JP2004274781A - Data-receiving terminal and data-receiving method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a data-receiving terminal which can initiate data reception/replay from the time at which a connection to a server is disconnected in a streaming replay with RTP/UDP/IP (Real-time Transpot Protocol/User Datagram Protocol/Internet Protocol). <P>SOLUTION: In the data-receiving terminal 12, during receiving/replaying particular contents, a time-stamp for data with completed replay are stored in a memory 105. When reconnection to the particular content is carried out, data transmission from the time-stamp stored in the memory 105 is requested to a transmission device (server) 11 . <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to a data receiving terminal for receiving and reproducing AV data transmitted from a server in order to realize reproduction of AV (audio / video) data adaptable to changes in usable bandwidth, transmission errors, failures, and the like. And a data receiving method.

  In recent years, with the development of video encoding technology such as MPEG (Moving Picture Experts Group) -4, AV distribution services for mobile wireless terminals such as mobile phones have been started, and such AV distribution services will be widely spread in the future. It is thought to go.

  At present, there are mainly two types of data transmission systems for AV distribution, such as download / reproduction by HTTP / TCP / IP (Hyper Text Transfer Protocol / Transmission Control Protocol / Internet Protocol) and RTP / UDP / There is streaming reproduction by IP (Realtime Transport Protocol / User Datagram Protocol / Internet Protocol). In a control system for streaming reproduction, for example, a protocol called RTSP (Real Time Streaming Protocol) is used (H. Schulzrinne et al., "Real Time Streaming Protocol", RFC 2326, Internet Engineering Taskforce, Apr. 1998).

  Since the download reproduction by HTTP / TCP / IP uses the same data transmission protocol as when browsing the Internet homepage, it is easy to realize. On the other hand, if a transmission error occurs, the data is retransmitted. It is not very suitable for real-time reproduction of AV data that requires real-time performance. On the other hand, in streaming reproduction by RTP / UDP / IP, data is not retransmitted even in the case of a transmission error, so there is no guarantee that data is transmitted reliably. Suitable for reproduction.

  Also, in download reproduction by HTTP / TCP / IP, normally received data is stored in the memory of the terminal even after reproduction, so that it is not possible to distribute content for a long time due to memory restrictions. On the other hand, in streaming reproduction by RTP / UDP / IP, normally received data is discarded after reproduction, so that there is little time restriction on content to be distributed, and reception and reproduction of content can be performed for a long time.

  In the conventional streaming reproduction by RTP / UDP / IP, when the transmission path is disconnected, the power of the terminal is unexpectedly turned off, or the reproduction is interrupted by interruption of another application, etc., the AV data is restored after restoration. It was not easy to resume playing. Specifically, if the connection with the server is disconnected during the data reproduction of a certain content, the time at which the connection was disconnected cannot be specified. It was necessary to receive and reproduce the data from the beginning. For this reason, it is not possible to view specific content at several times by changing the time and place for the convenience of the user, which is inconvenient especially when viewing the content for a long time. Was.

  A mobile wireless terminal such as a mobile phone has a feature that a user can use the mobile terminal while moving, but if the user moves to an area where radio waves do not reach (a non-receivable area) such as a tunnel, the mobile wireless terminal may take a long time. Data may not be received. In such a case, in streaming reproduction by RTP / UDP / IP, data transmitted while in the non-receivable area is not retransmitted, so that data in the non-receivable area is completely lost, and However, there is a problem that data cannot be watched during a long time.

  The present invention has been made in view of the above problems, and has as its object to provide a data receiving terminal and a data receiving method capable of resuming reproduction from a middle of a data stream in streaming reproduction.

  In order to solve the above-mentioned problem, in the present invention, time information at the time when reproduction of the data stream is interrupted is held, and reproduction is restarted from the middle of the data stream based on the time information.

