Ways of Recording
MOBOTIX cameras offer a selection of three different recording modes:
- Event clip with variable frame rate and audio,
- Continuous recording with event-controlled frame rate increase including audio,
- Single frame without audio with pre and post-alarm images.
Recording always takes place in the ring buffer process; that means that the camera deletes old images if storage space becomes tight or if the set retention time elapses. Images are stored either in the camera or on a PC/server. There is no need to install any plugins because the MOBOTIX cameras manage the image and audio data themselves.
The recording processes are independent of the selected encoding type (JPEG, MxPEG). However, the highest frame rate and the most effective storage can be achieved with the MOBOTIX-specific MxPEG process.
In parallel to event-controlled recording, history images can be saved cyclically in the ring buffer. Where necessary, your image format may differ from the live image. This means, for example, that an additional megapixel image can be saved every 10 minutes for event-controlled video/audio recording in VGA format.
Event Clip with Audio
A video and audio clip of variable length are recorded in the event clip process. The frame rate can be up to 25 fps. This mode is used as standard in security technology. It only starts recording in response to actual events, such as motion, in the camera image. With an advance run of up to 10 seconds, the run-up to an event can also be recorded. Irrespective of the live frame rate set, the storage frame rate can be adapted in line with requirements and the available storage capacity.
The event clips are divided into 10 second parts (files) and stored on the PC in a folder in the ring buffer. This greatly reduces the number of files compared to a comparable single frame process with pre and post-alarm images. The recording PC is about 10 times more efficient that the old process. Since the camera's internal temporary buffer also reduces the peak network load, altogether 100 cameras can save their images on a single PC on an event-controlled basis.
Continuous Recording with an Event-Controlled Frame Rate
In the case of continuous recording, images are recorded on a continuous basis during the set time of the week, for example from 8 am to 6 pm Monday through Friday. The storage frame rate can be set at between 0.2 and 25 Hz, differing from the live frame rate. In addition, the frame rate can be raised automatically if an event occurs. For example, continuous recording can be selected with an image sequence of five seconds (0.2 Hz) to then be increased to 25 fps if an event is detected.
The video stream is saved in the ring buffer in clear parts of 10 seconds in length. Thanks to this efficient process, around 30 cameras can record a live video stream on a standard PC (Pentium 4, 3.2 GHz) simultaneously at a rate of 25 fps including audio.
If images need to be recorded from a larger number of cameras, other devices or servers can simply be added at any time. The number of cameras per server can be increased in conjunction with a high-spec server PC and a RAID ( Redundant Array of Independent
Disks) disk system. The MOBOTIX process is more efficient than and superior to classical recording with central PC software, in particular in recording at high frame rates.
Single Frame with a Pre- and Post-Alarm
In a single frame process, images of the event are saved in separate JPEG files. In addition, up to 50 pre and post-alarm images can be saved at fixed time intervals in individual files. These images (files) are then combined in one folder in the ring buffer which is named after the number of the event.
The advantages of the single frame process are the low storage capacity for the single image, as well as the possibility of lengthy intervals of up to 10 minutes between pre and post-alarm images. Since the images are saved as separate JPEG files, they can be accessed not only with the integrated playback functions via the browser, they can also be accessed directly by hand or by other programs via the folder. However, the disadvantage of the single frame process is that if there are a large number of pre and post-alarm images and very frequent events from several cameras, the server is subject to a greater load than in the other two processes.
