<s>
MPEG-4	B-Algorithm
Part	I-Algorithm
3	I-Algorithm
or	O
MPEG-4	B-Algorithm
Audio	I-Algorithm
(	O
formally	O
ISO/IEC	B-Algorithm
14496-3	I-Algorithm
)	O
is	O
the	O
third	O
part	O
of	O
the	O
ISO/IEC	O
MPEG-4	B-Algorithm
international	O
standard	O
developed	O
by	O
Moving	O
Picture	O
Experts	O
Group	O
.	O
</s>
<s>
The	O
first	O
version	O
of	O
ISO/IEC	B-Algorithm
14496-3	I-Algorithm
was	O
published	O
in	O
1999	O
.	O
</s>
<s>
The	O
MPEG-4	B-Algorithm
Part	I-Algorithm
3	I-Algorithm
consists	O
of	O
a	O
variety	O
of	O
audio	O
coding	O
technologies	O
–	O
from	O
lossy	B-Algorithm
speech	B-Application
coding	I-Application
(	O
HVXC	B-Algorithm
,	O
CELP	B-Algorithm
)	O
,	O
general	O
audio	O
coding	O
(	O
AAC	B-Application
,	O
TwinVQ	B-Algorithm
,	O
BSAC	O
)	O
,	O
lossless	B-Algorithm
audio	O
compression	O
(	O
MPEG-4	B-Algorithm
SLS	O
,	O
Audio	B-Algorithm
Lossless	I-Algorithm
Coding	I-Algorithm
,	O
MPEG-4	B-Algorithm
DST	O
)	O
,	O
a	O
Text-To-Speech	B-Application
Interface	O
(	O
TTSI	O
)	O
,	O
Structured	B-Application
Audio	I-Application
(	O
using	O
SAOL	B-Language
,	O
SASL	O
,	O
MIDI	O
)	O
and	O
many	O
additional	O
audio	O
synthesis	O
and	O
coding	O
techniques	O
.	O
</s>
<s>
MPEG-4	B-Algorithm
Audio	I-Algorithm
does	O
not	O
target	O
a	O
single	O
application	O
such	O
as	O
real-time	O
telephony	O
or	O
high-quality	O
audio	O
compression	O
.	O
</s>
<s>
MPEG-4	B-Algorithm
Audio	I-Algorithm
is	O
a	O
new	O
type	O
of	O
audio	O
standard	O
that	O
integrates	O
numerous	O
different	O
types	O
of	O
audio	O
coding	O
:	O
natural	O
sound	O
and	O
synthetic	O
sound	O
,	O
low	O
bitrate	O
delivery	O
and	O
high-quality	O
delivery	O
,	O
speech	O
and	O
music	O
,	O
complex	O
soundtracks	O
and	O
simple	O
ones	O
,	O
traditional	O
content	O
and	O
interactive	O
content	O
.	O
</s>
<s>
MPEG-4	B-Algorithm
Part	I-Algorithm
3	I-Algorithm
contains	O
following	O
subparts	O
:	O
</s>
<s>
Subpart	O
1	O
:	O
Main	O
(	O
list	O
of	O
Audio	O
Object	O
Types	O
,	O
Profiles	O
,	O
Levels	O
,	O
interface	O
to	O
ISO/IEC	B-Algorithm
14496-1	I-Algorithm
,	O
MPEG-4	B-Algorithm
Audio	I-Algorithm
transport	O
stream	O
,	O
etc	O
.	O
)	O
</s>
<s>
MPEG-4	B-Algorithm
Audio	I-Algorithm
includes	O
a	O
system	O
for	O
handling	O
a	O
diverse	O
group	O
of	O
audio	O
formats	O
in	O
a	O
uniform	O
manner	O
.	O
</s>
<s>
It	O
directly	O
determines	O
the	O
MPEG-4	B-Algorithm
tool	O
subset	O
required	O
to	O
decode	O
a	O
specific	O
object	O
.	O
</s>
<s>
The	O
MPEG-4	B-Algorithm
profiles	O
are	O
based	O
on	O
the	O
object	O
types	O
and	O
each	O
profile	O
supports	O
a	O
different	O
list	O
of	O
object	O
types	O
.	O
</s>
<s>
+	O
MPEG-4	B-Algorithm
Audio	I-Algorithm
Object	O
Types	O
Object	O
Type	O
ID	O
Audio	O
Object	O
Type	O
First	O
public	O
release	O
date	O
