Homemade Direct-to-Disc on the cheap

George Bean · April 7th, 2005, 11:46 AM

David, great information and detailed instructions. It might be more of a project that I can proceed with at the moment.

I am interested in learning Linux. Can you provide any information on the different releases available?

The recent edition of cpu magazine details the os and recommends xandros desktop for users with a windows background. Any info you can provide is appreciated.

Thanks

David Suthers · April 7th, 2005, 08:28 PM

I've mostly been working with RedHat, just because that's what I was first exposed to. I started with RedHat 6.0 and I'm currently using the Fedora Core 3 version. I work in the Windows world most of the time as well, but this project wouldn't work under Windows on the hardware I have.

You may want to try Linspire as it supposedly has a lot of Windows style utilities, and is designed for Windows users. If you do not want to spend any time actually setting up a computer to run Linux, look at Knoppix. Knoppix is a boot CD that does not actually install anything. You can't do any work in Knoppix, but it will let you see how Linux looks & feels.

But my best advice would be to find an old desktop computer and install a "real" Linux like RedHat, Debian, Suse, Mandrake, or any of a dozen different flavors. Even if you screw up the installation, it's a spare computer, so who cares.

David Suthers · April 10th, 2005, 08:51 PM

Update: I originally posted that I could not get the kino video editing program to work on my Fujitsu tablet. It turns out that there is a setting to allow kino to run on video cards with less memory, and this was the problem. The setting is in kino under the following menu:

Code:

Edit
  Preferences
    Display tab
      Display Method: Reduced XVideo

On the Audio tab, uncheck the "Enable Audio Output" checkbox as the audio is very choppy, probably due to the slower CPU. This will help performance slightly.

After changing these settings, kino ran fine. I even opened a 20 minute video clip (4.3GB) and edited it with no problems.

As an experiment, I wanted to see if I could capture video and edit at the same time on this computer. After about 2 minutes the capture would overrun the buffer and start dropping frames. Dvgrab did note that frames had been dropped, and also stopped dropping frames when I stopped editing. The hard drive was churning pretty hard when I was trying to edit so it wasn't a surprise that I had problems. FYI: The hard drive I used is a Toshiba 40GB 4200RPM, 8MB cache drive (MK4025GAS).

David Suthers · April 17th, 2005, 07:24 AM

One of the things on my wish list was to be able to completely eliminate the need for a keyboard. This means that I had to get the touchscreen working from the graphical login (/etc/inittab, runlevel 5). I played and played with this and finally figured out that there was a minor bug in the way Fedora Core 3 Linux starts the serial ports (the touchscreen is nothing more than a fancy serial port). Essentially, Linux had started using the touchscreen before I could properly configure it. The solution was to move the configuring of the serial port to a point BEFORE Linux started using it.

WARNING: This change is one that could really screw up your computer if you do it wrong. The file that I changed is /etc/rc.d/rc.sysinit... the main startup script in Linux.

Step 1: Remove old startup script for the serial port.

I had originally setup the serial ports for the touchscreen in the /etc/rc.d/rc.local file. This script is run after everything else, so it is too late to do any good. Edit this file and put a # character in front of the two "setserial" commands. The # sign denotes a comment in a Linux shell script, similar to a REM statement in an MS-DOS batch file.

Step 2: Create new startup script for the serial port.

The proper way to configure a serial port in FC3 Linux is to create the file /etc/rc.serial (other flavors of Linux do this differently). I did not know this when I first posted this "How-to". The easiest way to create this file is to open the /etc/rc.d/rc.local file in a text editor and save to the /etc folder renamed as "rc.serial". Then edit the file until it looks like this:

Code:

#!/bin/sh
#

#Setup serial ports for touchscreen
setserial /dev/ttyS3 autoconfig
setserial /dev/ttyS3 uart 16450 irq 5 port 0xfd68

Step 3: Move the serial port initialization in the main system startup script.

While I've warned you that you can screw up your computer doing this, it really isn't a diffucult change. If you follow these directions and they don't match up or make sense, then don't save any changes to the file and you'll be fine.

Ok, here we go...

Open the file /etc/rc.d/rc.sysinit in a text editor.

Search for the word "serial", it will find this in a comment line that says "# Initialize the serial ports." (somewhere near line 840)

Copy this line and the next 3 lines.

