JP2003078537A - Equipment recognizing method and electronic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily recognize the type of data to be dealt with by equipment connected to an IEEE1394 type network from the other side equipment connected to the network. SOLUTION: At the time of controlling equipment connected through a digital communication bus capable of performing digital data communication, the transmission of a first command to inquire for the device type of the other party equipment connected through the digital communication bus and the transmission of a second command to inquire for a stream type to be dealt with by the equipment of the device type is executed, and the device type of the equipment and the stream type are recognized from a response to those first and second commands.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to, for example, IEEE.
(The Institute of Electrical and Electronics Engi
The present invention relates to an electronic device suitable for being applied to a device connectable to other devices by a digital communication bus called neers) 1394 system, and a control method applied to the electronic device.

[0002]

2. Description of the Related Art In recent years, video equipment and audio equipment such as video recorders, audio recorders, television receivers, tuners for receiving various broadcasts, audio amplifiers (hereinafter, these equipments are referred to as AV equipments or AV devices). ) Is connected to some kind of network, and video data and audio data are transmitted between the connected devices so that data can be transferred between the devices has been proposed and put into practical use.

For example, IEEE (The Institute of Ele)
ctrical and Electronics Engineers) A network via a 1394 serial data bus
A device that enables data transmission with V equipment has been developed. In this network, content data such as video data and audio data can be transmitted as stream data. In addition, a predetermined command (AV
It is also possible to remotely control AV equipment connected to the network by using / C Command Transaction Set: hereinafter referred to as AV / C command). Similarly, it is also possible to detect the state of AV equipment connected to the network by using the AV / C command.

In the case of the IEEE1394 system, a device (bus manager or the like) that manages communication in the network recognizes a device connected to the network, and assigns an address on the bus to the recognized device. I am doing it. Each device connected to the bus line and given an address is also called a node. By recognizing a device and assigning an address, it becomes possible to send data to the device and detect the state of the device. This kind of address assignment can be done when there is a change in the network configuration, that is, even if one device is added,
When removed, it is performed when a network initialization process called a bus reset is executed.

[0005]

By the way, the IEEE1
If it is assumed that AV equipment is connected to a 394 type bus line and video data is transmitted through the bus line, there are a plurality of types of video data that can be transmitted by this type of bus line. , It is necessary to unify the types of video data handled by the devices forming the network. Specifically, for example, as a standard of digital video data for consumer devices, a standard called DV system,
There is a standard called MPEG (Moving Picture Expers Group) system, and there are two types of video devices connectable to an IEEE 1394 bus line: a device that handles DV system video data and a device that handles MPEG system video data. There are types. In the case of the MPEG system, it is further divided into different compression system standards such as MPEG1, MPEG2 and MPEG4.

Unless the system conversion is performed, the DV system and the M system are used.
There is no data compatibility with the PEG system. For example, DV
The video equipment compatible with the video data of the system cannot handle the video data of the MPEG system, and vice versa.

Therefore, in order to connect a plurality of devices by an IEEE 1394 bus line to form a network and to transmit video data from one device to the other device by this bus line, the network must be DV. Video equipment for the system or MPEG
It is general to configure the network with video equipment for the system or to establish a network with only one of the standards.

However, as long as the device handles video data of any standard, as long as it is connectable to an IEEE 1394 bus line, the signal cables and ports connected as a bus line have exactly the same shape. There is a problem that the user cannot distinguish.

Conventionally, for example, a video deck that outputs DV system video data is connected to an MPEG system television receiver by an IEEE 1394 system bus line, and the video data output by the video deck is output. When trying to display it on the screen of the television receiver, the user confirms that nothing is displayed on the screen of the receiver, and for the first time it is determined that the device cannot connect the VCR and the receiver. Was there. When a user who has knowledge of the difference in the video system handling each device handles this, it is clear before connecting, but for a user who does not have the knowledge of the difference in the video system. However, it was not necessarily a convenient process.

Although the problem of transmitting the video data within the network has been described here, the same problem occurs when transmitting other stream data. That is, even when transmitting audio data and other various data, it is necessary that the data system be compatible between the transmitting device and the receiving device. There is a problem that cannot be done.

In view of the above points, the present invention has an object to make it possible to easily recognize the type of data handled by a device connected to this type of network from other devices connected to the network.

[0012]

According to the present invention, when controlling a device connected by a digital communication bus capable of communicating digital data, the device type of the partner device connected by the digital communication bus is inquired. The first command is transmitted, and the second command for inquiring the stream type handled by the device of that device type is transmitted,
The device type and stream type of the device are recognized by the response to the first and second commands.

By doing so, the stream type handled by the device of the other party connected by the digital communication bus can be known, and it can be determined whether the type of the stream data handled by the device matches or not. It becomes possible to judge whether the transmission of the stream data can be executed with the device.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below.
Description will be given with reference to the accompanying drawings.

