Homemade Direct-to-Disc on the cheap

[David Suthers]

Thanks for the nice comments. This setup continues to impress me with what it can do. This past week I used it to record events at a track meet, no tape at all (the footage was not important). This time I ran on battery power only. Worked perfectly, although I was limited to about 25 minutes record time because of the weak tablet batteries. (I found a post on here about a NiMH battery pack for about $100 that would REALLY extend my run time though).

I haven't had any troubles with hard drives themselves, but I do not trust the connectors used for firewire. Without secure connectors that screw down or twist-lock, firewire connections will always be a weak link in my book. Also when the camcorder switched off while dvgrab was running (described in an ealier post), the firewire link went down without warning. All of these together make relying on hard drive alone an unwise choice for important video. Also, if you do something stupid like erase the hard drive copy, you can always go back to the tape. I know because I did this... it was late at night, I was tired, and that's all I'm saying.

Really, I think that within the next 5-10 years, a setup like I've built will be obsolete as all camcorders will switch over to either hard drive, optical, or solid state media. But maybe, just maybe, the manufacturers will see products like the FireStore (and to a MUCH lesser extent, mine) and use that as a template for where they need to go.

[Roger Moore]

Hey, Dave, it was fun and educational reading about your reroutes to get to where you wanted to get to, even if I didn't know a thing about linux and tablet pcs. But your hard work, creativity and willingness to get the word out exemplify what this community is all about.

[David Suthers]

Thanks Roger, glad you found the journey interesting... I sure did. :)

I will probably setup the tablet again in the next few weeks to see if I can get it up over 30GB of recording space That and to see if the current updated state of RedHat's Fedora Core 3 will work without a bunch of messing around.

Here are the changes I want to do this time:

1. Decrease the installation partition. Right now I'm wasting a full gigabyte with unused space in the install partition.

2. Put video files in their own partition to keep them from getting mixed in with the Linux OS files.

3. Strip the operating system down to make it as small as possible. No browsers, games, or other "fluff".

4. See if I can install all the software I need without having to compile anything. The only software I think I'll have trouble finding is xvkbd.

5. Keep the firewall turned on, for extra security.

Now that I know exactly what needs to be done, it should be pretty simple. When I do this I'll post another article here that will go step-by-step through the whole process.

David

[David Suthers]

One of the things I wanted to have on the tablet was an on-screen display of the disk space remaining. I'd been kicking this around for a while and finally decided to see if I could write it. Since I'm not very familiar with many of the languages that come with Linux, I decided to see if I could write a script file to do what I wanted. Scripts are similar to MS-DOS batch files, but much more powerful. If there are any Linux gurus out there don't laugh... well, not to my face anyway.

Here's the script:

#!/bin/sh
#

while :
do
#vars:
#mrdf - actual bytes available in the /video partition
#hrdf - human readable free space in the /video partition
mrdf=`df /video | awk 'NR > 2 { print $3 ; }'`
hrdf=`df -h /video | awk 'NR > 2 { print $3 ; }'`

#if more than 30 minutes available (6.72GB+)
#print available space in bold black text on green background
if [ $mrdf -gt 6723869 ]
then
echo -e "\033[0m\033[1m\033[42m "
clear
echo
echo
echo
echo "$hrdf"B
echo -e "Free \033[0m"
fi

#if 10 - 30 minutes available (2.24-6.72GB)
#print available space in bold black text on cyan background
if [ $mrdf -gt 2241290 -a $mrdf -lt 6723869 ]
then
echo -e "\033[0m\033[1m\033[46m "
clear
echo
echo
echo
echo "$hrdf"B
echo -e "Free \033[0m"
fi

#if less than 10 minutes available (2.24GB)
#print available space in bold black text on red background
if [ $mrdf -lt 2241290 ]
then
echo -e "\033[0m\033[1m\033[41m "
clear
echo
echo
echo
echo "$hrdf"B
echo -e "Free \033[0m"
fi

#pause 15 seconds between updates
sleep 15s
done

This progam will display the amount of hard disk space available in an easy to read format, in large type, as well as change the background color depending on the amount of space remaining.

30+ minutes record time available, green background
10-30 minutes record time left, cyan background
under 10 minutes, red background

The program will automatically refresh the display every 15 seconds.

