<s>
A	O
video	B-General_Concept
file	I-General_Concept
format	I-General_Concept
is	O
a	O
type	O
of	O
file	O
format	O
for	O
storing	O
digital	O
video	O
data	O
on	O
a	O
computer	O
system	O
.	O
</s>
<s>
Video	O
is	O
almost	O
always	O
stored	O
using	O
lossy	B-Algorithm
compression	I-Algorithm
to	O
reduce	O
the	O
file	O
size	O
.	O
</s>
<s>
A	O
video	B-General_Concept
file	I-General_Concept
normally	O
consists	O
of	O
a	O
container	O
(	O
e.g.	O
</s>
<s>
in	O
the	O
Matroska	O
format	O
)	O
containing	O
visual	O
(	O
video	O
without	O
audio	O
)	O
data	O
in	O
a	O
video	B-Algorithm
coding	I-Algorithm
format	I-Algorithm
(	O
e.g.	O
</s>
<s>
VP9	B-Algorithm
)	O
alongside	O
audio	O
data	O
in	O
an	O
audio	O
coding	O
format	O
(	O
e.g.	O
</s>
<s>
Opus	B-Algorithm
)	O
.	O
</s>
<s>
A	O
standardized	O
(	O
or	O
in	O
some	O
cases	O
de	O
facto	O
standard	O
)	O
video	B-General_Concept
file	I-General_Concept
type	I-General_Concept
such	O
as	O
.webm	B-Application
is	O
a	O
profile	O
specified	O
by	O
a	O
restriction	O
on	O
which	O
container	O
format	O
and	O
which	O
video	O
and	O
audio	O
compression	O
formats	O
are	O
allowed	O
.	O
</s>
<s>
The	O
coded	O
video	O
and	O
audio	O
inside	O
a	O
video	B-General_Concept
file	I-General_Concept
container	O
(	O
i.e.	O
</s>
<s>
not	O
headers	O
,	O
footers	O
,	O
and	O
metadata	O
)	O
is	O
called	O
the	O
essence	B-General_Concept
.	O
</s>
<s>
A	O
program	O
(	O
or	O
hardware	O
)	O
which	O
can	O
decode	O
compressed	O
video	O
or	O
audio	O
is	O
called	O
a	O
codec	B-General_Concept
;	O
playing	O
or	O
encoding	O
a	O
video	B-General_Concept
file	I-General_Concept
will	O
sometimes	O
require	O
the	O
user	O
to	O
install	O
a	O
codec	B-General_Concept
library	O
corresponding	O
to	O
the	O
type	O
of	O
video	O
and	O
audio	O
coding	O
used	O
in	O
the	O
file	O
.	O
</s>
<s>
That	O
is	O
the	O
case	O
with	O
some	O
video	B-General_Concept
file	I-General_Concept
formats	I-General_Concept
,	O
such	O
as	O
WebM	B-Application
(	O
.webm	B-Application
)	O
,	O
Windows	B-Application
Media	I-Application
Video	I-Application
(	O
.wmv	B-Application
)	O
,	O
Flash	B-Operating_System
Video	I-Operating_System
(	O
.flv	B-Operating_System
)	O
,	O
and	O
Ogg	B-Algorithm
Video	I-Algorithm
(	O
.ogv	B-Algorithm
)	O
,	O
each	O
of	O
which	O
can	O
only	O
contain	O
a	O
few	O
well-defined	O
subtypes	O
of	O
video	O
and	O
audio	O
coding	O
formats	O
,	O
making	O
it	O
relatively	O
easy	O
to	O
know	O
which	O
codec	B-General_Concept
will	O
play	O
the	O
file	O
.	O
</s>
<s>
In	O
contrast	O
to	O
that	O
,	O
some	O
very	O
general-purpose	O
container	O
types	O
like	O
AVI	O
(	O
.avi	O
)	O
and	O
QuickTime	O
(	O
.mov	B-Application
)	O
can	O
contain	O
video	O
and	O
audio	O
in	O
almost	O