FIG. 1 is a diagram showing an example of the connection configuration between the equipment of this example and a network. In this example, the television receiver 100 is used as a device that constitutes the network.
A hard disk recording device 200, a video tape deck 300, and a video camera 400 are prepared, and these are connected in order by cables 11, 12, and 13 that form an IEEE 1394 bus line. In addition,
Each video device 100, 20 that constitutes the network of this example
0, 300, 400 are at least MPEG and DV
This is a device that can handle video data of either one of the methods. Depending on the device, video data of both the MPEG system and the DV system can be handled.

Specifically, for example, the television receiver 100 has a configuration in which, when MPEG system image data is input, the input image data can be displayed. In addition, the hard disk recording device 2
With respect to 00, the video data of both the MPEG video data and the DV video data can be recorded on the disc and reproduced from the disc. Video tape deck 300
Has a structure capable of recording and reproducing MPEG video data. The video camera 400 has a configuration capable of recording and reproducing video data of the DV system. It should be noted that the MPEG system here refers to one specific type of MPEG system such as the MPEG2 system.

FIG. 2 is a block diagram showing a configuration example of the television receiver 100. The television receiver 100 of this example is a device called a digital television receiver that receives a digital broadcast signal and displays the received signal.

The television receiver 100 includes a tuner 101 for receiving digital television broadcasting,
The tuner 101 supplies digital broadcast data obtained by receiving a predetermined channel to the receiving circuit unit 102,
Decode. The broadcast data decoded by the receiving circuit unit 102 is supplied to the demultiplexing unit 103 to be separated into video data and audio data. The separated image data is supplied to the image generation unit 104, image receiving processing is performed, and the CRT drive circuit unit 105 causes the cathode ray tube (C
RT) 106 is driven to display an image. Also, the audio data separated by the demultiplexing unit 103 is supplied to the audio signal reproducing unit 107, audio processing such as analog conversion and amplification is performed, and the processed audio signal is supplied to the speaker 108 and output.

Further, the television receiver 100 is an IE
A bus communication unit 109 for communicating with an EE1394 bus line is provided so that communication can be performed via a bus line cable connected to a cable connection port unit 120 of the receiver 100. That is, IEEE13
The video data and the audio data obtained from the bus system of the 94 system to the bus communication unit 109 are supplied to the demultiplexing unit 103 so that the video can be displayed on the CRT 106 and the audio can be output from the speaker 108. . Further, the video data and the audio data received by the tuner 101 are supplied from the demultiplexing unit 103 to the bus communication unit 109, and the IE
It can be sent to the bus side of the EE1394 system.

When two or more bus line cables can be connected to the port unit 120, the bus communication unit 109 executes a relay process between the plurality of cables. That is, the data received at any one port section is repeated on the cable connected to the other port section so that the data signal is propagated to the entire bus line in the network.

The display processing in the television receiver 100 and the transmission processing via the bus communication unit 109 are executed under the control of the central control unit (CPU) 110. The CPU 110 has a memory 111, which is a ROM storing programs necessary for control, and a work RAM.
Is connected to the memory 112. Further, the operation information from the operation panel 113 and the control information from the remote control device received by the infrared light receiving unit 114 are stored in the CPU.
It is supplied to 110 to perform operation control corresponding to the operation information and control information.

When the bus communication unit 109 receives control data or the like via the IEEE 1394 bus, the data is supplied to the CPU 110, and the CPU 11
The control processing corresponding to 0 can be performed.

Further, the tuner 101 provided in the television receiver 100 of the present example is a tuner for digital broadcasting, and the tuner 101 has various types in addition to video data and audio data which are the data of the main broadcast program. It also receives data. Data other than video and audio received by the tuner 101 is supplied to the CPU 110 and accumulated in the memory 112 or the like.

The power supply circuit 115 provided in the television receiver 100 of this example is controlled by the CPU 110, and the receiver 10 is controlled.
Power is supplied to each circuit within 0. In this case, with respect to the bus communication unit 109 and the port unit 120, which are parts that perform communication via the IEEE 1394 bus, power control can be performed separately from other blocks, and the operating state and the non-operating state are set individually. I can do it. Specifically, for example, when the television receiver 100 is in a standby state, the bus communication unit 109 and the port unit 120 are set to be in a power-off state, or vice versa.
The bus communication unit 109 and the port unit 120 can be set to be always on even in the standby state.

Next, a state in which communication is performed in the network having the configuration shown in FIG. 1 will be described. As described above, in this example, a plurality of devices are connected by the IEEE 1394 bus line to form a network, and the configuration in which data is transmitted by the IEEE 1394 bus line will be described below.

FIG. 3 is a diagram showing a cycle structure of data transmission between devices connected by the IEEE 1394 system. In the IEEE 1394 system, data is divided into packets and transmitted in time division with a cycle having a length of 125 μS as a reference. This cycle is created by a cycle start signal supplied from a node (any device connected to the bus) having a cycle master function.

The isochronous packet secures a band (in units of time, called a band) necessary for transmission from the beginning of all cycles. Therefore, in isochronous transmission, data transmission is guaranteed within a fixed time. However, confirmation from the receiving side (acknowledgement: ack)
If a transmission error occurs, data will be lost if there is no protection mechanism. As a result of arbitration, the node that secures the bus sends asynchronous packets during the time when it is not used for isochronous transmission in each cycle. In asynchronous transmission, acknowledge and retry are used to ensure reliable transmission. , The transmission timing is not constant.

