TWI390993B - Method for encoding and decoding multi-channel audio signal and apparatus thereof - Google Patents

Description

Method and device for encoding and decoding multi-channel audio signals

The invention relates to an encoding method and a device thereof, a decoding method and a device thereof, and more particularly to an encoding method and a device thereof capable of encoding or decoding a multi-channel audio signal by using additional information of the compensated downmix signal. Decoding method and device thereof.

In a typical method of encoding a one-to-one multi-channel audio signal, a multi-channel audio signal is downmixed into a mono or stereo signal, and the mono or stereo signal is encoded with spatial information instead of Each channel of the multi-channel audio signal is encoded. In this method, the spatial information is used to reply to its original multi-channel audio signal.

The first figure is a block diagram of a typical system for encoding/decoding a pair of multi-channel audio signals. Referring to FIG. 1 , an audio signal encoder includes a downmix module and a spatial parameter estimation module, wherein the downmix module is configured to generate a downmix signal, and downmix a multi-channel audio signal into a calendar. The method of sound or mono signal is used, and the space estimation module is used to generate spatial information. The system can receive an artificial downmix signal that is processed externally rather than generating a downmix signal. An audio signal decoder interprets the spatial information generated by the spatial parameter estimation module, and returns the original multi-channel audio signal according to the interpretation result. However, during the period in which the audio signal encoder generates a downmix signal or an artificial downmix signal, the quasi-attenuation of the signal bits may occur during the process of adding different channel signals. Add points For example, if the two channels are not overlapped and there is an offset between them, then one of the two signal additions has a channel level DL12 lower than L1 and L2. with.

In a decoding process, the attenuation of the level of a downmix signal may cause distortion of the signal. For example, the relationship between the levels of the channels can be determined based on the channel level difference (CLD) information, wherein the channel level difference information is a spatial information indicating the difference between the channel levels. However, when the level of the downmix signal obtained by the channel addition is attenuated, the level of the decoded downmix signal will be lower than the level of the original downmix signal.

Due to the foregoing phenomenon, a multi-channel audio signal obtained by decoding may be boosted or suppressed at a predetermined frequency, thereby causing destruction of sound quality. In addition, since the degree of attenuation of a signal due to a partial deviation of the signal due to another signal varies with the frequency domain, a signal passes through an audio encoder and an audio decoder. The degree of distortion will also vary with frequency, and this problem cannot be completely solved by changing the energy of a downmix signal in a predetermined frequency domain.

The present invention provides an encoding method and apparatus for encoding a multi-channel audio signal using additional information that compensates for a downmix signal.

The present invention also provides a decoding method and apparatus for decoding a multi-channel audio signal using additional information that compensates for a downmix signal.

An aspect of the present invention is a decoding method, the decoding method comprising the steps of: extracting a downmix signal and additional information from an input signal; extracting spatial information and a compensation parameter from the additional information; according to the downmix signal and the The spatial information generates a multi-channel audio signal; and the multi-channel audio signal is compensated according to the compensation parameter.

Another aspect of the present invention is a decoding apparatus, comprising: a demultiplexer, a core decoder, a parametric encoder, and a multi-channel synthesizing unit, the demultiplexer extracting an encoded signal from an input signal a downmix signal and additional information; the core decoder generates a downmix signal by decoding the encoded downmix signal; the parameter encoder extracts spatial information and a compensation parameter from the additional information; the multichannel synthesis unit The method is configured to generate a multi-channel audio signal according to the downmix signal and the spatial information, and compensate the multi-channel audio signal by using the compensation parameter.

Another aspect of the present invention is an encoding method, the decoding method comprising the steps of: calculating spatial information according to a multi-channel audio signal and a down-mix signal; and calculating a compensation parameter according to the multi-channel audio signal and the down-mix signal And the compensation parameter is used to compensate the downmix signal.

A further aspect of the present invention is an encoding device comprising a spatial information computing unit, a compensation parameter calculating unit and a bit stream generating unit, wherein the spatial information calculating unit is configured to use a multi-channel audio signal and a The downmix signal calculates spatial information, and the compensation parameter calculation unit is configured to calculate a compensation parameter according to the multichannel audio signal and the downmix signal, and the compensation parameter compensates the downmix signal; the bit stream generation unit is used for borrowing The spatial information, the compensation parameter, and the downmix signal are combined with the result of the encoding to produce a bit stream.

