<s>
SMPTE	B-Operating_System
421	I-Operating_System
,	O
informally	O
known	O
as	O
VC-1	B-Operating_System
,	O
is	O
a	O
video	B-Algorithm
coding	I-Algorithm
format	I-Algorithm
.	O
</s>
<s>
Most	O
of	O
it	O
was	O
initially	O
developed	O
as	O
Microsoft	O
's	O
proprietary	O
video	O
format	O
Windows	B-Device
Media	I-Device
Video	I-Device
9	I-Device
in	O
2003	O
.	O
</s>
<s>
It	O
was	O
primarily	O
marketed	O
as	O
a	O
lower-complexity	O
competitor	O
to	O
the	O
H.264/MPEG	B-Application
-4	I-Application
AVC	I-Application
standard	O
.	O
</s>
<s>
VC-1	B-Operating_System
is	O
supported	O
in	O
the	O
now-deprecated	O
Microsoft	B-Application
Silverlight	I-Application
,	O
the	O
briefly-offered	O
HD	B-Operating_System
DVD	I-Operating_System
disc	O
format	O
,	O
and	O
the	O
Blu-ray	O
Disc	O
format	O
.	O
</s>
<s>
VC-1	B-Operating_System
is	O
an	O
evolution	O
of	O
the	O
conventional	O
block-based	O
motion-compensated	B-Algorithm
hybrid	O
video	B-Algorithm
coding	I-Algorithm
design	O
also	O
found	O
in	O
H.261	B-Algorithm
,	O
MPEG-1	O
Part	O
2	O
,	O
H.262/MPEG	B-Algorithm
-2	I-Algorithm
Part	I-Algorithm
2	I-Algorithm
,	O
H.263	B-Algorithm
,	O
and	O
MPEG-4	B-Application
Part	I-Application
2	I-Application
.	O
</s>
<s>
It	O
was	O
widely	O
characterized	O
as	O
an	O
alternative	O
to	O
the	O
ITU-T	O
and	O
MPEG	O
video	O
codec	O
standard	O
known	O
as	O
H.264/MPEG	B-Application
-4	I-Application
AVC	I-Application
.	O
</s>
<s>
The	O
Advanced	O
Profile	O
of	O
VC-1	B-Operating_System
contains	O
tools	O
designed	O
for	O
coding	O
interlaced	O
video	O
sequences	O
as	O
well	O
as	O
progressive	B-Device
scan	I-Device
video	O
.	O
</s>
<s>
The	O
main	O
goal	O
of	O
the	O
development	O
and	O
standardization	O
of	O
the	O
VC-1	B-Operating_System
Advanced	O
Profile	O
was	O
to	O
support	O
interlace-optimized	O
compression	O
of	O
interlaced	O
content	O
without	O
first	O
converting	O
it	O
to	O
progressive	B-Device
scan	I-Device
,	O
making	O
it	O
more	O
attractive	O
to	O
broadcast	O
and	O
video	O
industry	O
professionals	O
using	O
the	O
1080i	O
format	O
.	O
</s>
<s>
Both	O
HD	B-Operating_System
DVD	I-Operating_System
and	O
Blu-ray	O
Disc	O
adopted	O
VC-1	B-Operating_System
as	O
a	O
supported	O
video	O
format	O
,	O
meaning	O
their	O
video	O
playback	O
devices	O
are	O
required	O
to	O
be	O
capable	O
of	O
decoding	O
and	O
playing	O
video-content	O
compressed	O
using	O
VC-1	B-Operating_System
.	O
</s>
<s>
Windows	B-Application
Vista	I-Application
partially	O
supports	O
HD	B-Operating_System
DVD	I-Operating_System
playback	O
by	O
including	O
the	O
VC-1	B-Operating_System
decoder	O
and	O
some	O
related	O