Go ahead and put a # sign at the beginning of these 3 lines. This will keep them from running, and also mark where they originally were.

Search for the word "graphical", it will find this in a comment line that says "# Start the graphical boot, if necessary; /usr may not be mounted yet, so we" (somewhere near line 230)
NOTE: If you find this near line 700, you have the wrong section.

Just above this comment line, paste the 4 lines that you copied earlier.

Above the pasted serial port initialization lines, I added some more comments (don't forget the #'s) stating what change I had made, and put my name there so I could find it easier. This is entirely optional.

If everything looks Ok, save the changes.

Go ahead and restart the computer, if you did everything correctly, the touchscreen will still work when you start XWindows.

Step 4: Switch to a graphical bootup

Open the file /etc/inittab in a text editor, change the line that says:

id:3:initdefault

to this

id:5:initdefault

and save the file. Restart the computer and you should boot straight into XWindows with a working touchscreen.

By now you're probably thinking "Great, I went through all these steps just to change my login from text to a pretty GUI.... big woop. I still gotta type it in." Well, there is another trick up Dave's sleeve...

Step 6: Automatic login

Yes boys & girls, you can bypass the login screen all together. Here's how:

From within XWindows, go to the "System Settings" menu and select "Login Screen". At the bottom of the "General" tab is a section called "Timed Login". I selected "dave" as my Timed login username, and set the Seconds before login to 15. This way I can still login as a different user if I need to, otherwise 15 seconds later... poof... auto login. Now you are completely free from the need for a keyboard. I carry mine in my kit bag, just in case, but I don't use it.

This is the current state of my setup today and I'm very happy with how it performs. I recorded my daughter's basketball games yesterday as a test of the full system, in the field. It worked extremely well. I had only 1 problem, and that wasn't the tablet's fault. The camcorder went to power off standby mode during halftime and I had to unplug/replug the firewire cable and restart dvgrab. I still captured the scene on tape, but if I hadn't been using tape the camcorder wouldn't have shut off in the first place.

Roger Moore · April 17th, 2005, 02:55 PM

David, I'm thinking of recording to hard drive as well (laptop+dvrack) but my main concern is how reliable the hard drive is when you are walking with it. Can one carry a hard drive around while recording without getting write errors or are you strictly anchored to one spot? I know the operating shock tolerance of laptop hd's are around 160-200 G, akin to dropping the hd to a hard surface from 4 inches, so theoretically, if you walk around softly the data stream should be unaffected.

However in the real world...I have digital wallet type device (CF card -> hard drive) for still photography. I don't know the shock tolerance of the 40 gb fujitsu inside but if I took a couple of steps while it was transferring files the unit would consistently get a write failure. The only way to use it is to set it down, tap your toes and wait for it to finish before moving anywhere.

The FS has a 10 second shock buffer to protect the data stream...without it, I'm not sure how safe I'd be shooting/recording on the go. I wonder if there is a way to emulate this 10 second buffer...

David Suthers · April 18th, 2005, 04:43 AM

If you're having that type of problem with a Cf drive, it sounds more like a faulty electrical/data connection than an actual hard drive problem. Every hard drive I've ever used was either good or bad, not just good if stationary. On laptops I've seen similar behavior and it's always been a loose cable.

With the setup I have, the disk writes are only occuring every 3-4 seconds, not continously. This is a function of both the internal cache on the hard drive (mine is 8MB) and the amout of cacheing the operating system does.

As far as being able to move and use a setup like mine.... I'd think it would work OK as physically it is no different than carrying a laptop and recording. Several people here have said they've done that without hard drive issues. I don't know if I'd film a demolition derby from inside the car with this setup though. Really my biggest concern trying to move & shoot would be the firewire cable coming loose.

Roger Moore · April 18th, 2005, 08:08 PM

Quote:

Originally Posted by David Suthers

Really my biggest concern trying to move & shoot would be the firewire cable coming loose.

I'll be connecting laptop to camcorder later this week...and I'm sure there'll be a lot of kinks to work out. I'll let you know how it goes.