Still another aspect of the present invention is a computer readable recording medium having a program for executing the above decoding method recorded thereon.

Still another aspect of the present invention is a computer readable recording medium having a program for executing the above encoding method recorded thereon.

In the encoding method, spatial information is calculated according to a multi-channel audio signal and a down-mix signal, and a compensation parameter for compensating the down-mix signal is calculated according to the multi-channel audio signal and the down-mix signal. Thereafter, a bit stream is generated by encoding the spatial information, the compensation parameter, and the downmix signal in combination with the result of the encoding. Therefore, the problem of quality destruction of the sound of a multi-channel audio signal can be avoided by compensating the multi-channel audio signal using a compensation parameter for compensating a down-mix signal.

The invention will be described in more detail below in conjunction with the drawings showing the preferred embodiments.

An embodiment of the encoding method, apparatus and decoding method thereof and apparatus therefor of the present invention can be applied to the processing of a multi-channel audio signal, but is not limited to such an application. In other words, the present invention can also be applied to the processing of other signals than multi-channel audio signals.

The second figure is a block diagram of an embodiment of an encoding apparatus of the present invention. Referring to the second figure, the encoding device includes a downmixing unit 110 and a compensation parameter. The computing unit 120, a spatial information computing unit 130, and a bit stream generating unit 170, wherein the bit stream generating unit 170 includes a core encoder 140, a parameter encoder 150, and a multiplexer 160.

The downmixing unit 110 generates a downmix signal by downmixing an input multichannel audio signal into a mono signal or a stereo signal. The compensation parameter calculation unit 120 combines the encapsulation or level of the downmix signal generated by the downmixing unit 110 or an input artificial downmix signal with a multi-channel audio used to generate the downmix signal or the input artificial downmix signal. The envelope or level of the signal is compared, and a compensation parameter required to compensate for the downmix signal is calculated based on the comparison result. The spatial information calculation unit 130 calculates spatial information of a multi-channel audio signal.

The core encoder 140 of the bit stream generation unit 170 encodes a downmix signal, and the parameter encoder 150 generates additional information by encoding the compensation parameter and the spatial information. Next, the multiplexer 160 generates a bit stream by combining the encoded downmix signal and the additional information. In more detail, the downmixing unit 110 generates a downmix signal by downmixing the input multichannel audio signal. For example, when downmixing a multi-channel audio signal having five channels (ie, channel 1 to channel 5) to a stereo signal, the downmix channel 1 can be combined with the channels 1 and 3 of the multi-channel audio signal. And the way of 4 is obtained, and the downmix channel 2 can be obtained by combining the channels 2, 3 and 5 of the multi-channel audio signal.

When a downmix signal is generated, the compensation parameter calculation unit 120 calculates a compensation parameter required to compensate the downmix signal, and the compensation parameter can be calculated by different methods. For example, suppose a multi-channel audio signal package Contains five different channels belonging to a predetermined frequency band, namely channels 1, 2, 3, 4 and 5, L1, L2, L3, L4 and L5 are the levels of channels 1, 2, 3, 4 and 5, respectively, downmixing Channel 1 includes channels 1, 3, and 4, and downmix channel 2 includes channels 2, 3, and 5. At this time, the level DL 134 of the downmix channel 1 and the level DL 235 of the downmix channel 2 can be represented by equation (1): [Mathematical Figure 1] DL134≦L1+g3*L3+g4*L4 DL235≦L3+g3*L3+g3*L3+g5*L5 where g3, g4 and g5 are the gains produced during a downmixing process. If a multi-channel audio signal is generated according to a downmix signal by decoding, the levels L1', L2', L3', L4', and L5' of the five channels of the generated multi-channel audio signal are ideally the same. The levels L1, L2, L3, L4, and L5 of the five channels of the original multi-channel audio signal. To achieve this goal, the compensation parameter CF123 of one of the downmix channel 1 and the compensation parameter CF235 of the downmix channel 2 can be calculated using equation (2): [Mathematical Figure 2] CF134=(L1+g3*L3+g4*L4)/ DL134 CF235=(L2+g3*L3+g5*L5)/DL235

In this embodiment, the compensation parameters of each downmix channel are calculated to reduce the amount of data to be transmitted, but the compensation parameters of each channel of a multi-channel audio signal can also be calculated. In other words, a compensation parameter can be calculated as the energy of a downmix signal and each channel of a multi-channel audio signal. The ratio of energy, or can be calculated as the ratio of the envelope of a downmix signal to the envelope of each channel of a multi-channel audio signal.

