Title of Invention

DEVICE AND METHOD FOR RECONSTRUCTION OF MULTI-CHANNEL AUDIO SIGNAL FOR GENERATING A PARAMETER DATACERT

Abstract The invention relates to a device for generating a multi-channel signal using input data which comprises transmission channel data representing M transmission channels and parameter data to obtain K output channels, wherein the M transmission channels and the parameter data together represent N original channels, wherein M is less than N and equal to or larger than 1, and wherein K is larger than M, wherein the input data comprise a parameter configuration cue (41), comprising multi-channel reconstruction means (24) designed to generate the K output channels from the transmission channel data and the parameter data; and configuration means (26) for configuring the multi-channel reconstruction means, wherein the configuration means is designed to read the input data to interpret (30) the parameter configuration cue, when the parameter configuration cue has a first meaning, extract (31) configuration information contained in the input data and effect (34) a configuration setting of the multi-channel reconstruction means, and when the parameter configuration cue has a second meaning differing from the first meaning, configure (34) the multi-channel reconstruction means using information on a coding algorithm (23) with which the transmission channel data have been decoded from a coded version thereof so that the configuration setting of the multi - channel reconstruction means is identical to a configuration setting of the coding algorithm (23) or depends on a configuration setting of the coding algorithm (23).
Full Text Description
The present invention relates to parametric multi-channel
processing techniques and, in particular, to
encoders/decoders for generating and/or reading a flexible
data syntax and for associating parameter data with the
data of the downmix and/or transmission channels.
In addition to the two stereo channels, a recommended
multi-channel surround representation includes a center
channel C and two surround channels, i.e. the left surround
channel Ls and the right surround channel Rs, and
additionally, if applicable, a subwoofer channel also
referred to as LFE channel (LFE = Low Frequency
Enhancement). This reference sound format is also referred
to as 3/2 (plus LFE) stereo and recently also as 5.1 multi-
channel, which means that there are three front channels
and two surround channels. In general, five or six
transmission channels are required. In a reproduction
environment, at least five loudspeakers are required in the
respective five different positions to obtain an optimal
so-called sweet spot a determined distance from the five
correctly placed loudspeakers. However, with respect to its
positioning, the subwoofer is usable in a relatively free
way.
There are several techniques for reducing the amount of
data required to transmit a multi-channel audio signal.
Such techniques are also called joint stereo techniques.
For this purpose, reference is made to Fig. 5. Fig. 5 shows
a joint stereo device 60. This device may be a device
implementing, for example, the intensity stereo technique
(IS technique) or the binaural cue coding technique (BCC
technique). Such a device generally receives at least two

channels (CH1, CH2, ... CHn) as input signal and outputs at
least one single carrier channel (downmix) and parametric
data, i.e. one or more parameter sets. The parametric data
are defined so that an approximation of each original
channel (CH1, CH2, ... CHn) may be calculated in a decoder.
Normally, the carrier channel will include subband samples,
spectral coefficients or time domain samples, etc., which
provide a comparatively fine representation of the
underlying signal, while the parametric data and/or
parameter sets do not include any such samples or spectral
coefficients. Instead, the parametric data include control
parameters for controlling a determined reconstruction
algorithm, such as weighting by multiplication, time
shifting, frequency shifting, .... The parametric data thus
include only a comparatively rough representation of the
signal or the associated channel. Expressed in numbers, the
amount of data required by a carrier channel (which is
compressed, i.e. coded by means of AAC, for example) is in
the range of 60 to 70 kbit/s, while the amount of data
required by parametric side information is in the order
from 1.5 kbit/s for a channel. One example for parametric
data are the known scaling factors, intensity stereo
information or binaural cue parameters, as will be
described below.
The intensity stereo coding technique is described in the
AES preprint 3799 entitled "Intensity stereo coding" J.
Herre, K. H. Brandenburg, D. Lederer, February 1994,
Amsterdam. In general, the concept of intensity stereo is
based on a main axis transform which is to be applied to
data of the two stereophonic audio channels. If most data
points are placed around the first main axis, a coding gain
may be achieved by rotating both signals by a determined
angle prior to the coding. However, this does not always
apply to real stereophonic reproduction techniques. The
reconstructed signals for the left and right channels
consist of differently weighted or scaled versions of the

same transmitted signal. Nevertheless, the reconstructed
signals differ in amplitude, but they are identical with
respect to their phase information. The energy time
envelopes of both original audio channels, however, are
maintained by means of the selective scaling operation
typically operating in frequency-selective fashion. This
corresponds to the human sound perception at high
frequencies where the dominant spatial cues are determined
by the energy envelopes.
In addition, in practical implementations the transmitted
signal, i.e. the carrier channel, is formed of the sum
signal of the left channel and the right channel instead of
rotating both components. Furthermore, this processing,
i.e. the generation of the intensity stereo parameters for
performing the scaling operation, is performed in a
frequency-selective way, i.e. independently of each other
for each scale factor band, i.e. for each encoder frequency
partition. Preferably, both channels are combined to form a
combined or "carrier" channel. In addition to the combined
channel, the intensity stereo information is determined
which depends on the energy of the first channel, the
energy of the second channel and the energy of the combined
or sum channel.
The BCC technique is described in the AES convention paper
5574 entitled "Binaural cue coding applied to stereo and
multi-channel audio compression", C. Faller, F. Baumgarte,
May 2002, Miinchen. In BCC coding, a number of audio input
channels is converted to a spectral representation using a
DFT-based transform with overlapping windows. The resulting
spectrum is divided into non-overlapping partitions. Each
partition has a bandwidth proportional to an equivalent
right-angled bandwidth (ERB). So-called inter-channel level
differences (ICLD) as well as so-called inter-channel time
differences (ICTD) are calculated for each partition, i.e.
for each band and for each frame k, i.e. a block of time
samples. The ICLD and ICDT parameters are quantized and

coded to obtain a BCC bit stream. The inter-channel level
differences and the inter-channel time differences are
given for each channel with respect to a reference channel.
In particular, the parameters are calculated according to
predetermined formulae depending on the particular
divisions of the signal to be processed.
On the decoder side, the decoder receives a mono signal and
the BCC bit stream, i.e. a first parameter set for the
inter-channel time differences and a second parameter set
for the inter-channel level differences per frame. The mono
signal is transformed to the frequency domain and input
into a synthesis block also receiving decoded ICLD and ICTD
values. In the synthesis block or reconstruction block, the
BCC parameters (ICLD and ICTD) are used to perform a
weighting operation of the mono signal to reconstruct the
multi-channel signal, which then, after a frequency/time
conversion, represents a reconstruction of the original
multi-channel audio signal.
In the case of BCC, the joint stereo module 60 operates to
output the channel side information so that the parametric
channel data are quantized and coded ICLD and ICTD
parameters, wherein one of the original channels may be
used as reference channel for coding the channel side
information. Normally, the carrier channel is formed of the
sum of the participating original channels.
Of course, the above technique only provides a mono
representation for a decoder which is only able to decode
the carrier channel, but which is not capable of generating
the parameter data for generating one or more
approximations of more than one input channel.
The audio coding technique referred to as BCC technique is
further described in the US patent applications US
2003/0219130 Al, 2003/0026441 Al and 2003/0035553 Al. In
addition, further see "Binaural Cue Coding. Part. II:

Schemes and Applications", C. Faller and F. Baumgarte,
IEEE: Transactions on Audio and Speech Proc, Vol. 11, No.
6, November 1993. Further, also see C. Faller and F.
Baumgarte "Binaural Cue Coding applied to Stereo and Multi-
Channel Audio compression", Preprint, 112th Convention of
the Audio Engineering Society (AES), May 2002, and J.
Herre, C. Faller, C. Ertel, J. Hilpert, A. Hoelzer, C.
Spenger „MP3 Surround: Efficient and Compatible Coding of
Multi-Channel Audio", 116th AES Convention, Berlin, 2004,
Preprint 6049. In the following, there will be represented
a typical general BCC scheme for multi-channel audio coding
in more detail with respect to Figs. 6 to 8. Fig. 6 shows a
general BCC coding scheme for coding/transmission of multi-
channel audio signals. The multi-channel audio input signal
is input at an input 110 of a BCC encoder 112 and is "mixed
down" in a so-called downmix block 114, i.e. converted to a
single sum channel. In the present example, the signal at
the input 110 is a 5-channel surround signal having a front
left channel and a front right channel, a left surround
channel and a right surround channel, and a center channel.
Typically, the downmix block generates a sum signal by
simple addition of these five channels into a mono signal.
Other downmix schemes are known in the art, all resulting
in generating, using a multi-channel input signal, a
downmix signal having a single channel or having a number
of downmix channels which, in any case, is less than the
number of original input channels. In the present example,
a downmix operation would already be achieved if four
carrier channels were generated from the five input
channels. The single output channel and/or the number of
output channels is output on a sum signal line 115.
Side information obtained by a BCC analysis block 116 are
output on a side information line 117. In the BCC analysis
block, inter-channel level differences (ICLD), inter-
channel time differences (ICTD) or inter-channel
correlation values (ICC values) may be calculated. Thus,
there are three different parameter sets, namely the inter-

channel level differences (ICLD), the inter-channel time
differences (ICTD) and the inter-channel correlation values
(ICC) , for the reconstruction in the BCC synthesis block
122.
The sum signal and the side information with the parameter
sets are typically transmitted to a BCC decoder 120 in a
quantized and coded format. The BCC decoder splits the
transmitted (and decoded, in the case of a coded
transmission) sum signal into a number of subbands and
performs scalings, delays and further processing to
generate the subbands of the several channels to be
reconstructed. This processing is performed so that the
ICLD, ICTD and ICC parameters (cues) of a reconstructed
multi-channel signal at output 121 are similar to the
respective cues for the original multi-channel signal at
input 110 into the BCC encoder 112. For this purpose, the
BCC decoder 120 includes a BCC synthesis block 122 and a
side information processing block 123.
The following will illustrate the internal structure of the
BCC synthesis block 122 with respect to Fig. 7. The sum
signal on the line 115 is input into a time/frequency
conversion block typically embodied as filter bank FB 125.
At the output of block 125, there is a number N of subband
signals or, in an extreme case, a block of spectral
coefficients, if the audio filter bank 125 performs a
transform generating N spectral coefficients from N time
domain samples.
The BCC synthesis block 122 further includes a delay stage
126, a level modification stage 127, a correlation
processing stage 128 and a stage IFB 129 representing an
inverse filter bank. At the output of the stage 12 9, the
reconstructed multi-channel audio signal having, for
example, five channels in the case of a 5-channel surround
system may be output on a set of loudspeakers 124, as
illustrated in Fig. 6.

Fig. 7 further illustrates that the input signal s (n) is
converted to the frequency domain or filter bank domain by
means of element 125. The signal output by element 125 is
multiplied so that several versions of the same signal are
obtained, as indicated by node 130. The number of versions
of the original signal is equal to the number of output
channels in the output signal to be reconstructed. If each
version of the original signal is subjected to a determined
delay di, d2, ... di, dN at the node 130, the result is the
situation at the output of blocks 126, which includes the
versions of the same signal, but with different delays. The
delay parameters are calculated by the side information
processing block 123 in Fig. 6 and derived from the inter-
channel time differences as they were determined by the BCC
analysis block 116.
The same applies to the multiplication parameters ai, a2 ...
ai, aN, which are also calculated by the side information
processing block 123 based on the inter-channel level
differences determined by the BCC analysis block 116.
The ICC parameters are calculated by the BCC analysis block
116 and used for controlling the functionality of the block
128 so that determined correlation values between the
delayed and level-manipulated signals are obtained at the
output of block 128. It is to be noted that the order of
the stages 126, 127, 128 may be different from that
represented in Fig. 7.
It is further to be noted that, in a blockwise processing
of the audio signal, the BCC analysis is also performed
blockwise. Furthermore, the BCC analysis is also performed
frequency-wise, i.e. in a frequency-selective way. This
means that, for each spectral band, there is an ICLD
parameter, an ICTD parameter and an ICC parameter for each
block. The ICTD parameters for at least one block for at
least one channel across all bands' thus represent the ICTD

parameter set. The same applies to the ICLD parameter set
representing all ICLD parameters for at least one block for
all frequency bands for the reconstruction of at least one
output channel. The same applies, in turn, to the ICC
parameter set which again includes several individual ICC
parameters for at least one block for various bands for the
reconstruction of at least one output channel on the basis
of the input channel or sum channel.
In the following, reference is made to Fig. 8 showing a
situation from which the determination of BCC parameters
may be seen. Normally, the ICLD, ICTD and ICC parameters
may be defined between any channel pairs. Typically a
determination of the ICLD and the ICTD parameters is
performed between a reference channel and each other input
channel, so that there is a distinct parameter set for each
of the input channels except the reference channel. This is
also illustrated in Fig. 8A.
However, the ICC parameters may be defined differently. In
general, ICC parameters may be generated in the encoder
between any channel pairs, as also illustrated
schematically in Fig. 8B. In this case, a decoder would
perform an ICC synthesis so that approximately the same
result is obtained as it was present in the original signal
between any channel pairs. However, there has been the
suggestion to calculate only ICC parameters between the two
strongest channels at any time, i.e. for each time frame.
This scheme is represented in Fig. 8C, which shows an
example in which, at one time, an ICC parameter between the
channels 1 and 2 is calculated and transmitted, and in
which, at another time, an ICC parameter between the
channels 1 and 5 is calculated. The decoder then
synthesizes the inter-channel correlation between the two
strongest channels in the decoder and executes further
typically heuristic rules for synthesizing the inter-
channel coherence for the remaining channel pairs.

With respect to the calculation of, for example, the
multiplication parameters ai, ... aN based on the transmitted
ICLD parameters, reference is made to the cited AES
convention paper 5574. The ICLD parameters represent an
energy distribution in an original multi-channel signal.
Without loss of generality, Fig. 8A shows that there are
four ICLD parameters representing the energy difference
between all other channels and the front left channel. In
the side information processing block 123, the
multiplication parameters ai, ... aN are derived from the
ICLD parameters so that the total energy of all
reconstructed output channels is the same energy as present
for the transmitted sum signal or is at least proportional
to this energy. One way to determine these parameters is a
two-stage process in which, in a first stage, the
multiplication factor for the left front channel is set to
1, while multiplication factors for the other channels in
Fig. 8C are set to the transmitted ICLD values. Then, in a
second stage, the energy of all five channels is calculated
and compared to the energy of the transmitted sum signal.
Then, all channels are downscaled, namely using a scaling
factor which is equal for all channels, wherein the scaling
factor is selected so that the total energy of all
reconstructed output channels after the scaling is equal to
the total energy of the transmitted sum signal and/or the
transmitted sum signals.
With respect to the inter-channel coherence measure ICC
transmitted from the BCC encoder to the BCC decoder as
further parameter set, it is to be noted that a coherence
manipulation could be performed by modification of the
multiplication factors, such as by multiplying the
weighting factors of all subbands by random numbers having
values between 201ogl0"6 and 201ogl06. The pseudo random
sequence is typically selected so that the variance for all
critical bands is approximately equal and that the average
value within each critical band is zero. The same sequence
is used for the spectral coefficients of each different

