Following suggestions from a few DCT members last month, Blueskysea were quick to produce a Low Bitrate parking mode beta firmware for testing.
The camera records normal driving in 1080p30fps at 12Mbps. After 3 minutes without movement, the camera switches to 1080p30fps at 4Mbps. Upon detecting movement, it switches back to 12Mbps again.
Movement is detected using only the g-sensor, since there is no GPS to inform the camera that the car is moving. Activation of the sensor saves the current video file in the Event folder. If the car is struck by another when parked, it will also switch from 4Mbps to 12Mbps, since this would be registered by the g-sensor.
The benefit of recording at low bitrate when parked (compared to time-lapse or g-sensor activated recording) is to extend the available recording time on a memory card, whilst still recording at 30fps with audio. In testing, I found no difference in power consumption between recording at 4Mbps and 12Mbps.
Blueskysea have decided to enable the bitrate switch mid-file, rather than stopping the recording and starting a new file. Although there is a momentary video glitch in the current beta FW (comprising just a single frame) the benefit is that the recording is continuous so no information is lost, unlike some other cameras which lose a few seconds of potentially crucial evidence whilst switching modes.
Video Sample 1
4Mbps parking sample
Video Sample 2
Automatic switch from 4Mbps to 12Mbps
This low bitrate beta firmware is still in development and is not yet available for general release. Contact @estore009 for further information.