JP2007110395A - STREAM DATA TRANSFER DEVICE, STREAM DATA TRANSFER METHOD, PROGRAM USED FOR THEM, AND RECORDING MEDIUM - Google Patents

Abstract

The present invention enables viewing and the like on-time while transferring stream data.
Stream data transmission management means 0106 and stream data reception management means 0206 manage stream data transmission / reception. It is checked whether the stream data packet sent is correctly received or high-quality stream data. If not, the packet is stored. Packets that have not been received or are not of high quality are retransmitted with reliable stream data transfer. Transmission stream data management means 0102 and reception stream data management means 0202 manage stream data. For example, when the storage period of the stream data stored in the stream data receiving system has passed, the stream data is deleted.
[Selection] Figure 1

Description

  The present invention relates to a stream data transfer technique, and more particularly, to a technique for transferring stream data on time using an unstable communication path and recording high-quality stream data on the receiving side.

  In recent years, digitalization of broadcasting has progressed, and more content has been broadcast on more channels. CATV systems are also being digitized, and multi-channels are being developed.

  In such a multi-channel broadcasting system, video on demand (hereinafter referred to as “VOD”) and pseudo video on demand (hereinafter referred to as “NVOD”) services are being started as new services. VOD allows viewers to enjoy the content they want on demand at the time they want, but because it is necessary to allocate content and broadcast the content for the convenience of the viewer, the number of channels is reduced due to the digitization of broadcasting. Although it has increased, it is basically impossible to meet the demands of all viewers.

  In order to cope with this problem, NVOD has been developed that repeatedly broadcasts one content using a plurality of channels according to a certain time shift. By using the NVOD system, the viewer can watch the desired content by waiting for a predetermined time (for example, a maximum of 15 minutes) at the maximum.

  Usually, the digitized stream data is compressed and broadcast. For example, in CS / BS digital broadcasting and terrestrial digital broadcasting, video is digitized and compressed by MPEG2 (ISO / IEC 13818-2 (ITU-T H.262)) and broadcast. The rate (referred to herein as “reproduction rate”) is approximately 6 Mpbs for normal broadcasting (SD, Standard Definition). Also, the transfer rate (herein referred to as “transfer rate”) when broadcasting is the same as the playback rate. This is because, if the reproduction rate and the transfer rate are different, the stream data sent on the receiver side must be recorded and reproduced by the recording device. The capacity for recording varies depending on the length of the content, the value of the reproduction rate, and the ratio between the reproduction rate and the transfer rate. Recently, H.264 / AVC (ISO / IEC 14496-10 MPEG-4 Part 10 (ITU-T H.264)) with higher compression efficiency has been used. H.264 / AVC is used in broadcasting for terminals (commonly called “1 segment broadcasting”).

  In recent years, Internet broadbandization has progressed, and streaming contents have been downloaded and viewed, and live images and the like known as Internet broadcast technology are being viewed simultaneously while being transferred on-time. VOD and NVOD services have also been started using the Internet. This is largely due to the increase in subscribers to ADSL and FTTH and the enhancement of the backbone network.

  In order to transfer these stream data using the Internet, it is necessary to transfer the data in real time. Therefore, UDP (User Datagram Protocol) is used without using TCP (Transmission Control Protocol). This is because, when data is transferred using TCP, if packets are lost on the communication path or if the order of packets reaching the receiving side is changed, reliability is ensured by advanced protocol processing such as packet retransmission. This is because it is not suitable for real-time data transfer. For this reason, UCP, which has low reliability but does not perform advanced protocol processing and can ensure real-time performance, uses RTP (Real-time Transport Protocol) as its application protocol. Also, RTCP (RTP Control Protocol) is used as a control protocol when transmitting stream data using RTP.

  On the other hand, using HTTP (Hypertext Transfer Protocol) as an application protocol on TCP, not only transferring HTML (Hypertext Markup Language) documents, but also the bandwidth of the communication path is sufficiently large, delay, delay fluctuation (jitter), When QOS (Quality Of Service) such as packet discard and bandwidth fluctuation is guaranteed to some extent and is sufficiently reliable, stream data such as video and audio may be transferred in real time. In addition, when real-time performance is not required even if the reliability of the communication path is not sufficient, stream data may be transferred using HTTP.

  Generally, streaming systems are classified into a download type, a pseudo streaming type, and a streaming type. In the download type, stream data is downloaded in advance and stored in a storage device on the receiving side, and when the download is completed, the reproduction of the content is started. In the download type, the stream data transfer rate and the playback rate may be different. Strictly speaking, the download type is not a streaming system. In the pseudo streaming type, a large buffer is prepared on the receiving side, and reproduction is started when stream data is accumulated in the buffer to some extent. Here, the buffer for storing the stream data for a short time must not be empty or overflow. That is, the reproduction rate and the transfer rate of the stream data are the same, and the buffer is for securing QOS. In the pseudo-streaming type, live delivery is not possible due to a delay caused by buffering. In the streaming type, only the minimum necessary buffer is prepared on the receiving side, and when the receiving side transmits stream data, the reproduction of content is started immediately. In the streaming type, the reproduction rate and transfer rate of the stream data are the same.

  Moreover, it is classified into on-demand delivery and live delivery according to the creation timing of the content delivered by the streaming system. In on-demand distribution, content stream data is created and stored in advance, and transfer of stream data is started in response to a request from the receiving side. In live distribution, stream data is created and distributed at the same time, and stream data is transferred on time.

  Regardless of whether the stream data is transferred using radio waves or transferred using the Internet, if it is transmitted using an unreliable transfer channel, the packet is lost or part of the packet is broken and transferred. Or Therefore, a mechanism for error recovery is incorporated within a range in which real-time performance can be guaranteed, and a mechanism for packet retransmission is incorporated in the protocol.

  However, if the error cannot still be recovered, it can be restored by inferring from the preceding and subsequent packets, or the stream data can be displayed to the user with the error. In broadcasting using radio waves, when the bandwidth of data that can be transferred decreases due to rain or the like, the data quality is lowered and transferred. Even on the Internet, when congestion occurs on a route on the way, the content quality is lowered and transferred.

  In such a case, Patent Document 1 discloses a technique for interrupting transmission when throughput during transfer is reduced and restarting transmission later. Japanese Patent Application Laid-Open No. 2004-228561 discloses a technique for retransmitting a packet later when a packet error occurs when transferring a video captured by a camera terminal to a video storage server.

  On the other hand, as AV broadcasting is digitized, each AV device is connected in order to connect multiple AV devices to each other, to control the other device, and to transfer video and audio streams. It has a terminal based on the IEEE (Institute of Electrical and Electronics Engineers) 1394 serial bus standard (hereinafter referred to as "IEEE1394 standard"), and connects an IEEE1394 standard code to network AV devices. .