frame or block. Thus, the width of the audio scene is
controlled by modifications of the variances of the pseudo
random sequence. A larger variance generates a larger
hearing width. The variance modification may be performed
in individual bands having a width of a critical band. This
allows the simultaneous existence of several objects in a
hearing scene, wherein each object has a different hearing
width. A suitable amplitude distribution for the pseudo
random sequence is a uniform distribution on a logarithmic
scale, such as represented in the US patent publication
2002/0219130 Al.
In order to transmit the five channels in a compatible way,
for example in a bit stream format which is also suitable
for a normal stereo decoder, there may be used the so-
called matrixing technique described in "MUSICAM Surround:
A universal multi-channel coding system compatible with
ISO/IEC 11172-3", G. Theile and G. Stoll, AES Preprint,
October 1992, San Francisco.
Furthermore, see further multi-channel coding techniques
described in the publication "Improved MPEG 2 Audio multi-
channel encoding", B. Grill, J. Herre, K. H. Brandenburg,
E. Eberlein, J. Roller, J. Miller, AES Preprint 3865,
February 1994, Amsterdam, wherein a compatibility matrix is
used to obtain the downmix channels from the original input
channels.
In summary, you can say that the BCC technique allows an
efficient and also backward-compatible coding of multi-
channel audio material, as also described, for example, in
the specialist publication by E. Schuijer, J. Breebaart, H.
Purnhagen, J. Engdegard entitled "Low-Complexity Parametric
Stereo Coding", 119th AES Convention, Berlin, 2004,
Preprint 6073. In this context, mention should also be made
of the MPEG-4 standard and particularly the expansion to
parametric audio techniques, wherein this standard part is
also known by the designation ISO/IEC 14496-3: 2001/FDAM 2

(Parametric Audio). In this respect, there should be
mentioned, in particular, the syntax in table 8.9 of the
MPEG-4 standard entitled "syntax of the ps.data()". In this
example, we should mention the syntax elements "enable_icc"
and "enable_ipdopd", wherein these syntax elements are used
to turn on and off a transmission of an ICC parameter and a
phase corresponding to inter-channel time differences.
There should further be mentioned the syntax elements
"icc_data()" "ipd_data()" and "opd_data()".
In summary, it is to be noted that generally such
parametric multi-channel techniques are used employing one
or several transmitted carrier channels, wherein M
transmitted channels are formed from N original channels to
reconstruct again the N output channels or a number K of
output channels, wherein K is equal to or less than the
number of original channels N.
As can be seen from Fig. 6, the BCC analysis is a typical
separate preprocessing to generate parameter data on the
one hand and one or more transmission channels (downmix
channels) on the other hand from a multi-channel signal
having N original channels. Typically, these downmix
channels are then compressed for example by means of a
typical MP3 or AAC stereo/mono encoder, although this is
not shown in Fig. 6, so that, on the output side, there is
a bit stream representing the transmission channel data in
compressed form and that there is further another bit
stream representing the parameter data. The BCC analysis
thus occurs separately from the actual audio coding of the
downmix channels and/or the sum signal 115 of Fig. 6.
The decoder side is similar. A decoder having multi-channel
ability will first decode the bit stream including the
compressed downmix signal depending on the used coding
algorithm and again provide one or more transmission
channels on the output side, i.e. typically as a time
sequence of PCM data (PCM = Pulse Code Modulation) . Then,

the BCC synthesis will take place as a distinct separate
and isolated postprocessing which signals self-sufficiently
with the parameter data stream and is provided with data to
generate, on the output side, several output channels
preferably equal to the number of the original input
channels from the audio-decoded downmix signal.
Thus, it is an advantage of the BCC analysis that it has a
distinct filter bank for the purposes of the BCC analysis
and a distinct filter bank for the purposes of the BCC
synthesis, for example, so that it is separate from the
filter bank of the audio encoder/decoder in order not to
have to make any compromises regarding audio compression on
the one hand and multi-channel reconstruction on the other
hand. Generally speaking, the audio compression is thus
done separately from the multi-channel parameter processing
to be optimally equipped for both fields of application.
However, this concept has the disadvantage that a complete
signaling has to be transmitted both for the multi-channel
reconstruction and for the audio decoding. This is
particularly disadvantageous when, as will typically be the
case, both the audio decoder and the multi-channel
reconstruction means perform the same or similar steps and
thus require the same and/or mutually dependent
configuration settings. Due to the completely separate
concept, signaling data are thus transmitted twice
resulting in an artificial "expansion" of the data amount,
which is ultimately due to the fact that one has chosen the
separate concept between audio coding/decoding and multi-
channel analysis/synthesis.
On the other hand, a complete "linking" of the multi-
channel reconstruction to the audio decoding would
considerably restrict the flexibility, because in that case
the actually important goal of the separation of both
processing steps to be able to perform each processing step
in an optimal way would have to be given up. Thus,

considerable quality losses would arise, in particular in
the case of several successive coding/decoding stages also
referred to as "tandem" coding. If there is a complete
linking of the BCC data to the coded audio data, a multi-
channel reconstruction has to be performed with each
decoding to perform a multi-channel synthesis again when
recoding. Since it is the nature of every parametric
technique that it is lossy, losses will accumulate by
repeated analysis synthesis analysis so that, with each
encoder/decoder stage, the perceptible quality of the audio
signal further decreases.
In this case, decoding/encoding of audio data without
simultaneous analysis/synthesis processing of the parameter
data would only be possible if each audio codec in the
tandem chain worked identically, i.e. had the same sampling
rate, block length, advance length, windowing, transform,
..., i.e. had generally the same configuration, and if, in
addition, the respective block boundaries also were
maintained. Such a concept, however, would considerably
restrict the flexibility of the whole concept. Particularly
regarding the fact that the parametric multi-channel
techniques are intended to supplement already existing
stereo data, for example, by additional parameter data,
this limitation is all the more painful. Since the already
existing stereo data may originate from many different
encoders that all use different block lengths or that do
not even operate in the frequency domain, but in the time
domain etc., such a limitation would take the concept of
the later supplementation ad absurdum from the beginning.
It is the object of the present invention to provide a
flexible and efficient concept for generating a multi-
channel audio signal or a reconstruction parameter data
set.
This object is achieved by a device for generating a multi-
channel signal according to claim 1, a method for

generating a multi-channel signal according to claim 14, a
device for generating a parameter data set according to
claim 15, a method for generating a parameter data output
according to claim 18, a device for generating a parameter
data output according to claim 19, a method for generating
a parameter data output according to claim 20, or a
computer program according to claim 21.
The present invention is based on the finding that
efficiency on the one hand and flexibility on the other
hand may be achieved by having the data stream, which can
include transmission channel data and parameter data,
contain a parameter configuration cue that has been
inserted on the encoder side and is evaluated on the
decoder side. This cue indicates whether a multi-channel
reconstruction means is configured from the input data,
i.e. from the data transmitted from the encoder to the
decoder, or whether a multi-channel reconstruction means is
configured by a cue to a coding algorithm with which coded
transmission channel data have been decoded. The multi-
channel reconstruction means has a configuration setting
identical to a configuration setting of the audio decoder
for decoding the coded transmission channel data or at
least dependent on this setting.
If a decoder detects the first situation, i.e. the
parameter configuration cue has a first meaning, the
decoder will look for further configuration information in
the received input data, to properly configure the multi-
channel reconstruction means, to use the information then
to effect a configuration setting of the multi-channel
reconstruction means. Such a configuration setting could
be, for example, block length, advance, sampling frequency,
filter bank control data, so-called granule information
(how many BCC blocks there are in a frame), channel
configurations (e.g. a 5.1. output is generated whenever
there is "mp3"), information on which parameter data are