The spatial information calculation unit 130 calculates spatial information, wherein the spatial information may include channel level difference (CLD) information, inter-channel correlation (ICC) information, and channel prediction coefficient (CPC) information.

The core encoder 140 encodes a downmix signal, and the parameter encoder 150 generates additional information by encoding spatial information and a compensation parameter, wherein the compensation parameters can be encoded using the same method of encoding the channel level difference. For example, the compensation parameters may be encoded using a time or frequency difference encoding method, a classification pulse code modulation (PCM) encoding method, a pilot-based encoding method, or a Huffman codebook method. The multiplexer 160 generates a bit stream by combining the encoded downmix signal with additional information. In this manner, a bit stream containing compensation parameters as additional information and used to compensate for the level attenuation of the downmix signal can be generated.

When no level compensation is required, a flag for a compensation parameter can be set to a value of zero to reduce the bit rate of additional information. If there is no large difference between the values of the compensation parameters CF134 and CF235, only one of the two compensation parameters CF134 and CF235 can represent that the two compensation parameters CF134 and CF235 can be transmitted, and the two compensation parameters are not required for transmission. Both CF134 and CF235 are transmitted. In addition, if the value of a compensation parameter is not uniformly maintained over time, a predetermined flag can be used to indicate a previous compensation parameter value. used.

In this embodiment, a compensation parameter may be set according to a comparison result of the level of an input multi-channel audio signal and the level of a down-mix signal, but the compensation parameter may also be set or estimated by using a method different from the above method. It. In other words, since a compensation parameter can pattern the level of a downmix signal relative to the level attenuation of an input multichannel audio signal used to generate the downmix signal, a compensation parameter can be defined as a standard Ratio, wave format data, or a gain compensation value with linear/nonlinear characteristics. By using the mathematical model value as a compensation parameter value, the compensation parameter value is transmitted in an efficient manner, and a downmix signal can be compensated by using only a digital bit.

The third figure is a block diagram of an embodiment of a decoding apparatus of the present invention. Referring to the third figure, the decoding device includes a demultiplexer 310, a core decoder 320, a parameter decoder 330, and a multi-channel synthesizing unit 340.

The demultiplexer 310 demultiplexes additional information and a coded downmix signal from an input bit stream, and the core decoder 320 generates a downmix signal by decoding the encoded downmix signal. The decoder 330 generates spatial information and a compensation parameter according to the additional information obtained by the demultiplexer 310. The multichannel synthesizing unit 340 generates a spatial information and a compensation parameter obtained by the downmix signal obtained by the core decoder 320 and the parameter decoder 330. Multi-channel audio signal.

The fourth figure is a flow chart showing the operation of the decoding apparatus shown in the third figure of the present invention. Referring to the third and fourth figures, a bit stream of a multi-channel audio signal is received at step S400, and the demultiplexer 310 processes an encoded downmix signal and the received bit from the S405. Additional information from the stream is decoded. In step S410, the core decoder 320 generates a downmix signal by decoding the encoded downmix signal. In step S420, the parameter decoder 330 generates a compensation parameter and spatial information by decoding the additional information. In step S430, the multi-channel synthesizing unit 340 generates a multi-channel audio signal according to the spatial information and the downmix signal. In step S440, the multi-channel synthesis unit 340 compensates the multi-channel audio signal using the compensation parameter. More specifically, the multi-channel synthesis unit 340 can compensate the output of each of the plurality of channels obtained by decoding according to a downmix signal and spatial information, as defined by equation (3): [mathematics Figure 3] L1"=L1'*CF134 L2"=L2'*CF235 L3"=L3'*(CF124+CF235)/2 L4"=L4'*CF134 C5"=L5'*CF235 where L1', L2', L3', L4' and L5' are the energy levels of the channel, while CF124 And CF235 is the compensation parameter.

