JP2001156812A - Method and device for communication - Google Patents

Abstract

PROBLEM TO BE SOLVED: To process stream data on the data reception side without dropout when transmitting stream data through a network in an IEEE 1394 system or the like. SOLUTION: When stream data obtained in an output device 1 from a prescribed data source 1a is outputted to a prescribed network and is received by an input device 3, a command indicating transmission of stream data is sent from the output device 1, which preliminarily has registration about the input device 3, to the registered input device 3, and output processing of stream data from the data source 1a is started when a prescribed state like acknowledgment to the command is detected after sending of this command.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to, for example, IEEE 1
The present invention relates to a communication method and a communication apparatus applied when performing data communication between devices connected by a 394 system bus line.

[0002]

2. Description of the Related Art AV equipment capable of mutually transmitting information via a network using an IEEE 1394 serial data bus has been developed. When transmitting data via this bus, the isochronous transfer mode used for transmitting relatively large-capacity video data and audio data in real time, and still images, text data, control commands, etc., must be securely transmitted. Asynchronous transfer modes used for transmission are prepared, and a dedicated band is used for transmission for each mode.

In this case, a device that sends data on the bus is called a source device, and a device that receives data via the bus is called a destination device. A device that secures a transmission band on a bus between a source device and a destination device is called a controller or the like. The controller may also serve as a source device or a destination device.

[0004] In addition, various control data are transmitted in an asynchronous transfer mode from one device (controller) connected to the bus to another device (controlled device) using an IEEE1394 bus. It is also possible to remotely control the operation of the controlled device. For example, when a video deck (video recording / reproducing device) and a television broadcast receiving device are connected to an IEEE1394 bus, if the receiving device has a function as a controller, the video deck is controlled from the receiving device. Remote control becomes possible.

[0005] When such control data is transmitted, a control command transmission method called an AV / C command (AV / C Command Transaction Set) applied to, for example, AV equipment can be applied. Details of the AV / C command are disclosed at http://www.1394TA.org.

[0006]

In the case where stream data such as audio data and video data is transmitted between a plurality of devices connected by a bus, a process on the stream data received by the receiving device can be performed. Must be in place. Specifically, for example, when audio data or video data reproduced from one device is transmitted via a bus and recorded by the other device, the recording device is not ready to record. ,
When data transmission is started from the reproducing device, transmitted data cannot be recorded correctly from the beginning.

[0007] In addition, when processing other than recording is performed on data transmitted and received via the bus, there is a problem that the processing is not performed properly unless the processing is prepared.

An object of the present invention is to enable stream data processing on a data receiving side without loss when transmitting stream data in a network such as the IEEE 1394 system.

[0009]

SUMMARY OF THE INVENTION According to the present invention, when stream data obtained from a predetermined data source to an output device is output to a predetermined network, and the input device receives the stream data, registration of the input device is performed in advance. From a certain output device to its registered input device,
A command indicating transmission of stream data is sent, and when a predetermined state is detected after sending the command, a process of outputting stream data from a data source is started.

According to the present invention, output processing of stream data from a data source is started only when it is considered that transmission data can be correctly received and processed by an input device connected to a network. Become.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described.
This will be described with reference to the accompanying drawings.

An example of the configuration of a network system to which the present invention is applied will be described with reference to FIG. In this network system, a plurality of devices are connected via a serial data bus 9 of the IEEE1394 system. Here, an example is shown in which a device for processing audio data is connected. As shown in FIG. 1, an audio reproducing device 1, an audio recording and reproducing device 2, and an amplifier device 3 are connected to a bus 9. Each device 1, 2, 3
Is a device provided with an IEEE 1394 bus connection terminal, and is provided with a function that can be controlled by AV / C commands. In this case, at least one device having a function as a controller for performing transmission control on the bus 9 is connected to the bus 9. The device functioning as the controller may be one of the devices 1, 2, and 3, or may be another device (not shown) connected to the bus 9. In addition, AV devices other than audio devices and devices other than AV devices such as personal computer devices may be commonly connected to the bus 9.

Each of the devices 1, 2, and 3 has a functional unit defined by an AV / C command, which is provided between a subunit that executes processing for realizing each function and a bus 9 and an internal subunit. And a plug section for inputting and outputting data. That is, for example, the audio reproducing apparatus 1 includes a disk reproducing sub-unit 1a for reproducing audio data from a recording medium (disk), and the audio recording / reproducing apparatus 2 includes a disk sub-unit 2a for recording on a disk and reproducing from the disk. The amplifier device 3 includes a preamplifier unit 3a and a power amplifier unit 3c, which are subunits for processing audio data, and is connected to speakers 4L and 4R. Further, each of the devices 1, 2, 3 includes a plug unit 1b, 2b, 3b. A plurality of plugs are mounted on each of the plug portions 1b, 2b, and 3b, and are configured to be connectable to a plurality of channels on the bus 9. The relationship between the plug and the channel will be described later.

FIG. 2 shows an example of the internal configuration of the audio reproducing apparatus 2. The audio reproducing device 2 is an audio reproducing device that reproduces audio data recorded on a recording medium (optical disk) called a compact disk (CD).

That is, as shown in FIG. 2, a signal recorded on an optical disk 101 mounted on the apparatus is optically read by an optical pickup 102, and the signal read by the optical pickup 102 is supplied to a reproduction system circuit 103. Reproduction data (digital audio data) is obtained by performing reproduction processing such as data conversion and error correction in the reproduction system circuit 103. After the reproduced data is converted into an analog audio signal by the digital / analog converter 104, the signal is output from an analog output terminal 105 and supplied to an audio device or the like connected to the terminal 105. Also, the digital audio data obtained by the reproduction system circuit 103 is output from the digital output terminal 106. Further, the reproduction data obtained by the reproduction system circuit 103 is transferred to the IEEE 1394
The data is supplied to the interface unit 108 and can be transmitted as stream data to the connected bus 9.

The operation of reproducing from the disk is executed under the control of a central control unit (CPU) 107. Also,
The bus 9 from the IEEE1394 interface unit 108
Also, the transmission of data to and the reception of data from the bus 9 by the interface unit 108 are executed under the control of the CPU 107. The CPU 107 is connected to a memory 109 for storing data and the like necessary for control. Further, data necessary for performing control based on the AV / C command is also stored in the memory 109, and control of transmission and reception of the command is also performed by the CPU 1.
07. In addition, operation data of the operation unit 110 on which operation keys such as a reproduction key are arranged is supplied to the CPU 107.

