Hi,
I'm a sysadmin for an electrical engineering dept at a university. We're interested in replacing an ageing analog multiplexor/time lapse VCR with something a bit more modern for storing images for our lab surveillance system. We're looking at getting a Spectra8 and maybe a Spectra4 or other bt8x8 capture card (we have 9 cameras currently, we may expand further), a few hundred Gb of RAIDed IDE drives, a hyperthreading P4, a few gigs of RAM, debian linux, mysql filesystem on the RAID and mixing it all together appropriately and running something like ZoneMinder to record the video.
However, since our labs are in 24 hour use, we don't need the motion detection of ZoneMinder, but we would only need to save about 1-5 fps from the video stream of each camera (theorhetically up to 50fps of capture). I have had a look at the changelogs for ZoneMinder, and I get the impression that this should be possible, but if someone would be able to confirm that, that would be great.
Another feature we would require is some means to limit the storage of frames, based on time. Since it stores all the frames in an SQL database, we should just be able to run an SQL command from cron to delete all frames older than a certain date, yes? And on that subject, it looks like there are predefined methods of making it output MPEGs of a given time range from a given camera, which would be handy for review purposes.
Another thing I'm interested in knowing is if the frames are stored in the database in JPEG format or in raw RGB format? Storing at 640x480, 50fps at about 20Kb/frame (JPEG) would end up at ~1.2Tb per 14 days of footage? If so, we'ld probably go for about 10fps instead of 50fps, only 1 fps from each camera, for only 200GB of data, but allow for say 400GB just in case..
Ok, and one last thing, more about v4L.. if zm is reading from an input, can another v4L app also read from it? In addition to running ZoneMinder, we'ld also like to run something in X11 or on framebuffer to cycle thru the inputs and display the output on a small TFT display or a TV.
Sorry, lots of questions and I haven't even had the chance to actually use it yet. I have a TurboTV card I can try it with at some point, but I've currently lent it to someone for the next month or so. Any feedback or other comments on these questions is welcomed
Thanks