<s>
The	O
Apple	B-Algorithm
Lossless	I-Algorithm
Audio	I-Algorithm
Codec	I-Algorithm
(	O
ALAC	B-Algorithm
)	O
,	O
also	O
known	O
as	O
Apple	B-Algorithm
Lossless	I-Algorithm
,	O
or	O
Apple	B-Algorithm
Lossless	I-Algorithm
Encoder	I-Algorithm
(	O
ALE	O
)	O
,	O
is	O
an	O
audio	O
coding	O
format	O
,	O
and	O
its	O
reference	O
audio	B-Algorithm
codec	I-Algorithm
implementation	O
,	O
developed	O
by	O
Apple	O
Inc	O
.	O
for	O
lossless	B-Algorithm
data	I-Algorithm
compression	I-Algorithm
of	O
digital	O
music	O
.	O
</s>
<s>
After	O
initially	O
keeping	O
it	O
proprietary	O
from	O
its	O
inception	O
in	O
2004	O
,	O
in	O
late	O
2011	O
Apple	O
made	O
the	O
codec	O
available	O
open	B-Application
source	I-Application
and	O
royalty-free	O
.	O
</s>
<s>
Traditionally	O
,	O
Apple	O
has	O
referred	O
to	O
the	O
codec	O
as	O
Apple	B-Algorithm
Lossless	I-Algorithm
,	O
though	O
more	O
recently	O
it	O
has	O
begun	O
to	O
use	O
the	O
abbreviated	O
term	O
ALAC	B-Algorithm
when	O
referring	O
to	O
the	O
codec	O
.	O
</s>
<s>
ALAC	B-Algorithm
supports	O
up	O
to	O
8	O
channels	O
of	O
audio	O
at	O
16	O
,	O
20	O
,	O
24	O
and	O
32	O
bit	O
depth	O
with	O
a	O
maximum	O
sample	O
rate	O
of	O
384kHz	O
.	O
</s>
<s>
ALAC	B-Algorithm
data	O
is	O
frequently	O
stored	O
within	O
an	O
MP4	O
container	O
with	O
the	O
filename	O
extension	O
.m4a	O
.	O
</s>
<s>
This	O
extension	O
is	O
also	O
used	O
by	O
Apple	O
for	O
lossy	B-Algorithm
AAC	B-Application
audio	O
data	O
in	O
an	O
MP4	O
container	O
(	O
same	O
container	O
,	O
different	O
audio	O
encoding	O
)	O
.	O
</s>
<s>
The	O
codec	O
can	O
also	O
be	O
used	O
by	O
the	O
.CAF	B-Application
file	O
type	O
container	O
,	O
though	O
this	O
is	O
much	O
less	O
common	O
.	O
</s>
<s>
ALAC	B-Algorithm
is	O
not	O
a	O
variant	O
of	O
AAC	B-Application
(	O
which	O
is	O
a	O
lossy	B-Algorithm
format	O
)	O
,	O
but	O
rather	O
an	O
unrelated	O
lossless	B-Algorithm
format	I-Algorithm
that	O
uses	O
linear	O
prediction	O
(	O
similar	O
to	O
other	O
lossless	B-Algorithm
codecs	I-Algorithm
)	O
.	O
</s>
<s>
ALAC	B-Algorithm
also	O
does	O
not	O
use	O
any	O
DRM	O
scheme	O
;	O
but	O
by	O
the	O
nature	O
of	O
the	O
MP4	O
container	O
,	O
it	O
is	O
feasible	O
that	O
DRM	O
could	O
be	O
applied	O
to	O
ALAC	B-Algorithm
much	O
in	O
the	O
same	O
way	O
it	O
is	O
applied	O
to	O
files	B-Operating_System
in	O
other	O
QuickTime	B-Application
containers	O
.	O
</s>
<s>
According	O
to	O
Apple	O
,	O
audio	O
files	B-Operating_System
compressed	O
with	O
its	O
lossless	B-Algorithm
codec	I-Algorithm
will	O
use	O
up	O
"	O
about	O
half	O
the	O
storage	O
space	O
"	O
that	O
the	O
uncompressed	B-General_Concept
data	O
would	O
require	O
.	O
</s>
<s>
Testers	O
using	O
a	O
selection	O
of	O
music	O
have	O
found	O
that	O
compressed	O
files	B-Operating_System
are	O
about	O
40%	O
to	O
60%	O
the	O
size	O
of	O
the	O
originals	O
depending	O
on	O
