<s>
A	O
digital	B-Application
video	I-Application
recorder	I-Application
(	O
DVR	O
)	O
is	O
an	O
electronic	O
device	O
that	O
records	O
video	O
in	O
a	O
digital	B-General_Concept
format	I-General_Concept
to	O
a	O
disk	B-Device
drive	I-Device
,	O
USB	O
flash	O
drive	O
,	O
SD	B-Device
memory	I-Device
card	I-Device
,	O
SSD	B-Device
or	O
other	O
local	O
or	O
networked	O
mass	B-Device
storage	I-Device
device	I-Device
.	O
</s>
<s>
The	O
term	O
includes	O
set-top	O
boxes	O
with	O
direct	O
to	O
disk	B-Device
recording	O
,	O
portable	O
media	O
players	O
and	O
TV	B-Device
gateways	I-Device
with	O
recording	O
capability	O
,	O
and	O
digital	B-General_Concept
camcorders	O
.	O
</s>
<s>
Personal	B-Device
computers	I-Device
are	O
often	O
connected	O
to	O
video	B-General_Concept
capture	I-General_Concept
devices	O
and	O
used	O
as	O
DVRs	O
;	O
in	O
such	O
cases	O
the	O
application	B-Application
software	I-Application
used	O
to	O
record	O
video	O
is	O
an	O
integral	O
part	O
of	O
the	O
DVR	O
.	O
</s>
<s>
Many	O
DVRs	O
are	O
classified	O
as	O
consumer	O
electronic	O
devices	O
;	O
such	O
devices	O
may	O
alternatively	O
be	O
referred	O
to	O
as	O
personal	B-Application
video	I-Application
recorders	I-Application
(	O
PVRs	O
)	O
,	O
particularly	O
in	O
Canada	O
.	O
</s>
<s>
Similar	O
small	O
devices	O
with	O
built-in	O
(	O
~	O
5	O
inch	O
diagonal	O
)	O
displays	O
and	O
SSD	B-Device
support	O
may	O
be	O
used	O
for	O
professional	O
film	O
or	O
video	O
production	O
,	O
as	O
these	O
recorders	O
often	O
do	O
not	O
have	O
the	O
limitations	O
that	O
built-in	O
recorders	O
in	O
cameras	O
have	O
,	O
offering	O
wider	O
codec	O
support	O
,	O
the	O
removal	O
of	O
recording	O
time	O
limitations	O
and	O
higher	O
bitrates	O
.	O
</s>
<s>
The	O
prototype	O
was	O
developed	O
in	O
1998	O
at	O
Prof	O
.	O
Pat	O
Hanrahan	O
's	O
CS488	O
class	O
:	O
Experiments	O
in	O
Digital	B-Application
Television	I-Application
,	O
and	O
the	O
prototype	O
was	O
demoed	O
to	O
industrial	O
partners	O
including	O
SONY	O
,	O
Intel	O
,	O
and	O
Apple	O
.	O
</s>
<s>
Consumer	O
digital	B-Application
video	I-Application
recorders	I-Application
ReplayTV	B-Device
and	O
TiVo	B-Application
were	O
launched	O
at	O
the	O
1999	O
Consumer	O
Electronics	O
Show	O
in	O
Las	O
Vegas	O
,	O
Nevada	O
.	O
</s>
<s>
Microsoft	O
also	O
demonstrated	O
a	O
unit	O
with	O
DVR	O
capability	O
,	O
but	O
this	O
did	O
not	O
become	O
available	O
until	O
the	O
end	O
of	O
1999	O
for	O
full	O
DVR	O
features	O
in	O
Dish	O
Network	O
's	O
DISHplayer	O
receivers	B-Device
.	O
</s>
<s>
TiVo	B-Application
shipped	O
their	O
first	O
units	O
on	O
March	O
31	O
,	O
1999	O
.	O
</s>
<s>
ReplayTV	B-Device
won	O
the	O
"	O
Best	O
of	O
Show	O
"	O
award	O
in	O
the	O
video	O
category	O
with	O
Netscape	B-Protocol
co-founder	O
Marc	O
Andreessen	O
as	O
an	O
early	O
investor	O
and	O
board	O
member	O
,	O
but	O
TiVo	B-Application
was	O
more	O
successful	O
commercially	O
.	O
</s>
<s>
Legal	O
action	O
by	O
media	O
companies	O
forced	O
ReplayTV	B-Device
to	O
remove	O
many	O
features	O
such	O
as	O
automatic	O
commercial	B-Application
skip	O
and	O
the	O
sharing	O
of	O
recordings	O
over	O
the	O
Internet	O
,	O
but	O
newer	O
devices	O
have	O
steadily	O
regained	O
these	O
functions	O
while	O
adding	O
complementary	O
abilities	O
,	O
such	O
as	O
recording	O
onto	O
DVDs	O
and	O
programming	O
and	O
remote	B-Protocol
control	I-Protocol
facilities	O
using	O
PDAs	O
,	O
networked	O
PCs	B-Device
,	O
and	O
Web	O
browsers	O
.	O
</s>
<s>
In	O
contrast	O
to	O
VCRs	O
,	O
hard-disk	B-Device
based	O
digital	B-Application
video	I-Application
recorders	I-Application
make	O
"	O
time	B-Device
shifting	I-Device
"	O
more	O
convenient	O
and	O
also	O
allow	O
for	O
functions	O
such	O
as	O
pausing	O
live	O
TV	O
,	O
instant	O
replay	O
,	O
chasing	B-Device
playback	I-Device
(	O
viewing	O
a	O
recording	O
before	O
it	O
has	O
been	O
completed	O
)	O
and	O
skipping	O
over	O
advertising	O
during	O
playback	O
.	O
</s>
<s>
Many	O
DVRs	O
use	O
the	O
MPEG	O
format	O
for	O
compressing	O
the	O
digital	B-General_Concept
video	O
.	O
</s>
<s>
As	O
consumers	O
have	O
been	O
able	O
to	O
converge	O
increasing	O
amounts	O
of	O
video	O
content	O
on	O
their	O
set-tops	O
,	O
delivered	O
by	O
traditional	O
'	O
broadcast	B-Operating_System
 '	O
cable	O
