<s>
Windows	B-Application
Media	I-Application
Video	I-Application
(	O
WMV	B-Device
)	O
is	O
a	O
series	O
of	O
video	B-Application
codecs	I-Application
and	O
their	O
corresponding	O
video	B-Algorithm
coding	I-Algorithm
formats	I-Algorithm
developed	O
by	O
Microsoft	O
.	O
</s>
<s>
It	O
is	O
part	O
of	O
the	O
Windows	B-Device
Media	I-Device
framework	O
.	O
</s>
<s>
WMV	B-Device
consists	O
of	O
three	O
distinct	O
codecs	O
:	O
The	O
original	O
video	O
compression	O
technology	O
known	O
as	O
WMV	B-Device
,	O
was	O
originally	O
designed	O
for	O
Internet	O
streaming	O
applications	O
,	O
as	O
a	O
competitor	O
to	O
RealVideo	B-Algorithm
.	O
</s>
<s>
The	O
other	O
compression	O
technologies	O
,	O
WMV	B-Device
Screen	O
and	O
WMV	B-Device
Image	O
,	O
cater	O
for	O
specialized	O
content	O
.	O
</s>
<s>
After	O
standardization	O
by	O
the	O
Society	O
of	O
Motion	O
Picture	O
and	O
Television	O
Engineers	O
(	O
SMPTE	O
)	O
,	O
WMV	B-Device
version	O
9	O
was	O
adapted	O
for	O
physical-delivery	O
formats	O
such	O
as	O
HD	B-Operating_System
DVD	I-Operating_System
and	O
Blu-ray	O
Disc	O
and	O
became	O
known	O
as	O
VC-1	B-Operating_System
.	O
</s>
<s>
Microsoft	O
also	O
developed	O
a	O
digital	O
container	O
format	O
called	O
Advanced	B-Application
Systems	I-Application
Format	I-Application
to	O
store	O
video	O
encoded	O
by	O
Windows	B-Application
Media	I-Application
Video	I-Application
.	O
</s>
<s>
In	O
2003	O
,	O
Microsoft	O
drafted	O
a	O
video	B-Algorithm
compression	I-Algorithm
specification	I-Algorithm
based	O
on	O
its	O
WMV	B-Device
9	O
format	O
and	O
submitted	O
it	O
to	O
SMPTE	O
for	O
standardization	O
.	O
</s>
<s>
The	O
standard	O
was	O
officially	O
approved	O
in	O
March	O
2006	O
as	O
SMPTE	B-Operating_System
421M	I-Operating_System
,	O
better	O
known	O
as	O
VC-1	B-Operating_System
,	O
thus	O
making	O
the	O
WMV	B-Device
9	O
format	O
an	O
open	O
standard	O
.	O
</s>
<s>
VC-1	B-Operating_System
became	O
one	O
of	O
the	O
three	O
video	O
formats	O
for	O
the	O
Blu-ray	O
video	O
disc	O
,	O
along	O
with	O
H.262/MPEG	B-Algorithm
-2	I-Algorithm
Part	I-Algorithm
2	I-Algorithm
and	O
H.264/MPEG	B-Application
-4	I-Application
AVC	I-Application
.	O
</s>
<s>
A	O
WMV	B-Application
file	I-Application
uses	O
the	O
Advanced	B-Application
Systems	I-Application
Format	I-Application
(	O
ASF	O
)	O
container	O
format	O
to	O
encapsulate	O
the	O
encoded	O
multimedia	O
content	O
.	O
</s>
<s>
While	O
the	O
ASF	O
can	O
encapsulate	O
multimedia	O
in	O
other	O
encodings	O
than	O
those	O
the	O
WMV	B-Application
file	I-Application
standard	O
specifies	O
,	O
those	O
ASF	B-Application
files	I-Application
should	O
use	O
the	O
file	O
extension	O
and	O
not	O
the	O
file	O
extension	O
.	O
</s>
<s>
The	O
ASF	O
container	O
can	O
optionally	O
support	O
digital	O
rights	O
management	O
using	O
a	O
combination	O
of	O
elliptic	O
curve	O
cryptography	O
key	O
exchange	O
