ISO/IEC 14496-3:1999/Amd 1:2000/Cor 1:2001
(Corrigendum)Information technology — Coding of audio-visual objects — Part 3: Audio — Amendment 1: Audio extensions — Technical Corrigendum 1
Information technology — Coding of audio-visual objects — Part 3: Audio — Amendment 1: Audio extensions — Technical Corrigendum 1
Technologies de l'information — Codage des objets audiovisuels — Partie 3: Codage audio — Amendement 1: Extensions audio — Rectificatif technique 1
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Standards Content (Sample)
INTERNATIONAL STANDARD ISO/IEC 14496-3:1999/Amd.1:2000
TECHNICAL CORRIGENDUM 1
Published 2001-08-01
INTERNATIONAL ORGANIZATION FOR STANDARDIZATION • МЕЖДУНАРОДНАЯ ОРГАНИЗАЦИЯ ПО СТАНДАРТИЗАЦИИ • ORGANISATION INTERNATIONALE DE NORMALISATION
INTERNATIONAL ELECTROTECHNICAL COMMISSION • МЕЖДУНАРОДНАЯ ЭЛЕКТРОТЕХНИЧЕСКАЯ КОМИССИЯ • COMMISSION ÉLECTROTECHNIQUE INTERNATIONALE
Information technology — Coding of audio-visual objects —
Part 3:
Audio
AMENDMENT 1: Audio extensions
TECHNICAL CORRIGENDUM 1
Technologies de l'information — Codage des objets audiovisuels —
Partie 3: Codage audio
AMENDEMENT 1: Extensions audio
RECTIFICATIF TECHNIQUE 1
Technical Corrigendum 1 to International Standard ISO/IEC 14496-3:1999/Amd.1:2000 was prepared by Joint
Technical Committee ISO/IEC JTC 1, Information technology, Subcommittee SC 29, Coding of audio, picture,
multimedia and hypermedia information.
ICS 35.040 Ref. No. ISO/IEC 14496-3:1999/Amd.1:2000/Cor.1:2001(E)
© ISO/IEC 2001 – All rights reserved
Printed in Switzerland
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ISO/IEC 14496-3:1999/Amd.1:2000/Cor.1:2001(E)
Throughout the text of ISO/IEC 14496-3:1999/Amd.1:2000, replace all occurrences of “AL PDU” with “SL packet” and all
occurrences of “alPduPayload” with “slPacketPayload”.
In clause “Introduction”, add
"
"MPEG-4 has no standard for transport. In all of the MPEG-4 tools for audio and visual coding, the coding
standard ends at the point of constructing a sequence of access units that contain the compressed data. The
MPEG-4 Systems (ISO/IEC 14496-1:2001) specification describes how to convert the individually coded objects into
a bitstream that contains a number of multiplexed sub-streams.
There is no standard mechanism for transport of this stream over a channel; this is because the broad range of
applications that can make use of MPEG-4 technology have delivery requirements that are too wide to easily
characterize with a single solution. Rather, what is standardized is an interface (the Delivery Multimedia Interface
Format, or DMIF, specified in ISO/IEC 14496-6:1999) that describes the capabilities of a transport layer and the
communication between transport, multiplex, and demultiplex functions in encoders and decoders. The use of DMIF
and the MPEG-4 Systems bitstream specification allows transmission functions that are much more sophisticated
than are possible with previous MPEG standards.
However, LATM and LOAS have been defined to provide a Low overhead Audio multiplex and transport mechanism
for natural audio applications, which do not require sophisticated object-based coding or other functions provided by
MPEG-4 Systems.