,	O
satellite	O
and	O
terrestrial	O
as	O
well	O
as	O
IP	B-Protocol
networks	O
,	O
the	O
ability	O
to	O
capture	O
programming	O
and	O
view	O
it	O
whenever	O
they	O
want	O
has	O
become	O
a	O
must-have	O
function	O
for	O
many	O
consumers	O
.	O
</s>
<s>
At	O
the	O
1999	O
CES	O
,	O
Dish	O
Network	O
demonstrated	O
the	O
hardware	B-Architecture
that	O
would	O
later	O
have	O
DVR	O
capability	O
with	O
the	O
assistance	O
of	O
Microsoft	O
software	O
.	O
</s>
<s>
In	O
the	O
UK	O
,	O
digital	B-Application
video	I-Application
recorders	I-Application
are	O
often	O
referred	O
to	O
as	O
"	O
plus	O
boxes	O
"	O
(	O
such	O
as	O
BSKYB	O
's	O
Sky+	O
and	O
Virgin	O
Media	O
's	O
V+	B-Device
which	O
integrates	O
an	O
HD	B-Device
capability	O
,	O
and	O
the	O
subscription	O
free	B-Application
Freesat+	B-Device
and	O
Freeview+	O
)	O
.	O
</s>
<s>
British	O
Sky	O
Broadcasting	B-Operating_System
marketed	O
a	O
popular	O
combined	O
receiver	B-Device
and	O
DVR	O
as	O
Sky+	O
,	O
now	O
replaced	O
by	O
the	O
Sky	O
Q	O
box	O
.	O
</s>
<s>
TiVo	B-Application
launched	O
a	O
UK	O
model	O
in	O
2000	O
,	O
and	O
is	O
no	O
longer	O
supported	O
,	O
except	O
for	O
third	O
party	O
services	O
,	O
and	O
the	O
continuation	O
of	O
TiVo	B-Application
through	O
Virgin	O
Media	O
in	O
2010	O
.	O
</s>
<s>
In	O
addition	O
to	O
ReplayTV	B-Device
and	O
TiVo	B-Application
,	O
there	O
are	O
a	O
number	O
of	O
other	O
suppliers	O
of	O
digital	B-Application
terrestrial	I-Application
(	O
DTT	B-Application
)	O
DVRs	O
,	O
including	O
Technicolor	O
SA	O
,	O
Topfield	O
,	O
Fusion	O
,	O
Commscope	O
,	O
Humax	O
,	O
VBox	B-Device
Communications	O
,	O
AC	O
Ryan	O
Playon	O
and	O
Advanced	O
Digital	B-General_Concept
Broadcast	B-Operating_System
(	O
ADB	O
)	O
.	O
</s>
<s>
Many	O
satellite	O
,	O
cable	O
and	O
IPTV	O
companies	O
are	O
incorporating	O
digital	B-Application
video	I-Application
recording	I-Application
functions	O
into	O
their	O
set-top	O
box	O
,	O
such	O
as	O
with	O
DirecTiVo	B-Device
,	O
DISHPlayer/DishDVR	O
,	O
Scientific	O
Atlanta	O
Explorer	O
8xxx	O
from	O
Time	O
Warner	O
,	O
Total	O
Home	O
DVR	O
from	O
AT&T	O
U-verse	O
,	O
Motorola	O
DCT6412	O
from	O
Comcast	O
and	O
others	O
,	O
Moxi	B-Device
Media	I-Device
Center	I-Device
by	O
Digeo	B-Device
(	O
available	O
through	O
Charter	O
,	O
Adelphia	O
,	O
Sunflower	O
,	O
Bend	O
Broadband	O
,	O
and	O
soon	O
Comcast	O
and	O
other	O
cable	O
companies	O
)	O
,	O
or	O
Sky+	O
.	O
</s>
<s>
In	O
the	O
case	O
of	O
digital	B-Application
television	I-Application
,	O
there	O
is	O
no	O
encoding	O
necessary	O
in	O
the	O
DVR	O
since	O
the	O
signal	O
is	O
already	O
a	O
digitally	O
encoded	O
MPEG	O
stream	O
.	O
</s>
<s>
The	O
digital	B-Application
video	I-Application
recorder	I-Application
simply	O
stores	O
the	O
digital	B-General_Concept
stream	O
directly	O
to	O
disk	B-Device
.	O
</s>
<s>
Having	O
the	O
broadcaster	O
involved	O
with	O
,	O
and	O
sometimes	O
subsidizing	O
,	O
the	O
design	O
of	O
the	O
DVR	O
can	O
lead	O
to	O
features	O
such	O
as	O
the	O
ability	O
to	O
use	O
interactive	O
TV	O
on	O
recorded	O
shows	O
,	O
pre-loading	O
of	O
programs	O
,	O
or	O
directly	O
recording	O
encrypted	O
digital	B-General_Concept
streams	O
.	O
</s>
<s>
In	O
the	O
United	O
States	O
,	O
the	O
FCC	O
has	O
ruled	O
that	O
starting	O
on	O
July	O
1	O
,	O
2007	O
,	O
consumers	O
will	O
be	O
able	O
to	O
purchase	O
a	O
set-top	O
box	O
from	O
a	O
third-party	B-General_Concept
company	O
,	O
rather	O
than	O
being	O
forced	O
to	O
purchase	O
or	O
rent	O
the	O
set-top	O
box	O
from	O
their	O
cable	O
company	O
.	O
</s>
<s>
The	O
overall	O
net	O
effect	O
on	O
digital	B-Application
video	I-Application
recorders	I-Application
and	O
related	O
technology	O
is	O
unlikely	O
to	O
be	O
substantial	O
as	O
standalone	O
DVRs	O
are	O
currently	O
readily	O
available	O
on	O
the	O
open	O
market	O
.	O
</s>
<s>
In	O
Europe	O
Free-To-Air	O
and	O
Pay	O
TV	O
TV	B-Device
gateways	I-Device
with	O
multiple	O
tuners	B-Device
have	O
whole	O
house	O
recording	O
capabilities	O
allowing	O
recording	O
of	O
TV	O
programs	O
to	O
Network	B-Application
Attached	I-Application
Storage	I-Application
or	O
attached	O
USB	O
storage	O
,	O
recorded	O
programs	O
are	O
then	O
shared	O
across	O
the	O
home	O
network	O
to	O
tablet	B-Device
,	O
smartphone	B-Application
,	O
