On Tue, 22 Oct 2019 21:21:38 -0000 (UTC), Recliner
wrote:

Roland Perry wrote:
In message , at 16:08:54 on Tue, 22 Oct
2019, Recliner remarked:

[CCTV]

Presumably they'll have moved on from HDDs to solid state storage by now?
They're only storing relatively low res compressed JPEGs, so the files will
be small.

My dashcam stores ridiculously uncompressed video.

250MB every 5 minutes.

Downloaded TV shows are typically 200MB for their 42 minutes.

Which is trivial. My A7Riii‡ camera's RAW images are 41.3 MB, and it can
shoot 10*of those per second (ie, more than 200MB in 0.5 sec). The memory
card in the first slot holds 5840 images, and potentially the same again in
the second slot.

Those low res bus camera compressed JPEGs are probably well under 0.5MB
each. If it stores one image per sec from, say, eight cameras, that's maybe
200MB/min at most, probably much less.

‡ Here's some pics I took last week in Ely with that camera:
https://www.flickr.com/photos/recliner/albums/72157711379885958

Excellent pictures from a remarkable building - thanks. But just
three mere glimpses of the very photogenic organ. Pity! I have
played several cathedral organs, but not this one.

Guy Gorton