JP2003115824A - Data receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To rightly reproduce data which are received just to the partway, when data of video or audio are received by a terminal with small memory capacity. SOLUTION: A data receiving part 201 writes data received from a delivery server 102 into a data storage part 202 and when the size of the data stored in the data storage part 202 reaches a limited size Smax , receiving of data is interrupted. When a repair request is received from a reproducing part 204, a data repair part 205 repairs the data stored in the data storage part 202 while being interrupted into state based on a prescribed data format. The data repair part 205 implements three kinds of processing for deciding whether data can be repaired or not, correcting the terminal part of the data and updating additional information presenting the attribute of the data. The reproducing part 204 reproduces the data repaired by the data repair part 205.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data receiving apparatus for receiving and accumulating data reproduced in time series, such as video and audio data, and more particularly to a data receiving apparatus having a memory capacity such as a portable information terminal. The present invention relates to a data receiving device capable of suitably adapting a small terminal to a data distribution service such as video and audio.

[0002]

2. Description of the Related Art In recent years, the network technology for connecting to the Internet has advanced, and the data transmission rate on the Internet has been remarkably improved. Along with this, services for distributing contents such as video and audio data, which have not been distributed so far due to the large amount of data, have become popular.

Network technology continues to advance in the field of wireless communication as well as in the field of wired communication. Also in the field of wireless communication, a service for providing a third-generation mobile communication technology has been started, and in the future, various services will be provided by utilizing a data transmission speed significantly improved as compared with the conventional one. As one of them, it is expected that services for distributing contents having a large amount of data such as video and audio data will be expanded.

On the other hand, typical examples of portable information terminals that wirelessly access the Internet are portable telephones and personal digital assistants.
tant: PDA) and the like. However, the capacities of the memories mounted on these portable information terminals have not so rapidly increased as compared with the improvement of the data transmission rate of wireless communication due to the constraints of cost and mounting size. Therefore, in mobile information terminals that receive contents delivered wirelessly, how to store received contents becomes a major issue in response to the increase in the data amount of contents accompanying the improvement of data transmission speed. ing.

The small memory capacity of the portable information terminal has been a problem before the data transmission rate of wireless communication was increased. As a method for solving this problem, conventionally, a method of acquiring only a part of the received content or selecting and acquiring only a specific type of content has been used. For example, in Japanese Patent No. 3123989 “Information terminal device, electronic mail restricted receiving method and recording medium recording electronic mail restricted receiving program”, a very large size mail is received when an electronic mail is received by a portable information terminal. A technique is disclosed in which the acquisition of the mail text is limited to a preset size in order to prevent the terminal memory from becoming full due to the reception of one message.

[0006] However, this electronic mail system is designed to acquire only the mail text up to the limited size and uniformly delete the data such as video and audio attached to the electronic mail. For this reason, it is hard to say that this system is sufficiently compatible with a data distribution service in a high-speed wireless environment capable of distributing a large amount of data such as video and audio data.

[0007]

By the way, data that is reproduced in time series, such as video and audio data, cannot be reproduced unless the entire data is received because of its characteristic. It is also possible to replay each time without accumulating the created data in the terminal (hereinafter, this technology is referred to as streaming technology). When delivering contents including data such as video and audio to portable information terminals, streaming techniques are often used.

However, there are cases where the user wants to store the content in the terminal, and there are cases where the content provider (source of the content) wants to store the content in the terminal. Therefore, not all contents are distributed using streaming technology, and it is desired to realize a storage-type content distribution service suitable for mobile information terminals.

Therefore, according to the present invention, due to the limitation of the memory capacity and the like, even when the data reproduced in chronological order such as the data of video and audio can be received only halfway, the data of the received portion can be In addition to guaranteeing playback, the data that was stored in the terminal and could only be received halfway is attached to mail, uploaded to the server, written to external memory, and then played on other terminals. In this case, the object of the present invention is to provide a data receiving device which guarantees the reproduction of the received data.