PC	O
,	O
Mac	O
,	O
Smart	B-Device
TV	I-Device
.	O
</s>
<s>
In	O
2003	O
many	O
Satellite	O
and	O
Cable	O
providers	O
introduced	O
dual-tuner	O
digital	B-Application
video	I-Application
recorders	I-Application
.	O
</s>
<s>
In	O
the	O
UK	O
,	O
BSkyB	O
introduced	O
their	O
first	O
PVR	O
Sky+	O
with	O
dual	O
tuner	B-Device
support	O
in	O
2001	O
.	O
</s>
<s>
These	O
machines	O
have	O
two	O
independent	O
tuners	B-Device
within	O
the	O
same	O
receiver	B-Device
.	O
</s>
<s>
Kogan.com	O
introduced	O
a	O
dual-tuner	O
PVR	O
in	O
the	O
Australian	O
market	O
allowing	O
free-to-air	O
television	O
to	O
be	O
recorded	O
on	O
a	O
removable	O
hard	B-Device
drive	I-Device
.	O
</s>
<s>
Some	O
dual-tuner	O
DVRs	O
also	O
have	O
the	O
ability	O
to	O
output	O
to	O
two	O
separate	O
television	O
sets	O
at	O
the	O
same	O
time	O
.	O
</s>
<s>
The	O
PVR	O
manufactured	O
by	O
UEC	O
(	O
Durban	O
,	O
South	O
Africa	O
)	O
and	O
used	O
by	O
Multichoice	O
and	O
Scientific	O
Atlanta	O
8300DVB	O
PVR	O
have	O
the	O
ability	O
to	O
view	O
two	O
programs	O
while	O
recording	O
a	O
third	O
using	O
a	O
triple	O
tuner	B-Device
.	O
</s>
<s>
Where	O
several	O
digital	B-Device
subchannels	I-Device
are	O
transmitted	O
on	O
a	O
single	O
RF	O
channel	O
,	O
some	O
PVRs	O
can	O
record	O
two	O
channels	O
and	O
view	O
a	O
third	O
,	O
so	O
long	O
as	O
all	O
three	O
subchannels	B-Device
are	O
on	O
two	O
channels	O
(	O
or	O
one	O
)	O
.	O
</s>
<s>
These	O
systems	O
simplify	O
wiring	O
and	O
operation	O
because	O
they	O
employ	O
a	O
single	O
power	O
cable	O
,	O
have	O
no	O
interconnected	O
ports	O
(	O
e.g.	O
,	O
HDMI	B-Protocol
)	O
,	O
and	O
share	O
a	O
common	O
remote	B-Protocol
control	I-Protocol
.	O
</s>
<s>
Over-the-air	O
DVRs	O
are	O
standalone	O
receivers	B-Device
that	O
record	O
broadcast	B-Operating_System
television	O
programs	O
.	O
</s>
<s>
Some	O
pay-TV	O
operators	O
provide	O
receivers	B-Device
that	O
allow	O
subscribers	O
to	O
attach	O
their	O
own	O
network-attached	B-Application
storage	I-Application
(	O
NAS	B-Application
)	O
hard	B-Device
drives	I-Device
or	O
solid-state	O
or	O
flash	B-Device
memory	I-Device
to	O
record	O
video	O
and	O
other	O
media	O
files	O
(	O
e.g.	O
,	O
audio	O
and	O
photos	O
)	O
.	O
</s>
<s>
Software	O
and	O
hardware	B-Architecture
are	O
available	O
which	O
can	O
turn	O
personal	B-Device
computers	I-Device
running	O
Microsoft	B-Application
Windows	I-Application
,	O
Linux	B-Application
,	O
and	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
into	O
DVRs	O
,	O
and	O
is	O
a	O
popular	O
option	O
for	O
home-theater	O
PC	O
(	O
HTPC	O
)	O
enthusiasts	O
.	O
</s>
<s>
There	O
are	O
many	O
free	B-Application
and	I-Application
open	I-Application
source	I-Application
software	I-Application
DVR	O
applications	O
available	O
for	O
Linux	B-Application
.	O
</s>
<s>
For	O
example	O
,	O
TV	B-Device
gateway	I-Device
interfaces	O
to	O
DVB	B-Application
tuners	B-Device
and	O
provides	O
network	O
tuner	B-Device
and	O
TV	O
server	O
functions	O
,	O
which	O
allows	O
live	O
viewing	O
and	O
recording	O
over	O
IP	B-Protocol
networks	O
.	O
</s>
<s>
Other	O
examples	O
include	O
MythTV	B-Application
,	O
Video	B-Application
Disk	I-Application
Recorder	I-Application
(	O
VDR	O
)	O
,	O
LinuxMCE	B-Application
,	O
TiVo	B-Application
,	O
VBox	B-Device
Home	I-Device
TV	I-Device
Gateway	I-Device
,	O
and	O
Kodi	B-Application
(	O
formerly	O
XBMC	B-Application
)	O
.	O
</s>
<s>
Geniatech	O
makes	O
a	O
series	O
of	O
digital	B-Application
video	I-Application
recording	I-Application
devices	O
called	O
EyeTV	O
.	O
</s>
<s>
The	O
software	O
supplied	O
with	O
each	O
device	O
is	O
also	O
called	O
EyeTV	O
,	O
and	O
is	O
available	O
separately	O
for	O
use	O
on	O
compatible	O
third-party	B-General_Concept
tuners	B-Device
from	O
manufacturers	O
such	O
as	O
Pinnacle	O
,	O
TerraTec	O
,	O
and	O
Hauppauge	O
.	O
</s>
<s>
SageTV	B-Device
provided	O
DVR	O
software	O
for	O
the	O
Mac	O
but	O
no	O
longer	O
sells	O
it	O
.	O
</s>
<s>
Previously	O
sold	O
devices	O
support	O
the	O
Hauppauge	O
HVR-950	O
,	O
myTV.PVR	O
and	O
HDHomeRun	O
hardware	B-Architecture
with	O
its	O
DVR	O
software	O
.	O
</s>
<s>
SageTV	B-Device
software	O
also	O
included	O
the	O
ability	O
to	O
watch	O
YouTube	O
and	O
other	O
online	O
video	O
with	O
a	O
remote	B-Protocol
control	I-Protocol