,	O
DES	B-Algorithm
block	O
cipher	O
,	O
a	O
custom	O
block	O
cipher	O
,	O
RC4	B-Algorithm
stream	O
cipher	O
and	O
the	O
SHA-1	B-Algorithm
hashing	O
function	O
.	O
</s>
<s>
Although	O
WMV	B-Device
is	O
generally	O
packed	O
into	O
the	O
ASF	O
container	O
format	O
,	O
it	O
can	O
also	O
be	O
put	O
into	O
the	O
Matroska	O
container	O
format	O
(	O
with	O
file	O
extension	O
)	O
,	O
or	O
AVI	O
container	O
format	O
(	O
extension	O
)	O
.	O
</s>
<s>
One	O
common	O
way	O
to	O
store	O
WMV	B-Device
in	O
an	O
AVI	O
file	O
is	O
to	O
use	O
the	O
WMV	B-Device
9	O
Video	B-Device
Compression	I-Device
Manager	I-Device
(	O
VCM	O
)	O
codec	O
implementation	O
.	O
</s>
<s>
Windows	B-Application
Media	I-Application
Video	I-Application
(	O
WMV	B-Device
)	O
is	O
the	O
most	O
recognized	O
video	B-Algorithm
compression	I-Algorithm
format	I-Algorithm
within	O
the	O
WMV	B-Device
family	O
.	O
</s>
<s>
Usage	O
of	O
the	O
term	O
WMV	B-Device
often	O
refers	O
to	O
the	O
Microsoft	O
Windows	B-Application
Media	I-Application
Video	I-Application
format	O
only	O
.	O
</s>
<s>
Its	O
main	O
competitors	O
are	O
MPEG-4	B-Application
AVC	I-Application
,	O
AVS	B-Algorithm
,	O
RealVideo	B-Algorithm
,	O
and	O
MPEG-4	B-Application
ASP	I-Application
.	O
</s>
<s>
The	O
first	O
version	O
of	O
the	O
format	O
,	O
WMV	B-Device
7	O
,	O
was	O
introduced	O
in	O
1999	O
,	O
and	O
was	O
built	O
upon	O
Microsoft	O
's	O
implementation	O
of	O
MPEG-4	B-Application
Part	I-Application
2	I-Application
.	O
</s>
<s>
Continued	O
proprietary	O
development	O
led	O
to	O
newer	O
versions	O
of	O
the	O
format	O
,	O
but	O
the	O
bit	O
stream	O
syntax	O
was	O
not	O
frozen	O
until	O
WMV	B-Device
9	O
.	O
</s>
<s>
While	O
all	O
versions	O
of	O
WMV	B-Device
support	O
variable	B-General_Concept
bit	I-General_Concept
rate	I-General_Concept
,	O
average	B-General_Concept
bit	I-General_Concept
rate	I-General_Concept
,	O
and	O
constant	B-General_Concept
bit	I-General_Concept
rate	I-General_Concept
,	O
WMV	B-Device
9	O
introduced	O
several	O
important	O
features	O
including	O
native	O
support	O
for	O
interlaced	O
video	O
,	O
non-square	O
pixels	B-Algorithm
,	O
and	O
frame	B-General_Concept
interpolation	I-General_Concept
.	O
</s>
<s>
WMV	B-Device
9	O
also	O
introduced	O
a	O
new	O
profile	O
titled	O
Windows	B-Application
Media	I-Application
Video	I-Application
9	O
Professional	O
,	O
which	O
is	O
activated	O
automatically	O
whenever	O
the	O
video	O
resolution	O
exceeds	O
300,000	O
pixels	B-Algorithm
(	O
e.g.	O
,	O
528	O
px	O
×	O
576	O
px	O
,	O
640	O
px	O
×	O
480	O
px	O
or	O
768	O
px	O
×	O
432	O
px	O
and	O
beyond	O
)	O
and	O
the	O
bitrate	O
1000kbit/s	O
.	O
</s>
<s>
The	O
Simple	O
and	O
Main	O
profile	O
levels	O
in	O
WMV	B-Device
9	O
are	O
compliant	O
with	O
the	O
same	O
profile	O
levels	O
in	O
the	O
VC-1	B-Operating_System
specification	O
.	O
</s>
<s>
The	O
Advanced	O
Profile	O
in	O