Description	O
1	O
AAC	B-Application
Main	O
1999	O
contains	O
AAC	B-Application
LC	I-Application
2	O
AAC	B-Application
LC	I-Application
(	O
Low	O
Complexity	O
)	O
1999	O
Used	O
in	O
the	O
"	O
AAC	B-Application
Profile	O
"	O
.	O
</s>
<s>
MPEG-4	B-Application
AAC	I-Application
LC	O
Audio	O
Object	O
Type	O
is	O
based	O
on	O
the	O
MPEG-2	B-Application
Part	I-Application
7	I-Application
Low	O
Complexity	O
profile	O
(	O
LC	O
)	O
combined	O
with	O
Perceptual	O
Noise	O
Substitution	O
(	O
PNS	O
)	O
(	O
defined	O
in	O
MPEG-4	B-Algorithm
Part	I-Algorithm
3	I-Algorithm
Subpart	O
4	O
)	O
.	O
</s>
<s>
3	O
AAC	B-Application
SSR	O
(	O
Scalable	O
Sample	O
Rate	O
)	O
1999	O
MPEG-4	B-Application
AAC	I-Application
SSR	O
Audio	O
Object	O
Type	O
is	O
based	O
on	O
the	O
MPEG-2	B-Application
Part	I-Application
7	I-Application
Scalable	O
Sampling	O
Rate	O
profile	O
(	O
SSR	O
)	O
combined	O
with	O
Perceptual	O
Noise	O
Substitution	O
(	O
PNS	O
)	O
(	O
defined	O
in	O
MPEG-4	B-Algorithm
Part	I-Algorithm
3	I-Algorithm
Subpart	O
4	O
)	O
.	O
</s>
<s>
4	O
AAC	B-Application
LTP	O
(	O
Long	O
Term	O
Prediction	O
)	O
1999	O
contains	O
AAC	B-Application
LC	I-Application
5	O
SBR	O
(	O
Spectral	B-Algorithm
Band	I-Algorithm
Replication	I-Algorithm
)	O
2003	O
used	O
with	O
AAC	B-Application
LC	I-Application
in	O
the	O
"	O
High	O
Efficiency	O
AAC	B-Application
Profile	O
"	O
(	O
HE-AAC	O
v1	O
)	O
6	O
AAC	B-Application
Scalable	O
1999	O
7	O
TwinVQ	B-Algorithm
1999	O
audio	O
coding	O
at	O
very	O
low	O
bitrates	O
8	O
CELP	B-Algorithm
(	O
Code	B-Algorithm
Excited	I-Algorithm
Linear	I-Algorithm
Prediction	I-Algorithm
)	O
1999	O
speech	B-Application
coding	I-Application
9	O
HVXC	B-Algorithm
(	O
Harmonic	B-Algorithm
Vector	I-Algorithm
eXcitation	I-Algorithm
Coding	I-Algorithm
)	O
1999	O
speech	B-Application
coding	I-Application
10	O
(	O
Reserved	O
)	O
11	O
(	O
Reserved	O
)	O
12	O
TTSI	O
(	O
Text-To-Speech	B-Application
Interface	O
)	O
1999	O
13	O
Main	O
synthesis	O
1999	O
contains	O
'	O
wavetable	O
 '	O
sample-based	O
synthesis	O
and	O
Algorithmic	O
Synthesis	O
and	O
Audio	O
Effects	O
14	O
'	O
wavetable	O
 '	O
sample-based	O
synthesis	O
1999	O
based	O
on	O
SoundFont	B-Application
and	O
DownLoadable	O
Sounds	O
,	O
contains	O
General	O
MIDI	O
15	O
General	O
MIDI	O
1999	O
16	O
Algorithmic	O
Synthesis	O
and	O
Audio	O
Effects	O
1999	O
17	O
ER	O
AAC	B-Application
LC	I-Application
2000	O
Error	O
Resilient	O
18	O
(	O
Reserved	O
)	O
19	O
ER	O
AAC	B-Application
LTP	O
2000	O
Error	O
Resilient	O
20	O
ER	O
AAC	B-Application
Scalable	O
2000	O
Error	O
Resilient	O
21	O
ER	O
TwinVQ	B-Algorithm
2000	O
Error	O
Resilient	O
22	O
ER	O
BSAC	O
(	O
Bit-Sliced	O
Arithmetic	O
Coding	O
)	O
2000	O
It	O
is	O
also	O
known	O
as	O
"	O
Fine	O
Granule	O
Audio	O
"	O