The following table gives an overview about the multiplex, storage and transmission formats for MPEG-4 Audio
currently available within the MPEG-4 framework:
Format Functionality Functionality Description
defined in: redefined in:
FlexMux ISO/IEC 14496-1:2001 (MPEG- Flexible multiplex scheme
4 Systems)
(Normative)
LATM ISO/IEC 14496-3/Amd 1:2000 Low Overhead Audio Transport Multiplex
(MPEG-4 Audio V2)
(Normative)
ADIF ISO/IEC 13818-7:1997 ISO/IEC 14496-3:1999 (MPEG-2 AAC) Audio Data Interchange
Format,
(MPEG-2 Audio) (MPEG-4 Audio V1)
AAC only
(Normative) (Informative)
MP4FF ISO/IEC 14496-1/Amd. 1:2000 MPEG-4 File format
(MPEG-4 Systems V2)
(Normative)
ADTS ISO/IEC 13818-7:1997 ISO/IEC 14496-3:1999 Audio Data Transport Stream,
AAC only
(MPEG-2 Audio) (MPEG-4 Audio V1)
(Normative, Exemplarily) (Informative)
LOAS ISO/IEC I14496-3/Amd. 1:2000 Low Overhead Audio Stream, based on
LATM, three versions are available:
(MPEG-4 Audio V2)
AudioSyncStream()
(Normative, Exemplarily)
EPAudioSyncStream()
AudioPointerStream()
".
Note: This text is intended to replace the first bullet in subclause 1.1.2 (New concepts in MPEG-4 Audio) as stated in MPEG-4
Audio (ISO/IEC 14496-3:1999).
2 © ISO/IEC 2001 – All rights reserved
Transmission Storage Multiplex
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ISO/IEC 14496-3:1999/Amd.1:2000/Cor.1:2001(E)
Replace the first row of Table 3 – Complexity of Audio Object Types in subclause 5.2.2 with
"
Object Type Parameters PCU (MOPS RCU (kWords Remarks
per channel) per channel)
".
In subclause 5.2.3, replace within table footnotes *1 below Table 4 (Levels for the High Quality Audio Profile), Table 5
(Levels for the Low Delay Audio Profile), Table 6 (Levels for the Natural Audio Profile) and Table 7 (Levels for the Mobile
Audio Internetworking Profile)
"
..., which has the longest frame length, in each profile & level.
"
with
"
..., which has the longest maximum frame length, in each profile & level. For audio object types supporting variable
frame lengths and arbitrary bitrates (i.e. any AAC audio object type) this does just extend the required decoder input
buffer but does not affect the amount of redundancy actually applied.
".
In Table 8 (Syntax of AudioSpecificInfo()) in subclause 6.2.1, replace
"
epConfig; 2 bslbf
if ( epConfig == 2 )
ErrorProtectionSpecificConfig();
"
with
"
epConfig; 2 uimsbf
if ( epConfig == 2 || epConfig == 3 ) {
ErrorProtectionSpecificConfig();
}
if ( epConfig == 3 ) {
directMapping; 1 bslbf
if ( ! directMapping ) {
/* tbd */
}
}
".
In subclause 6.3.5, replace
"
This variable signals what kind of error robust configuration is used, i. e. how instances of error sensitivity
categories are obtained on decoder site.
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ISO/IEC 14496-3:1999/Amd.1:2000/Cor.1:2001(E)
Table 10: epConfig
epConfig Description
0 All instances of all sensitivity categories belonging to one frame are stored within one
access unit.
1 Each instance of each sensitivity category belonging to one frame is stored separately
within a single access unit, i.e. there are as many elementary streams existent as
instances defined within a frame.
2 The error protection decoder has to be applied. Its input is an error protected access
unit and its output are several error protection class instances. Each instance of each
sensitivity category belonging to one frame corresponds to one of these error
protection class instances.
3 Reserved
"
with
"
This data element signals what kind of error robust configuration is used.
Table 10: epConfig
epConfig Description
0 All instances of all error sensitivity categories belonging to one frame are stored within
one access unit. There exists one elementary stream per scalability layer, or just one
elementary stream in case of non-scalable configurations.
1 Each instance of each sensitivity category belonging to one frame is stored separately
within a single access unit, i.e. there exist as many elementary streams as instances
defined within a frame.