VC-1	B-Operating_System
is	O
implemented	O
in	O
a	O
new	O
WMV	B-Device
format	O
called	O
Windows	B-Application
Media	I-Application
Video	I-Application
9	O
Advanced	O
Profile	O
.	O
</s>
<s>
It	O
improves	O
compression	O
efficiency	O
for	O
interlaced	O
content	O
and	O
is	O
made	O
transport-independent	O
,	O
making	O
it	O
able	O
to	O
be	O
encapsulated	O
in	O
an	O
MPEG	O
transport	O
stream	O
or	O
RTP	B-Protocol
packet	O
format	O
.	O
</s>
<s>
The	O
format	O
is	O
not	O
compatible	O
with	O
previous	O
WMV	B-Device
9	O
formats	O
,	O
however	O
.	O
</s>
<s>
WMV	B-Device
is	O
a	O
mandatory	O
video	O
format	O
for	O
PlaysForSure-certified	O
online	O
stores	O
and	O
devices	O
,	O
as	O
well	O
as	O
Portable	B-Operating_System
Media	I-Operating_System
Center	I-Operating_System
devices	O
.	O
</s>
<s>
The	O
Microsoft	B-Device
Zune	I-Device
,	O
Xbox	B-Operating_System
360	I-Operating_System
,	O
Windows	O
Mobile-powered	O
devices	O
with	O
Windows	B-Device
Media	I-Device
Player	I-Device
,	O
as	O
well	O
as	O
many	O
uncertified	O
devices	O
,	O
support	O
the	O
format	O
.	O
</s>
<s>
WMV	B-Device
HD	O
mandates	O
the	O
use	O
of	O
WMV	B-Device
9	O
for	O
its	O
certification	O
program	O
,	O
at	O
quality	O
levels	O
specified	O
by	O
Microsoft	O
.	O
</s>
<s>
WMV	B-Device
used	O
to	O
be	O
the	O
only	O
supported	O
video	O
format	O
for	O
the	O
Microsoft	B-Application
Silverlight	I-Application
platform	O
,	O
but	O
the	O
H.264	B-Application
format	O
is	O
now	O
also	O
supported	O
starting	O
with	O
version	O
3	O
.	O
</s>
<s>
Windows	B-Application
Media	I-Application
Video	I-Application
Screen	O
(	O
WMV	B-Device
Screen	O
)	O
are	O
video	O
formats	O
that	O
specialise	O
in	O
screencast	B-Protocol
content	O
.	O
</s>
<s>
They	O
can	O
capture	O
live	O
screen	O
content	O
,	O
or	O
convert	O
video	O
from	O
third-party	O
screen-capture	O
programs	O
into	O
WMV	B-Device
9	O
Screen	O
files	O
.	O
</s>
<s>
They	O
work	O
best	O
when	O
the	O
source	O
material	O
is	O
mainly	O
static	O
and	O
contains	O
a	O
small	O
color	O
palette	B-Data_Structure
.	O
</s>
<s>
The	O
first	O
version	O
of	O
the	O
format	O
was	O
WMV	B-Device
7	O
Screen	O
.	O
</s>
<s>
The	O
second	O
version	O
,	O
WMV	B-Device
9	O
Screen	O
,	O
supports	O
VBR	O
encoding	O
in	O
addition	O
to	O
CBR	O
.	O
</s>
<s>
FourCCs	B-Application
for	O
the	O
formats	O
are	O
MSS1	O
,	O
MSS2	O
and	O
MSA1	O
.	O
</s>
<s>
Windows	B-Application
Media	I-Application
Video	I-Application
Image	O
(	O
WMV	B-Device
Image	O
)	O
is	O
a	O
video	O
slideshow	O
format	O
.	O
</s>
<s>
The	O
codec	O
achieves	O
a	O
higher	O
compression	O
ratio	O
and	O
image	O
quality	O
than	O
WMV	B-Device
9	O
for	O
still	O
images	O
as	O
files	O
encoded	O
with	O
WMV	B-Device
Image	O
store	O
static	O
images	O
rather	O
than	O
full-motion	O
video	O
.	O
</s>
<s>
Since	O
the	O
format	O
relies	O
on	O
the	O
decoder	O
(	O
player	O
)	O
to	O
generate	O
video	O
frames	O
in	O