or	O
fine	O
grain	O
scalability	O
tool	O
.	O
</s>
<s>
It	O
is	O
used	O
in	O
combination	O
with	O
the	O
AAC	B-Application
coding	O
tools	O
and	O
replaces	O
the	O
noiseless	O
coding	O
and	O
the	O
bitstream	O
formatting	O
of	O
MPEG-4	B-Algorithm
Version	O
1	O
GA	O
coder	O
.	O
</s>
<s>
Error	O
Resilient	O
23	O
ER	O
AAC	B-Algorithm
LD	I-Algorithm
(	O
Low	O
Delay	O
)	O
2000	O
Error	O
Resilient	O
,	O
used	O
with	O
CELP	B-Algorithm
,	O
ER	O
CELP	B-Algorithm
,	O
HVXC	B-Algorithm
,	O
ER	O
HVXC	B-Algorithm
and	O
TTSI	O
in	O
the	O
"	O
Low	O
Delay	O
Profile	O
"	O
,	O
(	O
commonly	O
used	O
for	O
real-time	O
conversation	O
applications	O
)	O
24	O
ER	O
CELP	B-Algorithm
2000	O
Error	O
Resilient	O
25	O
ER	O
HVXC	B-Algorithm
2000	O
Error	O
Resilient	O
26	O
ER	O
HILN	B-Algorithm
(	O
Harmonic	O
and	O
Individual	O
Lines	O
plus	O
Noise	O
)	O
2000	O
Error	O
Resilient	O
27	O
ER	O
Parametric	O
2000	O
Error	O
Resilient	O
28	O
SSC	O
(	O
SinuSoidal	O
Coding	O
)	O
2004	O
29	O
PS	O
(	O
Parametric	O
Stereo	O
)	O
2004	O
and	O
2006	O
used	O
with	O
AAC	B-Application
LC	I-Application
and	O
SBR	O
in	O
the	O
"	O
HE-AAC	O
v2	O
Profile	O
"	O
.	O
</s>
<s>
30	O
MPEG	O
Surround	O
2007	O
also	O
known	O
as	O
MPEG	O
Spatial	O
Audio	O
Coding	O
(	O
SAC	O
)	O
,	O
it	O
is	O
a	O
type	O
of	O
spatial	O
audio	O
coding	O
(	O
MPEG	O
Surround	O
was	O
also	O
defined	O
in	O
ISO/IEC	O
23003-1	O
in	O
2007	O
)	O
31	O
(	O
ESCAPE	O
)	O
32	O
MPEG-1/2	O
Layer-1	O
2005	O
33	O
MPEG-1/2	O
Layer-2	O
2005	O
34	O
MPEG-1/2	B-Application
Layer-3	I-Application
2005	O
also	O
known	O
as	O
"	O
MP3onMP4	O
"	O
35	O
DST	O
(	O
Direct	O
Stream	O
Transfer	O
)	O
2005	O
lossless	B-Algorithm
audio	O
coding	O
,	O
used	O
on	O
Super	O
Audio	O
CD	O
36	O
ALS	O
(	O
Audio	B-Algorithm
Lossless	I-Algorithm
Coding	I-Algorithm
)	O
2006	O
lossless	B-Algorithm
audio	O
coding	O
37	O
SLS	O
(	O
Scalable	O
Lossless	B-Algorithm
Coding	O
)	O
2006	O
two-layer	O
audio	O
coding	O
with	O
lossless	B-Algorithm
layer	O
and	O
lossy	B-Algorithm
General	O
Audio	O
core/layer	O
(	O
e.g.	O
</s>
<s>
AAC	B-Application
)	O
38	O
SLS	O
non-core	O
2006	O
lossless	B-Algorithm
audio	O
coding	O
without	O
lossy	B-Algorithm
General	O
Audio	O
core/layer	O
(	O
e.g.	O
</s>
<s>
AAC	B-Application
)	O
39	O
ER	O
AAC	B-Application
ELD	O
(	O
Enhanced	O
Low	O
Delay	O
)	O
2008	O
Error	O
Resilient	O
40	O
SMR	O
(	O
Symbolic	O
Music	O
Representation	O
)	O
Simple	O
2008	O
note	O
:	O
Symbolic	O
Music	O
Representation	O
is	O
also	O
the	O
MPEG-4	B-Algorithm
Part	I-Algorithm
23	I-Algorithm
standard	O
(	O
ISO/IEC	O
14496-23:2008	O
)	O
41	O
SMR	O
Main	O
2008	O
42	O
USAC	O
(	O
Unified	O
Speech	O
and	O
Audio	O
Coding	O
)	O
2012	O
Unified	O
Speech	O
and	O
audio	O
Coding	O
is	O
defined	O
in	O
MPEG-D	O
Part	O
3	O
(	O
ISO/IEC	O