2 The error protection decoder has to be applied. Its input are error protected access
units. There exists one elementary stream per scalability layer, or just one elementary
stream in case of non-scalable configurations. The output of the EP decoder is a set of
several error protection classes. The concatenation of EP classes at the error
protection decoder output is equivalent to epConfig=0 data.
3 The error protection decoder has to be applied. Its input are error protected access
units. There exists one elementary stream per scalability layer, or just one elementary
stream in case of non-scalable configurations. The output of the EP decoder is a set of
several error protection classes. The concatenation of EP classes at the error
protection decoder output is equivalent to epConfig=0 data. The mapping between EP
classes and ESC instances is signaled by the data element directMapping.
".
After subclause 6.3.5, add
"
6.3.6 direct mapping
This data element identifies the mapping between error protection classes and error sensitivity category instances.
4 © ISO/IEC 2001 – All rights reserved
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ISO/IEC 14496-3:1999/Amd.1:2000/Cor.1:2001(E)
directMapping
directMapping Description
0 Reserved
1 Each error protection class is treated as an instance of an error sensitivity
category (one to one mapping), so that the error protection decoder output
is equivalent to epConfig=1 data.
".
To the end of subclause 6.5.1, add
"
The mechanism defined in this subclause should not be used for transmission of TTSI object (12), Main Synthetic
object (13), Wavetable Synthesis object (14), General MIDI object (15) and Algorithmic Synthesis and Audio FX
object (16). For these object types, other multiplex and transport mechanisms might be used, e.g. those defined in
MPEG-4 Systems.
".
To the description of audioMuxElementStartPointer in subclause 6.5.2.2, add
"
The maximum possible value of this field is reserved to signal that there is no start of an access unit in this sync
frame.
".
Replace Table 17 (Syntax of AudioMuxElement()) in subclause 6.5.3.1 (Syntax) with
"
Syntax No. of bitsMnemonic
AudioMuxElement( muxConfigPresent )
{
if( muxConfigPresent ) {
useSameStreamMux; 1 bslbf
if (!useSameStreamMux)
StreamMuxConfig();
}
if (audioMuxVersion == 0) {
for( i=0; i<=numSubFrames; i++ ) {
PayloadLengthInfo();
PayloadMux();
}
if( otherDataPresent ) {
for( i=0; i
otherDataBit; 1 bslbf
}
}
}
else {
/* tbd */
}
}
".
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ISO/IEC 14496-3:1999/Amd.1:2000/Cor.1:2001(E)
Replace table 18 (Syntax of StreamMuxConfig) in subclause 6.5.3.1 (Syntax) with
"
Syntax No. of bits Mnemonic
StreamMuxConfig()
{
audioMuxVersion; 1 bslbf
if (audioMuxVersion == 0) {
streamCnt = 0;
allStreamsSameTimeFraming; 1 uimsbf
numSubFrames; 6 uimsbf
numProgram; 4 uimsbf
for ( prog = 0; prog <= numProgram; prog++ ) {
numLayer; 3 uimsbf
for ( lay = 0; lay <= numLayer; lay++ ) {
progSIndx[streamCnt]=prog; laySIndx[streamCnt]=lay;
streamID [ prog][ lay] = streamCnt++;
if ( prog == 0 & lay == 0 ) {
AudioSpecificInfo();
}else {
useSameConfig; 1 uimsbf
if ( !useSameConfig )
AudioSpecificInfo();
}
frameLengthType[streamID[prog][ lay]]; 3 uimsbf
