JP3716845B2 - Signal processing device connected to network - Google Patents

Description

  The present invention relates to a signal processing apparatus (node) connected to a network, for example, a music device that processes waveform signals. For example, the present invention relates to an expansion card format in which a music information communication function can be easily expanded.

A configuration configured to transmit and receive music data such as waveform data (audio waveform sample data) and performance data (performance event data such as MIDI) in a network configured in accordance with a predetermined communication standard (for example, IEEE 1394 standard) corresponding to multimedia. Music systems (for example, the music system of the present applicant called under the trademark “mLAN”). In such a music system, a plurality of nodes (for example, music equipment such as a synthesizer, a sound generator, a recorder, and a mixer) are connected via a network, and a large number of waveform data streams or MIDI data streams can be transmitted from an arbitrary node. Can be sent to multiple nodes. The following Patent Documents 1 and 2 are related to this.
Japanese Patent Laid-Open No. 10-032606 JP 2000-78170 A

  Japanese Patent Application Laid-Open No. H10-228561 discloses that in a music system as described above, a word clock is used to perform waveform data processing by synchronizing sample times among a plurality of nodes. One of the nodes becomes a word clock master, and transmits a word clock packet on the network every predetermined sample period. The frequency of the sampling clock of the word clock master is set to a common sampling frequency (for example, 48 kHz) of waveform data transmitted and received on the network. A node other than the word clock master (world clock slave) takes in a word clock packet on the network, regenerates a sampling clock having a sampling frequency synchronized with the word clock master based on this, and uses it for transmission / reception of waveform data. In this way, transmission / reception can be performed at a plurality of nodes on the network in synchronization with the sampling timing of the waveform data.

  Various types of music equipment such as synthesizers, sound generators, recorders, mixers, etc., originally execute the waveform signal processing functions (sound source waveform generation / synthesis function, mixing function, filter processing function, effect imparting function, etc.) In addition, a signal processing engine (software processing or hardware configuration signal processing means) is mounted, and in addition, in order to realize the communication function as described above, an expansion card for a communication function compliant with the IEEE 1394 standard or the like (Hereinafter referred to as a music LAN expansion card) can be mounted in the expansion slot of the music device 2. Here, the signal processing engine operates at a predetermined sampling frequency based on the system clock generated by the system clock generating means included in the music device. Here, among existing signal processing engines, a signal processing engine capable of following the sampling clock with a word clock supplied from outside, and a sampling frequency that cannot follow the word clock, that is, a fixed sampling frequency. And a signal processing engine that runs on The music LAN expansion card is an expansion card in which music equipment can be attached and detached, and includes a cycle timer similar to the cycle timer described in Patent Document 2. When the music apparatus is not a cycle master, the count value counted by the cycle timer is synchronized with the count value of the cycle master of the cycle master on the network. If the music device is a cycle master, the count value of the cycle timer of another device connected to the network is synchronized with the cycle timer of the music device. If the music device is a word clock slave, the sampling synchronized with the sampling frequency at the word clock master node based on the synchronized cycle timer and the word clock packet received from the word clock master node. Generate a frequency sampling clock. When the signal processing engine of the music device can follow the word clock, the music device can be operated as a word clock slave in synchronization with the sampling frequency of another node. However, when the signal processing engine of the music device has a fixed sampling frequency, the common sampling frequency of the music network is limited to the fixed sampling frequency rather than operating the music device as a word clock master. was there. Further, the conventional music LAN expansion card has a processor function for data transmission / reception operation control and a signal processing function such as a mixer function as a higher-level structure of the data transmission / reception operation function. Has become larger and more complex.

  The present invention has been made in view of the above points, and even when a music device having a signal processing engine having a fixed sampling frequency is connected to a network, a node other than the music device is connected to the word clock. The master is configured such that frequencies other than the fixed sampling frequency can be set as a common sampling frequency of the network.