23003-3:2012	O
)	O
43	O
SAOC	O
(	O
Spatial	O
Audio	O
Object	O
Coding	O
)	O
2010	O
note	O
:	O
Spatial	O
Audio	O
Object	O
Coding	O
is	O
also	O
the	O
MPEG-D	O
Part	O
2	O
standard	O
(	O
ISO/IEC	O
23003-2:2010	O
)	O
44	O
LD	O
MPEG	O
Surround	O
2010	O
This	O
object	O
type	O
conveys	O
Low	O
Delay	O
MPEG	O
Surround	O
Coding	O
side	O
information	O
(	O
that	O
was	O
defined	O
in	O
MPEG-D	O
Part	O
2	O
–	O
ISO/IEC	O
23003-2	O
)	O
in	O
the	O
MPEG-4	B-Algorithm
Audio	I-Algorithm
framework	O
.	O
</s>
<s>
The	O
MPEG-4	B-Algorithm
Audio	I-Algorithm
standard	O
defines	O
several	O
profiles	O
.	O
</s>
<s>
There	O
is	O
no	O
standard	O
for	O
transport	O
of	O
elementary	O
streams	O
over	O
a	O
channel	O
,	O
because	O
the	O
broad	O
range	O
of	O
MPEG-4	B-Algorithm
applications	O
have	O
delivery	O
requirements	O
that	O
are	O
too	O
wide	O
to	O
easily	O
characterize	O
with	O
a	O
single	O
solution	O
.	O
</s>
<s>
A	O
wide	O
variety	O
of	O
delivery	O
mechanisms	O
exist	O
below	O
this	O
interface	O
,	O
e.g.	O
,	O
MPEG	O
transport	O
stream	O
,	O
Real-time	B-Protocol
Transport	I-Protocol
Protocol	I-Protocol
(	O
RTP	O
)	O
,	O
etc	O
.	O
</s>
<s>
Transport	O
in	O
Real-time	B-Protocol
Transport	I-Protocol
Protocol	I-Protocol
is	O
defined	O
in	O
RFC	O
3016	O
(	O
RTP	O
Payload	O
Format	O
for	O
MPEG-4	B-Algorithm
Audio/Visual	O
Streams	O
)	O
,	O
RFC	O
3640	O
(	O
RTP	O
Payload	O
Format	O
for	O
Transport	O
of	O
MPEG-4	B-Algorithm
Elementary	O
Streams	O
)	O
,	O
RFC	O
4281	O
(	O
The	O
Codecs	O
Parameter	O
for	O
"	O
Bucket	O
"	O
Media	O
Types	O
)	O
and	O
RFC	O
4337	O
(	O
MIME	O
Type	O
Registration	O
for	O
MPEG-4	B-Algorithm
)	O
.	O
</s>
<s>
LATM	O
and	O
LOAS	O
were	O
defined	O
for	O
natural	O
audio	O
applications	O
,	O
which	O
do	O
not	O
require	O
sophisticated	O
object-based	O
coding	O
or	O
other	O
functions	O
provided	O
by	O
MPEG-4	B-Algorithm
Systems	O
.	O
</s>
<s>
The	O
Advanced	B-Application
Audio	I-Application
Coding	I-Application
in	O
MPEG-4	B-Algorithm
Part	I-Algorithm
3	I-Algorithm
(	O
MPEG-4	B-Algorithm
Audio	I-Algorithm
)	O
Subpart	O
4	O
was	O
enhanced	O
relative	O
to	O
the	O
previous	O
standard	O
MPEG-2	B-Application
Part	I-Application
7	I-Application
(	O
Advanced	B-Application
Audio	I-Application
Coding	I-Application
)	O
,	O
in	O
order	O
to	O
provide	O
better	O
sound	O
quality	O
for	O
a	O
given	O
encoding	O
bitrate	O
.	O
</s>
<s>
The	O
MPEG-2	B-Application
Part	I-Application
7	I-Application
standard	O
(	O
Advanced	B-Application
Audio	I-Application
Coding	I-Application
)	O
was	O
first	O
published	O
in	O
1997	O
and	O
offers	O
three	O
default	O
profiles	O
:	O
Low	O
Complexity	O
profile	O
(	O
LC	O
)	O
,	O
Main	O
profile	O
and	O
Scalable	O
Sampling	O
Rate	O
profile	O
(	O
SSR	O
)	O
.	O
</s>
<s>
The	O
MPEG-4	B-Algorithm
