<s>
Digital	O
storage	O
media	O
command	O
and	O
control	O
(	O
DSM-CC	B-Algorithm
)	O
is	O
a	O
toolkit	O
for	O
developing	O
control	O
channels	O
associated	O
with	O
MPEG-1	B-Algorithm
and	O
MPEG-2	B-Algorithm
streams	O
.	O
</s>
<s>
It	O
is	O
defined	O
in	O
part	O
6	O
of	O
the	O
MPEG-2	B-Algorithm
standard	O
(	O
Extensions	O
for	O
DSM-CC	B-Algorithm
)	O
and	O
uses	O
a	O
client/server	O
model	O
connected	O
via	O
an	O
underlying	O
network	O
(	O
carried	O
via	O
the	O
MPEG-2	B-Algorithm
multiplex	B-Architecture
or	O
independently	O
if	O
needed	O
)	O
.	O
</s>
<s>
DSM-CC	B-Algorithm
may	O
be	O
used	O
for	O
controlling	O
the	O
video	O
reception	O
,	O
providing	O
features	O
normally	O
found	O
on	O
Video	O
Cassette	O
Recorders	O
(	O
VCR	O
)	O
(	O
fast-forward	O
,	O
rewind	O
,	O
pause	O
,	O
etc	O
.	O
)	O
.	O
</s>
<s>
It	O
is	O
defined	O
by	O
a	O
series	O
of	O
weighty	O
standards	O
,	O
principally	O
MPEG-2	B-Algorithm
ISO/IEC	B-Algorithm
13818-6	I-Algorithm
(	O
part	O
6	O
of	O
the	O
MPEG-2	B-Algorithm
standard	O
)	O
.	O
</s>
<s>
DSM-CC	B-Algorithm
may	O
work	O
in	O
conjunction	O
with	O
next	O
generation	O
packet	O
networks	O
,	O
working	O
alongside	O
such	O
internet	O
protocols	O
as	O
RSVP	B-Protocol
,	O
RTSP	B-Protocol
,	O
RTP	B-Protocol
and	O
SCP	B-Protocol
.	O
</s>
<s>
Although	O
DSM-CC	B-Algorithm
is	O
usually	O
associated	O
with	O
video	O
delivery	O
(	O
via	O
satellite	B-Application
or	O
terrestrially	O
)	O
and	O
with	O
interactive	B-General_Concept
content	O
,	O
it	O
is	O
also	O
used	O
among	O
audio	O
servers	O
and	O
clients	O
.	O
</s>
<s>
The	O
architecture	O
describes	O
three	O
main	O
parts	O
of	O
the	O
system	O
:	O
the	O
client	B-Protocol
,	O
the	O
server	B-Application
,	O
and	O
the	O
session	O
resource	O
manager	O
(	O
SRM	O
)	O
.	O
</s>
<s>
The	O
server	B-Application
provides	O
content	O
and	O
other	O
services	O
to	O
the	O
client	B-Protocol
,	O
and	O
both	O
are	O
"	O
clients	O
"	O
of	O
the	O
SRM	O
.	O
</s>
<s>
By	O
combining	O
server	B-Application
and	O
client	B-Protocol
components	O
together	O
onto	O
the	O
same	O
platforms	O
,	O
peer-to-peer	O
content	O
access	O
and	O
delivery	O
systems	O
can	O
be	O
constructed	O
.	O
</s>
<s>
For	O
example	O
,	O
MPEG-2	B-Algorithm
video	O
can	O
be	O
encoded	O
in	O
different	O
ways	O
,	O
and	O
a	O
DSM-CC	B-Algorithm
system	O
can	O
be	O
constructed	O
to	O
include	O
or	O
exclude	O
certain	O
features	O
and	O
interfaces	O
.	O
</s>
<s>
DSM-CC	B-Algorithm
defines	O
or	O
extends	O
five	O
distinct	O
protocols	O
:	O
</s>
<s>
User-User	O
Allows	O
remote	O
access	O
by	O
the	O
client	B-Protocol
to	O
objects	O
on	O
the	O
server	B-Application
.	O
</s>
<s>
The	O
User-User	O
specification	O
goes	O
beyond	O
the	O
definition	O
of	O
specific	O
server	B-Application
object	O
classes	O
to	O
define	O
classes	O
local	O
to	O
the	O
client	B-Protocol
,	O
as	O
well	O
as	O
some	O
of	O
the	O
interaction	O
with	O
other	O
parts	O
of	O
the	O
system	O
.	O
</s>
<s>
The	O
distributed	O
object	O
model	O
is	O
based	O
on	O
CORBA	B-Architecture
.	O
</s>
<s>
Objects	O
are	O
accessed	O
using	O
the	O
internet	B-Operating_System
