Abstract:
A receiving apparatus includes a reception unit which receives moving image data transmitted from a source node, an acquisition unit which requests the source node to send information including a vendor name of the source node so as to acquire the vendor name of the source node from the source node, and a character generation unit which generates vendor name character data indicating the vendor name of the source node acquired by the acquisition unit. A synthesis unit superimposes the vendor name character data on the moving image data if the vendor name of the source node is acquired by the acquisition unit, and superimposes predetermined character data on the moving image data if the vendor name of the source node cannot be acquired by the acquisition unit.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a receiving apparatus for receiving moving image data from a network. 
     2. Related Background Art 
     A current digital video camera is capable of receiving, through a digital interface based on IEEE Std 1394-1995, moving image data transmitted from a node on a network according to a communication protocol based on IEC61883. The moving image data received by the digital video camera are displayed on a monitor of the digital video camera and/or a display apparatus externally connected to the digital video camera, so that the user can confirm the content of such data. 
     However, the current digital video camera, in displaying the moving image data transmitted from a node on a network according to the communication protocol based on the IEC61883, is incapable of displaying a vendor name of a source node (also called transmitting apparatus) of the moving image data or a model name of such source node. Therefore, in case plural nodes are present on the network, it is not easy to specify the source node of the moving image data, displayed on the monitor of the digital video camera and/or the display apparatus externally connected to the digital video camera. Such drawback arises not only in a digital video camera but also in other apparatuses (personal computer, digital video recording, digital television receiver etc.). 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to overcome the above-described drawbacks. 
     Another object of the present invention is to facilitate specifying of the source node of moving image data received from a network. 
     A receiving apparatus includes a reception unit which receives moving image data transmitted from a source node, an acquisition unit which requests the source node to send information including a vendor name of the source node so as to acquire the vendor name of the source node from the source node, and a character generation unit which generates vendor name character data indicating the vendor name of the source node acquired by the acquisition unit. A synthesis unit superimposes the vendor name character data on the moving image data if the vendor name of the source node is acquired by the acquisition unit, and superimposes predetermined character data on the moving image data if the vendor name of the source node cannot be acquired by the acquisition unit. 
     A receiving apparatus includes a reception unit which receives moving image data transmitted from a source node, an acquisition unit which requests the source node to send information including a model name of the source node so as to acquire the model name of the source node from the source node, and a character generation unit which generates model name character data indicating the model name of the source node acquired by the acquisition unit. In addition, a synthesis unit superimposes the model name character data on the moving image data if the model name of the source node is acquired by the acquisition unit, and superimposes predetermined character data on the moving image data if the model name of the source node cannot be acquired by the acquisition unit. 
     Still other objects, features and advantages of the present invention will become fully apparent from the following detailed description of the preferred embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a view showing a network system in an embodiment; 
         FIG. 2  is a view showing a configuration of a configuration ROM provided in a source node  100  shown in  FIG. 1 ; 
         FIG. 3  is a view showing a principal configuration of a receiving apparatus  300  shown in  FIG. 1 ; 
         FIG. 4  is a flow chart showing a process sequence of the receiving apparatus  300  shown in  FIG. 1 ; and 
         FIGS. 5A ,  5 B,  5 C and  5 D are views showing examples of moving data and character data displayed on the receiving apparatus  300  and a display apparatus  400  shown in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the following there will be explained a preferred embodiment of the present invention, with reference to  FIGS. 1 to 5A  through  5 D. 
     At first an example of a network in the present embodiment will be explained with reference to  FIG. 1 . 
     A source node  100  is one of nodes present on a network  200 , and is formed by an apparatus capable of transmitting moving image data (video data) according to a communication protocol based on IEC61883, to a specified node or unspecified plural nodes on the network  200 . The source node  100  may be realized by a digital video camera, or another apparatus (personal computer, digital video recorder, digital television receiver etc.). 
