C5 Fare Dodgers - question

Post by tim...
Did others see this?
Not that you need to have done to answer my question
The program appeared to show the roving RPIs/Police Offices had real
time access to the CCTV inside a specific bus (that they weren't riding
on).
Do they really have that capability?
Or was this just post editing of the program to pretend that they did?

You've just answered your question.

--
Graeme Wall
This account not read.

MissRiaElaine

2019-10-22 12:58:15 UTC

Post by tim...
Did others see this?
Not that you need to have done to answer my question
The program appeared to show the roving RPIs/Police Offices had real
time access to the CCTV inside a specific bus (that they weren't
riding on).
Do they really have that capability?
Or was this just post editing of the program to pretend that they did?

You've just answered your question.

Real time access to onboard CCTV *is* possible, if the right equipment
is fitted. It's rare, though. The company I used to work in CCTV for had
it fitted to a limited number of buses, and the police had mobile
receiving equipment in a following car/van.

--
Ria in Aberdeen

[Send address is invalid, use sipsoup at gmail dot com to reply direct]

tim...

2019-10-22 14:34:52 UTC

You've just answered your question.

Real time access to onboard CCTV *is* possible, if the right equipment is
fitted.

Fitted where?

on the bus,

in the control room

in the RPI's equipment?

It's rare, though. The company I used to work in CCTV for had it fitted to
a limited number of buses, and the police had mobile receiving equipment
in a following car/van.

It seemed from the rest of the program that onboard CCTV is retrospectively
available via the control room servers.

So, is that, saved "live"? Which would be a bit of an overkill for hundreds
of busses and what, 7 or 8 cameras per bus. Or uploaded at the end of turn
(the bus, not the driver).

tim

MissRiaElaine

2019-10-22 15:07:17 UTC

Post by tim...
Did others see this?
Not that you need to have done to answer my question
The program appeared to show the roving RPIs/Police Offices had real
time access to the CCTV inside a specific bus (that they weren't
riding on).
Do they really have that capability?
Or was this just post editing of the program to pretend that they did?

You've just answered your question.

Real time access to onboard CCTV *is* possible, if the right equipment
is fitted.

Fitted where?
on the bus,
in the control room
in the RPI's equipment?

Post by MissRiaElaine
It's rare, though. The company I used to work in CCTV for had it
fitted to a limited number of buses, and the police had mobile
receiving equipment in a following car/van.

It seemed from the rest of the program that onboard CCTV is
retrospectively available via the control room servers.
So, is that, saved "live"? Which would be a bit of an overkill for
hundreds of busses and what, 7 or 8 cameras per bus. Or uploaded at the
end of turn (the bus, not the driver).

The bus has an onboard HDD recorder which has capacity to hold footage
for around a month or so. The way it usually works (or did with us) is
that under normal circumstances, these are recording all the time that
the bus is active, from the moment the engine is started to a preset
period (a couple of hours or so) after it is switched off.

When the bus returns to garage at the end of the day, any incidents that
have been requested will be downloaded to the server. The whole of the
contents of the buses' HDD's will not be downloaded, this would just be
a waste of time, as for 99% of the time nothing important is happening.
You only need to download what you need to investigate any particular
incident that has been reported. If the bus happens to be in the garage,
then it's usually quite easy (I say usually, as sod's law says the
equipment on the bus will have failed when you really need something and
the police are standing next to you waiting..!) to download what is
needed and put it on a DVD or whatever. If it's out on the road, you
generally have to wait until it's back, hence it isn't possible to get
instant access.

For the purpose of a specific police operation, then they would follow a
bus in another vehicle and link directly to it, in this situation they
would be able to view the cameras live without being on the bus.

It *is* possible to view live camera feed from a moving vehicle back in
the garage, but it needs something like 4G fitted, which quite honestly
the company I worked for didn't feel was financially viable. Personally
I disagreed, but then I wasn't in charge of the budget.

--
Ria in Aberdeen

[Send address is invalid, use sipsoup at gmail dot com to reply direct]

Recliner

2019-10-22 16:08:54 UTC

Post by tim...
Did others see this?
Not that you need to have done to answer my question
The program appeared to show the roving RPIs/Police Offices had real
time access to the CCTV inside a specific bus (that they weren't
riding on).
Do they really have that capability?
Or was this just post editing of the program to pretend that they did?

You've just answered your question.

Real time access to onboard CCTV *is* possible, if the right equipment
is fitted.

Fitted where?
on the bus,
in the control room
in the RPI's equipment?

Post by MissRiaElaine
It's rare, though. The company I used to work in CCTV for had it
fitted to a limited number of buses, and the police had mobile
receiving equipment in a following car/van.

It seemed from the rest of the program that onboard CCTV is
retrospectively available via the control room servers.
So, is that, saved "live"? Which would be a bit of an overkill for
hundreds of busses and what, 7 or 8 cameras per bus. Or uploaded at the
end of turn (the bus, not the driver).