[0010]

The first aspect of the present invention is a data receiving device for receiving data conforming to a predetermined format, the data receiving device receiving the data, and the data receiving device receiving the data. Data storage means for storing the stored data and the data stored in the data storage means in a disconnected state when the data receiving means interrupts the reception of the data before receiving the entire data to be received. Data recovery means for recovering the data in a state conforming to a predetermined format. According to such a first invention,
The data restoration means restores data that could not be received halfway due to interruption of data reception to a state conforming to a predetermined format. As a result, it is possible to guarantee that the restored data can be processed correctly when processing the data that could only be received halfway. For example, even when data such as video and audio can be received only halfway, it can be guaranteed that the recovered data can be correctly reproduced by an arbitrary reproducing device.

According to a second aspect of the present invention, in the first aspect, the data receiving means interrupts the data reception when the data is received up to a preset limit size, and the data restoring means is the data receiving means. When the reception of data is interrupted, the data accumulated in the data accumulating means in the state of being cut in the limited size is restored to a state conforming to a predetermined format. According to such a second invention, the data receiving means receives the data only up to the limited size, and the data restoration means restores the data cut by the limited size to a state conforming to the predetermined format. This allows
It is possible to guarantee that the restored data can be correctly processed when processing the data that could not be received halfway because the size exceeds the limit size. For example, even when data such as video and audio can be received only partway due to exceeding the limit size, it is possible to guarantee that the recovered data can be correctly reproduced by an arbitrary reproducing device.

A third invention is characterized in that, in the second invention, the limit size is determined based on the remaining free space of the data storage means. According to the third aspect, a large amount of data can be received and stored by determining the limit size based on the amount of data that can be stored. For example, if the limit size is matched with the remaining free memory capacity of the terminal, the simple rule of changing the receivable data size according to the usage rate of the memory in the terminal is used, and the terminal as a whole has a high degree of freedom. To effectively utilize limited memory resources. In addition, all application software running on the terminal adopts a method of sharing the remaining free memory without setting an upper limit on the memory size that can be used by each software, so that the memory can be used with a high degree of freedom.

A fourth invention is characterized in that, in the second invention, the limit size is determined based on a characteristic of communication used by the data receiving means. According to the fourth aspect of the invention as described above, the limit size can be determined in consideration of the data transmission rate and the charge system unique to each communication line and communication method. For example, even if the communication line has the same transmission speed, if you use the time-charged communication line with the line connection type communication method, set a large value for the limit size and use the packet connection type communication method for each packet. When using a communication line whose transmission fee is high, a small value can be set for the limit size.

A fifth invention is characterized in that, in the second invention, the limit size is determined based on the type of data received by the data receiving means. According to the fifth aspect, the limit size can be determined in consideration of the tendency of the data amount that is determined for each type of data. For example, when the data amount of video data is larger than that of audio data, the limit size for obtaining video data can be set larger than the limit size for obtaining audio data.

A sixth invention is characterized in that, in the second invention, the limit size is determined based on a user's setting. According to the sixth aspect of the invention as described above, it is possible to set the reception size that is considered to be optimal, in accordance with the needs of the user and by considering the various conditions by the user himself.

In a seventh aspect based on the first aspect, the data includes one or more processing units that can be processed independently of each other, and the data receiving means receives the data in a data processing order. It is characterized by

The eighth invention is characterized in that, in the seventh invention, the data includes at least one of video data and audio data.

A ninth invention is characterized in that, in the eighth invention, the data is data in which video data and audio data are multiplexed in accordance with a predetermined format. According to the seventh to ninth aspects, since the data is received according to the processing order for each processing unit, even if the data receiving means interrupts the reception of the data for some reason, the data is received only halfway. By recovering the data that could not be received to a state conforming to the predetermined format, the data of the portion received before the interruption can be processed correctly. When the data is video or audio data, a typical example of the processing for these data is reproduction processing.