Note that data relating to registration of a destination device, which will be described later, is stored in the memory 109 under the control of the CPU 107.
In a state where the destination device is registered in the memory 109, the CPU 107 can execute an auto function operation on the registered device. The auto function operation will also be described later. The number of destination devices that can be registered in this device is determined in advance, and one device or an arbitrary plurality of devices can be registered. The data registered in the memory 109 is erased when the bus 9 to which the device is connected is reset (when a so-called bus reset occurs). This bus reset is executed under the control of a controller that manages node IDs, for example, when any device connected to the bus 9 is disconnected from the bus or when a new device is connected to the bus. And a node ID or the like is newly assigned.

FIG. 3 shows an example of the internal configuration of the audio recording / reproducing apparatus 2. Here, the audio recording / reproducing apparatus 2 converts the audio data into a predetermined compression encoding method (ATRAC method: Adaptive Transform Acoustic C).
This is an audio recording / reproducing apparatus that encodes the data on a medium such as a magneto-optical disk called a mini disk (MD) and reproduces the data.

That is, as shown in FIG. 3, a signal recorded on a predetermined magneto-optical disk (or optical disk) 201 is optically read by an optical pickup 202, and the signal read by the optical pickup 202 is read by a recording / reproducing system. Circuit 20
3 for processing, and obtains ATRAC format reproduction data, and outputs the reproduction data to the ATRAC decoder 204.
, The original digital audio data is restored, the restored digital audio data is converted into an analog audio signal by a digital-to-analog converter 205, and then output from an analog output terminal 206. Supply to connected audio equipment. The digital audio data decoded by the ATRAC decoder 204 is output from the digital output terminal 207. Further, ATRAC decoder 2
ATRAC playback data (or A
Playback data decoded from the TRAC method)
The data is supplied to the EE1394 interface unit 212 and can be transmitted to the connected bus 9.

As a configuration of the recording system, an analog audio signal obtained at an analog input terminal 208 is converted into digital audio data by an analog / digital converter 209, and the converted audio data is converted to an ATR signal.
The audio data is supplied to the AC encoder 210 and is converted into audio data encoded in the ATRAC system by the ATRAC encoder 210. The audio data encoded in the ATRAC format by the ATRAC encoder 210 is supplied to a recording / reproducing system circuit 203 to be processed so as to be a recording signal to be supplied to the optical pickup unit 202, and this recording signal is recorded on the magneto-optical disk 201. Is done. Also, from bus 9 to IEEE
Digital audio data (digital audio data encoded in ATRAC format or digital audio data not compressed and encoded) supplied to the E1394 interface unit 212 is also supplied to the recording / reproducing system circuit 203 via the ATRAC encoder 210. Thus, the information is recorded on the magneto-optical disk 201.

The reproduction operation and the recording operation in these circuits are executed under the control of a central control unit (CPU) 213. Also, the IEEE1394 interface unit 21
CPU 2 also sends data from bus 2 to bus 9 and receives data from bus 9 at interface unit 212.
213 is executed. CPU 21
3 is a memory 21 for storing data and the like necessary for control.
4 is connected. Also, data necessary for performing control based on the AV / C command is stored in the memory 214.
The control of transmission and reception of commands is also processed by the CPU 213. Further, operation data of the operation unit 215 on which operation keys such as a recording key and a reproduction key are arranged is supplied to the CPU 213.

Note that data relating to registration of a destination device, which will be described later, is stored in the memory 214 under the control of the CPU 213.
When the destination device is registered in the memory 214, the CPU 213 can execute an auto function operation on the registered device. The auto function operation will also be described later. The number of destination devices that can be registered in this device is determined in advance, and one device or an arbitrary plurality of devices can be registered. The data registered in the memory 213 is deleted when the bus 9 to which the device is connected is reset (when a so-called bus reset occurs).

FIG. 4 shows an example of the internal configuration of the amplifier device 3. The amplifier device 3 here supplies a signal selected from the audio signals (analog audio signal or digital audio data) obtained at the input terminal unit 301 to the preamplifier unit 302, and performs sound field setting, sound quality adjustment, Performs various audio processing such as local amplification. The processing in the preamplifier 302 may be performed by digital processing or analog processing.
The output of the preamplifier 302 is an analog audio signal.

The audio signal processed by the preamplifier 302 is supplied to a power amplifier 303 to perform an amplification process with a relatively large output for driving a speaker, and the amplified audio signal is sent to a speaker connection terminal 30.
Supply to the speakers 4L and 4R via the 4L and 304R,
Output audio. Here, the amplifier device is for two-channel audio, but may be configured as an amplifier device for multi-channel audio having a larger number of channels.

The processing operations in these amplifier devices are executed under the control of a central control unit (CPU) 305.
The CPU 305 also transmits data from the IEEE 1394 interface unit 307 to the bus 9 and receives data from the bus 9 at the interface unit 307.
Is executed under the control of. The CPU 305 is connected to a memory 306 for storing data necessary for control. Further, operation data of the operation unit 308 in which operation keys and the like are arranged is supplied to the CPU 305, and input switching and sound quality setting are performed based on the operation data.

When audio data is received by the IEEE 1394 interface unit 307 via the bus 9, the audio data is supplied to the preamplifier unit 302, and the same processing as in the case of an audio signal obtained at the input terminal unit 301 is performed. Thus, audio can be output from the speakers 4L and 4R.

Note that data relating to an auto-function operation described later is stored in the memory 306 under the control of the CPU 305, and a command to execute the auto-function is transmitted from a source device in which this device is registered. Then, under the control of the CPU 305, the corresponding auto function is executed. However, in the case of the amplifier device 3 of the present example, whether or not the auto function operation is to be executed is determined by the operation unit 30.
It can be set on / off by the operation of 8, etc.
When set to off, even if a command to execute the auto function is transmitted from the source device,
The automatic function operation for the request is not performed. Hereinafter, this ON setting or OFF setting of the auto function operation is referred to as ON or OFF of the auto function state.

When a bus reset is applied to the bus 9 to which this device is connected, the device registered as a destination device is made to execute the destination device registration process again. It is.

In the amplifier device 3 of this embodiment, the power is turned on, the power is turned on, and the equipment is completely operated. In addition, the power is on standby, and only the control function blocks such as the CPU 305 are operated. It is also possible to do. Even in this standby state,
Determination of a command transmitted to the amplifier device 3 via the bus 9 and transmission of a response to the command can be executed. Further, when an operation of changing from the power-standby state to the power-on state is performed, after a time of about several seconds (for example, 5 seconds) required for stabilizing the operation of the power amplifier unit 303 and the like, the power-on state is started. It is in a state. This process of turning on the power is performed using, for example, a power relay connected to a power circuit.