Régine Weinberg · April 19th, 2005, 10:19 AM

Dear David, you can install Knoppix and blow up to a full Debian system, all on the knoppix page, I use it to write this posting

BUT for editing and Sound there is dynabolic it can be installed too and has all for sound and video that might exist in the linux world on board no compiling

hvae fun

David Suthers · April 19th, 2005, 03:09 PM

I was suggesting Knoppix for George as a way to experiment with Linux without any fears or worries. If I were actually installing a version, I wouldn't start with Knoppix. I'd start with a RedHat, Debian, or another distro.

I'm not some big Linux guru, so please don't think that I am. I'm just a fan of the OS and what it can do. Heck, I just figured out what "yum" is this week. :)

Régine Weinberg · April 19th, 2005, 11:28 PM

Fine I do know over the pond is redhat country...
Only to mention Knoppix, there is a version on DVD is Debian based so called Debian unstable and has all tools.I do use it as it has even the Redhat ISDN config as ISDN, Europe..old Europe is la merde with Debian... it can be updated easily and you have the latest Debia Distro rocksolid not so sexy as gentoo but ...there are so many distros out know to be lost...

Roger Moore · April 20th, 2005, 09:52 PM

Quote:

Originally Posted by David Suthers

Really my biggest concern trying to move & shoot would be the firewire cable coming loose.

You're right about that.

My laptop's fw port (4 pin) kept giving me trouble. If the cable moved an inch my connection would die. Probably a few more tugs and the whole port might detach from the motherboard.

Anyways, even though my dell warranty is good for another year I went out and got a bytecc PCMCIA fw adapter. Now I have 2 fw ports (of the 6 pin variety) and the connection never fails no matter how hard wag the cable - also accidental unplugging is not as easy with the 6 pin, being a wider and deeper plug than the 4 pin.

David Suthers · April 21st, 2005, 04:21 AM

Quote:

Originally Posted by Roger Moore

My laptop's fw port (4 pin) kept giving me trouble. If the cable moved an inch my connection would die. Probably a few more tugs and the whole port might detach from the motherboard.

Glad you were able to work through the problem with your Dell's firewire port. So, how well did the setup work? Any dropped frames?

One thing I've started doing is transferring all of my video from tape to the Linux tablet first. I've been having some trouble with my WinXP desktop box doing these transfers. I've noticed momentary jitter on several transfers caused by a bad capture. And during capture I get no indication of any problems. This could be the crappy software I'm using (Roxio DVD Builder & Windows Movie Maker). But I've tried a couple other consumer-grade packages and they don't tell you either. :( Since I started using the tablet, I get no transfer errors. With dvgrab, if even 1 frame gets dropped I'll know about it and that's one less thing to worry about.

David Suthers · April 24th, 2005, 06:44 AM

After my second outing with the tablet, I made a few changes to the setup... again.

Automatically Start Terminal & XKeyboard

When I first started my little project, I wanted to be able to turn on the tablet, and after booting up, be ready to go. I think I have it about as close as I can get right now. I've got the Terminal window automatically opening up in the right place on the screen, and the XKeyboard starting directly below that. But I still have to resize the XKeyboard window to make the keys bigger. Here are the changes I made:

From the Desktop:
Applications / Preferences / More Preferences / Sessions
This opens the "Sessions" screen.

Click on the "Startup Programs" tab.
Click "Add" to add a new startup program.
Type in the following for the "Startup Command"

Code:

/usr/bin/gnome-terminal --geometry=96x12

In the "Order" box, enter "50"
Press "OK"

Click "Add" to add a new startup program.
Type in the following for the "Startup Command"

Code:

/usr/X11R6/bin/xvkbd -geometry -200-95

In the "Order" box, enter "60"
Press "OK"

Press "Close" to close the Sessions preferences screen.

I also changed the Launchers (shortcuts) for both the Terminal & XKeyboard programs as well. To do this, right click on the Terminal Laucher and select "Properties". Add "--geometry=96x12" to the end of the Command entry. Be sure to leave a space after "gnome-terminal". Click "Close" to save your changes.

To change XKeyboard, right click on the XKeyboard Laucher and select "Properties". Add "-geometry -200-95" to the end of the Command entry. Be sure to leave a space after "xvkbd". Click "Close" to save your changes.

More XKeyboard Shortcuts

As I use the tablet more, I find myself wanting to do the same things over and over. Things like check the amount of free space on the hard drive, displaying the directory of captured video files, and clearing the terminal screen. I decided to put these commands as function key shortcuts on xvkbd (XKeyboard).

