JP2005086389A - Acoustic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a delay process required for a surround extending process for extending N pieces of surround component data to M pieces of surround component data by a delay memory for M-1 channels. <P>SOLUTION: A surround extension circuit for newly generating M pieces of (M > N) surround component data from N pieces of delayed surround component data is provided, and a first and second delay circuits are arranged at the front and latter stages, respectively. The first delay circuit performs delay process for the least delay amount among each delay amount of the M pieces of surround component data, and the second delay circuit performs delays the remaining delay amount, thereby reducing operation quantity of the delay process, and the capacity of the delay memory required for the operation. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an audio apparatus that inputs multichannel audio data from various audio data sources and outputs the multichannel audio data to a multispeaker system in a stereoscopic audio system such as a home theater, for example. In addition, the present invention relates to an audio device having a function of converting and outputting data with an increased number of channels.

In recent years, for example, in home theater systems using a DVD player and a projector device, an audio device has been proposed in which various multichannel audio data are generated and supplied to a speaker system in order to obtain powerful sound effects. (For example, refer to Patent Document 1 and Patent Document 2).
In general, a speaker using a 5.1 speaker system of a left front speaker, a right front speaker, a center front speaker, a left surround speaker, a right surround speaker, and a bass speaker is provided. A 6.1 speaker system is provided by adding a central surround speaker to the .1 speaker system.
In the description of the present application, “surround” means “a sound that can be heard from the side or the back of the listener”.
For example, in a 6.1 speaker system, in order to obtain compatibility with audio data for 5.1 speaker system (5.1 channel audio data), 6.1 channel audio data is converted from 5.1 channel audio data. A surround expansion circuit is provided for creation. Various types of processing systems have been proposed for this surround expansion circuit (for example, Dolby Digital Surround EX provided by Dolby, see Non-Patent Document 1).

Further, in a multi-speaker system such as a 5.1 speaker system or a 6.1 speaker system, it is practically difficult to arrange each speaker for surround at an equal distance from a listener (user) as designed. Therefore, it is necessary to perform a delay process on the audio signal output to each speaker in accordance with the position of the speaker actually arranged. Therefore, when the user installs the speaker system, the position from his / her listening position (for example, the position of the sofa) to each speaker is registered in the system with the setting operation key, etc., so that the delay amount is calculated in the system. Is performed so as to delay the data output to each speaker.
Therefore, even in a system that performs surround expansion processing from 5.1 channels to 6.1 channels, surround data for three channels after the surround expansion processing (that is, left surround component data, right surround component data, and central surround) It is necessary to perform an optimum delay process on the component data) to correct an error in the distance between the listener and each speaker.
Japanese Patent Laid-Open No. 7-131900 JP 2003-188819 A Ongaku no Tomosha "Exploring Dolby and the Transition of Sound"

By the way, in a system that performs surround expansion processing as described above, when performing delay processing of surround data for three channels, usually, three surround delay circuits corresponding to each surround data are arranged at the subsequent stage of the surround expansion circuit, It can be considered that the three surround data are subjected to delay processing in parallel.
However, when the delay processing for three channels is performed in parallel in the subsequent stage of the surround expansion circuit in this way, the amount of arithmetic processing becomes enormous, and the capacity of the memory (delay memory) required at the time of calculation increases. There is a problem that causes an increase in cost.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an audio apparatus capable of realizing necessary delay processing with a delay memory for M-1 channels in a system for performing surround expansion processing for expanding N surround component data to M surround component data. It is to provide.

  In order to achieve the above-described object, an audio device according to the present invention specifies input means for inputting multichannel audio data and N surround component data of the multichannel audio data input by the input means, respectively. N first delay means for delaying by the amount and a surround for newly generating M (M> N) surround component data from the N delay surround component data delayed by the first delay means. Extending means, M second delay means for delaying the M surround component data generated by the surround extending means by a specified amount, the multi-channel audio data input by the input means, and the second The number of channels using M surround component data delayed by the delay means of An output unit that outputs the added multi-channel audio data to the speaker system, and a delay amount of the first delay unit and the second delay unit are determined based on distance information that is input according to an arrangement state of the speaker system. A delay amount dividing unit, wherein the first delay unit performs a delay process for the minimum value of the delay amounts of the M surround component data, and the second delay unit performs the remaining delay amount. Delay processing is performed.