  In the IEEE1394 standard, there are two modes for data transfer. One is called Asynchronous communication, which mainly transfers commands for controlling devices. The other is called isochronous communication and is mainly used to transfer video and audio streams between devices. Stream transfer is an abstract concept that defines output and input plugs and channels on a 1394 serial bus to devices, and connects output plugs, channels, channels, and input plugs between devices. By forming a logical transmission path, it is possible to transfer a stream between devices. The transmission line is a point-to-point connection from one output plug to one input plug via one channel, output plug-channel connection without specifying the output plug-input plug pair, and channel-input plug. There is a Broadcast connection that connects

  The IEEE 1394 standard is standardized as “IEEE Std 1394-1995” as “IEEE Standard for a High Performance Serial Bus”. In addition, as a standard for controlling devices between AV devices connected using IEEE1394, "AV / C Digital Interface Command Set General Specification" has been standardized by 1394 TRADE ASSOCIATION (hereinafter referred to as AV / C). ).

JP2003-30083 JP2003-18525

  When the stream data is transferred using the transfer channel with low reliability as described above, the quality deteriorates due to a packet error or the like. There is a problem not only when enjoying the content on time, but also when recording the content on a storage device such as an HDD and enjoying it later. For example, if you are paying money and you are trying to enjoy some content with VOD, for example, if the transfer channel throughput is reduced due to rain, and the content is transferred with a lower quality, the user will try to enjoy the content. Nevertheless, only the poor quality was shown and there is a possibility that it is not convinced to pay the fee. Even more so, if you watch the content on-time on a VOD and record it on the HDD and try to enjoy it later. The method as disclosed in Patent Document 1 is not preferable because in such a case, viewing itself is interrupted. Further, Patent Document 2 discloses a method of retransmitting later, but this is a technique for transferring video captured by a camera terminal to a video storage server. If the transfer channel throughput is poor and high-quality stream data cannot be transferred, a storage device with the same capacity as the image storage server must be installed on the camera terminal side and retransmitted. I can't.

  An object of the present invention is to enable on-time viewing and the like while transferring stream data using a transfer channel with low reliability. Another object of the present invention is to record high-quality stream data on an HDD or the like when recording stream data on a recording device such as an HDD.

  According to an aspect of the present invention, in a stream data transfer system including a stream data transmission system and a stream data reception system, a first data is transmitted between the stream data transmission system and the stream data reception system. A stream data transfer unit; a second data transfer unit that is a data transfer unit having higher reliability than the first stream data; and a control data transfer unit that performs control related to data transfer. A stream data transfer system is provided.

  According to the above system, the stream data to be transferred by having the first stream data transfer means and the second data transfer means that is a data transfer means having higher reliability than the first stream data. Can improve the quality.

  In addition, in a stream data transfer system including a stream data transmission system and a stream data reception system, an on-time for transferring stream data on-time between the stream data transmission system and the stream data reception system A stream data transfer unit; a high-reliability stream data transfer unit that is a data transfer unit having higher reliability than the case of transferring stream data on time; and a control data transfer unit that performs control related to data transfer. A stream data transfer system is provided.

  Control regarding which data transfer is performed can be performed by a control data transfer unit that performs control related to data transfer.

  The stream data transmission system includes: stream data reading means for reading stream data from a stream data source; on-time stream data transmitting means for transmitting stream data on time; and high reliability for transmitting highly reliable stream data It is characterized by comprising stream data transmission means, control data transmission / reception means for transmitting / receiving control data for controlling data transfer, and stream data transmission management means for managing management of stream data.

  The stream data receiving system includes: a writing unit that writes stream data to a stream data storage unit; an on-time stream data receiving unit that receives on-time stream data; and a high-reliability stream that receives high-reliability stream data It comprises data receiving means, control data transmitting / receiving means for transmitting / receiving control data, and stream data reception managing means for managing stream data reception.

  In addition, when there is a stream data transfer request from the stream data receiving side to the stream data transmitting side, the stream data transmitting side transfers the stream data to the stream data receiving side on time, and receives the stream data The side stores the stream data that was received correctly with high quality from the received stream data, and if some data cannot be transferred during the on-time stream data transfer, or the data quality is transferred with the stream quality lowered Stream data that could not be transferred by on-time stream data transfer or high-quality stream data corresponding to stream data transferred with reduced quality is received by reliable stream data transfer. Control to transfer to And features. The stream receiving side stores the transferred stream data and merges it with the stored stream data sent on-time to perform control to form one complete high-quality stream data. And Thereby, the quality of the stream data on the receiving side can be improved later.

  Furthermore, when part of the data cannot be transferred during the transfer of the stream data at the on-time, or when the data is transferred with the quality of the stream being reduced, the stream data receiving side immediately receives the stream data at the on-time. The stream data that could not be transferred by transfer or the stream data transferred with reduced quality is made to be high-quality stream data, and is requested to be re-transferred to the stream data transmitting side by high-reliability stream data transfer, The stream data transmitting side transfers the stream data that could not be transferred or the high-quality stream data corresponding to the stream data transferred with reduced quality to the stream data receiving side by high-reliability stream data transfer. And

  In addition, when part of the data cannot be transferred during the transfer of the stream data at the on-time or when the data transfer is performed with the quality of the stream being reduced, the stream data receiving side Data that could not be transferred by transfer or stream data with reduced stream quality is stored, and after the on-time stream data transfer is completed, the stream data receiving side turns on the stream data transmitting side. Stream data that could not be transferred by stream data transfer in time, or stream data that was transferred by reducing the quality of the stream is requested to be transferred again by highly reliable stream data transfer, the stream data transmitting side, Stream data that could not be transferred or reduced quality The high quality of the stream data corresponding to the feed stream data, and wherein the transferring in reliable stream data transferred to the stream receiving side.

  Furthermore, the stream data stored on the stream receiving side is provided with a storage period, and the stored stream data can be read during the storage period, and the stored stream data is deleted or read after the storage period has passed. It is also possible to make it impossible. A high-quality stream data stored on the receiving side is provided with an expiration date, and when the expiration date expires, the stream data cannot be read.

  According to the present invention, when recording is performed using stream data, complete stream data is recorded by retransmitting a portion that has failed to be transferred or a portion that has been transferred with reduced quality using a reliable communication means. can do.

  That is, the stream data transfer system of the present invention can copy or move the complete stream data by retransmitting the part that failed to be transferred or the part that was transferred with reduced quality using the reliable communication means. it can.

  The stream data transfer system according to the first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration example of a stream data transfer system according to this embodiment.