After starting xvkbd, click on the "xvkbd" icon in the lower left corner and hold the mouse button down. While still holding the mouse button, scroll down to "Edit Function Keys..." and release the mouse button. Select the function key you want to assign the shortcut to by using the same "click & hold + scroll" technique. For the assigned string, type the following line:

To display directory of captured video files:

Code:

vdir /video\r

To display the amount of disc space used/available:

Code:

df /video\r

To clear the Terminal screen:

Code:

clear\r

I put these on the F5, F6, and F7 function keys to group them together, but you can put them wherever you like.

Problems in Paradise

My daughter had more basketball games this weekend, so I decided more field testing was in order. This time I did have a problem with the video capture. During half-time in the first game, I switched the camcorder off before I stopped dvgrab. I had already stopped capturing, but I had not exited the program (I pressed "ESC" instead of "Q"). This locked up dvgrab where I could not exit the program. When I pressed "Q" to quit dvgrab, a "Q" was displayed on the screen. I had to close the Terminal window and re-open it.

When I restarted dvgrab, it did not work. After a little "frantic research" I figured out that the locked up dvgrab was still running. I had to do a "killall dvgrab" to get it to stop, then everything would work again. Since this is not something I wanted to go through again, I decided to assign this command to a function key on XKeyboard, and also include it in the startup for dvgrab (F12). My new F12 shortcut on XKeyboard now reads like this:

Code:

cd /video\rkillall dvgrab\rdvgrab --interactive --noavc --timestamp --size 15000\r

Final Thoughts

Now that I've used this setup in the field a few times, I'll share my feelings on the setup, both good and bad.

The Good:

Longer record times: I have about 2 hours recording capacity now and I still want more. Guess I should have bought the 60GB drive.

Immediate playback: If I need to see an "instant replay" of something, I've got it right there. Without having to "rewind & find".

Reduced wear & tear on camcorder: This pretty much speaks for itself. I can eliminate about half the wear on the tape heads by not having to playback the tapes for capture. All of the head wear if I went totally tapeless (see below)

The Bad:

Setup & tear down: It takes me about 10 minutes to setup this rig for recording. Not too bad for single position filming, but doesn't work for "run & gun" filming. I haven't tried to to wear the tablet yet.

Still need tape: After yesterday's problems, I became a firm beleiver in making a tape copy for backup. I would have lost several minutes of the ballgame without my tape copy.

Power requirements: The tablet I have does not have the best battery in the world. If I relied on the battery without AC backup, I'd only get about 45 minutes of record time... not nearly enough. I'll either need to find a battery pack for this, or I'm stuck with drop cords.

David Suthers · April 27th, 2005, 03:36 AM

I was so close to having the setup exactly like I wanted it after my last post that it bothered me... I had to get XKeyboard (xvkdb) to startup in the size I wanted. After deciphering the documentation, I did figure it out. Here's how to get XKeyboard resized and positioned exactly where you want it.

You'll need to do this change logged in as the root (administrator) account.

From a text editor, open the file "/usr/lib/X11/app-defaults/XVkbd"

Add the following 2 lines to the bottom of the file:

Code:

xvkbd.windowGeometry: 758x250
xvkdb.geometry: -335-75

xvkbd.windowGeometry sets the default window size
xvkdb.geometry sets the default window position

Save the file and that takes care of the first part.

Log out and log back in as your regular user as the rest of the changes needed are user specific.

Since I was already telling XKeyboard a starting position in the startup application and in the launcher icons, I needed to edit them as well.

To change the startup XKeyboard program:
From the Desktop:
Applications / Preferences / More Preferences / Sessions
This opens the "Sessions" screen.
Click on the "Startup Programs" tab.
Click on the program line for xvkdb
Click "Edit" to change this startup program.
Change the "Startup Command" to the following:

Code:

/usr/X11R6/bin/xvkbd -no-keypad

Press "OK"
Press "Close" to close the Sessions preferences screen.

To change the Launcher (shortcut) for XKeyboard:
Right click on the XKeyboard Laucher and select "Properties". Change the command entry to read

Code:

/usr/X11R6/bin/xvkdb -no-keypad

Be sure to leave a space after "xvkbd". Click "Close" to save your changes.