  The present invention is a signal processing apparatus which is one of a plurality of devices connected to a network, wherein each device transmits a packetized waveform signal to another device via the network or from another device. A transmission / reception unit capable of receiving, wherein any one of the plurality of devices transmits a synchronization packet to another device as a master device, and the other device receives the synchronization packet as a slave device; In response to the sampling frequency of the waveform signal in the transceiver unit is synchronized with the sampling frequency of the master device, the signal processing device, the signal processing means for processing the waveform signal at a predetermined sampling frequency, Sampling for converting the sampling frequency of the waveform signal exchanged between the signal processing means and the transmission / reception unit of the apparatus When the wave number converting means and the apparatus are master devices, the waveform signal output from the signal processing apparatus is controlled to be transmitted from the transmitting / receiving unit without passing through the sampling frequency converting means, and the apparatus Is a slave device, the sampling frequency of the waveform signal output from the signal processing device is converted from the predetermined sampling frequency to the sampling frequency of the master device, and the waveform signal having the converted sampling frequency is converted into the waveform signal. A signal processing apparatus comprising: control means for controlling transmission from the transceiver unit.

  The present invention is also a signal processing apparatus which is one of a plurality of devices connected to a network, wherein each device transmits a packetized waveform signal to another device via the network or other device. A transmission / reception unit capable of receiving from a device, wherein any one of the plurality of devices transmits a synchronization packet to another device as a master device, and the other device receives the slave device as a slave device; The sampling frequency of the waveform signal in the transmission / reception unit is synchronized with the sampling frequency of the master device according to the synchronization packet, and the signal processing device includes a signal processing unit that processes the waveform signal at a predetermined sampling frequency; A sampler for converting the sampling frequency of the waveform signal exchanged between the signal processing means and the transmission / reception unit of the apparatus And the waveform signal received by the transmitter / receiver via the network are supplied to the signal processing means without going through the sampling frequency converting means. And when the device is a slave device, the sampling frequency of the waveform signal received by the transmission / reception unit via the network is changed from the sampling frequency synchronized with the sampling frequency of the master device to the predetermined sampling frequency. A signal processing apparatus comprising: a control unit that converts the waveform signal into a frequency and controls the waveform signal having the sampling frequency converted to be supplied to the signal processing unit.

  According to the present invention, when the slave operation is designated in the device, the signal (for example, audio waveform data) transmitted from the input / output unit to the network must follow the common sampling frequency. On the other hand, if the predetermined sampling frequency that defines the processing operation of the signal processing means does not match, it is conventionally impossible to operate (if it operates, noise is generated). However, according to the present invention, the sampling frequency of the waveform signal output from the signal processing device is converted from the predetermined sampling frequency to the sampling frequency of the master device by the sampling frequency conversion means, thereby converting the sampling frequency. Since the waveform signal thus transmitted is transmitted from the transmission / reception unit, the operation is not disabled. Therefore, even if the processing operation of the signal processing means of the signal processing device (node) is fixed to the predetermined sampling frequency, the frequency that can be used as a common sampling frequency in the network is included in the network. It is not limited by the signal processing device (node), and diversity can be provided.

  According to the present invention, when processing a signal received via a network, the sampling frequency of the waveform signal received via the network by the transmission / reception unit is also synchronized with the sampling frequency of the master device. The converted sampling frequency is converted into the predetermined sampling frequency, and the waveform signal with the converted sampling frequency is supplied to the signal processing means, so that the processing operation of the signal processing means of the signal processing device (node) Is fixed at the predetermined sampling frequency, the frequency that can be used as a common sampling frequency in the network is not limited by the signal processing device (node) included in the network, and has diversity. be able to.

  As an example, the designation unit receives designation information of a master operation or a slave operation given from the outside, and the input / output unit, the sampling frequency conversion unit, and the designation unit are mounted on an expansion card, The extension card is attached to the signal processing device having the signal processing means, and the designation information is supplied from another control device existing on the network. As a result, the designation means may be configured only to receive (for example, only store) designation information given from the outside, and a processor for managing the master / slave function of each node on the network is not required. Can be greatly simplified.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a block diagram conceptually showing a basic configuration example of a music system according to the present invention. This music system is composed of a plurality of nodes connected via a network that complies with a predetermined communication standard, for example, the IEEE 1394 standard (which may be the USB standard or others). In the figure, as a basic example of a node, a control device (for example, a personal computer) 1 and a music device 2 are illustrated, and other nodes (devices) are appropriately connected. Each node is connected via a bus 3, and between each node, music data can be packet-transferred by a plurality of channels in accordance with a predetermined communication standard. Between each node on the network, waveform data (audio waveform sample is transmitted). Data) and music data such as performance data including performance event data such as MIDI can be transmitted and received. The network connection method is not limited to the chain connection method in which the nodes are sequentially connected in a chain as shown in the figure, but may be a method in which each node is connected via a hub device, and is not limited to a wired connection. A method of connecting to a wireless method may be used.