In the connection example shown in FIG.
A connection between 2 and 3 is established by a bus 9, and audio data transmission between devices is also performed via the bus 9.

Next, the IEEE to which each of the above devices is connected
A state in which data is transmitted on the E1394 bus 9 will be described. FIG. 5 is a diagram showing a cycle structure of data transmission of devices connected by IEEE1394. IE
In EE1394, data is divided into packets and
The data is transmitted in a time division manner on the basis of a cycle having a length of 25 μs. This cycle is created by a cycle start signal supplied from a node having a cycle master function (any device connected to the bus). The isochronous packet secures a band (a time unit but called a band) necessary for transmission from the beginning of every cycle. Therefore, in isochronous transmission, transmission of data within a certain time is guaranteed. However, if a transmission error occurs, there is no protection mechanism and data is lost. Asynchronous transmission, in which the node that has secured the bus as a result of arbitration, sends out asynchronous packets during the time that is not used for isochronous transmission in each cycle, ensures reliable transmission by using acknowledgments and retries. However, the transmission timing is not constant.

In order for a given node (device) to perform isochronous transmission, the node must be compatible with the isochronous function. At least one of the nodes corresponding to the isochronous function must have a cycle master function. In addition, IEEE13
At least one of the nodes connected to the 94 serial bus must have the function of an isochronous resource manager. The device having the function of the isochronous resource manager corresponds to the controller described above.

FIG. 6 is a diagram showing the relationship between plugs, plug control registers, and isochronous channels necessary for performing data transmission on the bus. AV device (AV-device) connected to the bus
e) 11 to 13 are connected by an IEEE 1394 serial bus. OPCR in which the transmission speed and the number of oPCRs are defined by the oMPR of the AV device 13

[0]
~ OPCR [2], the isochronous data of which channel is designated by oPCR [1] is IEEE1
394 Serious Bus Channel # 1 (channel)
# 1). IPCR in which the transmission speed and the number of iPCRs are defined by the iMPR of the AV device 11

Of [0] and iPCR [1], the input channel # 1 has the transmission speed and iPCR

[0], the AV device 11
Reads the isochronous data transmitted to channel # 1 of the IEEE 1394 serial bus. Similarly,
The AV device 12 has an oPCR

The isochronous data is transmitted to the channel # 2 specified in [0], and the AV device 11
The isochronous data is read from the channel # 2 specified in [1].

Using the channel secured in this way, the data transmitted from the output plug of the data transmission source device to the bus is set to be received by the input plug of the data reception destination device. You. The process of setting a channel and a plug and establishing a connection is executed under the control of a predetermined device (controller) connected to the bus.

In this manner, data transmission is performed between devices connected by the IEEE 1394 serial bus. In the system of this embodiment, the IEEE 1394 serial bus is used.
Using an AV / C command defined as a command for controlling a device connected via a serial bus, control of each device, determination of a state, and the like can be performed. The data used in the AV / C command will be described below.

FIG. 7 shows a data structure of a packet transmitted in the asynchronous transfer mode of the AV / C command. The AV / C command is a command set for controlling AV equipment, and is CTS (command set ID).
= “0000”. AV / C command frames and response frames are exchanged between nodes.
The response to the command is basically performed within 100 ms so as not to burden the bus and the AV equipment. As shown in FIG. 7, the data of the asynchronous packet is 32 bits in the horizontal direction (= 1 q
udlet). The upper part in the figure shows the header part of the packet, and the lower part in the figure shows the data block. The destination ID indicates a destination.

CTS indicates the ID of the command set. In the AV / C command set, CTS = "0000"
It is. The type / response field indicates the functional classification of the command when the packet is a command, and indicates the processing result of the command when the packet is a response.

The commands are roughly divided into (1) a command for controlling the function from outside (CONTROL), (2) a command for inquiring the state from outside (STATUS),
(3) A command (GENERAL INQUIRY (o
pccode support) and SPECIFIC
INQUIRY (opcode and operand
s)), and (4) four types of commands (NOTIFY) for requesting external notification of state changes are defined.

The response is returned according to the type of the command. Responses to the CONTROL command include NOT IMPLEMENTED (not implemented), ACCEPTED (accept), and REJECT.
ED (rejection) and INTERIM (provisional response)
There is. The response to the STATUS command includes NOT IMPLEMENTED, REJECTE
D, IN TRANSITION, and S
There is TABLE (stable). GENERAL INCU
Responses to IRY and SPECIFIC INQUIRY commands include IMPLEMENTED
(Implemented), and NOT IMPLEMEN
There is a TED. The response to the NOTIFY command includes NOTIMPLEMENTED, REJECT
ED, INTERIM and CHANGED (changed). Note that commands and responses other than those shown here may be defined.

The subunit type (subunit type) is provided to specify a function in the device, and for example, a tape recorder / play.
er, tuner, etc. are assigned. In order to determine when a plurality of subunits of the same type exist, addressing is performed using a subunit id as a determination number. opcode represents a command, and opera
nd represents a command parameter. Addit
The ionic operands are fields added as necessary. The padding is also a field added as needed. data CRC (Cyc
Like Redundancy Check) is used for error checking during data transmission.

FIG. 8 shows a specific example of the AV / C command. FIG. 8 (A) shows ctype / respons
The example of e is shown. The upper part of the figure represents a command, and the lower part of the figure represents a response. "000
CONTROL for "0" and STATU for "0001"
S, "0010" is SPECIFIC INQUIR
NOTIFY is assigned to Y and “0011”, and GENERAL INQUIRY is assigned to “0100”. “0101 to 0111” are reserved and reserved for future specifications. "1000" has NOT I
NPLEMENTED, "1001" is ACCEPT
ED, “1010” has REJECTED, “101”
“1” is IN TRANSITION, “1100” is IMPLEMENTED / STABLE, “110”.
"1" is CHNGED, "1111" is INTERI
M has been assigned. “1110” is reserved and reserved for future specifications.

FIG. 8B shows a subunit type.
The example of e is shown. “00000” is Video
o Monitor, “00011” is Disk r
recorder / Player, "00100" is T
ape recorder / Player, "0010
“1” is Tuner and “00111” is VideoC
amera, "11100" has Vendor uni
que and “11110” have Subunit type
The extended to next byte is assigned. Note that a unit is assigned to “11111”, which is used when it is sent to the device itself, for example, power on / off.

