<s>
FLAC	B-Application
(	O
;	O
Free	B-Application
Lossless	I-Application
Audio	I-Application
Codec	I-Application
)	O
is	O
an	O
audio	O
coding	O
format	O
for	O
lossless	B-Algorithm
compression	I-Algorithm
of	O
digital	O
audio	O
,	O
developed	O
by	O
the	O
Xiph.Org	B-Application
Foundation	I-Application
,	O
and	O
is	O
also	O
the	O
name	O
of	O
the	O
free	B-Application
software	I-Application
project	O
producing	O
the	O
FLAC	B-Application
tools	O
,	O
the	O
reference	O
software	O
package	O
that	O
includes	O
a	O
codec	B-General_Concept
implementation	O
.	O
</s>
<s>
Digital	O
audio	O
compressed	O
by	O
FLAC	B-Application
's	O
algorithm	O
can	O
typically	O
be	O
reduced	O
to	O
between	O
50	O
and	O
70	O
percent	O
of	O
its	O
original	O
size	O
and	O
decompresses	O
to	O
an	O
identical	O
copy	O
of	O
the	O
original	O
audio	O
data	O
.	O
</s>
<s>
FLAC	B-Application
is	O
an	O
open	O
format	O
with	O
royalty-free	O
licensing	O
and	O
a	O
reference	O
implementation	O
which	O
is	O
free	B-Application
software	I-Application
.	O
</s>
<s>
FLAC	B-Application
has	O
support	O
for	O
metadata	O
tagging	O
,	O
album	O
cover	O
art	O
,	O
and	O
fast	O
seeking	O
.	O
</s>
<s>
Development	O
was	O
started	O
in	O
2000	O
by	O
Josh	B-Application
Coalson	I-Application
.	O
</s>
<s>
The	O
bitstream	O
format	O
was	O
frozen	O
when	O
FLAC	B-Application
entered	O
beta	O
stage	O
with	O
the	O
release	O
of	O
version	O
0.5	O
of	O
the	O
reference	O
implementation	O
on	O
15	O
January	O
2001	O
.	O
</s>
<s>
On	O
29	O
January	O
2003	O
,	O
the	O
Xiph.Org	B-Application
Foundation	I-Application
and	O
the	O
FLAC	B-Application
project	O
announced	O
the	O
incorporation	O
of	O
FLAC	B-Application
under	O
the	O
Xiph.org	B-Application
banner	O
.	O
</s>
<s>
Xiph.org	B-Application
is	O
home	O
to	O
other	O
free	O
compression	O
formats	O
such	O
as	O
Vorbis	B-Algorithm
,	O
Theora	B-Algorithm
,	O
Speex	B-Application
and	O
Opus	B-Algorithm
.	O
</s>
<s>
Version	O
1.3.0	O
was	O
released	O
on	O
26	O
May	O
2013	O
,	O
at	O
which	O
point	O
development	O
was	O
moved	O
to	O
the	O
Xiph.org	B-Application
git	O
repository	O
.	O
</s>
<s>
FLAC	B-Application
is	O
a	O
lossless	B-Algorithm
encoding	I-Algorithm
of	O
linear	B-Algorithm
pulse-code	I-Algorithm
modulation	I-Algorithm
data	O
.	O
</s>
<s>
The	O
FLAC	B-Application
algorithm	O
can	O
losslessly	B-Algorithm
convert	O
data	O
between	O
LPCM	B-Algorithm
and	O
FLAC	B-Application
,	O
but	O
is	O
not	O
guaranteed	O
to	O
be	O
lossless	B-Algorithm
when	O
converting	O
from	O
and	O
to	O
non-LPCM	O
formats	O
,	O
like	O
pulse-density	B-Algorithm
modulation	I-Algorithm
used	O
in	O
Direct	O
Stream	O
Digital	O
.	O
</s>
<s>
A	O
FLAC	B-Application
file	O
consists	O
of	O
the	O
magic	O
number	O
fLaC	B-Application
,	O
metadata	O
,	O
and	O
encoded	O
audio	O
.	O
</s>
<s>
Metadata	O
in	O
FLAC	B-Application
precedes	O
the	O
audio	O
.	O
</s>
<s>
FLAC	B-Application
uses	O
Vorbis	B-Algorithm
comments	O
for	O
textual	O
metadata	O
like	O
track	O
title	O
and	O
artist	O
name	O
.	O
</s>
<s>
The	O
FLAC	B-Application
encoding	O
algorithm	O
consists	O
of	O
multiple	O
stages	O
.	O
</s>
<s>
The	O