  The control device 1 is typically composed of a personal computer. The personal computer 1 is provided with a music LAN interface unit 13 in accordance with a communication standard such as the IEEE 1394 standard and the mLAN standard which is a higher music data communication standard proposed by the present applicant. The music LAN interface unit 13 uses the IEEE 1394 standard interface (I / F) 11 as a lower layer and the IEEE 1394 standard I / F 11 as an upper layer, and a music LAN driver 12 for controlling communication of music data according to the mLAN standard. The IEEE 1394 standard I / F 11 and the music LAN driver 12 are each a communication control unit for remotely controlling a music LAN interface 21 (lower layer) of the music device 2 to be described later via a network. (Upper layer). The IEEE 1394 standard I / F 11 is an interface configured by hardware and software that performs data communication in accordance with the IEEE 1394 standard, and performs actual data transmission / reception operations (that is, data transmission to the bus 3 and the bus 3) via the network. Data input from the bus 3). As is well known, in the IEEE 1394 standard, data packets are communicated by isochronous transfer and asynchronous transfer every transfer cycle of a predetermined period (for example, 125 μs). Data that requires strict real-time characteristics such as music data is transferred by isochronous transfer, and transmission / reception node connection setting information such as a patch bay and other data that does not require strict real-time characteristics are transferred by asynchronous transfer. In this example, music data is cited as data that is isochronously transferred via an IEEE 1394 standard interface, but other data such as video data is also isochronously transferred. Note that the music LAN driver 12 in the upper layer is a software driver that performs a music data transmission / reception operation in accordance with the IEEE 1394 standard I / F 11, and therefore other data such as video data is not controlled by the music LAN driver 12.

  In FIG. 1, a layer structure of a protocol implemented in the personal computer 1 is drawn in a block indicating the personal computer 1. In other words, the IEEE 1394 layer is located below the music LAN, and performs basic initial settings and bus management control in the network, and isochronous transfer of data packets to and from other nodes according to control from higher layers. Or asynchronous transfer. In the layer of the music LAN interface unit 13, input / output plugs for waveform data and MIDI data for isochronous transfer are defined, and sampling frequency synchronization based on word clock packets is performed in accordance with control from various application programs 10 thereabove. And isochronous transfer of waveform data and MIDI data between input / output plugs of a plurality of nodes. One of such application programs includes a program (patch bay program) for setting connection between input / output plugs provided in a plurality of nodes and setting which node is a word clock master.

The music device 2 includes any music-related device such as an electronic musical instrument such as a music synthesizer, an automatic performance device such as a sequencer, a waveform recording device such as a recorder, a signal processing device such as a mixer or an effector, and a sound source device. Equivalent to. In this embodiment, the music device 2 is an electronic musical instrument such as a music synthesizer as an example.
The music device 2 includes a control unit 23 that performs overall operation control. The control unit 23 has a music LAN expansion card 20, a signal processing engine 30, a keyboard 24 for performance operation, and various setting operations. The child device 25, the display 26, etc. are connected. The signal processing engine 30 performs signal processing of waveform data at a fixed sampling frequency, and performs waveform data generation processing (sound source processing) in the synthesizer. The signal processing performed by the signal processing engine 30 may be configured to perform various processes such as mixer processing, filter processing, effect processing, audio waveform reproduction processing, and the like according to the purpose / function of the music device 2. As an example, the signal processing engine 30 may be configured by a DSP (digital signal processor), and its waveform processing function may be appropriately set by a DSP microprogram.

