Wednesday, June 28, 2006

Camcorder Fun

An increasingly popular trend, what with all these blogs kicking about over t'internet, is to put your own video footage up on the 'web. Skills and spills adorn video.google.com. So how do you go about capturing your exploits for web sharing?

I'm going to make it easy and exclude certain methods because, frankly, they're either too expensive or too crap. In the former bracket are things like the solid-state recorders you'll find popular with the motoring fraternity, as sold by the likes of DriveData - it's very swizz, yes, but extortionately costly. At the other end of the scale would be attempts to strap mobile phones to your forehead, or else use something like the Tony Hawks Helmet Cam which, while cracking value for money for the kids, doesn't offer brilliant picture quality or, more importantly, frame rate.

So what makes a good bit of video? Well, for it to appear smooth to the eye you want at least 25 fps (frames per second) and you want a quality to the picture that makes it watchable. In computer terms, that means a good balance of resolution versus compression. High resolution and low compression makes for great footage but it's size is often not suited to distribution over the internet - ~20MB a minute if you take raw, DVD-quality MPEG2 footage like you would find on a DVD or digital television.

Anyway, we'll come back to the ins and outs of converting the footage to computerised format. How do we get the video captured in the first place? Well, some people suggest bolting a camcorder onto your helmet but personally I find this a rather daft proposition; the camera is a delicate item liable to get smashed to pieces on your first off, plus you've got lense and tape head jitter plus the problems of making the camera rain-proof.

First off, get yourself a digital (MiniDV) camcorder with Firewire/USB2.0/DV output and AV Input. Canon do great value products; the MV range has varying models from the 730i upwards (or the older MV600i is perfect). Digital is there so you can get the footage off onto a PC easily, and it's also a suggestion because the cameras suffer from little head shake (ie. they shake around but the heads that record the signal onto the tape don't jitter about too much resulting in loss of picture quality). Firewire/USB2.0/DV is there to offer connectivity to your PC. If your PC doesn't have either a USB or Firewire interface, they can be purchased separately as add-in cards relatively cheaply (<£20). Finally, and most essentially, AV Input allows you to connect an external camera lense to your camcorder. Next, then, is to sort out your external lense - head over to RF Concepts and grab yourself one of their waterproof, colour, PAL bullet cams (the 21CW does the job). Then take a look on this page, and grab yourself the microphone kit (£12.50), battery pack (£5) and if you don't have any at home already choose some suitable batteries and chargers. Personally, I think you'll find alternative cheaper sources of AA batteries. Essentially, your remote camera lense needs 12v of power, so you'll need 8 suitable batteries to power it.

You might want to treat yourself to a LANc remote control if your camcorder has a LANc port on it; this means you can tuck the camcorder away in your packpack, plug the remote control into it, and feed this outside of your backpack so you can stop and start recording with ease.

Don't bother with any fancy helmet mounting systems - a trip to your local motor factors for some gaffer tape will sort the lense mounting system out cheaply!

So, running bill so far (worst case; if you had to get everything but assuming you've got a PC!) :-

  • Camcorder (Canon MV700i; £250 from Amazon)
  • 21CW Bullet cam (colour, PAL, waterproof; £103.40)
  • Microphone kit (£15)
  • Battery pack (£6)
  • LanC remote control (£41)
  • 8x NiMH batteries & charger (£32)
  • Gaffer tape (~£2)

So that's £450 and you're sorted! Now granted, that's a lot to spend purely to record your mountain bike exploits but realistically you might have another justification for buying the camcorder... "Darling, I was thinking of getting a camcorder to record the little sweethearts on holiday" etc etc. You could also live without the remote control and possibly even the microphone if you didn't want sound.

All you then need is a PC to download it all onto, chop and change it (there's plenty of free internet software to do this, as well as Microsoft's Movie Editor on Windows XP) and convert it to a web-friendly format. This will most likely involve reducing the resolution to something a little smaller (320x240 pixels minimum) and converting it to a suitable compression format. I would recommend any of the free MPEG4 codec out there - DivX, XViD or the latest H.264 HD codecs. Once you've converted it and reduced the size to something sensible, upload it onto your favourite website and start bragging!

You can see some examples from the first test run of Knobblie's Helmet Cam below; for comparison I've included what codecs were used for each one so you can see the difference. All were edited and re-encoded with Pinnacle Studio 9 rather than anything fancy, so they're good examples of what a non-professional home user can achieve...

Windows Media, Low quality, 180x144 res - 409Kb
Windows Media, Medium Quality, 360x288 res - 6.5MB
MPEG4 (DivX), Half Size (360x288), 85% quality, MP3 audio - 18.3MB
MPEG2 (DVD), Full Size (768x576) - original 100% quality - 21.8MB

For some example footage of my setup (rally car, though, not mountain biking - yet) check out some of the event dates here.

6 Comments:


Farqui said...

I'm glad to hear that you've now got all the kit to capture our MTBing "antics". It's sure to be alot a fun.

Your techno blurb almost makes sense, for a change ;) A nice overview there Brummie man.


Dan Howell said...

For some general PC-video-editing links, check out :-

AVISnyth - video editing
doom9.net - wealth of video manipulation related information
GUI4ffmpeg - a front-end for ffmpeg, a fast, highly configurable and portable video transcoder for converting video files from one format to another


Farqui said...
This comment has been removed by a blog administrator.

Farqui said...

Nice work there fella. They don't look jerky, that'll be down to the frame rate right ?

The different qualities show just how good the compressed version is, albeit smaller. The MPEG4 version just showed me a "randomisation", is that 'cos I don't have the right codec installed ?

I hope you'll be bringing your gear to Woburn this Sunday.


Dan Howell said...

Yes, MPEG4 means you'll need a codec installed which isn't part of Windows "out the box". DivX 5.x should work a-fine. There is a Microsoft MPEG4 codec standard but I don't use it :(

Yep, I'll bring the cam this Sunday...!


Farqui said...

Just found a snazzy introduction to video setups over at Peter Fagerlins website.


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