if ( frameLengthType[streamID[prog][lay] == 0 ) {
bufferFullness[streamID[prog][ lay]]; 8 uimsbf
if ( ! allStreamsSameTimeFraming ) {
if ((AudioObjectType[lay]==6 ||
AudioObjectType[lay]== 20) &&
(AudioObjectType[lay-1]==8 ||
AudioObjectType[lay-1]==24)) {
coreFrameOffset; 6 uimsbf
}
}
} else if( frameLengthType[streamID[prog][ lay]] == 1 ) {
frameLength[streamID[prog][lay]]; 9 uimsbf
} else if ( frameLengthType[streamID[prog][ lay]] == 4
frameLengthType[streamID[prog][ lay]] == 5
frameLengthType[streamID[prog][ lay]] == 3 ) {
CELPframeLengthTableIndex[streamID[prog][lay]]; 6 uimsbf
} else if ( frameLengthType[streamID[prog][ lay]] == 6
frameLengthType[streamID[prog][ lay]] == 7 ) {
HVXCframeLengthTableIndex[streamID[prog][ lay]]; 1 uimsbf
}
}
}
otherDataPresent; 1 uimsbf
if (otherDataPresent) {
otherDataLenBits = 0; /* helper variable 32bit */
do {
otherDataLenBits = otherDataLenBits * 2^8;
otherDataLenEsc; 1 uimsbf
otherDataLenTmp; 8 uimsbf
otherDataLenBits = otherDataLenBits + otherDataLenTmp;
} while (otherDataLenEsc);
6 © ISO/IEC 2001 – All rights reserved
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ISO/IEC 14496-3:1999/Amd.1:2000/Cor.1:2001(E)
}
crcCheckPresent; 1 uimsbf
if( crcCheckPresent ) crcCheckSum; 8 uimsbf
}
else {
/* tbd */
}
}
".
© ISO/IEC 2001 – All rights reserved 7
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ISO/IEC 14496-3:1999/Amd.1:2000/Cor.1:2001(E)
Replace Table 19 (Syntax of PayloadLengthInfo()) in subclause 6.5.3.1 (Syntax) with
"
Syntax No. of bits Mnemonic
PayloadLengthInfo()
{
if( allStreamsSameTimeFraming ) {
for ( prog = 0; prog <= numProgram; prog++ ) {
for ( lay = 0; lay <= numLayer; lay++ ) {
if( frameLengthType[streamID[prog][ lay]] == 0 ) {
do { /* always one complete access unit */
tmp; 8 uimsbf
MuxSlotLengthBytes[streamID[prog][ lay]] += tmp;
} while( tmp==255 );
} else {
if ( frameLengthType[streamID[prog][ lay]] == 5 ||
frameLengthType[streamID[prog][ lay]] == 7 ||
frameLengthType[streamID[prog][ lay]] == 3 ) {
MuxSlotLengthCoded[streamID[prog][ lay]]; 2 uimsbf
}
}
}
}
} else {
numChunk; 4 uimsbf
for (chunkCnt=0; chunkCnt <= numChunk; chunkCnt++) {
streamIndx; 4 uimsbf
prog = progCIndx[chunkCnt] = progSIndx[streamIndx];
lay = layCIndx[chunkCnt] = laySIndx [streamIndx];
if( frameLengthType[streamID[prog][lay]] == 0 ) {
do { /* not necessarily a complete access unit */
tmp; 8 uimsbf
MuxSlotLengthBytes[streamID[prog][lay]] += tmp;
} while (tmp == 255);
AuEndFlag[streamID[prog][lay]]; 1 bslbf
} else {
if ( frameLengthType[streamID[prog][lay]] == 5 ||
frameLengthType[streamID[prog][lay]] == 7 ||
frameLengthType[streamID[prog][lay]] == 3 ) {
MuxSlotLengthCoded[streamID[prog][lay]]; 2 uimsbf
}
}
}
}
}
".
8 © ISO/IEC 2001 – All rights reserved
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ISO/IEC 14496-3:1999/Amd.1:2000/Cor.1:2001(E)
Replace Table 20 (Syntax of PayloadMux()) in subclause 6.5.3.1 (Syntax) with
"
Syntax No. of bits Mnemonic
PayloadMux()
{
if( allStreamsSameTimeFraming ) {
for ( prog = 0; prog <= numProgram; prog++ ) {
for ( lay = 0; lay <= numLayer; lay++ ) {
payload [streamID[prog][ lay]];
}
}
} else {
for (chunkCnt=0; chunkCnt <= numChunk; chunkCnt++) {
prog = progCIndx[chunkCnt];
lay = layCIndx [chunkCnt];
payload [streamID[prog][ lay]];
}
}
}
".