inter-ORB	I-Operating_System
protocol	I-Operating_System
(	O
IIOP	B-Operating_System
)	O
,	O
with	O
some	O
optional	O
extensions	O
.	O
</s>
<s>
In	O
the	O
model	O
,	O
some	O
clients	O
may	O
also	O
load	O
content	O
onto	O
the	O
server	B-Application
.	O
</s>
<s>
This	O
protocol	O
is	O
used	O
between	O
the	O
client	B-Protocol
and	O
SRM	O
,	O
and	O
between	O
the	O
server	B-Application
and	O
SRM	O
.	O
</s>
<s>
MPEG	O
transport	O
profiles	O
The	O
specification	O
provides	O
profiles	O
to	O
the	O
standard	O
MPEG	O
transport	O
protocol	O
(	O
defined	O
by	O
ISO/IEC	B-Algorithm
13818-1	I-Algorithm
)	O
to	O
allow	O
transmission	O
of	O
event	O
,	O
synchronization	O
,	O
download	O
,	O
and	O
other	O
information	O
in	O
the	O
MPEG	O
transport	O
stream	O
.	O
</s>
<s>
Download	O
Several	O
variations	O
of	O
this	O
protocol	O
allow	O
transfer	O
of	O
content	O
from	O
server	B-Application
to	O
client	B-Protocol
,	O
either	O
within	O
the	O
MPEG	O
transport	O
stream	O
or	O
on	O
a	O
separate	O
(	O
presumably	O
high-speed	O
)	O
channel	O
.	O
</s>
<s>
Flow-controlled	O
download	O
allows	O
the	O
download	O
operations	O
to	O
be	O
negotiated	O
and	O
controlled	O
by	O
the	O
client	B-Protocol
.	O
</s>
<s>
A	O
variation	O
of	O
download	O
is	O
an	O
autonomous	O
"	O
data	B-Device
carousel	I-Device
"	O
on	O
the	O
server	B-Application
which	O
repeatedly	O
downloads	O
information	O
;	O
the	O
download	O
carousel	O
client	B-Protocol
waits	O
for	O
the	O
information	O
without	O
initiating	O
the	O
transfer	O
.	O
</s>
<s>
An	O
extension	O
to	O
the	O
data	B-Device
carousel	I-Device
is	O
the	O
"	O
object	B-Device
carousel	I-Device
"	O
,	O
which	O
presents	O
downloaded	O
information	O
as	O
objects	O
compatible	O
with	O
the	O
objects	O
defined	O
by	O
the	O
User-User	O
API	O
.	O
</s>
<s>
(	O
The	O
choice	O
of	O
download	O
or	O
IIOP	B-Operating_System
protocols	O
is	O
embedded	O
in	O
the	O
object	O
's	O
IOR	O
,	O
so	O
the	O
means	O
of	O
access	O
is	O
transparent	O
to	O
the	O
client	B-Protocol
application	I-Protocol
.	O
)	O
</s>
<s>
Switched	O
Digital	O
Broadcast-Channel	O
Change	O
Protocol	O
(	O
SDB/CCP	O
)	O
Enables	O
a	O
client	B-Protocol
to	O
remotely	O
switch	O
from	O
channel	O
to	O
channel	O
in	O
a	O
broadcast	B-Operating_System
environment	O
.	O
</s>
<s>
Used	O
to	O
attach	O
a	O
client	B-Protocol
to	O
a	O
continuous-feed	O
session	O
(	O
CFS	O
)	O
or	O
other	O
broadcast	B-Operating_System
feed	O
.	O
</s>
<s>
Delivery	O
Multimedia	O
Integration	O
Framework	O
(	O
DMIF	O
)	O
expands	O
upon	O
the	O
MPEG-2	B-Algorithm
DSM-CC	B-Algorithm
standard	O
(	O
ISO/IEC	O
13818-6:1998	O
)	O
to	O
enable	O
the	O
convergence	O
of	O
interactive	B-General_Concept
,	O
broadcast	B-Operating_System
and	O
conversational	O
multimedia	O
into	O
one	O
specification	O
which	O
will	O
be	O
applicable	O
to	O
set	O
tops	O
,	O
desktops	O
and	O
mobile	O
stations	O
.	O
</s>
<s>
The	O
DSM-CC	B-Algorithm
work	O
was	O
extended	O
as	O
part	O
of	O
the	O
ISO/IEC	O
14496-6	O
(	O
MPEG-4	B-Algorithm
Part	O
6	O
)	O
,	O
with	O
the	O
DSM-CC	B-Algorithm
Multimedia	O
Integration	O
Framework	O
(	O
DMIF	O
)	O
.	O
</s>
