Title of Invention

AN APPARATUS AND A METHOD FOR RECONSTRUCTING A MULTI-CHANNEL SIGNAL USING AT LEAST ONE BASE CHANNEL AND A PARAMETRIC REPRESENTATION

Abstract The invention relates to an apparatus for reconstructing a multi-channel signal using at least one base channel and a parametric representation comprising direction parameter information indicating a direction from a reference position in a replay setup to a region in the replay setup, wherein a combined sound energy of at least three original channels is concentrated, from which the at least one base channel has been derived, and comprising a balance parameter, the apparatus comprising: an output channel generator for generating a number of output channels to be positioned in the replay setup with respect to the reference position, the number of output channels being higher than the number of base channels, wherein the output channel generator is configured to generate the output channels in response to the direction parameter information so that the direction from the reference position to the region, wherein the combined energy of the reconstructed output channels is concentrated depends on the direction indicated by the direction parameter information, wherein the output channel generator is configured to select a pair of output channels using the direction parameter to obtain a selected pair of output channels, the direction parameter comprising information on a pair of output channels as a direction from a reference position in a replay setup to a region in the replay setup, wherein a combined sound energy of at least three original channels is concentrated, wherein the output channel generator is configured to calculate audio signals for the selected pair of output channels using the balance parameter indicating a balance between the selected pair of output channels such that an energy distribution between the selected pair of output channels is determined by the balance parameter, and wherein the output channel generator is configured to calculate one or more ambience channel signals for one or more channels not included in the selected pair of output channels, wherein the output channel generator comprises a hardware implementation.
Full Text


FIELD OF THE INVENTION
The present invention relates to coding of multi-channel representations of audio
signals using spatial parameters. The invention teaches new methods for
defining and estimating parameters for recreating a multi-channel signal from a
number of channels being less than the number of output channels. In particular
it aims at minimizing the bitrate for the multi-channel representation, and
providing a coded representation of the multi-channel signal enabling easy
encoding and decoding of the data for all possible channel configurations.
BACKGROUND OF THE INVENTION
With a growing interest for multi-channel audio in e.g. broadcasting systems, the
demand for a digital low bitrate audio coding technique is obvious. It has been
shown in PCT/SE02/01372 "Efficient and scalable Parametric Stereo Coding for
Low Bitrate Audio Coding Applications", that it is possible to re-create a stereo
image that closely resembles the original stereo image, from a mono downmix
signal and an additional very compact parametric representation of the stereo
image. The basic principle is to divide the input signal into- frequency bands and
time segments, and for these frequency bands and time segments, estimate
inter-channel intensity difference (IID), and inter-channel coherence (ICC), the
first parameter being a measurement of the power distribution between the two
channels in the specific frequency band and the second parameter being an
estimation of the correlation between the two channels for the specific frequency
band. On the

decoder side the stereo image is recreated from the mono
signal by distributing the mono signal between the two
output channels in accordance with the transmitted IID-
data, and by adding a decorrelated ambience signal in order
to retain the channel correlation properties of the
original stereo channels.
Several matrixing techniques exist that create multi-
channel output from stereo signals. These techniques often
rely on phase differences to create the back channels.
Often, the back channels are delayed slightly compared to
the front channels. To maximise performance the stereo file
is created using special down mixing rules on the encoder
side from a multi-channel signal to two stereo base
channels. These systems generally have a stable front sound
image with some ambience sound in the back channels and
there is a limited ability to separate complex sound
material into different speakers.
Several multi-channel configurations exist. The most
commonly known configuration is the 5.1 configuration
(centre channel, front left/right, surround left/right, and
the LFE channel). ITU-R BS.775 defines several down-mix
schemes for obtaining a channel configuration comprising
fewer channels than a given channel configuration. Instead
of always having to decode all channels and rely on a down-
mix, it can be desirable to have a multi-channel
representation that enables a receiver to extract the
parameters relevant for the playback channel configuration
at hand, prior to decoding the channels. Another
alternative is to have parameters that can map to any
speaker combination at the decoder side. Furthermore, a
parameter set that is inherently scaleable is desirable
from a scalable or embedded coding point of view, where it
is e.g. possible to store the data corresponding to the
surround channels in an enhancement layer in the bitstream.

Another representation of multi-channel signals using a sum
signal or down mix signal and additional parametric side
information is known in the art as binaural cue coding
(BCC). This technique is described in "Binaural Cue Coding
Part 1: Psycho-Acoustic Fundamentals and Design
Principles", IEEE Transactions on Speech and- Audio
Processing, vol. 11, No. 6, November 2003, F. Baumgarte,
C. Faller, and "Binaural Cue Coding. Part II: Schemes and
Applications", IEEE Transactions on Speech and Audio
Processing vol. 11, No. 6, November 2003, C. Faller and
F. Baumgarte.
Generally, binaural cue coding is a method for multi-
channel spatial rendering based on one down-mixed audio
channel and side information. Several parameters to be
calculated by a BCC encoder and to be used by a BCC decoder
for audio reconstruction or audio rendering include inter-
channel level differences, inter-channel time differences,
and inter-channel coherence parameters. These inter-channel
cues are the determining factor for the perception of a
spatial image. These parameters are given for blocks of
time samples of the original multi-channel signal and are
also given frequency-selective so that each block of multi-
channel signal samples have several cues for several
frequency bands. In the general case of C playback
channels, the inter-channel level differences and the
inter-channel time differences are considered in each
subband between pairs of channels, i.e., for each channel
relative to a reference channel. One channel is defined as
the reference channel for each inter-channel level
difference. With the inter-channel level differences and
the inter-channel time differences, it is possible to
render a source to any direction between one of the
loudspeaker pairs of a playback set-up that is used. For
determining the width or diffuseness of a rendered source,
it is enough to consider one parameter per subband for all
audio channels. This parameter is the inter-channel
coherence parameter. The width of the rendered source is

controlled by modifying the subband signals such that all
possible channel pairs have the same inter-channel
coherence parameter.
In 3CC coding, all inter-channel level differences are
determined between the reference channel 1 and any other
channel. When, for example, the centre channel is
determined to be the reference channel, a first inter-
channel level difference between the left channel and the
centre channel, a second inter-channel level difference
between the right channel and the centre channel, a third
inter-channel level difference between the left surround
channel and the centre channel, and a forth inter-channel
level difference between the right surround channel and the
centre channel are calculated. This scenario describes a
five-channel scheme. When the five-channel scheme
additionally includes a low frequency enhancement channel,
which is also known as a "sub-woofer" channel, a fifth
inter-channels level difference between the low frequency
enhancement channel and the centre channel, which is the
single reference channel, is calculated.
When reconstructing the original multi-channel using the
single down mix channel, which is also termed as the "mono"
channel, and the transmitted cues such as ICLD
(Interchannel Level Difference), ICTD (Interchannel Time
Difference), and ICC (Interchannel Coherence), the spectral
coefficients of the mono signal are modified using these
cues. The level modification is performed using a positive
real number determining the level modification for each
spectral coefficient. The inter-channel time difference is
generated using a complex number of magnitude of one
determining a phase modification for each spectral
coefficient. Another function determines the coherence
influence. The factors for level modifications of each
channel are computed by firstly calculating the factor for
the reference channel. The factor for the reference channel
is computed such that for each frequency partition, the sum