  According to the present invention, the current reproduction time is held at the data receiving terminal or the transmitting terminal (server), and when the reception buffer of the data receiving terminal becomes empty, when the transmission path is disconnected due to a failure, etc. When the power of the terminal is turned off, when an interrupt is generated from another application (for example, an Internet phone), the AV reproduction is temporarily stopped. When the transmission path is restarted, when the power of the terminal is turned on again, or when the interrupt from another application is released, the time when the reception buffer becomes empty and the time when the transmission path is disconnected Automatically starts data buffering from the playback time when the power of the terminal is turned off or when an interrupt from another application occurs, and reproduces the data, thereby realizing AV transmission resistant to failure. It becomes possible. Specifically, the reproduction time t1 is stored in the data receiving terminal (an application name, a reproduction content name, a user name, and the like are also stored as necessary), and even if the transmission path is temporarily disconnected, the transmission path is restarted. In this case, a request is issued from the data receiving terminal to the transmitting terminal (server) so as to be reproduced from the reproduction time t1.

  For example, in the data receiving terminal, the time stamp of the reproduced data is stored, and even if the connection with the server is disconnected due to the user's convenience or the reception condition is deteriorated, the reproduction is performed by the previous connection. It is possible to play back the continued data.

  As described above, according to the present invention, the time information at the time when the reproduction of the data stream is interrupted in the streaming reproduction is retained, so that the reproduction is restarted from the middle of the data stream based on the time information. can do. For example, when the transmission path is cut off, the power of the terminal is unexpectedly turned off, or an application interrupt occurs, the reproduction of the AV data can be automatically restarted after the connection is restored.

  Hereinafter, a data receiving terminal according to an embodiment of the present invention will be described with reference to the drawings.

(1st Embodiment)
FIG. 1 is a block diagram showing an example of the configuration of the data receiving terminal according to the first embodiment of the present invention. In FIG. 1, a data receiving terminal 12 according to the present invention receives and reproduces an RTP packet transmitted from a transmitting device (server) 11 by a transmission method based on RTP / UDP / IP. Comprises a data receiving unit 101, a receiving buffer 102, a decoding unit 103, a display unit 104, a memory 105, a control unit 106, a user input unit 110, and a message transmitting / receiving unit 111. The control unit 106 includes a connection destination address detection unit 107, a memory management unit 108, and a connection request creation unit 109.

  FIG. 2 is a diagram for explaining an RTP packet transmitted from the transmission device 11 by a transmission method based on RTP / UDP / IP. As shown in FIG. 2, the RTP packet includes a header part and a data part. The header section includes time information such as a reproduction time. An MPEG4 video stream is stored in the data section. For example, one frame of the video stream is stored in the data section of the RTP packet. In MPEG-4, this unit (one frame) is called a VOP (Video Object Plane). Here, description will be made assuming that one VOP data is transmitted for each RTP packet.

  FIG. 3 is a diagram illustrating an example of a memory structure of the reception buffer 102. The data receiving unit 101 receives the RTP packet transmitted from the server, calculates the VOP size, and stores, together with the calculated VOP size, a time stamp indicating the reproduction order of the received VOP data, and the VOP data into a reception buffer 102. To be stored. As shown in FIG. 3, the reception buffer 102 stores a time stamp 201, a VOP size 202, and VOP data 203 so as to form a set. The decoding unit 103 decodes each VOP data stored in the reception buffer 102 according to the time stamp attached thereto, outputs the decoded data to the display unit 104, and outputs the decoded data to an I-VOP (intra-coded VOP). If it is, the time stamp corresponding to the I-VOP is output to the memory management unit 108. The display unit 104 displays the input data on a display screen.

  FIG. 4 is a diagram showing an example of the contents stored in the memory 105. As shown in FIG. 4, the memory 105 is indicated by an active flag indicating the content being received, a reproduction completion flag indicating the content that has been reproduced to the end, a connection destination address indicating the connection destination address, and a connection destination address. A plurality of entries each storing a set of a time stamp indicating the position where the reproduction of the content has ended and an access date and time indicating the date and time when the access was performed are stored. In the present embodiment, the active flag sets the content being received to 1 and the others to 0. The reproduction completion flag is set to 1 for content whose reproduction has been completed to the end, and set to 0 for other contents.