obligatory in a scaled case (e.g. ICLD) and which are not
(ICTD), etc.
If, however, the decoder determines that the parameter
configuration cue has a second meaning different from the
first meaning, the multi-channel reconstruction means will
choose the configuration setting in the multi-channel
reconstruction means depending on information about the
audio coding algorithm on which the coding/decoding of the
transmission channel data, i.e. the downmix channels, is
based.
In contrast to the separate concept of the parameter data
on the one hand and the compressed downmix data on the
other hand, the inventive device for generating a multi-
channel audio signal commits a "theft", so to speak, for
the configuration of the multi-channel reconstruction
means, in the actually completely separate and self-
sufficient audio data and/or in an upstream audio decoder
operating self-sufficiently, to configure itself.
The inventive concept is particularly powerful in a
preferred embodiment of the present • invention when
different audio coding algorithms are considered. In this
case, a large amount of explicit signaling information
would have to be transmitted for achieving a synchronous
operation, i.e. an operation in which the multi-channel
reconstruction means operates synchronously with the audio
decoder, namely the corresponding advance lengths, etc. for
each different coding algorithm, so that the actually
independent multi-channel reconstruction algorithm runs
synchronously with the audio decoding algorithm.
According to the invention, the parameter configuration
cue, for which a single bit is sufficient, signals to a
decoder that, for the purpose of its configuration, it is
to look which audio encoder it is downstream to. Following
this, the decoder will receive information on which audio

encoder is currently upstream to a number of different
audio encoders. When it has received this information, it
will preferably enter a configuration table deposited in
the multi-channel decoder with this audio coding algorithm
identification to there retrieve the configuration
information predefined for each of the possible audio
coding algorithms to effect at least one configuration
setting of the multi-channel reconstruction means. This
achieves a significant data rate saving as compared to the
case in which the configuration is explicitly signaled in
the data stream, in which there is thus no consideration
between the multi-channel reconstruction means and the
audio decoder, and in which there is no inventive "theft"
of audio decoder data by the multi-channel reconstruction
means either.
On the other hand, the inventive concept still provides the
high flexibility inherent to the explicit signaling of
configuration information, because, due to the parameter
configuration cue, for which a single bit in the data
stream is sufficient, there is the possibility to actually
transmit all configuration information in the data stream,
if needed, or - as a mixed form - to transmit at least part
of the parameter configuration information in the data
stream and to take another part of necessary information
from a set of laid down information.
In a preferred embodiment of the present invention, the
data transmitted from the encoder to the decoder further
include a continuation cue signaling to a decoder whether
it should change configuration settings at all in
comparison to already existing or previously signaled
configuration settings, or whether it should continue as
before, or whether, as a reaction to a certain setting of
the continuation cue, the parameter configuration cue is
read in to determine whether there should be an alignment
of the multi-channel reconstruction means with respect to
the audio decoder, or whether at least partially explicit

information regarding the configuration are contained in
the transmission data.
Preferred embodiments of the present invention will be
explained in more detail in the following with respect to
the accompanying drawings, in which:
Fig. 1 is a block circuit diagram of an inventive device
for generating a parameter data set usable on the
encoder side;
Fig. 2 is a block circuit diagram of a device for
generating a multi-channel audio signal used on
the decoder side;
Fig. 3 is a principle flow chart of the operation of the
configuration means of Fig. 2 in a preferred
embodiment of the present invention;
Fig. 4a is a schematic representation of the data streams
for a synchronous operation between audio decoder
and multi-channel reconstruction means;
Figs. 4b is a schematic representation of the data streams
for an asynchronous operation between audio
decoder and multi-channel reconstruction means;
Figs. 4c is a preferred embodiment of the device for
generating a multi-channel audio signal in syntax
form;
Fig. 5 is a general representation of a multi-channel
encoder;
Fig. 6 is a schematic block diagram of a BCC encoder/BCC
decoder path;

Fig. 7 is a block circuit diagram of the BCC synthesis
block of Fig. 6; and
Figs. 8A to 8C are a representation of typical scenarios
for the calculation of the parameter sets ICLD,
ICTD and ICC.
Fig. 1 shows a block circuit diagram of an inventive device
for generating a parameter data set, wherein the parameter
data set may be output at an output 10 of the device shown
in Fig. 1. The parameter data set contains parameter data
which, together with transmission channel data not
illustrated in Fig. 1, but which will be discussed later,
represent N original channels, wherein the transmission
channel data will typically include M transmission
channels, wherein the number M of transmission channels is
smaller than the number N of original channels and is equal
to or larger than 1.
The device shown in Fig. 1, which will be accommodated on
the encoder side, includes multi-channel parameter means 11
designed to perform, for example, a BCC analysis or an
intensity stereo analysis or the like. In this case, the
multi-channel parameter means 11 will receive N original
channels at an input 12. Alternatively, however, the multi-
channel parameter means 11 may also be designed as
transcoder means to generate the parameter data at the
output of means 11 using existing raw parameter data fed
into a raw parameter input 13. If the parameter data are
simple BCC data as they are provided by any BCC analysis
means, the processing of the multi-channel parameter means
11 will simply consist in a copying function of the data
from the input 13 into an output of means 11. However, the
multi-channel parameter means 11 may also be designed to
change the syntax of the raw parameter data stream to add,
for example, signaling data or to write parameter sets that
may be decoded or skipped at least partially independent of
each other from the existing raw parameter data.

The device shown in Fig. 1 further includes signaling means
14 for determining and associating a parameter
configuration cue PKH with the parameter data at the output
of means 11. In particular, the signaling means is designed
to determine the parameter configuration cue such that it
has a first meaning when configuration information
contained in the parameter data set are to be used for a
multi-channel reconstruction. Alternatively, the signaling
means 14 will determine the parameter configuration cue
such that it has a second meaning when configuration data
that are based on a coding algorithm that is to be used
and/or has been used for coding the transmission channel
data are to be used for a multi-channel reconstruction.
Finally, the inventive device of Fig. 1 includes
configuration data writing means 15 designed to associate
configuration information with the parameter data and the
parameter configuration cue to finally obtain the parameter
data set at output 10. The parameter data set 10 thus
includes the parameter data from the multi-channel
parameter means 11, the parameter configuration cue PKH
from the signaling means 14 and, if applicable,
configuration data from the configuration data writing
means 15. In the parameter data set, these elements of the
data set are arranged according to a determined syntax and
are typically time multiplexed, as symbolically represented
by an element generally referred to as combination means 16
in Fig. 1.
In a preferred embodiment of the present invention, the
signaling means 14 is coupled to the configuration data
writing means 15 via a control line 17 to activate the
configuration data writing means 15 only when the parameter
configuration cue has the first meaning, i.e. when, in a
multi-channel reconstruction, no configuration information
present in the decoder will be accessed in any way, but
when there is explicit signaling, i.e. when further

configuration information is present in the parameter data
set. In the other case, in which the parameter
configuration cue has the second meaning, the configuration
data writing means 15 is not activated to introduce data in
the parameter data set at the output 10, because such data
would not be read by a decoder and/or would not be required
by the decoder, as will be discussed later on. In the case
of a mixed solution, instead of signaling everything in the
data "stream, only a part of the configuration is signaled,
while the rest is taken, for example, from the
configuration table in the decoder.
The signaling means 14 includes a control input 18, via
which the signaling means 14 is informed of whether the
parameter configuration cue is to have the first or the
second meaning. As will be discussed with respect to Figs.
4a and 4b, in the so-called "synchronous" operation, it is
preferred to choose the parameter configuration cue so that
it has the second meaning to obtain information on the
coding algorithm in such a mode on the decoder side and to
make configuration settings in the multi-channel
reconstruction means on the decoder side depending thereon.
In the asynchronous operation, however, the control input
18 will drive the signaling means such that it determines
the first meaning for the parameter configuration cue,
which will be interpreted by a decoder such that there is
configuration information in the data themselves, and the
audio coding algorithm on which the transmission channel
data are based will not be used.
It is to be noted that the parameter data set and/or the
parameter data output do not have to be in a rigid form
with respect to each other. Thus, the configuration cue,
the configuration data and the parameter data do not
necessarily have to be transmitted together in a stream or
packet, but may also be provided to the decoder separately
from each other.