The bus has an onboard HDD recorder which has capacity to hold footage
for around a month or so. The way it usually works (or did with us) is
that under normal circumstances, these are recording all the time that
the bus is active, from the moment the engine is started to a preset
period (a couple of hours or so) after it is switched off.
When the bus returns to garage at the end of the day, any incidents that
have been requested will be downloaded to the server. The whole of the
contents of the buses' HDD's will not be downloaded, this would just be
a waste of time, as for 99% of the time nothing important is happening.
You only need to download what you need to investigate any particular
incident that has been reported. If the bus happens to be in the garage,
then it's usually quite easy (I say usually, as sod's law says the
equipment on the bus will have failed when you really need something and
the police are standing next to you waiting..!) to download what is
needed and put it on a DVD or whatever. If it's out on the road, you
generally have to wait until it's back, hence it isn't possible to get
instant access.
For the purpose of a specific police operation, then they would follow a
bus in another vehicle and link directly to it, in this situation they
would be able to view the cameras live without being on the bus.
It *is* possible to view live camera feed from a moving vehicle back in
the garage, but it needs something like 4G fitted, which quite honestly
the company I worked for didn't feel was financially viable. Personally
I disagreed, but then I wasn't in charge of the budget.

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.

Roland Perry

2019-10-22 18:02:49 UTC

In message <qon9im$uuv$***@dont-email.me>, at 16:08:54 on Tue, 22 Oct
2019, Recliner <***@gmail.com> remarked:

[CCTV]

Post by Recliner
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.

--
Roland Perry

Recliner

2019-10-22 21:21:38 UTC

Post by Roland Perry
[CCTV]

Post by Recliner
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>

b***@nowhere.co.uk

2019-10-23 07:41:34 UTC

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

2019, Billy No Mates Always On His Own <Billy No Mates Always On His Own.usen
[CCTV]

Post by Recliner
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 A7Riiiâ¡ camera's RAW images are 41.3 MB, and it can
shoot 10Â 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.
<https://www.flickr.com/photos/Billy No Mates Always On His Own/albums/7215771

1379885958>

I wonder if dashcams storing low/uncompressed video is so it can accurately
capture very fast movement - eg just before an accident - which most video
compression systems are not particularly good at.

Roland Perry

2019-10-23 08:34:49 UTC

Post by b***@nowhere.co.uk
I wonder if dashcams storing low/uncompressed video is so it can accurately
capture very fast movement - eg just before an accident - which most video
compression systems are not particularly good at.

I think it's because they don't want to have the silicon|dollars|power
budget of compressing the video. They externalise it to users having to
buy stupidly big SD cards.

My previous dashcam gobbled through 1.2GB for each ten minute file.

--
Roland Perry

b***@nowhere.co.uk

2019-10-23 19:05:11 UTC

On Wed, 23 Oct 2019 09:34:49 +0100

I think it's because they don't want to have the silicon|dollars|power
budget of compressing the video. They externalise it to users having to
buy stupidly big SD cards.
My previous dashcam gobbled through 1.2GB for each ten minute file.

There must be more to it than that. Even cheap smartphones can do realtime
video compression. The hardware is probably commodity by now.

Roland Perry

2019-10-23 20:00:11 UTC

Post by b***@nowhere.co.uk
On Wed, 23 Oct 2019 09:34:49 +0100

I think it's because they don't want to have the silicon|dollars|power
budget of compressing the video. They externalise it to users having to
buy stupidly big SD cards.
My previous dashcam gobbled through 1.2GB for each ten minute file.

There must be more to it than that. Even cheap smartphones can do realtime
video compression.

They produce files in MP4 format, but not very much compressed. My phone
produces typically 150MB per minute (1920 x 1080 pixels).

Post by b***@nowhere.co.uk
The hardware is probably commodity by now.

My whole dashcam only cost about £30.

--
Roland Perry

Recliner

2019-10-23 20:37:27 UTC

Post by b***@nowhere.co.uk
On Wed, 23 Oct 2019 09:34:49 +0100

I think it's because they don't want to have the silicon|dollars|power
budget of compressing the video. They externalise it to users having to
buy stupidly big SD cards.
My previous dashcam gobbled through 1.2GB for each ten minute file.

There must be more to it than that. Even cheap smartphones can do realtime
video compression.

They produce files in MP4 format, but not very much compressed. My phone
produces typically 150MB per minute (1920 x 1080 pixels).

So, Full HD video.

Post by b***@nowhere.co.uk
The hardware is probably commodity by now.

My whole dashcam only cost about £30.

That doesn't leave much budget for the lens.

Roland Perry

2019-10-24 06:27:11 UTC

Post by b***@nowhere.co.uk
On Wed, 23 Oct 2019 09:34:49 +0100

I think it's because they don't want to have the silicon|dollars|power
budget of compressing the video. They externalise it to users having to
buy stupidly big SD cards.
My previous dashcam gobbled through 1.2GB for each ten minute file.