  The control unit 106 controls the entire data receiving terminal 12, manages the memory 105, and issues a connection request to the server. More specifically, the connection destination address detection unit 107 detects whether or not the entry of the connection destination address output from the user input unit 110 is registered in the memory 105 and registers the entry of the connection destination address. If the connection request creation unit 109 requests to detect the time stamp of the entry, the time stamp of the entry is detected. The memory management unit 108 manages the memory 105, and generates a new entry and outputs a time stamp from the decoding unit 103, thereby setting a time stamp for the currently receiving connection destination in the memory 105. Replace with the time stamp output from the decoding unit 103. The connection request creation unit 109 creates a connection request to the server based on the user's instruction input to the user input unit 110 and the information stored in the memory 105.

  The user input unit 110 is, for example, an operation button or a touch panel. The user input unit 110 analyzes an external input such as a user's selection or depression, and outputs an analysis result to the control unit 106. The message transmission / reception unit 111 transmits the connection request created by the connection request creation unit 109 to the server and processes a response from the server.

  Next, the operation of the data receiving terminal 12 of the present invention will be specifically described. For example, the user inputs a connection destination address of desired content to the user input unit 110, or sets an area where a link to video data or the like is established from a scene of the content displayed by the display unit 104. By making the selection, the connection destination address is output from the user input unit 110 to the connection destination address detection unit 107. When the connection destination address is output from the user input unit 110, the connection destination address detection unit 107 searches the memory 105 to determine whether an entry of the connection destination address output from the user input unit 110 is registered, The detection result is output to the memory management unit 108 and the connection request creation unit 109.

  FIG. 5 is a flowchart illustrating an example of the operation of the memory management unit 108 receiving the detection result from the connection destination address detection unit 107. The memory management unit 108 receives the detection result from the connection destination address detection unit 107, The operation described below is performed. First, the memory management unit 108 receives the detection result from the connection destination address detection unit 107 in step S101. If the entry of the connection destination address is registered, the process proceeds to step S102, and the entry of the connection destination address is registered. If not, go to step S103. When the entry of the connection destination address is registered, the memory management unit 108 sets the active flag of the entry registered in the memory 105 to “1” (Step S102). On the other hand, if the connection destination address is not registered, the memory management unit 108 searches for an empty area in the memory 105 in step S103. If there is an empty area in the memory, the memory management unit 108 proceeds to step S104. If there is no free area, the process proceeds to step S105. If there is a free area in the memory, a new entry is created in the free area (step S104). The creation of a new entry by the memory management unit 108 is performed by setting the connection destination address designated by the user input unit 110 to the connection destination address, further setting the active flag to "1", and setting the reproduction completion flag to "0". , By setting the time stamp to “0”. On the other hand, if there is no free space in the memory, the memory management unit 108 searches in step S105 for an entry whose reproduction completion flag of the entry stored in the memory 105 is “1”. If there is an entry whose reproduction completion flag is "1", the flow proceeds to step S106, and if there is no entry whose reproduction completion flag is "1", the flow proceeds to step S107. If there is an entry whose reproduction completion flag is "1", a new entry is created by overwriting the entry whose reproduction completion flag is "1" (step S106). When there are a plurality of entries whose reproduction completion flag is “1”, the entry having the oldest access date and time is selected from those entries, and a new entry is overwritten on the selected entry. On the other hand, if there is no entry whose reproduction completion flag is "1", the entry with the oldest access date and time is selected from the registered entries, and a new entry is overwritten and created on the selected entry (step S107). ).

