<s>
WavPack	B-Application
is	O
a	O
free	B-License
and	I-License
open-source	I-License
lossless	B-Algorithm
audio	O
compression	O
format	O
and	O
application	O
implementing	O
the	O
format	O
.	O
</s>
<s>
It	O
is	O
unique	O
in	O
the	O
way	O
that	O
it	O
supports	O
hybrid	O
audio	O
compression	O
alongside	O
normal	O
compression	O
which	O
is	O
similar	O
to	O
how	O
FLAC	B-Application
works	O
.	O
</s>
<s>
It	O
also	O
supports	O
compressing	O
a	O
wide	O
variety	O
of	O
lossless	B-Algorithm
formats	I-Algorithm
,	O
including	O
various	O
variants	O
of	O
PCM	B-Algorithm
and	O
also	O
DSD	O
as	O
used	O
in	O
SACDs	O
,	O
together	O
with	O
its	O
support	O
for	O
surround	O
audio	O
.	O
</s>
<s>
WavPack	B-Application
compression	O
can	O
compress	O
(	O
and	O
restore	O
)	O
8-	O
,	O
16-	O
,	O
24-	O
,	O
and	O
32-bit	O
fixed-point	O
,	O
and	O
32-bit	O
floating-point	B-Algorithm
PCM	B-Algorithm
audio	I-Algorithm
files	O
in	O
the	O
.WAV	O
file	O
format	O
.	O
</s>
<s>
Like	O
other	O
lossless	B-Algorithm
compression	I-Algorithm
schemes	O
,	O
the	O
data	O
reduction	O
rate	O
varies	O
with	O
the	O
source	O
,	O
but	O
it	O
is	O
generally	O
between	O
30%	O
and	O
70%	O
for	O
typical	O
popular	O
music	O
and	O
somewhat	O
better	O
than	O
that	O
for	O
classical	O
music	O
and	O
other	O
sources	O
with	O
greater	O
dynamic	O
range	O
.	O
</s>
<s>
WavPack	B-Application
also	O
incorporates	O
a	O
"	O
hybrid	O
"	O
mode	O
,	O
which	O
still	O
provides	O
the	O
features	O
of	O
lossless	B-Algorithm
compression	I-Algorithm
,	O
but	O
creates	O
two	O
files	O
:	O
a	O
relatively	O
small	O
,	O
high-quality	O
,	O
lossy	O
file	O
(	O
.wv	B-Application
)	O
that	O
can	O
be	O
used	O
by	O
itself	O
;	O
and	O
a	O
"	O
correction	O
"	O
file	O
(	O
.wvc	O
)	O
that	O
,	O
when	O
combined	O
with	O
the	O
lossy	O
file	O
,	O
provides	O
full	O
lossless	B-Algorithm
restoration	O
.	O
</s>
<s>
This	O
allows	O
the	O
use	O
of	O
lossy	O
and	O
lossless	B-Algorithm
codecs	I-Algorithm
together	O
.	O
</s>
<s>
Native	O
support	O
in	O
WavPack	B-Application
5.x	O
for	O
compressing	O
Direct	O
Stream	O
Digital	O
without	O
converting	O
the	O
source	O
file	O
to	O
PCM	B-Algorithm
.	O
</s>
<s>
David	O
Bryant	O
started	O
development	O
on	O
WavPack	B-Application
in	O
mid-1998	O
with	O
the	O
release	O
of	O
version	O
1.0	O
(	O
1998-08-15	O
)	O
.	O
</s>
<s>
This	O
first	O
version	O
compressed	O
and	O
decompressed	O
audio	O
losslessly	B-Algorithm
,	O
and	O
it	O
already	O
featured	O
one	O
of	O
the	O
best	O
efficiency	O
vs.	O
speed	O
ratios	O
among	O
lossless	B-Algorithm
encoders	I-Algorithm
.	O
</s>
<s>
In	O
1999	O
,	O
version	O
3.0	O
(	O
12	O
September	O
1999	O
)	O
was	O
released	O
,	O
with	O
a	O
new	O
"	O
fast	O
mode	O
"	O
(	O
albeit	O
with	O
reduced	O
compression	O
ratio	O
)	O
,	O
compression	O
of	O
raw	O
(	O
headerless	O
)	O
PCM	B-Algorithm
audio	I-Algorithm
files	O
,	O
and	O
error	O
detection	O
using	O
a	O
32-bit	O
cyclic	O
redundancy	O
check	O
.	O
</s>
<s>
A	O
feature	O
added	O
in	O
late	O
3.x	O
versions	O
is	O
the	O
"	O
hybrid	O
"	O
mode	O
where	O
the	O
encoder	O
generates	O
a	O
lossy	O
file	O
and	O
a	O
correction	O
file	O
such	O
that	O
both	O
can	O
be	O
decompressed	O
back	O
to	O
a	O
PCM	B-Algorithm
stream	O
that	O
has	O
same	O
quality	O
as	O
the	O
original	O
.	O
</s>
<s>
Some	O
software	O
supports	O
the	O
format	O
natively	O
(	O
like	O
DeaDBeeF	B-Language
,	O
foobar2000	B-Application
,	O
and	O
Jack	O
!	O