To test the new changes, restart the tablet. Now when the tablet comes up, it is ready to roll... 4 taps and you're recording (Focus button on XKeyboard, Terminal Window, F12 on XKeyboard to start dvgrab, C on XKeyboard to start capturing).

Apparently, I'm gonna keep fixing this till it's broken :)

Dominic Jones · May 6th, 2005, 09:49 AM

Quote:

Originally Posted by David Suthers

Still need tape: After yesterday's problems, I became a firm beleiver in making a tape copy for backup. I would have lost several minutes of the ballgame without my tape copy.

I think that is an *excellent* discipline. Hard drives can and do go down (you're a computer-savvy guy, I'm sure you know that) and computers *will* crash!

On the other hand tapes can and do get chewed up, drop frames, stretch, put lots of wear on the heads (as you say, particularly when scrubbing and capturing).

If you've got a drop-frame-free, no-need-to-capture HDD source with a recorded-once-and-never-touched tape backup, you're in a good position all round, I think.

Congratulations, top job mate!...

April 7th, 2005, 11:46 AM	#16
George Bean Major Player Join Date: Apr 2004 Posts: 248	linux David, great information and detailed instructions. It might be more of a project that I can proceed with at the moment. I am interested in learning Linux. Can you provide any information on the different releases available? The recent edition of cpu magazine details the os and recommends xandros desktop for users with a windows background. Any info you can provide is appreciated. Thanks

April 10th, 2005, 08:51 PM	#18
David Suthers Regular Crew Join Date: Mar 2005 Location: Wytheville, VA USA Posts: 64	Update: I originally posted that I could not get the kino video editing program to work on my Fujitsu tablet. It turns out that there is a setting to allow kino to run on video cards with less memory, and this was the problem. The setting is in kino under the following menu: Code: Edit Preferences Display tab Display Method: Reduced XVideo On the Audio tab, uncheck the "Enable Audio Output" checkbox as the audio is very choppy, probably due to the slower CPU. This will help performance slightly. After changing these settings, kino ran fine. I even opened a 20 minute video clip (4.3GB) and edited it with no problems. As an experiment, I wanted to see if I could capture video and edit at the same time on this computer. After about 2 minutes the capture would overrun the buffer and start dropping frames. Dvgrab did note that frames had been dropped, and also stopped dropping frames when I stopped editing. The hard drive was churning pretty hard when I was trying to edit so it wasn't a surprise that I had problems. FYI: The hard drive I used is a Toshiba 40GB 4200RPM, 8MB cache drive (MK4025GAS).