encoder	O
then	O
tries	O
to	O
find	O
a	O
good	O
mathematical	O
approximation	O
of	O
the	O
block	O
,	O
either	O
by	O
fitting	O
a	O
simple	O
polynomial	O
,	O
or	O
through	O
general	O
linear	B-Algorithm
predictive	I-Algorithm
coding	I-Algorithm
.	O
</s>
<s>
In	O
many	O
cases	O
,	O
a	O
description	O
of	O
the	O
approximation	O
and	O
the	O
encoded	O
residual	O
takes	O
up	O
less	O
space	O
than	O
using	O
pulse-code	B-Algorithm
modulation	I-Algorithm
.	O
</s>
<s>
As	O
FLAC	B-Application
compresses	B-Algorithm
losslessly	I-Algorithm
,	O
the	O
decoded	O
waveform	O
is	O
identical	O
to	O
the	O
waveform	O
before	O
encoding	O
.	O
</s>
<s>
Even	O
though	O
the	O
reference	O
encoder	O
uses	O
a	O
single	O
block	O
size	O
for	O
the	O
whole	O
stream	O
,	O
FLAC	B-Application
allows	O
the	O
block	O
size	O
in	O
samples	O
to	O
vary	O
per	O
block	O
.	O
</s>
<s>
For	O
user	O
's	O
convenience	O
,	O
the	O
reference	O
implementation	O
defines	O
9	O
compression	O
levels	O
,	O
which	O
are	O
presets	B-General_Concept
of	O
the	O
more	O
technical	O
parameters	O
to	O
the	O
encoding	O
algorithm	O
.	O
</s>
<s>
FLAC	B-Application
is	O
optimized	O
for	O
decoding	O
speed	O
at	O
the	O
expense	O
of	O
encoding	O
speed	O
.	O
</s>
<s>
Alongside	O
the	O
format	O
,	O
the	O
FLAC	B-Application
project	O
also	O
contains	O
a	O
free	B-License
and	I-License
open-source	I-License
reference	O
implementation	O
of	O
FLAC	B-Application
called	O
libFLAC	O
.	O
</s>
<s>
libFLAC	O
contains	O
facilities	O
to	O
encode	O
and	O
decode	O
FLAC	B-Application
data	O
and	O
to	O
manipulate	O
the	O
metadata	O
of	O
FLAC	B-Application
files	O
.	O
</s>
<s>
libFLAC++	O
,	O
an	O
object-oriented	B-Language
wrapper	O
around	O
libFLAC	O
for	O
C++	B-Language
,	O
and	O
the	O
command-line	B-Application
programs	I-Application
flac	B-Application
and	O
metaflac	O
,	O
are	O
also	O
part	O
of	O
the	O
reference	O
implementation	O
.	O
</s>
<s>
The	O
FLAC	B-Application
format	O
,	O
along	O
with	O
libFLAC	O
,	O
are	O
not	O
known	O
to	O
be	O
covered	O
by	O
any	O
patents	O
,	O
and	O
anyone	O
is	O
free	O
to	O
write	O
their	O
own	O
implementations	O
of	O
FLAC	B-Application
.	O
</s>
<s>
FLAC	B-Application
is	O
specifically	O
designed	O
for	O
efficient	O
packing	O
of	O
audio	O
data	O
,	O
unlike	O
general-purpose	O
lossless	B-Algorithm
algorithms	O
such	O
as	O
DEFLATE	B-Algorithm
,	O
which	O
are	O
used	O
in	O
ZIP	B-General_Concept
and	O
gzip	B-Application
.	O
</s>
<s>
While	O
ZIP	B-General_Concept
may	O
reduce	O
the	O
size	O
of	O
a	O
CD-quality	O
audio	O
file	O
by	O
10	O
–	O
20%	O
,	O
FLAC	B-Application
is	O
able	O
to	O
reduce	O
the	O
size	O
of	O
audio	O
data	O
by	O
40	O
–	O
50%	O
by	O
taking	O
advantage	O
of	O
the	O
characteristics	O
of	O
audio	O
.	O
</s>
<s>
The	O
technical	O
strengths	O
of	O
FLAC	B-Application
compared	O
to	O
other	O
lossless	B-Algorithm
formats	I-Algorithm
lie	O
in	O
its	O
ability	O
to	O
be	O
streamed	O
and	O
decoded	O
quickly	O
,	O
independent	O
of	O
compression	O
level	O
.	O
</s>
<s>
Since	O
FLAC	B-Application
is	O
a	O
lossless	B-Algorithm
scheme	O
,	O
it	O
is	O
suitable	O
as	O
an	O
archive	O