According to the acoustic device of the present invention, the first delay unit is arranged in front of the surround expansion unit that newly generates M (M> N) surround component data from the N delay surround component data, Second delay means is arranged at the subsequent stage, the first delay means performs delay processing for the minimum value of each delay amount of the M surround component data, and the second delay means delays the remaining delay. By performing the processing, the amount of delay processing can be reduced, and the capacity of the delay memory required for the calculation can be reduced.
Accordingly, the processing time can be shortened by reducing the chip area by reducing the memory, reducing the power consumption, and simplifying the arithmetic processing, and allowance for other processing.

The acoustic apparatus of the present example is delayed by a first delay circuit that delays the left surround component Ls ′ and the right surround component Rs ′ of the 5.1 channel audio input by a specified amount, respectively, and the first delay circuit. A surround expansion circuit (an expansion method is arbitrary) for newly generating a left surround component Ls, a right surround component Rs, and a center surround component Bs from the left surround component Ls ′ and the right surround component Rs ′, and this surround expansion circuit And a second delay circuit that delays the left surround component Ls, the right surround component Rs, and the center surround component Bs generated by each by a specified amount, respectively, and a 5.1 channel audio input left front component L, right Front component R, center front component C, and bass component Sub and the left delay delayed by the second delay circuit The 6.1 component audio output is obtained by combining the sound component Ls, the right surround component Rs, and the center surround component Bs.
Further, the delay amount based on the speaker arrangement of the left surround component Ls, the right surround component Rs, and the center surround component Bs designated from the outside by an input operation of the user or the like is divided, and the first delay circuit and the second delay circuit are divided. There is provided a delay amount dividing circuit for calculating a delay amount designated for the delay circuit, and a delay memory in which the first delay circuit and the second delay circuit can be used in common.
The signal processing as described above is realized by a combination of hardware and software by a system configuration using, for example, a DSP (digital signal processor).

FIG. 1 is a block diagram showing a functional configuration of a main part that performs surround expansion processing of the audio apparatus according to the first embodiment of the present invention.
As shown in the figure, this audio apparatus mainly performs surround expansion processing by the DSP 100, and includes a serial / parallel conversion unit 110 provided in the input stage, and a signal reading unit 120 and D provided in the output stage. / A converter 130 is included.
The serial / parallel conversion unit 110 inputs a compressed audio data stream 111 reproduced from, for example, a DVD or other medium from an input terminal 112, converts the stream 111 into parallel data by serial / parallel conversion, and converts it into a memory of the DSP 100 (in FIG. 1). Store in (omitted).

The DSP 100 includes a decoding method determination unit 101, a decoding processing unit 102, a bass management unit 103, a surround expansion processing unit (including a delay processing unit) 104, a front channel delay processing unit 105, and the like as functions used in this example.
The decoding method determination unit 101 detects the code (compression) format of the compressed audio data stored in the memory by the serial / parallel conversion unit 110 and determines a decoding circuit to be used.
The decoding processing unit 102 performs a decoding (decompression) process on the compressed audio data according to the decoding method determined by the decoding method determining unit 101.
The bass management unit 103 performs bass management processing on the audio data decoded by the decoding processing unit 102. This is based on the bass component channel data in the audio data as reference data, and by combining this reference data with the filter data of the bass components of the other channel data L, R, C, Ls, Rs, a new bass component is obtained. The channel data Sub is generated. Various other methods are known for bass management. Such bass management is intended to compensate for, in particular, when the speaker capacity is insufficient to cope with the bass range, and is performed as necessary.

The surround expansion processing unit 104 performs surround expansion processing and delay processing for converting 5.1 channel data obtained through the bass management unit 103 into 6.1 channel data. The surround expansion processing in the surround expansion processing unit 104 can arbitrarily use various conventionally used methods, is not particularly limited, and is a delay processing that is a feature of the present invention. Will be described in detail later.
The front channel delay processing unit 105 performs a delay process for the front channel data of the 6.1 channel data obtained through the surround extension processing unit 104.