The music LAN expansion card 20 is an interface card according to communication standards such as the IEEE 1394 standard and the mLAN standard proposed by the present applicant, and is roughly divided into a music LAN interface (music LAN I / O) 21 and a sampling frequency converter ( Fs converter) 22. The music LAN interface unit 21 executes communication excluding a communication control unit (upper layer) for exchanging commands and status with other nodes of hardware or software conforming to the IEEE 1394 standard and its higher mLAN standard. Only hardware (lower layer) is provided. This communication execution unit is connected to the bus 3, and in accordance with control from the communication control unit in the music LAN I / F 11 of the control device 1, isochronous waveform data and MIDI data between the music device and other nodes. Perform the transfer. Here, the communication control unit of the control device 1 acts as a proxy for the communication control unit (upper layer) that the music device 2 should originally have in accordance with the IEEE 1394 standard and the mLAN standard. That is, the communication control unit of the control device 1 receives a command from its own node or another node instead of the communication control unit of the music device 2, and returns a status or performs remote control of the communication execution unit of the music device 2. . Alternatively, a command is transmitted to the own node or another node instead of the communication control unit of the music device 2, or a status as a response to the command is received. This proxy mechanism is described in detail in a previous application by the present applicant, Japanese Patent Application Laid-Open No. 2003-37609.
As will be described later, the sampling frequency converter 22 is provided to appropriately convert the sampling frequency of waveform data exchanged between the music LAN interface 21 and the signal processing engine 30. Note that a part or all of the music LAN interface unit 21 compliant with the mLAN standard and the sampling frequency converter 22 of the present embodiment can be implemented by software.

  The music device 2 further includes a MIDI input / output interface (MIDII / O) 27 for inputting / outputting MIDI performance data and a waveform input / output interface (waveform I / O) for inputting / outputting analog or digital waveform data. O) 28 is provided. The waveform input / output interface 28 converts an analog waveform input from the outside into waveform data having the fixed sampling frequency and inputs the waveform data to the signal processing engine 30, and is output from the signal processing engine 30. And a digital / analog converter for converting the waveform data of the fixed sampling frequency into an analog waveform and outputting the analog waveform to the outside. The waveform interface 28 is connected to a pickup microphone (not shown), a sound system for audio sound generation, and other waveform data input / output devices. The MIDI interface 27 inputs or outputs MIDI performance data to the control unit 23 in real time or non-real time, and is connected to a MIDI input / output device such as a MIDI musical instrument or a sequencer (not shown).

The music LAN interface 21 provided on the expansion card 20 communicates mLAN standard-compliant music data (waveform data and MIDI performance data) via a network, and has a data transmission / reception function of the IEEE 1394 standard in a lower structure. . The music LAN interface 21 includes a buffer memory such as a FIFO for buffering music data transmitted / received on the network (bus 3), the cycle timer synchronized between nodes on the network, and the cycle timer. A word clock means for realizing a common sampling frequency on the network based on the output is included.
As shown in Patent Document 2, in order to synchronize the sampling timing of each node connected on the network, any one of a plurality of nodes becomes a word clock master, and the sampling period unique to the node A word clock packet is generated on the basis of the word clock generated in step 1 and the count value of the cycle timer of the relevant node and transmitted to another node. The other node (word clock slave) that receives the word clock packet is synchronized with the word clock generated by the word clock master based on the received word clock and the count value of the cycle timer of the node. Is generated.

  The expansion card 20 has storage means for storing a master / slave flag indicating whether or not the own music device 2 is a word clock master node. In this embodiment, each node other than the music device 2 receives master / slave designation information given from the personal computer 1 via the bus 3, sets one of the nodes as a word clock master, Set the node as a word clock slave. For the music device 2, instead of the music device 2 receiving the master / slave designation information directly, the communication control unit on the personal computer 1 receives the communication device, and the communication control unit receives the master / slave designation information according to the received master / slave designation information. The communication execution unit is remotely controlled via the bus 3. As a result, it is not necessary to mount an upper layer conforming to the IEEE 1394 standard or the mLAN standard on the music device 2 side, so that the configuration of the expansion card 20 or the music device 2 can be simplified.

  The connection setting between one or a plurality of input / output plugs provided in each of the plurality of nodes in the music system and the word clock master / slave designation for each node are realized by executing the patch bay program on the personal computer 1. The With this patch bay program, the input / output plugs of a plurality of nodes connected on the network can be arbitrarily logically connected. A plurality of waveform data input plugs (waveform input plugs) at one or more nodes can be logically connected to one waveform data output plug (waveform output plug) at a certain node. Such a connection status in the network is displayed on the screen of the personal computer 1. An example of this screen display is shown in FIG. All waveform output plugs of all nodes connected to the network are listed in the audio output column. In addition, the waveform input plugs connected to the waveform output plugs of other nodes among all the waveform input plugs of all the nodes are displayed in a list in the connection destination column in association with the waveform output plugs, Waveform input plugs that are not connected to any waveform output plug are listed in the audio input column. In the example shown in the figure, an “Audio page list menu screen” that displays a list of connection statuses related to waveform data is shown. The connection status of other data (such as MIDI data) may be displayed in a list on another page, for example.