of the power of all channels is the same as the power of
the sum signal. Then, based on the level modification
factor for the reference channel, the level modification
factors for the other channels are calculated using the
respective ICLD parameters.
Thus, in order to perform BCC synthesis, the level
modification factor for the reference channel is to be
calculated. For this calculation, all ICLD parameters for a
frequency band are necessary. Then, based on this level
modification for the single channel, the level modification
factors for the other channels, i.e., the channels, which
are not the reference channel, can be calculated.
This approach is disadvantageous in that, for a perfect
reconstruction, one needs each and every inter-channel
level difference. This requirement is even more
problematic, when an error-prone transmission channel is
present. Each error within a transmitted inter-channel
level difference will result in an error in the
reconstructed multi-channel signal, since each inter-
channel level difference is required to calculate each one
of the multi-channel output signal. Additionally, no
reconstruction is possible, when an inter-channel level
difference has been lost during transmission, although this
inter-channel level difference was only necessary for e.g.
the left surround channel or the right surround channel,
which channels are not so important to multi-channel
reconstruction, since most of the information is included
in the front left channel, which is subsequently called the
left channel, the front right channel, which is
subsequently called the right channel, or the centre
channel. This situation becomes even worse, when the inter-
channel level difference of the low frequency enhancement
channel has been lost during transmission. In this
situation, no or only an erroneous multi-channel
reconstruction is possible, although the low frequency
enhancement channel is not so decisive for the listeners'

listening comfort. Thus, errors in a single inter-channel
level difference are propagated to errors within each of
the reconstructed output channels.
While such multi-channel parameterization schemes are based
on the intention to fully reconstruct the energy
distribution, the price one has to pay for this correct
reconstruction of the energy distribution is an increased
bit rate, since a lot of inter-channel level differences or
balance parameters for the spatial energy distribution have
to be transmitted. Although these energy distribution
schemes naturally do not perform an exact reconstruction of
time wave forms of the original channels, they nevertheless
result in a sufficient output channel quality because of
the exact energy distribution property.
For low-bit rate applications, however, these schemes still
require too many bits, which has resulted in the
consequence that for such low-bit rate applications, one
did not think of a multi-channel reconstruction but one was
satisfied with having a mono or stereo reconstruction only.
SUMMARY OF THE INVENTION
It is the object of the present invention to provide a
multi-channel processing scheme, which allows a multi-
channel reconstruction even under low-bit rate constraints.
This object is achieved by an apparatus for generating a
parametric representation in accordance with claim 1, an
apparatus for reconstructing a multi-channel signal in
accordance with claim 19, a method of generating a
parametric representation in accordance with claim 28, a
method of reconstructing a multi-channel signal in
accordance with claim 29, a computer program in accordance
with claim 30 or a parameter representation in accordance
with claim 31.

The present invention is based on the finding that the main
subjective auditory feeling of a listener of a multi-
channel representation is generated by her or him
recognizing the specific region/direction in a replay
setup, in which the sound energy is concentrated. This
region/direction can be located by a listener within
certain accuracy. Not so important for the subjective
listening impression is, however, the distribution of the
sound energy between the respective speakers. When, for
example, the concentration of the sound energy of all
channels is within a sector of the replay setup, which
extends between a reference point, which preferably is the
center point of a replay setup, and two speakers, it is not
so important for the listener's subjective quality
impression, how the energy is distributed between the other
speakers. When comparing a reconstructed multi-channel
signal to an original multi-channel signal, it has been
found out that the user is satisfied to a high degree, when
the concentration of the sound energy within a certain
region in the reconstructed sound field is similar to the
corresponding situation of the original multi-channel
signal.
In view of this, it becomes clear that prior art parametric
multi-channel schemes process and transmit an amount of
redundant information, since such schemes have concentrated
on encoding and transmitting the complete distribution
between all channels in a replay setup.
In accordance with the present invention, only the region
including the local sound energy maximum is encoded, while
the distribution of energy between other channels, which do
not have main contributions to this local maximum sound
energy, is neglected and, therefore, does not involve any
bits for transmitting this information. Thus, the present
invention encodes and transmits even less information from
a sound field compared to prior art full-energy

distribution systems and, therefore, also allows a multi-
channel reconstruction even under very restrictive bit rate
conditions.
Stated in other words, the present invention determines the
direction of the local sound maximum region with respect to
a reference position and, based on this information, a sub-
group of speakers such as the speakers defining a sector,
in which the sound maximum is positioned or two speakers
surrounding the sound-maximum, is selected on the decoder-
side. This selection only uses transmitted direction
information for the maximum energy region. On the decoder-
side, the energy of the signals in the selected channels is
set such that the local sound maximum region is
reconstructed. The energies in the selected channels can -
and will necessarily be - different from the energies of
the corresponding channels in the original multi-channel
signal. Nevertheless, the direction of the local sound
maximum is identical to the direction of the local maximum
in the original signal or is at least quite similar. The
signals for the remaining channels will be created
synthetically as ambience signals. The ambience signals are
also derived from the transmitted base channel (s), which
typically will be a mono channel. For generating the
ambience channels, however, the present invention does not
necessarily need any transmitted information. Instead,
decorrelated signals for the ambience channels are derived
from the mono signals such as by using a reverberator or
any other known device for generating decorrelated signal.
For making sure that the combined energy of the selected
channels and the remaining channels is similar to the mono
signal or the original signal, a level control is
performed, which scales all signals in the selected
channels and the remaining channels such that the energy
condition is fulfilled. This scaling of all channels,
however, does not result in a moving of the energy maximum
region, since this energy maximum region is determined by a

transmitted direction information, which is used for
selecting the channels and for adjusting the energy ratio
between the energies in the selected channels.
Subsequently, two preferred embodiments are summarized. The
present invention relates to the problem of a parameterized
multi-channel representation of audio signals. One
preferred embodiment includes a method for encoding and
decoding sound positioning within a multi-channel audio
signal, comprising: down-mixing the multi-channel signal on
the encoder side, given said multi-channel signal;
selecting a channel pair within the multi-channel signal;
at the encoder, calculating parameters for positioning a
sound between said selected channels; encoding said
positioning parameters and said channel pair selection; at
the decoder side, recreating multi-channel audio according
to said selection and positioning parameters decoded from
bitstream data.
A further embodiment includes a method for encoding and
decoding sound positioning within a multi-channel audio
signal, comprising: down-mixing the multi-channel signal on
the encoder side, given said multi-channel signal;
calculating an angle and a radius that represent said
multi-channel signal; encoding said angle and said radius;
at the decoder side, recreating multi-channel audio
according to said angle and said radius decoded from the
bitstream data.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The present invention will now be described by way of
illustrative examples, not limiting the scope or spirit of
the invention, with reference to the accompanying drawings,
in which:

Fig. 1a illustrates a possible signalling for a route &
pan parameter system;
Fig. 1b illustrates a possible signalling for a route &
pan parameter system;
Fig. 1c illustrates a possible signalling for a route &
pan parameter system;
Fig. 1d illustrates a possible block diagram for a route
& pan parameter system decoder;
Fig. 2 illustrates a possible signalling table for a
route & pan parameter system;
Fig. 3a illustrates a possible two channel panning;
Fig. 3b illustrates a possible three channel panning;
Fig. 4a illustrates a possible signalling for an angle
and radius parameter system;
Fig. 4b illustrates a possible signalling for an angle
and radius parameter system;
Fig. 5a illustrates a block diagram of an inventive
apparatus for generating a parametric
representation of an original multi-channel
signal;
Fig. 5b indicates a schematic block diagram of an
inventive apparatus for reconstructing a multi-
channel signal;
Fig. 5c illustrates a preferred embodiment of the output
channel generator of Fig. 5b;

Fig. 6a shows a general flow chart of the route and pan
embodiment; and
Fig. 6b shows a flow chart of the preferred angle and
radius embodiment.
DESCRIPTION OF PREFERRED EMBODIMENTS
The below-described embodiments are merely illustrative for
the principles of the present invention on multi-channels
representation of audio signals. It is understood that
modifications and variations of the arrangements and the
details described herein will be apparent to others skilled
in the art. It is the intent, therefore, to be limited only
by the scope of the impending patent claims and not by the
specific details presented by way of description and
explanation of the embodiments herein.
A first embodiment of the present invention, hereinafter
referred to as 'route & pan', uses the following parameters
to position an audio source across the speaker array:
a panorama parameter for continuously positioning the
sound between two (or three) loudspeakers; and
routing information defining the speaker pair (or
triple) the panorama parameter applies to.
Figs. 1a through 1c illustrate this scheme, using a typical
five loudspeaker setup comprising of a left front channel
speaker (L), 102, 111 and 122, a centre channel speaker
(C) , 103, 112 and 123, a right front channel speaker (R) ,
104, 113 and 124, a left surround channel speaker (Ls) 101,
110 and 121 and a right surround channel speaker (Rs) 105,
114 and 125. The original 5 channel input signal is
downmixed at an encoder to a mono signal which is coded,
transmitted or stored.

In the example in Fig. la, the encoder has determined that
the sound energy basically is concentrated to 104 (R) and
105 (Rs). Thus, the channels 104 and 105 have been selected
as the speaker pair which the panorama parameter is applied
to. The panorama parameter is estimated, coded and
transmitted in accordance with prior art methods. This is
illustrated by the arrow 107, which defines the limits for
positioning a virtual sound source at this particular
speaker pair selection. Similarly, an optional stereo width
parameter can be derived and signalled for said channel
pair in accordance with prior art methods. The channel
selection can be signalled by means of a three bit 'route'
signal, as defined by the table in Fig. 2. PSP denotes
Parametric Stereo Pair, and the second column of the table
lists which speakers to apply the panning and optional
stereo width information at a given value of the route
signal. DAP denotes Derived Ambience Pair, i.e. a stereo
signal which is obtained by processing the PSP with
arbitrary prior art methods for generating ambience
signals. The third column of the table defines which
speaker pair to feed with the DAP signal, the relative
level of which is either predefined or optionally signalled
from the encoder by means of an ambience level signal.
Route values of 0 through 3 correspond to turning around a
4 channel system (disregarding the centre channel speaker
(C) for now) , comprising of a PSP for the "front" channels
and DAP for the "back" channels in 90 degree steps
(approximately, depending on the speaker array geometry).
Thus Fig la corresponds to route value 1, and 106 defines
the spatial coverage of the DAP signal. Clearly this method
allows for moving sound objects 360 degrees around the room
by selecting speaker pairs corresponding to route values 0
through 3.
Fig. 1d is a block diagram of one possible embodiment of a
route and pan decoder comprising of a parametric stereo
decoder according to prior art 130, an ambience signal

generator 131, and a channel selector 132. The parametric
stereo decoder takes a base channel (downmix) signal 133, a
panorama signal 134, and a stereo width signal 135
(corresponding to a parametric stereo bitstream according
to prior art methods, 136) as input, and generates a PSP
signal 137, which is fed to the channel selector. In
addition, the PSP is fed to the ambience generator, which
generates a DAP signal 138 in accordance with prior art
methods, e.g. by means of delays and reverberators, which
also is fed to the channel selector. The channel selector
takes a route signal 139, (which together the panorama
signal forms the direction parameter information 140) and
connects the PSP and DAP signals to the corresponding
output channels 141, in accordance with the table in Fig.
2. The straight lines within the channel selector
correspond to the case illustrated by Fig. la and Fig. 2,
route = 1. Optionally, the ambience generator takes an
ambience level signal as input, 142 to control the level
the ambience generator output. In an alternative embodiment
the ambience generator 131 would also utilize the signals
134 and 135 for the DAP generation.
Fig. lb illustrates another possibility of this scheme:
Here the non-adjacent 111 (L) and 114 (Rs) are selected as
the speaker pair. Hence, a virtual sound source can be
moved diagonally by means of the pan parameter, as
illustrated by the arrow 116. 115 outlines the localization
of the corresponding DAP signal. Route values 4 and 5 in
Fig. 2 correspond to this diagonal panning.
In a variation of the above embodiment, when selecting two
non-adjacent speakers, the speaker(s) between the selected
speaker-pair is fed according to a three-way panning
scheme, as illustrated by Fig. 3b. For reference Fig. 3a
shows a conventional stereo panning scheme, and Fig. 3b a
three-way panning scheme, both according to prior art
methods. Fig. lc gives an example of application of a
three-way panning scheme: E.g. if 102 (L) and 104 (R) form

the speaker pair, the signal is routed to 103 (C) for mid-
position pan values. This case is further illustrated by
the dashed lines in the channel selector 132 of Fig. 1d,
where the center channel output 143 of the generalized
parametric stereo decoder is active due to the 3 way
panning employed. In order to stabilize the sound stage,
pan-curves with large overlap may be used: The outer
speaker then contribute to the reproduction also at mid-
position panning, wherein the signal from the middle
speaker is attenuated correspondingly, such that a constant
power is achieved across the entire panning range. Further
examples of routing where three-way panning can be used are
C-R-Rs and L-[Ls & R]-Rs (i.e. mid-position panning yields
signals from both Ls and R). Whether the three-way-panning
should be applied or not can, of course, be signalled by
the route signal. Alternatively, a predefined behaviour
could be that the three-way-panning should be applied if
two non-adjacent speakers having at least one speaker in
between are indexed with the route signal.
The above scheme copes well with single sound sources, and
is useful for special sound effects, e.g. a helicopter
flying around. Multiple sources at different positions but
separated in frequency are also covered, if individual
routing and panning for different frequency bands is
employed.
A second embodiment of the present invention, hereinafter
referred to as 'angle & radius', is a generalization of the
above scheme wherein the following parameters are used for
positioning:
an angle parameter for continuously positioning a
sound across the entire speaker array (360 degree
range); and
a radius parameter for controlling the spread of sound
across the speaker array (0-1 range).

