My hints and tricks

[jdog109socal]

http://youtube.com/watch?v=wmDPLB9FWtg

Jdog

[admin]

As part of our buisness, we make videos for engineering/driver training/sancitioning body purposes in professional and club racing. We have systems in Grand Am, ALMS, SCCA and AMA motorcycles, so we have a need for clear, easy to transfer and durable video systems.

We've been using Chasecam 580 line cameras and mics with excellent success. We record these with a variety of Digital DVRs, and then transfer them to 100GB portable hard drives. Each car gets a drive, and videos can be played directly in Windows Media player by the drivers, engineers or crew chiefs. We will sometimes edit these down with Windows Movie Maker so they can be easily transfered, as a race can be up to 2GB long.

Our biggest challenge has been DVR's. We've tried Mustek, Acros, and AIPTEK DVRs with varying levels of failure (note that I didn't say success...) The ability to hand someone a 2GB SD card or hard drive with video is very important to us, where carrying a video recorder and cuing something up on a TV is not practical.

A great example was at Mid-Ohio last week, Pat Long got hit pretty hard by Bill Auberlen in the Grand Am Cup race. The team manager asked to see video, and it was available immediately on the laptop. Furthermore, copies were able to be made and distributed to those who needed them.

We had another incendent at Daytona where a driver was dealing with an oversteer condition into turn 1, and we were able to very accurately pinpoint that it was in corner entry after turn-in but before the apex.

We use AIM DAVID systems on several of these cars and they work great. We record in VGA for practice/qualifying (about 1GB/hour) and QVGA for races (about 500MB/hr). We've limited by battery life on the AIPTEK recorders being about 2 hours. I'm looking forward to getting a PDR100. It sounds like with that, our reliability issue will finally be a thing of the past.

Orig posted 07/06

[admin]

DivX... DivX is a free video codec you can download from www.divx.com. I use version 5.05 because I'm too lazy to download the update :D

They have programs on that site that will allow you to convert video into the divx format however, I do not and have not used them.

All my video re-encoding is handled by a nice little program known as VirtualDub

http://www.virtualdub.org/

Steps I took to convert your video from MPEG to DivX:

- Open your file in Virtual Dub
- Hit the 'video' menu, go to compression, select DivX and hit configure
- To loose 10 megs the following was set:
**Under the 'Bitrate Control' tab**
=Variable bitrate mode: 1-pass
=Encoding bitrate: 362kbps
**Under the 'General Parameters' tab**
=Psychovisual Enhancements: Unchecked [I honestly don't know what this does, and I can't tell a diffrence with it on or off]
=Max Keyframe Interval: 60 Frames [This is how many 'notches' there are on the video slider durring playback. 1 every 60 frames = 1 every 2 seconds assuming 30 frames per second]
=Performance/Quality: Slowest [Since the videos aren't very long, even a fairly old computer will handle them in an acceptable amount of time. It took me ~30 seconds to re-encode your video, I have a 2GHz CPU]
**Under 'Profiles' tab**
=I always select high definition. It keeps distortion down.
- Hit ok to close that window, and again for the compression selection window.
- Hit the 'audio' menu and change to 'full processing mode'
- Hit the 'audio' menu again and hit 'compression.' I used MPEG Layer-3 [MP3] at a rate of 40kBits/s.
- Hit ok, go to 'file' and 'save as,' give it a filename and hit save. A small window will pop up and show you the re-encoding statistics.


I know that looks like alot of crap to go through, but once you get comfy with the program you'll set things how you like it and will only change one or two things per video. You can also give Dr. DivX a try if you'd like.