  FIG. 6 is a flowchart illustrating an example of the operation of the connection request creation unit 109 that has received the detection result from the connection destination address detection unit 107. The connection request creation unit 109 converts the detection result from the connection destination address detection unit 107. In response, the operation described below is performed. First, the connection request creation unit 109 receives the detection result from the connection destination address detection unit 107 in step S201, and if an entry of the connection destination address is registered, the process proceeds to step S202, where the entry of the connection destination address is registered. If not, the process proceeds to step S205. If the entry of the connection destination address is registered, the connection request creation unit 109 refers to the reproduction completion flag of the entry and detects whether the reproduction completion flag is “0” (step S202). . When the reproduction completion flag is “0”, the process proceeds to step S203, and when the reproduction completion flag is not “0”, the process proceeds to step S205. If the reproduction completion flag is “0”, the previous reproduction has been completed halfway, so the connection request creation unit 109 requests the display unit 104 to determine whether or not to receive from the previous continuation. A signal to display the message is output to the display unit 104 and displayed (step S203). When a selection signal for selecting to receive data from the previous continuation is output from the user input unit 110, the connection request creation unit 109 sends the entry request via the connection destination address detection unit 107. In order to request the reception of data from the previous continuation of the content indicated by the connection destination address, a connection request indicating the reception start position indicated by the time stamp is created. Output (Step S204). On the other hand, when a selection signal for selecting not to receive data from the previous continuation is output from the user input unit 110, and when an entry of the connection destination address is not registered, If the reproduction completion flag of the entry is not “0”, the connection request creation unit 109 creates a connection request that does not indicate a reception start position to receive data from the beginning of the content indicated by the connection destination address, Output to the message transmitting / receiving unit 111 (step S205).

  The message transmission / reception unit 111 that has received the connection request from the connection request creation unit 109 transmits the connection request created by the connection request creation unit 109 to the server as an RTSP SETUP message. Then, upon receiving an OK response from the server, it transmits a PLAY message to the server. Further, upon receiving an OK response from the server in response to the PLAY message, the message transmission / reception unit 111 releases the data reception unit 101 to enable data reception. On the other hand, if the message transmission / reception unit 111 cannot receive an OK response from the server, the message transmission / reception unit 111 determines that connection is not possible, and notifies the user by displaying the fact that connection is not possible via the display unit 104. The data receiving unit 101 released by the message transmitting / receiving unit 111 receives the RTP packet data sequence transmitted from the server, and stores the time stamp, data size, and VOP data for each VOP in the receiving buffer 102.

  The decoding unit 103 sequentially reads and decodes data from the reception buffer 102 according to the time stamp of each VOP stored in the reception buffer 102, and outputs the decoded data to the display unit 104. At the same time, the decoding unit 103 determines whether or not the data being decoded is an I-VOP at the time of decoding the data. If the decoded data is an I-VOP, the decoding unit 103 The time stamp to be output is output to the memory management unit 108. On the other hand, if the decoded data is not an I-VOP, the time stamp corresponding to the I-VOP is not output to the memory management unit 108. Upon receiving the output of the time stamp from the decoding unit 103, the memory management unit 108 detects an entry in which the active flag indicating the connection destination address currently being received is “1” from the memory 105, and decodes the time stamp of the entry into the decoding unit. Replace with the time stamp output from 103. The data decoded by the decoding unit 103 is displayed by the display unit 104 and provided to the user.

  When the reproduction of the content being received is completed to the end, a signal indicating that the reproduction of the content has been completed is output from the decoding unit 103 to the memory management unit 108, and the memory management unit 108 sets the active flag in the memory 105 to “1”. Is detected, the reproduction completion flag of the entry is set to “1”, and the active flag is reset to “0”.

  Next, the operation of the data receiving terminal 12 when the user performs an operation for disconnecting the connection with the server to the user input unit 110 during data reproduction will be described. For example, when a button for interrupting data reception / reproduction is pressed on the user input unit 110, a signal indicating that data reception / reproduction is interrupted is output from the user input unit 110 to the control unit 106. You. The control unit 106, which has received a signal from the user input unit 110 to suspend data transmission / reception, performs a process of stopping data reception / reproduction. That is, the control unit 106 closes the data receiving unit 101, resets the receiving buffer 102 and the decoding unit 103, and resets all the active flags of the entries in the memory 105 to “0”. At this time, the memory management unit 108 records the time stamp of the I-VOP decoded and reproduced at the end of the data previously reproduced in the memory 105. Further, the control unit 106 instructs the message transmitting / receiving unit 111 to stop transmitting data, and the message transmitting / receiving unit 111 transmits an RTSP TEARDOWN message to the server. As a result, transmission from the server stops.