components	O
needed	O
for	O
playback	O
of	O
VC-1	B-Operating_System
encoded	O
HD	B-Operating_System
DVD	I-Operating_System
movies	O
.	O
</s>
<s>
Microsoft	O
designated	O
VC-1	B-Operating_System
as	O
the	B-Operating_System
Xbox	I-Operating_System
360	I-Operating_System
video	B-Device
game	I-Device
console	I-Device
's	O
official	O
video	O
format	O
,	O
and	O
game	O
developers	O
could	O
use	O
VC-1	B-Operating_System
for	O
full	B-Application
motion	I-Application
video	I-Application
included	O
with	O
games	O
.	O
</s>
<s>
By	O
means	O
of	O
an	O
October	O
31	O
,	O
2006	O
update	O
,	O
all	O
formats	O
of	O
Windows	B-Application
Media	I-Application
Video	I-Application
could	O
be	O
played	O
on	O
the	B-Operating_System
Xbox	I-Operating_System
360	I-Operating_System
from	O
a	O
disc	O
,	O
USB	O
storage	O
device	O
,	O
or	O
streaming	O
from	O
a	O
PC	O
via	O
Windows	O
Media	O
Connect/Windows	O
Media	O
Player	O
11	O
.	O
</s>
<s>
VC-1	B-Operating_System
is	O
supported	O
in	O
the	O
PlayStation	B-Operating_System
3	I-Operating_System
console	O
and	O
the	O
FFmpeg	B-Library
project	O
also	O
includes	O
a	O
VC-1	B-Operating_System
decoder	O
.	O
</s>
<s>
On	O
August	O
24	O
,	O
2012	O
,	O
the	O
Raspberry	B-Operating_System
Pi	I-Operating_System
Foundation	O
announced	O
hardware	O
decoding	O
support	O
for	O
VC-1	B-Operating_System
.	O
</s>
<s>
The	O
VC-1	B-Operating_System
codec	O
specification	O
has	O
so	O
far	O
been	O
implemented	O
by	O
Microsoft	O
in	O
the	O
form	O
of	O
three	O
codecs	O
,	O
each	O
identified	O
with	O
a	O
unique	O
four	B-Application
character	I-Application
code	I-Application
.	O
</s>
<s>
The	O
Simple	O
and	O
Main	O
Profiles	O
of	O
VC-1	B-Operating_System
remained	O
completely	O
faithful	O
to	O
the	O
existing	O
WMV3	B-Device
implementation	O
,	O
making	O
WMV3	B-Device
bitstreams	O
fully	O
VC-1	B-Operating_System
compliant	O
.	O
</s>
<s>
The	O
WMV3	B-Device
codec	O
was	O
designed	O
to	O
primarily	O
support	O
progressive	O
encoding	O
for	O
computer	O
displays	O
.	O
</s>
<s>
An	O
interlaced	O
encoding	O
mode	O
was	O
implemented	O
,	O
but	O
quickly	O
became	O
deprecated	O
when	O
Microsoft	O
started	O
implementing	O
WMV	B-Device
Advanced	O
Profile	O
.	O
</s>
<s>
Whereas	O
WMV3	B-Device
progressive	O
encoding	O
was	O
implemented	O
using	O
the	O
YUV	O
4:2:0	O
color	O
sampling	O
scheme	O
,	O
the	O
deprecated	O
interlaced	O
mode	O
was	O
implemented	O
using	O
the	O
less	O
common	O
YUV	O
4:1:1	O
sampling	O
scheme	O
.	O
</s>
<s>
The	O
Windows	B-Device
Media	I-Device
Video	I-Device
9	I-Device
(	O
WMV3	B-Device
)	O
codec	O
implements	O
the	O
Simple	O
and	O
Main	O
modes	O
of	O
the	O
