<s>
FAAC	B-Operating_System
or	O
Freeware	B-Operating_System
Advanced	I-Operating_System
Audio	I-Operating_System
Coder	I-Operating_System
is	O
a	O
software	O
project	O
which	O
includes	O
the	O
AAC	B-Application
encoder	B-General_Concept
FAAC	B-Operating_System
and	O
decoder	B-Algorithm
FAAD2	B-Operating_System
.	O
</s>
<s>
It	O
supports	O
MPEG-2	B-Application
AAC	I-Application
as	O
well	O
as	O
MPEG-4	B-Application
AAC	I-Application
.	O
</s>
<s>
It	O
supports	O
several	O
MPEG-4	B-Algorithm
Audio	I-Algorithm
object	O
types	O
(	O
LC	O
,	O
Main	O
,	O
LTP	O
for	O
encoding	O
and	O
SBR	B-Algorithm
,	O
PS	O
,	O
ER	O
,	O
LD	O
for	O
decoding	O
)	O
,	O
file	O
formats	O
(	O
ADTS	O
AAC	B-Application
,	O
raw	O
AAC	B-Application
,	O
MP4	O
)	O
,	O
multichannel	O
and	O
gapless	O
encoding/decoding	O
and	O
MP4	O
metadata	O
tags	O
.	O
</s>
<s>
The	O
encoder	B-General_Concept
and	O
decoder	B-Algorithm
is	O
compatible	O
with	O
standard-compliant	O
audio	O
applications	O
using	O
one	O
or	O
more	O
of	O
these	O
object	O
types	O
and	O
facilities	O
.	O
</s>
<s>
FAAC	B-Operating_System
and	O
FAAD2	B-Operating_System
,	O
being	O
distributed	O
in	O
C	B-Language
source	O
code	O
form	O
,	O
can	O
be	O
compiled	B-Language
on	O
various	O
platforms	O
and	O
are	O
distributed	O
free	O
of	O
charge	O
.	O
</s>
<s>
FAAD2	B-Operating_System
is	O
free	B-Application
software	I-Application
.	O
</s>
<s>
FAAC	B-Operating_System
contains	O
some	O
code	O
which	O
is	O
published	O
as	O
Free	B-Application
Software	I-Application
,	O
but	O
as	O
a	O
whole	O
it	O
is	O
only	O
distributed	O
under	O
a	O
proprietary	O
license	O
.	O
</s>
<s>
FAAC	B-Operating_System
was	O
originally	O
written	O
by	O
Menno	O
Bakker	O
.	O
</s>
<s>
FAAC	B-Operating_System
stands	O
for	O
Freeware	B-Operating_System
Advanced	I-Operating_System
Audio	I-Operating_System
Coder	I-Operating_System
.	O
</s>
<s>
The	O
FAAC	B-Operating_System
encoder	B-General_Concept
is	O
an	O
audio	O
compression	O
computer	O
program	O
that	O
creates	O
AAC	B-Application
(	O
MPEG-2	O
AAC/MPEG	O
-4	O
AAC	B-Application
)	O
sound	O
files	O
from	O
other	O
formats	O
(	O
usually	O
,	O
CD-DA	O
audio	O
files	O
)	O
.	O
</s>
<s>
It	O
contains	O
a	O
library	O
(	O
libfaac	B-Operating_System
)	O
that	O
can	O
be	O
used	O
by	O
other	O
programs	O
.	O
</s>
<s>
AAC	B-Application
files	I-Application
are	O
commonly	O
used	O
in	O
computer	O
programs	O
and	O
portable	O
music	O
players	O
,	O
being	O
Apple	O
Inc.	O
'	O
s	O
recommended	O
format	O
for	O
the	O
company	O
's	O
iPod	B-Device
music	O
player	O
.	O
</s>
<s>
Some	O
of	O
the	O
features	O
that	O
FAAC	B-Operating_System
has	O
are	O
:	O