The setting of the word clock master / word clock slave will be described.
While viewing this “Audio page list menu screen”, the user selects one of all the waveform output plugs of all the nodes displayed in the audio output column with the cursor, and designates that node as the word clock master. By performing this operation, a node other than the node on the network can be set as a word clock slave, and the node can be set as a word clock master. In the screen display example of FIG. 2, in the “audio output” column, the word clock setting state (the column indicated by “WCLK” in FIG. 2) is on the left side of the device “model name: YYYYY” set as the data transmission device. It is shown. As shown in the figure, the character string “M1” is displayed, which indicates that the device is a group 1 word clock master. On the other hand, in the “connection destination” column, the word shown on the left side of the device “model name: ZZZ” that is logically connected to the data transmitting device “model name: YYYYY” and set as the data receiving device that receives the transmitted data. In the clock setting state (“WCLK” column), the character string “S1” is displayed, which indicates that the device is a group 1 word clock slave. As an example of setting the word clock master, for example, the user selects one of the waveform output plugs of the desired device from all the waveform output plugs of all the devices existing on the network displayed in the audio output column. Then, when an operation for setting this as a word clock master of a certain group (such as selecting an item of “Group 1 Master” from the menu that appears by right-clicking the mouse by left-clicking the mouse) is performed from the personal computer 1 Master / slave designation information is transmitted to a node belonging to the group, and nodes other than the selected device of the group are set as the word clock slave of the group, and the device is set as the word clock master of the group. The As another setting example of the word clock master, a list of devices that can be set as the word clock master is displayed for a certain device set as the word clock slave, and the user can specify a desired device from the list. You may do it. Such word clock master / slave settings can be set and changed intuitively with reference to the display, and the operability is excellent.
Here, if the device that can be set as the word clock master is a device that exists on the network, the device that is set as the data transmitting device, the device that is set as the data receiving device, or a device that is not related to data transmission / reception Any of three-party equipment can be used. Although the case where the word clock synchronization is performed in units of groups has been described, any one on the network may be set as the word clock master, and the word clock synchronization may be performed at all nodes on the network.

  Clicking with the mouse any one of the output plugs of the waveform output plugs displayed in the audio output column of FIG. 2 and any one of the waveform input plugs displayed in the audio input column, etc. 2 and operating the “Connect” button in FIG. 2 with a mouse or the like to connect the selected waveform output plug to the waveform input plug, and display the connected waveform input plug in the audio input field. Is displayed at the corresponding position on the right side of the display of the connected waveform output plug in the connection destination column. Further, by selecting an arbitrary one of the waveform input plugs displayed in the connection destination column and operating the “Cut” button in FIG. 2, the connection of the waveform input plug is cut and the connection is cut. The displayed waveform input plug is deleted from the connection destination column and displayed in the audio input column. In this way, the connection from any waveform output plug on the network to any waveform input plug can be added and deleted.

The isochronous transfer of waveform data (and MIDI data) according to the above connection will be briefly described. In the IEEE 1394 standard, a plurality of devices can perform data transmission by isochronous transfer by assigning a plurality of isochronous channels to a plurality of devices.
Each device outputs MIDI data or waveform data to be output from an input plug connected to an input plug of any other device among the plurality of MIDI data and waveform data output plugs of the device. Output on the network using the isochronous channel assigned to the device. On the other hand, a device having an input plug for MIDI data or waveform data connected to an output plug of any device detects an isochronous channel assigned to the connected device, and is transferred by the isochronous channel. The extracted data is taken out, and the MIDI data or waveform data from the output plug connected to the input plug is taken out from the fetched data and used as input data from the input plug. Here, according to the mLAN standard, since the word clock can be synchronized at a plurality of nodes on the network, waveform data transferred by isochronous transfer from a certain node can be received without disturbance of jitter or the like at the node receiving it. It can be taken out accurately. In other words, accurate synchronization is performed between the sampling frequency of the waveform data transmitted by isochronous transfer and the sampling frequency of the waveform data received and extracted. Therefore, when connecting the output plug of one device to the input plug of another device, the two devices must have their word clocks synchronized with each other.