The following discussion will present the so-called
"synchronous" operation with respect to Fig. 4a. For the
purpose of illustration, Fig. 4a illustrates the parameter
data as a sequence of frames 40, wherein the sequence of
frames 40 is preceded by a header 41 in which there is the
parameter configuration cue generated by the signaling
means 14, and in which, if applicable, there is further
configuration information generated by the configuration
data writing means 15. The parameter data at the output of
means 11 are accommodated in the frames 1, 2, 3, 4, which
is the reason why they are also called payload data in Fig.
4a.
The continuation cue FSH, which is mentioned both in Fig. 1
at the output of the signaling means 14 and is further also
mentioned for the header 41 in Fig. 4a, causes a decoder to
maintain, i.e. continue, a configuration setting previously
communicated to the same, when it has a determined meaning,
while, when the continuation cue FSH has another meaning,
there is a decision on the basis of the parameter
configuration cue whether configuration settings will be
effected in the multi-channel reconstruction means based on
configuration information in the data stream or based on
configuration data retrieved by a cue to the audio coding
algorithm on the decoder side.
Fig. 4a further represents a sequence 42 of blocks of coded
transmission data in time association, which also have four
frames, frame 1, frame 2, frame 3, frame 4. The time
association of the parameter data with the coded
transmission channel data is illustrated by vertical arrows
in Fig. 4a. Thus, a block of coded transmission channel
data will always relate to a block of input data and/or,
when overlapping windows are used, at least the advance how
much data in a block are newly processed as compared to the
previous block will be laid down and, in synchronous
operation, will be synchronous with the block length and/or
the advance at which the parameter data are obtained. This

ensures that the connection between reconstruction
parameters on the one hand and transmission channel data on
the other hand is not lost.
This will be explained by means of a short example.
Assuming a 5-channel input signal, this 5-channel input
signal will have five different audio channels including
time samples from a time x to a time y, respectively. In
the downmix stage 114 of Fig. 6, at least one transmission
channel is then generated which will be synchronous with
the multi-channel input data. A portion of the transmission
channel data from time x to time y will thus correspond to
a portion of the respective multi-channel input data from
time x to time y. Furthermore, the BCC analysis means 116
of Fig. 6 generates, for example, parameter data, again
exactly for the time section of the transmission channel
data from time x to time y, so that, on the decoder side,
there may again be generated respective output channel data
from time x to time y from the transmission channel data
from time x to time y and the parameter data from time x to
time y.
A synchronous operation is automatically achieved when the
framing with which the parameter data are generated and
written is equal to the framing with which the audio
encoder operates for compressing the one or more
transmission channels. If thus the frames of both the
parameter data and the coded transmission channel data (40
and 42 in Fig. 4a) always relate to the same time portion,
a multi-channel reconstruction device may easily always
process data corresponding to an audio frame and process a
parameter frame at the same time.
In synchronous operation, the frame length of the audio
encoder used for the transmission of the downmix data is
thus equal to the frame length used by the parametric
multi-channel scheme. Similarly, there is of course also
the possibility that there is an integer relationship

between the frame lengths and the parameter data and the
coded transmission channel data. In this case, even the
side information for parametric multi-channel coding may be
multiplexed into the coded bit stream of the audio downmix
signal so that a single bit stream may be generated. In the
case of "retrofitting" already existing stereo data, there
would still be two different data streams. However, there
would be a relationship of 1:1 and/or m:l or m:n between
the two sequences of frames. The framing rasters would
never shift with respect to each other. Thus, there is an
unambiguous association between the audio data frames and
the corresponding parametric side information data frames.
This mode may be favorable for various applications.
According to the invention, the parameter configuration cue
would have the first meaning in such a case. This means
that there would be no or only part of the configuration
information in the header 41, because the multi-channel
reconstruction means provides itself with information on
the underlying audio encoder and, dependent thereon,
chooses its configuration setting, i.e. for example the
number of time samples for the advance or the block length,
etc.
In contrast, Fig. 4b shows an asynchronous operation. An
asynchronous operation exists when the transmission channel
data 42' do not, for example, have a frame structure, but
only occur as a stream of PCM samples. Alternatively, such
an asynchronous situation would also arise when the audio
encoder has an irregular frame structure or simply a frame
structure with a frame length and/or a frame raster
differing from the frame raster of the parameter data 40.
Here, the parametric multi-channel coding scheme and the
audio coding/decoding means are thus considered as isolated
and separate processing stages which do not depend on each
other. This is particularly advantageous in the case of so-
called tandem coding scenarios in which there are several
successive stages of coding/decoding. If the parameter data

were fixedly coupled to the compressed audio data, a multi-
channel synthesis and a subsequent multi-channel analysis
would have to be done simultaneously in each
coding/decoding. As these operations are lossy, the losses
would gradually accumulate, which would result in an
increasing deterioration of the multi-channel impression.
In such a tandem chain, the setting of the parameter
configuration cue to the second meaning and the writing of
configuration information into the data stream allow a
configuration setting of the multi-channel reconstruction
means in the decoder independently of the underlying audio
encoder. Downmix data may thus be decoded/coded in any way
without always having to perform a multi-channel synthesis
or multi-channel analysis at the same time. The
introduction of configuration information into the data
stream and preferably into the parameter data stream
according to the parameter data syntax allows, so to speak,
to lay down an absolute association of the parameter data
with time samples of the decoded transmission channel data,
i.e. an association that is self-sufficient and is not
given relative to an encoder frame processing rule, as in
synchronous operation.
In asynchronous operation, the deterioration of the multi-
channel sound characteristics is thus prevented, because
there is not always performed a multi-channel
analysis/synthesis. The frame size for the parametric
multi-channel coding/decoding thus does not necessarily
have to be connected to the frame size of the audio
encoder.
The device of Fig. 1 can be implemented both as encoder and
as so-called "forward transcoder". In the first case, the
multi-channel parameter means calculates the parameter data
itself. In the second case, it receives the parameter data
already in a determined form and provides the inventive
parameter data output with the parameter configuration cue

and associated configuration data. The forward transcoder
thus generates the inventive parameter data output from any
data output.
The reversal of this measure is done by a so-called
"backward transcoder" which, from the inventive parameter
data output, generates some output in which the parameter
configuration cue is no longer contained, in which,
however, the configuration data are also completely
contained, so that no use of an audio coding algorithm is
necessary in the multi-channel reconstruction for the
configuration.
According to the invention, the backward transcoder is
designed as device for generating a parameter data output
which, together with transmission channel data including M
transmission channels, represent N original channels,
wherein M is smaller than N and equal to or larger than 1,
using input data, wherein the input data comprise a
parameter configuration cue (41) that has a first meaning
that configuration information for a multi-channel
reconstruction means are contained in the input data, or
has a second meaning that the multi-channel reconstruction
means is to use configuration information depending on a
coding algorithm (23) with which the transmission channel
data have been decoded from a coded version thereof. It
contains a writing means for writing configuration data,
wherein the writing means is designed to first read the
input data to interpret (30) the parameter configuration
cue, and to retrieve information about a coding algorithm
(23) with which the transmission channel data have been
decoded from a coded version thereof and to output it as
the configuration data, when the parameter configuration
cue has the second meaning.
In the following, there will be described a block circuit
diagram of a device for generating a multi-channel audio
signal according to a preferred embodiment of the present