  In FIG. 1, reference numeral 0001 denotes a stream data transmission system, which is a system capable of transmitting stream data on-time while taking formats such as broadcast, VOD, and NVOD, and transmitting high-quality stream data. . Reference numeral 0002 denotes a stream data receiving system, which is a system that can receive stream data on time and receive high-quality stream data. Reference numeral 0003 denotes on-time stream data transfer means. Reference numeral 0004 denotes a highly reliable stream data transfer means. Reference numeral 0005 denotes control data transfer means.

  The control data is data for performing control related to data transfer. By exchanging control data between the stream data transmission system 0001 and the stream data reception system 0002, for example, control of stream data transfer, retransmission, data transfer using on-time stream data transfer means 0003 and high reliability The control relating to whether to perform data transfer using the unidirectional stream data transfer means 0004 is performed. In addition, information on stream data to be transferred and information on transfer quality on a transmission path to which the stream data is transferred may be exchanged.

  The stream data transmission system 0001 includes a stream data storage unit 0107, a stream data reading unit 0101, a transmission stream data management unit 0102, an on-time stream data transmission unit 0103, a highly reliable stream data transmission unit 0104, a control data transmission / reception unit 0105, a stream Data transmission management means 0106 is provided.

  The stream data reception system 0002 includes a stream data storage unit 0207, a stream data read / write unit 0201, a reception stream data management unit 0202, an on-time stream data reception unit 0203, a highly reliable stream data reception unit 0204, and a control data transmission / reception unit 0205. And stream data reception management means 0206.

  On-time stream data is read from the stream data storage means 0107 using the stream data reading means 0101 of the stream data transmission system 0001, and transferred to the on-time stream data from the on-time stream data transmission means 0103. The data is transferred through the on-time stream data receiving means 0203 of the stream data receiving system 0002 via the means 0003 and written to the stream data storage means 0207 by the stream data reading / writing means 0201.

  On the other hand, stream data with high reliability is read out from the stream data storage unit 0107 using the stream data reading unit 0101 of the stream data transmission system 0001, and the stream data is transmitted from the high reliability stream data transmission unit 0104. The data is transferred through the reliable stream data receiving unit 0204 of the stream data receiving system 0002 via the reliable stream data transferring unit 0004, and written to the stream data storage unit 0207 by the stream data reading / writing unit 0201. Control data for transferring stream data is transferred from the control data transmission / reception means of the stream data transmission system 0001 or the stream data reception system 0002 via the control data transfer means 0005 to the control data transmission / reception means on the other side.

  Stream data transmission management means 0106 manages stream data transmission. Stream data reception management means 0206 manages stream data reception. These check whether or not the packet of the stream data sent is correctly received by the on-time stream data transfer, or whether it is high-quality stream data. If the quality is not high, the packet is stored. Packets that could not be received by the on-time stream data transfer or stream data packets that are not of high quality are retransmitted by the reliable stream data transfer.

  The transmission stream data management unit 0102 manages the stream data transmitted to the stream data reception system 0002. Received stream data management means 0202 manages stream data transmitted from the stream data transmission system. For example, when the storage period of the stream data stored in the stream data receiving system has passed, the stream data is deleted. Further, if the user desires to extend the storage period, processing for that is performed.

  Although FIG. 1 shows a pair of stream data transmission system 0001 and stream data reception system 0002, a plurality of each may be provided.

  As described above, the stream data transfer system shown in FIG. 1 transfers on-time stream data from the stream data transmission system 0001 to the stream data reception system 0002. Can store high quality stream data.

  The stream data transfer system according to the second embodiment of the present invention will be described below. FIG. 2 is a block diagram showing a configuration example of the stream data transfer system according to this embodiment. However, those with the same reference numerals as those in FIG.

  As shown in FIG. 2, the stream data transmission system 0001 according to the present embodiment includes a stream data storage unit 0107, a stream data reading unit 0101, a transmission stream data management unit 0102, an on-time stream data transmission unit 0103, a highly reliable stream. In addition to the data transmission unit 0104, the control data transmission / reception unit 0105, and the stream data transmission management unit 0106, a stream data encryption unit 0108 is provided. The stream data receiving system 0002 includes a stream data storing unit 0207, a stream data reading / writing unit 0201, a received stream data managing unit 0002, an on-time stream data receiving unit 0203, a highly reliable stream data receiving unit 0204, and a control data transmitting / receiving unit 0205. In addition to the stream data reception management means 0206, stream data decoding means 0208 is provided.

  In FIG. 2, when stream data is transferred by on-time stream data transfer and high-reliability stream data transfer, the stream data transmission system 0001 uses the stream data encryption unit 0108 to encrypt the stream data, The stream data receiving system 0002 uses the stream data decoding unit 0208 to decode the stream data.

  Although FIG. 2 shows a pair of stream data transmission system and stream data reception system, a plurality of each may be provided.

  The stream data transfer system shown in FIG. 2 transfers on-time stream data from the stream data transmission system 0001 to the stream data reception system 0002. Furthermore, the stream data reception system 0002 receives high-quality stream data. Saving is possible.

  The stream data encryption / stream data decryption shown in FIG. 2 can be realized using a known technique, for example, a secret key encryption system. Alternatively, it can be realized using a public key cryptosystem.

  A stream data transfer system according to the third embodiment of the present invention will be described below with reference to the drawings. FIG. 3 is a block diagram showing a configuration example of the stream data transfer system according to this embodiment. However, the description with the same reference numerals is omitted.

  The stream data transfer system shown in FIG. 3 includes a stream data transmission system 0001, a stream data reception system 0002, and data transfer means (0006). The configurations of the stream data transmission system 0001 and the stream data reception system 0002 are the same as those shown in FIG. However, the data transfer between the stream data transmission system 0001 and the stream data reception system 0002 is performed using the data transfer means 0006. That is, the data transfer means 0006 performs on-time stream data transfer, high-reliability stream data transfer, and control data transfer.

  In an exemplary sense rather than a restrictive sense, FIG. 1 mainly includes stream transfer using broadcasting, and FIG. 3 includes stream transfer using the Internet.

  Although FIG. 3 shows a pair of the stream data transmission system 0001 and the stream data reception system 0002, there may be a plurality of each. The stream data transfer system shown in FIG. 3 transfers on-time stream data from the stream data transmission system 0001 to the stream data reception system 0002. Furthermore, the stream data reception system 0002 receives high-quality stream data. Saving is possible.

  A stream data transfer system according to the fourth embodiment of the present invention will be described below with reference to the drawings. FIG. 4 is a block diagram showing a configuration example of a stream data transfer system according to this embodiment. However, the description of the same reference numerals as those in FIG. 1 is omitted.

