected true USB 2.0, to the lest file on that disk.
The name is SH(number). (SH=SHOT) Then de program wait for the start commando.
I point the camera to the scene I need to storage and press de spacebar.
The program store the data comming trough the firewire cable to the HD untill I press the spacebar again
The file wil be closed and the program wait untill I press the spacebar again.
The file counter opnumber the filename with 1.

This is the reasson that I wil find the commandstring from the start/stop button on the camera.
I d'nt need de spacebar anymore.

After I take all the needed shots (I go home). I take the HD off the laptop and connect it to my computer where I run Adobe on.
I read the files sh(1) to (x) files directly in Adobe and work the film totally on this HD.
Important time to win is that I do not have to capture the shots
After I finisd the movie I make a DVD of whatever.

In normal modus the laptop can function approx 2-2.5 hours.
I do not need the screen so I shut it down and win approx 1 - 1,5 hours extra batt power.
I do not use tapes so the recorder engine remain oke.

I hope I make it clear to you where I'm bussy with.

You can see that I have won a trofee with a 16 minut film , about a pour familie whit big deads(mony),what I have made with my companions from a small videoclub
In November our film wil be projected in a large communityhall and maybe we win again.
http://www.clubs.nl/community/default.asp?clubid=261300
scroll down and on they end I stand behind the trofee.

Greeting Ab

[David Suthers]

I'm not sure that dv video capture will work on current 1.8" drives.

Like most specifications anymore, the listed performance from the manufacturer is the HIGHEST possible transfer rate, under ideal conditions. If you go to www.tomshardware.com you can find real performance testing on hard drives. They tested several 1.8" drives and the performance drops are significant. The Toshiba MK8007GAH, 1.8", 80GB drive has a maximum write speed of 26 megabytes per second, but drops to 11.7 megabytes per second on the slower innermost cylinders. 11.7MB/s is approx. 93.6 megabits per second which is still plenty fast enough for video capture, but this is raw throughput. We have not added file system overhead, nor have we accounted for bad sector re-mapping, a feature of all current drives. The 1.8" drives also come with only 2MB cache, which would be less forgiving of performance "dropouts" than 8 or 16MB cache drives.

Using the data from the performance charts in the article, a 1.8" drive is about 33% slower than the equivalent capacity 2.5" drive. I had minor performance issues on my 40GB, 8MB cache drive in my tablet, and that was a big reason I upgraded to a 60GB 16MB cache drive. I don't know that any amount of tweaking could have overcome a 33% performance difference.

I don't like being the one who says that something can't be done, but I'm not sure the technology is there quite yet.

Article Link:

http://www.tomshardware.com/2006/04/..._is_beautiful/

[Albert Schuurman]

David,

I read the mentioned articles and I agree that those drives are not good enough. Thanks for your effort.

I looked where a made my mistake in my posting.
I have look on a earlyer drawing from the first concept to make it so small as possible.

I use now a Toshiba 60Gb notebook drive 2,5", 5400 rpm. Its fit in a box with 1 usb 2.0 connection to the computer.
A second usb cable is in use for only the power for the drive.

I have taken a lot of video with my installation and de files are all oke. No dropped frames are discovered.
So I'm happy sofar. I see well that different improvements are possible.

I expected, in fact, more comment on my concept.

And can you, or anyone else, help my out with my first question about the used code strings?? for start/stop recording in the camera modus.
Where to look or wich string can give more result.
I found something on IEC 61883 (x) but they tell me a lot about making the connection IEEE 1394 and how to remain it and the the format of the data pakkets en the place of the commandostrings i.e.
but nothing about the commandoset self.
So I looking forward to hear something, If possible.

I wil now look how to strip the laptop and remove the not used parts.
First I make inquiry the possibility to run XP and my VIDAB program on a flascart.

Have all a nice weekend
Bue Ab

[David Suthers]

The dvgrab program that I use under Linux is supposed to be able to read the record commands from the camera. I haven't tried it. I found a thread on the dvgrab forum that you may want to look at:

http://www.kinodv.org/dcforum/dcforu...2&topic_id=748