Part	I-Algorithm
3	I-Algorithm
Subpart	O
4	O
(	O
General	O
Audio	O
Coding	O
)	O
combined	O
the	O
profiles	O
from	O
MPEG-2	B-Application
Part	I-Application
7	I-Application
with	O
Perceptual	O
Noise	O
Substitution	O
(	O
PNS	O
)	O
and	O
defined	O
them	O
as	O
Audio	O
Object	O
Types	O
(	O
AAC	B-Application
LC	I-Application
,	O
AAC	B-Application
Main	O
,	O
AAC	B-Application
SSR	O
)	O
.	O
</s>
<s>
High-Efficiency	O
Advanced	B-Application
Audio	I-Application
Coding	I-Application
is	O
an	O
extension	O
of	O
AAC	B-Application
LC	I-Application
using	O
spectral	B-Algorithm
band	I-Algorithm
replication	I-Algorithm
(	O
SBR	O
)	O
,	O
and	O
Parametric	O
Stereo	O
(	O
PS	O
)	O
.	O
</s>
<s>
AAC	B-Application
Scalable	O
Sample	O
Rate	O
was	O
introduced	O
by	O
Sony	O
to	O
the	O
MPEG-2	B-Application
Part	I-Application
7	I-Application
and	O
MPEG-4	B-Algorithm
Part	I-Algorithm
3	I-Algorithm
standards	O
.	O
</s>
<s>
It	O
was	O
first	O
published	O
in	O
ISO/IEC	B-Algorithm
13818-7	I-Algorithm
,	O
Part	O
7	O
:	O
Advanced	B-Application
Audio	I-Application
Coding	I-Application
(	O
AAC	B-Application
)	O
in	O
1997	O
.	O
</s>
<s>
This	O
is	O
similar	O
to	O
normal	O
AAC	B-Application
LC	I-Application
which	O
uses	O
MDCTs	O
with	O
a	O
size	O
k	O
of	O
128	O
or	O
1024	O
directly	O
on	O
the	O
audio	O
signal	O
.	O
</s>
<s>
However	O
,	O
due	O
to	O
aliasing	O
between	O
the	O
4	O
PQF	O
bands	O
coding	O
efficiencies	O
around	O
(	O
1	O
,	O
2	O
,	O
3	O
)	O
*	O
fs/8	O
is	O
worse	O
than	O
normal	O
MPEG-4	B-Application
AAC	I-Application
LC	O
.	O
</s>
<s>
The	O
idea	O
behind	O
AAC-SSR	O
was	O
not	O
only	O
the	O
advantage	O
listed	O
above	O
,	O
but	O
also	O
the	O
possibility	O
of	O
reducing	O
the	O
data	O
rate	O
by	O
removing	O
1	O
,	O
2	O
or	O
3	O
of	O
the	O
upper	O
PQF	O
bands	O
.	O
</s>
<s>
Bit	O
Sliced	O
Arithmetic	O
Coding	O
is	O
an	O
MPEG-4	B-Algorithm
standard	O
(	O
ISO/IEC	B-Algorithm
14496-3	I-Algorithm
subpart	O
4	O
)	O
for	O
scalable	O
audio	O
coding	O
.	O
</s>
<s>
BSAC	O
uses	O
an	O
alternative	O
noiseless	O
coding	O
to	O
AAC	B-Application
,	O
with	O
the	O
rest	O
of	O
the	O
processing	O
being	O
identical	O
to	O
AAC	B-Application
.	O
</s>
<s>
This	O
support	O
for	O
scalability	O
allows	O
for	O
nearly	O
transparent	O
sound	O
quality	O
at	O
64kbit/s	O
and	O
graceful	B-General_Concept
degradation	I-General_Concept
at	O
lower	O
bit	O
rates	O
.	O
</s>
<s>
The	O
AAC-BSAC	O
codec	O
is	O
used	O
in	O
Digital	O
Multimedia	O
Broadcasting	O
(	O
DMB	O
)	O
applications	O
.	O
</s>
<s>
In	O
2002	O
,	O
the	O
MPEG-4	B-Algorithm
Audio	I-Algorithm
Licensing	O
Committee	O
selected	O
the	O
Via	O
Licensing	O
Corporation	O
as	O
the	O
Licensing	O
Administrator	O
for	O
the	O
MPEG-4	B-Algorithm
Audio	I-Algorithm
patent	O
pool	O
.	O
</s>