There must be more to it than that. Even cheap smartphones can do realtime
video compression.

They produce files in MP4 format, but not very much compressed. My phone
produces typically 150MB per minute (1920 x 1080 pixels).

So, Full HD video.

Like my dashcam (I presume the camera is essentially the same as that in
a phone).

Post by b***@nowhere.co.uk
The hardware is probably commodity by now.

My whole dashcam only cost about £30.

That doesn't leave much budget for the lens.

The lens is quite large (1.5cm), and wide angle (170 degrees). And yes,
it's probably one of the more expensive components.

But I run my dashcam at the lower setting of 720p, so that the SD card
fills up slower, which results in video a bit like this *after* it's
been cropped and re-compressed by video editing software to 30MB/min
@720p, and reprocessed by YouTube to 144-720p depending on the view you
select.

(Rail-related content)

--
Roland Perry

Graeme Wall

2019-10-24 07:47:39 UTC

Post by b***@nowhere.co.uk
On Wed, 23 Oct 2019 09:34:49 +0100

I think it's because they don't want to have the silicon|dollars|power
budget of compressing the video. They externalise it to users having to
buy stupidly big SD cards.
My previous dashcam gobbled through 1.2GB for each ten minute file.

There must be more to it than that. Even cheap smartphones can do realtime
video compression.

They produce files in MP4 format, but not very much compressed. My phone
produces typically 150MB per minute (1920 x 1080 pixels).

So, Full HD video.

Like my dashcam (I presume the camera is essentially the same as that in
a phone).

Post by b***@nowhere.co.uk
The hardware is probably commodity by now.

My whole dashcam only cost about £30.

That doesn't leave much budget for the lens.

The lens is quite large (1.5cm), and wide angle (170 degrees). And yes,
it's probably one of the more expensive components.
But I run my dashcam at the lower setting of 720p, so that the SD card
fills up slower, which results in video a bit like this *after* it's
been cropped and re-compressed by video editing software to 30MB/min
@720p, and reprocessed by YouTube to 144-720p depending on the view you
select.
http://youtu.be/F4aHaSyBHvE
(Rail-related content)

Nice view of the sky, you need to pan the camera down a bit to see more
of the road.

--
Graeme Wall
This account not read.

Roland Perry

2019-10-24 10:56:25 UTC

Post by Roland Perry
http://youtu.be/F4aHaSyBHvE
(Rail-related content)

Nice view of the sky, you need to pan the camera down a bit to see more
of the road.

If I pan it down much, then you get a great view of the bonnet.

The vertical wide angle is a consequence of the horizontal wide angle.
An alternative would be to letter-box crop the video.

I agree I don't think I've quite got the compromise completely right.

This is an alternative (but has the time/date which is distracting for
this kind of posting):

--
Roland Perry

Graeme Wall

2019-10-24 13:08:18 UTC

http://youtu.be/F4aHaSyBHvE
(Rail-related content)

Nice view of the sky, you need to pan the camera down a bit to see
more of the road.

If I pan it down much, then you get a great view of the bonnet.

Always a problem with those things.

Post by Roland Perry
The vertical wide angle is a consequence of the horizontal wide angle.
An alternative would be to letter-box crop the video.
I agree I don't think I've quite got the compromise completely right.

Does it actually have much in the way of adjustment or is it a ratchet
type arrangement where you pick the least worst spot?

--
Graeme Wall
This account not read.

Roland Perry

2019-10-24 13:35:30 UTC

http://youtu.be/F4aHaSyBHvE
(Rail-related content)

Nice view of the sky, you need to pan the camera down a bit to see
more of the road.

If I pan it down much, then you get a great view of the bonnet.

Always a problem with those things.

Post by Roland Perry
The vertical wide angle is a consequence of the horizontal wide
angle. An alternative would be to letter-box crop the video.
I agree I don't think I've quite got the compromise completely right.

Does it actually have much in the way of adjustment or is it a ratchet
type arrangement where you pick the least worst spot?

There are ratchet points, but somewhat a hostage to the fortune of the
rake of the windscreen.

--
Roland Perry

tim...

2019-10-25 13:45:36 UTC

Post by Roland Perry
http://youtu.be/F4aHaSyBHvE
(Rail-related content)

Nice view of the sky, you need to pan the camera down a bit to see more
of the road.

If I pan it down much, then you get a great view of the bonnet.

Always a problem with those things.

Does it actually have much in the way of adjustment or is it a ratchet
type arrangement where you pick the least worst spot?