I created this file by typing in the text above into the Text Editor (Applications / Accessories / Text Editor). I called the file "Free-Space" and saved it on my desktop. The next thing was to make the file executable. Right-click the mouse on the file and go to "Properties". Then click on the "Permissions" tab and click the "Execute" boxes for Owner, Group, and Others.

The next step is to add this to the startup programs in "Applications / Preferences / More Preferences / Sessions". Go to the "Startup Programs" tab and press "Add" to add this program. I typed the following into the "Startup Command:" box:

/usr/bin/gnome-terminal --geometry=10x9 --zoom=1.5 --command=Desktop/Free-Space --hide-menubar

In the "Order" box, I set it to 70. Press "OK" to save the new startup program.

Press "Close" to close the Sessions window.

Next I created a Launcher so that I could put this program, setup properly, on the panel for easy access. Here's how: Right-click on the desktop and choose "Create Launcher". A Create Launcher window opens. For the "Name:" entry I put "Disk Status". In the "Command:" entry I typed the gnome-terminal command quoted above. I clicked on the Icon button and chose a toolbox icon. Click on "OK" to save this new launcher.

Drag the newly created "Disk Status" icon up to the panel, next to the XKeyboard and Terminal icons. Now if you accidently close the disk status screen, you can restart it with a single click, or tap in this case.

The problem now is that I still have not found a good way to position the terminal screens in Linux. They open wherever they want. This worked OK when there was only one, but now that there are 2, they open overlapped and in the wrong positions. I'll do some more research and get this working, as there has to be a way.

I have a little more to add to this post, but I've gotta go right now. Stay tuned.

[David Suthers]

In my previous post I was having trouble getting the terminal windows aligned the way I wanted. But like most things I've tried in Linux, the solution was simple, but finding it was much harder. There are more options in the "--geometry" parameter that will do just what I want. So, here are the new settings...

Note: I forgot that I resized the main terminal window in the last post, so I'll include the changes here.

Changing the startup windows:
From "Applications / Preferences / More Preferences / Sessions".
Select the "Startup Programs" tab
Highlight the first item (Order: 50, gnome-terminal) and press "Edit"
Change the Startup Command to this:

/usr/bin/gnome-terminal --geometry=83x14+0+0 --hide-menubar

Press OK to save these changes

Highlight the last item (Order: 70, gnome-terminal) and press "Edit"
Change the Startup Command to this:

/usr/bin/gnome-terminal --geometry=7x9-0+0 --zoom=1.55 --command=Desktop/Free-Space --hide-menubar

Press OK to save these changes

Press "Close" to close the Sessions window.

These same changes will need to be done to the icons on the panel.

Right click on the "Disk Status" icon and select "Properties"
Change Command to this:

/usr/bin/gnome-terminal --geometry=7x9-0+0 --zoom=1.5 5--command=Desktop/Free-Space --hide-menubar

Press "Close" to save the changes

Right click on the "Terminal" icon created a long time ago and select "Properties"
Change the Command to this:

/usr/bin/gnome-terminal --geometry=83x14+0+0 --hide-menubar

Press "Close" to save these changes.

Here is a picture of the screen of the tablet as its configured now:
http://img204.echo.cx/img204/1517/screenshot16hg.png

[Austin Meyers]

i was reading this thread and wondered if it would be possible to hook up an ipod, since they have high capacity, built in easily charged battery, and are set up for firewire already, and you can now run linux on most of the models? or is the harddrive too slow for video capture?

[David Suthers]

The ipod was actually the first device I thought of when trying to build a DIY video capture rig. If I remember correctly, the problem was system throughput and not the hard disk speed. From the specs I found the ipod uses dual 80MHz ARM 7TDMI processors. Not exactly speed demons.

Digital video capture requires 25Mbits per second of throughput (3.1MBytes per second). This is roughly equivalent to copying a 3 minute song every second to the ipod... continuously. If the ipod can do this then, in theory, it could capture video. But it would have to be an older ipod with Firewire to connect to a video camera (newer ipods use USB).

[Austin Meyers]

on the new ones you just have to buy a firewire cord separately, they only include a usb cord, but are most definantly firewire cabable, and i couldn't find any stats on the latest color screen 60gb models

[David Suthers]

I stand corrected on the Firewire adapter. I was reading some newsgroup postings and kept seeing stuff about USB on the new units in reference to video. I should have checked more closely... sorry.