FIG. 8C shows a specific example of the opcode. Opco for each subunit type
de table exists, and here, subunit
type is Tape recorder / Player
The opcode in the case of is shown. Also, opcode
Operand is defined for each e. here,
“00h” is VENDOR-DEPENDENT,
SEACHMODE for "50h", T for "51h"
IMECODE, ATN for "52h", OPEN MIC for "60h", READ MI for "61h"
C, WRITE MIC for "62h", LOAD MEDIUM for "C1h", RECORD for "C2h"
D, PLAY for "C3h", WIND for "C4h"
Is assigned.

The devices connected to the bus are controlled using the AV / C command defined as described above, and data transmission between the devices connected to the bus is performed based on the control. . Here, in this example, an input device (destination device) capable of inputting stream data
Causes the output device (source device) to register an input device, and the output device controls transmission of stream data and processing of the transmitted stream data to the registered input device. Prepare a command. In the following description, a process of registering an input device is referred to as a destination registration process, and a process of transmitting a command to the registered destination device and executing a transmission and a control related to the transmission is referred to as an auto function. Called processing.

FIG. 9 shows an example of the data configuration of [opcode] and [operand] of the AV / C command transmitted at the time of destination registration processing. This data is arranged in the packet shown in FIG. The command type is a control command [CONTROL
L], and in the [opcode] area, a command requesting the corresponding registration process [AF DESTI
NATION REGISTRY] data. The area of [operand (0)] is undefined here, and for example, predetermined specific data is arranged. In the area of [operand (1)], data of the subunit type of the destination device and the subunit ID of the destination device are arranged. In the [operand (2)] area, data of the unit type or subunit type of the source device and the unit ID or subunit ID of the source device are arranged. Usually, a unit type and a unit ID are specified. In the [operand (3)] area, [re
registration state] data is arranged. The registration state data is data indicating whether to execute destination registration or to cancel destination registration.

FIG. 10 shows [opcode] of the AV / C command transmitted when executing the auto function process.
e] and [operand] are shown, and this data is arranged in the packet shown in FIG. The command type is [CONTROL], and [opco
In the area of [de], a command requesting the corresponding processing is provided [AF SELECTION REQUEST].
Is arranged. The area of [operand (0)] is undefined here, and for example, predetermined specific data is arranged. In the area of [operand (1)], the subunit type of the destination device and the subunit ID of the destination device are displayed.
Is arranged. In the [operand (2)] area, the data of the subunit type of the source device and the subunit ID of the source device are arranged. [Op
erand (3)] area has [unit out]
put plug]. As the data of the unit output plug, when a unit (or a subunit) of the source device wants to specify an output plug, data for specifying the output plug is arranged.

Next, an example of the operation when the destination registration is executed will be described with reference to the flowchart of FIG. In the flowchart shown in FIG. 11, the processing of steps S11 to S15 on the left side is processing on the destination device side (that is, the processing on the device side performing a registration request), and the processing of steps S21 to S26 on the right side is
This is a process in the source device (that is, a process in the device that registers the destination device).

First, in the destination device, when there is a request for setting the auto function function, it is determined whether the setting request is a registration request (step S11).
If it is a registration request, registration request data is prepared (step S12). If it is not a registration request, the registration is canceled, and the registration cancellation data is prepared (step S
13). As these data, for example, data of the AV / C command shown in FIG. 9 is prepared, and [o
perand (3)], is the registration state data a destination registration request?
It is determined whether the data is destination registration cancellation data. The destination registration command thus prepared is transmitted to the registration target device (step S14). The destination device waits until a response to the transmitted control command is received.

In any of the source devices, its own node I
When D receives the destination registration command with the received ID (step S21), it determines the data of [operand (3)] of the command and determines whether it is a registration request (step S22). If the request is a registration request, it is determined whether registration of the destination device can be performed by the own station (step S23).

The determination here is, for example, whether or not the own station can register the destination device for the auto function operation, and if the registration is possible, the number of destination devices that can be further registered. Then, the number of destination devices currently registered is determined, and it is determined whether new registration is possible. For example, if three destination devices can be registered, and two devices are currently registered, and there is a new destination device registration, it is determined that registration is possible. Also, if the registration of the currently registered device is deleted and new registration is possible, it is determined that registration is possible.

If it is determined that the registration is possible, the data such as the node ID, subunit type, and subunit ID of the transmission source added to the transmitted command is retained, and it is indicated that the registration request is acknowledged. ACCEPTE
D] (Step S2)
4). If it is determined that the registration is not possible, preparation is made to return a [REJECTED] response indicating that the registration request is rejected (step S25). Then, any one of the prepared responses is returned (step S26), and the registration process ends.

If it is determined in step S22 that the request is not a registration request, it means that a deregistration command has been transmitted, and it is determined whether the destination device specified by the command has already been registered ( Step S27). Here, in the case where the device has been registered, a process of invalidating the registered content in the device (that is, deletion of data held for the device) is performed, and [ACCEPTED] indicating that the user acknowledges the cancellation of the registration. Preparations are made to return a response (step S28). If there is no registration for the destination device, it indicates that registration cannot be canceled [REJECTED].
Prepare to send back the response (step S2)
9). Then, one of the prepared responses is returned in step S26, and the deregistration process ends.

When the response transmitted in step S26 is received by the destination device (step S15), the destination device also ends the registration process.

When the registration process is executed on the source device side in this way, in step S23, it is determined whether or not the registration is possible. When the registration of a new registration request is possible when the registration of a new registration request is possible while the set number of destination devices have already been registered, Alternatively, upon receiving a new registration request, one of the registered destination devices may be deleted under certain conditions. When deleting the registration of the destination device already registered under the certain condition, for example, the oldest registered destination device is deleted. Alternatively, the registration of a device that is used least frequently as a destination device in the past may be deleted.

Next, an example of the operation when the source device (for example, the disk reproducing apparatus 1 or the disk recording / reproducing apparatus 2) executes the auto function operation will be described with reference to the flowchart of FIG. Here, the auto function operation is executed when, for example, an operation of reproducing a disk is performed by the disk reproducing device 1.
In the flowchart shown in FIG. 12, the processes in steps S41 to S58 on the left side are processes on the destination device side (that is, processes on the device side performing the auto function operation), and the processes in steps S31 to S39 on the right side.
Is a process in the source device (that is, a process in the device that issues a request for the auto function operation).