There are ratchet points, but somewhat a hostage to the fortune of the
rake of the windscreen.

for me the problem was that, as I had overnight on-street parking, I didn't
want to leave it in place when parked in case some scrote broke in just to
steal the cam, so every time I went out I had to guess the correct place to
put it

And I'd be left will a bill to replace the window that's probably 3 or 4
times the value of the cam

tim

Roland Perry

2019-10-25 15:49:32 UTC

Post by Graeme Wall
Nice view of the sky, you need to pan the camera down a bit to see
more of the road.

If I pan it down much, then you get a great view of the bonnet.

Always a problem with those things.

Post by Roland Perry
The vertical wide angle is a consequence of the horizontal wide
angle. An alternative would be to letter-box crop the video.
I agree I don't think I've quite got the compromise completely right.

Does it actually have much in the way of adjustment or is it a
ratchet type arrangement where you pick the least worst spot?

There are ratchet points, but somewhat a hostage to the fortune of
the rake of the windscreen.

I leave the suction cup and stalk on the windscreen, and the camera just
clips to that. Very reliably/repeatably. If I had to adjust it daily it
would drive me potty.

Post by tim...
And I'd be left will a bill to replace the window that's probably 3 or
4 times the value of the cam

--
Roland Perry

MissRiaElaine

2019-10-25 16:40:30 UTC

Post by Roland Perry
I leave the suction cup and stalk on the windscreen, and the camera just
clips to that. Very reliably/repeatably. If I had to adjust it daily it
would drive me potty.

And said scrote, seeing the suction cup (or even if you did remove it,
the marks left by it, unless you cleaned the screen every time) would
break in looking to see if you'd hidden the camera somewhere.

--
Ria in Aberdeen

[Send address is invalid, use sipsoup at gmail dot com to reply direct]

Roland Perry

2019-10-25 16:47:03 UTC

Post by Roland Perry
I leave the suction cup and stalk on the windscreen, and the camera
just clips to that. Very reliably/repeatably. If I had to adjust it
daily it would drive me potty.

I don't think I've ever seen a car that appeared to have been broken
into like that. And for £39 of dashcam, would they bother?

--
Roland Perry

MissRiaElaine

2019-10-25 17:21:16 UTC

Post by Roland Perry
I leave the suction cup and stalk on the windscreen, and the camera
just clips to that. Very reliably/repeatably. If I had to adjust it
daily it would drive me potty.

I don't think I've ever seen a car that appeared to have been broken
into like that. And for £39 of dashcam, would they bother?

Because they're scrotes, it's what they do. They can sell it for a
tenner, enough for their next fix.

My car got broken into once because (I assume) they thought the glass
mounted aerial on the back window was connected to a (then common) fixed
car phone. It wasn't, it was for my 70cm amateur band radio, which I'd
taken with me.

--
Ria in Aberdeen

[Send address is invalid, use sipsoup at gmail dot com to reply direct]

Marland

2019-10-25 18:22:34 UTC

Post by Roland Perry
I leave the suction cup and stalk on the windscreen, and the camera
just clips to that. Very reliably/repeatably. If I had to adjust it
daily it would drive me potty.

I don't think I've ever seen a car that appeared to have been broken
into like that. And for £39 of dashcam, would they bother?

It was a common thing when satnavs first came in and were expensive,
now almost every vehicle has one or the driver uses a mobile phone there is
no market , so it is rare.
You would have to leave it in a real dodgy area for them to bother now, not
impossible but unlikely.

GH

David Cantrell

2019-10-28 09:50:59 UTC

Post by Roland Perry
I leave the suction cup and stalk on the windscreen, and the camera just
clips to that. Very reliably/repeatably. If I had to adjust it daily it
would drive me potty.

Not in my experience. I've had one of those things attached to my
windscreen for years without any problems.

--
David Cantrell | even more awesome than a panda-fur coat

MissRiaElaine

2019-10-28 17:42:06 UTC

Post by Roland Perry
I leave the suction cup and stalk on the windscreen, and the camera just
clips to that. Very reliably/repeatably. If I had to adjust it daily it
would drive me potty.

Not in my experience. I've had one of those things attached to my
windscreen for years without any problems.

You obviously haven't parked in some of the areas of Birmingham that I
have, then. They'd have your car stripped bare and standing on bricks
before you got back if you weren't careful.

--
Ria in Aberdeen

[Send address is invalid, use sipsoup at gmail dot com to reply direct]

Marland

2019-10-28 20:54:52 UTC

Post by Roland Perry
I leave the suction cup and stalk on the windscreen, and the camera just
clips to that. Very reliably/repeatably. If I had to adjust it daily it
would drive me potty.

Not in my experience. I've had one of those things attached to my
windscreen for years without any problems.

You obviously haven't parked in some of the areas of Birmingham that I
have, then. They'd have your car stripped bare and standing on bricks
before you got back if you weren't careful.

Seems a lot of work just to get a dash cam.

In practise every large conurbation will have areas where it will not be
wise to leave a vehicle unattended without precautions but for most that
isn’t day to day life and isn’t in the same league as parking in the car
park of Sainsbury’s .