April 17th, 2005, 07:24 AM	#19
David Suthers Regular Crew Join Date: Mar 2005 Location: Wytheville, VA USA Posts: 64	More Tweaks One of the things on my wish list was to be able to completely eliminate the need for a keyboard. This means that I had to get the touchscreen working from the graphical login (/etc/inittab, runlevel 5). I played and played with this and finally figured out that there was a minor bug in the way Fedora Core 3 Linux starts the serial ports (the touchscreen is nothing more than a fancy serial port). Essentially, Linux had started using the touchscreen before I could properly configure it. The solution was to move the configuring of the serial port to a point BEFORE Linux started using it. WARNING: This change is one that could really screw up your computer if you do it wrong. The file that I changed is /etc/rc.d/rc.sysinit... the main startup script in Linux. Step 1: Remove old startup script for the serial port. I had originally setup the serial ports for the touchscreen in the /etc/rc.d/rc.local file. This script is run after everything else, so it is too late to do any good. Edit this file and put a # character in front of the two "setserial" commands. The # sign denotes a comment in a Linux shell script, similar to a REM statement in an MS-DOS batch file. Step 2: Create new startup script for the serial port. The proper way to configure a serial port in FC3 Linux is to create the file /etc/rc.serial (other flavors of Linux do this differently). I did not know this when I first posted this "How-to". The easiest way to create this file is to open the /etc/rc.d/rc.local file in a text editor and save to the /etc folder renamed as "rc.serial". Then edit the file until it looks like this: Code: #!/bin/sh # #Setup serial ports for touchscreen setserial /dev/ttyS3 autoconfig setserial /dev/ttyS3 uart 16450 irq 5 port 0xfd68 Step 3: Move the serial port initialization in the main system startup script. While I've warned you that you can screw up your computer doing this, it really isn't a diffucult change. If you follow these directions and they don't match up or make sense, then don't save any changes to the file and you'll be fine. Ok, here we go... Open the file /etc/rc.d/rc.sysinit in a text editor. Search for the word "serial", it will find this in a comment line that says "# Initialize the serial ports." (somewhere near line 840) Copy this line and the next 3 lines. Go ahead and put a # sign at the beginning of these 3 lines. This will keep them from running, and also mark where they originally were. Search for the word "graphical", it will find this in a comment line that says "# Start the graphical boot, if necessary; /usr may not be mounted yet, so we" (somewhere near line 230) NOTE: If you find this near line 700, you have the wrong section. Just above this comment line, paste the 4 lines that you copied earlier. Above the pasted serial port initialization lines, I added some more comments (don't forget the #'s) stating what change I had made, and put my name there so I could find it easier. This is entirely optional. If everything looks Ok, save the changes. Go ahead and restart the computer, if you did everything correctly, the touchscreen will still work when you start XWindows. Step 4: Switch to a graphical bootup Open the file /etc/inittab in a text editor, change the line that says: id:3:initdefault to this id:5:initdefault and save the file. Restart the computer and you should boot straight into XWindows with a working touchscreen. By now you're probably thinking "Great, I went through all these steps just to change my login from text to a pretty GUI.... big woop. I still gotta type it in." Well, there is another trick up Dave's sleeve... Step 6: Automatic login Yes boys & girls, you can bypass the login screen all together. Here's how: From within XWindows, go to the "System Settings" menu and select "Login Screen". At the bottom of the "General" tab is a section called "Timed Login". I selected "dave" as my Timed login username, and set the Seconds before login to 15. This way I can still login as a different user if I need to, otherwise 15 seconds later... poof... auto login. Now you are completely free from the need for a keyboard. I carry mine in my kit bag, just in case, but I don't use it. This is the current state of my setup today and I'm very happy with how it performs. I recorded my daughter's basketball games yesterday as a test of the full system, in the field. It worked extremely well. I had only 1 problem, and that wasn't the tablet's fault. The camcorder went to power off standby mode during halftime and I had to unplug/replug the firewire cable and restart dvgrab. I still captured the scene on tape, but if I hadn't been using tape the camcorder wouldn't have shut off in the first place.

April 19th, 2005, 10:19 AM	#23
Régine Weinberg Major Player Join Date: Jan 2004 Location: Bordeaux, going to Bangkok, 2011 Posts: 232	Knoppix Dear David, you can install Knoppix and blow up to a full Debian system, all on the knoppix page, I use it to write this posting BUT for editing and Sound there is dynabolic it can be installed too and has all for sound and video that might exist in the linux world on board no compiling hvae fun

April 19th, 2005, 11:28 PM	#25
Régine Weinberg Major Player Join Date: Jan 2004 Location: Bordeaux, going to Bangkok, 2011 Posts: 232	Re linux Fine I do know over the pond is redhat country... Only to mention Knoppix, there is a version on DVD is Debian based so called Debian unstable and has all tools.I do use it as it has even the Redhat ISDN config as ISDN, Europe..old Europe is la merde with Debian... it can be updated easily and you have the latest Debia Distro rocksolid not so sexy as gentoo but ...there are so many distros out know to be lost...

April 7th, 2005, 08:28 PM	#17
David Suthers Regular Crew Join Date: Mar 2005 Location: Wytheville, VA USA Posts: 64	I've mostly been working with RedHat, just because that's what I was first exposed to. I started with RedHat 6.0 and I'm currently using the Fedora Core 3 version. I work in the Windows world most of the time as well, but this project wouldn't work under Windows on the hardware I have. You may want to try Linspire as it supposedly has a lot of Windows style utilities, and is designed for Windows users. If you do not want to spend any time actually setting up a computer to run Linux, look at Knoppix. Knoppix is a boot CD that does not actually install anything. You can't do any work in Knoppix, but it will let you see how Linux looks & feels. But my best advice would be to find an old desktop computer and install a "real" Linux like RedHat, Debian, Suse, Mandrake, or any of a dozen different flavors. Even if you screw up the installation, it's a spare computer, so who cares.