In order for a given node to perform isochronous transmission, that node must support the isochronous function. Moreover, at least one of the nodes corresponding to the isochronous function must have the cycle master function. Further, at least one of the nodes connected to the IEEE 1394 serial bus is
It must have the function of an isochronous resource manager.

The IEEE1394 system is ISO / IEC
It conforms to the CSR (Control & Status Register) architecture having a 64-bit address space defined by 13213. FIG. 4 is a diagram for explaining the structure of the address space of the CSR architecture. The upper 16 bits are a node ID indicating a node on each IEEE 1394, and the remaining 48 bits are used for designating an address space given to each node. The upper 16 bits are further divided into 10 bits of bus ID and 6 bits of physical ID (node ID in a narrow sense). A value in which all the bits are 1 is used for a special purpose, and 1023 buses and 63 nodes can be designated. The node ID is reassigned when the bus is reset. The bus reset occurs when the configuration of the device connected to the bus 1 changes. For example, when any one of the devices connected to the bus 1 is removed or it is recognized that a device is newly connected to the bus 1, the bus reset is executed.

Of the address space defined by the lower 48 bits, the space defined by the upper 20 bits is 204
An initialization register space (Initial Register Space), a private space (Private Space), and an initialization memory space (In) used for 8-byte CSR-specific registers and IEEE 1394-specific registers.
The space defined by the lower 28 bits is divided into an itial memory space), and the space defined by the upper 20 bits is an initialization register space, a configuration ROM (Configuration read only memor)
y), an initialization unit space used for a node-specific application, a plug control register (PCRs), and the like.

Here, the plug control register will be described. In the IEEE 1394 system, each node controls a data input / output, and each node is a PCR (Plug Control Register) which is a register used as a plug.
) Has. This is a materialization of the concept of a plug using a register in order to form a signal path that is logically similar to an analog interface.
PCR is an oPCR (output plug code) that represents an output plug.
ntrol Register), iPCR that represents the input plug (input
Plug Control Register). In addition, PCR is
It has a register oMPR (output master plug register) and an iMPR (input master plug register) indicating information of an output plug or an input plug unique to each device. Each device does not have multiple oMPRs and iMPRs, but the oPCR and iMPR corresponding to individual plugs
It is possible to have a plurality of PCRs depending on the capabilities of the device. The flow of isochronous data is controlled by manipulating the registers corresponding to these plugs.

FIG. 5 is a diagram showing an example of transmission using a plug. Here, a device (node) connected to an IEEE 1394 bus is used as an AV device (AV-device).
Shown as a, b, c. OMP of AV device a
OPCR in which the transmission rate and the number of oPCRs are defined by R

Among [0] to oPCR [2], the isochronous data whose channel is designated by oPCR [1] is AV
The data is transmitted from the oPCR [1] of the device c to the channel # 1 of the IEEE1394 serial bus. The AV device a is a channel # of the IEEE 1394 serial bus.
The isochronous data sent to 1 is read. Similarly, AV device b uses oPCR

The isochronous data is transmitted to the channel # 2 designated by [0], and the AV
The device a reads the isochronous data from the channel # 2 designated by iPRC [1].

In this way, data transmission is performed between the devices connected by the IEEE1394 serial bus, but in the system of this example, this IEEE1394 is used.
The AV / C command set defined as a command for controlling a device connected via the serial bus is used to control each device and determine the status. Next, the AV / C command set will be described.

First, the AV / s used in the system of this example
Subunit Identifier Descriptor (Subunit Identifier Descr) in C command set
The data structure of (iptor) will be described with reference to FIGS. FIG. 6 shows the data structure of the subunit identifier descriptor. As shown in FIG. 6, it is formed by a list of the hierarchical structure of the subunit identifier descriptor. The list represents, for example, a channel that can be received in the case of a tuner and songs recorded in the case of a disc. The list of the highest layer of the hierarchical structure is called a route list, and, for example, list 0 is the route for the list below it. The other lists are route lists as well. There are as many root lists as there are objects. Here, the object is, for example, each channel in digital broadcasting when the AV equipment connected to the bus is a tuner. Further, all the lists in one layer share common information.

FIG. 7 shows the general subunit descriptor (The General Subunit Identifier Descriptor).
or)) format is shown. The sub-unit descriptor describes the attribute information regarding the function as contents. Descriptor length (descriptor len
The gth) field does not contain the value of the field itself. Generation ID
Indicates the version of the AV / C command set, and its value is, for example, "00h" (h represents hexadecimal). Here, "00h" means that the data structure and command are version 3.0 of the AV / C general standard (General Specification), as shown in FIG. 8, for example. Also, as shown in FIG.
All values except "00h" are reserved and reserved for future specifications.

List ID size (size of list ID)
Indicates the number of bytes of the list ID. The object ID size (size of object ID) is the object I
The number of bytes of D is shown. The object position size (size of object position) indicates a position (number of bytes) in the list used for reference during control. Root object list number (number of ro
ot object list) indicates the number of root object lists. Root object list ID (root obj
ect list id) indicates an ID for identifying the highest root object list in each independent hierarchy.