cross-platform	B-Operating_System
support	O
,	O
"	O
reasonably	O
"	O
fast	O
encoding	O
,	O
support	O
for	O
more	O
than	O
one	O
"	O
object	O
type	O
"	O
of	O
the	O
AAC	B-Application
format	I-Application
,	O
multi-channel	O
encoding	O
,	O
and	O
support	O
for	O
Digital	O
Radio	O
Mondiale	O
streams	O
.	O
</s>
<s>
The	O
MPEG-4	B-Algorithm
object	O
types	O
of	O
the	O
AAC	B-Application
format	I-Application
supported	O
by	O
FAAC	B-Operating_System
are	O
the	O
"	O
Low	O
Complexity	O
"	O
(	O
LC	O
)	O
,	O
"	O
Main	O
"	O
,	O
and	O
"	O
Long	O
Term	O
Prediction	O
"	O
(	O
LTP	O
)	O
.	O
</s>
<s>
The	O
MPEG-2	B-Application
AAC	I-Application
profiles	O
supported	O
by	O
FAAC	B-Operating_System
are	O
LC	O
and	O
Main	O
.	O
</s>
<s>
The	O
SBR	B-Algorithm
and	O
PS	O
object	O
types	O
are	O
not	O
supported	O
,	O
so	O
the	O
HE-AAC	O
and	O
HE-AACv2	O
profiles	O
are	O
also	O
not	O
supported	O
.	O
</s>
<s>
The	O
object	O
type	O
"	O
Low	O
Complexity	O
"	O
is	O
the	O
default	O
and	O
also	O
happens	O
to	O
be	O
used	O
in	O
videos	O
meant	O
to	O
be	O
playable	O
for	O
portable	O
players	O
(	O
like	O
Apple	O
's	O
iPod	B-Device
)	O
and	O
used	O
by	O
video-hosting	O
sites	O
(	O
like	O
YouTube	B-General_Concept
)	O
.	O
</s>
<s>
FAAC	B-Operating_System
has	O
been	O
evaluated	O
as	O
a	O
somewhat	O
"	O
lower	O
quality	O
"	O
option	O
than	O
other	O
aac	B-Application
encoders	O
.	O
</s>
<s>
FAAC	B-Operating_System
is	O
one	O
of	O
six	O
alternatives	O
that	O
Linux/Unix	O
users	O
have	O
for	O
creating	O
AAC	B-Application
files	I-Application
.	O
</s>
<s>
The	O
Fraunhofer-developed	O
"	O
FDK	B-Operating_System
AAC	I-Operating_System
"	O
encoder	B-General_Concept
library	O
included	O
as	O
part	O
of	O
Android	O
.	O
</s>
<s>
The	O
FDK	B-Operating_System
AAC	I-Operating_System
source	O
code	O
is	O
licensed	O
under	O
a	O
custom-copyleft	O
license	O
,	O
and	O
has	O
been	O
ported	O
to	O
other	O
platforms	O
as	O
libfdk-aac	O
.	O
</s>
<s>
The	O
Nero	O
AG-developed	O
"	O
Nero	B-Operating_System
AAC	I-Operating_System
Codec	I-Operating_System
"	O
,	O
which	O
has	O
a	O
proprietary	O
license	O
,	O
and	O
is	O
not	O
available	O
for	O
the	O
entire	O
range	O
of	O
hardware	B-General_Concept
architectures	I-General_Concept
that	O
these	O
operating	O
systems	O
are	O
able	O
to	O
run	O
.	O
</s>
<s>
Nero	O
no	O
longer	O
develops	O
this	O
encoder	B-General_Concept
,	O
but	O
the	O
package	O
is	O
still	O
available	O
,	O
and	O
it	O
remains	O
a	O
high-quality	O
option	O
for	O
AAC	B-Application
encoding	O
.	O
</s>
<s>
The	O
libavcodec	B-Language
native	O
AAC	B-Application
encoder	B-General_Concept
(	O
separate	O
versions	O
maintained	O
by	O
FFmpeg	B-Library