.	O
</s>
<s>
MythTV	B-Application
(	O
see	O
above	O
)	O
also	O
runs	O
under	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
,	O
but	O
most	O
recording	O
devices	O
are	O
currently	O
only	O
supported	O
under	O
Linux	B-Application
.	O
</s>
<s>
Precompiled	O
binaries	O
are	O
available	O
for	O
the	O
MythTV	B-Application
front-end	O
,	O
allowing	O
a	O
Mac	O
to	O
watch	O
video	O
from	O
(	O
and	O
control	O
)	O
a	O
MythTV	B-Application
server	O
running	O
under	O
Linux	B-Application
.	O
</s>
<s>
Apple	O
provides	O
applications	O
in	O
the	O
FireWire	O
software	O
developer	O
kit	O
which	O
allow	O
any	O
Mac	O
with	O
a	O
FireWire	O
port	O
to	O
record	O
the	O
MPEG2	B-Algorithm
transport	O
stream	O
from	O
a	O
FireWire-equipped	O
cable	O
box	O
(	O
for	O
example	O
:	O
Motorola	O
DCT62xx	O
,	O
including	O
HD	B-Device
streams	O
)	O
.	O
</s>
<s>
Only	O
broadcast	B-Operating_System
channels	O
can	O
be	O
recorded	O
as	O
the	O
rest	O
of	O
the	O
channels	O
are	O
encrypted	O
.	O
</s>
<s>
FireRecord	O
(	O
formerly	O
iRecord	O
)	O
is	O
a	O
free	B-Application
scheduled-recording	O
program	O
derived	O
from	O
this	O
SDK	O
.	O
</s>
<s>
There	O
are	O
several	O
free	B-Application
digital	B-Application
video	I-Application
recording	I-Application
applications	O
available	O
for	O
Microsoft	B-Application
Windows	I-Application
including	O
GB-PVR	O
,	O
MediaPortal	B-Application
,	O
and	O
Orb	B-Application
(	O
web-based	O
remote	O
interface	O
)	O
.	O
</s>
<s>
There	O
are	O
also	O
several	O
commercial	B-Application
applications	O
available	O
including	O
CyberLink	O
,	O
SageTV	B-Device
(	O
which	O
is	O
no	O
longer	O
available	O
after	O
Google	O
acquired	O
it	O
in	O
June	O
2011	O
)	O
,	O
Beyond	B-Device
TV	I-Device
(	O
which	O
is	O
considered	O
discontinued	O
despite	O
an	O
official	O
announcement	O
from	O
SnapStream	O
since	O
the	O
last	O
update	O
was	O
October	O
2010	O
and	O
they	O
are	O
concentrating	O
on	O
their	O
enterprise	O
search	O
products	O
)	O
,	O
DVBViewer	B-Device
,	O
Showshifter	B-Device
,	O
InterVideo	B-Device
WinDVR	I-Device
,	O
the	O
R5000-HD	O
and	O
Meedio	O
(	O
now	O
a	O
dead	O
product	O
–	O
Yahoo	O
!	O
</s>
<s>
Go	O
–	O
TV	O
,	O
which	O
is	O
now	O
a	O
free	B-Application
product	O
but	O
only	O
works	O
in	O
the	O
U.S.	O
)	O
.	O
</s>
<s>
Most	O
TV	B-Device
tuner	I-Device
cards	I-Device
come	O
bundled	O
with	O
software	O
which	O
allows	O
the	O
PC	O
to	O
record	O
television	O
to	O
hard	B-Device
disk	I-Device
.	O
</s>
<s>
See	O
TV	B-Device
tuner	I-Device
card	I-Device
.	O
</s>
<s>
For	O
example	O
,	O
Leadtek	O
's	O
WinFast	O
DTV1000	O
digital	B-Application
TV	I-Application
card	O
comes	O
bundled	O
with	O
the	O
WinFast	O
PVR2	O
software	O
,	O
which	O
can	O
also	O
record	O
analog	O
video	O
from	O
the	O
card	O
's	O
composite	O
video	O
input	O
socket	O
.	O
</s>
<s>
Windows	B-Device
Media	I-Device
Center	I-Device
is	O
a	O
DVR	O
software	O
by	O
Microsoft	O
which	O
was	O
bundled	O
with	O
the	O
Media	B-Application
Center	I-Application
edition	I-Application
of	I-Application
Windows	I-Application
XP	I-Application
,	O
the	O
Home	O
Premium	O
/	O
Ultimate	O
editions	O
of	O
Windows	B-Application
Vista	I-Application
,	O
as	O
well	O
as	O
most	O
editions	O
of	O
Windows	B-Device
7	I-Device
.	O
</s>
<s>
When	O
Windows	O
8	O
was	O
released	O
in	O
2012	O
,	O
Windows	B-Device
Media	I-Device
Center	I-Device
was	O
not	O
included	O
with	O
Windows	O
8	O
OEM	O
or	O
Retail	O
installations	O
,	O
and	O
was	O
only	O
available	O
as	O
a	O
$15	O
add-on	O
pack	O
(	O
including	O
DVD	O
Playback	O
codecs	O
)	O
to	O
Windows	O
8	O
Pro	O
users	O
.	O
</s>
<s>
Video	O
is	O
the	O
visual	O
portion	O
of	O
television	O
,	O
whereas	O
television	O
is	O
the	O
combination	O
of	O
video	O
and	O
audio	O
modulated	B-Application
onto	O
a	O
carrier	O
frequency	O
(	O
i.e.	O
,	O
a	O
television	O
channel	O
)	O
for	O
delivery	O
.	O
</s>
<s>
The	O
first	O
digital	B-Application
video	I-Application
recorders	I-Application
were	O
designed	O
to	O
record	O
analog	O
television	O
in	O
NTSC	O
,	O
PAL	B-Language
or	O
SECAM	O
formats	O
.	O
</s>
<s>
In	O
the	O
case	O
of	O
a	O
television	O
signal	O
,	O
a	O
television	B-Device
tuner	I-Device
must	O
first	O
demodulate	O
the	O
radio	O
frequency	O
signal	O
to	O
produce	O
baseband	O
video	O
.	O
</s>
<s>