GH

Roland Perry

2019-10-24 15:03:49 UTC

Post by Graeme Wall
Nice view of the sky, you need to pan the camera down a bit to see more
of the road.

How about this (without stabilisation):

Doesn't really convey the bumps adequately. Suffice it to say they are
30mph max in a car, and used to be 60mph in a 4x4, but are now more like
50mph. Picked today because of the 4x4 coming in the opposite direction.

--
Roland Perry

Graeme Wall

2019-10-24 15:53:33 UTC

Post by Graeme Wall
Nice view of the sky, you need to pan the camera down a bit to see
more of the road.

http://youtu.be/ExWe0kjE6Ns
Doesn't really convey the bumps adequately. Suffice it to say they are
30mph max in a car, and used to be 60mph in a 4x4, but are now more like
50mph. Picked today because of the 4x4 coming in the opposite direction.

Looks better, a more natural drivers eye view!

--
Graeme Wall
This account not read.

Roland Perry

2019-10-24 19:57:56 UTC

Post by Graeme Wall
Nice view of the sky, you need to pan the camera down a bit to see
more of the road.

http://youtu.be/ExWe0kjE6Ns
Doesn't really convey the bumps adequately. Suffice it to say they
are 30mph max in a car, and used to be 60mph in a 4x4, but are now
more like 50mph. Picked today because of the 4x4 coming in the
opposite direction.

Looks better, a more natural drivers eye view!

A lot of that comes from cropping the excessively wide-angle original
video. On the other hand, if the video is to show what happened in an
accident, you do need as wide an angle as possible.

--
Roland Perry

Graeme Wall

2019-10-24 20:22:40 UTC

Post by Graeme Wall
Nice view of the sky, you need to pan the camera down a bit to see
more of the road.

http://youtu.be/ExWe0kjE6Ns
Doesn't really convey the bumps adequately. Suffice it to say they
are 30mph max in a car, and used to be 60mph in a 4x4, but are now
more like 50mph. Picked today because of the 4x4 coming in the
opposite direction.

Looks better, a more natural drivers eye view!

A lot of that comes from cropping the excessively wide-angle original
video. On the other hand, if the video is to show what happened in an
accident, you do need as wide an angle as possible.

Very true.

--
Graeme Wall
This account not read.

tim...

2019-10-24 08:18:00 UTC

Post by b***@nowhere.co.uk
On Wed, 23 Oct 2019 09:34:49 +0100

I think it's because they don't want to have the silicon|dollars|power
budget of compressing the video. They externalise it to users having to
buy stupidly big SD cards.
My previous dashcam gobbled through 1.2GB for each ten minute file.

There must be more to it than that. Even cheap smartphones can do realtime
video compression.

They produce files in MP4 format, but not very much compressed. My phone
produces typically 150MB per minute (1920 x 1080 pixels).

So, Full HD video.

Like my dashcam (I presume the camera is essentially the same as that in a
phone).

Post by b***@nowhere.co.uk
The hardware is probably commodity by now.

My whole dashcam only cost about £30.

That doesn't leave much budget for the lens.

The lens is quite large (1.5cm), and wide angle (170 degrees). And yes,
it's probably one of the more expensive components.

I don't see why

non focusing, non zoom-able lenses cost pennies to make

tim

Recliner

2019-10-24 08:33:02 UTC

Post by b***@nowhere.co.uk
On Wed, 23 Oct 2019 09:34:49 +0100

I think it's because they don't want to have the silicon|dollars|power
budget of compressing the video. They externalise it to users having to
buy stupidly big SD cards.
My previous dashcam gobbled through 1.2GB for each ten minute file.

There must be more to it than that. Even cheap smartphones can do realtime
video compression.

They produce files in MP4 format, but not very much compressed. My phone
produces typically 150MB per minute (1920 x 1080 pixels).

So, Full HD video.

Like my dashcam (I presume the camera is essentially the same as that in a
phone).

Post by b***@nowhere.co.uk
The hardware is probably commodity by now.

My whole dashcam only cost about £30.

That doesn't leave much budget for the lens.

The lens is quite large (1.5cm), and wide angle (170 degrees). And yes,
it's probably one of the more expensive components.

I don't see why
non focusing, non zoom-able lenses cost pennies to make

It's still a high precision optical component, probably with four or five
elements, at least one of which is probably glass. Would it also have
aperture blades?

tim...

2019-10-24 09:08:05 UTC

Post by b***@nowhere.co.uk
On Wed, 23 Oct 2019 09:34:49 +0100

Post by b***@nowhere.co.uk
I wonder if dashcams storing low/uncompressed video is so it can accurately
capture very fast movement - eg just before an accident - which
most
video
compression systems are not particularly good at.

I think it's because they don't want to have the
silicon|dollars|power
budget of compressing the video. They externalise it to users having to
buy stupidly big SD cards.
My previous dashcam gobbled through 1.2GB for each ten minute file.