In this way, signal distortion at a predetermined frequency can be avoided by using a compensation parameter that is received simultaneously with spatial information in a decoding process, so that a multi-channel audio signal obtained by the decoding process can be moderately obtained. Compensation. In the present embodiment, the output of each channel can be compensated by a compensation parameter, but the present invention is not limited thereto. In other words, when the envelope of each channel is transmitted as a compensation parameter, the spatial information does not need to be transmitted because the spatial information can be generated based on the information about the envelope of each channel. Even if no spatial information is received, a decoding device may use two or more downmix channels to extract false spatial information from an input downmix signal, and may decode the input downmix signal according to the false spatial information.

Figure 5 is a block diagram of an embodiment of a decoding apparatus of the present invention. Referring to FIG. 5, the decoding device does not use spatial information as additional information, and generates a multi-channel audio signal based on only one downmix signal.

Referring to FIG. 5, the decoding apparatus includes a core decoder 510, a signal frame forming unit 520, a spatial information estimating unit 530, and a multi-channel synthesizing unit 540.

The core decoder 510 generates a downmix signal by decoding an input bit stream, and transmits the downmix signal to the signal frame forming unit 520, wherein the downmix signal can be an array obtained by using Prologic or Logic7. The shape downmix signal, but it is not limited to this in the present invention.

The signal frame forming unit 520 configures the data of the downmix signal obtained by the core decoder 510 such that the corresponding downmix signal can be synchronized in the form of a unit composed of a spatial audio coding (SAC) frame. In this signal frame forming process, if the quadrature mirror filter (QMF) and the mixed band signal are generated using an analysis filter band and the downmix signal obtained from the core decoder 510, the signal frame forming unit 520 can The mixed band signal is transmitted to the multi-channel synthesis unit 540 because the mixed band signal can be easily used in a decoding process.

The spatial information estimating unit 530 generates spatial information such as channel level difference information, inter-channel cross-correlation information, and channel prediction coefficient information according to a downmix signal obtained by the signal frame forming unit 520. In more detail, the spatial information estimating unit 530 generates spatial information required for each spatial audio encoded signal frame. At this time, the spatial information estimating unit 530 may collect the data of a downmix signal until the length of the collected combined data becomes the same as that of a signal frame, and then process the collected downmix signal data. Alternatively, the spatial information estimating unit may also generate spatial information required for each pulse code modulation (PCM) sample. The spatial information generated by the spatial information estimating unit 530 is not the data to be transmitted, so it is not required to be quantized or the like, and thus the spatial information generated by the spatial information estimating unit 530 can contain as much information as possible.

The multi-channel synthesis unit 540 is obtained according to the signal frame forming unit 520. The spatial information generated by the downmix signal and spatial information estimating unit 530 generates a multi-channel audio signal.

In this embodiment, the bit rate can be reduced compared to the conventional method of transmitting spatial signals for additional information. In addition, a multi-channel signal can also be generated using a method generally used to generate array downmix content.

Figure 6 is a block diagram of an embodiment of a decoding apparatus of the present invention. Referring to FIG. 6, when a bit stream including both a downmix audio signal and spatial information is received, the decoding device generates additional spatial information according to the spatial information included in the received bit stream. And using the additional spatial information to decode the downmixed audio signal.

Referring to the sixth figure, the decoding device includes a demultiplexer 610, a core decoder 620, a signal frame forming unit 630, a spatial information estimating unit 640, a multi-channel synthesizing unit 650, and a combining unit 660.

The demultiplexer 610 decodes the spatial information obtained from an input bit stream and the encoded downmix signal, and the core decoder 620 generates a downmix signal by decoding the encoded downmix signal, and the signal frame is formed. Unit 630 configures the data for the downmix signal obtained by core decoder 510 to synchronize the corresponding downmix signal in the form of a unit of spatial audio coded signal blocks. The spatial information estimating unit 640 generates additional spatial information according to the spatial information obtained by the demultiplexer 610 through estimation. The combining unit 660 combines the spatial information and spatial information obtained by the multiplexer 610. The additional spatial information generated by the estimation unit 640 is transmitted to the multi-channel synthesis unit 650. Then, the multi-channel synthesizing unit 650 generates a multi-channel audio signal according to the downmix signal generated by the core decoder 620 and the spatial information transmitted by the combining unit 660.

In this embodiment, the spatial information including the input bit stream and the additional spatial information obtained from the downmix signal through the estimation process can be used, and the spatial information included in an input bit stream is used. Various types of applications can be formed depending on the type, which will be described in more detail later.

