<s>
Dirac	B-Application
is	O
an	O
open	O
and	O
royalty-free	O
video	B-Algorithm
compression	I-Algorithm
format	I-Algorithm
,	O
specification	O
and	O
system	O
developed	O
by	O
BBC	B-Application
Research	I-Application
&	I-Application
Development	I-Application
.	O
</s>
<s>
Schrödinger	O
and	O
dirac-research	O
(	O
formerly	O
just	O
called	O
"	O
Dirac	B-Application
"	O
)	O
are	O
open	O
and	O
royalty-free	O
software	O
implementations	O
(	O
video	B-Application
codecs	I-Application
)	O
of	O
Dirac	B-Application
.	O
</s>
<s>
Dirac	B-Application
format	O
aims	O
to	O
provide	O
high-quality	O
video	O
compression	O
for	O
Ultra	B-Device
HDTV	I-Device
and	O
beyond	O
,	O
and	O
as	O
such	O
competes	O
with	O
existing	O
formats	O
such	O
as	O
H.264	B-Application
and	O
VC-1	B-Operating_System
.	O
</s>
<s>
In	O
September	O
of	O
that	O
year	O
,	O
version	O
1.0.0	O
of	O
an	O
I-frame	B-General_Concept
only	O
subset	O
known	O
as	O
Dirac	B-Application
Pro	O
was	O
released	O
and	O
has	O
since	O
been	O
standardised	O
by	O
the	O
SMPTE	O
as	O
VC-2	B-Application
.	O
</s>
<s>
Version	O
2.2.3	O
of	O
the	O
full	O
Dirac	B-Application
specification	O
,	O
including	O
motion	B-Algorithm
compensation	I-Algorithm
and	O
inter-frame	O
coding	O
,	O
was	O
issued	O
a	O
few	O
days	O
later	O
.	O
</s>
<s>
Dirac	B-Application
Pro	O
was	O
used	O
internally	O
by	O
the	O
BBC	O
to	O
transmit	O
HDTV	B-Device
pictures	O
at	O
the	O
Beijing	O
Olympics	O
in	O
2008	O
.	O
</s>
<s>
The	O
format	O
implementations	O
are	O
named	O
in	O
honour	O
of	O
the	O
theoretical	O
physicists	O
Paul	O
Dirac	B-Application
and	O
Erwin	O
Schrödinger	O
,	O
who	O
shared	O
the	O
1933	O
Nobel	O
Prize	O
in	O
physics	O
.	O
</s>
<s>
Dirac	B-Application
supports	O
resolutions	O
of	O
HDTV	B-Device
(	O
1920×1080	O
)	O
and	O
greater	O
,	O
and	O
is	O
claimed	O
to	O
provide	O
significant	O
savings	O
in	O
data	O
rate	O
and	O
improvements	O
in	O
quality	O
over	O
video	B-Algorithm
compression	I-Algorithm
formats	I-Algorithm
such	O
as	O
MPEG-2	B-Algorithm
Part	I-Algorithm
2	I-Algorithm
,	O
MPEG-4	B-Application
Part	I-Application
2	I-Application
and	O
its	O
competitors	O
,	O
e.g.	O
</s>
<s>
Theora	B-Algorithm
,	O
and	O
WMV	B-Device
.	O
</s>
<s>
Dirac	B-Application
's	O
implementers	O
make	O
the	O
preliminary	O
claim	O
of	O
"	O
a	O
two-fold	O
reduction	O
in	O
bit	O
rate	O
over	O
MPEG-2	O
for	O
high	O
definition	O
video	O
"	O
,	O
which	O
makes	O
it	O
comparable	O
to	O
standards	O
such	O
as	O
H.264/MPEG	B-Application
-4	I-Application
AVC	I-Application
and	O
VC-1	B-Operating_System
.	O
</s>
<s>
Dirac	B-Application
supports	O
both	O
constant	B-General_Concept
bit	I-General_Concept
rate	I-General_Concept
and	O