There must be more to it than that. Even cheap smartphones can do realtime
video compression.

They produce files in MP4 format, but not very much compressed. My phone
produces typically 150MB per minute (1920 x 1080 pixels).

So, Full HD video.

Like my dashcam (I presume the camera is essentially the same as that in a
phone).

Post by b***@nowhere.co.uk
The hardware is probably commodity by now.

My whole dashcam only cost about £30.

That doesn't leave much budget for the lens.

The lens is quite large (1.5cm), and wide angle (170 degrees). And yes,
it's probably one of the more expensive components.

I don't see why
non focusing, non zoom-able lenses cost pennies to make

It's still a high precision optical component, probably with four or five
elements, at least one of which is probably glass. Would it also have

not the one on mine

a single moulded item

Post by Recliner
aperture blades?

that is behind the glass not within the glass

Recliner

2019-10-24 09:41:10 UTC

Post by b***@nowhere.co.uk
On Wed, 23 Oct 2019 09:34:49 +0100

Post by b***@nowhere.co.uk
I wonder if dashcams storing low/uncompressed video is so it can accurately
capture very fast movement - eg just before an accident - which
most
video
compression systems are not particularly good at.

I think it's because they don't want to have the
silicon|dollars|power
budget of compressing the video. They externalise it to users having to
buy stupidly big SD cards.
My previous dashcam gobbled through 1.2GB for each ten minute file.

There must be more to it than that. Even cheap smartphones can do realtime
video compression.

They produce files in MP4 format, but not very much compressed. My phone
produces typically 150MB per minute (1920 x 1080 pixels).

So, Full HD video.

Like my dashcam (I presume the camera is essentially the same as that in a
phone).

Post by b***@nowhere.co.uk
The hardware is probably commodity by now.

My whole dashcam only cost about £30.

That doesn't leave much budget for the lens.

The lens is quite large (1.5cm), and wide angle (170 degrees). And yes,
it's probably one of the more expensive components.

I don't see why
non focusing, non zoom-able lenses cost pennies to make

It's still a high precision optical component, probably with four or five
elements, at least one of which is probably glass. Would it also have

not the one on mine
a single moulded item

I'd be very, very surprised. You'd get horrible image quality, unacceptable
even for a dashcam, with such a basic, single element lens. The elements
may be moulded plastic, but there are almost certainly several of them.

Post by Recliner
aperture blades?

that is behind the glass not within the glass

In all my many cameras and lenses, the aperture blades are between the lens
glass elements. But a small, cheap lens like this may have a fixed
aperture, with sensitivity controlled electronically. I also assume there's
no image stabilisation in such a cheap model.

Roland Perry

2019-10-24 11:01:02 UTC

Post by Recliner
In all my many cameras and lenses, the aperture blades are between the lens
glass elements. But a small, cheap lens like this may have a fixed
aperture, with sensitivity controlled electronically.

It's much better after-dark than I was expecting. Quite an impressive
dynamic range.

Post by Recliner
I also assume there's no image stabilisation in such a cheap model.

That would require extra processing power.

My PC-based editing software will do image stabilisation
post-processing, but to some extent the "wobble", or perhaps lack of, as
the car goes over the level crossing [at 30.0mph] in that video is part
of the experience I'm trying to capture.

--
Roland Perry

Recliner

2019-10-24 11:27:08 UTC

It's much better after-dark than I was expecting. Quite an impressive
dynamic range.

Post by Recliner
I also assume there's no image stabilisation in such a cheap model.

That would require extra processing power.
My PC-based editing software will do image stabilisation
post-processing, but to some extent the "wobble", or perhaps lack of, as
the car goes over the level crossing [at 30.0mph] in that video is part
of the experience I'm trying to capture.

I think small, cheap cameras have no moving parts, so no optical IS, no
mechanical shutter, no aperture blades, no lens cover, fixed focus and no
optical zoom. More expensive dash cams might include some of these 'luxury
features'.

David Cantrell

2019-10-25 09:04:38 UTC

Would it also have aperture blades?

No. Partly because that's complicated and expensive and moving parts are
likely to break, partly because you don't want the depth of field to
change based on how bright it is. It'll use some combination of fiddling
with exposure time and CCD sensitivity, all of which is purely done in
software, to control brightness.

--
David Cantrell | Cake Smuggler Extraordinaire

Human Rights left unattended may be removed,
destroyed, or damaged by the security services.

Recliner

2019-10-25 09:06:20 UTC

Would it also have aperture blades?

Yes, that's what I expected.

Graeme Wall

2019-10-24 08:44:22 UTC

Post by b***@nowhere.co.uk
On Wed, 23 Oct 2019 09:34:49 +0100

I think it's because they don't want to have the
silicon|dollars|power
budget of compressing the video. They externalise it to users having to
buy stupidly big SD cards.
My previous dashcam gobbled through 1.2GB for each ten minute file.