any	O
format	O
,	O
and	O
have	O
file	O
extensions	O
named	O
after	O
the	O
container	O
type	O
,	O
making	O
it	O
very	O
hard	O
for	O
the	O
end	O
user	O
to	O
use	O
the	O
file	O
extension	O
to	O
derive	O
which	O
codec	B-General_Concept
or	O
program	O
to	O
use	O
to	O
play	O
the	O
files	O
.	O
</s>
<s>
The	O
free	B-Application
software	I-Application
FFmpeg	B-Library
project	O
's	O
libraries	O
have	O
very	O
wide	O
support	O
for	O
encoding	O
and	O
decoding	O
video	B-General_Concept
file	I-General_Concept
formats	I-General_Concept
.	O
</s>
<s>
For	O
example	O
,	O
Google	O
uses	O
ffmpeg	B-Library
to	O
support	O
a	O
wide	O
range	O
of	O
upload	O
video	O
formats	O
for	O
YouTube	O
.	O
</s>
<s>
One	O
widely	O
used	O
media	O
player	O
using	O
the	O
ffmpeg	B-Library
libraries	O
is	O
the	O
free	B-Application
software	I-Application
VLC	B-Application
media	I-Application
player	I-Application
,	O
which	O
can	O
play	O
most	O
video	B-General_Concept
files	I-General_Concept
that	O
end	O
users	O
will	O
encounter	O
.	O
</s>
<s>
Name	O
File	O
extension(s )	O
Container	O
format	O
Video	O
coding	O
format(s )	O
Audio	O
coding	O
format(s )	O
Notes	O
WebM	B-Application
.webm	B-Application
Matroska	O
VP8	B-Algorithm
,	O
VP9	B-Algorithm
,	O
AV1	B-Application
Vorbis	B-Algorithm
,	O
Opus	B-Algorithm
Royalty-free	O
format	O
created	O
for	O
HTML5	O
video	O
.	O
</s>
<s>
Matroska	O
.mkv	O
Matroska	O
any	O
any	O
Flash	B-Operating_System
Video	I-Operating_System
(	O
FLV	B-Operating_System
)	O
.flv	B-Operating_System
FLV	B-Operating_System
VP6	B-Algorithm
,	O
Sorenson	O
Spark	O
,	O
Screen	O
video	O
,	O
Screen	O
video	O
2	O
,	O
H.264	B-Application
MP3	B-Application
,	O
ADPCM	B-Algorithm
,	O
Nellymoser	B-Algorithm
,	O
Speex	B-Application
,	O
AAC	B-Application
Use	O
of	O
the	O
H.264	B-Application
and	O
AAC	B-Application
compression	O
formats	O
in	O
the	O
FLV	B-Operating_System
file	I-Operating_System
format	O
has	O
some	O
limitations	O
and	O
authors	O
of	O
Flash	O
Player	O
strongly	O
encourage	O
everyone	O
to	O
embrace	O
the	O
new	O
standard	O
F4V	B-Operating_System
file	O
formatKaourantin.net	O
(	O
31	O
October	O
2007	O
)	O
Tinic	O
Uro	O
New	O
File	O
Extensions	O
and	O
MIME	O
Types	O
,	O
Retrieved	O
on	O
2009-08-03	O
de	O
facto	O
standard	O
for	O
web-based	O
streaming	O
video	O
(	O
over	O
RTMP	B-Operating_System
)	O
.	O
</s>
<s>
F4V	B-Operating_System
.flv	B-Operating_System
MPEG-4	O
Part	O
12	O
H.264	B-Application
MP3	B-Application
,	O
AAC	B-Application
Replacement	O
for	O
FLV	B-Operating_System
.	O
</s>
<s>
Vob	O
.vob	O
VOB	O
H.262/MPEG	B-Algorithm
-2	I-Algorithm
Part	I-Algorithm
2	I-Algorithm
or	O
MPEG-1	B-Algorithm
Part	O
2	O
PCM	B-Algorithm
,	O
DTS	O
,	O