  As shown in FIG. 4, the stream data transfer system according to the present embodiment includes a stream data transmission system, a stream data reception system, and data transfer means. The configurations of the stream data transmission system 0001 and the stream data reception system 0002 are the same as those shown in FIG. However, the data transfer between the stream data transmission system 0001 and the stream data reception system 0002 is performed using the data transfer means 0006. That is, the data transfer means 0006 performs on-time stream data transfer, high-reliability stream data transfer, and control data transfer. Although FIG. 4 shows a pair of stream data transmission system and stream data reception system, a plurality of each may be provided.

  The stream data transfer system shown in FIG. 4 transfers on-time stream data from the stream data transmission system 0001 to the stream data reception system 0002. Furthermore, the stream data reception system 0002 receives high-quality stream data. Saving is possible. The stream data encryption / stream data decryption shown in FIG. 4 can be realized using a known secret key encryption system. Alternatively, it can be realized using a public key cryptosystem.

  A stream data transfer system according to a fifth embodiment of the present invention will be described below with reference to the drawings. Reference numeral 1001 denotes a digital terrestrial broadcast receiving terminal capable of recording stream data. Reference numeral 1002 indicates an Internet service provider. Reference numeral 1003 indicates an Internet network. Reference numeral 1005 indicates a terrestrial digital broadcasting station. Reference numeral 1004 denotes a computer system that transmits stream data through the Internet installed in a broadcasting station. Reference numeral 1006 denotes a terrestrial digital broadcasting radio tower for transmitting terrestrial digital broadcasting. Reference numeral 1007 denotes a terrestrial digital broadcast receiving antenna. A terrestrial digital broadcast receiving terminal 1001 is connected to the Internet and can be used as a return channel for terrestrial digital broadcast. Also, stream data can be received.

  In FIG. 5, stream data is broadcast and received by the receiving terminal 1001 through terrestrial digital broadcasting. The receiving terminal 1001 records the broadcast stream data on the HDD or the like while reproducing it. If necessary, stream data can be reproduced on the display on time. When there is a packet that cannot receive the correct stream data while receiving the stream data by terrestrial digital broadcasting, or when the quality of the stream data broadcast from the terrestrial digital broadcasting is lowered due to the weather, etc. Then, the packet that could not be received or the packet of stream data that was broadcast with reduced quality is transferred. Then, the recorded stream data is made complete.

  Stream data transferred from a terrestrial digital broadcasting station or stream data acquired via the Internet is MPEG2-TS or H.264. It is possible to transfer H.264 encoded data. Also, stream data or control data acquired through the Internet can be transferred by the HTTP protocol. It is also possible to receive stream data through a return channel of terrestrial digital broadcasting.

  FIG. 5 shows a case where the broadcasting station and the receiving terminal are paired, but there may be a plurality of broadcasting stations and receiving terminals. The stream data transfer system shown in FIG. 5 enables on-time transfer of stream data from the stream data transmission system to the stream data reception system, and high-quality stream data can be stored in the stream data reception system. It becomes. It is also possible to encrypt the stream data and transfer it. At that time, a secret key encryption system or a public key encryption system can be used as the encryption system.

  Next, a stream data transfer system according to a sixth embodiment of the present invention will be described with reference to FIG. However, the description of the same reference numerals as those in FIG. 5 is omitted.

  Reference numeral 1008 indicates a ground facility for BS digital broadcasting. Reference numeral 1009 denotes a satellite broadcasting station for BS digital broadcasting. Reference numeral 1010 denotes an antenna for receiving BS digital broadcasting. Reference numeral 1011 denotes a BS digital broadcast receiving terminal capable of recording stream data. Reference numeral 1012 indicates a BS digital broadcast station. The BS digital broadcast receiving terminal 1011 is connected to the Internet and can be used as a return channel for BS digital broadcast. In addition, stream data can be received.

  In FIG. 6, stream data is broadcast and received by the receiving terminal 1011 through BS digital broadcasting. The receiving terminal 1011 records the broadcast stream data in a storage device such as an HDD. Also, stream data is displayed on the display as needed on time. If there is a packet that cannot receive the correct stream data while receiving the stream data by BS digital broadcasting, or if the quality of the stream data broadcast from BS digital broadcasting is lowered due to weather etc. The recorded stream data is completed by transferring packets that could not be received via the Internet or packets of stream data that had been broadcast with reduced quality.

  The stream data transferred from the BS digital broadcasting station or the stream data acquired through the Internet is MPEG2-TS or H.264. It is possible to transfer H.264 encoded data. In addition, stream data or control data acquired through the Internet can be transferred by the HTTP protocol. It is also possible to receive stream data through the return channel of BS digital broadcasting. Although FIG. 6 shows a configuration in which a broadcasting station and a receiving terminal are paired, a plurality of each may be provided.

  The stream data transfer system shown in FIG. 6 transfers stream data from the stream data transmission system to the stream data reception system on time, and the stream data reception system stores high-quality stream data. It becomes possible. It is also possible to encrypt the stream data and transfer it. At that time, a secret key encryption system or a public key encryption system can be used as the encryption system.

  Although FIG. 6 shows a system in the BS digital broadcasting system, the BS digital broadcasting system can be replaced with a CS digital broadcasting system.

  Next, a stream data transfer system according to a seventh embodiment of the present invention will be described with reference to FIG. However, description of the components having the same reference numerals as those in FIGS. 5 and 6 is omitted.

  In FIG. 7, reference numeral 1013 denotes a CATV broadcasting station. Reference numeral 1004 denotes a stream data display device. Reference numeral 1015 denotes a STB for broadcast reception using CATV, which can record stream data.

  In FIG. 7, the stream data is broadcast through the broadcast by CATV, and is received by the receiving terminal indicated by the STB 1015 for broadcast reception. In the receiving terminal 1014, the data is recorded in a broadcast storage device such as an HDD. If necessary, the stream data is reproduced on the display of the stream data display device 1004 on time. When there is a packet that cannot receive the correct stream data while receiving the stream data by broadcasting by CATV, or when the broadcast is made with the quality of the stream data broadcast from the CATV broadcast being lowered for some reason. By using the Internet facility, the recorded stream data is made complete by retransmitting the packet that could not be received or the packet of the stream data that was broadcast with reduced quality.

  The stream data transferred from the CATV broadcasting station or the stream data acquired through the Internet facility is MPEG2-TS or H.264. It is possible to transfer H.264 encoded data. In addition, stream data or control data acquired through the Internet can be transferred by the HTTP protocol.

  FIG. 7 shows a case where a pair of broadcasting stations and receiving terminals are provided, but a plurality of each may be provided. The stream data transfer system shown in FIG. 7 transfers stream data from the stream data transmission system to the stream data reception system on time, and the stream data reception system stores high-quality stream data. It becomes possible. It is also possible to encrypt the stream data and transfer it. At that time, a secret key encryption system or a public key encryption system can be used as the encryption system.