When the spatial information including the length of time and the data band is received, that is, when the bit rate of the spatial information is so low that the data band of the spatial information is small or the transmission frequency of the spatial information is low, the spatial information estimating unit 640 According to the spatial information and a down-mix pulse code modulation signal, information without the spatial information is generated, thereby improving the quality of a multi-channel audio signal. For example, if spatial information including only five data bands is received, the spatial information estimating unit 640 can convert the spatial information into twenty-eight data bands by referring to the downmix signal received with the spatial information. Spatial information. If spatial information including only two time lengths is received, the spatial information estimating unit 640 may generate a downmix signal that is received in conjunction with the spatial information and generate a total of eight time lengths by interpolation.

Only part of the spatial information including channel level difference information, channel inter-correlation information and channel prediction coefficient information is received (eg only channel inter-channel The associated information is received. The spatial information estimating unit 640 can improve the quality of the multi-channel audio signal by estimating the channel level difference information and the channel prediction coefficient information. Similarly, when only the channel prediction coefficient information is received, the spatial information estimating unit 640 can generate inter-channel cross-correlation information through the estimation.

An encoding device downmixes an input multichannel signal into a downmix signal using a two-way (OTT) or two-to-three (TTT) box. When spatial information corresponding to only one of the pair of two or two pairs of three boxes is received, the spatial information estimating unit 640 may generate spatial information corresponding to the other pair of two and two pairs of three boxes by estimation, and according to the received The spatial information and the generated spatial information generate a multi-channel audio signal, and the spatial information estimate can be performed after spatially encoding and decoding the received spatial information. For example, if a downmix signal having two channels (ie, a left channel and a right channel) and spatial information corresponding to two pairs of three boxes are received, the spatial information estimating unit 640 may be configured according to the received downmix signal. The left and right channel signals produce L-channel, C (middle)-channel, and R-channel signals.

Thereafter, the spatial information estimating unit 640 can generate spatial information corresponding to a pair of two boxes. Then, the multi-channel synthesizing unit 650 generates a multi-channel audio signal according to the received spatial information and the spatial information generated by the spatial information estimating unit 640. The method can be applied when the number of output channels is large. For example, when a bit stream having a 525 format is input to one, it can provide more In the decoding device of the seven channels, the decoding device generates five channel signals (mixed domain) through spatial audio codec decoding processing, and generates spatial information required for expanding five channel signals to seven channels through estimation, and additionally performs Decoding processing to generate a signal that is more than one channel provided by a single bit stream.

The present invention can be implemented in the form of a computer readable code, and the computer readable code is written in a computer read recording medium, wherein the computer readable recording medium can be any type of data that can be stored in a computer readable manner. The recording device can be a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, and a carrier (such as data transmission through the Internet). In addition, the computer readable recording medium can be distributed among a plurality of computer systems connected to a network, and the computer readable code can be written to the computer systems and executed by the systems in a distributed manner. . The functional programs, codes, and code segments required to implement the present invention can be easily accomplished by those skilled in the art.

The present invention has been described and illustrated by the preferred embodiments thereof, and those skilled in the art will appreciate that the preferred embodiments can be variously modified without departing from the spirit and scope of the invention. Features will be defined in the scope of the following patent application.

[Industrial availability]

In the present invention, a decoded multi-channel audio signal can be used. A compensation parameter is compensated as additional information, wherein the compensation parameter is calculated by comparing the level of an input multi-channel audio signal with a down-mix signal. In addition, the present invention can generate additional spatial information according to the input spatial information and an input downmix signal, so that the decoded multi-channel audio signal can avoid distortion at a predetermined frequency, thereby improving the quality of the multi-channel audio signal. .

In the present invention, the destruction of sound quality is avoided by compensating a downmix signal using a compensation parameter during encoding and/or decoding of a multi-channel audio signal.

