Jump to content

more info on helmet cams please!


Recommended Posts

Buttonman,

I have one of those ATI all in wonder cards in my PC. Its great for all the stuff that you mentioned. It even records digital movies off of a VCR or camcorder really well. The problem with it is you can put the movies on your hard drive or burn it on a CD but you cant take that CD to someone elses house and watch it on their computer unless they have the same card. Thats the big down side to me.

I want something that records good quality and that is uploadable to virtually anyone.

Helmet cams are going for $350 w/ external mic. My buddy has the external mic and it makes a big difference in the sound quality on his camera. So I didnt hesitate to get one with mine. If I recall right they are capable of displaying up to 360 lines of resolution.

As far as the PC Camera...?????

------------------

Darin from Missouri - 1999 WR 400F

Enduro Heaven

[This message has been edited by milkman2544 (edited 03-21-2001).]

Link to comment
Share on other sites

ok.. you asked for it.

Here's a bunch of IEEE1394 reading for y'all to study up on. Pay attention, there'll be a test later ?

Sony white paper: http://www.sel.sony.com/semi/ieee1394.html

A pdf from NEC describing their plan for IEEE1394 http://www.ic.nec.co.jp/nesdis/image/S13782EJ3V0PF00.pdf

nice basic description... http://www.hardwarecentral.com/hardwarecentral/reviews/1738/1/

Philips Semiconductors' data page if you want to design your own 1394 interfaces... http://www.semiconductors.philips.com/1394/

firewire-based products: http://www.videoguys.com/firewire.htm

Link to comment
Share on other sites

This Australian site might be of interest...

Always wanted an affordable helmet mounted color video recording system? ... read on.

This helmet mounted camera is only 36x36x15mm and mounts directly to the liner inside your mouth guard, it is provided with a power supply, camera mounting instructions and remote controlled recording / playback unit that are contained within the supplied backpack for 2 hours of continuous recording*.

All connections are provided for playback to a TV set or to a VCR for tape copying purposes, the unit uses standard VHS tapes of 10,30,60,90,180 or 240 minutes in length and offers incredible quality for such a small system, for aesthetic purposes you can also attach a tinted lens in front of the camera and the unit will remain hidden, the automatic brightness control will even adjust the cameras exposure to compensate.

http://www.eatmydirt.com.au/helcam/index.htm

Link to comment
Share on other sites

How am I supposed to spot the camera with that frilly, lacy, black boulder holder she has on?

Its a trick right? :D?:D:D:D:D:D

No one can spot it with what shes wearing.

------------------

Darin from Missouri - 1999 WR 400F

Enduro Heaven

[This message has been edited by milkman2544 (edited 03-23-2001).]

Link to comment
Share on other sites

Hi Milkman,

There's lots of separate issues. First is quality of the initial picture. Hurtin cameras have <300 lines of resolution and poor S/N ratios. Better cameras are in the 300's of lines and good cameras have >400 lines, like e.g. 450. These are all single CCD, NTSC cameras i.e with the single composite coax you plug onto "video in". Equipment use for real work, like TV, goes substantially beyond the 450 line pro-sumer cameras.

So, stage 2 is record that signal. First there was VHS-C (C for compact) which kind of sucked, down there with the <300 line cameras. Video-8 was about the same, maybe better and then came Hi-8. Hi-8 is pretty good, right on par with SVHS. The latest small format is mini-DV or digital-8. They are codec-compressed, digital stream formats. Those camcorder/VTR's actually have little composite NTSC to DV converter chips built in. DV is the video stream, about 5:1 compressed, that goes through firewire (IEEE1394 is it's technically accepted name). Now here's where an issue similar to copying your buddy's cassette tape comes in. Hopefully he's got a good tape in the first place (Hi-8) that was recorded professionally (good camera) and not with a $20 mic in the garage (<300 line camera with it's probably plastic lense). Given that, you have a good, not bad, source tape as the result of your efforts. If you want to record from this tape, you will get a generation loss regardless, just like making an audio cassette copy. The act of laying it onto the tape an playing it back gives: tape playback is already worse than the original camera signal when you were live. So, hopefully the best source video tape possible can be made, with economics vs quality suggesting Hi-8 and the best helmet cam you can afford.