  Next, a stream data transfer system according to an eighth embodiment of the present invention will be described with reference to FIG. However, the description of the same reference numerals will be omitted.

  Reference numeral 1016 denotes an STB for Internet broadcasting that can record stream data. Reference numeral 1017 denotes a service provider that provides Internet broadcasting.

  In FIG. 8, on-time stream data is broadcast through the Internet broadcast and received by the receiving terminal indicated by the STB 1016 for Internet broadcasting. The receiving terminal records the broadcast stream data in a storage device such as an HDD. If necessary, stream data is reproduced on the display on time. While receiving stream data of the Internet broadcast on time, if there is a packet that cannot receive the correct stream data, or for some reason, the quality of the stream data broadcast from the Internet broadcast on time is reduced. If the packet is not received, or the packet of stream data that has been broadcast with reduced quality is retransmitted from a highly reliable protocol, the recorded stream data is made complete. To do.

  Stream data transferred on time or stream data acquired by a highly reliable protocol is MPEG2-TS or H.264. H.264 encoded data can be transferred. A protocol for transferring stream data on time can be transferred by the RTP protocol. Stream data or control data transferred by the high reliability protocol can be transferred by the HTTP protocol.

In FIG. 8, a broadcasting station and a receiving terminal are shown as a pair, but a plurality of each may be provided.
The stream data transfer system shown in FIG. 8 transfers on-time stream data from the stream data transmission system to the stream data reception system, and the stream data reception system stores high-quality stream data. It becomes possible. It is also possible to encrypt the stream data and transfer it. At that time, a secret key encryption system or a public key encryption system can be used as the encryption system.

  Next, a stream data transfer system according to a ninth embodiment of the present invention will be described with reference to FIG. In FIG. 9, two recording devices 2001 and 2002 having a connection function of IEEE1394 standard and a device 2003 having a connection function of IEEE1394 standard are connected by a cable 2004 of IEEE1394 standard. IEEE1394 standard devices are connected in a daisy chain. In addition, each device can be dynamically disconnected or connected. When an IEEE1394 standard device is connected or disconnected, a reset operation (bus reset) occurs on the IEEE1394 standard bus, and the connection configuration is once again performed on all devices. Here, if a bus reset occurs while something is operating between devices connected by IEEE1394, the operation is interrupted and the operation is resumed when the bus reset operation is completed. . However, since the device continues to operate even during interruption due to the bus reset, data due to data transfer or the like during the bus reset operation is lost. For example, in FIG. 9, when stream data is being copied from the device 2001 to the device 2002, if the device 2003 is disconnected from the IEEE1394 device, a bus reset occurs and the device 2001 to the device 2002 during the bus reset operation. Data transferred to is lost.

  Normally, in the IEE1394 standard, transfer of stream data such as video and audio is performed using isochronous communication. Here, when a bus reset occurs during isochronous communication and stream data is lost during that time, the lost packet is retransmitted using asynchronous communication different from isochronous communication. Thus, complete stream data can be transferred.

  Stream data transferred by isochronous communication or stream data transferred by asynchronous communication is MPEG2-TS or H.264. It is possible to transfer H.264 encoded data.

  As described above, when copying or moving stream data between IEEE1394 standard devices using isochronous communication, even if some packets of stream data are lost due to bus reset, etc., asynchronous communication is used. By transferring the lost packet, high-quality stream data can be copied or moved. It is also possible to encrypt the stream data and transfer it. At that time, a secret key encryption system or a public key encryption system can be used as the encryption system.

  FIG. 10 is a diagram showing a protocol stack used when performing on-time stream data transfer or high-reliability stream data transfer using the Internet. In the on-time stream data transfer, the UDP protocol is used on top of the IP protocol, and the RTP protocol is used on the UDP protocol. In the reliable stream data transfer, the TCP protocol is used over the IP protocol, and the HTTP protocol is used for transfer over the IP protocol.

  FIG. 11 is an example showing a situation when stream data is transferred on time. In this example, the packets with the packet numbers 4 and 8 cannot be transferred to the receiving side. Therefore, in order to make up for the packet that failed to be transferred, the receiving side uses the previous and subsequent received packets to make an estimation. Normally, when transferring stream data, FEC (Forward Error Correction) or CRC (Cyclic Redundancy Check) is used to check whether the stream data to be transferred is broken or not. Append data to the packet. The receiving side checks the FEC and CRC and corrects if the packet is broken. If the packet cannot be corrected with the data added by FEC or CRC, the packet is discarded. In addition, a sequence number is simply added to a packet to be transmitted, packets with consecutive sequence numbers are transmitted, and the receiving side checks whether the packet is lost in the middle of the transmission path. In the case of FIG. 11, it is shown that the packets of the packet numbers 4 and 8 cannot be transferred because the packets are lost on the transmission path.

  FIG. 12 shows how data is exchanged between the stream data transmission system 3003 and the stream data reception system 3001 when performing on-time stream data transfer and highly reliable stream data transfer using the Internet. FIG.

  First, a stream data transmission request is made from the stream data receiving system 3001. The stream data receiving system 3001 returns the result (stream data transmission response). During this time, information necessary for stream data transfer, such as which stream data is transferred, is exchanged. The stream data transmission system 3003 reads the selected stream data from the storage device 3005 such as an HDD, and transmits it as a packet to the stream data reception system 3001. In the stream data receiving system 3001, if the received stream data packet is complete, it is reproduced on the display 3010 while being recorded in the storage device 3007b such as an HDD. If a packet is lost in the middle or if the received packet is incomplete, the stream data is reproduced on the receiving side by using the preceding and succeeding packets (the i-th packet in the figure). ). The packet number is recorded (3007a). Then, after all the packets of the stream data have been transferred, the stream data receiving system 3001 requests the stream data transmitting system 3003 to retransmit the packet that could not be received by the packet number (stream data retransmission request). When the stream data transmission system 3003 receives the stream data retransmission request, the stream data transmission system 3003 retransmits the stream data packet designated by the stream data reception system 3001 based on the packet number. In the stream data receiving system 3001, when the retransmitted packet is received, it is recorded and complete stream data can be recorded.

  In this case, the stream data is transferred on time using the RTP protocol that has real-time properties but low reliability. Also, stream data is transferred at the time of retransmission, although it is not real-time, but is transferred using a highly reliable HTTP protocol. FIG. 13 shows data exchanged between the stream data transmission system 3003 and the stream data reception system 3001 when performing on-time stream data transfer and reliable stream data transfer using the Internet. FIG. In FIG. 12, the stream data receiving system 3001 retransmits the packet that could not be received after the transfer of the stream data was completed, but in FIG. 13, the retransmission was performed during the transfer of the stream data on time. Is different.