VC-1	B-Operating_System
codec	O
standard	O
,	O
providing	O
high-quality	O
video	O
for	O
streaming	O
and	O
downloading	O
.	O
</s>
<s>
A	O
number	O
of	O
high	O
definition	O
movies	O
and	O
videos	O
have	O
been	O
released	O
commercially	O
in	O
a	O
format	O
dubbed	O
WMV	B-Device
HD	B-Device
.	O
</s>
<s>
These	O
titles	O
are	O
encoded	O
with	O
WMV3	B-Device
Main	O
Profile	O
@	O
High	O
Level	O
(	O
MP	O
@HL	O
)	O
.	O
</s>
<s>
WMVA	O
was	O
the	O
original	O
implementation	O
of	O
WMV	B-Device
Advanced	O
Profile	O
prior	O
to	O
the	O
acceptance	O
of	O
the	O
VC-1	B-Operating_System
draft	O
by	O
SMPTE	O
.	O
</s>
<s>
The	O
codec	O
was	O
distributed	O
with	O
Windows	B-Device
Media	I-Device
Player	I-Device
10	I-Device
and	O
Windows	O
Media	O
Format	O
SDK	O
9.5	O
install	O
packages	O
.	O
</s>
<s>
There	O
are	O
slight	O
bitstream	O
differences	O
between	O
WMVA	O
and	O
WVC1	B-Operating_System
,	O
so	O
consequently	O
WMVA	O
is	O
handled	O
by	O
a	O
different	O
DirectShow	B-Library
decoder	O
than	O
WVC1	B-Operating_System
.	O
</s>
<s>
As	O
of	O
2006	O
,	O
WMVA	O
is	O
considered	O
a	O
deprecated	O
codec	O
because	O
it	O
is	O
not	O
fully	O
VC-1	B-Operating_System
compliant	O
.	O
</s>
<s>
WVC1	B-Operating_System
,	O
also	O
known	O
as	O
Windows	B-Device
Media	I-Device
Video	I-Device
9	I-Device
Advanced	O
Profile	O
,	O
implements	O
a	O
more	O
recent	O
and	O
fully	O
compliant	O
Advanced	O
Profile	O
of	O
the	O
VC-1	B-Operating_System
codec	O
standard	O
.	O
</s>
<s>
With	O
the	O
previous	O
version	O
of	O
the	O
Windows	B-Device
Media	I-Device
Video	I-Device
9	I-Device
Series	O
codec	O
,	O
users	O
could	O
deliver	O
progressive	O
content	O
at	O
data	O
rates	O
as	O
low	O
as	O
one-third	O
that	O
of	O
the	O
MPEG-2	O
codec	O
and	O
still	O
get	O
equivalent	O
or	O
comparable	O
quality	O
to	O
MPEG-2	O
.	O
</s>
<s>
The	O
Windows	B-Device
Media	I-Device
Video	I-Device
9	I-Device
Advanced	O
Profile	O
codec	O
also	O
offers	O
this	O
same	O
improvement	O
in	O
encoding	O
efficiency	O
with	O
interlaced	O
contents	O
.	O
</s>
<s>
A	O
decoder	O
for	O
WVC1	B-Operating_System
is	O
included	O
in	O
Windows	B-Device
Media	I-Device
Player	I-Device
11	I-Device
,	O
which	O
is	O
bundled	O
with	O
Windows	B-Application
Vista	I-Application
and	O
is	O
available	O
as	O
a	O
download	O
for	O
Windows	O
XP	O
.	O
</s>
<s>
This	O
implementation	O
is	O
supported	O
in	O
Microsoft	B-Application
Silverlight	I-Application
.	O
</s>
<s>
Due	O
to	O
its	O
origins	O
in	O
Microsoft	O
's	O
WMV9	B-Device
codec	O
,	O
the	O
most	O
popular	O
implementations	O
of	O
VC-1	B-Operating_System
encoders	O
have	O
so	O
far	O
been	O
done	O
by	O