     A receiving apparatus  300  is one of nodes present on the network  200 , and is capable of selectively receiving moving image data from the network  200 . The received moving image data are displayed on a monitor of the receiving apparatus  300  or a display apparatus  400  externally connected to the receiving apparatus  300 . The receiving apparatus  300  may be realized by a digital video camera, or another apparatus (personal computer, digital video recorder, digital television receiver etc.). 
     The source node  100  and the receiving apparatus  300  are connected to the network  200  through digital interfaces based on IEEE Std 1394-1995 and IEEE Std 1394a-2000. The IEEE Std 1394-1995 is one of standards relating to a serial bus, and the IEEE Std 1394a-2000 is one of extensions of the IEEE Std 1394-1995. 
     Now, reference is made to  FIG. 2  for explaining a configuration ROM provided in the source node  100 . 
     The configuration ROM in the present embodiment is based on ISO/IEC13213, IEEE Std 1394-1995, IEEE Std 1394a-2000 and Configuration ROM for AV/C Devices 1.0 (TA Document 1999027). 
     The configuration ROM  101  is provided, as shown in  FIG. 2 , with a bus information block  11 , a root directory  12 , a unit directory  13 , a vendor name textual descriptor  14 , and a model name textural descriptor  15 . 
     The bus information block  11  describes basic information defined by IEEE Std 1394-1995 and IEEE Std 1394a-2000. An EUI-64 (extended unique identifier, 64-bits), which is an ID information specific to the source node  100 , is also described in the bus information block  11 . 
     The root directory  12  includes, as shown in  FIG. 2 , entries such as a vendor ID  121 , a textual descriptor leaf offset  122 , a model ID  123 , a textual descriptor leaf offset  124 , node capabilities  125 , and a unit directory offset  126 . The vendor ID  121  describes a vendor ID for identifying the vendor of the source node  100 . The textual descriptor leaf offset  122  describes an offset value for obtaining an address of the vendor name textual descriptor  14 . The model ID  123  describes a model ID for identifying the type of the source node  100 . The textual descriptor leaf offset  124  describes an offset value for obtaining an address of the model name textural descriptor  15 . The unit directory offset  126  describes an offset value for obtaining an address of the unit directory  13 . 
     The unit directory  13  includes, as shown in  FIG. 2 , entries such as a specifier ID  131 , a version  132 , a model ID  133 , and a textual descriptor leaf offset  134 . The specifier ID  131  describes ID information (usually same as the vendor ID) specific to a unit provided in the source node  100 . The version  132  describes version information indicating a version of the unit provided in the source node  100 . The model ID  133  describes data same as those of the model ID  123 . The textual descriptor leaf offset  134  describes data same as those in the textual descriptor leaf offset  124 . 
     The vendor name textual descriptor  14  describes an ASCII code indicating the vendor name of the source node  100 . In the present embodiment, the vendor name of the source node  100  is assumed as “XXXXX”. 
     The model name textual descriptor  15  describes an ASCII code indicating the model name of the source node  100 . In the present embodiment, the model name of the source node  100  is assumed as “YYY DV20”. 
     In the following there will be explained a principal configuration of the receiving apparatus  300 , with reference to  FIG. 3 . 
     As shown in  FIG. 3 , the receiving apparatus  300  is provided with a digital interface  301 , a decoder unit  302 , a character data generation unit  303 , a superimpose unit  304 , a monitor  305 , an image output unit  306 , a control unit  307  and a memory  308 . 
     The digital interface  301  is based on IEEE Std 1394-1995 and IEEE Std 1394a-2000. The digital interface  301  has a function of selectively receiving an isochronous packet transmitted by the source node  100 , and a function of transmitting a read request packet for reading data in the configuration ROM  101  of the source node  100 . The decoder unit  302  has a function of decoding moving image data supplied from the digital interface  301 . 
     The character data generation unit  303  has a function of generating at least one of character data indicating the vendor name of the source node  100 , character data indicating the model name of the source node  100  and default character data. The superimpose unit  304  has a function of superimposing (superposing) the character data outputted from the character data generation unit  303 , on a predetermined position of the moving image data decoded by the decoder unit  302 . 