In subclause 6.5.3.2 (Semantics), add
"
audioMuxVersion: A data element to signal the bitstream syntax version. possible values: 0 (default), 1 (reserved
for future extensions).
".
In subclause 6.5.3.2 (Semantics), replace
"
Note 1: There might be more than one instance of error sensitivity category 1 and 2 depending on the value of the
variable numSubFrames defined in StreamMuxConfig(). Figure 3 shows an example for the order of the
instances assuming numSubFrames is two (2).
"
with
"
Note 1: There might be more than one instance of error sensitivity category 1 and 2 depending on the value of the
variable numSubFrames defined in StreamMuxConfig(). Figure 3 shows an example for the order of the
instances assuming numSubFrames is one (1).
".
In subclause 6.5.3.2 (Semantics), replace
"
numSubFrames A field indicating how many PayloadMux() frames are multiplexed. If more than one
PayloadMux() frame are multiplexed, all PayloadMux() share a common StreamMuxConfig().The minimum value is
1.
numProgram A field indicating how many programs are multiplexed. The minimum value is 1.
numLayer A field indicating how many scalable layers are multiplexed. The minimum value is 1.
"
© ISO/IEC 2001 – All rights reserved 9
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ISO/IEC 14496-3:1999/Amd.1:2000/Cor.1:2001(E)
with
"
numSubFrames A field indicating how many PayloadMux() frames are multiplexed (numSubFrames+1). If
more than one PayloadMux() frame are multiplexed, all PayloadMux() share a common StreamMuxConfig().The
minimum value is 0 indicating 1 subframe.
numProgram A field indicating how many programs are multiplexed (numProgram+1). The minimum value is 0
indicating 1 program.
numLayer A field indicating how many scalable layers are multiplexed (numLayer+1). The minimum value is 0
indicating 1 layer.
".
In subclause 6.5.3.2 (Semantics), replace
"
numChunk A field indicating the number of payload chunks. Each chunk may belong to an access unit with a
different time base; only used if allStreamsSameTimeFraming is set to zero. The minimum value is 1.
"
with
"
numChunk A field indicating the number of payload chunks (numChunk+1). Each chunk may belong to an
access unit with a different time base; only used if allStreamsSameTimeFraming is set to zero. The minimum value
is 0 indicating 1 chunk.
".
In subclause 6.5.3.2 (Semantics), replace
"
otherDataLenBits A field indicating the length of the other data.
"
with
"
otherDataLenBits A helper variable indicating the length in bits of the other data.
otherDataLenEsc A field indicating whether there is more than one otherDataLenTmp data element following.
otherDataLenTmp A field used to calculate otherDataLenBits.
".
In subclause 6.5.3.2, replace
"
blockDelay A field indicating the time base of the payload with frameLengthType of 0. The time base is
specified by a two-layer scheme. blockDelay provides a coarse time base in multiples of tb1 =
frame_length_samples / sampling_rate. If enhanced time resolution is desired, fractionalDelay may specify an
additional fractional value.
fractionalDelayPresent A flag indicating the presence of fractionalDelay in the current payload.
fractionalDelayPresent Description
0 fractionalDelay is not present.
1 fractionalDelay is present.
10 © ISO/IEC 2001 – All rights reserved
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ISO/IEC 14496-3:1999/Amd.1:2000/Cor.1:2001(E)
fractionalDelay A field indicating the enhanced time resolution for the time base of the payload with
frameLengthType of 0.
"
with
"
bufferFullness state of the bit reservoir. It is transmitted as the number of available bits in the bit reservoir
divided by the number of audio channels divided by 32 and truncated to an integer value (mean number of 32 bit
words per channel remaining in the encoder buffer after encoding the first audio frame in the AudioMuxElement()).