variable	B-General_Concept
bit	I-General_Concept
rate	I-General_Concept
operation	O
.	O
</s>
<s>
When	O
the	O
low	O
delay	O
syntax	O
is	O
used	O
,	O
the	O
bit	O
rate	O
will	O
be	O
constant	O
for	O
each	O
area	O
(	O
Dirac	B-Application
slice	O
)	O
in	O
a	O
picture	O
to	O
ensure	O
constant	O
latency	O
.	O
</s>
<s>
Dirac	B-Application
supports	O
lossy	B-Algorithm
and	O
lossless	B-Algorithm
compression	I-Algorithm
modes	O
.	O
</s>
<s>
Dirac	B-Application
employs	O
wavelet	O
compression	O
,	O
like	O
the	O
JPEG	O
2000	O
and	O
PGF	O
image	O
formats	O
and	O
the	O
Cineform	B-Algorithm
professional	O
video	B-Application
codec	I-Application
,	O
instead	O
of	O
the	O
discrete	B-General_Concept
cosine	I-General_Concept
transforms	I-General_Concept
used	O
in	O
MPEG	O
compression	O
formats	O
.	O
</s>
<s>
Two	O
of	O
the	O
specific	O
wavelets	O
Dirac	B-Application
can	O
use	O
are	O
nearly	O
identical	O
to	O
JPEG	O
2000	O
's	O
(	O
known	O
as	O
the	O
5/3	O
and	O
9/7	O
wavelets	O
)	O
,	O
as	O
well	O
as	O
two	O
more	O
derived	O
from	O
them	O
.	O
</s>
<s>
Dirac	B-Application
can	O
be	O
used	O
in	O
AVI	O
,	O
Ogg	O
and	O
Matroska	O
container	O
formats	O
and	O
is	O
also	O
registered	O
for	O
use	O
in	O
the	O
MPEG-4	O
file	O
format	O
and	O
MPEG-2	O
transport	O
streams	O
.	O
</s>
<s>
Dirac	B-Application
Pro	O
was	O
proposed	O
to	O
the	O
SMPTE	O
for	O
standardisation	O
.	O
</s>
<s>
The	O
Dirac	B-Application
Pro	O
specification	O
defines	O
an	O
I-frame	B-General_Concept
only	O
subset	O
of	O
the	O
main	O
Dirac	B-Application
Specification	O
,	O
aimed	O
for	O
professional	O
and	O
studio	O
use	O
in	O
high	O
bitrate	O
applications	O
.	O
</s>
<s>
In	O
2010	O
,	O
the	O
SMPTE	O
standardised	O
Dirac	B-Application
Pro	O
as	O
VC-2	B-Application
.	O
</s>
<s>
The	O
basic	O
spec	O
was	O
updated	O
in	O
2012	O
,	O
adding	O
a	O
new	O
profile	O
for	O
lossless	B-Algorithm
and	O
near-lossless	O
archiving	O
.	O
</s>
<s>
The	O
first	O
is	O
the	O
BBC	O
's	O
reference	O
implementation	O
,	O
formerly	O
just	O
called	O
Dirac	B-Application
but	O
renamed	O
dirac-research	O
to	O
avoid	O
confusion	O
.	O
</s>
<s>
It	O
is	O
written	O
in	O
C++	O
and	O
released	O
under	O
the	O
Mozilla	B-License
Public	I-License
License	I-License
,	O
GNU	B-License
GPL	I-License
2	O
and	O
GNU	B-Application
LGPL	I-Application
free	B-License
software	I-License
licenses	I-License
.	O
</s>
<s>
Schrödinger	O
is	O
written	O
in	O
ANSI	O
C	B-Language
and	O
released	O
under	O
the	O
same	O
licenses	O
as	O
dirac-research	O
,	O
as	O
well	O
as	O
the	O
highly-permissive	O
MIT	B-License
License	I-License
.	O
</s>
<s>
The	O
Schrödinger	O
project	O
also	O
provides	O
GStreamer	B-Language
plugins	O
to	O
enable	O