  As described above, in the data receiving terminal 12 according to the present embodiment, the memory management unit 108 stores in the memory 105 the time stamp of the last decoded / reproduced data at the time of data reproduction, so that the user ends the reception halfway. Even when the content is reproduced, it is possible to receive data from the continuation of the previous reproduction when the content is reproduced again. Can be viewed separately.

  In addition, among the entries stored in the memory 105, the entry indicating the currently connected content is represented using the active flag, so that the memory management unit 108 checks the active flag when updating the time stamp. As a result, an entry for updating the time stamp can be detected, so that the time stamp update processing speed can be improved and power consumption can be reduced. Further, among the entries stored in the memory 105, the entry indicating the content that has been reproduced to the end is represented using the reproduction completion flag, so that the connection request creation unit 109 Thus, the entry whose reproduction has been completed to the end can be detected, so that the speed of creating the connection request can be improved and the power consumption can be reduced.

  Further, when the decoding unit 103 decodes the intra-coded data (I-VOP), the time stamp of the data is output to the memory management unit 108. Can be reduced, power consumption can be reduced, and when data is received from the continuation of the previous reproduction, reception can be restarted from intra-coded data.

  Note that the connection request creation unit 109 of the data receiving terminal 12 according to the present embodiment displays a message as to whether or not to perform reproduction from the previous continuation and allows the user to determine whether or not to perform reproduction from the middle. However, for example, when the entry of the connection destination address is registered and the reproduction completion flag is “0”, the connection request is automatically made to receive the data of the content from the previous continuation. It may be created.

(Second embodiment)
FIG. 7 is a block diagram illustrating an example of a configuration of a data receiving terminal according to the second embodiment of the present invention. In FIG. 7, a data receiving terminal 22 according to the present invention receives and reproduces an RTP packet transmitted from a transmitting device (server) 21 by a transmission method based on RTP / UDP / IP. The transmission device 21 includes a reception status analysis unit 201. Further, the data receiving terminal 22 includes a data receiving unit 101, a receiving buffer 102, a decoding unit 103, a display unit 104, a memory 105, a control unit 106, a user input unit 110, a message transmitting / receiving unit 111, And a reception status notification unit 202. The control unit 106 includes a connection destination address detection unit 107, a memory management unit 108, and a connection request creation unit 109.

  The data reception terminal 22 according to the second embodiment is different from the data reception terminal 12 described in the first embodiment in that a reception status notification unit 202 for notifying the connection status with the transmission device 21 is further provided. This is different from the data receiving terminal 12 according to the embodiment. The same components as those of the data receiving terminal 12 according to the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

  The reception status notification unit 202 of the data reception terminal 22 operates during connection with the transmission device 21, and transmits a reception report indicating that data has been received to the reception status analysis unit 201 of the transmission device 21. , The transmission device 21 always receives the transmission report indicating that the data has been transmitted, and if the transmission report transmitted from the transmission device 21 is not received for a predetermined time, the data receiving terminal 22 It is determined that it has entered an area where radio waves cannot reach (an unreceivable area), such as a tunnel, and that fact is output to the control unit 106. In response, the control unit 106 closes the data receiving unit 101, resets the receiving buffer 102 and the decoding unit 103, resets all the active flags of the entries in the memory 105 to "0", and sets the display unit 104 A message indicating that the connection has been disconnected is displayed via. At this time, the memory management unit 108 records the time stamp of the I-VOP decoded and reproduced at the end of the data previously reproduced in the memory 105.

  On the other hand, similarly, the reception status analysis unit 201 of the transmission device 21 operates during the connection with the data reception terminal 22, receives the reception report transmitted from the reception status notification unit 202 of the data reception terminal 22, and transmits the reception report. When the report is constantly transmitted and the reception report transmitted from the data reception terminal 22 is not received for a predetermined period of time, the data reception terminal 22 may be in an area where radio waves such as a tunnel cannot reach (reception is impossible). Area), the session is disconnected, that is, the transmission of RTP data from the transmission device 21 is stopped.