First, in the source device (disc reproducing device 1), when there is an operation of a reproducing operation button or the like and it is desired to execute the auto function operation on the registered destination device, the reproduction of the audio data from the disk is reproduced. After setting a standby state called a pause state or the like, an AF select request command is transmitted to the corresponding destination device (step S3).
1). By setting the reproduction standby state, when there is a reproduction start instruction, it is possible to immediately start the reproduction of the disc.

When this command is received by the destination device (step S41), it is determined whether the auto function state is on or off (step S42), and the auto function state is set so that the auto function can be executed. At the time of (case), it is determined whether the power state of this device is a standby state or a power-on state (step S43). If it is in the standby state, a process of turning on the power is performed (step S44).

When it is determined that the power is on in step S43 and when the power is turned on in step S44, a connection for audio data transmission between the source device and the destination device is established. The processing is executed under the control of the destination device (step S45). In this process, it is determined whether or not a connection can be established (step S46). When it is determined that the connection can be established (that is, when it is determined that there is a vacancy in the transmission band on the bus 9), it is determined in advance from the reception of the command. It is determined whether a response can be returned within a predetermined time (for example, within 100 ms) (step S47). If the response cannot be returned within that time, the response is a provisional response [INTERI
M] A response is returned (step S48).

After it is determined in step S47 that a response can be returned within a predetermined time, or after a provisional response has been returned in step S48, it is determined whether the connection establishment processing has been completed (step S49) and step S44. Then, it is determined whether or not a power-on instruction has been issued (step S50) and whether or not the power relay has been turned on (step S51). When each of the conditions is satisfied, preparations are made to return an [ACCEPTED] response, which is a response to the control command (step S52), and the prepared response is transmitted to the source device (step S54). .

If the power supply relay is not turned on in step S51 while the power supply is instructed in step S50, a predetermined time after the power supply is instructed (this time is the time required for turning on the power supply). Longer than:
When 6 seconds have elapsed here, [A] in step S52
The process proceeds to preparation for returning a [CCEPTED] response. If this time has not elapsed, the process returns to step S51. Also, when it is determined in step S50 that the power-on instruction has not been issued, the [ACCEPT
ED] Move on to preparation for returning a response.

If it is determined in step S42 that the auto function state is set to the off state, the control command is rejected [REJECTE
D] Prepare to return a response (step S5
5) Then, the prepared response is transferred to step S54 and transmitted. Similarly, when it is determined in step S46 that the connection cannot be established, the control command is rejected [REJECTE
D] Prepare to return a response (step S5
6) Then, the prepared response is transferred to step S54 and transmitted.

If the connection is not established in step S49, it is determined whether or not the connection cannot be established (step S57). If the connection cannot be established, the control command is rejected [REJECTED]. A preparation is made to return a response (step S58), and the prepared response is transferred to step S54 and transmitted. Step S57
When it is determined that the connection cannot be established, the process returns to step S49.

Although only the connection establishment process has been described as a process in the destination device, other processes necessary for outputting audio data transmitted from the source device may be simultaneously executed. good. For example, the input selection in the preamplifier unit may be processed to select the corresponding audio data.

Next, the processing when the source device receives a response will be described. After transmitting the command in step S31, it is determined whether or not any response has been received (step S32). The response is a provisional response [INTERI
M] It is determined whether the response is a response (step S33),
If the response is not an [INTERIM] response, processing based on the received response (ie, [ACCEPTE]
[D] response or [REJECTED] response) (step S37), start reproduction in the source device (step S38), and reproduce the audio data reproduced from the disc at the start of the reproduction. Output from 1. In this case, [ACCEPT
ED] When a response is returned and the audio data can be transmitted via the bus 9, the audio data is transmitted to the amplifier device 3 or the like via the bus 9, and the transmitted audio data is transmitted to the amplifier device 3 or the like. Output processing. When the [REJECTED] response is returned and audio data cannot be transmitted via the bus 9, the reproduced audio signal is transmitted to the amplifier device 3 or the like through another transmission path such as an analog transmission path.

When it is determined in step S33 that the [INTERIM] response, which is a provisional response, has been received, it is determined whether 10 seconds have elapsed since the response was received (step S34). Is performed (step S35), and the reproduction device 1 outputs the audio data reproduced from the disc at the start of the reproduction.

It is determined whether or not the next response has been received within a period of 10 seconds after receiving the [INTERIM] response (step S36). The process moves to S37, where processing based on the received response is performed, and reproduction from the disc is executed in step S38.

If no response can be received in step S32, it is determined whether or not the state in which the response cannot be received has continued for 120 ms from the transmission of the command (step S39).
If not, the process returns to step S32.
If 120 ms has elapsed since the transmission of the command, the process proceeds to step S38 to execute reproduction from the disc.

By executing the auto-function processing in this manner, when a disk playback operation is performed by the disk playback device 1, a connection for audio data transmission between the disk playback device 1 and the amplifier device 3 is established. Once established, disc playback will begin,
The audio output from the speaker connected to the amplifier device 3 has no break from the beginning and is output well. In this case, since the control process is executed only between the source device and the destination device registered in advance, the control is not performed between unspecified devices connected to the bus, and the Only the control accompanying the data transmission can be reliably performed.

When a command for requesting an auto function is sent from the source device, the source device sets the playback pause state of the disc and the like, and when the stream data can be transmitted, the transmission is immediately started. Is performed, stream data can be transmitted immediately when the destination device is ready. In addition, even if it is not a playback pause,
In the case of a playback device that can be immediately brought into the playback state by a playback start instruction, there is no need to perform such processing.

The destination device (amplifier device 3) of this embodiment requires several seconds (5 seconds in the above example) to change from the power standby state to the power on state. Here, when transmitting the audio data from the source device, when the destination device is in the power standby state, the power is set to ON, and after a time longer than the time required for turning on the power has elapsed,
The response is sent back to the source device. For this reason, the reproduction of the audio data on the source device is started after the power of the destination device is turned on and the transmitted audio data can be processed, and the destination device is in the power standby state. Even if it takes time to process the received stream data for possible reasons,
This has the effect that stream data transmitted from the source device can be processed without loss from the beginning.

When performing the process of waiting for the time from the power standby state to the power on state, a temporary response is sent as a response from the destination device to the source device, and then a formal response is sent. Since the transmission is performed, the source device can also wait for a relatively long time, such as starting reproduction, based on the provisional response.