     The monitor  305  displays the moving image data supplied from the superimpose unit  304 . The image output unit  306  converts the moving image data, supplied from the superimpose unit  304 , into an image signal of a predetermined format and supplies such image signal to the display apparatus  400 . 
     The control unit  307  has a microcomputer and a memory. The memory in the control unit  307  stores a control program for controlling various functions of the DVC  100 . Also a control program for realizing a process sequence shown in  FIG. 4  is stored in the memory of the control unit  307 . The memory  308  stores data read from the configuration ROM  101  of the source node  100 . 
     Now reference is made to  FIG. 4  for explaining the process sequence of the receiving apparatus  300 . In the present embodiment, there will be explained a process sequence for receiving an isochronous packet (including moving image data) transmitted by the source node  100 . 
     Step S 401 : The digital interface  301  initiates a reception of an isochronous packet transmitted from the source node  100 . The digital interface  301  extracts moving image data from a data area of the received isochronous packet, and supplies the decoder  302  with the extracted moving image data. Receiving the moving image data, the decoder  302  decodes such moving image data. 
     Step S 402 : The digital interface  301  also extracts a CIP (common isochronous packet) header from a data area of the isochronous packet received from the network  200 , and supplies the control unit  307  with the extracted CIP header. Receiving the CIP header, the control unit  307  extracts a node ID of the source node  100  from a source ID field in the CIP header. By obtaining the node ID of the source node  100 , the receiving apparatus  300  is rendered capable of transmitting a read request packet to the source node  100 . 
     Step S 403 : The digital interface  301  generates a read request packet for reading the data in the configuration ROM  101  and transmits the generated read request packet to the source node  100 . Receiving the read request packet, the source node  100  transmits the data in the configuration ROM  101  to the receiving apparatus  300 . The data in the configuration ROM  101  are received by the digital interface  301  and are stored in the memory  308 . 
     Step S 404 : The control unit  307  refers to the memory  308  and discriminates whether the vendor name textual descriptor  14  is present in the configuration ROM  101 . If the vendor name textual descriptor  14  is present in the configuration ROM  101 , the control unit  307  executes a process of a step S 405 . On the other hand, if the vendor name textual descriptor  14  is not present in the configuration ROM  101 , the control unit  307  executes a process of a step S 408 . 
     Step S 405 : The control unit  307  refers to the memory  308  and discriminates whether the model name textual descriptor  15  is present in the configuration ROM  101 . If the model name textual descriptor  15  is present in the configuration ROM  101 , the control unit  307  executes a process of a step S 406 . On the other hand, if the model name textual descriptor  15  is not present in the configuration ROM  101 , the control unit  307  executes a process of a step S 407 . 
     Step S 406 : The control unit  307  extracts (fetch) an ASCII code (this ASCII code representing a vendor name of the source node  100 ) from the vendor name textual descriptor  14 , and sends the extracted ASCII code to the character data generation unit  303 . Also the control unit  307  extracts an ASCII code (this ASCII code representing a model name of the source node  100 ) from the model name textual descriptor  15 , and sends the extracted ASCII code to the character data generation unit  303 . The character data generation unit  303  generates character data indicating the vendor name of the source node  100  utilizing the ASCII code extracted from the vendor name textual descriptor  14 , and also generates character data indicating the model name of the source node  100  utilizing the ASCII code extracted from the model name textual descriptor  15 . These two character data are generated instead of the default character data. The superimpose unit  304  superimposes the two character data, generated in the character data generation unit  303 , on a predetermined position of the moving image data decoded in the decoder unit  302 . The moving image data, in which the character data indicating the vendor name and the model name of the source node  100  is superimposed, are supplied to the monitor  305  and the image output unit  306 , and displayed on the monitor  305  and the display apparatus  400 . An example of the moving image data and the character data, displayed on the monitor  305  and the display apparatus  400  is shown in  FIG. 5A . In  FIG. 5B , “XXXXX” indicates character data indicating the vendor name of the source node  100 , and, in  FIG. 5A , “YYY DV20” indicates character data indicating the model name of the source node  100 . 