Data length belonging to a subunit (subunit
The “dependent length” indicates the number of bytes of the data field (subunit dependent information) field belonging to the subsequent subunit. The data field belonging to the subunit is a field indicating information specific to the function. Data length specific to the manufacturer (manufacturer
Dependent length) indicates the number of bytes of the data (manufacturer dependent information) field specific to the subsequent manufacturer. The data unique to the manufacturer is a field indicating the specification information of the vendor (manufacturer). If there is no manufacturer-specific data in the descriptor, this field does not exist.

FIG. 9 shows an allocation range of the list ID shown in FIG. As shown in FIG. 9, “0000h
To 0FFFh "and" 4000h to FFFFh "
Is reserved as an allocation range for future specifications. "1000h to 3FFFh" and "10
000h to the maximum value of the list ID "is prepared for identifying the subordinate information of the function type.

Next, AV / used in the system of this example
The C command set will be described with reference to FIGS. FIG. 10 shows a stack model of the AV / C command set. As shown in FIG. 10, the physical layer 81, the link layer 82, the transaction layer 83, and the serial bus management 84 are
It conforms to EE1394. FCP (Function Contr
ol Protocol) 85 is based on IEC61883. The AV / C command set 86 complies with the 1394TA specifications.

FIG. 11 is a diagram for explaining commands and responses of the FCP 85 of FIG. FCP is IE
This is a protocol for controlling devices (nodes) on the EE1394 bus. As shown in FIG. 11, the controlling side is the controller and the controlled side is the target. The FCP command transmission or response is I
It is performed between the nodes using the write transaction of the asynchronous communication of EEE1394. The target that receives the data returns an acknowledge to the controller for confirmation of reception.

FIG. 12 is a diagram for explaining the relationship between the FCP command and the response shown in FIG. 11 in more detail. The node A and the node B are connected via an IEEE1394 bus. Node A is the controller and node B is the target. In each of the node A and the node B, a command register and a response register are prepared by 512 bytes each. As shown in FIG. 12, the controller transmits an instruction by writing a command message in the target command register 93. Conversely, the target transmits a response by writing a response message in the response register 92 of the controller. Control information is exchanged for the above two messages. The type of command set sent by FCP is described in CTS in the data field of FIG. 13 described later.

FIG. 13 shows the data structure of a packet transmitted in the asynchronous transfer mode of the AV / C command. The AV / C command set is a command set for controlling AV equipment, and CTS (command set ID) = “0000”. The AV / C command frame and the response frame are exchanged between the nodes using the FCP. In order not to burden the bus and AV equipment, the response to the command is 1
It is supposed to be done within 00 ms. As shown in FIG. 13, the data of the asynchronous packet is 3 in the horizontal direction.
It is composed of 2 bits (= 1 quadlet). The upper part of the figure shows the header part of the packet, and the lower part of the figure shows the data block. Destination
ination ID) indicates the destination.

CTS represents the ID of the command set, and CTS = “0000” in the AV / C command set.
Is. The C type / response field indicates the function classification of the command when the packet is a command, and the processing result of the command when the packet is a response. The commands are roughly divided into (1) a command (CONTROL) for externally controlling the function,
(2) Command to inquire status from outside (STAT
US), (3) Command for inquiring whether control command is supported from outside (GENERAL INQUI
RY (whether or not opcode is supported) and SPEC
IFIC INQUIRY (opcode and ope
(whether or not rands is supported)), (4) a command (NOTIFY) requesting to notify the state change to the outside.
4 types are defined.

The response is returned according to the type of command. The response to the control (CONTROL) command is "not implemented" (NOT I
MPLEMENTED, "Accept" (ACCEP
TED), "rejection" (REJECTED), and "provisional" (INTERIM). Status (STAT
The response to the US command includes “Not implemented” (NOT IMPLEMENTED), “Reject” (REJECTED), and “Transition” (INTRAN).
SITION), and "stable". Command to inquire whether command is supported from outside (GENERAL INQUIRY and SP
The response to ECIFIC INQUIRY is "Implemented" (IMPLEMENTED),
And "Not implemented" (NOT IMPLEME
NTED). The response to the command (NOTIFY) requesting to notify the state change to the outside is "not implemented" (NOT IMPLEMENT).
TED), "rejection" (REJECTED), "provisional"
(INTERIM) and "changed" (CHANGE)
There is D).

The subunit type is
It is provided to specify the function inside the device. For example, tape recorder / player (tape reccorder / playe)
r), tuner, etc. are assigned. In this subunit type, in addition to the function corresponding to the device, there is also assigned a BBS (bulletin board subunit) that is a subunit that discloses information to other devices. In order to make a determination when there are multiple subunits of the same type, the subunit ID (subu
nit id) for addressing. An operation code (opcode), which is an operation code, represents a command, and an operand (operand) represents a command parameter. Fields added as needed (ddit
ional operands) are also available. 0 data or the like is added after the operand as needed. Data C
RC (Cyclic Reduncy Check) is used for error checking during data transmission.