and	O
Libav	B-Language
)	O
was	O
experimental	O
but	O
considered	O
"	O
better	O
than	O
vo-aacenc	O
"	O
in	O
at	O
least	O
some	O
tests	O
.	O
</s>
<s>
It	O
was	O
written	O
by	O
Konstantin	O
Shishkov	O
,	O
and	O
released	O
under	O
version	O
2.1	O
of	O
the	O
LGPL	B-Application
.	O
</s>
<s>
The	O
AAC	B-Application
encoder	B-General_Concept
used	O
in	O
FFmpeg	B-Library
's	O
version	O
of	O
libavcodec	B-Language
was	O
significantly	O
improved	O
for	O
version	O
3.0	O
of	O
FFmpeg	B-Library
and	O
is	O
no	O
longer	O
considered	O
experimental	O
.	O
</s>
<s>
Libav	B-Language
has	O
not	O
merged	O
this	O
work	O
.	O
</s>
<s>
libvo_aacenc	O
,	O
the	O
Android	O
VisualOn	O
AAC	B-Application
encoder	B-General_Concept
.	O
</s>
<s>
This	O
encoder	B-General_Concept
was	O
replaced	O
in	O
Android	O
by	O
the	O
FDK	B-Operating_System
AAC	I-Operating_System
encoder	B-General_Concept
mentioned	O
above	O
,	O
and	O
is	O
considered	O
a	O
poor-quality	O
option	O
.	O
</s>
<s>
The	O
(	O
nonfree	O
)	O
libaacplus	O
which	O
implements	O
the	O
High-Efficiency	O
Advanced	B-Application
Audio	I-Application
Coding	I-Application
.	O
</s>
<s>
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
users	O
can	O
utilize	O
Apple	O
's	O
AAC	B-Application
encoder	B-General_Concept
with	O
the	O
command-line	O
afconvert	O
tool	O
.	O
</s>
<s>
FAAD2	B-Operating_System
is	O
Freeware	O
Advanced	O
Audio	O
(	O
AAC	B-Application
)	O
Decoder	B-Algorithm
including	O
SBR	B-Algorithm
decoding	O
.	O
</s>
<s>
It	O
is	O
MPEG-2	B-Algorithm
and	O
MPEG-4	B-Application
AAC	I-Application
decoder	B-Algorithm
and	O
supports	O
MPEG-4	B-Algorithm
audio	I-Algorithm
object	O
types	O
LC	O
,	O
Main	O
,	O
LTP	O
,	O
LD	O
,	O
ER	O
,	O
SBR	B-Algorithm
and	O
PS	O
,	O
which	O
can	O
be	O
combined	O
also	O
to	O
HE-AAC	O
and	O
HE-AACv2	O
Profile	O
(	O
AAC	B-Application
LC+SBR+PS	O
)	O
.	O
</s>
<s>
It	O
contains	O
a	O
library	O
(	O
libfaad	B-Operating_System
)	O
that	O
can	O
be	O
used	O
by	O
other	O
programs	O
.	O
</s>
<s>
FAAD	O
and	O
FAAD2	B-Operating_System
were	O
originally	O
written	O
by	O
Menno	O
Bakker	O
from	O
Nero	O
AG	O
.	O
</s>
<s>
FAAD2	B-Operating_System
is	O
the	O
successor	O
to	O
FAAD1	O
,	O
which	O
was	O
deprecated	O
.	O
</s>
<s>
FAAD	O
is	O
Freeware	B-Operating_System
Advanced	I-Operating_System
Audio	I-Operating_System
Decoder	I-Operating_System
.	O
</s>
<s>
It	O
was	O
first	O
released	O
in	O
2000	O
and	O
it	O
did	O
not	O
support	O
SBR	B-Algorithm
and	O
PS	O
audio	O
object	O
types	O
.	O
</s>
<s>
All	O
development	O
later	O
focused	O
in	O
FAAD2	B-Operating_System
.	O
</s>
<s>
The	O
SBR	B-Algorithm
decoding	O
support	O
(	O
HE-AAC	O
)	O
was	O