  As described above, the transmitting device (server) 21 and the data receiving terminal 22 according to the present embodiment exchange communication reports between the transmitting device 21 and the data receiving terminal 22 as to whether the connection is always maintained. Since it is possible to mutually detect that the data receiving terminal 22 has entered an unreceivable area such as a tunnel and to cut off the subsequent session, it is possible to reduce communication costs without transmitting useless data. The bandwidth can be used effectively. Also, since the time stamp of the last displayed I-VOP is recorded in the memory 105, playback can be resumed from the point where the connection was disconnected, and the disconnected content can be re-started from the beginning. There is no need to review the content, and the content can be viewed efficiently.

  In the present embodiment, when the reception status notification unit 202 does not receive the transmission report transmitted from the transmission device 21 for a predetermined time, it determines that the data reception terminal 22 has entered the non-reception area. However, for example, the reception status notification unit 202 monitors the reception status of the RTP packet of the data reception unit 101, and when the data reception unit 101 has not received the RTP packet for a certain period, the data reception terminal 22 May be determined to have entered the unreceivable area.

  Also, when the reception status analysis unit 201 of the transmitting device 21 determines that the data receiving terminal 22 has entered the unreceivable area, the transmitting device 21 records the time stamp of the I-VOP at that time. Is also good. Even in such a case, the reproduction can be resumed from the point where the connection is disconnected. However, since the data reception terminal 22 has not been able to estimate up to which point of data the data has actually been received, the present embodiment is superior in terms of certainty.

  Now, in the data receiving terminals 12 and 22 according to the above embodiments, the description has been given of the case where the decoding unit 103 updates the time stamp of the content being received stored in the memory 105 when the I-VOP data is decoded. However, regardless of the type of data, the decryption unit 103 updates the time stamp of the content being received stored in the memory 105 every time the data is decrypted, or updates the time stamp every time a predetermined time elapses. Or the like. Further, not only a time stamp that affects the decoding order, that is, a DTS (Decoding Time Stamp), but also a so-called CTS (Composition Time Stamp) or a PTS (Presentation Time Stamp) may be used.

FIG. 2 is a block diagram illustrating an example of a configuration of a data receiving terminal according to the first embodiment of the present invention. FIG. 2 is a diagram for explaining an RTP packet transmitted from the transmission device in FIG. 1 by a transmission method based on RTP / UDP / IP. FIG. 2 is a diagram illustrating an example of a memory structure of a reception buffer in FIG. 1. FIG. 2 is a diagram illustrating an example of storage contents of a memory in FIG. 1. 4 is a flowchart illustrating an example of an operation of the memory management unit in FIG. 3 is a flowchart illustrating an example of an operation of a connection request creation unit in FIG. 1. It is a block diagram showing an example of the composition of the data receiving terminal by a 2nd embodiment of the present invention.

Explanation of reference numerals

11, 21 Transmitting device 12, 22 Data receiving terminal 101 Data receiving unit 102 Reception buffer 103 Decoding unit 104 Display unit 105 Memory 106 Control unit 107 Connection destination address detection unit 108 Memory management unit 109 Connection request creation unit 110 User input unit 111 Message Transmission / reception unit 201 Reception status analysis unit 202 Reception status notification unit

Claims (14)