FIG. 14 shows a concrete example of the AV / C command. The left side of FIG. 14 shows a specific example of the command type / response. The upper part of the figure represents the command, and the lower part of the figure represents the response. "000
0 for control (CONTROL), "000"
"1" indicates status (STATUS), and "0010" indicates specific inquiry (SPECIFIC I).
NQUIRY), "0011" is Notify (NO
General Inquiry is assigned to TIFY) and “0100”. "0101 to 0111" are reserved and reserved for future specifications. Also, “1000” is not implemented (NOT INPLEMENTED), “1001” is accept (ACCEPTED), “1010” is reject (REJECTED), and “1011” is in transition (I
N TRANSITION), "1100" has implementation (IMPLEMENDED / STABLE), "11"
A state change (CHNGED) is assigned to 01 ”and a provisional response (INTERIM) is assigned to“ 1111 ”.
"1110" is reserved and reserved for future specifications.

The center of FIG. 14 shows a specific example of the subunit type. "000000" is a video monitor,
"00011" is a disc recorder / player, "0"
0100 "is a tape recorder / player," 0010 "
"1" is a tuner, "00111" is a video camera,
BBS (Bulletin Board Subunit) for "01010"
Subunit used as a bulletin board called "1"
1100 ”is a manufacturer-specific subunit type (Vender unique), and“ 11110 ”is a specific subunit type (Subunit type extended tonext byte).
Has been assigned. Although a unit is assigned to "11111", this is used when it is sent to the device itself, and is used, for example, to turn on / off the power. Note that subunit types other than those shown here may be defined.

The right side of FIG. 14 shows a specific example of the operation code (operation code: opcode). There is an opcode table for each subunit type, and here, an opcode in the case where the subunit type is a tape recorder / player is shown. In addition, an operand is defined for each opcode. Here, "00h"
Is a value specific to the manufacturer (Vender dependent), “50
"h" is search mode, "51h" is time code,
"52h" is ATN, "60h" is open memory, "61h" is memory read, "62h" is memory write, "C1h" is load, "C2h" is recording, "C3h" is Rewind is assigned to playback and "C4h".

FIG. 15 shows a concrete example of the AV / C command and the response. For example, when issuing a playback instruction to a playback device as a target (consumer), the controller sends a command as shown in FIG. 15A to the target. Since this command uses the AV / C command set, CTS = “0000”. ct
As the type (command type), a command (CONTROL) for controlling the device from the outside is used, so that c type = “0000” (see FIG. 14). Since the subunit type is the tape recorder / player, the subunit type = “00100” (see FIG. 14). id indicates the case of ID0, i
d = 000. The opcode becomes "C3h", which means reproduction (see FIG. 14). The operand is "75h" which means forward (FORWARD). Then, when reproduced, the target is shown in FIG. 15B.
Returns a response like this to the controller. here,
Since “accepted” is included in the response, the response is “1001” (FIG. 14).
reference). Except for the response part, the other parts are the same as those in FIG.

In the case of this example, the transmission processing described above is executed between the television receiver 100, the hard disk recording device 200, the video tape deck 300, and the video camera 400 shown in FIG. Stream data such as audio data can be transmitted between these devices, and by using AV / C commands,
It is possible to control other connected devices and detect their status.

Next, an example of a process in which the television receiver 100 of the present example recognizes another device in the network in the network thus connected will be described with reference to FIG. The process of recognizing other devices in the network is executed at the time of the network initialization process called so-called bus reset. This bus reset is executed when there is a change in the network configuration, that is, when one new device is connected to the network or even one connected device is removed. This bus reset is executed by monitoring the bias voltage applied to the cables forming the bus line.

FIG. 16 shows an example of processing of the device recognition state when the bus reset occurs. Here, when the television receiver 100 becomes the bus manager and detects the occurrence of the bus reset. An example of executing the device recognition process is shown in FIG. First, in step S1, when the CPU 110 in the television receiver 100 detects the occurrence of a bus reset, the television receiver 100 determines that the node which is an absolute ID given in advance to each device connected to the network. The unique ID is read out, and the read node unique ID is read out from the memory 112 connected to the CPU 110 of the television receiver 100.
Etc. Here, assuming the network configuration shown in FIG. 1, the devices 100, 200, 300, 4
The node unique ID of 00 is read and held.
For the television receiver 100, which is its own station, reading and holding of the node unique ID may be omitted.

By reading this node unique ID, the node ID which is the address in the network is given to the device of each node unique ID. After the node ID is assigned, the communication in the network basically identifies the sender and the receiver by the node ID. For example, in the packet header portion of the data shown in FIG. 13, the destination ID and the source ID can be arranged, the destination node ID is arranged in the destination ID, and the source ID is arranged in the source ID. Node IDs of are placed.
In FIG. 16, the process of assigning the node ID is omitted.