the	O
kind	O
of	O
music	O
,	O
which	O
is	O
similar	O
to	O
other	O
lossless	B-Algorithm
formats	I-Algorithm
.	O
</s>
<s>
ALAC	B-Algorithm
has	O
been	O
measured	O
to	O
require	O
around	O
four	O
times	O
as	O
much	O
CPU	O
power	O
to	O
decode	O
than	O
FLAC	B-Application
does	O
,	O
with	O
implications	O
for	O
battery	O
life	O
on	O
limited-power	O
devices	O
.	O
</s>
<s>
Still	O
the	O
format	O
has	O
been	O
recommended	O
for	O
older	O
iPod	B-Operating_System
devices	O
based	O
on	O
claims	O
of	O
lower	O
power	O
usage	O
.	O
</s>
<s>
Partly	O
because	O
of	O
the	O
use	O
of	O
an	O
MP4	O
container	O
,	O
ALAC	B-Algorithm
does	O
not	O
contain	O
integrated	O
error	O
checking	O
.	O
</s>
<s>
The	O
data	B-General_Concept
compression	I-General_Concept
software	O
for	O
encoding	O
into	O
ALAC	B-Algorithm
files	B-Operating_System
,	O
Apple	B-Algorithm
Lossless	I-Algorithm
Encoder	I-Algorithm
,	O
was	O
introduced	O
into	O
the	O
Mac	O
OS	O
X	O
Core	B-Operating_System
Audio	I-Operating_System
framework	O
on	O
April	O
28	O
,	O
2004	O
,	O
together	O
with	O
the	O
QuickTime	B-Application
6.5.1	I-Application
update	O
,	O
thus	O
making	O
it	O
available	O
in	O
iTunes	B-Operating_System
since	O
version	O
4.5	O
and	O
above	O
,	O
and	O
its	O
replacement	O
,	O
the	O
Music	O
application	O
.	O
</s>
<s>
On	O
March	O
5	O
,	O
2005	O
,	O
Hammerton	O
published	O
a	O
simple	O
open	B-Application
source	I-Application
decoder	O
written	O
in	O
the	O
C	B-Language
programming	I-Language
language	I-Language
on	O
the	O
basis	O
of	O
the	O
work	O
.	O
</s>
<s>
The	O
Apple	B-Algorithm
Lossless	I-Algorithm
Encoder	I-Algorithm
(	O
and	O
decoder	O
)	O
were	O
released	O
as	O
open	B-Application
source	I-Application
software	I-Application
under	O
the	O
Apache	B-Application
License	I-Application
version	O
2.0	O
on	O
October	O
27	O
,	O
2011	O
.	O
</s>
<s>
On	O
May	O
17	O
,	O
2021	O
,	O
Apple	O
announced	O
that	O
they	O
would	O
begin	O
offering	O
lossless	B-Algorithm
audio	O
in	O
Apple	B-Operating_System
Music	I-Operating_System
in	O
June	O
2021	O
,	O
with	O
all	O
lossless	B-Algorithm
music	O
being	O
encoded	O
using	O
ALAC	B-Algorithm
.	O
</s>
<s>
Other	O
lossless	B-Algorithm
codecs	I-Algorithm
,	O
such	O
as	O
FLAC	B-Application
and	O
Shorten	B-Operating_System
,	O
are	O
not	O
natively	O
supported	O
by	O
Apple	B-Operating_System
's	I-Operating_System
iTunes	I-Operating_System
nor	O
the	O
later	O
Music	B-Operating_System
app	I-Operating_System
(	O
either	O
the	O
macOS	O
or	O
Windows	O
versions	O
)	O
or	O
by	O
iOS	B-Operating_System
devices	I-Operating_System
running	O
iOS	B-Operating_System
10	I-Operating_System
or	O
below	O
.	O
</s>
<s>
In	O
order	O
to	O
be	O
played	O
through	O
the	O
iTunes	B-Operating_System
and	O
Music	B-Operating_System
app	I-Operating_System
on	O
iOS	O
,	O
audio	O
files	B-Operating_System
using	O
these	O
lossless	B-Algorithm