invention with respect to Fig. 2. For generating the multi-
channel audio signal, input data are used that include
transmission channel data representing the M transmission
channels and that further include parameter data 21 to
obtain K output channels. The M transmission channels and
the parameter data together represent N original channels,
wherein M is smaller than N and is equal to or larger than
1, and wherein K is larger than M. Furthermore, the input
data include a parameter configuration cue PKH, as already
discussed, while the transmission channel data 20 are a
decoded version of transmission channel data 22 coded
according to a coding algorithm. In the embodiment shown in
Fig. 2, the decoding algorithm is realized by an audio
decoder 2 3 having a coding algorithm operating, for
example, according to the MP3 concept or according to MPEG-
2 (AAC) or according to any other coding concept.
The device to be used on the decoder side shown in Fig. 2
includes a multi-channel reconstruction means 24 designed
to generate the K output channels at an output 25 from the
transmission channel data 20 and the parameter data 21.
Furthermore, the inventive device shown in Fig. 2 includes
configuration means 26 designed to configure the multi-
channel reconstruction means 24 by signaling a
configuration setting via a signaling line 27. The
configuration means 2 6 receives the input data and
preferably the parameter data 21 to read and
correspondingly process the parameter configuration cue,
the continuation cue FSH and possibly present configuration
data. Furthermore, the configuration means includes a
coding algorithm signaling input 28 to obtain information
about the audio coding algorithm on which the decoded
transmission channel data are based, i.e. the coding
algorithm executed by the audio encoder 23. The information
may be obtained in different ways, for example from an
observation of the decoded transmission channel data, if it
can be seen from them with which coding algorithm they have

been coded/decoded. Alternatively, the audio decoder 23 may
itself communicate its identity to the configuration means
26. Still alternatively, the configuration means 2 6 may
also parse the coded transmission channel data 22 to
determine a cue from the coded transmission channel data
according to which coding algorithm coding has taken place.
Such a "coding algorithm signature" will typically be
contained in each output data stream of an encoder.
In the following, a preferred implementation of the
configuration means will be described based on a block
diagram with respect to Fig. 3a. The configuration means 2 6
is designed to read the parameter configuration cue PKH
from the input data and to interpret it, as illustrated in
block 30. If the parameter configuration cue has a first
meaning, the configuration means will continue to read in
the parameter data stream to extract configuration
information (or at least part of the configuration
information) in the parameter data stream, as illustrated
in block 31. If, however, step 30 determines that the
parameter configuration cue PKH has the second meaning, the
configuration means will obtain information on a coding
algorithm on which the decoded transmission channel data
are based, in step 32.
If there are several basically possible coding algorithms
for which the inventive device for generating the multi-
channel signal is designed, step 32 is followed by a
subsequent step 33 in which the multi-channel
reconstruction means determines (33) a configuration
setting based on information existing on the decoder side.
This may be done, for example, in the form of a look-up
table (LUT) . If, at the end of step 32, an audio encoder
identification cue is obtained, a look-up table is entered
in step 33 using the audio encoder identification cue,
wherein the audio encoder identification cue is used as
index. Associated in the index there are found various

configuration settings, such as block length, sampling
rate, advance, etc. associated with such an audio encoder.
A configuration setting is then applied to the multi-
channel reconstruction means in step 34. If, however, the
first meaning of the parameter configuration cue is chosen
in step 30, the same configuration setting is effected
based on configuration information contained in the
parameter data stream, as represented by the connecting
arrow between block 31 and block 34 in Fig. 3.
The inventive scheme is flexible in that it supports both
explicit and implicit configuration information signaling
methods. This is what the parameter configuration cue PKH
serves for, which is preferably inserted as flag and, in
the best case, requires only a single bit to indicate the
signaling of the configuration information per se. The
parametric multi-channel decoder may subsequently evaluate
this flag. If the availability of explicitly available
configuration information is signaled with this flag, this
configuration information is used. If, on the other hand,
implicit signaling is indicated by the flag, the decoder
will use the information on the used audio or voice coding
method and apply configuration information based on the
signaled coding method. For this purpose, the parametric
multi-channel decoder and/or the multi-channel
reconstruction means preferably has a look-up table
containing the standard configuration information for a
determined number of audio or voice encoders. There are,
however, also other possibilities than a look-up table
which may, for example, include hard-wired solutions, etc.
Generally, the decoder is capable of providing the
configuration information with predetermined information
present in itself depending on the actually present encoder
identification information.
This concept is particularly advantageous in that a
complete configuration of the parameter scheme may be

achieved with a minimum of additional effort, wherein, in
the extreme case, a single bit will be sufficient, which
forms a contrast to the situation that all configuration
information would have to be written explicitly into the
data stream itself with a considerably higher effort
regarding bits.
According to the invention, the signaling may be switched
back and forth. This allows simple multi-channel data
handling, even if the representation of the transmission
channel data changes, for example when the transmission
channel data are decoded and later coded again, i.e. when
there is a tandem coding situation.
The inventive concept thus allows the saving of signaling
bits in the case of synchronous operation on the one hand
and switching to asynchronous operation on the other hand,
if necessary, i.e. an efficient bit-saving implementation
and, on the other hand, flexible handling, which will be of
particular interest in connection with the
"supplementation" of existing stereo data to a multi-
channel representation.
In the following, there will be given an exemplary
implementation of the inventive device for generating a
multi-channel audio signal with the example of a syntax
pseudo code, with respect to Fig. 4c. First, the value of
the variable "useSameBccConfig" is read in. Here, the
variable serves as continuation cue. So, there is only a
continuation to interpret the parameter configuration cue
when this variable, i.e. the continuation cue, has a value
equal to, for example, 1. If, however, the continuation cue
is unequal to 1, i.e. it has the other meaning, a
previously transmitted configuration is used. If there is
no configuration in the multi-channel reconstruction means
yet, it has to wait until it obtains the very first
configuration information and/or configuration setting.