Further, even when a response to the command cannot be detected on the source device side, the reproduction is started when a predetermined condition is satisfied. It is possible to perform a process of transmitting and outputting audio data via the PC. For example, in this example, the response to the command is set to be returned within 100 ms.
In the flowchart shown in FIG. 12, when a response cannot be received within 120 ms after the command is transmitted in step S39, a reproduction start process is performed, and when control via the bus 9 cannot be executed for some reason. However, the output processing of the reproduced audio can be performed.
Also, after receiving the provisional response in step S33, if the formal response cannot be received for 10 seconds, the reproduction start process is performed, and the time when the power supply is considered to be turned on at the destination device side is considered. If no response is returned after
Output processing of the reproduced audio can be performed.

Further, when a connection for audio data transmission cannot be established on the bus 9, that is, when a response rejecting a control command is received, reproduction is started. If audio can be transmitted through a channel, audio can be output well.

On the destination device side,
Whether or not to execute the operation by the auto function
Since the on / off setting can be made, it is possible to give priority to the operation on the operation unit or the like of the destination device.

In the above-described embodiment, the audio data reproduced from the disk reproducing apparatus 1 is transmitted to the amplifier apparatus 3. However, the audio data reproduced from the disk reproducing apparatus 1 is recorded and reproduced on the disk. The same processing can be performed when the data is transmitted to the device 2 for recording, or when the audio data reproduced from the disk recording / reproducing device 2 is transmitted to another device. For example, when the present invention is applied to a case where audio data reproduced from the disk reproducing apparatus 1 is transmitted to the disk recording / reproducing apparatus 2 for recording, audio data can be recorded satisfactorily without a loss from the beginning.

In the above-described embodiment, the processing performed by the amplifier device 3 as a destination device includes
The case where the auto function operation is executed based on a request from a source device connected via the bus 9 has been described. For example, an audio source source is provided in the amplifier device 3 and an output process of audio data from the source source is performed. The same processing may be performed when performing the above. For example, as an amplifier device, when a tuner for receiving radio broadcasts and the like, a disc playback unit, etc. are built in, and an operation of selecting the output of those source sources is performed,
Similar processing may be performed inside the amplifier device.

Further, in the above-described embodiment, the processing in the case where the device provided with the data source of the audio data is used as the source device and the audio data from the source device is transmitted to the destination device (amplifier device) has been described. However, a device provided with another data source may be used as a source device, and the auto function operation in the destination device may be executed under the control of the source device. For example, when transmitting video data from a data source of video data (such as a video playback device) to a receiver, a video recording device, a video editing device, or the like, a similar auto function operation may be executed. Also, stream data other than audio data and video data may be transmitted by the same processing.

In the above-described embodiment, the IEEE standard is used.
Although the case of the network configured by the 1394 bus has been described, the present invention can be applied to a case where similar data transmission is performed between devices having other network configurations.

Further, in the above-described embodiment, the function for performing the above-described processing is set in each device. However, a program for performing the same processing is distributed to the user using some kind of providing medium, and The user may install the program stored in the medium in a computer device connected to a bus (such as an IEEE 1394 bus) and execute the same function. In this case, the providing medium may be a physical recording medium such as an optical disk or a magnetic disk, or a medium provided to the user via a communication means such as the Internet.

[0080]

According to the communication method described in claim 1,
From the input device connected to the network and registered in advance, when a response indicating that the transmission device acknowledges sending the stream data is detected by the output device, the output process of the stream data from the data source is started. By doing so, stream data can be transmitted only between devices registered in advance on the network after confirming the response to the transmission request, and the stream data output from the data source , The receiving process can be performed reliably.

According to the communication method described in claim 2, in the invention described in claim 1, the process of outputting stream data from a data source is a process of reproducing from a recording medium, so that the stream data is transmitted over a network. The reproduction from the data source can be controlled at an accurate timing.

According to the communication method of the third aspect, in the second aspect of the invention, the recording medium is set in the standby state for reproduction until a response is obtained from the output device.
When there is a response from the input device, the data source is immediately set to the reproduction state, and the reproduced stream data can be transmitted.

According to the communication method described in claim 4, in the invention according to claim 1, when the input device outputs a response indicating that the command is accepted, the data recording unit provided in the input device stores the input data. By performing the recording start processing or the recording standby processing, the recording processing of the stream data received by the input device can be performed almost simultaneously with the start of the recording of the stream data, and the recording can be performed without loss from the head of the transmitted data. become able to.

According to the communication method described in claim 5, in the invention described in claim 1, when an input device receives a command indicating that stream data is transmitted from an output device that has not made a registration request. Also sends a response indicating that it understands the command to the output device, and starts output processing of stream data from the data source at the output device, so that the input device and the output device Even when the registration process cannot be performed, the same control as when the registration process is performed can be performed.

According to the communication method described in claim 6, in the invention described in claim 1, it is possible to selectively set whether or not to make a response indicating that the command is accepted by the input device. When the input device is set not to send a response indicating that it understands, the input device sends a response indicating that the command is rejected to the output device, so that the input device can perform remote control from another device. It is possible to set so that a recording operation or the like is not performed.

According to the communication method described in claim 7, in the invention according to claim 1, the number of input devices that can be registered is determined in advance by the output device, and the output device registers the determined number of input devices. In a certain state, when there is a new input device registration request, by responding to the registration request indicating that it is rejected, the countermeasures when there are registration requests exceeding the specified number are registered first. Can be performed satisfactorily while giving priority to

According to the communication method described in claim 8, in the invention described in claim 1, the number of input devices that can be registered is determined in advance by the output device, and the output device registers the determined number of input devices. In a certain state, when there is a new input device registration request, the oldest registered input device is deregistered, and the newly requested input device is registered, so that a registration request exceeding the specified number Can be satisfactorily dealt with while giving priority to a device that has a new registration request.

According to the communication method of the ninth aspect, in the first aspect of the invention, when the network is reset, the registration data on the input device in each output device is deleted, thereby resetting the network. After this, it is possible to reliably prevent erroneous determination of registration data due to a change in device ID or the like.

According to the communication method described in claim 10,
When the input device cannot immediately process the received stream data, a provisional response is sent to the input device, and the output device receiving the provisional response waits for the transmission of the stream data from the data source. By doing
The transmission of the stream data is not started in a state where the input device cannot process the received data, and the data loss on the receiving side can be effectively prevented.