A value of hexadecimal FF signals that the bitstream is a variable rate bitstream. In this case, buffer fullness is not
applicable.
coreFrameOffset identifies the first CELP frame of the current super-frame. It is defined only in case of
scalable configurations with CELP core and AAC enhancement layer(s) and transmitted with the first AAC
enhancement layer. The value 0 identifies the first CELP frame following StreamMuxConfig() as the first CELP
frame of the current super-frame. A value > 0 signals the number of CELP frames that the first CELP frame of the
current super-frame is transmitted earlier in the bitstream.
Usage of LATM in case of scalable configurations with CELP core and AAC enhancement layer(s):
Instances of the AudioMuxElement() are transmitted in equidistant manner.
The represented timeframe of one AudioMuxElement() is similar to a multiple of a super-frame timeframe.
The relative number of bits for a certain layer within any AudioMuxElement() compared to the total number of
bits within this AudioMuxElement() is equal to the relative bitrate of that layer compared to the bitrate of all
layers.
In case of coreFrameOffset=0 and bufferFullness=0, all core coder frames and all AAC frames of a certain
super-frame are stored within the same instance of AudioMuxElement().
In case of coreFrameOffset>0, several or all core coder frames are stored within previous instances of
AudioMuxElement().
Any core layer related configuration information refers to the core frames transmitted within the current instance
of the AudioMuxElement(), independent of the value of coreFrameOffset.
A specified bufferFullness is related to the first AAC frame of the first super-frame stored within the current
AudioMuxElement().
The value of bufferFullness can be used to determine the location of the first bit of the first AAC frame of the current
layer of the first super-frame stored within the current AudioMuxElement() by means of a backpointer:
backPointer = −meanFrameLength + bufferFullness + currentFrameLength
The backpointer value specifies the location as a negative offset from the current AudioMuxElement(), i. e. it
points backwards to the beginning of an AAC frame located in already received data. Any data not belonging to
the payload of the current AAC layer is not taken into account. If bufferFullness==‘0’, then the AAC frame starts
after the current AudioMuxElement().
".
In subclause 7.3.1, replace
"
Parametric Base Layer -- Configuration
For the parametric coder in unscalable mode or for the base layer in HILN scalable mode the following
ParametricSpecificConfig() is required:
ParametricSpecificConfig() {
PARAconfig();
}
© ISO/IEC 2001 – All rights reserved 11
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ISO/IEC 14496-3:1999/Amd.1:2000/Cor.1:2001(E)
Parametric HILN Enhancement / Extension Layer -- Configuration
To use HILN as core in an "T/F scalable with core" mode, in addition to the HILN base layer an HILN enhancement
layer is required. In HILN bitrate scalable operation, in addition to the HILN base layer one or more HILN extension
layers are permitted. Both the enhancement layer and the extension layer have the following
ParametricSpecificConfig():
ParametricSpecificConfig() {
HILNenexConfig();
}
"
with
"
Parametric Base Layer -- Configuration
The parametric coder in unscalable mode or the base layer in HILN scalable mode uses a
ParametricSpecificConfig() with isBaseLayer==1.
Parametric HILN Enhancement / Extension Layer -- Configuration
To use HILN as core in a "T/F scalable with core" mode, in addition to the HILN base layer an HILN enhancement
layer is required. In HILN bitrate scalable operation, in addition to the HILN base layer one or more HILN extension
layers are permitted. Both the enhancement and extension layer use a ParametricSpecificConfig() with
isBaseLayer==0.
ParametricSpecificConfig() {
isBaseLayer; 1 bit uimsbf
if ( isBaseLayer ) {
PARAconfig();
}
else {
HILNenexConfig();
}
}
",
and at the end of subclause 7.3.1, add
"
isBaseLayer A one-bit identifier representing whether the corresponding layer is the base layer (1) or an
enhancement or extension layer (0).