     Step S 407 : The control unit  307  extracts an ASCII code (this ASCII code representing a vendor name of the source node  100 ) from the vendor name textual descriptor  14 , and sends the extracted ASCII code to the character data generation unit  303 . The character data generation unit  303  generates character data indicating the vendor name of the source node  100  utilizing the ASCII code extracted from the vendor name textual descriptor  14 . The character data are generated instead of the default character data. The superimpose unit  304  superimposes the character data, generated in the character data generation unit  303 , on a predetermined position of the moving image data decoded in the decoder unit  302 . The moving image data, in which the character data indicating the vendor name of the source node  100  is superimposed, are supplied to the monitor  305  and the image output unit  306 , and displayed on the monitor  305  and the display apparatus  400 . An example of the moving image data and the character data, displayed on the monitor  305  and the display apparatus  400  is shown in  FIG. 5B . In  FIG. 5B , “XXXXX” indicates character data indicating the vendor name of the source node  100 . 
     Step S 408 : The control unit  307  refers to the memory  308  and discriminates whether the model name textual descriptor  15  is present in the configuration ROM  101 . If the model name textual descriptor  15  is present in the configuration ROM  101 , the control unit  307  executes a process of a step S 409 . On the other hand, if the model name textual descriptor  15  is not present in the configuration ROM  101 , the control unit  307  executes a process of a step S 410 . 
     Step S 409 : The control unit  307  extracts an ASCII code (this ASCII code representing a model name of the source node  100 ) from the model name textual descriptor  15 , and sends the extracted ASCII code to the character data generation unit  303 . The character data generation unit  303  generates character data indicating the model name of the source node  100  utilizing the ASCII code extracted from the model name textual descriptor  15 . The character data are generated instead of the default character data. The superimpose unit  304  superimposes the character data, generated in the character data generation unit  303 , on a predetermined position of the moving image data decoded in the decoder unit  302 . The moving image data, in which the character data indicating the model name of the source node  100  is superimposed, are supplied to the monitor  305  and the image output unit  306 , and displayed on the monitor  305  and the display apparatus  400 . An example of the moving image data and the character data, displayed on the monitor  305  and the display apparatus  400  is shown in  FIG. 5C . In  FIG. 5C , “YYY DV20” indicates character data indicating the model name of the source node  100 . 
     Step S 410 : The control unit  307  informs the character data generation unit  303  of generation of default character data. In response, the character data generation unit  303  generates default character data. The superimpose unit  304  superimposes the default character data, generated in the character data generation unit  303 , on the moving image data decoded in the decoder unit  302 . The moving image data, in which the default character data are superimposed, are supplied to the monitor  305  and the image output unit  306  and displayed on the monitor  305  and the display apparatus  400 . An example of the moving image data and the character data displayed on the monitor  305  and the display apparatus  400  is shown in  FIG. 5D , in which “DV IN” is the default character data. 
     Step S 411 : The control unit  307  discriminates whether the digital interface  301  has detected generation of a bus reset. If the digital interface  301  detects generation of a bus reset, the control unit  307  executes a process of a step S 413 . 
     Step S 412 : The control unit  307  discriminates whether the reception of the moving image data is to be terminated. If the reception of the moving image data is to be terminated, the control unit  307  executes a process of a step S 413 . 
     Step S 413 : The control unit  307  informs the character data generation unit  303  of an end of display of the character data. In response, the character data generation unit  303  terminates generation of the character data. As a result, the monitor  305  and the display apparatus  400  no longer display the default characters, the characters indicating the vendor name or the characters indicating the model name. 
     As explained in the foregoing, the receiving apparatus  300  of the present embodiment, in displaying the moving image data received from the network  200 , can display the vendor name and/or the model name of the source node of the moving image data, thereby facilitating to identify the source node of the moving image data. 
     The above-described preferred embodiments are merely exemplary of the present invention, and are not to be construed to limit the scope of the present invention. 
     The scope of the present invention is defined by the scope of the appended claims, and is not limited to only the specific descriptions in this specification. Furthermore, all modifications and changes belonging to equivalents of the claims are considered to fall within the scope of the present invention.