110‧‧‧downmixing unit

120‧‧‧Compensation parameter calculation unit

130‧‧‧Space Information Computing Unit

140‧‧‧core encoder

150‧‧‧Parameter encoder

160‧‧‧Multiplexer

170‧‧‧ bit stream generation unit

310‧‧‧Solution multiplexer

320‧‧‧core decoder

330‧‧‧Parameter decoder

340‧‧‧Multichannel synthesis unit

S400‧‧‧Steps

S405‧‧‧Steps

S410‧‧‧Steps

S420‧‧‧ steps

S430‧‧‧Steps

S440‧‧‧Steps

510‧‧‧ core decoder

520‧‧‧Signal frame forming unit

530‧‧‧Space Information Estimation Unit

540‧‧‧Multichannel synthesis unit

610‧‧‧Demultiplexer

620‧‧‧core decoder

630‧‧‧Signal frame forming unit

640‧‧‧ Spatial Information Estimation Unit

650‧‧‧Multichannel synthesis unit

660‧‧‧ combination unit

The above and other features and advantages of the present invention will become more apparent from the aspects of the embodiments of the invention. A block diagram of a typical system for decoding/encoding a multi-channel audio signal; a second diagram showing a block diagram of an embodiment of an encoding apparatus of the present invention; and a third diagram showing an embodiment of a decoding apparatus of the present invention Figure 4 is a block diagram showing the operation of the decoding apparatus shown in Figure 3 of the present invention; and Figure 5 is a block diagram showing another embodiment of the decoding apparatus of the present invention; And a sixth diagram showing another embodiment of a decoding apparatus of the present invention. Block diagram.

S400‧‧‧Steps

S405‧‧‧Steps

S410‧‧‧Steps

S420‧‧‧ steps

S430‧‧‧Steps

S440‧‧‧Steps

Claims (12)

A decoding method for a multi-channel audio signal, comprising: extracting a downmix signal and additional information from an input signal; extracting spatial information and a compensation parameter from the additional information; and based on the downmix signal and the spatial information Generating a multi-channel audio signal; and compensating the multi-channel audio signal according to the compensation parameter, wherein the encapsulation of the down-mix signal and the encapsulation of the multi-channel audio signal used to generate the down-mix signal are used to calculate The compensation parameter. The method of claim 1, wherein the compensation parameter comprises a ratio of the envelope of the downmix signal to the envelope of the multichannel audio signal used to generate the downmix signal. The method of claim 1, wherein the compensation parameter is applied to at least each channel of the multi-channel audio signal. The method of claim 1, further comprising: determining a compensation flag indicating whether the compensation parameter is included in the additional information. The method of claim 1, wherein the spatial information comprises at least one of channel level difference (CLD), inter-channel correlation (ICC), and channel prediction coefficient (CPC) information. A decoding apparatus for an audio signal, comprising: a demultiplexer that extracts an encoded downmix signal and additional information from an input signal; a core decoder that decodes the encoded downmix signal by Generating a downmix signal; a parameter decoder that extracts spatial information and a compensation parameter from the additional information; And a multi-channel synthesis unit that generates a multi-channel audio signal according to the downmix signal and the spatial information and compensates the multi-channel audio signal by using the compensation parameter, wherein the encapsulation of the down-mix signal is utilized and used to generate the multi-channel audio signal The compensation of the multi-channel audio signal of the downmix signal is calculated to calculate the compensation parameter. The decoding device of claim 6, wherein the multi-channel synthesis unit utilizes the compensation parameter, the envelope related to the downmix signal and the multi-channel audio signal used to generate the downmix signal The encapsulation ratio is to compensate for the multi-channel audio signal. The decoding apparatus according to claim 6, wherein the multi-channel synthesizing unit applies the compensation parameter to at least each channel of the multi-channel audio signal. The decoding device according to claim 6, wherein the parameter decoder extracts the compensation parameter from the additional information according to a compensation flag. An encoding method includes: calculating spatial information according to a multi-channel audio signal and a down-mix signal; and calculating a compensation parameter according to the encapsulation of the down-mix signal and the encapsulation of the multi-channel audio signal, the compensation parameter compensating Downmix signal. An encoding device includes: a spatial information computing unit that calculates spatial information according to a multi-channel audio signal and a downmix signal; a compensation parameter calculation unit that is based on the encapsulation of the multi-channel audio signal and the downmix signal Envelope to calculate a compensation parameter that compensates for the downmix signal; A one-bit stream generating unit that generates a bit stream by encoding the spatial information, the compensation parameter, and the downmix signal and combining the encoded result. A computer readable recording medium comprising a recorded program for providing the steps described in claim 1 of the scope of the patent application.