The	O
video	O
is	O
then	O
converted	O
to	O
digital	B-General_Concept
form	O
by	O
a	O
frame	B-Device
grabber	I-Device
,	O
which	O
converts	O
each	O
video	O
image	O
into	O
a	O
collection	O
of	O
numeric	O
values	O
that	O
represent	O
the	O
pixels	B-Algorithm
within	O
the	O
image	O
.	O
</s>
<s>
At	O
the	O
same	O
time	O
,	O
the	O
audio	O
is	O
also	O
converted	O
to	O
digital	B-General_Concept
form	O
by	O
an	O
analog-to-digital	O
converter	O
running	O
at	O
a	O
constant	O
sampling	O
rate	O
.	O
</s>
<s>
In	O
many	O
devices	O
,	O
the	O
resulting	O
digital	B-General_Concept
video	O
and	O
audio	O
are	O
compressed	O
before	O
recording	O
to	O
reduce	O
the	O
amount	O
of	O
data	O
that	O
will	O
be	O
recorded	O
,	O
although	O
some	O
DVRs	O
record	O
uncompressed	O
data	O
.	O
</s>
<s>
When	O
compression	O
is	O
used	O
,	O
video	O
is	O
typically	O
compressed	O
using	O
formats	O
such	O
as	O
H.264	B-Application
or	O
MPEG-2	B-Algorithm
,	O
and	O
audio	O
is	O
compressed	O
using	O
AAC	O
or	O
MP3	B-Application
.	O
</s>
<s>
Many	O
consumer	O
DVRs	O
implement	O
a	O
copy-protection	B-Application
system	O
called	O
Copy	O
Generation	O
Management	O
System	O
—	O
Analog	O
(	O
CGMS-A	O
)	O
,	O
which	O
specifies	O
one	O
of	O
four	O
possible	O
copy	O
permissions	O
by	O
means	O
of	O
two	O
bits	O
encoded	O
in	O
the	O
vertical	O
blanking	O
interval	O
:	O
</s>
<s>
CGMS-A	O
information	O
may	O
be	O
present	O
in	O
analog	O
broadcast	B-Operating_System
TV	O
signals	O
,	O
and	O
is	O
preserved	O
when	O
the	O
signal	O
is	O
recorded	O
and	O
played	O
back	O
by	O
analog	O
VCRs	O
.	O
</s>
<s>
DVRs	O
such	O
as	O
TiVo	B-Application
also	O
detect	O
and	O
act	O
upon	O
analog	O
protection	O
systems	O
such	O
as	O
Macrovision	O
and	O
DCS	O
Copy	B-Application
Protection	I-Application
which	O
were	O
originally	O
designed	O
to	O
block	O
copying	O
on	O
analog	O
VCRs	O
.	O
</s>
<s>
Recording	O
digital	B-General_Concept
signals	O
is	O
generally	O
a	O
straightforward	O
capture	O
of	O
the	O
binary	O
MPEG	O
data	O
being	O
received	O
.	O
</s>
<s>
No	O
expensive	O
hardware	B-Architecture
is	O
required	O
to	O
quantize	B-Algorithm
and	O
compress	O
the	O
signal	O
(	O
as	O
the	O
television	B-Operating_System
broadcaster	I-Operating_System
has	O
already	O
done	O
this	O
in	O
the	O
studio	O
)	O
.	O
</s>
<s>
DVD-based	O
PVRs	O
available	O
on	O
the	O
market	O
as	O
of	O
2006	O
are	O
not	O
capable	O
of	O
capturing	O
the	O
full	O
range	O
of	O
the	O
visual	O
signal	O
available	O
with	O
high-definition	B-Device
television	I-Device
(	O
HDTV	B-Device
)	O
.	O
</s>
<s>
This	O
is	O
largely	O
because	O
HDTV	B-Device
standards	O
were	O
finalized	O
at	O
a	O
later	O
time	O
than	O
the	O
standards	O
for	O
DVDs	O
.	O
</s>
<s>
However	O
,	O
DVD-based	O
PVRs	O
can	O
still	O
be	O
used	O
(	O
albeit	O
at	O
reduced	O
visual	O
quality	O
)	O
with	O
HDTV	B-Device
since	O
currently	O
available	O
HDTV	B-Device
sets	O
also	O
have	O
standard	O
A/V	O
connections	O
.	O
</s>
<s>
ATSC	B-Device
television	O
broadcasting	B-Operating_System
is	O
primarily	O
used	O
in	O
North	O
America	O
.	O
</s>
<s>
The	O
ATSC	B-Device
data	O
stream	O
can	O
be	O
directly	O
recorded	O
by	O
a	O
digital	B-Application
video	I-Application
recorder	I-Application
,	O
though	O
many	O
DVRs	O
record	O
only	O
a	O
subset	O
of	O
this	O
information	O
(	O
that	O
can	O
later	O
be	O
transferred	O
to	O
DVD	O
)	O
.	O
</s>
<s>
An	O
ATSC	B-Device
DVR	O
will	O
also	O
act	O
as	O
a	O
set-top	O
box	O
,	O
allowing	O
older	O
televisions	O
or	O
monitors	O
to	O
receive	O
digital	B-Application
television	I-Application
.	O
</s>
<s>
The	O
U.S.	O
FCC	O
attempted	O
to	O
limit	O
the	O
abilities	O
of	O
DVRs	O
with	O
its	O
"	O
broadcast	B-Device
flag	I-Device
"	O
regulation	O
.	O
</s>
<s>
Digital	B-Application
video	I-Application
recorders	I-Application
that	O
had	O
not	O
won	O
prior	O
approval	O
from	O
the	O
FCC	O
for	O
implementing	O
"	O
effective	O
"	O
digital	B-General_Concept
rights	O
management	O
would	O
have	O
been	O
banned	O
from	O
interstate	O
commerce	O
from	O
July	O
2005	O
,	O
but	O
the	O
regulation	O
was	O
struck	O
down	O
on	O
May	O
6	O
,	O
2005	O
.	O
</s>
<s>
DVB	B-Application
digital	B-Application
television	I-Application
contains	O
audio/visual	O
signals	O
that	O
are	O
broadcast	B-Operating_System
over	O
the	O
air	O