FIGS. 3A to 3D are block diagrams for explaining an example of sampling frequency conversion operation when the node (music device 2) is operating as a word clock master node or a word clock slave node.
FIG. 3A shows an operation example when the music device 2 itself is a word clock master. The signal processing engine 30 performs a waveform processing operation according to a predetermined operation clock (for example, the system clock SCLK), and a frequency that is a fraction of the frequency is a sampling frequency fs (for example, 44) at which the signal processing engine 30 handles the waveform data. 0.1 kHz, etc.). In the music device 2 as the word clock master, the signal processing engine 30 of the own device supplies the sampling clock synchronized with the waveform data together with the waveform data subjected to the waveform processing to the music interface 21 as the word clock WCLK. The music LAN interface 21 obtains samples for a plurality of sampling periods of the waveform data supplied from the signal processing engine for each isochronous cycle designated by the cycle master node on the network, and counts the cycle timer for each predetermined number of samples. Is given a time stamp based on the packet and packetized, and transmitted to the network through the isochronous channel assigned to the node.

In FIG. 3A, when the music device 20 as a word clock master node functions as a data transmission device, the nodes other than the music device 2 capture the packet as a word clock packet, and based on the word clock packet. The word clock of the node in synchronization with the word clock of the music device 1 (sampling clock having a common sampling frequency S) is generated. In isochronous transfer of waveform data in the network, the sampling clock of the signal processing engine 30 of the music device 2 or a word clock synchronized therewith is used as the sampling clock of the waveform data to be transferred. Therefore, in this case, the waveform data output from the signal processing engine 30 can be supplied to the music LAN interface 21 without going through the sampling frequency converter 22, and the waveform data supplied to the music LAN interface 21 is It is packetized as it is and sent over the network.
3A, the same applies to the case where the music device 20 functions as a data receiving device. Since the sampling clock of the signal processing engine 30 is a clock of waveform data that is isochronously transferred, the LAN interface 21 The waveform data received from another device via the network is synchronized with the sampling clock of the signal processing engine 30 and is supplied to the signal processing engine 30 as it is without passing through the sampling frequency converter 22.
In addition, although the case where it is a data transmission apparatus and the case where it is a data reception apparatus was demonstrated separately, the music apparatus 2 can perform transmission and reception of the waveform data by isochronous transfer simultaneously in parallel.

FIG. 3B shows an operation example when the music device 2 is a word clock slave. In the music LAN interface 21 as a word clock slave node, the word clock packet sent from the word clock master node on the network is fetched, and the word clock synchronized with the word clock of the word clock master node based on the received word clock packet. (Sampling clock) is generated. This word clock becomes a sampling clock for waveform data transmitted or received by the music LAN interface 21 by isochronous transfer.
When the music device 2 functions as a word clock slave, the sampling frequency converter 22 converts the sampling frequency of the waveform data exchanged between the signal processing engine 30 and the music LAN interface 21. The sampling frequency converter includes a sampling clock from the signal processing engine 30 (a sampling clock for waveform data processed by the signal processing engine 30) and a sampling clock from the music LAN interface (waveform data transmitted and received by isochronous transfer). Sampling clock).

  In FIG. 3B, when the music device 2 as a slave node functions as a data transmission device, the sampling frequency converter 22 receives a sample of waveform data supplied from the signal processing engine 30 together with the word clock from the music LAN interface. Converts to waveform data synchronized with the supplied word clock. That is, the waveform data supplied from the signal processing engine 30 is converted from the signal processing sampling frequency in the signal processing engine 30 to the isochronous transfer sampling frequency (common sampling frequency S) in the music LAN interface 21. The waveform data converted to the common sampling frequency S is supplied to the music LAN interface 21, and the music LAN interface 21 samples samples for a plurality of sampling periods of the waveform data of the common sampling frequency S for each isochronous cycle. Each predetermined number is given a time stamp based on the count value of the cycle timer, packetized, and transmitted to the network through the isochronous channel assigned to the music device 2. In this way, the word clock slave node matches the sampling frequency fs of the waveform data output from the signal processing engine 30 to the common sampling frequency S on the network.

In FIG. 3B, when the music device 2 as a slave node functions as a data receiving device, the waveform data received from the network follows the common sampling frequency S. Therefore, the waveform data received by the music LAN interface 21 Is supplied to the sampling frequency converter 22 to perform sampling frequency conversion. The sampling frequency converter 22 converts the sampling frequency of the input received waveform data from the common sampling frequency S for isochronous transfer to a fixed sampling frequency fs for signal processing in the signal processing engine 30, and the sampling frequency fs. The waveform data converted into is output to the signal processing engine 30.
Thus, since the sampling frequency of the waveform data can be arbitrarily converted between the signal processing engine 30 and the music LAN interface 21, the frequency that can be used as the common sampling frequency S in the network is the signal processing engine. The sampling frequency is not limited, and diversity can be provided.