There must be more to it than that. Even cheap smartphones can do realtime
video compression.

They produce files in MP4 format, but not very much compressed. My phone
produces typically 150MB per minute (1920 x 1080 pixels).

So, Full HD video.

Like my dashcam (I presume the camera is essentially the same as that
in a phone).

Post by b***@nowhere.co.uk
The hardware is probably commodity by now.

My whole dashcam only cost about £30.

That doesn't leave much budget for the lens.

The lens is quite large (1.5cm), and wide angle (170 degrees). And
yes, it's probably one of the more expensive components.

I don't see why
non focusing, non zoom-able lenses cost pennies to make

The rest of the components probably cost fractions of a penny to make :-)

--
Graeme Wall
This account not read.

tim...

2019-10-24 09:11:34 UTC

Post by b***@nowhere.co.uk
On Wed, 23 Oct 2019 09:34:49 +0100

I think it's because they don't want to have the
silicon|dollars|power
budget of compressing the video. They externalise it to users having to
buy stupidly big SD cards.
My previous dashcam gobbled through 1.2GB for each ten minute file.

There must be more to it than that. Even cheap smartphones can do realtime
video compression.

They produce files in MP4 format, but not very much compressed. My phone
produces typically 150MB per minute (1920 x 1080 pixels).

So, Full HD video.

Like my dashcam (I presume the camera is essentially the same as that in
a phone).

Post by b***@nowhere.co.uk
The hardware is probably commodity by now.

My whole dashcam only cost about £30.

That doesn't leave much budget for the lens.

The lens is quite large (1.5cm), and wide angle (170 degrees). And yes,
it's probably one of the more expensive components.

I don't see why
non focusing, non zoom-able lenses cost pennies to make

The rest of the components probably cost fractions of a penny to make :-)

like all ICs

but they tend to cost dollars to buy

Not worked on this product class, not sure if this will be single chip
solution or not?

I have an unused one sitting on my shelf that I can't "give away" [1],
perhaps I'll break it down

tim

[1] to someone deserved of being give it

Guy Gorton

2019-10-23 16:48:02 UTC

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

Post by Roland Perry
[CCTV]

Post by Recliner
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.
<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

David Cantrell

2019-10-24 11:23:32 UTC

Post by Recliner
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.

I think that shows it's quite some time since you were on the
naughtynet! Looking at dodgy copies of rugby world cup quarter finals
highlights as an example, in the list I'm looking at right now no-one is
offering files that highly-compressed. Of those that are on offer, the
least popular is the most compressed (348MB for 32 minutes) and the most
popular is the least compressed (1.56GB for 32 minutes).

--
David Cantrell | Official London Perl Mongers Bad Influence

Longum iter est per praecepta, breve et efficax per exempla.

Roland Perry

2019-10-24 13:09:26 UTC

Post by Recliner
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.

For the majority of TV soap operas, what we once might have described as
"VHS quality" is entirely adequate for viewers to follow the [rather
weak in many cases] plotline|story-arc.

--
Roland Perry

Recliner

2019-10-24 15:08:47 UTC

Post by Recliner
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.

For the majority of TV soap operas, what we once might have described as
"VHS quality" is entirely adequate for viewers to follow the [rather
weak in many cases] plotline|story-arc.

Yes, but not if they're shown on 55" TVs. People now expect HD
quality.

Roland Perry

2019-10-24 15:22:05 UTC

Post by Roland Perry
For the majority of TV soap operas, what we once might have described as
"VHS quality" is entirely adequate for viewers to follow the [rather
weak in many cases] plotline|story-arc.

Yes, but not if they're shown on 55" TVs. People now expect HD
quality.

I didn't expect the Spanish Inquisition.

--
Roland Perry

Arthur Conan Doyle

2019-10-24 19:53:42 UTC

Post by Roland Perry
I didn't expect the Spanish Inquisition.

Nobody expects the Spanish Inquisition! (Sorry - I had to.)

Graeme Wall

2019-10-24 20:22:08 UTC

Post by Arthur Conan Doyle

Post by Roland Perry
I didn't expect the Spanish Inquisition.

Nobody expects the Spanish Inquisition! (Sorry - I had to.)

Cardinal Biggles I assume?

--
Graeme Wall
This account not read.

Arthur Conan Doyle

2019-10-25 12:37:28 UTC

Post by Arthur Conan Doyle
Nobody expects the Spanish Inquisition! (Sorry - I had to.)

Cardinal Biggles I assume?

Monty Python -

Graeme Wall

2019-10-25 22:36:36 UTC

Post by Arthur Conan Doyle

Post by Arthur Conan Doyle
Nobody expects the Spanish Inquisition! (Sorry - I had to.)

Cardinal Biggles I assume?