April 17th, 2005, 02:55 PM	#20
Roger Moore Regular Crew Join Date: Jun 2004 Location: toronto Posts: 99	David, I'm thinking of recording to hard drive as well (laptop+dvrack) but my main concern is how reliable the hard drive is when you are walking with it. Can one carry a hard drive around while recording without getting write errors or are you strictly anchored to one spot? I know the operating shock tolerance of laptop hd's are around 160-200 G, akin to dropping the hd to a hard surface from 4 inches, so theoretically, if you walk around softly the data stream should be unaffected. However in the real world...I have digital wallet type device (CF card -> hard drive) for still photography. I don't know the shock tolerance of the 40 gb fujitsu inside but if I took a couple of steps while it was transferring files the unit would consistently get a write failure. The only way to use it is to set it down, tap your toes and wait for it to finish before moving anywhere. The FS has a 10 second shock buffer to protect the data stream...without it, I'm not sure how safe I'd be shooting/recording on the go. I wonder if there is a way to emulate this 10 second buffer...

April 18th, 2005, 04:43 AM	#21
David Suthers Regular Crew Join Date: Mar 2005 Location: Wytheville, VA USA Posts: 64	If you're having that type of problem with a Cf drive, it sounds more like a faulty electrical/data connection than an actual hard drive problem. Every hard drive I've ever used was either good or bad, not just good if stationary. On laptops I've seen similar behavior and it's always been a loose cable. With the setup I have, the disk writes are only occuring every 3-4 seconds, not continously. This is a function of both the internal cache on the hard drive (mine is 8MB) and the amout of cacheing the operating system does. As far as being able to move and use a setup like mine.... I'd think it would work OK as physically it is no different than carrying a laptop and recording. Several people here have said they've done that without hard drive issues. I don't know if I'd film a demolition derby from inside the car with this setup though. Really my biggest concern trying to move & shoot would be the firewire cable coming loose.

April 19th, 2005, 03:09 PM	#24
David Suthers Regular Crew Join Date: Mar 2005 Location: Wytheville, VA USA Posts: 64	I was suggesting Knoppix for George as a way to experiment with Linux without any fears or worries. If I were actually installing a version, I wouldn't start with Knoppix. I'd start with a RedHat, Debian, or another distro. I'm not some big Linux guru, so please don't think that I am. I'm just a fan of the OS and what it can do. Heck, I just figured out what "yum" is this week. :)