The signal reading unit 120 reads out the audio data on the memory processed by the DSP 100 as described above and outputs the audio data to the D / A conversion unit 130. The D / A conversion unit 130 converts the audio data into an analog signal. Then, the sound is output from the output terminal 131 to the speaker system to perform sound output.
Note that the memory (delay memory) used for the audio data processing in the DSP 100 described above may use the internal memory of the DSP 100 if the data amount is small in consideration of the relationship with the data amount, etc. For this, an externally connected memory may be used.

Next, delay processing in the surround expansion processing unit 104 described above will be described.
FIG. 2 is a block diagram illustrating a configuration example of the surround expansion processing unit 104 in this example.
As shown in the figure, the surround expansion processing unit 104 of this example is provided with delay circuits 211 and 212 for two channels in the preceding stage of the surround extension circuit 200 provided in the transmission path of the surround component data, and for three channels in the subsequent stage. Delay circuits 221, 222, and 223 are provided.
Further, a delay amount dividing circuit 230 for determining the delay amount of each delay circuit 211, 212, 221, 222, 223 is provided. It should be noted that the configuration and processing on the front component side are not particularly limited, and description thereof will be omitted assuming that processing is performed based on, for example, a method defined by Dolby.
In such a circuit, the surround component (Ls ′ / Rs ′) of the 5.1 channel audio input subjected to the bass management is delayed by the delay circuits 211 and 212 and expanded to three components by the surround expansion circuit 200. Thereafter, the signals are delayed again by the delay circuits 221, 222, and 223. As a result, the left surround component data Ls, the right surround component data Rs, and the center surround component data Bs are obtained, and the input left front component data L and front component data R are obtained. The center front component data C and the bass component data Sub are output as 6.1 channel audio data.

Next, the delay processing of this example will be described in detail. The delay circuits 211, 212, 221, 222, and 223 described above can be realized by the same quality circuits.
FIG. 3 is a block diagram showing the input / output relationship between the delay circuit and the delay memory of this example.
In this figure, any one of the delay circuits 211, 212, 221, 222, and 223 is indicated by a delay circuit 300, and a delay memory 310 shared by the respective delay circuits is shown. In the following description, the delay circuits 211, 212, 221, 222, and 223 are indicated by the number n, the delay circuit 211 is n = 0, the delay circuit 212 is n = 1, the delay circuit 221 is n = 2, and the delay circuit. 222 is represented by n = 3, and the delay circuit 223 is represented by n = 4.
In the figure, the input sample IN is accumulated in a queue (queue) realized by the delay memory 310. The output of the queue becomes the sample OUT. The size of the queue is Length [n] samples. As a result, the sample IN appears in the output sample OUT with a delay of Length [n] samples.
Here, Length [n] can be set from the outside as a delay amount command value. For example, to give a delay of 5 ms at 48 Hz, Length [n] = 48 × 5 = 240 is set.
Base [n] and Index [n] are variables for realizing the queue. Base [n] is a pointer variable pointing to an arbitrary location in the delay memory 300, and indicates the head of the queue. Index [n] is used together with Base [n] to indicate the location of the oldest data on the queue.

FIG. 4 is an explanatory diagram showing a setting example of the delay memory 310.
The relationship between Base [n] (n = 0-4) and Length [n] (n = 0-4) is set as shown in FIG. For example, Base [1] = Base [0] + Length [0]. Therefore, the consumption amount of the delay memory 310 can be obtained by the sum of Length [n] (n = 0 to 4).
FIG. 5 is a flowchart showing the operation of the delay circuit [n] (n = 0 to 4).
First, in step S1, it is determined whether Length [n] is 0, and based on the determination result, it is determined whether to perform a delay operation. If no delay is made, the input IN is directly copied to the output OUT in step S5.
When delaying, the oldest data on the queue of the delay memory 310 is copied to the output OUT in step S3. Next, in step S3, the input IN is copied to the same location as the location of the delay memory 310 referred to in step S2. Finally, in step S4, Index [n] is updated to reference the oldest data location on the queue.

FIG. 6 is a block diagram showing a configuration of the delay amount dividing circuit 230.
The delay amount dividing circuit 230 includes a minimum value selection circuit 231 and subtracters 232, 233, and 233, and each of the left, right, and center surround components according to the delay amounts Length_Ls, Length_Rs, and Length_Bs specified by the user. In order to delay the data, Length [n] (n = 0 to 4) is determined and sent to the delay circuit [n] (n = 0 to 4).
The minimum value selection circuit 231 selects the minimum value among the delay amounts Length_Ls, Length_Rs, and Length_Bs as Length_Com.
Since this minimum value Length_Com is considered as a delay common to the left, right, and center surround component data Ls, Rs, and Bs, the minimum value Length_Com can be passed to the preceding stage of the surround expansion circuit 200. Therefore, the minimum value Length_Com is passed to Length [0] and Length [1], and used as the delay amount of the delay circuits 211 and 212 (n = 0, 1) in the previous stage.