in	O
a	O
digital	B-General_Concept
rather	O
than	O
analog	O
format	O
.	O
</s>
<s>
The	O
DVB	B-Application
data	O
stream	O
can	O
be	O
directly	O
recorded	O
by	O
the	O
DVR	O
.	O
</s>
<s>
Devices	O
that	O
can	O
use	O
external	O
storage	O
devices	O
(	O
such	O
as	O
hard	B-Device
disks	I-Device
,	O
SSDs	B-Device
,	O
or	O
other	O
flash	B-Device
storage	I-Device
)	O
to	O
store	O
and	O
recover	O
data	O
without	O
the	O
aid	O
of	O
another	O
device	O
are	O
sometimes	O
called	O
telememory	O
devices	O
.	O
</s>
<s>
Recording	O
satellite	O
television	O
or	O
digital	B-Device
cable	I-Device
signals	O
on	O
a	O
digital	B-Application
video	I-Application
recorder	I-Application
can	O
be	O
more	O
complex	O
than	O
recording	O
analog	O
signals	O
or	O
broadcast	B-Operating_System
digital	B-General_Concept
signals	O
.	O
</s>
<s>
In	O
order	O
to	O
record	O
cable	O
or	O
satellite	O
digital	B-General_Concept
signals	O
the	O
signal	O
must	O
be	O
captured	O
after	O
it	O
has	O
been	O
decrypted	O
but	O
before	O
it	O
is	O
decoded	O
;	O
this	O
is	O
how	O
DVRs	O
built	O
into	O
set-top	O
boxes	O
work	O
.	O
</s>
<s>
Cable	O
and	O
satellite	O
providers	O
often	O
offer	O
their	O
own	O
digital	B-Application
video	I-Application
recorders	I-Application
along	O
with	O
a	O
service	O
plan	O
.	O
</s>
<s>
In	O
the	O
United	O
States	O
,	O
this	O
is	O
prohibited	O
under	O
the	O
Digital	B-General_Concept
Millennium	O
Copyright	O
Act	O
if	O
the	O
disc	O
is	O
encrypted	O
.	O
</s>
<s>
A	O
digital	B-General_Concept
camcorder	O
combines	O
a	O
camera	O
and	O
a	O
digital	B-Application
video	I-Application
recorder	I-Application
.	O
</s>
<s>
Some	O
DVD-based	O
DVRs	O
incorporate	O
connectors	O
that	O
can	O
be	O
used	O
to	O
capture	O
digital	B-General_Concept
video	O
from	O
a	O
camcorder	O
.	O
</s>
<s>
Some	O
digital	B-Application
video	I-Application
recorders	I-Application
can	O
now	O
record	O
to	O
solid	O
state	O
flash	B-Device
memory	I-Device
cards	I-Device
(	O
called	O
flash	O
camcorders	O
)	O
.	O
</s>
<s>
They	O
generally	O
use	O
Secure	B-Device
Digital	I-Device
cards	I-Device
,	O
can	O
include	O
wireless	O
connections	O
(	O
Bluetooth	B-Protocol
and	O
Wi-Fi	O
)	O
,	O
and	O
can	O
play	O
SWF	O
files	O
.	O
</s>
<s>
There	O
are	O
some	O
digital	B-Application
video	I-Application
recorders	I-Application
that	O
combine	O
video	O
and	O
graphics	O
in	O
real	O
time	O
to	O
the	O
flash	O
card	O
,	O
called	O
DTE	B-Device
or	O
"	O
direct	O
to	O
edit	O
"	O
.	O
</s>
<s>
DVRs	O
can	O
usually	O
record	O
and	O
play	O
H.264	B-Application
,	O
MPEG-4	B-Application
Part	I-Application
2	I-Application
,	O
MPEG-2	B-Algorithm
.mpg	O
,	O
MPEG-2	B-Algorithm
.TS	O
,	O
VOB	O
and	O
ISO	B-General_Concept
images	I-General_Concept
video	O
,	O
with	O
MP3	B-Application
and	O
AC3	O
audio	O
tracks	O
.	O
</s>
<s>
They	O
can	O
also	O
display	O
images	O
(	O
JPEG	O
and	O
PNG	O
)	O
and	O
play	O
music	O
files	O
(	O
MP3	B-Application
and	O
Ogg	O
)	O
.	O
</s>
<s>
Some	O
devices	O
can	O
be	O
updated	B-Application
to	O
play	O
and	O
record	O
in	O
new	O
formats	O
.	O
</s>
<s>
DVRs	O
usually	O
record	O
in	O
proprietary	B-Application
file	B-Application
systems	I-Application
for	O
copy	B-Application
protection	I-Application
,	O
although	O
some	O
can	O
use	O
FAT	B-Application
file	I-Application
systems	I-Application
.	O
</s>
<s>
Recordings	O
from	O
standard-definition	B-Device
television	I-Device
usually	O
have	O
480p/i/576p/i	O
while	O
HDTV	B-Device
is	O
usually	O
in	O
720p/1080i	O
.	O
</s>
<s>
Digital	B-Application
video	I-Application
recorders	I-Application
configured	O
for	O
physical	O
security	O
applications	O
record	O
video	O
signals	O
from	O
closed-circuit	O
television	O
cameras	O
for	O
detection	O
and	O
documentation	O
purposes	O
.	O
</s>
<s>
There	O
is	O
also	O
much	O
more	O
control	O
over	O
quality	O
and	O
frame	O
rate	O
allowing	O
disk	B-Device
space	O
usage	O
to	O
be	O
optimized	O
and	O
the	O
DVR	O
can	O
also	O
be	O
set	O
to	O
overwrite	O
the	O
oldest	O
security	O
footage	O
should	O
the	O
disk	B-Device
become	O
full	O
.	O
</s>
<s>
Some	O
of	O
the	O
latest	O
professional	O
digital	B-Application
video	I-Application
recorders	I-Application
include	O
video	O
analytics	O
firmware	B-Application
,	O
to	O
enable	O
functionality	O
such	O
as	O
'	O
virtual	O
tripwire	O
 '	O