In other words, multiple speaker music material can be
represented by polar-coordinates, an angle a and a radius
r, where a can cover the full 360 degrees and hence the
sound can be mapped to any direction. The radius r enables
that sound can be mapped to several speakers and not only
to two adjacent speakers. It can be viewed as a
generalisation of the above three-way panning, where the
amount of overlap is determined by the radius parameter
(e.g. a large value of r corresponds to a small overlap).
To exemplify the embodiment above, a radius in the range of
[r] , which is defined from 0 to 1, is assumed. 0 means that
all speakers have the same amount of energy, and 1 could be
interpreted as that two channel panning should be applied
between the two adjacent speakers that are closest to the
direction defined by [α]. At the encoder, [α, r] can be
extracted using e.g. the input speaker configuration and
the energy in each speaker to calculate a sound centre
point in analogy to the centre of mass. Generally, the
sound centre point will be closer to a speaker emitting
more sound energy than a different speaker in a replay
setup. For calculating the sound centre point, one can use
the spatial positions of the speakers in a replay setup,
optionally a direction characteristic of the speakers, and
the sound energy emitted by each speaker, which directly
depends on the energy of the electrical signal for the
respective channel.
The sound centre point which is located within the multi
channel speaker setup is then parameterized with an angle
and a radius [α,r].
At the decoder side multiple speaker panning rules are
utilized for the currently used speaker configuration to
give all [α,r] combinations a defined amount of sound in
each speaker. Thus, the same sound source direction is

generated at the decoder side as was present at the encoder
side.
Another advantage with the current invention is that the
encoder and decoder channel configurations do not have to
be identical, since the parameterization can be mapped to
the speaker configuration currently available at the
decoder in order to still achieve the correct sound
localization.
Fig. 4a, where 401 through 405 correspond to 101 through
105 in Fig la, exemplifies a case where the sound 408 is
located close to the right front speaker (R) -404. Since r
407 is 1 and a 406 points between the right front speaker
(R) 404 and the right surround speaker (RS) 405. The
decoder will apply two channels panning between the right
front speaker (R) 404 and the right surround speaker (RS).
Fig. 4b, where 410 through 414 correspond to 101 through
105 in Fig la, exemplifies a case where the sound image 417
general direction is close to the left front speaker 411.
The extracted or 415 will point towards the middle of the
sound image and the extracted r 416 ensures that the
decoder can recreate the sound image width using multi
speaker panning to distribute the transmitted audio signal
belonging to the extracted a 415 and r 416.
The angle & radius parameterisation can be combined with
pre-defined rules where an ambience signal is generated and
added to the opposite direction (of α ) . Alternatively a
separate signalling of angle and radius for an ambience
signal can be employed.
In preferred embodiments, some additional signalling is
used to adapt the inventive scheme to certain scenarios.
The above two basic direction parameter schemes do not
cover all scenarios well. Often, a "full soundstage" is
needed across L-C-R, and in addition a directed sound is

desired from one back channel. There are several
possibilities to extend the functionality to cope with this
situation:
1. Send additional parameter-sets on an as-needed basis.
E.g. a system defaults to a 1:1 relation between the
downmix signal and the parameters, but occasionally a
second parameter-set is sent which also operates on
the downmix signal corresponding to a 1:2
configuration. Clearly, arbitrary additional sources
are obtainable in this fashion by means of
superimposing the decoded parameters.
2. Use decoder side rules (depending on routing and
panning or angle and radius values) to override the
default panning behaviour. One possible rule,
assuming separate parameters for individual frequency
bands, is "When only a few frequency bands are routed
and panned substantially different than the others,
interpolate panning of 'the others' for the 'few
bands' and apply the signalled panning for 'the few
ones' in addition to achieve the same effect as in
example 1. A flag could be used to switch this
behaviour on/off.
Stated in other words, this example uses separate
parameters for individual frequency bands, and is
employing interpolation in the frequency direction
according to the following: If only a few frequency
bands are routed and panned substantially different
(out-layers) than the others (main group), the
parameters of the out-layers are to be interpreted as
additional parameter sets according to the above
(although not transmitted). For said few frequency
bands, the parameters of the main group are
interpolated in the frequency direction. Finally the
two sets of parameters now available for the few
bands are superimposed. This allows placing an

additional source at a substantially different
direction than that of the main group, without
sending additional parameters, while avoiding a
spectral hole in the main direction for the few out-
layer bands. A flag could be used to switch this
behaviour on/off.
3. Signal some special preset mappings, e.g.
a) Route signal to all speakers;
b) Route signal to arbitrary single speaker; and
c) Route signal to selected subsets of speakers (>2).
The above three extended cases apply to the route & pan
scheme as well as to the angle & radius scheme. Preset
mappings are particularly useful for the route & pan case
as evident from the below example, where also ambience
signals are discussed.
Fig. 2 finally gives an example of possible special preset
mappings: The last two route values, 6 and 7, correspond to
special cases where no panning info is transmitted, and the
downmix signal is mapped according to the 4th column, and
ambience signals are generated and mapped according to the
last column. The case defined by the last row creates an
"in the middle of a diffuse sound field" impression. A
bitstream for a system according to this example could in
addition include a flag for enabling three-way panning
whenever speaker pairs in the PSP column are not adjacent
within the speaker array.
A further example of the present invention is a system
using one angle and radius parameter-set for the direct
sound, and a second angle and radius parameter-set for the
ambience sound. In this example a mono signal is
transmitted and used both for the angle and radius
parameter-set panning the direct sound and the creation of
a decorrelated ambience signal which is then applied using

the angle and radius parameter-set for the ambience.
Schematically a bitstream example could look like:



A further example of the present invention utilizes both
route & pan and angle & radius parameterisations and two
mono signals. In this example the angle & radius parameters
describe the panning of the direct sound from the mono
signal Ml. Furthermore route & pan is used to describe how
the ambience signal generated from M2 is applied. Hence the
transmitted route value describes, in which channels the
ambience signal should be applied and as an example the
ambience representation of Fig. 2 could be utilized. The
corresponding bitstream example could look like:




The parameterisation schemes for spatial positioning of
sounds in a multichannel speaker setup according to the
present invention are building blocks that can be applied
in a multitude of ways:
i) Frequency range:
Global (for all frequency bands) routing; or
Per-band routing.
ii) Number of parameter sets:
Static (fixed over time); or
Dynamic (additional sets sent on as-needed basis).
iii) Signal application, i.e. coding of:
Direct (dry) sound; or

Ambient (wet) sound.
iv) Relations between the number of downmix signals and
parameter sets, e.g.:
1:1 (mono downmix and single parameter set);
2:1 (stereo downmix and single parameter set); or
1:2 (mono downmix and two parameter sets) . The downmix
signal M is assumed to be the sum of all original
input channels. It can be an adaptively weighted and
adaptively phase adjusted sum(s) of all inputs.
v) Super position of downmix signals and parameter sets,
e.g.
1:1 + 1:1 (two different mono downmixes and
corresponding single parameter sets)
The latter is useful for adaptive downmix & coding, e.g.
array (beamforming) algorithms, signal separation (encoding
of primary max, secondary max,...) .
For the sake of clarity, in the following, panning using a
balance parameter between two channels (Fig. 3a) or between
three channels (Fig. 3b) according to prior art is
described. Generally, the balance parameter indicates the
localization of a sound source between two different
spatial positions of, for example two speakers in a replay
setup. Fig. 3a and Fig. 3b indicate such a situation
between the left and the right channel.
Fig. 3a illustrates an example of how a panorama parameter
relates to the energy distribution across the speaker pair.
The x-axis is the panorama parameter, spanning the interval
[-1,1], which corresponds to [extreme left, extreme right].
The y-axis spans [0,1] where 0 corresponds to 0 output and
1 to full relative output level. Curve 301 illustrates how
much output is distributed to the left channel dependant on
the panning parameter and 302 illustrates the corresponding
output for the right channel. Hence a parameter value of -1

yield that all input should be panned to the left speaker
and zero to the right speaker, consequently vice versa is
true for a panning value of 1.
Fig. 3b indicates a three-way panning situation, which
shows three possible curves 311, 312 and 313. Similarly as
in Fig. 3a the x-axis cover [-1,1] and the y-axis spans
[0,1]. As before curve 311 and 312 illustrates how much
signal is distributed to left and right channels. Curve 312
illustrates how much signal is distributed to the centre
channel.
Subsequently, the inventive concept will be discussed in
connection with Figs. 5a to 6b. Fig. 5a illustrates an
inventive apparatus for generating a . parametric
representation of an original multi-channel signal having
at least three original channels, the parametric
representation including a direction parameter information
to be used in addition to a base channel derived from the
at least three original channels for reconstructing an
output signal having at least two channels. Furthermore,
the original channels are associated with sound sources
positioned at different spatial positions in a replay setup
as has been discussed in connection with Figs, la, lb, lc,
4a, 4b. Each replay setup has a reference position 10 (Fig.
la), which is preferably a center of a circle, along which
the speakers 101 to 105 are positioned.
The inventive apparatus includes a direction information
calculator 50 for determining the direction parameter
information. In accordance with the present invention, the
direction parameter information indicate a direction from
the reference position 10 to a region in a replay setup, in
which a combined sound energy of the at least three
original channels is concentrated. This region is indicated
as a sector 12 in Fig. la, which is defined by lines
extending from the reference position 10 to the right
channel 104 and extending from the reference position 10 to

the right surround channel 105. It is assumed that, in the
present audio scene, there is, for example, a dominant
sound source positioned in the region 12. Additionally, it
is assumed that the local sound energy maximum between all
five channels or at least the right and the right surround
channels is at a position 14 . Additionally, a direction
from the reference position to the region and, in
particular, to the local energy maximum 14 is indicated by
a direction arrow 16. The direction arrow is defined by the
reference position 10 and the local energy maximum position
14.
In accordance with the first embodiment, which has, as the
direction parameter information, the route information
indicating a channel pair, and the balance or pan parameter
indicating an energy distribution between the two selected
channels, the reconstructed energy maximum can only be
shifted along the double-headed arrow 18. The degree or
position, where the local energy maximum in a multi-channel
reconstruction can be placed along the arrow 18 is
determined by the pan or balance parameter. When, for
example, the local sound maximum is at 14 in Fig. la, this
point can not exactly be encoded in this embodiment. For
encoding the local energy maximum direction, however, a
balance parameter indicating this direction would be a
parameter, which results in a reconstructed local energy
maximum lying on the crossing point between arrow 18 and
arrow 16, which is indicated as "balance (pan)" in Fig. la.
One possible embodiment of a route & pan scheme encoder is
to first calculate the local energy maximum, 14 in Fig. la,
and the corresponging angle and radius. Using the angle, a
channel pair (or triple) selected, which yields a route
parameter value. Finally the angle is converted to a pan
value for the selceted channel pair, and, optionally the
radius is used to calculate an ambience level parameter.

The Fig. la embodiment is advantageous, however, in that it
is not necessary to exactly calculate the local energy
maximum 14 for determining the channel pair and the
balance. Instead, necessary direction information is simply
derived from the channels by checking the energies in the
original channels and by selecting the two channels (or
channel triple e.g. L-C-R) having the highest energies.
This identified channel pair (triple) defines a sector 12
in the replay setup, in which the local energy maximum 14
will be positioned. Thus, the channel pair selection is
already a determination of a coarse direction. The "fine
tuning" of the direction will be performed by the balance
parameter. For a rough approximation, the present invention
determines the balance parameter simply by calculating the
quotient between the energies in the selected channels.
Thus, because of the other channels C, L, Ls, which have
not been selected, the direction 16 encoded by channel pair
selection and balance parameter may deviate a little bit
from the actual local energy maximum direction because of
the contributions of the other speakers. For the sake of
bit rate reduction, however, such deviations are accepted
in the Fig. la route and pan embodiment.
The Fig. 5a apparatus additionally includes a data output
generator 52 for generating the parametric representation
so that the parametric representation includes the
direction parameter information. It is to be noted that, in
a preferred embodiment, the direction parameter information
indicating a (at least) rough direction from the reference
position to the local energy maximum is the only inter-
channel level difference information transmitted from the
encoder to the decoder. In contrast to the prior art BCC
scheme, the present invention, therefore, only has to
transmit a single balance parameter rather than 4 or 5
balance parameters for a five channel system.
Preferably, the direction information calculator 50 is
operative to determine the direction information such that

