JP2005176251A - Data transfer method, data transfer apparatus, and control program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a data transfer method by which a required isochronous band is secured and digital video data is transmitted in the case of transmitting the digital video data of any data format. <P>SOLUTION: The data format of the transferred digital video data is discriminated when transferring the digital video data recorded on a recording medium (step S302), and the data is transmitted by broadcast connection using the 63rd channel when the discriminated data format is an SD format (step S303). The data is transmitted through point-to-point connection using other channel than the 63rd channel when the data format requires a greater band than the band required for the SD format (step S304). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a data transfer method and data transfer device for transferring record information recorded on a recording medium, and a control program for executing the control method of the data transfer device.

  In general, the data format of digital video data includes a DV (Digital video) standard SD method (hereinafter referred to as an SD format), an SDL method (hereinafter referred to as an SDL format) that employs a higher compression rate than the SD method, DV standard HD system (hereinafter referred to as HD format), MPEG (Moving Picture Experts Group) standard (hereinafter referred to as MPEG format), etc., and digital video data recorded in such a data format as a recording medium A technique for reproducing and transferring data using a digital interface is conventionally known.

  In recent years, IEEE Std 1394-1995 (reference: IEEE Std 1394-1995, IEEE Standard for a High Performance Serial Bus, Institute of Electrical and Electronics Engineers, Inc.) and IEEE Std 1394a-2000 (reference) A digital interface (hereinafter referred to as IEEE 1394 interface) conforming to IEEE Std 1394a-2000, IEEE Standard for a High Performance Serial Bus-Amendment 1) is known. The IEEE 1394 interface uses the isochronous transfer mode to transfer SD format digital video data, SDL format digital video data, HD format digital video data, or MPEG format digital video data to the outside at high speed. can do.

  Isochronous transfer is performed via a channel set on the IEEE 1394 serial bus, and the connection form to the channel of each node (data transmission device such as an AV device) connected to the IEEE 1394 serial bus is a broadcast connection. (Broadcast connection) and point-to-point connection. The broadcast connection and point-to-point connection are described in IEC 61883-1 (reference: IEC 61883-1, Consumer audio / video equipment-Digital interface-Part 1: General). Detailed description thereof is omitted.

  In the IEEE 1394 interface, a node having an isochronous transfer function among a plurality of nodes connected to the IEEE 1394 serial bus is set as an isochronous resource manager (IRM), and this IRM is the isochronous transfer. The resources and resources related to the network are managed, and the bandwidth and channels necessary for isochronous transfer are allocated.

  In order to output the playback data to the outside using the IEEE1394 interface when playing back the digital video tape in which the digital video data of the various data formats described above is played back, a band necessary for isochronous transfer must be secured. become.

  For example, when a digital video cassette tape in which the SDL format and the SD format are recorded is played back and the playback data is transmitted to the outside using the IEEE1394 interface, the SDL format is required when the SDL format is played back. Since the isochronous band to be transmitted is at least 260 bytes, a 260-byte isochronous band is secured for transmission. Next, when playback of the SD format is started, since the isochronous bandwidth required by the SD format is at least 500 bytes, it cannot be transmitted with the current 260 bytes. Therefore, a 500-byte isochronous bandwidth is secured and transmitted. . Such processing has a problem that it is necessary to repeatedly secure a band for each format of digital video data to be reproduced.

In view of this, a method has been proposed in which the maximum bandwidth required for the reproduced video is ensured and any data format is transmitted using the maximum bandwidth (see Patent Document 1). In this proposal, for example, even when the SDL format is being reproduced, a bandwidth of 500 bytes of the SD format that requires the maximum bandwidth recorded on the recording medium is secured in advance and the SD format is transmitted. Of course, when the SDL format is transmitted, it is possible to avoid the annoyance of reserving the bandwidth every time the data format of the digital video data to be reproduced is changed by transmitting the data while securing the bandwidth of 500 bytes. Yes.
JP 2002-281451 A

  However, in the conventional proposal, the maximum isochronous band must always be ensured even when digital video data in any of SD format, SDL format, HD format, and MPEG format is output to the outside. Therefore, for example, among the nodes on the IEEE 1394 serial bus, the node (A) capable of transmitting the SD format and the HD format transmits the digital video data in the SD format via the broadcast connection using the conventional proposal. If the other node (B) on the same bus tries to transmit the HD format digital video data through the broadcast connection by 63 channels, the node (B) uses the IRM to determine how much the node (A) is isochronous. Since it is impossible to know whether the bandwidth is secured and only the amount of isochronous bandwidth actually used for transmission by the node (A) can be known, reliable transmission cannot be performed.