Microsoft	O
,	O
though	O
third-party	O
implementations	O
exist	O
as	O
well	O
.	O
</s>
<s>
Sonic	O
Cinevision	O
PSE	O
,	O
a	O
professional	O
VC-1	B-Operating_System
encoding	O
tool	O
used	O
predominantly	O
in	O
HD	B-Operating_System
DVD	I-Operating_System
and	O
Blu-ray	O
encoding	O
,	O
is	O
a	O
commercial	O
version	O
of	O
Microsoft	O
's	O
PEP	O
(	O
Parallel	O
Encoder	O
)	O
encoding	O
tool	O
and	O
VC-1	B-Operating_System
Analyzer	O
tool	O
.	O
</s>
<s>
Microsoft	O
also	O
provides	O
a	O
separate	O
VC-1	B-Operating_System
Encoder	O
SDK	O
which	O
allows	O
any	O
company	O
or	O
software	O
developer	O
to	O
integrate	O
VC-1	B-Operating_System
encoding	O
into	O
their	O
applications	O
.	O
</s>
<s>
Non-Microsoft	O
VC-1	B-Operating_System
implementations	O
(	O
based	O
entirely	O
on	O
the	O
SMPTE	O
specifications	O
)	O
have	O
been	O
done	O
by	O
Ericsson	O
Television	O
and	O
MainConcept	B-Algorithm
.	O
</s>
<s>
The	O
FFmpeg	B-Library
project	O
includes	O
a	O
free	B-Application
VC-1	B-Operating_System
decoder	O
.	O
</s>
<s>
Windows	B-Protocol
Media	I-Protocol
Encoder	I-Protocol
9	O
Series	O
encodes	O
VC-1	B-Operating_System
compliant	O
video	O
files	O
,	O
including	O
WVC1	B-Operating_System
FourCC	B-Application
media	O
.	O
</s>
<s>
Windows	O
Media	O
Format	O
11	O
Runtime	O
or	O
Windows	B-Device
Media	I-Device
Player	I-Device
11	I-Device
must	O
be	O
installed	O
on	O
the	O
computer	O
to	O
ensure	O
full	O
VC-1	B-Operating_System
compliance	O
across	O
all	O
three	O
profiles	O
(	O
Simple	O
,	O
Main	O
and	O
Advanced	O
)	O
.	O
</s>
<s>
If	O
either	O
of	O
these	O
are	O
installed	O
,	O
Windows	B-Application
Movie	I-Application
Maker	I-Application
can	O
also	O
save	O
VC-1	B-Operating_System
compliant	O
videos	O
,	O
as	O
can	O
any	O
other	O
application	O
built	O
on	O
the	O
Windows	O
Media	O
Format	O
SDK	O
or	O
Windows	O
Media	O
Codec	O
DMOs	O
.	O
</s>
<s>
A	O
Windows	B-Protocol
Media	I-Protocol
Encoder	I-Protocol
Studio	O
Edition	O
was	O
initially	O
announced	O
for	O
professional	O
encoding	O
but	O
later	O
cancelled	O
by	O
Microsoft	O
.	O
</s>
<s>
Microsoft	B-Application
Expression	I-Application
Encoder	I-Application
which	O
is	O
part	O
of	O
Expression	B-Application
Studio	I-Application
supports	O
encoding	O
VC-1	B-Operating_System
video	O
to	O
the	O
Windows	O
Media	O
(	O
ASF	B-Application
)	O
file	O
format	O
and	O
the	O
IIS	O
Smooth	O
Streaming	O
format	O
.	O
</s>
<s>
Video	O
encoder	O
products	O
made	O
by	O
Inlet	O
,	O
Digital	O
Rapids	O
,	O
Harmonic	O
,	O
Envivio	O
,	O
Elemental	O
Technologies	O
,	O
Anystream	O
,	O
Telestream	O
and	O
Rhozet	O
support	O
VC-1	B-Operating_System