</s>
<s>
The	O
official	O
WavPack	B-Application
website	O
offers	O
plugins	O
for	O
Winamp	B-Application
,	O
Nero	B-Application
Burning	I-Application
ROM	I-Application
,	O
MediaChest	O
2.1	O
,	O
and	O
several	O
other	O
applications	O
,	O
as	O
well	O
as	O
a	O
DirectShow	B-Library
filter	O
.	O
</s>
<s>
,	O
by	O
the	O
author	O
of	O
foobar2000	B-Application
,	O
as	O
well	O
as	O
foobar2000	B-Application
itself	O
,	O
and	O
Asunder	B-Language
allow	O
ripping	O
Audio	O
CDs	O
directly	O
into	O
Wavpack	B-Application
files	O
.	O
</s>
<s>
Linux	B-Application
support	O
is	O
available	O
with	O
a	O
native	O
port	O
.	O
</s>
<s>
FFmpeg	B-Library
has	O
a	O
native	O
WavPack	B-Application
encoder	O
,	O
which	O
may	O
be	O
combined	O
with	O
software	O
like	O
GNU	B-Application
parallel	I-Application
to	O
use	O
multiple	O
CPU	O
cores	O
to	O
quickly	O
transcode	O
other	O
lossless	B-Algorithm
formats	I-Algorithm
into	O
WavPack	B-Application
,	O
and	O
from	O
WavPack	B-Application
to	O
any	O
format	O
that	O
FFmpeg	B-Library
supports	O
,	O
without	O
the	O
need	O
for	O
additional	O
software	O
.	O
</s>
<s>
Cowon	O
A3	O
PMP	O
supports	O
WavPack	B-Application
out	O
of	O
the	O
box	O
.	O
</s>
<s>
Apple	B-Device
iPod	I-Device
range	O
of	O
music	O
players	O
do	O
not	O
support	O
WavPack	B-Application
out	O
of	O
the	O
box	O
,	O
but	O
can	O
through	O
open-source	B-Application
Rockbox	B-Application
firmware	O
.	O
</s>
<s>
iRiver	O
H100	O
series	O
,	O
through	O
open-source	B-Application
Rockbox	B-Application
firmware	O
.	O
</s>
<s>
iRiver	O
H300	O
series	O
,	O
through	O
open-source	B-Application
Rockbox	B-Application
firmware	O
.	O
</s>
<s>
Android	B-Application
smartphones	O
and	O
tablets	O
with	O
the	O
installation	O
of	O
third-party	O
media-player	O
software	O
.	O
</s>
<s>
ChromeOS	B-Operating_System
devices	O
using	O
media-player	O
software	O
installed	O
in	O
the	O
Linux	B-Application
subsystem	O
or	O
the	O
Android	B-Application
Play	O
Store	O
.	O
</s>
<s>
The	O
WavPack	B-Application
website	O
also	O
includes	O
a	O
plugin	O
that	O
allows	O
support	O
for	O
the	O
format	O
on	O
the	O
.	O
</s>
<s>
To	O
ensure	O
high-speed	O
operation	O
,	O
WavPack	B-Application
uses	O
a	O
predictor	O
that	O
is	O
implemented	O
entirely	O
in	O
integer	O
math	O
.	O
</s>
<s>
Instead	O
of	O
Rice	O
coding	O
,	O
a	O
special	O
data	O
encoder	O
for	O
WavPack	B-Application
is	O
used	O
.	O
</s>
<s>
Rice	O
coding	O
is	O
the	O
optimal	O
bit	O
coding	O
for	O
this	O
type	O
of	O
data	O
,	O
and	O
WavPack	B-Application
's	O
encoder	O
is	O
less	O
efficient	O
,	O
but	O
only	O
by	O
about	O
0.15bits	O
per	O
sample	O
(	O
or	O
less	O
than	O
1%	O
for	O
16-bit	O
data	O
)	O
.	O
</s>
<s>
The	O
first	O
one	O
is	O
that	O
WavPack	B-Application
's	O
encoder	O
does	O
not	O
require	O
the	O
data	O
to	O
be	O
buffered	O
ahead	O
of	O
encoding	O
;	O
instead	O
it	O
converts	O
each	O
sample	O
directly	O
to	O
bitcodes	O
.	O
</s>
<s>
This	O
coding	O
scheme	O
is	O
used	O
to	O
implement	O
the	O
"	O
lossy	O
"	O
mode	O
of	O
WavPack	B-Application
.	O
</s>
<s>
No	O
floating-point	B-Algorithm
arithmetic	I-Algorithm
is	O
used	O
in	O
WavPack	B-Application
's	O
data	O
path	O
because	O
,	O
according	O
to	O
the	O
author	O
,	O
integer	O
operations	O
are	O
less	O
susceptible	O
to	O
subtle	O
chip-to-chip	O
variations	O
that	O
could	O
corrupt	O
the	O
lossless	B-Algorithm
nature	O
of	O
the	O
compression	O
(	O
the	O
Pentium	B-Device