  In view of the above-described conventional problems, the present invention provides a data transfer method, a data transfer apparatus, and a control program that can perform transmission while ensuring a necessary bandwidth when transmitting digital video data of any data format. The purpose is to provide.

  In order to achieve the above object, according to the data transfer method of the present invention, in the data transfer method for transferring the record information recorded on the recording medium, the determination step for determining the data format of the record information to be transferred, and the determination step If the determined data format is the first data format, a first transfer step of transferring using the first connection method, and the data format determined by the determining step is the first data format In the case of the second data format that requires a larger bandwidth than the required bandwidth, a second transfer step of performing transfer using the second connection method is performed.

  Further, in the data transfer device of the present invention, in the data transfer device for transferring the record information recorded on the recording medium, the determination unit for determining the data format of the record information to be transferred, and the data format determined by the determination unit are In the case of the first data format, the first transfer means for transferring using the first connection method, and the data format determined by the determination means is more than the bandwidth required for the first data format. In the case of the second data format that requires a large bandwidth, the second transfer unit performs transfer using the second connection method.

  The control program of the present invention is a computer-readable control program for executing a control method of a data transfer device for transferring record information recorded on a recording medium, and the data format of the record information to be transferred A determination step, a first transfer step of performing transfer using the first connection method when the data format determined by the determination step is a first data format, and a determination by the determination step A second transfer step of performing transfer using the second connection method when the data format is a second data format that requires a larger bandwidth than that required by the first data format It is characterized by having.

  According to the present invention, it is possible to perform transmission while ensuring a necessary band even when recording information of any data format is transmitted.

  Embodiments of a data transfer method, a data transfer apparatus, and a control program according to the present invention will be described with reference to the drawings. The data transfer apparatus of this embodiment is applied to a digital video camera, for example.

  FIG. 1 is a schematic diagram showing a schematic configuration of a data transfer system including a data transfer apparatus according to an embodiment of the present invention.

  In the figure, reference numerals 101 and 105 denote digital video cameras (DVC) which are examples of the data transfer apparatus of this embodiment. The DVC 101 is connected to the digital television (DTV) 103 via the IEEE 1394 cable 102, and the DVC 105 is connected to the digital television 103 via the IEEE 1394 cable 104.

  FIG. 2 is a block diagram showing an example of the internal configuration of the DVCs 101 and 105 shown in FIG.

  Reference numeral 201 in the drawing denotes a digital video cassette, which is a recording medium on which a plurality of digital video data having different data formats are recorded. A system controller 202 stores a program such as a control program according to the processing procedure of the flowchart of FIG. 3 described later, and controls the operation of the digital video camera by executing this program.

  A reproduction unit 203 reproduces digital video data from the digital video cassette 201.

  A display unit 204 displays the digital video data supplied from the reproduction unit 203 on a display such as a liquid crystal display. Reference numeral 205 denotes an operation unit having a playback button and the like. An IEEE 1394 interface 206 has a function of converting digital video data into an isochronous packet defined by IEEE STD 1394-1995 and outputting the packet to the connector 207.

  Next, the operation of the DVCs 101 and 105 will be described.

  When playing back the digital video data recorded in the digital video cassette 201, the user first presses a play button on the operation unit 205. Then, the system controller 202 detects that the playback button has been pressed, and starts the playback operation. Digital video data reproduced from the digital video cassette 201 is sent to the IEEE 1394 interface 206 and the display unit 204.

  The display unit 204 displays the digital video data supplied from the playback unit 203 on a display. At the same time, the digital video data sent to the IEEE 1394 interface 206 is converted into an isochronous packet defined by IEEE STD 1394-1995 and transmitted to the digital television 103 connected to the connector 207.

  Next, in the data transfer system shown in FIG. 1, the DVC 101 transmits the digital video data in the digital video cassette 201 in a situation where the DVC 105 is transmitting SD format data through a broadcast connection using 63 channels. The method of this embodiment in this case will be described with reference to the flowchart of FIG.