added	O
in	O
the	O
version	O
release	O
on	O
25	O
July	O
2003	O
.	O
</s>
<s>
FAAD2	B-Operating_System
version	O
2.0	O
was	O
released	O
on	O
6	O
February	O
2004	O
.	O
</s>
<s>
FAAC	B-Operating_System
contains	O
code	O
based	O
on	O
the	O
ISO	O
MPEG-4	B-Algorithm
reference	O
code	O
,	O
whose	O
license	O
is	O
not	O
compatible	O
with	O
the	O
LGPL	B-Application
license	I-Application
.	O
</s>
<s>
Only	O
the	O
FAAC	B-Operating_System
changes	O
to	O
this	O
ISO	O
MPEG-4	B-Algorithm
reference	O
code	O
are	O
licensed	O
under	O
the	O
LGPL	B-Application
license	I-Application
.	O
</s>
<s>
The	O
ISO	O
MPEG-4	B-Algorithm
reference	O
software	O
was	O
published	O
as	O
ISO/IEC	B-Algorithm
14496-5	I-Algorithm
(	O
MPEG-4	B-Algorithm
Part	I-Algorithm
5	I-Algorithm
:	O
Reference	O
software	O
)	O
and	O
it	O
is	O
freely	O
available	O
for	O
download	O
from	O
ISO	O
website	O
.	O
</s>
<s>
FAAD2	B-Operating_System
is	O
licensed	O
under	O
the	O
GPL	B-License
v2	O
(	O
and	O
later	O
GPL	B-License
versions	O
)	O
.	O
</s>
<s>
Code	O
from	O
FAAD2	B-Operating_System
is	O
copyright	O
of	O
Nero	O
AG	O
(	O
the	O
"	O
appropriate	O
copyright	O
message	O
"	O
mentioned	O
in	O
section	O
2c	O
of	O
the	O
GPLv2	O
)	O
.	O
</s>
<s>
Commercial	O
non-GPL	O
licensing	O
of	O
this	O
software	O
is	O
also	O
possible	O
.	O
</s>
<s>
FAAD	O
(	O
FAAD1	O
)	O
modifications	O
to	O
the	O
ISO	O
MPEG-4	B-Application
AAC	I-Application
reference	O
code	O
were	O
distributed	O
under	O
the	O
GPL	B-License
.	O
</s>
<s>
FAAC	B-Operating_System
and	O
FAAD2	B-Operating_System
are	O
used	O
in	O
the	O
following	O
software	O
products	O
and	O
libraries	B-Library
:	O
</s>
<s>
Avidemux	B-Language
video	O
editing	O
software	O
.	O
</s>
<s>
CDex	B-Application
uses	O
FAAC	B-Operating_System
encoder	B-General_Concept
.	O
</s>
<s>
FFmpeg	B-Library
supports	O
AAC	B-Application
encoding	O
through	O
external	O
library	O
libfaac	B-Operating_System
,	O
and	O
using	O
its	O
experimental	O
native	O
encoder	B-General_Concept
.	O
</s>
<s>
fre:ac	B-Language
uses	O
FAAC	B-Operating_System
and	O
FAAD2	B-Operating_System
for	O
AAC	B-Application
support	O
.	O
</s>
<s>
GStreamer	B-Language
multimedia	O
framework	O
uses	O
FAAC	B-Operating_System
and	O
FAAD	O
.	O
</s>
<s>
MPlayer	B-Application
uses	O
FAAD2	B-Operating_System
.	O
</s>
<s>
VLC	B-Application
media	I-Application
player	I-Application
uses	O
the	O
FAAC	B-Operating_System
(	O
encoder	B-General_Concept
)	O
and	O
FAAD	O
(	O
decoder	B-Algorithm
)	O
to	O
provide	O
support	O
for	O
AAC	B-Application
audio	O
.	O
</s>
<s>
There	O
is	O
also	O
other	O
software	O
that	O
uses	O
FAAC	B-Operating_System
libraries	B-Library
.	O
</s>