  FIG. 14 shows data exchanged between a stream data transmission system and a stream data reception system when performing on-time stream data transfer and reliable stream data transfer using the Internet. is there. In FIG. 14, when the communication path throughput decreases due to congestion or the like on the communication path, and high-quality stream data cannot be transferred, the stream data transmission system 3003 converts the stream data into low-quality stream data, and the stream data reception system. Shows the situation to transfer to. That is, the stream data receiving system 3001 does not record stream data while the throughput of the communication path is reduced and low-quality stream data is transferred (from the i-th to the j-th). In addition, the packet numbers (from i-th to j-th) in the meantime are recorded in the storage device 3007a. Then, after the transfer of the stream data is completed, the stream data receiving system 3001 requests the stream data transmitting system 3003 to retransmit the stream data received with low quality (stream data retransmission request). Upon receiving the stream data retransmission request, the stream data transmission system 3003 retransmits the designated stream data packet to the stream data reception system 3001. The stream data to be retransmitted to the stream data receiving system is high quality data. When the stream data receiving system 3001 receives the retransmitted packet and records it in the storage device 3007b, it is possible to record high-quality and complete stream data.

FIG. 15 is a diagram illustrating a flow of packets from the stream data transmission system to the stream data reception system.
In FIG. 15, the stream data is transferred on time, but the data of the fourth packet number and the eighth data of the packet number are lost in the middle as indicated by dotted lines. At that time, in the reproduction of the stream data on the receiving side 3001, the data of the lost packet is estimated by using the previous and subsequent packets. Also, correctly received packets are recorded. On the other hand, the stream data transmission system 3001 requests the stream data transmission system 3003 to retransmit the fourth and eighth packets that could not be received. Retransmit the 8th packet. When the stream data receiving system receives the retransmission data, it records it and stores it as complete stream data.

  FIG. 16 is a diagram showing a sequence for deleting stream data recorded in the stream data receiving system 3001. When the stream data reception system 3001 transmits a stream data transmission request to the stream data transmission system 3003, the stream data transmission system returns a stream data transmission response to the stream data reception system. Thereafter, the stream data of the designated content is transmitted from the stream data transmission system 3003 to the stream data reception system 3001. In the stream data receiving system 3001, the stream data is reproduced on the display 3010 on time, and the stream data is stored in the storage device 3007. In addition, a packet that failed to be transferred in the on-time stream data transfer is retransmitted from the storage device 3005 by the highly reliable stream data transfer, and the complete stream data is stored in the stream data receiving system 3001. Here, the stream data stored in the stream data receiving system can have an expiration date. Until the expiration date, the stream data stored in the storage device 3007 of the stream data receiving system can be retrieved at any time, and the user can reproduce it.

  In FIG. 16, in order to prevent reading after the expiration date of the stream data stored in the storage device 3007 of the stream data reception system 3001, after the transfer of the stream data is completed on the stream data transmission system 3003, Set the timeout event to occur when the stream data expires. When a timeout occurs, the stream data transmission system 3003 transmits a stream data deletion request to the stream data reception system 3001. When receiving the stream data deletion request, the stream data receiving system 3001 deletes the stream data stored in the storage device 3007.

  As a result, an expiration date of the stream data stored in the storage device 3007 of the stream data receiving system 3001 is provided, and when the expiration date has expired, the stream data cannot be used. Note that FIG. 16 shows an example in which the stream data stored in the storage device 3007 is deleted, but it is only necessary that the stream data stored in the storage device 3007 on the stream data receiving side 3001 cannot be read. . Therefore, instead of deleting, the stream data may not be read by other methods such as encryption.

  FIG. 17 is a diagram showing a processing sequence for extending the expiration date of stream data recorded in the stream data receiving system. In FIG. 17, the process from the stream data transmission system 3003 to the stream data reception system 3001 is similar to that in FIG.

  When the stream data reception system 3001 receives a stream data deletion request signal from the stream data transmission system 3003 according to the set timeout, the stream data reception system 3001 deletes the stream data or extends the storage to the user. Dialog 3010b is displayed. When the user selects deletion of stream data based on this display, the stream data receiving system 3001 deletes the stream data.

  When the user selects extension of the period related to storage of stream data (storage extension), the stream data reception system 3001 transmits a stream data storage extension request to the stream data transmission system 3003. When the stream data transmission system 3003 receives the stream data storage extension request, the stream data transmission system 3003 sets a timeout for re-delimiting the expiration date for the stream data. By this process, the expiration date of the stream data stored in the stream data receiving system 3001 can be extended. If the user does not request an extension when the expiration date has expired, the stream data cannot be used. When the user requests extension of the expiration date, the expiration date is reset. In FIG. 17, the stored stream data is deleted. However, it is only necessary that the stream data stored on the stream data receiving system 3001 side cannot be read. Therefore, other methods such as encryption of stream data instead of deletion may be used.

  FIG. 18 is a diagram showing a processing sequence for deleting stream data recorded in the stream data receiving system 3001. 18, since the stream data is transferred from the stream data transmission system 3003 to the stream data reception system 3001 and the stream data is stored in the stream data reception system 3001, the description is omitted. In FIG. 18, since the stream data stored in the stream data receiving system 3001 cannot be read after the expiration date, the stream data expires after the transfer of the stream data is completed on the stream data receiving system 3001. And set the timeout to generate a timeout event. When a timeout occurs, the stream data receiving system 3001 deletes the stored stream data.

  As a result, the expiration date of the stream data stored in the stream data receiving system 3001 can be set, and when this expiration date expires, the stream data cannot be used. In FIG. 18, the stored stream data is deleted. However, since it is not necessary to read the stream data stored on the stream data receiving side, other methods such as encrypting the stream data may be used. .

  FIG. 19 is a diagram showing a sequence for extending the expiration date of stream data recorded in the stream data receiving system 3001. In FIG. 19, since the stream data receiving system 3001 is the same as FIG. 18 until a time-out event occurs in order to delete the stream data, description thereof is omitted. When the stream data receiving system 3001 receives a timeout event for deleting stream data, the stream data receiving system 3001 displays a dialog 3010b for deleting the stream data or extending the storage to the user. In response to this display, when the user selects deletion of stream data, the stream data receiving system 3001 deletes the stream data. When the user selects the extension of storage of stream data, the stream data receiving system 3001 sets a timeout for re-delimiting the expiration date for the stream data. As a result, the validity period of the stream data stored in the stream data receiving system 3001 can be extended, and if the user does not request an extension when the validity period expires, the stream data cannot be used. When the user requests extension of the expiration date, the expiration date is reset. In FIG. 19, the stored stream data is deleted, but it is only necessary to make it impossible to read the stream data stored on the stream data receiving system 3001 side. The method may be used.