  Here, in each node connected to the IEEE 1394 serial bus, a plurality of virtual input plugs (iPCR) and output plugs (oPCR) can be set, and when data transmission / reception is controlled on the IEEE 1394 serial bus. Is done through this virtual plug. A broadcast connection is a connection of one input plug (Input Plug Control Register: hereinafter abbreviated as iPCR) or output plug (Output Plug Control Register: hereinafter abbreviated as oPCR) in a specific node to one channel. Therefore, the situation in which the DVC 105 transmits the digital video data in the SD format through the broadcast connection using 63 channels is that one output plug (oPCR) set in the DVC 105 is connected to the 63 channels. This shows a situation in which digital video data in SD format is being transmitted.

  As shown in FIG. 4, the data structure (32 bits) of the oPCR includes an area “online” indicating whether the output plug connection is on or off, and the number of broadcast connections using the output plug. Broadcast connection counter area “bcc” indicating the number of point-to-point connections using the output plug, point-to-point connection counter area “pcc”, and extension spare area “rsv” ”, An area“ channel ”indicating the number of the channel used for isochronous transfer, an area“ dr ”indicating the transfer speed, an area“ overheadID ”indicating the amount of overhead added to the data to be transferred, and transfer every cycle An area “payload” indicating the amount of data to be processed; It is configured.

  As shown in FIG. 5, the data structure (32 bits) of the iPCR includes an area “online” indicating whether the connection of the input plug is on or off, and the number of broadcast connections using the input plug. Broadcast connection counter area “bcc” indicating the number of points, point-to-point connection counter area “pcc” indicating the number of point-to-point connections (to be described later) using the input plug, and extension An area area “rsv” indicating a spare area, an area “channel” indicating a channel number used for isochronous transfer, and an expansion reserved area “reserved” are configured.

  Here, the point-to-point connection is a connection form in which one output plug (oPCR) in a specific node and one input plug (iPCR) in another node are associated with one channel.

  First, in step S301, when the playback button of the operation unit 205 of the DVC 101 is pressed, in the next step S302, the system controller 202 that has detected the playback command changes the format of the digital video data to be played back to the playback unit 203. Confirm.

  In step S302, when the digital video data to be reproduced is in the SD format, the DVC 101 performs the following processing to transmit the broadcast connection using 63 channels. That is, the system controller 202 informs the IEEE 1394 interface 206 that the transmission format is the SD format, and in response to this, the IEEE 1394 interface 206 checks the “payload” (see FIG. 4) in the oPCR of the DVC 105. Confirm that the DVC 105 is transmitting the SD format.

  The IEEE 1394 interface 206 of the DVC 101 sets “bcc” in its own iPCR to “0”. Further, the IEEE 1394 interface 206 changes the “bcc” of the OVC of the DVC 105 from “1” to “0” to make the connection disconnected, sets the “bcc” of its own oPCR to “1”, and makes the connection connected. The oPCR “channel” is set to “63” and the SD format is transmitted.

  On the other hand, if the digital video data to be played back is in the HD format that requires a band larger than that required by the SD format in step S302, point-to-point using a channel other than 63 channels. The DVC 101 performs the following processing in order to transmit by connection.

  That is, the system controller 202 of the DVC 101 informs the IEEE 1394 interface 206 that the transmission format is the HD format. The IEEE 1394 interface 206 checks “payload” in the oPCR of the DVC 105, and the DVC 105 transmits the SD format. Make sure.

  Next, the IEEE 1394 interface 206 of the DVC 101 sets “bcc” in its own iPCR to “0”. Further, the IEEE 1394 interface 206 changes the “bcc” of the OVC of the DVC 105 from “1” to “0” so that the connection is not connected, and the isochronous bandwidth for the SD format used for the isochronous resource manager (IRM). And return 63 channels.

  Here, in the IEEE 1394 interface, the bandwidth and channel on the IEEE 1394 serial bus are managed by the IRM, the bandwidth amount is managed by the BANDWIDTH_AVAILABLE register, and the channel usage status is managed by the CHANNELS_AVAILABLE register. As shown in FIG. 6, the BANDWIDTH_AVAILABLE register (32 bits) has an area “bw_remaining” that holds a value representing the remaining bandwidth that can be used for isochronous transfer, and the CHANNELS_AVAILABLE register (64 bits) is shown in FIG. In this way, the register holds data for 64 channels in order to indicate the channel usage status. By updating this CHANNELS_AVAILABLE register and further updating the BANDWIDTH_AVAILABLE register, a channel and a band can be secured.