the	O
library	O
to	O
be	O
used	O
with	O
that	O
framework	O
.	O
</s>
<s>
As	O
of	O
the	O
release	O
of	O
Schrödinger-1.0.9	O
,	O
"	O
Schrödinger	O
outperforms	O
dirac-research	O
in	O
most	O
encoding	O
situations	O
,	O
both	O
in	O
terms	O
of	O
encoding	O
speed	O
and	O
visual	O
quality	O
"	O
.	O
</s>
<s>
With	O
that	O
release	O
,	O
most	O
of	O
the	O
encoding	O
tools	O
in	O
dirac-research	O
have	O
been	O
ported	O
over	O
to	O
Schrödinger	O
,	O
giving	O
Schrödinger	O
the	O
same	O
as	O
or	O
better	O
compression	O
efficiency	O
than	O
dirac-research	O
.	O
</s>
<s>
The	O
BBC	O
does	O
not	O
own	O
any	O
patents	O
on	O
Dirac	B-Application
.	O
</s>
<s>
They	O
previously	O
had	O
some	O
patent	O
applications	O
with	O
plans	O
to	O
irrevocably	O
grant	O
a	O
royalty-free	O
licence	O
for	O
their	O
Dirac-related	O
patents	O
to	O
everyone	O
,	O
but	O
they	O
let	O
the	O
applications	O
lapse	O
.	O
</s>
<s>
In	O
addition	O
,	O
the	O
developers	O
have	O
said	O
they	O
will	O
try	O
to	O
ensure	O
that	O
Dirac	B-Application
does	O
not	O
infringe	O
on	O
any	O
third	O
party	O
patents	O
,	O
enabling	O
the	O
public	O
to	O
use	O
Dirac	B-Application
for	O
any	O
purpose	O
.	O
</s>
<s>
As	O
of	O
November	O
2008	O
,	O
Dirac	B-Application
video	O
playback	O
is	O
supported	O
by	O
VLC	B-Application
media	I-Application
player	I-Application
(	O
version	O
0.9.2	O
or	O
newer	O
)	O
,	O
and	O
by	O
applications	O
using	O
the	O
GStreamer	B-Language
framework	O
(	O
such	O
as	O
Songbird	B-Application
,	O
Rhythmbox	B-Language
and	O
Totem	B-Language
)	O
.	O
</s>
<s>
Support	O
has	O
also	O
been	O
added	O
to	O
FFmpeg	B-Library
.	O
</s>
<s>
Applications	O
which	O
can	O
encode	O
to	O
Dirac	B-Application
include	O
MediaCoder	B-Algorithm
,	O
LiVES	O
and	O
OggConvert	B-Language
,	O
as	O
well	O
as	O
FFmpeg	B-Library
.	O
</s>
<s>
The	O
algorithms	O
in	O
the	O
Dirac	B-Application
specification	O
have	O
been	O
designed	O
with	O
the	O
intention	O
to	O
provide	O
a	O
competitive	O
performance	O
as	O
compared	O
to	O
state-of-the-art	O
international	O
standards	O
.	O
</s>
<s>
Whether	O
they	O
succeeded	O
is	O
an	O
open	O
question	O
;	O
while	O
at	O
least	O
one	O
comparison	O
exists	O
which	O
used	O
implementations	O
from	O
the	O
second	O
quarter	O
of	O
2008	O
—	O
it	O
shows	O
x264	B-Language
scoring	O
higher	O
than	O
Dirac	B-Application
—	O
it	O
is	O
now	O
somewhat	O
out	O
of	O
date	O
.	O
</s>
<s>
A	O
study	O
on	O
the	O
performances	O
of	O
the	O
Dirac	B-Application
codec	I-Application
,	O
dated	O
from	O
August	O
2009	O
,	O
finds	O
that	O
the	O
quality	O
obtained	O
on	O
SDTV	O
is	O
inferior	O
to	O
the	O
H.264	B-Application
output	O
and	O
did	O
not	O
include	O
HD	O
content	O
.	O
</s>