Now stage 3 is get that signal into the computer. The first economically viable consumer stuff was composite video in capture boards with one humdinger of a computer to handle it. Nowdays all computers are pretty humdinger compared to 5 years ago. There's all kinds of composite NTSC video in boards, but the trick lies in what format they create on the hard drive. (as well as in their quality of analog circuitry). Before CPU's could handle the loading, the favourite was special hardware chip compressors/decompessors. Then you ended up with files you could only play on your machine. This tended to be the only real-time or full frame size/rate options, with tiny picture, slow frame rate stuff being the quicktime and avi files. As CPU's speeded up, the custom chips stuff is fading away and now quicktime and avi methods are supporting lots of different codecs that generally run just on the cpu (i.e. pentium, alpha, G3 or G4, etc). So now your objective is to find a hardware board that will capture the highest quality possible to one of these standard codec formats. In about the past year or two pretty reasonable$ boards will now capture 30 frames/sec full 640x480 full color video. The gotcha is the compression ratio attainable, where 3:1 is heading for broadcast quality, 5:1 is hard to find fault with, 8or10:1 is typically noticebly degraded. A card with higher data thoughput rate is good.

At this stage 3 is where it gets complicated. You can go NTSC Hi-8 analog into a digitiser card which makes your favourite codec file in the best possible quality. Or you can use the hardware codec in the mini-DV or digital-8 camera/VTR and then read an exact no-generation-loss copy through firewire into the harddrive. That removes the generation loss of the played tape then going through the digitiser/compressor. Or, you could go to mpeg-2 hardware which is basicly just another hardware digitiser, but it attains very good quality and smaller data files. However, I think you have to have a very gnarly computer or else the digitiser card to play those files well. mpeg-2 is full size, color and frame rate. mpeg-1 is internet oriented: half resolution and whatever frame rate. The term mp3 is a horrendous screwup done by computer geeks!!!!!! it is really "mpeg 2, audio layer 3", a part of the mpeg2 standard!! It's so screwed up that the poor mpeg consortium now has to skip 3 and go to meg-4 as their next release!! (there, that's vented now) At the moment, there are no real-time VTR-mode full-quality mpeg-2 to digital tape storage handycams on the market (if there is, someone tell me!!)

So, now the data is on the hard drive. Now you need to edit and do cool graphics etc. That's where you can get a program like adobe premiere, final cut pro, DV edit, etc. A real program like Premiere or Final Cut will support lots of codec formats, including DV and give you full editing control. Other programs, like bundled ones, may only handle certain codecs or actually might only work with the card they came with I think the mpeg-2 solutions are typically like that). They may also only allow rudmentary editing functions. When editing, you also have the choice to work in full quality or reduced quality. If you put time into it, you should work in full quality and then convert the finished piece as required. That way you can have the real thing at home and crunch a copy down for the web. The editing programs should have a "save as" menu where you can pick your favourite codec suitable for the web, i.e. reduced colors, resolution and frame rate. This is because video files are huge!!!! Ron in Socal's codec is pretty good in performance vs file size. Till now most previous internet video has looked like grainy stop motion infomercials.

So basicly, Milkman, you should look into codecs supported by quicktime and avi. They're the most universal, and also as other codecs become more accepted they generally get sucked into quicktime or avi (to ensure better compatibility). However, that said, this is a quickly shifting playing field. The only constant is make the best quality source material at the outset. You can always re-process it digitally later on when that zarga-vumph $$$ gizmo becomes real cheap, just like how full rate, size and color digitised NTSC video has now become affordable. e.g full qualty mpeg-2 stuff may be bread and butter fare in a few years, without needing special cards, software etc. That's like DVD quality!!! Just wait, its coming, and then wouldn't it be nice to have good tapes to work from? In a year or two video on CD may be undesirable because of its slowness and size restrictions, and besides, everyone will have a DVD player in their computer anyway. (p.s. DVD is the mpeg-2 codec at full quality).

Confusing? Hope not. Is this the tip of the iceberg for issues about home digital video? oh yeah. So, welcome to the world of home digital video. ?

Link to comment
Share on other sites

WOW! Techman, you definatly picked the right username for the forum.

The information you provided is very much appriciated, albeit just a tad much for me little brain.

I burned....ahem...I mean borrowed a program called MGI Video Wave from someone and it seems to be a very effective program for video capture. I havent looked at enough to know much about it yet but once I get some cam footage Im gonna work with it some more.

I appreciate your detailed response and hopefully someone that knows some more about this stuff can benifit from your quality time at the keyboard. ? Thanks!

------------------

Darin from Missouri - 1999 WR 400F

Enduro Heaven

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

×
×
  • Create New...