real-time	O
,	O
playing	O
WMV	B-Device
Image	O
files	O
even	O
at	O
moderate	O
resolutions	O
(	O
e.g.	O
</s>
<s>
The	O
latest	O
version	O
of	O
the	O
format	O
,	O
WMV	B-Device
9.1	O
Image	O
,	O
used	O
by	O
Photo	B-Application
Story	I-Application
3	O
,	O
features	O
additional	O
transformation	O
effects	O
,	O
but	O
is	O
not	O
compatible	O
with	O
the	O
original	O
WMV	B-Device
9	O
Image	O
format	O
.	O
</s>
<s>
Hardware	O
support	O
for	O
WMV	B-Device
Image	O
is	O
available	O
from	O
Portable	B-Operating_System
Media	I-Operating_System
Centers	I-Operating_System
,	O
Windows	O
Mobile-powered	O
devices	O
with	O
Windows	B-Device
Media	I-Device
Player	I-Device
10	I-Device
Mobile	O
.	O
</s>
<s>
Since	O
no	O
known	O
domestic	O
DVD	O
player	O
supports	O
this	O
format	O
,	O
users	O
of	O
Photo	B-Application
Story	I-Application
3	O
wishing	O
to	O
generate	O
material	O
capable	O
of	O
being	O
played	O
in	O
a	O
DVD	O
player	O
will	O
first	O
have	O
to	O
convert	O
to	O
MPEG-2	B-Algorithm
before	O
burning	O
a	O
DVD	O
(	O
average	O
file	O
sizes	O
in	O
MPEG-2	B-Algorithm
are	O
5	O
to	O
6	O
times	O
the	O
.wmv	B-Application
file	O
)	O
.	O
</s>
<s>
Public	O
Name	O
FourCC	B-Application
Description	O
Microsoft	O
MPEG-4	O
version	O
1	O
MPG4	O
Video	O
for	O
Windows-based	O
codec	O
.	O
</s>
<s>
Non-standard	O
MPEG-4	O
codec	O
incompatible	O
with	O
the	O
later	O
standardized	O
version	O
of	O
MPEG-4	B-Application
Part	I-Application
2	I-Application
.	O
</s>
<s>
Non-compliant	O
with	O
finalized	O
MPEG-4	B-Application
part	I-Application
2	I-Application
standard	O
.	O
</s>
<s>
Non-compliant	O
with	O
finalized	O
MPEG-4	B-Application
part	I-Application
2	I-Application
standard	O
.	O
</s>
<s>
Eventually	O
locked	O
for	O
encoding	O
only	O
with	O
ASF	B-Application
files	I-Application
(	O
build	O
3688	O
and	O
earlier	O
could	O
also	O
encode	O
to	O
AVI	O
)	O
.VirtualDub	O
VirtualDub	O
documentation	O
:	O
codecs	O
,	O
Retrieved	O
on	O
2009-11-28	O
Microsoft	O
ISO	O
MPEG-4	O
version	O
1	O
MP4S	O
DirectX	O
Media	O
Objects	O
(	O
DMO	O
)	O
-based	O
codec	O
.	O
</s>
<s>
Microsoft	O
ISO	O
MPEG-4	O
version	O
1.1	O
M4S2	O
MPEG-4	O
Advanced	O
Simple	O
Profile	O
compliant.MPEG4	O
Part	O
2	O
Video	O
Decoder	O
MSDN	O
documentation	O
:	O
Profiles	O
and	O
Levels	O
,	O
Retrieved	O
on	O
2009-11-28	O
Windows	B-Application
Media	I-Application
Video	I-Application
7	O
WMV1DMO-based	O
codec	O
.	O
</s>
<s>
Windows	B-Device
Media	I-Device
Screen	O
7	O
MSS1	O
DMO-based	O
codec	O
.	O
</s>
<s>
Optimized	O
for	O
low-bitrate	O
sequential	O
screen	O
captures	O
or	O
screencasts	B-Protocol
.	O
</s>
<s>
Deprecated	O
in	O
favor	O
of	O
Windows	B-Device
Media	I-Device
9	I-Device
Screen	O
codec	O
.	O
</s>
<s>
Windows	B-Application
Media	I-Application
Video	I-Application
8	O
WMV2	O
DMO-based	O
codec	O
.	O
</s>
<s>
Windows	B-Application
Media	I-Application
Video	I-Application
9	O