Then, the node unique IDs of all the devices connected to the network are read out and held, and when the node IDs are given, the device recognition process is performed thereafter using the AV / C command. Be seen. That is, FIG.
In step S2, the inquiry about the subunit type of each device is made to all the devices (nodes) that have recognized the connection. This subunit type is a type that corresponds to the function of the device that has already been described with reference to FIG.
GENERAL INQUIRY or SPECIFIC
(INQUIRY) command is sequentially sent to each device in the network, and the CPU 110 in the television receiver 100 confirms the mounted subunit type by a response to the command. The data of the subunit type that has been confirmed is held in the memory 112 connected to the CPU 110, for example. Not only this inquiry about the subunit type but also a more detailed distinction of the devices within the subunit type may be queried.

After inquiring all the devices in the network about this subunit type, in the next step S3, the CPU in the television receiver 100 is
110 inquires of all the devices in the network whose subunit type is confirmed whether or not the device handles MPEG system video stream data. The inquiry command, for example, is also used to inquire whether the device handles the MPEG video stream data. Alternatively, the inquiry may be made using another command. The data indicating whether or not the MPEG system is handled for each device confirmed by this command is stored in, for example, the memory 112 connected to the CPU 110.

Further, in the next step S4, the CPU 110 in the television receiver 100 determines whether or not all the devices in the network whose subunit type has been confirmed handle DV video stream data. To inquire. The inquiry command, for example, is also used to inquire whether the device handles the DV system video stream data. Alternatively, the inquiry may be made using another command. The data on whether or not the DV system is handled for each device confirmed by this command is also stored in the memory 112 connected to the CPU 110, for example.

In the case of this example, the television receiver 100 is a device compatible with the MPEG system.
The setting is made when data is stored so that a device compatible with the PEG system is preferentially handled.

Then, if each device is checked up to this point,
As shown in step S5, the communication state on the network shifts to the idle state and waits until some instruction is given.

FIG. 17 is a diagram showing an example in which the television receiver 100 collects information about each device in the network and stores it in the memory 112 in this way. In this example, I assigned to each device in the network
The node ID of D, the node unique id of an absolute ID of each device, the device type of the device type, and the stream type of the device are stored. The node ID may change when a bus reset occurs. As for the device type, the type of the device determined from the subunit type, such as a tape recording / reproducing device, a disk recording / reproducing device, a video camera recorder, etc., is stored. Note that FIG.
Types other than the subunit types classified in the example shown in FIG. 4 may be checked and stored by some processing.

In the example of FIG. 17, the stream type is the MPEG system and the DV system for the hard disk recording device 200 with the node ID 0, and the stream type is the MPEG system for the video tape deck 300 with the node ID 1. Yes, and for the video camera recorder 400 with a node ID of 2, the stream type is DV
It is a method.

In this way, by knowing the states of other devices connected to the network, the television receiver 1
Based on the stored data, the CPU 110 of 00 can know which device in the network can transmit the video data. That is, since the television receiver 100 of this example is a device compatible with the MPEG system, it is possible to receive or transmit MPEG system video data via an IEEE 1394 system bus line. A device capable of handling will understand before actually transmitting video data and the like.

For example, when it is considered that the television receiver 100 performs an operation of selecting a device as a transmission source of an input image, when the list of the selected devices is displayed, the television receiver 100 It is conceivable to process video equipment that cannot be handled by so that it cannot be selected. Specifically, for example, when a device selection screen is displayed, and in the case of the network configuration of this example, a screen as shown in FIG. 18 can be displayed. In this display, a list of names of video equipment connected to the network is displayed.

From this display, the television receiver 1
By selecting a desired device by operating a remote control device attached to 00 or a key arranged on the operation panel 113, an operation screen of the selected device is displayed, and an operation using the operation screen is performed. It becomes possible to control the corresponding device. During this control, for example, the above-mentioned AV
The / C command can be used to remotely control other devices and detect their status.

The device selection screen of FIG. 18 shows an example in which the hard disk recording device 200 is selected, and keys are displayed to perform a reproduction operation of the hard disk recording device 200.

Then, the place where the key is displayed is
By selecting with a cursor key or the like and performing a confirming operation, reproduction of the video data and audio data accumulated in the hard disk recording device 200 is started, and the reproduced video data and audio data are recorded in the MPEG system. Data of the television receiver 100 via the bus line 11
Be transmitted to. This data is used by the television receiver 100.
Is transmitted to the CR of the television receiver 100.
At T106, for example, as shown in FIG. 19, the reproduced video is displayed. Also, a voice output process is executed.

It is also assumed that an operation for selecting a video camera is executed while the device selection screen shown in FIG. 18 is displayed. In this case, since the video camera 400 connected to the network of the present example is a DV type device, it may be a signal type that the television receiver 100 cannot handle, as shown in the memory 112 connected to the CPU 110. It can be understood from the stored data shown in. Therefore, when an operation of selecting this video camera is performed, for example, as shown in FIG.
As shown in FIG.
6 displays “Data type cannot be received” to indicate that data from the selected device cannot be received. By performing such display, the user who sees the display can immediately recognize that the video camera is an incompatible device.