The following will examine the parameter configuration cue.
The variable "codecToBccConfigAlignment" serves as
parameter configuration cue PKH. If this variable is equal
to 1, i.e. if it has the second meaning, the decoder will
not use any further configuration information, but will
determine the configuration information based on the
encoder identification, such as MP3, CoderX or CoderY, as
can be seen from the lines starting with "case" in Fig. 4c.
It is to be noted that, by way of example, the syntax shown
in Fig. 4c only supports MP3, CoderX and CoderY. However,
any other coding names/identifications may be added.
When, for example, MP3 has been determined as encoder
information, the variable bccConfigID is set to, for
example, MP3_V1, which is the configuration for an
underlying MP3 encoder with the syntax version VI.
Subsequently, the decoder is configured with a determined
parameter set based on this BCC configuration
identification. Thus, for example, a block length of 576
samples is activated as configuration setting. Thus, a
framing having this block length is signaled.
Alternative/additional configuration settings may be the
sampling rate, etc. If, however, the parameter
configuration cue (codecToBccConfigAlignment) has the first
meaning, i.e. for example the value 0, the decoder will
explicitly receive configuration information from the data
stream, i.e. it will receive a distinct bccConfigID from
the data stream, i.e. from the input data. The following
procedure is then the same as just described. In this case,
however, an identification of the decoder for decoding the
coded transmission channel data is not used for
configuration purposes of the multi-channel reconstruction
means.
Thus, the bccConfigID may be used for the purpose of
decoding the transmission channel data in the case of an
MP3 audio decoder for configuring a multi-channel
reconstruction means. On the other hand, there may also be

any other configuration information bccConfigID in the data
stream and may be evaluated, irrespective of whether or not
the underlying audio encoder is an MP3 encoder. The same
applies to other predefined configuration settings, such as
CoderX and CoderY, and to a further free configuration in
which the configuration information (bccConfiglD) is set to
individual. In preferred embodiments, there are further
configuration information in the data stream which, in
turn, signal to the decoder that it should use a mixture of
already predefined configuration information present in the
decoder and explicitly transmitted configuration
information.
Unlike the above-described embodiments, the present
invention may also be applied to other multi-channel
signals which are no audio signals, such as parametrically
coded video signals, etc.
Depending on the circumstances, the inventive method for
generating and/or decoding may be implemented in hardware
or in software. The implementation may be done on a digital
storage medium, in particular a floppy disk or CD having
control signals that may be read out electronically, which
may cooperate with a programmable computer system so that
the method is executed. In general, the invention thus also
consists in a computer program product having a program
code for performing the method stored on a machine-readable
carrier, when the computer program product runs on a
computer. In other words, the invention may thus be
realized as a computer program having a program code for
performing the method, when the computer program runs on a
computer.

We Claim:
1. Device for generating a multi-channel signal using input data which comprises
transmission channel data representing M transmission channels and
parameter data to obtain K output channels, wherein the M transmission
channels and the parameter data together represent N original channels,
wherein M is less than N and equal to or larger than 1, and wherein K is larger
than M, wherein the input data comprise a parameter configuration cue (41),
comprising:
multi-channel reconstruction means (24) designed to generate the K output
channels from the transmission channel data and the parameter data; and
configuration means (26) for configuring the multi-channel reconstruction
means, wherein the configuration means is designed to read the input data
to interpret (30) the parameter configuration cue,
when the parameter configuration cue has a first meaning, extract (31)
configuration information contained in the input data and effect (34) a con-
figuration setting of the multi-channel reconstruction means, and
when the parameter configuration cue has a second meaning differing from
the first meaning, configure (34) the multi-channel reconstruction means
using information on a coding algorithm (23) with which the transmission
channel data have been decoded from a coded version thereof so that the

configuration setting of the multi channel reconstruction means is identical to
a configuration setting of the coding algorithm (23) or depends on a
configuration setting of the coding algorithm (23).
2. Device as claimed in claim 1, wherein the transmission channel data comprise
a transmission channel 55 data stream having a transmission channel data syn-
tax,
wherein the parameter data comprise a parameter data stream having a
parameter data syntax, wherein the transmission channel data syntax differs
from the parameter data syntax, and
wherein the parameter configuration cue is inserted in the parameter data
according to this syntax, wherein the configuration means (26) is designed to
read the parameter data according to the parameter data syntax and to
extract (30) the parameter configuration cue.
3. Device as claimed in claim 1 or 2, wherein the multichannel reconstruction
means (24) is designed to perform processing in blocks, wherein the transmis-
sion channel data are a sequence of samples, and wherein the configuration
setting includes a block length or an advance number of samples which are
newly processed by the multi-channel reconstruction means (24) per
processing of a block.

4. Device as claimed in claim 3, wherein the transmission channel data are time
samples of the at least one transmission channel, and the multi-channel re-
construction means (24) comprises a filter bank to convert a block of time
samples of the transmission channel data to a frequency domain
representation.
5. Device as claimed in one of the preceding claims, wherein the parameter data
comprise a sequence of blocks of parameter values, wherein a block of
parameter values is associated with a time portion of the at least one
transmission channel, wherein the multi-channel reconstruction means (24) is
designed so that the configuration setting causes the block of parameter
values and the associated time portion of the at least one transmission channel
to be used for generating the K output channels.
6. Device as claimed in one of the preceding claims, wherein the coding algorithm
(23) is one from among a plurality of various coding algorithms, and
wherein the configuration means (26) comprises look-up table means which
includes an index and a set of configuration information associated with the
indexforacoding algorithm, which respectively comprise the configuration setting
for the coding algorithms,

wherein the configuration means (26) is designed to determined the index for
the look-up table from the information on the coding algorithm and to determine
(33) therefrom the configuration information for the multi-channel reconstruction
means.
7. Device as claimed in one of the preceding claims, wherein the input data
comprise configuration information for the multi-channel reconstruction means
(24) in the case of a parameter configuration cue having the first meaning, and
comprise only part of or no configuration information for the multi-channel
reconstruction means in the case of the parameter configuration cue having
the second meaning.
8. Device as claimed in one of the preceding claims, wherein the configuration
means (26) is designed to extract only part of required configuration informa-
tion from the input data when the parameter configuration cue has the second
meaning, and to use a remaining part of configuration information from the
preset configuration information known to the multichannel reconstruction
means.

9. Device as claimed in one of the preceding claims, wherein the configuration
means (26) is designed to obtain the information on the coding algorithm via a
connecting line via which the configuration means may be connected to a
decoder which generates the transmission channel data from the coded
transmission channel data, orto obtain the information on the coding algorithm
by reading the transmission channel data or the coded transmission channel
data, when the parameter configuration cue has the second meaning.
10. Device as claimed in one of the preceding claims, wherein the input data
comprise a continuation cue (41), and
wherein the configuration means (26) is designed to read and interpret (29)
the continuation cue to effect a fixedly set or previously signaled
configuration setting of the multi-channel reconstruction means in a case of
the continuation cue having a first meaning, and to configure (30) the multi-
channel reconstruction means on the basis of the parameter configuration
cue only in the case of the continuation cue having a second meaning
differing from the first meaning.
11. Device as claimed in claim 10, wherein the continuation cue is associated with
the parameter data according to a parameter data syntax and is a flag in the
parameter data stream.

12. Device as claimed in one of the preceding claims, wherein the parameter
configuration cue is associated with the parameter data according to a param-
eter data syntax and is a flag in the parameter data stream.
13. Device as claimed in claim 11 or 12, wherein the continuation cue or the
parameter configuration cue each comprises a single bit.
14. Method for generating a multi-channel signal using input data which icomprise
transmission channel data representing M transmission channels and parame-
ter data to obtain K output channels, wherein the M transmission channels and
the parameter data together represent N original channels, wherein M is less
than N and equal to or larger than 1, and wherein K is larger than M, wherein
the input data comprise a parameter configuration cue (41), comprising:
reconstructing (24) the K output channels from the transmission channel data
and the parameter data according to a reconstruction algorithm;
configuring (26) the reconstruction algorithm by the following sub-steps:
reading the input data to interpret (30) the parameter configuration cue;

when the parameter configuration cue has a first meaning, extracting (31)
configuration information contained in the input data and effecting (34) a
configuration setting of the reconstruction algorithm, and
when the parameter configuration cue has a second meaning differing from the
first meaning, effecting (34) the configuration setting of the reconstruction
algorithm using information on a coding algorithm (23) with which the
transmission channel data have been decoded from a coded version thereof, so
that the configuration setting is identical to a configuration setting of the coding
algorithm (23) or depends on a configuration setting of the coding algorithm
(23).
15. Device for generating a parameter data output which, together with
transmission channel data including M transmission channels, represent N orig-
inal channels, wherein M is less than N and is equal to or larger than 1,
comprising:
multi-channel parameter means (11) for providing the parameter data;
signaling means (14) for determining a parameter configuration cue, wherein
the parameter configuration cue has a first meaning when configuration
information contained in the parameter data output is to be used for a multi-
channel reconstruction means, and wherein the parameter configuration cue