I did a little more searching and re-found an article about video capture on an ipod. In the article the author tried to capture video using his G3 Powerbook as an intermediate and the ipod as a plain external drive. The hard drive spec'ed fast enough but in a real-world test, failed badly. This was the article that made me give up on the idea of using an ipod. This is an older article (May 2002), and if someone has a newer ipod they could probably perform this test again easily. I don't own an ipod or I would have already tried it myself.

Here's the link to the article:

http://www.ilounge.com/index.php/art...video-capture/

[David Suthers]

I haven't posted to this thread in a while and I thought this would be a good time for an update. On the tablet I uninstalled a lot of the extra programs that came with my installation of Linux and got my free space up to 28GB (around 2.25 hours).

To solve my limited battery life problem, I just bought an external battery pack (133WH, 16v/19v) off ebay for $150 plus shipping. The one I bought was from "Battery Inc" and I had no problem with the auction at all. Although this has doubled the weight of my tablet (now at about 4-5 lbs. with battery), I estimate that I have 10-12 hours of run time now. I mounted the battery pack in the back of the tablet's carrying case. Although you can't see the battery, here's an older pic for reference.

http://img232.exs.cx/img232/1746/vidcaprig13aq.jpg

So I now had all the pieces to do a long, tapeless run. Since I normally tape the Friday night high school football game for my nephew anyway, I thought this would be a good test. My sister-in-law was taping on her camcorder so it gave me a backup in case I had "technical difficulties".

I taped 23.5GB of video to the hard drive in 17 clips, with the largest clip being over 6GB. There were no problems during capture at all. I basically let the recorder run except during timeouts, halftime, and after touchdowns. I was able to concentrate more on the subject material and not so much on the minutia of "did I press the record button hard enough?" An unexpected side effect was that I actually had more fun running the camcorder this way than with tape.

I transferred the files back to my editing computer without incident. But I did run into one oddity when I went to edit. Several of the clips showed incorrect run times under Windows Movie Maker. Every other program returned the correct video clip length. Including the MS Windows Media Player... odd.

I use this video to create a highlight reel so I usually just hack the clips and don't spend a lot of time making it pretty. I had been using Windows Movie Maker this program to edit with. So this time I had to break the clips apart using Roxio's DVD Creator. It took a bit longer to edit but I still got good results.

[David Suthers]

I would have never expected this to be read as many times as it has (7700 as of today). And for Chris to make it a sticky is kinda an honor.... Thanks.

Enough mushy stuff and time for an update.

This year so far I used this setup to capture all of the local high school football games (14 games in all). Each game averaged about 24GB and about 20 clips, and captures went very well. I have also captured 2 volleyball games and a couple basketball games. Here is a list of the problems:

1. One time I must have pulled the firewire PC-Card out a little bit when I shut down the camcorder at halftime. When I went to start everything back up, the tablet had locked up and I had to power-off reset. The new tablet battery allows me to keep the tablet running and not worry about shutting it down.

2. On 2 occasions I did have drop outs from the tablet getting behind in the capture. The drop outs were very short... less than 1/2 second, and both times they happened at about 19GB free space. My guess is that since I did not put the video in it's own partition, the OS is having to do some housekeeping. Either that or drive fragmentation is starting to become a problem. Both of these could be solved by putting the video in it's own partition on the hard drive.

That's it. Thats ALL the problems I had. I honestly expected it to be a little flaky here or there but it hasn't. The entire setup has been rock solid.

I have limited hard disk space (about 40GB free) on my home computer so I started even doing some of the NLE and DVD creation directly from the tablet. It worked fine but a little slow as the 2.5" hard drive isn't that fast, and everything is running over my 100Mb network. This limited DVD compression to about 20fps. If the video is stored locally on the desktop then it runs at about 35-40fps.

I've yet to tear down the tablet and rebuild it (and maybe get a bigger hard drive, hehe). I think the dropout problem will force me to do this sometime during the Christmas holiday. If there is interest in me doing so, I will precisely document the rebuild... step-by-step, word for word.

Happy holidays

Dave

[James E Lee]

Hi David,

This is a great post!!!

I am currently following your instructions except that Fedora Core 4 is what's being offered at the main Fedora Web Page. Should I go to one of the mirror sites and get Fedora Core 3?