At the stage when the device selection screen shown in FIG. 18 is displayed, a display may be made such that the devices that can be handled by the television receiver 100 and the devices that cannot be handled are known. That is, for example, as a list display of the device names in the selection screen, the names of the hard disk recording device and the video tape deck, which are devices capable of handling MPEG data, are displayed in relatively bright colors or the like.
Regarding the display of the name of the video camera, which is a device that cannot handle the system data, it may be displayed in a relatively dark color so as to be distinguished.

In such a display mode as display colors, devices that cannot be handled and devices that cannot be handled are not distinguished from each other but displayed as characters or the like in the list of device names in the selection screen. It may be allowed to. By doing so, the correspondence or non-correspondence may be surely understood only by the user looking at the selection screen. Further, the data system to be handled, that is, system names such as MPEG system and DV system may be directly displayed in the list of each device.

When a video camera, which is a device that cannot handle MPEG data, is selected from the device selection screen, it may not be possible to positively indicate that the device is an incompatible device as shown in FIG. Instead, the operation screen of the device may be simply not displayed so that the user can know that the video camera is not compatible.

Further, the hard disk recording apparatus 200 of this example
With regard to the above, since both MPEG format data and DV format data can be handled, for example, when a video program recorded using the operation screen shown in FIG. 18 is selected, the selected video program is Although it may be considered that the video data is of the DV system, even in such a case, it is sufficient to display "It is an unreceivable data type" as shown in FIG.

In the above-described embodiment, the data of the data type handled by the equipment shown in FIG. 17 is stored in the memory 112 or the like in the television receiver 100 and used only for the control processing. But this Figure 17
The stored data shown in (1) may be displayed on the CRT 106 of the television receiver 100, for example.

Although the type of video data handled by each device in the network is confirmed by the process shown in FIG. 16, a response cannot be obtained by transmitting a command inquiring about the data type handled by the device. Therefore, when there is a device whose data type is unknown, the type of video data handled by the unknown device may be set by the user's input operation. That is, for example, the stored data shown in FIG.
It is also possible to display on the CRT 106 of 0 and display a screen for selecting which device of the MPEG system or the DV system handles the video data of the device whose data type is blank.

Further, in the above-described embodiment, the process of inquiring the stream data type shown in FIG. 17 is executed when the bus reset occurs when the network is initialized. At the time of occurrence, if the storage data shown in FIG. 17 already exists, the storage data is retained and the node I
It is also possible to update only the data that changes at the time of bus reset, such as D, and use the existing data before the bus reset for the stream type data. By doing this, when the bus is reset,
Only for the device newly connected to the network, the process of inquiring about the stream type in steps S3 and S4 in the process shown in FIG. 16 may be executed. For the device connected to the network before the bus reset, Such processing can be omitted, the processing required when a bus reset occurs is reduced accordingly, and the time until shifting to the idle state can be shortened.

Further, in the above-mentioned embodiment, the display on the television receiver 100 is premised on whether the counterpart device is compatible or non-compatible.
In the case of the network configuration shown in FIG.
The video data reproduced by the hard disk recorder 20
Since it is possible to record with 0, when the video camera 400 is selected as the output device and the hard disk recording device 200 is selected as the input device, the video camera is controlled by the television receiver 100. Output processing from 400 and hard disk recording device 2
It is also possible to perform control for executing the input processing at 00 to start data transmission between the corresponding devices via the bus line.

Further, in the embodiment described so far,
Although the network based on the IEEE 1394 standard bus is used, other networks may be used. In this case, each network includes Bluetooth (Bluetooth) in addition to networks using wired transmission lines.
: A wireless network such as a trademark may be used.

Further, as an example of the video equipment such as a television receiver and a VCR as the equipment connected by the network, the description has been made, but it is applicable to other video equipment, and the audio equipment handling audio signals can be connected to the network. It can also be applied to the case of transmitting audio data of various systems in combination. Further, the present invention is also applicable to a case where various kinds of electronic devices other than video devices and audio devices that can be connected to a digital communication bus line are used to form a network of this kind and to transmit data of various stream types.

[0077]

According to the present invention, it is possible to know the stream type handled by a counterpart device connected by a digital communication bus, and to determine whether the type of stream data handled with that device matches. Before transmitting the stream data to other devices, it can be surely confirmed that the stream data can be transmitted, and good transmission control without transmission error according to the stream type handled by each device in the network becomes possible. Become.

In this case, by displaying the stream type recognized by the response in a predetermined manner, the stream type that can be transmitted and processed can be easily understood from the display.

When the stream type recognized by the response matches among a plurality of devices on the network connected by the digital communication bus, the data of the corresponding stream type is transmitted between the matched devices. To
By starting via the digital communication bus, it is possible to reliably transmit only the data of the type handled by each device.

When the stream type recognized by the response does not match the stream type handled by another device on the network connected by the digital communication bus,
By displaying that the stream data of the stream types that do not match cannot be transmitted in a predetermined mode,
It is possible to easily recognize from the display that a device that handles data of a type that cannot be transmitted is connected.