Next, the remaining amount of delay is
Length [2] = Length_Ls−Length_Com
Length [3] = Length_Rs−Length_Com
Length [4] = Length_Bs−Length_Com
The delays 221, 222, and 223 (n = 2, 3, 4) in the subsequent stage of the surround expansion circuit 200 are used to realize the corresponding delay.
Therefore, the sum of Length [n] (n = 0 to 4), which is the consumption amount of the delay memory 310, is
Length_Ls + Length_Rs + Length_Bs− Length_Com
It is obtained by. Here, the minimum value Length_Com is equal to one of the three designated delay amounts Length_Ls, Length_Rs, and Length_Bs.
Therefore, for example, when Length_Com = Length_Bs, the consumption amount is Length_Ls + Length_Rs, and it can be seen that the delay memory 310 has a capacity of two channels.

In the above embodiment, the present invention has been described by way of example of a surround expansion system that converts 5.1 channel audio data to 6.1 audio data. However, the present invention can be applied to other surround expansion systems as well. Is.
In the above example, the surround extension system that generates data for three channels from data for two channels has been described as an example. However, the present invention can be similarly applied to a surround extension system that handles a larger number of channel data. Is.

It is a block diagram which shows the function structure of the principal part which performs the surround expansion process of the audio equipment by Example 1 of this invention. It is a block diagram which shows the structural example of the surround expansion process part shown in FIG. FIG. 3 is a block diagram illustrating an input / output relationship between a delay circuit and a delay memory of the surround expansion processing unit illustrated in FIG. 2. FIG. 4 is an explanatory diagram illustrating a setting example of a delay memory illustrated in FIG. 3. 4 is a flowchart showing an operation of the delay circuit shown in FIG. 3. FIG. 3 is a block diagram illustrating a configuration of a delay amount dividing circuit of the surround expansion processing unit illustrated in FIG. 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... DSP, 101 ... Decoding method determination part, 102 ... Decoding processing part, 103 ... Bass management part, 104 ... Surround expansion processing part, 105 ... Front channel delay processing part, 110 ... Serial / Parallel conversion unit, 120... Signal readout unit, 130... D / A conversion unit.

Claims (5)

Input means for inputting multi-channel audio data;
N first delay means for delaying N surround component data of the multi-channel audio data input by the input means by a specified amount, respectively.
Surround expansion means for newly generating M (M> N) surround component data from the N delayed surround component data delayed by the first delay means;
M second delay means for delaying M surround component data generated by the surround extension means by a specified amount, respectively.
Output means for outputting multi-channel audio data having an increased number of channels to the speaker system using multi-channel audio data input by the input means and M surround component data delayed by the second delay means;
A delay amount dividing unit that determines a delay amount of the first delay unit and the second delay unit based on distance information input in accordance with an arrangement state of the speaker system;
The first delay means performs a delay process for the minimum value of the delay amounts of the M surround component data, and the second delay means performs a delay process for the remaining delay.
An acoustic device characterized by that.   The multichannel audio data input by the input means is 5.1 channel audio data including left front component data, right front component data, center front component data, left surround component data, right surround component data, and bass component data. 5. The multi-channel audio data with the increased number of channels is composed of left front component data, right front component data, center front component data, left surround component data, right surround component data, center surround component data, and bass component data. 2. The acoustic apparatus according to claim 1, wherein the audio apparatus is one-channel audio data.   The N delay surround component data are left surround component data and right surround component data, and the M delay surround component data are left surround component data, right surround component data, and center surround component data. The acoustic device according to claim 2.   2. The acoustic apparatus according to claim 1, wherein the first delay unit and the second delay unit perform data delay using a common delay memory. 2. The audio apparatus according to claim 1, wherein the multi-channel audio data delayed by the first delay means is bass-managed data using bass component data and bass components included in other component data. .

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