MPEG-1	B-Algorithm
,	O
Audio	O
Layer	O
II	O
(	O
MP2	O
)	O
,	O
or	O
Dolby	O
Digital	O
(	O
AC-3	O
)	O
Files	O
in	O
VOB	O
format	O
have	O
.vob	O
filename	O
extension	O
and	O
are	O
typically	O
stored	O
in	O
the	O
VIDEO_TS	O
folder	O
at	O
the	O
root	O
of	O
a	O
DVD	O
.	O
</s>
<s>
Ogg	B-Algorithm
Video	I-Algorithm
.ogv	B-Algorithm
,	O
.ogg	O
Ogg	B-Algorithm
Theora	I-Algorithm
,	O
Dirac	B-Application
Vorbis	B-Algorithm
,	O
FLAC	B-Application
Dirac	B-Application
.drc	O
?	O
</s>
<s>
Dirac	B-Application
?	O
</s>
<s>
GIF	O
.gif	O
N/A	O
N/A	O
none	O
Simple	O
animation	O
,	O
inefficient	O
compression	O
,	O
no	O
sound	O
,	O
widely	O
supported	O
Video	O
alternative	O
to	O
GIF	O
.gifv	O
HTML	O
any	O
none	O
Not	O
standardized	O
,	O
and	O
not	O
a	O
real	B-Algorithm
video	I-Algorithm
file	O
in	O
the	O
classical	O
meaning	O
since	O
it	O
merely	O
references	O
the	O
real	B-Algorithm
video	I-Algorithm
file	O
(	O
e.g.	O
</s>
<s>
a	O
.webm	B-Application
file	O
)	O
,	O
which	O
has	O
to	O
exist	O
separately	O
elsewhere	O
.	O
</s>
<s>
AVI	O
.avi	O
AVI	O
any	O
any	O
Uses	O
RIFFMPEG	O
Transport	O
Stream.MTS	O
,	O
.M2TS	O
,	O
.TSAVCHDAVCHD	O
(	O
MPEG-4	O
/	O
H.264	B-Application
)	O
Dolby	O
AC-3	O
or	O
uncompressed	O
linear	O
PCMThe	O
standard	O
video	O
format	O
used	O
by	O
many	O
Sony	O
and	O
Panasonic	O
HD	O
camcorders	O
.	O
</s>
<s>
QuickTime	B-Application
File	I-Application
Format	I-Application
.mov	B-Application
,	O
.qt	B-Application
QuickTime	O
many	O
AAC	B-Application
,	O
MP3	B-Application
,	O
others	O
Windows	B-Application
Media	I-Application
Video	I-Application
.wmv	B-Application
ASF	B-Application
Windows	B-Application
Media	I-Application
Video	I-Application
,	O
Windows	B-Application
Media	I-Application
Video	I-Application
Screen	O
,	O
Windows	B-Application
Media	I-Application
Video	I-Application
Image	O
Windows	O
Media	O
Audio	O
,	O
Sipro	O
ACELP.net	O
Raw	O
video	O
format	O
.yuv	O
Further	O
documentation	O
needed	O
Does	O
n't	O
apply	O
Does	O
n't	O
apply	O
Supports	O
all	O
resolutions	O
,	O
sampling	O
structures	O
,	O
and	O
frame	O
rates	O
RealMedia	O
(	O
RM	O
)	O
.rm	O
RealMedia	O
RealVideo	B-Algorithm
RealAudio	B-Algorithm
Made	O
for	O
RealPlayer	B-Application
RealMedia	O
Variable	O
Bitrate	O
(	O
RMVB	O
)	O
.rmvb	O
RealMedia	O
Variable	O
Bitrate	O
RealVideo	B-Algorithm
RealAudio	B-Algorithm
Made	O
for	O
RealPlayer	B-Application
VivoActive	B-Algorithm
(	O
VIV	O
)	O
.viv	O
VIV	O
based	O
upon	O
H.263	B-Algorithm
video	O
G.723	O
ADPCM	B-Algorithm
audio	O
(	O
not	O
the	O
G.723.1	O
speech	O
codec	B-General_Concept
)	O
Made	O
for	O
VivoActive	B-Algorithm
Player	O
Advanced	B-Application
Systems	I-Application
Format	I-Application
(	O
ASF	B-Application