format	O
for	O
owners	O
of	O
CDs	O
and	O
other	O
media	O
who	O
wish	O
to	O
preserve	O
their	O
audio	O
collections	O
.	O
</s>
<s>
If	O
the	O
original	O
media	O
are	O
lost	O
,	O
damaged	O
,	O
or	O
worn	O
out	O
,	O
a	O
FLAC	B-Application
copy	O
of	O
the	O
audio	O
tracks	O
ensures	O
that	O
an	O
exact	O
duplicate	O
of	O
the	O
original	O
data	O
can	O
be	O
recovered	O
at	O
any	O
time	O
.	O
</s>
<s>
An	O
exact	O
restoration	O
from	O
a	O
lossy	O
copy	O
(	O
e.g.	O
,	O
MP3	B-Application
)	O
of	O
the	O
same	O
data	O
is	O
impossible	O
.	O
</s>
<s>
FLAC	B-Application
being	O
lossless	B-Algorithm
means	O
it	O
is	O
highly	O
suitable	O
for	O
transcoding	B-Algorithm
e.g.	O
</s>
<s>
to	O
MP3	B-Application
,	O
without	O
the	O
normally	O
associated	O
transcoding	B-Algorithm
quality	O
loss	O
between	O
one	O
lossy	O
format	O
and	O
another	O
.	O
</s>
<s>
If	O
a	O
CD	O
is	O
read	O
and	O
ripped	O
perfectly	O
to	O
FLAC	B-Application
files	O
,	O
the	O
CUE	O
file	O
allows	O
later	O
burning	O
of	O
an	O
audio	O
CD	O
that	O
is	O
identical	O
in	O
audio	O
data	O
to	O
the	O
original	O
CD	O
,	O
including	O
track	O
order	O
and	O
pregap	O
,	O
but	O
excluding	O
CD-Text	O
and	O
other	O
additional	O
data	O
such	O
as	O
lyrics	O
and	O
CD+G	O
graphics	O
.	O
</s>
<s>
The	O
reference	O
implementation	O
of	O
FLAC	B-Application
is	O
implemented	O
as	O
the	O
libFLAC	O
core	O
encoder	O
&	O
decoder	O
library	O
,	O
with	O
the	O
main	O
distributable	O
program	O
flac	B-Application
being	O
the	O
reference	O
implementation	O
of	O
the	O
libFLAC	O
API	O
.	O
</s>
<s>
This	O
codec	B-General_Concept
API	O
is	O
also	O
available	O
in	O
C++	B-Language
as	O
libFLAC++	O
.	O
</s>
<s>
The	O
reference	O
implementation	O
of	O
FLAC	B-Application
compiles	O
on	O
many	O
platforms	O
,	O
including	O
most	O
Unix	B-Application
(	O
such	O
as	O
Solaris	B-Application
,	O
BSD	B-Operating_System
)	O
and	O
Unix-like	B-Operating_System
(	O
including	O
Linux	B-Application
)	O
,	O
Microsoft	B-Application
Windows	I-Application
,	O
BeOS	B-Application
,	O
and	O
OS/2	B-Application
operating	B-General_Concept
systems	I-General_Concept
.	O
</s>
<s>
There	O
are	O
build-systems	O
for	O
autoconf/automake	O
,	O
MSVC	B-Application
,	O
Watcom	B-Application
C	I-Application
,	O
and	O
Xcode	B-Operating_System
.	O
</s>
<s>
There	O
is	O
currently	O
no	O
multicore	B-Architecture
support	O
in	O
libFLAC	O
,	O
but	O
utilities	O
such	O
as	O
GNU	B-Application
parallel	I-Application
and	O
various	O
graphical	O
frontends	O
can	O
be	O
used	O
to	O
spin	O
up	O
multiple	O
instances	O
of	O
the	O
encoder	O
.	O
</s>
<s>
FLAC	B-Application
playback	O
support	O
in	O
portable	O
audio	O
devices	O
and	O
dedicated	O
audio	O
systems	O
is	O
limited	O
compared	O
to	O
formats	O
such	O
as	O
MP3	B-Application
or	O
uncompressed	O
PCM	B-Algorithm
.	O
</s>
<s>
FLAC	B-Application
support	O
is	O
included	O
by	O
default	O
in	O
Windows	B-Operating_System
10	I-Operating_System
,	O
Android	B-Application
,	O
BlackBerry	B-Application
10	I-Application
and	O
Jolla	B-Operating_System
devices	O
.	O
</s>
<s>
In	O
2014	O
,	O
several	O
aftermarket	O
mobile	O
electronics	O