A data receiving terminal for receiving and reproducing data transmitted from the server,
Data receiving means for receiving data having a time stamp indicating a reproduction order;
A decoding unit for decoding the data received by the data receiving unit in the order of the time stamp, and outputting a time stamp of the decoded data,
Display means for displaying the data decoded by the decoding means,
At least a memory for storing a connection destination address and a time stamp as a set,
Memory management means for managing the time stamp output from the decoding means so as to replace the time stamp corresponding to the connected destination address in the memory,
A user input means for analyzing an operation from outside and outputting at least a connection destination address;
Connection destination address detection means for detecting whether the connection destination address output from the user input means is stored in the memory,
Sending data to the server based on the connection destination address output from the user input means, the detection result of the connection destination address detection means, and the connection destination address and time stamp stored in the memory; Connection request creation means for creating a connection request requesting
A data reception terminal, comprising: a message transmission / reception unit for transmitting a connection request created by the connection request creation unit to the server and processing a response from the server. The data receiving terminal according to claim 1,
The connection request creation unit, when the connection destination address detection unit detects the connection destination address indicated by the user input unit from the memory, the data indicated by the time stamp for the connection destination address A data receiving terminal for requesting data transmission from a position. The data receiving terminal according to claim 1,
The user input unit further analyzes an operation from outside and outputs a selection signal for the message,
The connection request creating unit, when the connection destination address detection unit detects the connection destination address indicated by the user input unit from the memory, a time stamp for the connection destination address via the display unit. Displaying a message asking whether to request transmission of data from the server, and creating a connection request to the server based on a selection signal for the message output from the user input means. Data receiving terminal. The data receiving terminal according to claim 1,
The memory at least stores an active flag indicating whether or not the content is being received, the connection destination address, and the time stamp as a set,
The memory management unit, when a time stamp is output from the decoding unit, detects an active flag indicating that reception is in progress from the active flag stored in the memory, and a time stamp corresponding to the active flag indicating that reception is in progress. A data receiving terminal characterized by being replaced. The data receiving terminal according to claim 1,
The memory stores at least a playback completion flag indicating the content that has been played to the end, the connection destination address, and the time stamp, as a set. The connection request creation unit stores the user input in the memory. When the reproduction completion flag for the connection destination address output from the means indicates that the reproduction has been completed, a connection request for requesting data transmission from the beginning of the connection destination address is created. Data receiving terminal. The data receiving terminal according to claim 1,
The data receiving terminal, wherein the decoding means outputs a time stamp of the intra-coded data to the memory management means every time the data is decoded. The data receiving terminal according to claim 1,
A reception status notifying unit that operates during connection with the server and transmits a reception report indicating that data has been received, and always receives a transmission report indicating that data has been transmitted, transmitted from the server. Prepare,
The reception status notifying unit outputs a signal indicating that the user has entered an area where data cannot be received when the transmission report transmitted from the server is not received for a predetermined time. Data receiving terminal. The data receiving terminal according to claim 1,
Monitoring the data reception status of the data reception means, and further comprising a reception status notifying means for outputting a signal indicating that the data reception area has entered an area where data cannot be received if the data reception is not received for a predetermined period. A data receiving terminal comprising: A data receiving method for receiving and reproducing data transmitted from a server,
A data receiving step of receiving data having a time stamp indicating a reproduction order;
Decoding the received data in the order of the time stamps, and outputting a time stamp of the decoded data;
A display step of displaying the data decoded by the decoding step;
A memory management step of storing the time stamp output from the decoding step, at least, in a memory in combination with a connection destination address being connected;
An external input / output step of analyzing an external operation and outputting at least a connection destination address;
A connection destination address detection step of detecting whether the connection destination address output from the external input output step is stored in the memory,
Data transmission to the server based on the connection destination address output from the external input output step, the detection result of the connection destination address detection step, and the connection destination address and the time stamp stored in the memory. A connection request creation step for creating a requested connection request;
Transmitting a connection request created in the connection request creation step to the server and processing a response from the server. The data receiving method according to claim 9,
In the connection destination address detecting step, when it is detected that the connection destination address is not stored in the memory, it is detected whether or not there is a free area in the memory. Is registered in the memory. The data receiving method according to claim 10,
If there is no free space in the memory, it is detected whether or not there is data that has already been reproduced in the display step, and if there is data that has been reproduced, a new connection is made to the data that has been reproduced. A data receiving method characterized by overwriting and registering a destination address. The data receiving method according to claim 11,
A data receiving method characterized in that when there are a plurality of data whose reproduction has been completed, the data is overwritten and registered in the order of access time from the time of registration. The data receiving method according to claim 10,
If there is no free space in the memory, it is detected whether or not there is data that has already been played back in the display step. If there is no data that has been played back, the access time starts from the registration of the connection destination address. Is a method of overwriting and registering already registered data with a new connection destination address in an old order. The data receiving method according to claim 9,
Operating during the connection with the server, transmission of a reception report indicating that data has been received, and transmitted from the server, a reception status notification step of always receiving a transmission report indicating that the data has been transmitted,
Outputting a signal indicating that the user has entered an area where data cannot be received if the transmission report transmitted from the server is not received for a predetermined period of time. Data receiving method.

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