  As described above, according to the present embodiment, an HDD is used while using stream data such as transferring stream data using an unstable communication path and viewing the stream data on time. In the case of recording on the recording medium, the recorded stream data is recorded on the HDD or the like without being completely transferred due to the failure of the stream data transfer or the change of the transmission path. The stream data transfer system can record the complete stream data on the HDD or the like by retransmitting the part that has failed to be transferred or the part that has been transferred with reduced quality using the reliable communication means.

  Even if the stream data is not used on time, when copying or moving the stream data using IEEE1394 or the like, the transfer of the stream data is disturbed due to a bus reset or the like, and the complete stream data copy or move is performed. In some cases, the stream data transfer system of the present invention can copy the complete stream data by retransmitting the part that failed to be transferred or the part that was transferred with reduced quality using a reliable communication means. Can move.

  Further, an expiration date can be set for the stream data stored in the stream data receiving system, and when the expiration date has passed, the stream data can be made unreadable.

  Further, an expiration date can be set for the stream data stored in the stream data receiving system, and when the expiration date has passed, the expiration date can be extended.

  As described above, the respective embodiments related to the control of the stream data transfer system according to the embodiment of the present invention have been described in the above embodiments. However, the present invention is not limited to the stream data as described in the method executed by the computer. It can also take the form of a control method for the transfer system. Further, similar to the control device of the stream data transfer system having these functions, as a program for causing a computer to function as the control device of the stream data transfer system or for executing the control method of the stream data transfer system This form is also possible.

  An embodiment of a recording medium storing a program and data for realizing each function according to the present invention will be described. Specific recording media include CD-ROM (-R / -RW), magneto-optical disk, DVD-ROM (-RW / + RW / -R / + R / -RAM), floppy disk, flash memory, memory Cards, memory sticks and other various ROMs and RAMs can be assumed, and the functions of the embodiments of the present invention described above can be executed by these computers on these recording media, and programs for realizing the functions can be recorded and distributed. This facilitates the realization of the function. Then, the recording medium is mounted on the information processing apparatus such as a computer and the program is read by the information processing apparatus as described above, or the program is stored in the recording medium included in the information processing apparatus and read as necessary. Thus, each function related to the present invention can be executed. Therefore, the above embodiments are also included in the scope of the present invention.

  The present invention can be used as a stream data transfer system.

It is the block diagram which showed one structural example of the transfer system of the stream data by the 1st Embodiment of this invention. It is the block diagram which showed the transfer system of the stream data by the 2nd Embodiment of this invention. It is the block diagram which showed the transfer system of the stream data by the 3rd Embodiment of this invention. It is the block diagram which showed the transfer system of the stream data by the 4th Embodiment of this invention. It is the figure which showed the transfer system of the stream data by the 5th Embodiment of this invention. It is the figure which showed the transfer system of the stream data by the 6th Embodiment of this invention. It is the figure which showed the transfer system of the stream data by the 7th Embodiment of this invention. It is the figure which showed the transfer system of the stream data by the 8th Embodiment of this invention. It is the figure which showed the transfer system of the stream data by the 9th Embodiment of this invention. It is the figure which showed the protocol hierarchy in an internet protocol. It is the figure which showed the mode of the transfer of stream data. It is the figure which showed the sequence at the time of the stream data transfer by embodiment of this invention. It is the figure which showed the sequence at the time of the stream data transfer by embodiment of this invention. It is the figure which showed the sequence at the time of the stream data transfer by embodiment of this invention. It is the figure which showed the flow of the stream data at the time of the stream data transfer by embodiment of this invention. It is the figure which showed the sequence which deletes the preserve | saved stream data by embodiment of this invention. It is the figure which showed the sequence which deletes the preserve | saved stream data by embodiment of this invention. It is the figure which showed the sequence which deletes the preserve | saved stream data by embodiment of this invention. It is the figure which showed the sequence which deletes the preserve | saved stream data by embodiment of this invention.

Explanation of symbols

0001 ... Stream data transmission system, 0002 ... Stream data reception system, 0003 ... On-time stream data transfer means, 0004 ... High reliability stream data transfer means, 0005 ... Control data transfer means, 0006 ... Data transfer means, 0101 ... Stream data Reading means, 0102 ... received stream data management means, 0103 ... on-time stream data transmission means, 0104 ... high reliability stream data transmission means, 0105 ... control data transmission / reception means, 0106 ... stream transmission management means, 0107 ... stream data storage means , 0108 ... Stream data encryption means, 0201 ... Stream data read / write means, 0202 ... Receive stream data management means, 0203 ... On-time stream data reception means, 0204 ... High reliability stream data reception means, 0205 ... Control data Transmission / reception means, 0206 ... Stream data reception management means [0207] Stream data storage means, 0208 ... Stream data decoding means, 1001 ... Terrestrial digital broadcast receiving terminal with stream data recording function, 1002 ... Internet service provider, 1003 ... Internet network, 1004 ... Computer for stream data transmission processing, 1005 ... Digital terrestrial broadcasting station, 1006 ... Digital terrestrial broadcast tower, 1007 ... Digital terrestrial broadcast receiving antenna, 1008 ... Satellite broadcasting ground equipment, 1009 ... Satellite broadcasting satellite, 1010 ... Satellite broadcasting receiving antenna, 1011 ... With stream data recording function BS digital broadcasting receiving terminal, 1012 ... BS digital broadcasting station, 1013 ... CATV broadcasting station, 1014 ... Stream data display terminal, 1015 ... STB for receiving CATV, 1016 ... STB receiving stream data using the Internet, 1017 ... Provider providing stream data using the Internet, 2001, 2002… Recording equipment with IEEE1394 standard connection function, 2003 ... Equipment with IEEE1394 standard connection function, 2004 ... IEEE1394 standard cable.