companies	O
introduced	O
multimedia	O
solutions	O
that	O
include	O
support	O
for	O
FLAC	B-Application
.	O
</s>
<s>
The	O
European	O
Broadcasting	O
Union	O
(	O
EBU	O
)	O
has	O
adopted	O
the	O
FLAC	B-Application
format	O
for	O
the	O
distribution	B-Application
of	O
high	O
quality	O
audio	O
over	O
its	O
Euroradio	O
network	O
.	O
</s>
<s>
The	O
Windows	B-Application
operating	I-Application
system	I-Application
has	O
supported	O
native	O
FLAC	B-Application
integration	O
since	O
the	O
introduction	O
of	O
Windows	B-Operating_System
10	I-Operating_System
.	O
</s>
<s>
The	O
Android	B-Application
operating	I-Application
system	I-Application
has	O
supported	O
native	O
FLAC	B-Application
playback	O
since	O
version	O
3.1	O
.	O
macOS	B-Operating_System
High	I-Operating_System
Sierra	I-Operating_System
and	O
iOS	B-Application
11	O
add	O
native	O
FLAC	B-Application
playback	O
support	O
.	O
</s>
<s>
Among	O
others	O
the	O
Pono	O
music	O
player	O
and	O
streaming	O
service	O
used	O
the	O
FLAC	B-Application
format	O
.	O
</s>
<s>
Bandcamp	O
insists	O
on	O
a	O
lossless	B-Algorithm
format	I-Algorithm
for	O
uploading	O
,	O
and	O
has	O
FLAC	B-Application
as	O
a	O
download	O
option	O
.	O
</s>
<s>
The	O
Wikimedia	O
Foundation	O
sponsored	O
a	O
free	B-License
and	I-License
open-source	I-License
online	O
ECMAScript	B-Language
FLAC	B-Application
tool	O
for	O
browsers	O
supporting	O
the	O
required	O
HTML5	B-Application
features	O
.	O
</s>
<s>
+	O
FLAC	B-Application
support	O
by	O
different	O
operating	B-General_Concept
systems	I-General_Concept
Microsoft	B-Application
Windows	I-Application
macOS	B-Application
Linux	B-Application
Android	B-Application
BlackBerry	B-Application
OS	I-Application
iOS	B-Application
Codec	B-General_Concept
support	O
Container	O
support	O
FLAC	B-Application
(	O
.flac	B-Application
)	O
Matroska	O
(	O
.mka	O
,	O
.mkv	O
)	O
FLAC	B-Application
(	O
.flac	B-Application
)	O
Core	B-Application
Audio	I-Application
Format	I-Application
(	O
.caf	B-Application
)	O
FLAC	B-Application
(	O
.flac	B-Application
)	O
Matroska	O
(	O
.mka	O
,	O
.mkv	O
)	O
Ogg	O
(	O
.oga	B-Algorithm
)	O
FLAC	B-Application
(	O
.flac	B-Application
)	O
FLAC	B-Application
(	O
.flac	B-Application
)	O
FLAC	B-Application
(	O
.flac	B-Application
)	O
Core	B-Application
Audio	I-Application
Format	I-Application
(	O
.caf	B-Application
)	O
Notes	O
Support	O
introduced	O
in	O
Windows	B-Operating_System
10	I-Operating_System
.	O
</s>
<s>
Support	O
introduced	O
in	O
High	B-Operating_System
Sierra	I-Operating_System
.	O
</s>
<s>
FLAC	B-Application
may	O
need	O
to	O
be	O
installed	O
depending	O
on	O
the	O
distribution	B-Application
.	O
</s>
<s>
Support	O
introduced	O
in	O
Android	B-Application
3.1	O
Support	O
introduced	O
in	O
BlackBerry	B-Application
OS	I-Application
5.0	O
Support	O
introduced	O
in	O
iOS	B-Application
11	O
(	O
but	O
depends	O
on	O
hardware	O
used	O
)	O
.	O
</s>
<s>
Various	O
other	O
containers	O
are	O
supported	O
,	O
independently	O
from	O
used	O
operating	B-General_Concept
system	I-General_Concept
,	O
depending	O
on	O
used	O
playback	O
software	O
.	O
</s>