In the example of FIGS. 3A and 3B, the signal processing engine 30 of the music device 2 is of the sampling frequency non-synchronizable type (sampling frequency fixed type). However, as described above, some of the music devices 2 to which the music LAN expansion card 20 is attached include those of the sampling frequency synchronizable type (sampling frequency variable type). In this case, if the common sampling frequency S corresponding to the word clock WCLK is within the sampling frequency variable range in the signal processing engine 30, the operation clock of the signal processing engine 30 may be changed and controlled. It is not necessary to go through the sampling frequency converters to 22 not only when performing the operation but also when operating as a word clock slave. That is, the music LAN expansion card 20 is provided on the condition that the signal processing engine of the music device to which the music LAN expansion card 20 is attached is a sampling frequency variable type, and the common sampling frequency S is within the sampling frequency variable range. The operation as shown in FIG. 3C and FIG. FIG. 3C shows a case where the node (music device 2) is operating as a word clock master, and FIG. 3D shows a case where it is operating as a word clock slave. (C) is the same as the operation of the word clock master described in FIG. As shown in (d), in the case of a slave node, unlike the example of (b) described above, the signal processing engine 30 and the music LAN interface 21 directly transmit and receive waveform data without the sampling frequency converter 22 being interposed. . The music LAN interface 21 supplies the word clock generated based on the received word clock packet to the signal processing engine 30, and the signal processing engine 30 performs signal processing of the waveform data in synchronization with the supplied word clock. In this case, the signal processing engine 30 may synchronize the word clock by multiplying the supplied word clock to generate an operation clock, or the operation word may be fixed and the supplied word clock You may synchronize a word clock by performing signal processing by using a clock as a trigger. Since the sampling frequency of signal processing in the signal processing engine 30 is the same as the common sampling frequency S of isochronous transfer, the waveform data received by the music LAN interface 21 by isochronous transfer can be directly processed by the signal processing engine 30. On the contrary, the waveform data output from the signal processing engine 30 can be transmitted from the music LAN interface 21 by isochronous transfer as it is.
When the common sampling frequency based on the word clock WCLK is outside the frequency band that the signal processing engine 30 can handle synchronously, the same as described with reference to FIGS. 3 (a) and 3 (b). To work.

  Switching of operation according to whether the signal processing engine 30 is a sampling frequency synchronizable type or non-synchronizable type (switching between the operation mode of FIG. 3 (a) or (b) and the operation mode of (c) or (d)) The personal computer 1 (overall node) may determine the type and perform switching control, or the expansion card 20 may determine the device on which the expansion card 20 is mounted and perform operation switching control. In any case, such an operation switching control need not be performed on the terminal node side of the music device or the like.

  As described above, when a master / slave is designated for each node in this music system, the user performs a selection / designation operation on the personal computer 1 connected as one node on the network, and the master / slave of each node on the network is designated. Slave function designation and management can be performed collectively by the personal computer 1. Further, other appropriate functions on the expansion card 20 (for example, an effect imparting function such as a mixer function or equalizing) may be set and controlled from the personal computer 1. As described above, the configuration of the music system is configured such that various settings and the like of other “terminal nodes” (various music devices) are collectively managed and controlled by the “overall node” composed of the personal computer 1 via the communication function. Thus, for example, a processor for managing the master / slave function, a mixing function, and the like are not required for each node, and the configuration of the expansion card can be greatly simplified. In this way, various types of control related to network connection and data transmission / reception are performed from the outside by a central node such as a personal computer, thereby simplifying the structure of individual node devices such as synthesizers. Effects such as reduction occur. The expansion card according to this embodiment increases the flexibility and diversity of music system construction.