or	O
even	O
the	O
detection	O
of	O
abandoned	O
objects	O
on	O
the	O
scene	O
.	O
</s>
<s>
Security	O
DVRs	O
may	O
be	O
categorized	O
as	O
being	O
either	O
PC-based	O
or	O
embedded	B-Architecture
.	O
</s>
<s>
A	O
PC-based	O
DVR	O
's	O
architecture	O
is	O
a	O
classical	O
personal	B-Device
computer	I-Device
with	O
video	B-General_Concept
capture	I-General_Concept
cards	O
designed	O
to	O
capture	B-General_Concept
video	I-General_Concept
images	O
.	O
</s>
<s>
An	O
embedded	B-Architecture
type	O
DVR	O
is	O
specifically	O
designed	O
as	O
a	O
digital	B-Application
video	I-Application
recorder	I-Application
with	O
its	O
operating	B-General_Concept
system	I-General_Concept
and	O
application	B-Application
software	I-Application
contained	O
in	O
firmware	B-Application
or	O
read-only	B-Device
memory	I-Device
.	O
</s>
<s>
Hardware	B-Architecture
features	O
of	O
security	O
DVRs	O
vary	O
between	O
manufacturers	O
and	O
may	O
include	O
but	O
are	O
not	O
necessarily	O
limited	O
to	O
:	O
</s>
<s>
Designed	O
for	O
rack	B-Application
mounting	O
or	O
desktop	O
configurations	O
.	O
</s>
<s>
Single	O
or	O
multiple	O
video	O
inputs	O
with	O
connector	O
types	O
consistent	O
with	O
the	O
analogue	O
or	O
digital	B-General_Concept
video	O
provided	O
such	O
as	O
coaxial	O
cable	O
,	O
twisted	O
pair	O
or	O
optical	O
fiber	O
cable	O
.	O
</s>
<s>
Systems	O
may	O
be	O
configured	O
with	O
a	O
very	O
large	O
number	O
of	O
inputs	O
by	O
networking	O
or	O
bussing	B-General_Concept
individual	O
DVRs	O
together	O
.	O
</s>
<s>
These	O
output	O
signals	O
are	O
used	O
by	O
other	O
video	O
equipment	O
such	O
as	O
matrix	O
switchers	O
,	O
multiplexers	B-Protocol
,	O
and	O
video	O
monitors	O
.	O
</s>
<s>
Connections	O
to	O
external	O
control	O
devices	O
such	O
as	O
keyboards	B-Device
.	O
</s>
<s>
Connections	O
to	O
external	O
storage	B-General_Concept
media	I-General_Concept
.	O
</s>
<s>
Selectable	O
image	B-Algorithm
resolution	I-Algorithm
either	O
on	O
an	O
all	O
input	O
basis	O
or	O
input	O
by	O
input	O
basis	O
.	O
</s>
<s>
The	O
image	B-Algorithm
resolution	I-Algorithm
feature	O
may	O
be	O
programmed	O
to	O
automatically	O
adjust	O
the	O
image	B-Algorithm
resolution	I-Algorithm
on	O
the	O
occurrence	O
of	O
an	O
external	O
alarm	O
or	O
an	O
internal	O
event	O
.	O
</s>
<s>
H.264	B-Application
hardware	B-Architecture
compression	O
offers	O
fast	O
transfer	O
rates	O
over	O
the	O
Internet	O
with	O
high	O
quality	O
video	O
.	O
</s>
<s>
Detection	O
causes	O
an	O
internal	O
event	O
that	O
may	O
be	O
output	O
to	O
external	O
equipment	O
and/or	O
be	O
used	O
to	O
trigger	B-Application
changes	O
in	O
other	O
internal	O
features	O
.	O
</s>
<s>
Detection	O
causes	O
an	O
internal	O
event	O
that	O
may	O
be	O
output	O
to	O
external	O
equipment	O
and/or	O
used	O
to	O
trigger	B-Application
changes	O
in	O
other	O
internal	O
features	O
.	O
</s>
<s>
Detection	O
causes	O
an	O
internal	O
event	O
that	O
may	O
be	O
output	O
to	O
external	O
equipment	O
and/or	O
be	O
used	O
to	O
trigger	B-Application
changes	O
in	O
other	O
internal	O
features	O
.	O
</s>
<s>
Some	O
(	O
very	O
few	O
)	O
,	O
but	O
certainly	O
not	O
all	O
,	O
digital	B-Application
video	I-Application
recorders	I-Application
which	O
are	O
designed	O
to	O
send	O
information	O
to	O
a	O
service	O
provider	O
over	O
a	O
telephone	O
line	O
or	O
Internet	O
(	O
or	O
any	O
other	O
way	O
)	O
can	O
gather	O
and	O
send	O
real-time	O
data	O
on	O
users	O
 '	O
viewing	O
habits	O
.	O
</s>
<s>
This	O
problem	O
was	O
noted	O
back	O
in	O
2000	O
and	O
was	O
still	O
considered	O
a	O
problem	O
,	O
specifically	O
with	O
TiVo	B-Application
,	O
in	O
2015	O
.	O
</s>
<s>
Digital	B-Application
video	I-Application
recorders	I-Application
are	O
also	O
changing	O
the	O
way	O
television	O
programs	O
advertise	O
products	O
.	O
</s>
<s>
In	O
1985	O
,	O
an	O
employee	O
of	O
Honeywell	O
's	O
Physical	O
Sciences	O
Center	O
,	O
David	O
Rafner	O
,	O
first	O
described	O
a	O
drive-based	O
DVR	O
designed	O
for	O
home	O
TV	O
recording	O
,	O
time	B-Device
shifting	I-Device
,	O
and	O
commercial	B-Application
skipping	O
.	O
</s>
<s>
The	O
first	O
DVR	O
which	O
had	O
a	O
built-in	O
commercial	B-Application
skipping	O
feature	O
introduced	O
in	O
1999	O
by	O
ReplayTV	B-Device
at	O
the	O
Consumer	O
Electronics	O
Show	O