the region, in which the combined energy is concentrated,
includes at least 50 % of the total sound energy in the
replay setup.
Furthermore or alternatively, it is preferred that the
direction information calculator 50 is operative to
determine the direction information such that the region
only includes positions in the replay setup having a local
energy value which is greater than 75 % of a maximum local
energy value, which is also positioned within the region.
Fig. 5b indicates an inventive decoder setup. In
particular, Fig. 5b shows an apparatus for reconstructing a
multi-channel signal using at least one base channel and a
parametric representation including direction parameter
information indicating a direction from a position in the
replay setup to the region in the replay setup, in which a
combined sound energy of at least three original channels
is concentrated, from which the at least one base channel
has been derived. In particular, the inventive device
includes an input interface 53 for receiving the at least
one base channel and the parametric representation, which
can come in a single data stream or which can come in
different data streams. The input interface outputs the
base channel and the direction parameter information into
an output channel generator 54.
The output channel generator is operative for generating a
number of output channels to be positioned in the replay
setup with respect to the reference position, the number of
output channels being higher than a number of base
channels. Inventively, the output channel generator is
operative to generate the output channels in response to
the direction parameter information so that a direction
from the reference point to a region, in which the combined
energy of the reconstructed output channels is
concentrated, is similar to the direction indicated by the
direction parameter information. To this end, the output

channel generator 54 needs information on the reference
position, which can be transmitted or, preferably,
predetermined. Additionally, the output channel generator
54 requires information on different spatial positions of
speakers in the replay setup which are to be connected to
the output channel generator at the reconstructed output
channels output 55. This information is also preferably
predetermined and can be signaled easily by certain
information bits indicating a normal five plus one setup or
a modified setup or a channel configuration having seven or
more or less channels.
The preferred embodiment of the inventive output channel
generator 54 in Fig. 5b is indicated in Fig. 5c. The
direction information is input into a channel selector. The
channel selector 56 selects the output channels, whose
energy is to be determined by the direction information. In
the Fig. 1 embodiment, the selected channels are the
channels of the channel pair, which are signaled more or
less explicitly in the direction information route bits
(first column of Fig. 2).
In the Fig. 4 embodiment, the channels to be selected by
the channel selector 56 are signaled implicitly and are not
necessarily related to the replay setup connected to the
reconstructor. Instead, the angle α is directed to a
certain direction in the replay setup. Irrespective of the
fact, whether the replay speaker setup is identical to the
original channel setup, the channel selector 56 can
determine the speakers defining the sector, in which the
angle a is positioned. This can be done by geometrical
calculations or preferably by a look-up table.
Additionally, the angle is also indicative of the energy
distribution between the channels, defining the sector. The
particular angle a further defines a panning or a balancing
of the channel. When Fig. 4a is considered, the angle α
crosses the circle at a point, which is indicated as,

"sound energy center", which is more close to the right
speaker 404 than to the right surround speaker 405. Thus, a
decoder calculates a balance parameter between speaker 404
and speaker 405 based on the sound energy center point and
the distances of this point to the right speaker 404 and
the right surround speaker 405. Then, the channel selector
56 signals its channel selection to the up-mixer. The
channel selector will select at least two channels from all
output channels and, in the Fig. 4b embodiment, even more
than two speakers. Nevertheless, the channel selector will
never select all speakers except a case, in which a special
all speaker information is signaled. Then, an up-mixer 57
performs an up-mix of the mono signal received via the base
channel line 58 based on a balance parameter explicitly
transmitted into the direction information or based on the
balance value derived from the transmitted angle. In a
preferred embodiment, also an inter-channel coherence
parameter is transmitted and used by the up-mixer 57 to
calculate the selected channels. The selected channels will
output the direct or "dry sound", which is responsible for
reconstructing the local sound maximum, wherein the
position of this local sound maximum is encoded by the
transmitted direction information.
Preferably, the other channels, i.e., the remaining or non-
selected channels are also provided with output signals.
The output signals for the other channels are generated
using an ambience, signal generator, which, for example,
includes a reverberator for generating a decorrelated "wet"
sound. Preferably, the decorrelated sound is also derived
from the base channel (s) and is input into the remaining
channels. Preferably, the inventive output channel
generator 54 in Fig. 5b also includes a level controller
60, which scales the up-mixed selected channels as well as
the remaining channels such that the overall energy in the
output channels is equal or in a certain relation to the
energy in the transmitted base channel (s). Naturally, the
level control can perform a global energy scaling for all

channels, but will not substantially alter the sound energy
concentration as encoded and transmitted by the direction
parameter information.
In a low-bit rate embodiment, the present invention does
not require any transmitted information for generating the
remaining ambience channels, as has been discussed above.
Instead, the signal for the ambience channels is derived
from the transmitted mono signal in accordance with a
predefined decorrelation rule and is forwarded to the
remaining channels. The level difference between the level
of the ambience channels and the level of the selected
channels is predefined in this low-bit rate embodiment.
For more advanced devices, which provide a better output
quality, but which also require an increased bit rate, an
ambience sound energy direction can also be calculated on
the encoder side and transmitted. Additionally, a second
down-mix channel can be generated, which is the "master
channel" for the ambience sound. Preferably, this ambience
master channel is generated on the encoder side by
separating ambience sound in the original multi-channel
signal from non-ambience sound.
Fig. 6a indicates a flow chart for the route and pan
embodiment. In a step 61, the channel pair with the highest
energies is selected. Then, a balance parameter between the
pair is calculated (62). Then, the channel pair and the
balance parameter are transmitted to a decoder as the
direction parameter information (36) . On the decoder-side,
the transmitted direction parameter information is used for
determining the channel pair and the balance between the
channels (64). Based on the channel pair and the balance
value, the signals for the direct channels are generated
using, for example, a normal mono/stereo-up-mixer (PSP)
(65). Additionally, decorrelated ambiences signals for
remaining channels are created using one or more
decorrelated ambience signals (DAP) (66).