I plan to install this on a Dell L400 PIII 700MHz 12" Notebook. The computer has a 40GB HDD. Not sure how much to give to the OS. I do want to create a separate "/Video" partition. What do you recommend?

Also, I found a PCMCIA card that offers 1394A Firewire and USB 2.0, it's a generic brand I found at Computer Geeks for $16.99.

Anyway, I plan to get started on this project ASAP. Although I don't have the PCMCIA card yet, will installing it later be a problem?

And do you see anything wrong with what I am doing?

Thanks again for this great post,
James

[David Suthers]

I would go ahead and use Fedora Core 4. That way you will get more up to date versions of the utilities you need.

As far as partitioning, my setup uses about 12GB total for both the OS and the install files. Since you're using a laptop, you can install the OS directly from the CD, saving 4GB right there. To be on the safe side, I'd make the /Video partition about 30GB.

On the Firewire/USB combo card, make sure that it is OHCI compliant. This is important. If it isn't then you'll have a much harder time getting Linux to recognize it. Setup will probably go a little easier if the card is discovered during the install process, so I'd wait until you have the card in the laptop.

Other possible issues:

Since you're using a laptop, you won't be doing the onscreen keyboard or touchscreen stuff, which is good. Getting the touchscreen to work was by far the hardest part of the project. Everything else was pretty much plug & play.

I only have 192MB RAM in my tablet (maxed out). I would make sure that you have 256MB+ in the laptop to make everything run as smooth as possible. If it will take 512MB, then that would be the "sweet spot" IMO.

The hard drive could be an issue if it is an older 4200RPM, 2MB cache drive (which it probably is). Mine is 4200RPM but has 8MB cache and I think this is about as low as you can go. If the computer has more RAM then it may cache the writes to help make up for a slower drive. Also having the video in it's own partition should help performance as well. If you already have the drive and laptop, then I'd give it a shot before replacing anything though.

If you want to play around a bit before locking everything down then you may want to do a larger install. This will put a lot of "bells & whistles" on the computer. You may want to try some of these apps out as a lot of them are pretty good. The 10GB OS partition I recommended above is for a pretty stripped down install, leaving maybe 2GB free space.

Sounds like you have a good plan. Just don't let the differences between Windows and Linux bother you. They really aren't that different, just MS hides everything from the user, while Linux shows you all the nuts & bolts. And remember you can always ask for help.

[Vishad Dewan]

I have an Firestore FS-4 and I really like it. I'm just wondering if your project captures as well as the Firestore does. I'm more than willing to follow your instructions and add a 100gb hard drive to say goodbye to all my mini dv tapes, but I'd like to know if it will deliver good results. Do you have any problems with your rig?

[David Suthers]

Yes it works. It works extremely well. I haven't run tape now in months. I know that this will probably bite me in the butt eventually but the video I capture generally isn't "once in a lifetime" events.

I recently re-setup my tablet with Fedora Core 4 and ran into the following problems:

The touchscreen driver still isn't fixed in FC4. The driver (fpit.o) is better but still isn't quite right (it registers position ok but often double registers taps). Fortunately I was able to copy my compiled driver from the old setup and re-use it.

There is also a problem with the video driver in FC4 on the installation CD that causes the screen to go blank. I had to force a text-based install and boot screen. After downloading the updates the problem was fixed.

Now for the good parts:

The new version of kino no longer runs in lowered-resolution mode. This allows me to review my video at full resolution, although at about 1/2 - 3/4 speed.

The newest version of dvgrab seems to do a better job of handling disconnects / reconnects on the firewire bus. I haven't scientifically tested this yet but it just acts more like USB now.

I no longer had to modify the rc.init script as Fedora now has a place early in the boot process that can be used for custom hardware drivers. This was perfect for relocating the rc.serial script, So now I don't have to change rc.init whenever RedHat updates this file (happened to me twice under FC3).

I upgraded the hard drive to a Toshiba MK6026GAXB (60 GB, 5400 rpm, 16 mb cache) and the drive definitely keeps up better. I also put the /video files on their own partition. Between both of these changes I doubt I'll drop any more frames... ever.

These were pretty minor problems for a geek like myself, but would have been bigger problems for anyone with less linux experience. I've been wanting to do a complete step-by-step for this but just haven't had the time with all of the video I've been shooting (8 basketball games in the past week alone).

If you want to tackle this, I'll be glad to help as much as I can. The end result is definitely worth it.

David