in	O
Las	O
Vegas	O
.	O
</s>
<s>
In	O
2002	O
,	O
five	O
owners	O
of	O
the	O
ReplayTV	B-Device
DVR	O
sued	O
the	O
main	O
television	O
networks	O
and	O
movie	O
studios	O
,	O
asking	O
the	O
federal	O
judge	O
to	O
uphold	O
consumers	O
 '	O
rights	O
to	O
record	O
TV	O
shows	O
and	O
skip	O
commercials	O
,	O
claiming	O
that	O
features	O
such	O
as	O
commercial	B-Application
skipping	O
help	O
parents	O
protect	O
their	O
kids	O
from	O
excessive	O
consumerism	O
.	O
</s>
<s>
ReplayTV	B-Device
was	O
purchased	O
by	O
SONICblue	O
in	O
2001	O
and	O
in	O
March	O
2003	O
,	O
SONICblue	O
filed	O
for	O
Chapter	O
11	O
bankruptcy	O
after	O
fighting	O
a	O
copyright	O
infringement	O
suit	O
over	O
the	O
ReplayTV	B-Device
's	O
ability	O
to	O
skip	O
commercials	O
.	O
</s>
<s>
In	O
2007	O
,	O
DirecTV	O
purchased	O
the	O
remaining	O
assets	O
of	O
ReplayTV	B-Device
.	O
</s>
<s>
A	O
third-party	B-General_Concept
add-on	O
for	O
Windows	B-Device
Media	I-Device
Center	I-Device
called	O
"	O
DVRMSToolbox	O
"	O
has	O
the	O
ability	O
to	O
skip	O
commercials	O
.	O
</s>
<s>
There	O
is	O
a	O
command-line	O
program	O
called	O
Comskip	O
that	O
detects	O
commercials	O
in	O
an	O
MPEG-2	B-Algorithm
file	O
and	O
saves	O
their	O
positions	O
to	O
a	O
text	O
file	O
.	O
</s>
<s>
This	O
file	O
can	O
then	O
be	O
fed	O
to	O
a	O
program	O
like	O
MEncoder	B-Language
to	O
actually	O
remove	O
the	O
commercials	O
.	O
</s>
<s>
With	O
ad	O
skipping	O
and	O
the	O
time-sensitive	O
nature	O
of	O
certain	O
ads	O
,	O
advertisers	O
are	O
wary	O
of	O
buying	O
commercial	B-Application
time	O
on	O
shows	O
that	O
are	O
heavily	O
digitally	O
video-recorded	O
.	O
</s>
<s>
DirecTV	O
in	O
March	O
2011	O
signed	O
an	O
arrangement	O
with	O
NDS	B-Device
Group	I-Device
to	O
enable	O
the	O
delivery	O
of	O
such	O
addressable	O
advertisement	O
.	O
</s>
<s>
In	O
January	O
2012	O
,	O
Dish	O
Network	O
announced	O
Hopper	B-Device
service	O
,	O
costing	O
$10	O
extra	O
per	O
month	O
,	O
which	O
recorded	O
prime-time	O
programming	O
from	O
the	O
four	O
major	O
broadcast	B-Operating_System
networks	O
.	O
</s>
<s>
On	O
March	O
23	O
,	O
2007	O
,	O
Cablevision	O
Systems	O
Corp	O
lost	O
a	O
legal	O
battle	O
against	O
several	O
Hollywood	O
studios	O
and	O
television	O
networks	O
to	O
introduce	O
a	O
network-based	O
digital	B-Application
video	I-Application
recorder	I-Application
service	O
to	O
its	O
subscribers	O
.	O
</s>
<s>
In	O
court	O
,	O
the	O
media	O
companies	O
argued	O
that	O
network	O
digital	B-Application
video	I-Application
recorders	I-Application
were	O
tantamount	O
to	O
video-on-demand	O
,	O
and	O
that	O
they	O
should	O
receive	O
license	O
fees	O
for	O
the	O
recording	O
.	O
</s>
<s>
In	O
2004	O
,	O
TiVo	B-Application
sued	O
EchoStar	O
Corp	O
,	O
a	O
manufacturer	O
of	O
DVR	O
units	O
,	O
for	O
patent	O
infringement	O
.	O
</s>
<s>
The	O
parties	O
reached	O
a	O
settlement	O
in	O
2011	O
wherein	O
EchoStar	O
pays	O
a	O
one-time	O
fee	O
(	O
in	O
three	O
structured	O
payments	O
)	O
that	O
grants	O
Echostar	O
full	O
rights	O
for	O
life	O
to	O
the	O
disputed	O
TiVo	B-Application
patents	O
upon	O
first	O
payment(as opposed to indefinite and escalating license fees to be constantly renegotiated )	O
,	O
and	O
Echostar	O
granted	O
TiVo	B-Application
full	O
rights	O
for	O
life	O
to	O
certain	O
Echostar	O
patents	O
and	O
dropped	O
their	O
counter-suit	O
against	O
TiVo	B-Application
.	O
</s>
<s>
In	O
January	O
2012	O
,	O
AT&T	O
settled	O
a	O
similar	O
suit	O
brought	O
by	O
TiVo	B-Application
claiming	O
patent	O
infringement	O
(	O
just	O
as	O
with	O
Echostar	O
)	O
in	O
exchange	O
for	O
cash	O
payments	O
to	O
TiVo	B-Application
totaling	O
$215	O
million	O
through	O
June	O
2018	O
plus	O
"	O
incremental	O
recurring	O
per	O
subscriber	O
monthly	O
license	O
fees	O
"	O
to	O
TiVo	B-Application
through	O
July	O
2018	O
,	O
but	O
grants	O
no	O
full	O
lifetime	O
rights	O
as	O
per	O
the	O
Echostar	O
settlement	O
.	O
</s>
<s>
In	O
May	O
2012	O
,	O
Fox	O
Broadcasting	B-Operating_System
sued	O
Dish	O
Network	O
,	O
arguing	O
that	O
Dish	O
's	O
set-top	O
box	O
with	O
DVR	O
function	O
,	O
which	O
allowed	O
the	O
users	O
to	O
automatically	O
record	O
prime-time	O
programs	O
and	O
skip	O
commercials	O
,	O
was	O
copyright	O
infringement	O
and	O
breach	O
of	O
contract	O
.	O
</s>