encoding	O
(	O
based	O
on	O
the	O
Microsoft	O
VC-1	B-Operating_System
Encoder	O
SDK	O
)	O
for	O
IPTV	O
and	O
Web	O
streaming	O
.	O
</s>
<s>
Because	O
VC-1	B-Operating_System
encoding	O
and	O
decoding	O
requires	O
significant	O
computing	O
power	O
,	O
software	O
implementation	O
that	O
run	O
on	O
a	O
general-purpose	O
CPU	O
are	O
typically	O
slow	O
,	O
especially	O
when	O
dealing	O
with	O
HD	B-Device
video	O
content	O
.	O
</s>
<s>
A	O
hardware	O
VC-1	B-Operating_System
encoder	O
can	O
be	O
an	O
ASIC	O
or	O
an	O
FPGA	B-Architecture
.	O
</s>
<s>
Hardware-accelerated	O
(	O
also	O
known	O
as	O
hardware-assisted	O
)	O
video	O
decoding	O
can	O
either	O
be	O
done	O
on	O
dedicated	O
,	O
special-purpose	O
hardware	O
or	O
on	O
generic	O
,	O
multi-purpose	O
hardware	O
such	O
as	O
GPUs	B-Architecture
.	O
</s>
<s>
Nearly	O
all	O
video	O
cards	O
manufactured	O
since	O
2006	O
support	O
some	O
level	O
of	O
GPU-accelerated	O
VC-1	B-Operating_System
decoding	O
on	O
the	O
Windows	O
platform	O
via	O
DirectX	B-General_Concept
Video	I-General_Concept
Acceleration	I-General_Concept
APIs	O
.	O
</s>
<s>
The	O
native	O
Windows	O
WMV9/VC	O
-1	O
decoder	O
(	O
wmvdecod.dll	O
)	O
only	O
supports	O
DXVA	B-General_Concept
profiles	O
A	O
,	O
B	O
and	O
C	O
,	O
while	O
3rd	O
party	O
VC-1	B-Operating_System
decoders	O
such	O
as	O
CyberLink	O
's	O
support	O
the	O
full	O
DXVA	B-General_Concept
Profile	O
D	O
decode	O
acceleration	O
.	O
</s>
<s>
There	O
is	O
no	O
support	O
for	O
GPU-accelerated	O
VC-1	B-Operating_System
decode	O
on	O
the	O
MacOS	O
platform	O
.	O
</s>
<s>
Raspberry	B-Operating_System
Pi	I-Operating_System
hardware	O
prior	O
to	O
Raspberry	B-Operating_System
Pi	I-Operating_System
4	O
supports	O
VC-1	B-Operating_System
hardware-accelerated	O
decoding	O
,	O
although	O
it	O
requires	O
purchasing	O
of	O
a	O
license	O
key	O
.	O
</s>
<s>
Although	O
heavily	O
associated	O
with	O
Microsoft	O
,	O
there	O
are	O
18	O
member	O
companies	O
within	O
the	O
VC-1	B-Operating_System
patent	O
pool	O
.	O
</s>
<s>
As	O
an	O
SMPTE	O
standard	O
,	O
VC-1	B-Operating_System
is	O
open	O
to	O
implementation	O
by	O
anyone	O
,	O
although	O
implementers	O
may	O
be	O
required	O
to	O
pay	O
licensing	O
fees	O
to	O
the	O
MPEG	O
LA	O
,	O
the	O
LLC	O
licensing	O
body	O
or	O
directly	O
to	O
its	O
members	O
,	O
who	O
claim	O
to	O
hold	O
essential	O
patents	O
on	O
the	O
format	O
(	O
since	O
it	O
is	O
a	O
non-exclusive	O
licensing	O
body	O
)	O
.	O
</s>
<s>
The	O
following	O
organizations	O
hold	O
one	O
or	O
more	O
patents	O
in	O
the	O
VC-1	B-Operating_System
patent	O
pool	O
,	O
as	O
listed	O
by	O
MPEG	O
LA	O
.	O
</s>