)	O
.asf	B-Application
ASF	B-Application
any	O
any	O
AMV	B-Algorithm
video	I-Algorithm
format	I-Algorithm
.amv	B-Algorithm
Modified	O
version	O
of	O
AVI	O
"	O
AMV	O
codec	B-General_Concept
tools	O
"	O
code.google.com	O
Variant	O
of	O
Motion	B-Application
JPEG	I-Application
Variant	O
of	O
IMA	O
,	O
ADPCM	B-Algorithm
Proprietary	O
video	B-General_Concept
file	I-General_Concept
format	I-General_Concept
produced	O
for	O
MP4	O
players	O
and	O
S1	O
MP3	B-Application
players	O
with	O
video	O
playback	O
MPEG-4	O
Part	O
14	O
(	O
MP4	O
)	O
.mp4	O
,	O
.m4p	O
(	O
with	O
DRM	O
)	O
,	O
.m4v	B-Application
MPEG-4	O
Part	O
12	O
H.264	B-Application
,	O
H.265	B-Algorithm
,	O
MPEG-4	B-Application
Part	I-Application
2	I-Application
,	O
MPEG-2	B-Algorithm
,	O
MPEG-1	B-Algorithm
Advanced	B-Application
Audio	I-Application
Coding	I-Application
,	O
MP3	B-Application
,	O
others	O
MPEG-1	B-Algorithm
.mpg	O
,	O
.mp2	O
,	O
.mpeg	B-Algorithm
,	O
.mpe	O
,	O
.mpv	O
MPEG-1	B-Algorithm
part	O
1	O
MPEG-1	B-Algorithm
part	O
2	O
MPEG-1	B-Algorithm
Audio	O
Layer	O
I	O
,	O
MPEG-1	B-Algorithm
Audio	O
Layer	O
I	O
,	O
MPEG-1	B-Application
Audio	I-Application
Layer	I-Application
III	I-Application
(	O
MP3	B-Application
)	O
Old	O
,	O
but	O
very	O
widely	O
used	O
due	O
to	O
installed	O
base	O
.	O
</s>
<s>
MPEG-2	B-Algorithm
–	O
Video	O
.mpg	O
,	O
.mpeg	B-Algorithm
,	O
.m2v	O
?	O
</s>
<s>
H.262	B-Algorithm
AAC	B-Application
,	O
MP3	B-Application
,	O
MPEG-2	B-Algorithm
Part	O
3	O
,	O
others	O
M4V	B-Application
.m4v	B-Application
MPEG-4	O
Part	O
12	O
H.264	B-Application
AAC	B-Application
,	O
Dolby	O
Digital	O
Developed	O
by	O
Apple	O
,	O
used	O
in	O
iTunes	O
.	O
</s>
<s>
Samsung	O
video	O
format	O
for	O
portable	O
players	O
3GPP	O
.3gp	O
MPEG-4	O
Part	O
12	O
MPEG-4	B-Application
Part	I-Application
2	I-Application
,	O
H.263	B-Algorithm
,	O
H.264	B-Application
AMR-NB	B-Algorithm
,	O
AMR-WB	B-Algorithm
,	O
AMR-WB	B-Algorithm
+	I-Algorithm
,	O
AAC-LC	B-Application
,	O
HE-AAC	O
v1	O
or	O
Enhanced	O
aacPlus	O
(	O
HE-AAC	O
v2	O
)	O
Common	O
video	O
format	O
for	O
cell	O
phones	O
3GPP2	O
.3g2	O
MPEG-4	O
Part	O
12	O
MPEG-4	B-Application
Part	I-Application
2	I-Application
,	O
H.263	B-Algorithm
,	O
H.264	B-Application
AMR-NB	B-Algorithm
,	O
AMR-WB	B-Algorithm
,	O
AMR-WB	B-Algorithm
+	I-Algorithm
,	O
AAC-LC	B-Application
,	O
HE-AAC	O
v1	O
or	O
Enhanced	O
aacPlus	O
(	O
HE-AAC	O
v2	O
)	O
,	O
EVRC	B-Algorithm
,	O
SMV	B-Application
or	O
VMR-WB	B-Algorithm
Common	O
video	O
format	O
for	O
cell	O
phones	O
Material	O
Exchange	O
Format	O
(	O
MXF	O
)	O
.mxf	O
MXF	O
?	O
</s>
<s>
used	O
by	O
Quake	B-Application
3	I-Application
Nullsoft	O
Streaming	O
Video	O
(	O
NSV	O
)	O
.nsv	O
NSV	O
?	O
</s>