According to the communication method described in claim 11,
In the invention according to claim 10, when the input device can process the received stream data, a response indicating that the command is acknowledged is transmitted to the output device, and the response indicating that the command is acknowledged is transmitted to the output device. By starting transmission of stream data from the data source when it is received,
When the input device is ready, the transmission of stream data starts immediately.

According to the communication method described in claim 12,
In the invention according to claim 10, when a response indicating that the command is acknowledged cannot be received within a predetermined time after the provisional response is received by the output device, transmission of stream data from the data source is started. This makes it possible to cope with the case where the input device is ready to receive the stream data but cannot respond to the command for some reason.

According to the communication method described in claim 13,
In the invention according to claim 10, when no response can be received by the output device for a predetermined time, the transmission of stream data from the data source is started, so that the input device is ready to receive the stream data. It is possible to respond when there is no response at all for some reason.

According to the communication device of the present invention,
When a response indicating that the transmission of the stream data is acknowledged can be detected from the input device connected to the network and registered in advance, the process of outputting the stream data from the data source is started. The stream data can be transmitted only to the device registered in advance after confirming the response to the transmission request, and the stream data can be reliably transmitted to the other device.

According to the communication device described in claim 15,
In the invention according to claim 14, when a transmission request is made under the control of the communication control means, the recording medium prepared as a data source is set to a standby state for reproduction, and when a response to acknowledge the transmission request is detected, the standby state is set. By performing control to change the state to the reproduction state, reproduction control of the recording medium prepared as a data source can be favorably performed in conjunction with transmission.

According to the communication device of the sixteenth aspect,
In the invention according to claim 14, the number of devices that can be registered in the communication control means is set to a predetermined number, and when a new registration request is made in a state where the set number of devices are registered, the registration request is made. By performing control to transmit a rejection response to a request, a response to a registration request exceeding a predetermined number can be satisfactorily performed while giving priority to the device registered first.

According to the communication device of the seventeenth aspect,
In the invention according to claim 14, the number of devices that can be registered in the communication control means is set to a predetermined number, and when a new registration request is issued in a state where the set number of devices are registered, the oldest registered device is registered. By canceling the registration of the registered device and controlling the registration of a new device that has a new registration request, if there is a registration request exceeding the specified number, the device that has a new registration request has priority. Can be performed well.

According to the communication device of the eighteenth aspect,
In the invention according to claim 14, when the communication control means detects that the network has been reset, by deleting the data of the registered device, the device ID is changed after the network is reset. Erroneous determination of registration data can be reliably prevented.

According to the communication device described in claim 19,
When a provisional response to a stream data transmission request can be detected from a pre-registered input device connected to the network, the output of the stream data from the data source is set to a standby state, thereby waiting for the other device. The transmission of the stream data is not started in a state where the data received on the side cannot be processed, and the loss of the transmission data can be effectively prevented.

According to the communication device of the present invention,
In the invention according to claim 19, the communication control means changes a data source from a standby state to an output state of stream data when detecting a response to acknowledge a transmission request after detecting a provisional response, When the other device is ready, transmission of stream data can be started immediately.

According to the communication device described in claim 21,
20. The communication control means according to claim 19, wherein when the communication control means cannot detect a response to acknowledge the transmission request within a predetermined time after detecting the provisional response, the data source is changed from the standby state to the stream data output state. By changing to the above, it is possible to cope with a case where the partner device is ready to receive the stream data but cannot respond to the command for some reason.

According to the communication device described in claim 22,
20. The communication control means according to claim 19, wherein when no response can be detected within a predetermined period of time, the data source is changed from the standby state to the output state of stream data, whereby the other party's device is changed for some reason. Can respond to no command at all.

According to the communication device described in claim 23,
When there is a request to transmit stream data from a pre-registered output device connected to the network, settings are made so that stream data can be received, and a response based on the setting is performed. Thus, stream data is transmitted from the partner device, and the situation where the stream data is transmitted in a state where the stream data cannot be received can be prevented.

According to the communication device described in claim 24,
In the invention according to claim 23, as a response to be output under the control of the communication control means, a provisional response is output immediately after the detection of the transmission request, and when the received stream data can be processed, the transmission request is acknowledged. By outputting a response, the stream data is transmitted at the stage when the received data can be processed correctly,
Received data processing can be performed satisfactorily without loss from the beginning.

According to the communication device described in claim 25,
In the invention according to claim 24, the setting for processing the stream data is a setting for changing from the power standby state to the power on state, and the communication control means acknowledges the transmission request when the power is on. By outputting a response, it is possible to prevent data from being transmitted during a state in which the apparatus does not start up from the power standby state, and after a state in which the apparatus can be received after being turned on in the power on state, Data will be transmitted.

According to the communication device described in claim 26,
According to the twenty-third aspect of the present invention, a response to be output under the control of the communication control means can be selectively rejected based on a predetermined operation so that transmission requests can be rejected. It is possible to set so that the receiving operation cannot be performed.

According to the communication device described in claim 27,
In the invention according to claim 23, when a reset is applied to the network to which the input / output means is connected, a command to be registered from the input / output means is transmitted again under the control of the communication control means, so that the network is reset. You can automatically re-register when you do.

[Brief description of the drawings]

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

FIG. 2 is a block diagram illustrating an example of an internal configuration of the audio reproduction device according to the embodiment of the present invention;

FIG. 3 is a block diagram illustrating an example of an internal configuration of the audio recording / reproducing device according to the embodiment of the present invention;

FIG. 4 is a block diagram illustrating an example of an internal configuration of the amplifier device according to the embodiment of the present invention;

FIG. 5 is an explanatory diagram showing an example of a cycle structure of data transmission on an IEEE 1394 bus.

FIG. 6 is an explanatory diagram showing an example of a connection using an IEEE 1394 bus.

FIG. 7 is an explanatory diagram showing a configuration example of data transmitted by an AV / C command.

FIG. 8 is an explanatory diagram showing an example of a command and a response of an AV / C command.

FIG. 9 is an explanatory diagram showing an example of data at the time of destination registration according to an embodiment of the present invention.

FIG. 10 is an explanatory diagram showing an example of data at the time of an auto function request according to an embodiment of the present invention.

FIG. 11 is a flowchart illustrating a processing example at the time of destination registration according to an embodiment of the present invention.