has a second meaning when configuration data are to be used for a multi-
channel reconstruction which are based on a coding algorithm to be used for
coding or decoding the M transmission channels; and
configuration data writing means (15) for output-ting the configuration
information to obtain the parameter data output.
16. Device as claimed in claim 15, wherein the configuration data writing means
(15) is designed to insert a continuation cue into the parameter data set,
wherein the continuation cue causes a fixedly set previously signaled
configuration setting to be used
in a multi-channel reconstruction when it has a first meaning, and causes
that a configuration of a multichannel reconstruction is to take place using
the parameter configuration cue when the continuation cue has a second
meaning differing from the first meaning.
17. Device as claimed in claim 15 or 16, wherein the configuration data writing
means is designed to associate no or only part of necessary configuration infor-
mation with the parameter data set when the parameter configuration cue has
the second meaning (17).

18. Method for generating a parameter data output which, together with
transmission channel data comprising M transmission channels, represent N
original channels, wherein M is less than N and is equal to or larger than 1,
comprising:
providing (11) the parameter data;
determining (14) a parameter configuration cue, wherein the parameter
configuration cue has a first meaning when configuration information
contained in the parameter data output is to be used for a multi-channel
reconstruction algorithm, and wherein the parameter configuration cue has a
second meaning when configuration data are to be used for a multi-channel
reconstruction which are based on a coding algorithm to be used for coding
or decoding the M transmission channels; and
outputting (15) the configuration information to obtain the parameter data
output.



ABSTRACT


TITLE: Device and Method for Reconstruction of Multi-channel Audio Signal for
Generating A Parameter DataCert
The invention relates to a device for generating a multi-channel signal using input
data which comprises transmission channel data representing M transmission
channels and parameter data to obtain K output channels, wherein the M
transmission channels and the parameter data together represent N original
channels, wherein M is less than N and equal to or larger than 1, and wherein K is
larger than M, wherein the input data comprise a parameter configuration cue (41),
comprising multi-channel reconstruction means (24) designed to generate the K
output channels from the transmission channel data and the parameter data; and
configuration means (26) for configuring the multi-channel reconstruction means,
wherein the configuration means is designed to read the input data to interpret (30)
the parameter configuration cue, when the parameter configuration cue has a first
meaning, extract (31) configuration information contained in the input data and
effect (34) a configuration setting of the multi-channel reconstruction means, and
when the parameter configuration cue has a second meaning differing from the first
meaning, configure (34) the multi-channel reconstruction means using information
on a coding algorithm (23) with which the transmission channel data have been
decoded from a coded version thereof so that the configuration setting of the multi -
channel reconstruction means is identical to a configuration setting of the coding
algorithm (23) or depends on a configuration setting of the coding algorithm (23).

Documents:

00779-kolnp-2007 correspondence-1.1.pdf

00779-kolnp-2007 form-26.pdf

00779-kolnp-2007-correspondence-1.1.pdf

00779-kolnp-2007-correspondence-1.2.pdf

00779-kolnp-2007-form-18.pdf

00779-kolnp-2007-international search authority.pdf

00779-kolnp-2007-priority document.pdf

0779-kolnp-2007-abstract.pdf

0779-kolnp-2007-claims.pdf

0779-kolnp-2007-correspondence others.pdf

0779-kolnp-2007-description (complete).pdf

0779-kolnp-2007-drawings.pdf

0779-kolnp-2007-form1.pdf

0779-kolnp-2007-form2.pdf

0779-kolnp-2007-form3.pdf

0779-kolnp-2007-form5.pdf

0779-kolnp-2007-international publication.pdf

779-KOLNP-2007-(01-04-2013)-ABSTRACT.pdf

779-KOLNP-2007-(01-04-2013)-CLAIMS.pdf

779-KOLNP-2007-(01-04-2013)-CORRESPONDENCE.pdf

779-KOLNP-2007-(01-04-2013)-FORM 1.pdf

779-KOLNP-2007-(01-04-2013)-FORM 2.pdf

779-KOLNP-2007-(19-03-2012)-CORRESPONDENCE.pdf

779-KOLNP-2007-ABSTRACT 1.1.pdf

779-KOLNP-2007-AMANDED CLAIMS.pdf

779-KOLNP-2007-AMANDED PAGES OF SPECIFICATION.pdf

779-KOLNP-2007-CORRESPONDENCE.pdf

779-KOLNP-2007-DESCRIPTION (COMPLETE) 1.1.pdf

779-KOLNP-2007-DRAWINGS 1.1.pdf

779-KOLNP-2007-EXAMINATION REPORT REPLY RECIEVED.pdf

779-KOLNP-2007-EXAMINATION REPORT.pdf

779-KOLNP-2007-FORM 1-1.1.pdf

779-KOLNP-2007-FORM 18.pdf

779-KOLNP-2007-FORM 2-1.1.pdf

779-KOLNP-2007-FORM 26.pdf

779-KOLNP-2007-FORM 3-1.1.pdf

779-KOLNP-2007-FORM 5-1.1.pdf

779-KOLNP-2007-GRANTED-ABSTRACT.pdf

779-KOLNP-2007-GRANTED-CLAIMS.pdf

779-KOLNP-2007-GRANTED-DESCRIPTION (COMPLETE).pdf

779-KOLNP-2007-GRANTED-DRAWINGS.pdf

779-KOLNP-2007-GRANTED-FORM 1.pdf

779-KOLNP-2007-GRANTED-FORM 2.pdf

779-KOLNP-2007-GRANTED-FORM 3.pdf

779-KOLNP-2007-GRANTED-FORM 5.pdf

779-KOLNP-2007-GRANTED-SPECIFICATION-COMPLETE.pdf

779-KOLNP-2007-INTERNATIONAL PUBLICATION.pdf

779-KOLNP-2007-INTERNATIONAL SEARCH REPORT & OTHERS.pdf

779-KOLNP-2007-OTHERS.pdf

779-KOLNP-2007-TRANSLATED COPY OF PRIORITY DOCUMENT.pdf

abstract-00779-kolnp-2007.jpg


Patent Number 257413
Indian Patent Application Number 779/KOLNP/2007
PG Journal Number 40/2013
Publication Date 04-Oct-2013
Grant Date 30-Sep-2013
Date of Filing 05-Mar-2007
Name of Patentee FRAUNHOFER-GESELLSCHAFT ZUR FORDERUNG DER ANGEWANDTEN FORSCHUNG E.V.
Applicant Address HANSASTRASSE 27 C 80686 MUNCHEN
Inventors:
# Inventor's Name Inventor's Address
1 HILPERT, JOHANNES HERRNHÜTTESTRASSE 46 90411 NÜRNBERG.
2 GEYERSBERGER, STEFAN OTTO-ROTH-STRASSE 90 97076 WÜRZBURG.
3 SPERSCHNEIDER, RALPH DONATO-POLLI-STRASSE 42 91056 ERLANGEN
4 ERTEL, CHRISTIAN GARTENSTRASSE 15 91338 LGENSDORF.
5 HERRE, JÜRGEN HALLERSTRASSE 24 91054 BUCKENHOF.
PCT International Classification Number G10L 19/00
PCT International Application Number PCT/EP2005/008694
PCT International Filing date 2005-08-10
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 102004043521.9 2004-09-08 Germany