floating-point	I-Device
bug	I-Device
being	O
an	O
example	O
)	O
.	O
</s>
<s>
It	O
is	O
possible	O
that	O
a	O
lossless	B-Algorithm
compressor	O
that	O
used	O
floating-point	B-Algorithm
math	I-Algorithm
could	O
generate	O
different	O
output	O
when	O
running	O
on	O
that	O
faulty	O
Pentium	O
.	O
</s>
<s>
Even	O
disregarding	O
actual	O
bugs	O
,	O
floating-point	B-Algorithm
math	I-Algorithm
is	O
complicated	O
enough	O
that	O
there	O
could	O
be	O
subtle	O
differences	O
between	O
"	O
correct	O
"	O
implementations	O
that	O
could	O
cause	O
trouble	O
for	O
this	O
type	O
of	O
application	O
.	O
</s>
<s>
A	O
32-bit	O
error	O
detection	O
code	O
to	O
the	O
generated	O
streams	O
is	O
included	O
to	O
maintain	O
user	O
confidence	O
in	O
the	O
integrity	O
of	O
WavPack	B-Application
's	O
compression	O
.	O
</s>
<s>
WavPack	B-Application
source	O
code	O
is	O
portable	O
and	O
has	O
been	O
compiled	O
on	O
several	O
Unix	B-Application
and	O
Unix-like	B-Operating_System
operating	I-Operating_System
systems	I-Operating_System
(	O
Linux	B-Application
,	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
,	O
Solaris	B-Application
,	O
FreeBSD	B-Operating_System
,	O
OpenBSD	B-Operating_System
,	O
NetBSD	B-Device
,	O
Compaq	O
Tru64	B-Operating_System
,	O
UX	O
...	O
)	O
as	O
well	O
as	O
Windows	B-Application
,	O
DOS	B-Device
,	O
Palm	B-Operating_System
OS	I-Operating_System
,	O
and	O
OpenVMS	B-Operating_System
.	O
</s>
<s>
It	O
works	O
on	O
many	O
architectures	O
,	O
including	O
x86	B-Operating_System
,	O
ARM	B-Architecture
,	O
PowerPC	B-Architecture
,	O
AMD64	B-Device
,	O
IA-64	B-General_Concept
,	O
SPARC	B-Architecture
,	O
Alpha	B-Device
,	O
PA-RISC	B-Device
,	O
MIPS	B-Device
and	O
Motorola	B-Device
68k	I-Device
.	O
</s>
<s>
A	O
cut-down	O
version	O
of	O
WavPack	B-Application
was	O
developed	O
for	O
the	O
Texas	O
Instruments	O
TMS320	O
series	O
Digital	O
Signal	O
Processor	O
.	O
</s>
<s>
This	O
was	O
aimed	O
predominantly	O
at	O
encouraging	O
manufacturers	O
to	O
incorporate	O
WavPack	B-Application
compression	O
(	O
and	O
de-compression	O
)	O
into	O
portable	O
memory	O
audio	O
recorders	O
.	O
</s>
<s>
This	O
version	O
supported	O
features	O
that	O
were	O
applicable	O
only	O
to	O
embedded	O
applications	O
(	O
stream	O
compression	O
in	O
real-time	O
,	O
selectable	O
compression	O
rate	O
)	O
and	O
dropped	O
off	O
features	O
that	O
only	O
applied	O
to	O
full	O
computer	O
systems	O
(	O
self	O
extraction	O
,	O
high	O
compression	O
modes	O
,	O
32-bit	O
floats	B-Algorithm
)	O
.	O
</s>
<s>
The	O
TMS320	O
series	O
DSPs	O
are	O
native	O
integer	O
devices	O
,	O
and	O
support	O
WavPack	B-Application
well	O
.	O
</s>
<s>
Some	O
"	O
special	O
"	O
features	O
of	O
the	O
full	O
WavPack	B-Application
software	O
were	O
included	O
(	O
ability	O
to	O
generate	O
a	O
correction	O
"	O
file	O
"	O
(	O
stream	O
)	O
,	O
for	O
example	O
)	O
,	O
and	O
others	O
were	O
excluded	O
.	O
</s>
<s>
WavPack	B-Application
support	O
was	O
added	O
to	O
WinZip	B-Application
starting	O
with	O
version	O
11.0	O
beta	O
,	O
released	O
in	O
October	O
2006	O
.	O
</s>
<s>
This	O
extension	O
to	O
the	O
ZIP	B-General_Concept
file	I-General_Concept
format	I-General_Concept
was	O
included	O
by	O
PKWARE	B-Application
,	O
the	O
maintainers	O
of	O
the	O
format	O
,	O
in	O
the	O
official	O
description	O
file	O
starting	O
with	O
version	O
6.3.2	O
,	O
released	O
on	O
28September	O
2007	O
.	O
</s>