WMV3	B-Device
DMO-based	O
codec	O
.	O
</s>
<s>
Video	B-Device
for	I-Device
Windows	I-Device
(	O
VfW/VCM	O
)	O
version	O
also	O
available	O
.	O
</s>
<s>
Windows	B-Application
Media	I-Application
Video	I-Application
9	O
Screen	O
MSS2	O
DMO-based	O
codec	O
.	O
</s>
<s>
Optimized	O
for	O
low-bitrate	O
sequential	O
screen	O
captures	O
or	O
screencasts	B-Protocol
.	O
</s>
<s>
Windows	B-Application
Media	I-Application
Video	I-Application
9.1	O
Image	O
WMVP	O
DMO-based	O
codec	O
.	O
</s>
<s>
Used	O
,	O
for	O
instance	O
,	O
by	O
Photo	B-Application
Story	I-Application
.	O
</s>
<s>
Windows	B-Application
Media	I-Application
Video	I-Application
9.1	O
Image	O
V2	O
WVP2	O
DMO-based	O
codec	O
.	O
</s>
<s>
Used	O
,	O
for	O
instance	O
,	O
by	O
Photo	B-Application
Story	I-Application
.	O
</s>
<s>
Windows	B-Application
Media	I-Application
Video	I-Application
9	O
Advanced	O
Profile	O
WMVA	O
DMO-based	O
codec	O
.	O
</s>
<s>
Deprecated	O
as	O
non-VC-1-compliant	O
.	O
</s>
<s>
Windows	B-Application
Media	I-Application
Video	I-Application
9	O
Advanced	O
Profile	O
WVC1	B-Operating_System
DMO-based	O
codec	O
.	O
</s>
<s>
VC-1	B-Operating_System
compliant	O
format	O
.	O
</s>
<s>
The	O
audio	O
format	O
used	O
in	O
conjunction	O
with	O
Windows	B-Application
Media	I-Application
Video	I-Application
is	O
typically	O
some	O
version	O
of	O
Windows	B-Application
Media	I-Application
Audio	I-Application
,	O
or	O
in	O
rarer	O
cases	O
,	O
the	O
deprecated	O
Sipro	O
ACELP.net	B-Algorithm
audio	O
format	O
.	O
</s>
<s>
Microsoft	O
recommends	O
that	O
ASF	B-Application
files	I-Application
containing	O
non-Windows	O
Media	O
formats	O
use	O
the	O
generic	O
file	O
extension	O
.	O
</s>
<s>
Software	O
that	O
can	O
play	O
WMV	B-Application
files	I-Application
includes	O
Windows	B-Device
Media	I-Device
Player	I-Device
,	O
RealPlayer	B-Application
,	O
MPlayer	B-Application
,	O
Media	B-Language
Player	I-Language
Classic	I-Language
,	O
VLC	B-Application
Media	I-Application
Player	I-Application
and	O
K-Multimedia	B-Application
Player	I-Application
.	O
</s>
<s>
The	O
Microsoft	B-Device
Zune	I-Device
media	O
management	O
software	O
supports	O
the	O
WMV	B-Device
format	O
,	O
but	O
uses	O
a	O
Zune-specific	O
variation	O
of	O
Windows	B-Device
Media	I-Device
DRM	O
which	O
is	O
used	O
by	O
PlaysForSure	O
.	O
</s>
<s>
Many	O
third-party	O
players	O
exist	O
for	O
various	O
platforms	O
such	O
as	O
Linux	B-Application
that	O
use	O
the	O
FFmpeg	B-Library
implementation	O
of	O
the	O
WMV	B-Device
format	O
.	O
</s>
<s>
On	O
the	O
Macintosh	B-Device
platform	O
,	O
Microsoft	O
released	O
a	O
PowerPC	B-Architecture
version	O
of	O
Windows	B-Device
Media	I-Device
Player	I-Device
for	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
in	O
2003	O
,	O
but	O
further	O
development	O
of	O
the	O
software	O
ceased	O
.	O
</s>
<s>
From	O
January	O
2006	O
to	O
May	O
2014	O
,	O
Microsoft	O