The angle and radius embodiment is illustrated as a flow
diagram in Fig. 6b. In a step 71, a center of the sound
energy in a (virtual) replay setup is calculated. Based on
the center of a sound and a reference position, an angle
and a distance of a vector from the reference position to
the energy center are determined (72).
Then, the angle and distance are transmitted as the
direction parameter information (angle) and a spreading
measure (distance) as indicated in step 73. The spreading
measure indicates how many speakers are active for
generating the direct signal. Stated in other words, the
spreading measure indicates a place of a region, in which
the energy is concentrated, which is not positioned on a
connecting line between two speakers (such a position is
fully defined by a balance parameter between these
speakers) but which is not positioned on such a connecting
line. For reconstructing such a position, more than two
speakers are required.
In a preferred embodiment, the spreading parameter can also
be used as a kind of a coherence parameter to synthetically
increase the width of the sound compared to a case, in
which all direct speakers are emitting fully correlated
signals. In this case, the length of the vector can also be
used to control a reverberator or any other device
generating a de-correlated signal to be added to a signal
for a "direct" channel.
On the decoder-side, a sub-group of channels in the replay
setup is determined using the angle, the distance, the
reference position and the replay channel setup as
indicated at step 74 in Fig. 6b. In step 75, the signals
for the sub-group are generated using a one to n up-mix
controlled by the angle, the radius, and, therefore, by the
number of channels included in a sub-group. When the number
of channels in the sub-group is small and, for example,

equal to two, which is the case, when the radius has a
large value, a simple up-mix using a balance parameter
indicated by the angle of the vector can be used as in the
Fig. 6a embodiment. When, however, the radius decreases
and, therefore, the number of channels within the sub-group
increases, it is possible to use a look-up table on the
decoder-side which has, as an input, angle and radius, and
which has, as an output, an identification for each channel
in a sub-group associated with the certain vector and a
level parameter, which is, preferably, a percentage
parameter which is applied to the mono signal energy to
determine the signal energy in each of the output channels
within the selected sub-group. As stated in step 76 of Fig.
6b, decorrelated ambience signals are generated and
forwarded to the non-selected speakers.
Depending on certain implementation requirements of the
inventive methods, the inventive methods can be implemented
in hardware or in software. The implementation can be
performed using a digital storage medium, in particular a
disk or a CD having electronically readable control signals
stored thereon, which cooperate with a programmable
computer system such that the inventive methods are
performed. Generally, the present invention is, therefore,
a computer program product with a program code stored on a
machine readable carrier, the program code being operative
for performing the inventive methods when the computer
program product runs on a computer. In other words, the
inventive methods are, therefore, a computer program having
a program code for performing at least one of the inventive
methods when the computer program runs on a computer.

WE CLAIM
1. An apparatus for reconstructing a multi-channel signal using at least one
base channel and a parametric representation comprising direction
parameter information indicating a direction from a reference position in a
replay setup to a region in the replay setup, wherein a combined sound
energy of at least three original channels is concentrated, from which the
at least one base channel has been derived, and comprising a balance
parameter, the apparatus comprising:
an output channel generator for generating a number of output channels
to be positioned in the replay setup with respect to the reference position,
the number of output channels being higher than the number of base
channels,
wherein the output channel generator is configured to generate the
output channels in response to the direction parameter information so
that the direction from the reference position to the region, wherein the
combined energy of the reconstructed output channels is concentrated
depends on the direction indicated by the direction parameter information,
wherein the output channel generator is configured to select a pair of
output channels using the direction parameter to obtain a selected pair of
output channels, the direction parameter comprising information on a pair
of output channels as a direction from a reference position in a replay
setup to a region in the replay setup, wherein a combined sound energy
of at least three original channels is concentrated,

wherein the output channel generator is configured to calculate audio
signals for the selected pair of output channels using the balance
parameter indicating a balance between the selected pair of output
channels such that an energy distribution between the selected pair of
output channels is determined by the balance parameter, and
wherein the output channel generator is configured to calculate one or
more ambience channel signals for one or more channels not included in
the selected pair of output channels, wherein the output channel
generator comprises a hardware implementation.
2. The apparatus as claimed in claim 1, wherein the output channel
generator is operative to calculate at least two output channels based on
the direction parameter information and to use a signal derived from the
base channel, the signal being different from the base channel in terms of
delay, gain, correlation or equalization, for remaining output channels in
order to generate an ambience signal.
3. The apparatus as claimed in claim 2, wherein the output channel
generator is operative to calculate the remaining channels so that an
energy thereof is in accordance with a predefined setting or such that a
combined energy of the remaining channels depends on an ambience
parameter additionally included in the parametric representation.
4. The apparatus as claimed in claim 1, wherein the direction parameter
information include an angle related to the reference position in the replay

setup, the angle defining a vector originating from a reference position in
the replay setup, and wherein the output channel generator is operative
to map the angle to a sub-group of all channels in the replay setup and to
determine an energy distribution between the channels in the sub-group
based on the angle.
5. The apparatus as claimed in claim 4, wherein the direction parameter
information further includes an information on a length of a vector,
wherein the output channel generator is operative to map the angle such
that a number of channels in the sub-group depends on the length of the
vector.
6. The apparatus as claimed in claim 4, wherein the output channel
generator is operative to map the angle using a mapping rule which
depends on the replay setup to be connected to the apparatus for
reconstructing, and, wherein the mapping rule is such that energies of
two adjacent channels, which define a sector, wherein the vector is
located, are higher than energies of channels outside the sector.
7. The apparatus as claimed in claim 1, wherein the output channel
generator includes a decorrelator for generating a decorrelated signal
based on the at least one base channel, and
wherein the output channel generator is further operative to add the
decorrelated signal to direct sound output channels based on a coherence
parameter included in the parametric representation, or

to include the decorrelated signal into ambience output channels, which
have a distribution of energy, which is not controlled by the direction
parameter information.
8. The apparatus as claimed in claim 1, wherein the direction parameter
information comprises information on an identification of output channels
which are not adjacent to each other in the replay setup, and
wherein the output channel generator is operative to conduct an at least
three-channel panning for calculating an energy distribution between the
two channels identified by the direction parameter information and an at
least one channel between the identified channels based on the direction
parameter information.
9. A method of reconstructing a multi-channel signal using at least one base
channel and a parametric representation comprising direction parameter
information indicating a direction from a reference position in a replay
setup to a region in the replay setup, wherein a combined sound energy
of at least three original channels is concentrated, from which the at least
one base channel has been derived, and comprising a balance parameter,
the method comprising:
generating, by an output channel generator, a number of output channels
to be positioned in the replay setup with respect to the reference position,
the number of output channels being higher than the number of base
channels,

wherein the step of generating is performed such that the output channels
are generated in response to the direction parameter information so that
the direction from the reference position to the region, wherein the
combined energy of the reconstructed output channels is concentrated
depends on the direction indicated by the direction parameter information,
wherein the step of generating comprises
selecting a pair of output channels using the direction parameter to obtain
a selected pair of output channels, the direction parameter comprising
information on a pair of channels as a direction from a reference position
in a replay setup to a region in the replay setup, wherein a combined
sound energy of at least three original channels is concentrated,
calculating audio signals for the selected pair of output channels using the
balance parameter indicating a balance between the selected pair of
output channels such that an energy distribution between the selected
pair of output channels is determined by the balance parameter, and
calculating one or more ambience channel signals for one or more
channels not included in the selected pair of output channels, wherein the
output channel generator comprises a hardware implementation.