  As described above, according to the present invention, even when a music device having a signal processing engine with a fixed sampling frequency is connected to a network, a node other than the music device is used as a word clock master, and the fixed Any frequency other than the sampling frequency can be set as the common sampling frequency of the network. When the music device is a word clock master, its own sampling frequency can be used as the network common sampling frequency as it is. Furthermore, transmission / reception of the network, sampling frequency conversion, and the like are realized by an expansion card attached to the music device, and transmission / reception in the expansion card does not have an upper layer for network communication. Therefore, the music device can handle the expansion card as a normal waveform data input / output expansion card for inputting / outputting waveform data. In addition, when the signal processing means of the device is a sampling frequency variable type, even if the device is a slave device, the signal processing means may invalidate the sampling frequency conversion within a range in which the sampling frequency can be synchronized. it can.

The block diagram which shows the structural example of the music system which concerns on this invention, and the structural example of the node connected on the network. The figure which shows the example of a screen display regarding the connection setting between each node and the master / slave designation | designated processing of a word clock which are performed with a personal computer in the Example. The block diagram for demonstrating the sampling frequency conversion operation example when the said node is designated as the word clock master node or the word clock slave node.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Personal computer, 2 Music equipment, 3 Buses, 11 IEEE1394 standard interface (IEEE1394I / O), 12 Music LAN driver, 13 Music LAN interface part, 20 Music LAN expansion card, 21 Music LAN interface, 22 Sampling frequency converter (Fs) Converter), 23 control unit, 24 keyboard, 25 operator device, 26 display, 27 MIDI interface (MIDII / O), 28 waveform input / output interface (waveform I / O), 30 signal processing engine

Claims (4)

A signal processing apparatus that is one of a plurality of devices connected to a network, wherein each device can transmit or receive a packetized waveform signal to or from another device via the network. A transmission / reception unit capable of transmitting a synchronization packet to another device as a master device, and the other device responding to the synchronization packet received as a slave device The sampling frequency of the waveform signal in the transceiver is synchronized with the sampling frequency of the master device,
The signal processing device includes:
Signal processing means for processing a waveform signal at a predetermined sampling frequency;
Sampling frequency conversion means for converting the sampling frequency of the waveform signal exchanged between the signal processing means and the transmission / reception unit of the apparatus;
When the device is a master device, control is performed so that the waveform signal output from the signal processing device is transmitted from the transmission / reception unit without passing through the sampling frequency conversion unit, and the device is a slave device. In this case, the sampling frequency of the waveform signal output from the signal processing device is converted from the predetermined sampling frequency to the sampling frequency of the master device, and the waveform signal having the converted sampling frequency is transmitted from the transmitting / receiving unit. And a control means for controlling the signal processing. A signal processing apparatus that is one of a plurality of devices connected to a network, wherein each device can transmit or receive a packetized waveform signal to or from another device via the network. A transmission / reception unit capable of transmitting a synchronization packet to another device as a master device, and the other device responding to the synchronization packet received as a slave device The sampling frequency of the waveform signal in the transceiver is synchronized with the sampling frequency of the master device,
The signal processing device includes:
Signal processing means for processing a waveform signal at a predetermined sampling frequency;
Sampling frequency conversion means for converting the sampling frequency of the waveform signal exchanged between the signal processing means and the transmission / reception unit of the apparatus;
When the device is a master device, the control is performed so that the waveform signal received by the transmission / reception unit via the network is supplied to the signal processing unit without passing through the sampling frequency conversion unit,
When the device is a slave device, the sampling frequency of the waveform signal received by the transmitting / receiving unit via the network is converted from the sampling frequency synchronized with the sampling frequency of the master device to the predetermined sampling frequency. And a control means for controlling the waveform signal whose sampling frequency has been converted to be supplied to the signal processing means.   The transmission / reception unit is a transmission / reception unit having only a lower layer of functions to be included in a device connected to the network, and the transmission / reception unit includes the sampling frequency conversion unit and the control unit, and the signal processing device. The control relating to the communication mode of the expansion card, including the control of whether the signal processing device mounted with the expansion card is a master device or a slave device, is mounted on the network. The signal processing apparatus according to claim 1, wherein the signal processing apparatus is performed by a device having an upper layer corresponding to the lower layer among connected devices. The control means is further configured such that the signal processing means is a variable sampling frequency type and the sampling frequency of the signal processing means is the synchronized sampling even when the apparatus is a slave apparatus. 4. The sampling frequency conversion unit according to claim 1, wherein the synchronized sampling frequency is supplied to the signal processing unit and the sampling frequency conversion unit is invalidated on condition that the sampling frequency can be synchronized with the frequency. Signal processing device.

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