endorsed	O
and	O
distributed	O
the	O
3rd	O
party	O
Flip4Mac	B-Operating_System
,	O
a	O
QuickTime	B-Application
Component	O
developed	O
by	O
Telestream	O
that	O
allowed	O
Macintosh	B-Device
users	O
to	O
play	O
WMV	B-Application
files	I-Application
in	O
any	O
player	O
that	O
used	O
the	O
QuickTime	B-Application
framework	O
.	O
</s>
<s>
Telestream	O
ended	O
sales	O
of	O
Flip4Mac	B-Operating_System
on	O
1	O
July	O
2019	O
and	O
officially	O
ended	O
support	O
on	O
28	O
June	O
2020	O
.	O
</s>
<s>
The	O
Elmedia	O
player	O
,	O
which	O
can	O
play	O
WMV	B-Application
files	I-Application
on	O
Macintosh	B-Device
computers	I-Device
,	O
is	O
still	O
available	O
.	O
</s>
<s>
Many	O
programs	O
can	O
export	O
video	O
in	O
WMV	B-Device
format	O
;	O
a	O
few	O
examples	O
are	O
Windows	B-Application
Movie	I-Application
Maker	I-Application
,	O
Windows	B-Protocol
Media	I-Protocol
Encoder	I-Protocol
,	O
Microsoft	B-Application
Expression	I-Application
Encoder	I-Application
,	O
Sorenson	O
Squeeze	O
,	O
Sony	B-Application
Vegas	I-Application
Pro	I-Application
,	O
AVS	B-Application
Video	I-Application
Editor	I-Application
,	O
VSDC	O
Free	O
Video	O
Editor	O
,	O
Telestream	O
Episode	O
,	O
Telestream	O
FlipFactory	O
,	O
and	O
FFmpeg	B-Library
.	O
</s>
<s>
Programs	O
that	O
encode	O
using	O
the	O
WMV	B-Device
Image	O
format	O
include	O
Windows	B-Protocol
Media	I-Protocol
Encoder	I-Protocol
,	O
AVS	B-Application
Video	I-Application
Editor	I-Application
,	O
and	O
Photo	B-Application
Story	I-Application
.	O
</s>
<s>
While	O
none	O
of	O
the	O
WMV	B-Device
formats	O
themselves	O
contain	O
any	O
digital	O
rights	O
management	O
facilities	O
,	O
the	O
ASF	O
container	O
format	O
,	O
in	O
which	O
a	O
WMV	B-Device
stream	O
may	O
be	O
encapsulated	O
,	O
can	O
.	O
</s>
<s>
Windows	B-Device
Media	I-Device
DRM	O
,	O
which	O
can	O
be	O
used	O
in	O
conjunction	O
with	O
WMV	B-Device
,	O
supports	O
time-limited	O
subscription	O
video	O
services	O
such	O
as	O
those	O
offered	O
by	O
CinemaNow	O
.	O
</s>
<s>
Windows	B-Device
Media	I-Device
DRM	O
,	O
a	O
component	O
of	O
PlaysForSure	O
and	O
Windows	B-Application
Media	I-Application
Connect	I-Application
,	O
is	O
supported	O
on	O
many	O
modern	O
portable	O
video	O
devices	O
and	O
streaming	O
media	O
clients	O
such	O
as	O
the	B-Operating_System
Xbox	I-Operating_System
360	I-Operating_System
.	O
</s>
<s>
WMV	B-Device
has	O
been	O
the	O
subject	O
of	O
numerous	O
complaints	O
from	O
users	O
and	O
the	O
press	O
.	O
</s>
<s>
Users	O
dislike	O
the	O
digital	O
rights	O
management	O
system	O
which	O
is	O
sometimes	O
attached	O
to	O
WMV	B-Application
files	I-Application
.	O
</s>
<s>
In	O
2007	O
,	O
the	O
loss	O
of	O
the	O
ability	O
to	O
restore	O
licenses	O
for	O
WMV	B-Application
files	I-Application
in	O
the	O
Windows	B-Device
Media	I-Device
Player	I-Device
11	I-Device
was	O
not	O
positively	O
received	O
.	O
</s>