codecs	I-Algorithm
may	O
be	O
converted	O
via	O
various	O
third-party	O
tools	O
into	O
ALAC-encoded	O
files	B-Operating_System
with	O
no	O
change	O
in	O
fidelity	O
.	O
</s>
<s>
Third-party	O
applications	O
are	O
available	O
from	O
the	O
App	B-Application
Store	I-Application
to	O
play	O
such	O
files	B-Operating_System
without	O
converting	O
them	O
.	O
</s>
<s>
Devices	O
running	O
iOS	B-Operating_System
11	I-Operating_System
or	O
above	O
do	O
support	O
FLAC	B-Application
playback	O
natively	O
,	O
through	O
the	O
Files	B-Operating_System
application	O
only	O
.	O
</s>
<s>
The	O
method	O
of	O
importing	O
the	O
files	B-Operating_System
to	O
the	O
Apple	B-Operating_System
device	I-Operating_System
varies	O
between	O
applications	O
,	O
including	O
Files	B-Operating_System
,	O
as	O
there	O
is	O
currently	O
no	O
official	O
support	O
for	O
doing	O
so	O
.	O
</s>
<s>
All	O
current	O
iOS	B-Operating_System
devices	I-Operating_System
can	O
play	O
ALAC	B-Algorithm
encoded	O
files	B-Operating_System
.	O
</s>
<s>
The	O
open	B-Application
source	I-Application
library	O
libavcodec	B-Language
incorporates	O
both	O
a	O
decoder	O
and	O
an	O
encoder	O
for	O
the	O
ALAC	B-Algorithm
format	O
,	O
which	O
means	O
that	O
media	B-Device
players	I-Device
based	O
on	O
that	O
library	O
(	O
including	O
VLC	B-Application
media	I-Application
player	I-Application
and	O
MPlayer	B-Application
,	O
as	O
well	O
as	O
many	O
media	B-Operating_System
center	I-Operating_System
applications	O
for	O
home	O
theater	O
computers	O
,	O
such	O
as	O
Plex	B-Application
,	O
XBMC	B-Application
,	O
and	O
Boxee	B-Device
)	O
are	O
able	O
to	O
play	O
ALAC	B-Algorithm
files	B-Operating_System
.	O
</s>
<s>
As	O
of	O
2015	O
,	O
Windows	B-Operating_System
10	I-Operating_System
includes	O
support	O
for	O
ALAC	B-Algorithm
encoding	O
and	O
decoding	O
,	O
thereby	O
enabling	O
other	O
media	B-Device
players	I-Device
to	O
use	O
it	O
,	O
e.g.	O
</s>
<s>
Windows	B-Device
Media	I-Device
Player	I-Device
when	O
ripping	O
CDs	O
or	O
the	O
Spotify	B-Application
desktop	O
client	O
for	O
playback	O
of	O
local	O
.m4a	O
files	B-Operating_System
.	O
</s>
<s>
The	O
library	O
was	O
subsequently	O
optimized	O
for	O
ARM	O
processors	O
and	O
included	O
in	O
Rockbox	B-Application
.	O
</s>
<s>
Foobar2000	B-Application
will	O
play	O
ALAC	B-Algorithm
files	B-Operating_System
as	O
will	O
JRiver	B-Operating_System
Media	I-Operating_System
Center	I-Operating_System
and	O
BitPerfect	O
.	O
</s>
<s>
Lossless	B-Algorithm
music	O
via	O
ALAC	B-Algorithm
was	O
added	O
to	O
Apple	B-Operating_System
Music	I-Operating_System
in	O
June	O
2021	O
,	O
at	O
no	O
additional	O
cost	O
for	O
all	O
subscribers	O
.	O
</s>
<s>
The	O
maximum	O
fidelity	O
for	O
lossless	B-Algorithm
music	O
on	O
Apple	B-Operating_System
Music	I-Operating_System
is	O
24-bit	O
at	O
192kHz	O
.	O
</s>