ABSTRACT


TITLE : "AN APPARATUS AND A METHOD FOR RECONSTRUCTING A
MULTI-CHANNEL SIGNAL USING AT LEAST ONE BASE CHANNEL AND
A PARAMETRIC REPRESENTATION"
The invention relates to an apparatus for reconstructing a multi-channel signal
using at least one base channel and a parametric representation comprising
direction parameter information indicating a direction from a reference position
in a replay setup to a region in the replay setup, wherein a combined sound
energy of at least three original channels is concentrated, from which the at least
one base channel has been derived, and comprising a balance parameter, the
apparatus comprising: an output channel generator for generating a number of
output channels to be positioned in the replay setup with respect to the
reference position, the number of output channels being higher than the number
of base channels, wherein the output channel generator is configured to
generate the output channels in response to the direction parameter information
so that the direction from the reference position to the region, wherein the
combined energy of the reconstructed output channels is concentrated depends
on the direction indicated by the direction parameter information, wherein the
output channel generator is configured to select a pair of output channels using
the direction parameter to obtain a selected pair of output channels, the
direction parameter comprising information on a pair of output channels as a
direction from a reference position in a replay setup to a region in the replay
setup, wherein a combined sound energy of at least three original channels is
concentrated, wherein the output channel generator is configured to calculate
audio signals for the selected pair of output channels using the balance
parameter indicating a balance between the selected pair of output channels
such that an energy distribution between the selected pair of output channels is

determined by the balance parameter, and wherein the output channel generator
is configured to calculate one or more ambience channel signals for one or more
channels not included in the selected pair of output channels, wherein the output
channel generator comprises a hardware implementation.

Documents:

03005-kolnp-2006 abstract.pdf

03005-kolnp-2006 claims.pdf

03005-kolnp-2006 correspondence others.pdf

03005-kolnp-2006 description(complete).pdf

03005-kolnp-2006 drawings.pdf

03005-kolnp-2006 form-1.pdf

03005-kolnp-2006 form-2.pdf

03005-kolnp-2006 form-3.pdf

03005-kolnp-2006 form-5.pdf

03005-kolnp-2006 international publication.pdf

03005-kolnp-2006 international search authority report.pdf

03005-kolnp-2006-correspondence others-1.1.pdf

03005-kolnp-2006-correspondence-1.2.pdf

03005-kolnp-2006-pct request.pdf

3005-KOLNP-2006-(28-03-2012)-CERTIFIED COPIES(OTHER COUNTRIES).pdf

3005-KOLNP-2006-(28-03-2012)-CORRESPONDENCE.pdf

3005-KOLNP-2006-(28-03-2012)-FORM-13-1.pdf

3005-KOLNP-2006-(28-03-2012)-FORM-13.pdf

3005-KOLNP-2006-(28-03-2012)-PA-CERTIFIED COPIES.pdf

3005-KOLNP-2006-(29-10-2012)-ABSTRACT.pdf

3005-KOLNP-2006-(29-10-2012)-CLAIMS.pdf

3005-KOLNP-2006-(29-10-2012)-CORRESPONDENCE.pdf

3005-KOLNP-2006-(29-10-2012)-DRAWINGS.pdf

3005-KOLNP-2006-(29-10-2012)-FORM-1.pdf

3005-KOLNP-2006-(29-10-2012)-FORM-2.pdf

3005-KOLNP-2006-(29-10-2012)-FORM-3.pdf

3005-KOLNP-2006-(29-10-2012)-FORM-5.pdf

3005-KOLNP-2006-ABSTRACT.pdf

3005-KOLNP-2006-AMANDED CLAIMS.pdf

3005-KOLNP-2006-AMANDED PAGES OF SPECIFICATION.pdf

3005-KOLNP-2006-CANCELLED PAGES.pdf

3005-KOLNP-2006-CORRESPONDENCE 1.1.pdf

3005-KOLNP-2006-CORRESPONDENCE.pdf

3005-KOLNP-2006-DESCRIPTION (COMPLETE).pdf

3005-KOLNP-2006-DRAWINGS.pdf

3005-KOLNP-2006-EXAMINATION REPORT.pdf

3005-KOLNP-2006-FORM 1.pdf

3005-KOLNP-2006-FORM 13.pdf

3005-kolnp-2006-form 18.pdf

3005-KOLNP-2006-FORM 2.pdf

3005-KOLNP-2006-FORM 3.pdf

3005-KOLNP-2006-FORM 5.pdf

3005-KOLNP-2006-GPA.pdf

3005-KOLNP-2006-GRANTED-ABSTRACT.pdf

3005-KOLNP-2006-GRANTED-CLAIMS.pdf

3005-KOLNP-2006-GRANTED-DESCRIPTION (COMPLETE).pdf

3005-KOLNP-2006-GRANTED-DRAWINGS.pdf

3005-KOLNP-2006-GRANTED-FORM 1.pdf

3005-KOLNP-2006-GRANTED-FORM 2.pdf

3005-KOLNP-2006-GRANTED-FORM 3.pdf

3005-KOLNP-2006-GRANTED-FORM 5.pdf

3005-KOLNP-2006-GRANTED-SPECIFICATION-COMPLETE.pdf

3005-KOLNP-2006-INTERNATIONAL PUBLICATION.pdf

3005-KOLNP-2006-INTERNATIONAL SEARCH REPORT & OTHERS.pdf

3005-KOLNP-2006-MISCLLENIOUS.pdf

3005-KOLNP-2006-OTHERS.pdf

3005-KOLNP-2006-PA.pdf

3005-KOLNP-2006-PETITION UNDER RULE 137-1.2.pdf

3005-KOLNP-2006-PETITION UNDER RULE 137.pdf

3005-KOLNP-2006-PETITON UNDER RULE 137-1.1.pdf

3005-KOLNP-2006-REPLY TO EXAMINATION REPORT.pdf

abstract-03005-kolnp-2006.jpg


Patent Number 257870
Indian Patent Application Number 3005/KOLNP/2006
PG Journal Number 46/2013
Publication Date 15-Nov-2013
Grant Date 13-Nov-2013
Date of Filing 18-Oct-2006
Name of Patentee DOLBY INTERNATIONAL AB
Applicant Address APOLLO BUILDING,3E HERIKERBERGWEG 1-35,1101 CN,AMSTERDAM ZUID-OOST,NETHERLANDS,NETHERLANDS
Inventors:
# Inventor's Name Inventor's Address
1 Fredrik Henn ARKITEKTVAEGEN 18, 2TR,S-168 32 BROMMA,SWEDEN
2 Jonas ROEDEN Oestervaegen 40 SE-169 55 Solna, SWEDEN
PCT International Classification Number G10L19/00; H04S3/00
PCT International Application Number PCT/EP2005/003950
PCT International Filing date 2005-04-14
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 0400997-3 2004-04-16 Sweden