Claims (27)

In a stream data transfer system comprising a stream data transmission system and a stream data reception system,
Between the stream data transmission system and the stream data reception system, a first stream data transfer unit and a second data transfer unit which is a data transfer unit having higher reliability than the first stream data A stream data transfer system comprising: control data transfer means for controlling data transfer. In a stream data transfer system comprising a stream data transmission system and a stream data reception system,
On-time stream data transfer means for transferring stream data on-time between the stream data transmission system and the stream data reception system, and data having higher reliability than the case of transferring stream data on-time A stream data transfer system, comprising: a highly reliable stream data transfer unit that is a transfer unit; and a control data transfer unit that performs control related to data transfer. The stream data transmission system includes:
Stream data reading means for reading stream data from a stream data source;
On-time stream data transmission means for transmitting stream data on-time;
A highly reliable stream data transmission means for transmitting highly reliable stream data;
Control data transmission / reception means for transmitting / receiving control data for controlling data transfer; and
3. The stream data transfer system according to claim 1, further comprising stream data transmission management means for performing management related to transmission of stream data. The stream data receiving system includes:
Writing means for writing the stream data to the stream data storage means;
On-time stream data receiving means for receiving on-time stream data;
High-reliability stream data receiving means for receiving high-reliability stream data;
Control data transmitting and receiving means for transmitting and receiving control data;
The stream data transfer system according to any one of claims 1 to 3, further comprising: a stream data reception management unit that performs management related to reception of stream data. A stream data transmission system, a stream data receiving system, and a stream data transfer system comprising:
A stream data transfer system comprising data transfer means for performing on-time stream data transfer, highly reliable stream data transfer, and control data transfer between the stream data transmission system and the stream data reception system. .   6. The on-time stream data is transferred using a digital broadcasting system, and the high-reliability stream data and the control data are transferred using a return channel of the digital broadcasting system. The stream data transfer system according to any one of the above.   The stream data transfer system according to claim 6, wherein the broadcast system is at least one of a terrestrial digital broadcast system and a satellite digital broadcast system.   The stream data transfer system according to claim 6 or 7, wherein the return channel uses an IP network.   9. The stream data transfer system according to claim 8, wherein the highly reliable stream data and control data transferred using the IP network of the return channel are transferred using an HTTP protocol.   6. The stream data transfer system according to claim 5, wherein the data transfer means uses an IP network.   11. The stream data transfer system according to claim 10, wherein the on-time stream data transfer transferred using the IP network is transferred using an RTP protocol.   The stream data transfer system according to claim 10 or 11, wherein the reliable stream data and control data transferred using the IP network are transferred using an HTTP protocol.   An IEEE 1394 standard network is used as the data transfer means, and on-time stream data transfer transferred using the IEEE 1394 standard network is transferred using isochronous communication, and high reliability is transferred using the IEEE 1394 standard network. 6. The stream data transfer system according to claim 5, wherein the stream data and the control data are transferred using asynchronous communication.   The stream according to any one of claims 1 to 13, wherein the stream data transmission system includes a stream data encryption unit, and the stream data reception system includes a stream data decryption unit. Data transfer system.   15. The stream data transfer system according to claim 14, wherein the stream data encryption unit and the stream data decryption unit are at least one of a secret key encryption system and a public key encryption system.   The stream data transfer system according to any one of claims 1 to 15, wherein the stream data is encoded by MPEG2-TS or H.264.   When there is a stream data transfer request from the stream data receiving side to the stream data transmitting side, the stream data transmitting side transfers the stream data to the stream data receiving side on time, and the stream data receiving side Of the received stream data, the stream data that could be received correctly with high quality was saved, and when some data could not be transferred during the on-time stream data transfer, or the data was transferred with the stream quality degraded In this case, stream data that could not be transferred by on-time stream data transfer or high-quality stream data corresponding to stream data transferred with reduced quality is transferred to the stream receiver by high-reliability stream data transfer. It is characterized by performing control to transfer Stream data transfer system according to any one of claims 1 to 16.   The stream receiving side stores the transferred stream data and merges it with the stored stream data sent on-time to perform control to form one complete high-quality stream data. The stream data transfer system according to claim 17.   If some data cannot be transferred during transfer of the on-time stream data, or if data transfer is performed with a reduced quality of the stream, the stream data receiving side can immediately transfer the stream data on-time. The stream data that could not be transferred or the stream data transferred with reduced quality is converted into high-quality stream data, and the stream data is requested to be re-transferred to the stream data transmission side by high-reliability stream data transfer. The transmitting side transfers stream data that could not be transferred or high-quality stream data corresponding to stream data transferred with reduced quality to the stream data receiving side by high-reliability stream data transfer. The stream data transfer system according to claim 17.   When part of the data cannot be transferred during the transfer of the on-time stream data or when the data transfer is performed with the quality of the stream being reduced, the stream data receiving side can transfer the stream data on-time. Store the data that could not be transferred or stream data with reduced stream quality, and after the on-time stream data transfer is completed, the stream data receiving side sends the stream data transmitting side to the stream data transmitting side on-time. Stream data that could not be transferred by the stream data transfer or stream data that had been transferred with reduced stream quality is requested to be transferred again by the highly reliable stream data transfer, and the stream data transmission side can transfer The stream data that did not exist or transferred with reduced quality Stream data transfer system of claim 19, the quality of the stream data corresponding to the stream data, and wherein the transferring in reliable stream data transferred to the stream receiving side.   The stream data stored on the stream receiving side is provided with a storage period. During the storage period, the stored stream data can be read, and when the storage period has passed, the stored stream data is deleted or cannot be read. The stream data transfer system according to any one of claims 17 to 20, wherein It is possible to set to generate a timeout event when the stream data transfer is completed on the stream transmission side and the storage period of the stream data stored on the stream data reception side has elapsed,
When a time-out event occurs on the stream transmission side, a content deletion request message is transmitted to the stream reception side, and the content reception request message is received on the stream reception side, and stored stream data is deleted or read. The stream data transfer system according to claim 21, wherein the stream data transfer system is disabled. After completion of the transfer of the stream data on the stream transmission side, it is possible to set to generate a timeout event when the storage period of the stream data stored on the stream data reception side elapses.
When a timeout event occurs on the stream transmission side, a content deletion request message is transmitted to the stream reception side, and the stream reception side confirms whether to delete the content or extend the storage to the user, In the case of deletion, the stored stream data is deleted or cannot be read, and when extension of storage is requested, a content storage extension request message is transmitted to the stream transmission side, and the stream reception side The stream data transfer system according to claim 21, wherein a timeout event is generated again when a storage period of the stored stream data elapses.   It is possible to set a time-out event to be generated when the stream data transfer is completed on the stream receiving side and the storage period of the stored stream data elapses. When the time-out event occurs, the stored stream data is deleted. 23. The stream data transfer system according to claim 21, wherein the stream data transfer system is unreadable. When the stream receiver completes the transfer of the stream data and the storage period of the stored stream data has passed, it can be set to generate a timeout event,
When a time-out event occurs, the user is asked whether to delete the content or to extend the storage, and if it is deleted, the stored stream data is deleted or cannot be read and stored. 22. The stream data transfer system according to claim 21, wherein when the extension of the stream data is extended, a setting is made to generate a time-out event when the storage period of the stream data stored again elapses.   The program for making a computer perform the function of the content transfer system of any one of Claim 1-25.   A computer-readable recording medium on which the program according to claim 26 is recorded.

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