".
In subclause 7.3.2.3, replace
"
Table 72: LARH3 code ( harmLAR[7.25] )
"
with
"
Table 72: LARH3 code ( harmLAR[7.24] )
",
12 © ISO/IEC 2001 – All rights reserved
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ISO/IEC 14496-3:1999/Amd.1:2000/Cor.1:2001(E)
and replace
"
Table 74: LARN2 code ( noiseLAR[2.25] )
"
with
"
Table 74: LARN2 code ( noiseLAR[2.24] )
".
In Table 25 and in 7.4.1.1, replace " extensionFlag " with " PARAextensionFlag ".
In subclause in 7.5.1.4.3, add
"
If the speed is controlled by the time scaling factor in the speed field of the AudioSource BIFS node, the speed
change factor is:
speedFactor = 1 / speed;
If the pitch is controlled by the pitch field of the AudioSource BIFS node, the pitch change factor is:
pitchFactor = pitch;
"
after
"
If playback at the original speed and pitch is desired, the corresponding control factors are set to their default
values:
speedFactor = 1.0;
pitchFactor = 1.0;
".
© ISO/IEC 2001 – All rights reserved 13
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ISO/IEC 14496-3:1999/Amd.1:2000/Cor.1:2001(E)
Replace Table 80 in subclause 8.2.1 with
"
Table 80: Syntax of GASpecificConfig()
Syntax No. of bits Mnemonic
GASpecificConfig ( samplingFrequencyIndex,
channelConfiguration,
audioObjectType )
{
frameLengthFlag; 1 bslbf
dependsOnCoreCoder; 1 bslbf
if ( dependsOnCoreCoder ) {
coreCoderDelay; 14 uimsbf
}
extensionFlag; 1 bslbf
if ( ! channelConfiguration ) {
program_config_element ();
}
if ((audioObjectType == 6) || (audioObjectType == 20)) {
layerNr; 3 uimsbf
}
if ( extensionFlag ) {
if ( audioObjectType == 22 ) {
numOfSubFrame; 5 bslbf
layer_length; 11 bslbf
}
if ( audioObjectType == 17 || audioObjectType == 18 ||
audioObjectType == 19 || audioObjectType == 20 ||
audioObjectType == 21 || audioObjectType == 23 ) {
aacSectionDataResilienceFlag; 1 bslbf
aacScalefactorDataResilienceFlag; 1 bslbf
aacSpectralDataResilienceFlag; 1 bslbf
}
extensionFlag3; 1 bslbf
if ( extensionFlag3 ) {
/* tbd in version 3 */
}
}
}
".
Important notice: This correction also affects ISO/IEC 14496-3:1999.
To subclause 8.2.2 (Semantics), add
"
layerNr: A 3-bit field indicating the AAC layer number in a scalable configuration. The first AAC layer is signaled by
a value of 0.
".
To subclause 8.2.2 (Semantics), add
"
ExtensionFlag3: Shall be ‘0’.
".
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ISO/IEC 14496-3:1999/Amd.1:2000/Cor.1:2001(E)
In subclause 8.5.3.1.2, replace
"
If the aacSectionDataResilienceFlag is set, sect_len is not transmitted but is set to one per default in case the
codebook for a section is 11 or in the range of 16 and 31.
"
with
"
If the aacSectionDataResilienceFlag is set, sect_len_incr is not transmitted but is set to one per default in case the
codebook for a section is 11 or in the range of 16 and 31.
".
In subclause 8.5.3.2.2, replace
"
sf_concealment is a data field that signals whether the scalefactors of the last frame are similar to the current ones
or not. The length of this data field is 1 bit.
"
with
"
sf_concealment: is a data field that indicates the similarity between scale factors of the last frame and those of the
current one. It shall be set to ‘0’, if the scale factors of the last frame are dissimilar to those of the current frame. It
shall set to ‘1’, if they are similar.