April 24th, 2005, 06:44 AM	#28
David Suthers Regular Crew Join Date: Mar 2005 Location: Wytheville, VA USA Posts: 64	Even more tweaks After my second outing with the tablet, I made a few changes to the setup... again. Automatically Start Terminal & XKeyboard When I first started my little project, I wanted to be able to turn on the tablet, and after booting up, be ready to go. I think I have it about as close as I can get right now. I've got the Terminal window automatically opening up in the right place on the screen, and the XKeyboard starting directly below that. But I still have to resize the XKeyboard window to make the keys bigger. Here are the changes I made: From the Desktop: Applications / Preferences / More Preferences / Sessions This opens the "Sessions" screen. Click on the "Startup Programs" tab. Click "Add" to add a new startup program. Type in the following for the "Startup Command" Code: /usr/bin/gnome-terminal --geometry=96x12 In the "Order" box, enter "50" Press "OK" Click "Add" to add a new startup program. Type in the following for the "Startup Command" Code: /usr/X11R6/bin/xvkbd -geometry -200-95 In the "Order" box, enter "60" Press "OK" Press "Close" to close the Sessions preferences screen. I also changed the Launchers (shortcuts) for both the Terminal & XKeyboard programs as well. To do this, right click on the Terminal Laucher and select "Properties". Add "--geometry=96x12" to the end of the Command entry. Be sure to leave a space after "gnome-terminal". Click "Close" to save your changes. To change XKeyboard, right click on the XKeyboard Laucher and select "Properties". Add "-geometry -200-95" to the end of the Command entry. Be sure to leave a space after "xvkbd". Click "Close" to save your changes. More XKeyboard Shortcuts As I use the tablet more, I find myself wanting to do the same things over and over. Things like check the amount of free space on the hard drive, displaying the directory of captured video files, and clearing the terminal screen. I decided to put these commands as function key shortcuts on xvkbd (XKeyboard). After starting xvkbd, click on the "xvkbd" icon in the lower left corner and hold the mouse button down. While still holding the mouse button, scroll down to "Edit Function Keys..." and release the mouse button. Select the function key you want to assign the shortcut to by using the same "click & hold + scroll" technique. For the assigned string, type the following line: To display directory of captured video files: Code: vdir /video\r To display the amount of disc space used/available: Code: df /video\r To clear the Terminal screen: Code: clear\r I put these on the F5, F6, and F7 function keys to group them together, but you can put them wherever you like. Problems in Paradise My daughter had more basketball games this weekend, so I decided more field testing was in order. This time I did have a problem with the video capture. During half-time in the first game, I switched the camcorder off before I stopped dvgrab. I had already stopped capturing, but I had not exited the program (I pressed "ESC" instead of "Q"). This locked up dvgrab where I could not exit the program. When I pressed "Q" to quit dvgrab, a "Q" was displayed on the screen. I had to close the Terminal window and re-open it. When I restarted dvgrab, it did not work. After a little "frantic research" I figured out that the locked up dvgrab was still running. I had to do a "killall dvgrab" to get it to stop, then everything would work again. Since this is not something I wanted to go through again, I decided to assign this command to a function key on XKeyboard, and also include it in the startup for dvgrab (F12). My new F12 shortcut on XKeyboard now reads like this: Code: cd /video\rkillall dvgrab\rdvgrab --interactive --noavc --timestamp --size 15000\r Final Thoughts Now that I've used this setup in the field a few times, I'll share my feelings on the setup, both good and bad. The Good: Longer record times: I have about 2 hours recording capacity now and I still want more. Guess I should have bought the 60GB drive. Immediate playback: If I need to see an "instant replay" of something, I've got it right there. Without having to "rewind & find". Reduced wear & tear on camcorder: This pretty much speaks for itself. I can eliminate about half the wear on the tape heads by not having to playback the tapes for capture. All of the head wear if I went totally tapeless (see below) The Bad: Setup & tear down: It takes me about 10 minutes to setup this rig for recording. Not too bad for single position filming, but doesn't work for "run & gun" filming. I haven't tried to to wear the tablet yet. Still need tape: After yesterday's problems, I became a firm beleiver in making a tape copy for backup. I would have lost several minutes of the ballgame without my tape copy. Power requirements: The tablet I have does not have the best battery in the world. If I relied on the battery without AC backup, I'd only get about 45 minutes of record time... not nearly enough. I'll either need to find a battery pack for this, or I'm stuck with drop cords.

April 27th, 2005, 03:36 AM	#29
David Suthers Regular Crew Join Date: Mar 2005 Location: Wytheville, VA USA Posts: 64	Resizing XKeyboard I was so close to having the setup exactly like I wanted it after my last post that it bothered me... I had to get XKeyboard (xvkdb) to startup in the size I wanted. After deciphering the documentation, I did figure it out. Here's how to get XKeyboard resized and positioned exactly where you want it. You'll need to do this change logged in as the root (administrator) account. From a text editor, open the file "/usr/lib/X11/app-defaults/XVkbd" Add the following 2 lines to the bottom of the file: Code: xvkbd.windowGeometry: 758x250 xvkdb.geometry: -335-75 xvkbd.windowGeometry sets the default window size xvkdb.geometry sets the default window position Save the file and that takes care of the first part. Log out and log back in as your regular user as the rest of the changes needed are user specific. Since I was already telling XKeyboard a starting position in the startup application and in the launcher icons, I needed to edit them as well. To change the startup XKeyboard program: From the Desktop: Applications / Preferences / More Preferences / Sessions This opens the "Sessions" screen. Click on the "Startup Programs" tab. Click on the program line for xvkdb Click "Edit" to change this startup program. Change the "Startup Command" to the following: Code: /usr/X11R6/bin/xvkbd -no-keypad Press "OK" Press "Close" to close the Sessions preferences screen. To change the Launcher (shortcut) for XKeyboard: Right click on the XKeyboard Laucher and select "Properties". Change the command entry to read Code: /usr/X11R6/bin/xvkdb -no-keypad Be sure to leave a space after "xvkbd". Click "Close" to save your changes. To test the new changes, restart the tablet. Now when the tablet comes up, it is ready to roll... 4 taps and you're recording (Focus button on XKeyboard, Terminal Window, F12 on XKeyboard to start dvgrab, C on XKeyboard to start capturing). Apparently, I'm gonna keep fixing this till it's broken :)