Further, by setting the stream type handled by a device for which a response of the stream type is not obtained by the transmission of the second command by a predetermined input operation and displaying the stream type, the command is transmitted. Even if the device cannot reply the stream type in the response, it is possible to correctly set the stream type and the like during data transmission, as in the case of the device in which the stream type is obtained in the response.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a system configuration example according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration example of a device (television receiver) according to one embodiment of the present invention.

FIG. 3 is a timing diagram showing a data transmission state on an IEEE 1394 bus line.

FIG. 4 is an explanatory diagram showing an example of a structure of an address space of the CRS architecture.

FIG. 5 is an explanatory diagram showing a plug setting example at the time of transmission on an IEEE 1394 bus line.

FIG. 6 is an explanatory diagram showing an example of a data structure based on a hierarchical structure of descriptors.

FIG. 7 is an explanatory diagram showing an example data structure of a descriptor.

8 is an explanatory diagram showing an example of a generation ID in FIG. 7. FIG.

9 is an explanatory diagram showing an example of list IDs in FIG. 7. FIG.

FIG. 10 is an explanatory diagram showing an example of a stack model of an AV / C command.

FIG. 11 is an explanatory diagram showing an example of a relationship between commands and responses of AV / C commands.

FIG. 12 is an explanatory diagram showing an example of the relationship between commands and responses of AV / C commands in more detail.

FIG. 13 is an explanatory diagram showing an example of the data structure of an AV / C command.

FIG. 14 is an explanatory diagram showing a specific example of an AV / C command.

FIG. 15 is an explanatory diagram showing a specific example of a command and a response of an AV / C command.

FIG. 16 is an explanatory diagram showing an example of a device recognition state according to an embodiment of the present invention.

FIG. 17 is an explanatory diagram showing an example of device type and stream type data storage according to an embodiment of the present invention.

FIG. 18 is an explanatory diagram showing an example of a device selection screen according to an embodiment of the present invention.

FIG. 19 is an explanatory diagram showing an example of a reproduction screen according to the embodiment of the present invention.

FIG. 20 is an explanatory diagram showing an example of a device selection screen (when selection is inappropriate) according to an embodiment of the present invention.

[Explanation of symbols]

11, 12, 13 ... IEEE 1394 type bus line cable, 100 ... Television receiver, 101 ... Tuner, 102 ... Receiving circuit section, 103 ... Demultiplexing section, 1
04 ... video generation unit, 105 ... CRT drive circuit unit, 106
... CRT (cathode ray tube), 107 ... Audio signal reproducing section, 10
8 ... Speaker, 109 ... Bus communication part, 110 ... Central control unit (CPU), 111 ... ROM, 112 ... RA
M, 113 ... Operation panel, 114 ... Infrared receiver, 11
5 ... Power supply circuit, 120 ... Port part, 200 ... Hard disk recording device, 300 ... Video tape deck, 400 ...
Video camera

Claims (10)

[Claims] 1. A control method for controlling a device connected to a digital communication bus capable of communicating digital data, comprising transmitting a first command for inquiring a device type of a counterpart device connected to the digital communication bus. And a second command for inquiring about the stream type handled by the device of the above device type, and a control for recognizing the device type and the stream type of the above device in response to the first and second commands. Method. 2. The control method according to claim 1, wherein the stream type recognized by the response is displayed in a predetermined mode. 3. The control method according to claim 1, wherein when the stream type recognized by the response matches among a plurality of devices on a network connected by a digital communication bus, the matched devices are connected. Then, a control method for performing control to start transmission of data of a corresponding stream type via the digital communication bus. 4. The control method according to claim 1, wherein when the stream type recognized by the response does not match the stream type handled by another device on the network connected by the digital communication bus, the stream type does not match. The control method for displaying that the stream data cannot be transmitted in a predetermined manner. 5. The control method according to claim 1, wherein for a device for which a response of the stream type cannot be obtained by transmitting the second command, a stream type handled by the device is set by a predetermined input operation. A control method that can be displayed. 6. A communication means for communicating with another device via a digital communication bus, and the communication means for inquiring a device of a partner connected by the digital communication bus about a device type of the device. 1 command and a second command for inquiring the stream type handled by the device, and the communication means has a control means for determining the device type and the stream type from the responses to the first and second commands. Equipped electronic equipment. 7. The electronic device according to claim 6, further comprising a display unit, wherein the control unit controls the display unit to display the stream type recognized in the response in a predetermined manner. 8. The electronic device according to claim 6, wherein the control unit, when the stream type recognized by the response matches among a plurality of devices on a network connected by the digital communication bus, An electronic device that controls the transmission of data of the corresponding stream type between the matched devices. 9. The electronic device according to claim 6, further comprising a display means, wherein the control means recognizes that the stream type recognized by the response is a stream handled by another device on a network connected by a digital communication bus. An electronic device that controls to display in the predetermined mode on the display means that the stream data of the stream type that does not match cannot be transmitted when the type does not match. 10. The electronic device according to claim 6, further comprising: a stream type input means, wherein the control means outputs a stream from the input means to a device for which a stream type response cannot be obtained by transmission of the command. An electronic device that recognizes the input stream type as the stream type handled by the corresponding device when there is a type input.