Note: This data field is not required to decode error-free payload, but might be used to apply appropriate
concealment strategies in case of corrupted scale factor data. No similarity criterion is specified since concealment
is out of the scope of this standard.
".
In subclause 8.5.3.3.3.1, replace
"
For explanation of the pre-sorting steps the term “unit” is introduced. A unit covers four spectral lines, i. e. two two-
dimensional codewords or one four-dimensional codeword.
"
with
"
For explanation of the pre-sorting steps the term “unit” is introduced. A unit covers four spectral lines, i. e. two two-
dimensional codewords or one four-dimensional codeword. In case of two two-dimensional codewords their natural
order is kept, i. e. the higher frequency codeword follows the lower frequency codeword.
".
In subclause 8.5.3.3.3.1, replace the definition
"
codebookPriority[32] = {x,0,0,1,1,2,2,3,3,4,4,21,x,x,x,x,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20}
"
with
© ISO/IEC 2001 – All rights reserved 15
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ISO/IEC 14496-3:1999/Amd.1:2000/Cor.1:2001(E)
"
codebookPriority[32] = {x,21,21,20,20,19,19,18,18,17,17,0,x,x,x,x,16,15,14,13,12,11,10,9,8,7,6,5,4,3,2,1}
".
In subclause 9.1, delete
"
The stream type ERROR_PROTECTION_STREAM is defined. This stream consists of error protection frames.
".
And in subclause 9.2.2, replace
"
This part defines the syntax of the stream type ERROR_PROTECTION_STREAM which consists of error protection
frames. Note that this stream is common for all algorithms. In case this stream is transported by 14496-1 Systems,
one rs_ep_frame() is mapped to one access unit.
"
with
"
This part defines the syntax of the error protected audio bitstream payload. This kind of syntax can be selected by
setting epConfig = 2. It is common for all audio object types. If MPEG-4 Systems is used, one rs_ep_frame() is
directly mapped to one access unit.
".
In the Table 163: Syntax of ErrorProtectionSpecificConfig() in subclause 9.2.1, replace
"
class_rate[i][j] 5 uimsbf
"
with
"
if(fec_type[i][j]){
class_rate[i][j] 7 uimsbf
}else{
class_rate[i][j] 5 uimsbf
}
".
In description of class_crclen[i][j] in subclause 9.3.1, replace
" (See subclause 9.4.8.2.2) " with " (See subclause 9.4.5) ".
16 © ISO/IEC 2001 – All rights reserved
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ISO/IEC 14496-3:1999/Amd.1:2000/Cor.1:2001(E)
In subclause 10.3.1.1, replace
"
Table 196: Syntax of ErHVXCfixframe ()
Syntax No. of bits Mnemonic
ErHVXCfixframe(rate)
{
if(rate == 2000){
2k_ESC0();
if(VUV!=0){
2kV_ESC1();
2kV_ESC2();
2kV_ESC3();
2kV_ESC4();
}
else{
2kUV_ESC1();
2kUV_ESC2();
2kUV_ESC3();
}
}
else if (rate >= 3700){
4k_ESC0();
if(VUV!=0){
4kV_ESC1(rate);
4kV_ESC2(rate);
4kV_ESC3();
4kV_ESC4();
}
else{
4kUV_ESC1(rate);
4kUV_ESC2(rate);
}
}
}
"
with
© ISO/IEC 2001 – All rights reserved 17
---------------------- Page: 17 ----------------------
ISO/IEC 14496-3:1999/Amd.1:2000/Cor.1:2001(E)
"
Table 196: Syntax of ErHVXCfixframe()
Syntax No. of bits Mnemonic
ErHVXCfixframe(rate)
{
if (rate == 2000) {
2k_ESC0();
2k_ESC1()
2k_ESC2();
2k_ESC3();
}
else if (rate >= 3700) {
4k_ESC0(rate);
4k_ESC1(rate)
4k_ESC2();
4k_ESC3();
4k_ESC4(rate);
}
}
".
In subclauses 10.3.1.1.1-
...
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