  Next, the IEEE 1394 interface 206 issues a lock transaction to the IRM to secure a 980-byte isochronous band and channels other than 63 channels necessary for the HD format. Further, the IEEE 1394 interface 206 increments the oPCR “pcc” by one, and at the same time, sets the oPCR “channel” to the reserved channel and transmits the HD format (step S304).

  As described above, according to the present embodiment, when digital video data having a data format that requires a larger band than the SD format is transmitted, channels other than 63 channels are used to perform point-to-point connection. Since transmission is performed, a necessary band can be secured and sufficient transmission can be performed even when digital video data of any data format is transmitted.

  In the present embodiment, the playback unit 203 can convert to the SD and HD formats. However, the playback unit 203 can also convert to the SDL and MPEG formats. Moreover, although the example of the IEEE1394 interface has been described in the above embodiment, the present invention can be similarly applied to other interfaces, for example, wireless.

  The present invention is not limited to the apparatus of the above-described embodiment, and may be applied to a system composed of a plurality of devices or an apparatus composed of a single device. A storage medium storing software program codes for realizing the functions of the above-described embodiments is supplied to a system or apparatus, and a computer (or CPU or MPU) of the system or apparatus reads and executes the program codes stored in the storage medium. Needless to say, it will be completed by doing.

  In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention. As a storage medium for supplying the program code, for example, a floppy (registered trademark) disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD-R, magnetic tape, nonvolatile memory card, ROM is used. Can do. In addition, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also the OS running on the computer based on the instruction of the program code performs the actual processing. Needless to say, a case where the function of the above-described embodiment is realized by performing part or all of the processing is also included.

  Furthermore, after the program code read from the storage medium is written to the memory provided in the function expansion board inserted in the computer or the function expansion unit connected to the computer, the program code is expanded based on the instruction of the next program code. It goes without saying that the functions of the above-described embodiments may be realized by performing some or all of the actual processing by the CPU or the like provided on the expansion board or the expansion unit.

1 is a schematic diagram illustrating a schematic configuration of a data transfer system including a data transfer apparatus according to an embodiment of the present invention. FIG. 2 is a block diagram showing an example of an internal configuration of DVCs 101 and 105 shown in FIG. 1. It is a flowchart which shows operation | movement of embodiment. It is a figure which shows the data structure of oPCR. It is a figure which shows the data structure of iPCR. It is a figure which shows the data structure of a BANDWIDTH_AVAILABLE register. It is a figure which shows the data structure of a CHANNELS_AVAILABLE register.

Explanation of symbols

101 Digital Video Camera 102 IEEE 1394 Cable 103 DTV
104 IEEE 1394 cable 105 Digital video camera 201 Digital video cassette 202 System controller 203 Playback unit 204 Video signal processing output circuit 205 Operation unit 206 IEEE 1394 interface 207 Connector

Claims (5)

In a data transfer method for transferring recorded information recorded on a recording medium,
A determining step for determining the data format of the recording information to be transferred;
A first transfer step of performing transfer using the first connection method when the data format determined by the determination step is the first data format;
When the data format discriminated in the discriminating step is a second data format that requires a larger bandwidth than that required by the first data format, transfer is performed using the second connection method. A data transfer method comprising: performing a second transfer step. The first connection method is a broadcast connection using a predetermined channel,
The data transfer method according to claim 1, wherein the second connection method is a point-to-point connection using a channel other than the predetermined channel. In a data transfer device for transferring recorded information recorded on a recording medium,
A discriminating means for discriminating a data format of recording information to be transferred;
A first transfer means for transferring using the first connection method when the data format determined by the determination means is the first data format;
When the data format discriminated by the discriminating means is the second data format that requires a band larger than the band required by the first data format, transfer is performed using the second connection method. A data transfer device comprising: a second transfer means. The first connection method is a broadcast connection using a predetermined channel,
4. The data transfer apparatus according to claim 3, wherein the second connection method is a point-to-point connection using a channel other than the predetermined channel. A computer-readable control program for executing a control method of a data transfer device for transferring recorded information recorded on a recording medium,
A determination step for determining the data format of the recording information to be transferred;
A first transfer step of performing transfer using the first connection method when the data format determined by the determining step is the first data format;
When the data format discriminated in the discriminating step is the second data format that requires a band larger than that required by the first data format, transfer is performed using the second connection method. And a second transfer step.

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