FIG. 12 is a flowchart illustrating a processing example of an auto function operation according to an embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Audio reproduction apparatus, 1a ... Disk subunit, 1b ... Port part, 2 ... Audio recording and reproduction apparatus, 2
a: disk subunit, 2b: port, 3: amplifier, 3a: preamplifier, 3b: port, 3c
Power amplifier section, 4L, 4R ... speaker, 9 ... IEEE
1394 bus, 108, 212, 307... Bus interface, 107, 213, 305... Central control unit (CPU)

Claims (27)

[Claims] 1. A communication method for outputting stream data obtained from a predetermined data source to an output device to a predetermined network, and receiving the stream data at an input device, comprising the steps of: To the registered input device, a command indicating that the stream data is transmitted is sent, and when a response indicating that the command is acknowledged is received by the output device, the stream data from the data source is received. Communication method to start output processing. 2. The communication method according to claim 1, wherein the output processing of the stream data from the data source is a reproduction processing from a recording medium. 3. The communication method according to claim 2, wherein the recording medium is in a reproduction standby state until the output device obtains the response. 4. The communication method according to claim 1, wherein when the input device outputs a response indicating that the command is accepted, the data recording unit provided in the input device starts recording of the input data. A communication method that performs recording standby processing. 5. The communication method according to claim 1, wherein the input device outputs an output device that has not made a registration request.
Even when a command indicating that the stream data is sent is received, a response indicating that the command is acknowledged is sent to the output device, and the output device starts processing for outputting stream data from the data source. The communication method to let. 6. The communication method according to claim 1, wherein the input device can selectively set whether or not to make a response indicating that the command is acknowledged, and indicates that the user acknowledges the command. A communication method in which the input device sends, to the output device, a response indicating that the command is rejected when the device is set not to respond. 7. The communication method according to claim 1, wherein the number of input devices that can be registered in the output device is determined in advance, and the new number of input devices is registered in the output device. A communication method in which, when a registration request for an input device is made, a response indicating that the registration request is rejected is sent. 8. The communication method according to claim 1, wherein the number of input devices that can be registered in the output device is determined in advance, and the new number of input devices is registered in the output device. A communication method in which, when an input device registration request is issued, the oldest registered input device is deregistered, and a newly requested input device is registered. 9. The communication method according to claim 1, wherein when the network is reset, registration data relating to an input device at each output device is deleted. 10. A communication method for outputting stream data obtained from a predetermined data source to an output device to a predetermined network, and receiving the stream data at the input device, comprising: If a command indicating that the stream data is transmitted is sent to the registered input device, and if the input device cannot immediately process the received stream data, a provisional response is sent to the input device. A communication method in which the output device receives the provisional response and waits for transmission of stream data from the data source. 11. The communication method according to claim 10, wherein when the input device can process the received stream data, a response indicating that the command is accepted is transmitted to the output device. A communication method for starting transmission of stream data from the data source when a response indicating that the data source is acknowledged is received. 12. The communication method according to claim 10, wherein after receiving the provisional response from the output device, when the response indicating that the command is acknowledged cannot be received within a predetermined time period, the data is output. A communication method that starts sending stream data from a source. 13. The communication method according to claim 10, wherein when no response is received by the output device during a predetermined time, transmission of stream data from the data source is started. 14. A communication device connected to a predetermined network, comprising: input / output means for communicating with other devices in the network; a data source for obtaining stream data transmitted from the input / output means; When the entry / output unit detects a command to enable transmission of stream data from the data source to a predetermined device in the data received, the device that transmits the command is registered, and the registered device is registered. When transmitting stream data from the input / output means, a predetermined transmission request is made, and when a response that approves the transmission request is detected,
A communication device comprising: communication control means for outputting stream data from the data source and starting transmission of the stream data from the input / output means. 15. The communication device according to claim 14, wherein when a transmission request is made under the control of the communication control means, the recording medium prepared as the data source is placed in a reproduction standby state, and the transmission request is acknowledged. A communication device that performs control to change the standby state to the reproduction state when a response to the response is detected. 16. The communication device according to claim 14, wherein the number of devices that can be registered in said communication control means is set to a predetermined number, and a new registration request is issued in a state where said set number of devices are registered. When there is a communication device, the communication device controls transmission of a rejection response to the registration request. 17. The communication device according to claim 14, wherein the number of devices that can be registered in the communication control means is set to a predetermined number, and a new registration request is issued in a state where the set number of devices are registered. When there is a communication device, the communication device performs control for canceling registration of the oldest registered device and registering a device newly requested to be registered. 18. The communication device according to claim 14, wherein when the communication control means detects that the network has been reset, the data of the registered device is deleted. 19. A communication device connected to a predetermined network, comprising: input / output means for communicating with other devices in the network; a data source for obtaining stream data transmitted from the input / output means; When the entry / output unit detects a command to enable transmission of stream data from the data source to a predetermined device in the data received, the device that transmits the command is registered, and the registered device is registered. Communication for making a predetermined transmission request when transmitting stream data from the input / output means to the input / output means, and, when detecting a provisional response to the transmission request, setting the output of the stream data from the data source to a standby state to stand by A communication device comprising a control unit. 20. The communication device according to claim 19, wherein when the communication control unit detects a response to acknowledge the transmission request after detecting the provisional response, the communication control unit changes the data source from a standby state to a stream data transmission mode. A communication device that changes to an output state. 21. The communication device according to claim 19, wherein when the communication control means cannot detect a response to acknowledge the transmission request within a predetermined time after detecting the provisional response, the communication control means switches the data source. A communication device that changes from a standby state to a stream data output state. 22. The communication device according to claim 19, wherein when no response is detected by the communication control means within a predetermined time, the data source is changed from a standby state to a stream data output state. apparatus. 23. A communication device connected to a predetermined network, comprising: input / output means for communicating with another device in the network; and a command for registering the predetermined device so that stream data can be transmitted. In addition, when a transmission request from the registered device is detected, a setting is made so that the stream data received by the input / output unit can be processed, and a response based on the setting is output. A communication device comprising communication control means. 24. The communication device according to claim 23, wherein a temporary response is output immediately after the detection of the transmission request as a response to be output under the control of the communication control means, so that the received stream data can be processed. A communication device that outputs a response to the transmission request when the transmission request is acknowledged. 25. The communication device according to claim 24, wherein the setting for processing the stream data is a setting for changing from a power standby state to a power on state, and wherein the communication control means is in a power on state. A communication device that outputs a response to the transmission request when the transmission request is acknowledged. 26. The communication device according to claim 23, wherein a response to be output under the control of the communication control means can be selectively rejected based on a predetermined operation. 27. The communication device according to claim 23, wherein when the network to which the input / output unit is connected is reset, a command to register from the input / output unit is transmitted again under the control of the communication control unit. Communication device.