Monty Python - http://youtu.be/sAn7baRbhx4

I know, I was there!

--
Graeme Wall
This account not read.

Arthur Conan Doyle

2019-10-26 03:49:05 UTC

Post by Arthur Conan Doyle

Post by Arthur Conan Doyle
Nobody expects the Spanish Inquisition! (Sorry - I had to.)

Cardinal Biggles I assume?

Monty Python - http://youtu.be/sAn7baRbhx4

I know, I was there!

Of course! Totally forgot.

David Cantrell

2019-10-24 22:59:30 UTC

Post by David Cantrell
I think that shows it's quite some time since you were on the
naughtynet! Looking at dodgy copies of rugby world cup quarter finals
highlights as an example, in the list I'm looking at right now no-one is
offering files that highly-compressed. Of those that are on offer, the
least popular is the most compressed (348MB for 32 minutes) and the most
popular is the least compressed (1.56GB for 32 minutes).

For the majority of TV soap operas, what we once might have described as
"VHS quality" is entirely adequate for viewers to follow the [rather
weak in many cases] plotline|story-arc.

Just because that may be sufficient (of course a text file reading "it's
shit, get a life" would be too) doesn't mean that that's what people
actually download. The only content you'll regularly run across at low
resolution and heavily compressed is *old* content.

--
David Cantrell | http://www.cantrell.org.uk/david

Do not be afraid of cooking, as your ingredients will know and misbehave
-- Fergus Henderson

Roland Perry

2019-10-25 14:35:14 UTC

For the majority of TV soap operas, what we once might have described as
"VHS quality" is entirely adequate for viewers to follow the [rather
weak in many cases] plotline|story-arc.

Is that because the originators can't be bothered to compress it
properly, or is it in fact compressed quite a lot, but is *also* very
high definition?

I haven't got a lot of examples, but one is a well known 1280x720 TV
whodunnit show where they get 1.5hrs into 1.2GB

--
Roland Perry

MissRiaElaine

2019-10-22 18:15:01 UTC

Post by Recliner
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.

I doubt it, they were still installing them when I left in 2015. They
were still running Office 2003 on the network as well, they never were
at the forefront of Information Technology..! They didn't fully get rid
of VHS tapes until around the time I left.

--
Ria in Aberdeen

[Send address is invalid, use sipsoup at gmail dot com to reply direct]

tim...

2019-10-22 16:49:17 UTC

The bus has an onboard HDD recorder which has capacity to hold footage for
around a month or so. The way it usually works (or did with us) is that
under normal circumstances, these are recording all the time that the bus
is active, from the moment the engine is started to a preset period (a
couple of hours or so) after it is switched off.
When the bus returns to garage at the end of the day, any incidents that
have been requested will be downloaded to the server. The whole of the
contents of the buses' HDD's will not be downloaded, this would just be a
waste of time, as for 99% of the time nothing important is happening. You
only need to download what you need to investigate any particular incident
that has been reported. If the bus happens to be in the garage, then it's
usually quite easy (I say usually, as sod's law says the equipment on the
bus will have failed when you really need something and the police are
standing next to you waiting..!) to download what is needed and put it on
a DVD or whatever. If it's out on the road, you generally have to wait
until it's back, hence it isn't possible to get instant access.

very useful, but

I don't know who saw the program - no one has commented,

though (with exception of the previously referred to police incident) most
of the incidents highlighted were office staff (or more likely now,
automated systems) determining that particular Oyster cards as suspected of
being used to travel long, or dumbelling. Historic CCTV data (some of which
was from bus journeys) was used to capture images of the suspected
miscreant. Thus the actual CCTV footage viewed could be weeks old.

RPIs were then show on the lookout for that person the next time they went
through a barrier at the expected time (as you might imagine, not with 100%
success)

For the purpose of a specific police operation, then they would follow a
bus in another vehicle and link directly to it, in this situation they
would be able to view the cameras live without being on the bus.

The TV incident was "immediate"

tim

tim...

2019-10-22 14:22:48 UTC

Post by tim...
Did others see this?
Not that you need to have done to answer my question
The program appeared to show the roving RPIs/Police Offices had real time
access to the CCTV inside a specific bus (that they weren't riding on).
Do they really have that capability?
Or was this just post editing of the program to pretend that they did?

You've just answered your question.

No, I haven't

the dialogue definitely suggested that the RPI was seeing the same video we
did

And it's obviously, in this technological era, technically possible

so the only question is, do the RPIs actually have the equipment to allow
it?

And given that one of the reasons why the Airwave replacement has been
delayed is because they haven't (yet) implemented the replay of video, No
wouldn't be a surprise.

But OTOH, as TfL's equipment probably doesn't have to have the same levels
of security as Police Systems require, it could be possible with off the
shelf devices.

tim

Post by Graeme Wall
--
Graeme Wall
This account not read.

Graeme Wall

2019-10-22 15:49:56 UTC