In a tenth aspect based on the seventh aspect, the data restoration means discards data of a portion less than a processing unit at a terminal portion of the data accumulated in the data accumulating means in a disconnected state. , A termination portion modification means for performing termination portion modification processing that leaves only processable data received before that portion. According to the tenth aspect, the data in the end portion of the data, which is less than the processing unit, is discarded, so that the data can be restored to the state conforming to the predetermined format.

The eleventh invention is the tenth invention, wherein
The data restoration unit further includes a restoration possibility determination unit that determines whether or not the data accumulated in the data accumulation unit in a disconnected state includes the minimum amount of data required for processing, and the terminal portion correction unit is In the case where it is judged by the repairability judging means that the correction is included, the end portion correction processing is performed. According to such an eleventh invention, when the minimum amount of data necessary for processing cannot be received, it is determined that the data cannot be repaired, and execution of unnecessary processing can be prevented. it can.

A twelfth invention is the eleventh invention, wherein
The data restoration means is characterized by discarding the data accumulated in the disconnected state in the data accumulation means when the restoration possibility judgment means judges that the data is not included.
According to the twelfth aspect, when the minimum amount of data necessary for processing cannot be received, it is determined that the data cannot be repaired, and the data is discarded. As a result, it is possible to prevent data that cannot be processed from being accumulated in the data receiving device, and it is possible to effectively utilize the storage circuit or storage device included in the device, such as the memory of the terminal.

A thirteenth invention is the same as the eleventh invention,
The data further includes additional information representing the attributes of the data,
The data restoration means further includes additional information updating means for updating the additional information included in the data after the end portion correction processing so as to represent the characteristics of the data. According to such a thirteenth aspect, by correctly updating the additional information indicating the attribute of the data, the data can be restored to the state conforming to the predetermined format.

A fourteenth invention is a data receiving method for receiving data conforming to a predetermined format, which comprises a data receiving step of receiving the data, and a data storing step of storing the data received in the data receiving step, Before receiving the entire data to be received, when the reception of the data in the data receiving step is interrupted, the data accumulated in the disconnected state by the data accumulating step,
A data restoration step of restoring the data to a state conforming to a predetermined format. According to the fourteenth aspect, the data restoration step restores the data that could not be received halfway due to the interruption of the data reception to the state conforming to the predetermined format. As a result, it is possible to guarantee that the restored data can be correctly processed when processing the data that cannot be received halfway. For example, even when data such as video and audio can be received only halfway, it can be guaranteed that the recovered data can be correctly reproduced by an arbitrary reproducing device.

The fifteenth invention is the fourteenth invention, wherein
The data receiving step interrupts the data reception when the data is received up to a preset limit size, and the data repairing step limits the data storage step when the data receiving step interrupts the data receiving step. The data accumulated in the disconnected state with
It is characterized by restoration to a state conforming to a predetermined format. According to such a fifteenth aspect, in the data receiving step, the data is received only up to the limit size, and in the data restoring step, the data cut by the limit size is restored to the state conforming to the predetermined format. As a result, it is possible to guarantee that the restored data can be correctly processed when processing the data that could only be received halfway because the size limit was exceeded. For example, even when data such as video and audio can be received only partway due to exceeding the limit size, it is possible to guarantee that the recovered data can be correctly reproduced by an arbitrary reproducing device.

A sixteenth invention is the fourteenth invention, wherein
The data includes one or more processing units that can be processed independently of each other, and the data receiving step is characterized in that the data is received according to a processing order of the data. According to the sixteenth aspect, since the data is received according to the processing order for each processing unit, even if the data reception is interrupted for some reason at the data reception step, the data can be received only halfway. By restoring the missing data to a state conforming to the predetermined format, the data of the portion received before the interruption can be processed correctly.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram showing an example of a data distribution system configuration for providing a service for distributing data such as video and audio. The system shown in FIG. 1 includes a mobile phone 101, a distribution server 102, a mobile phone network 103, the Internet 104, and a gateway 105.

The data receiving apparatus according to this embodiment is mounted on the mobile phone 101. The mobile phone 101 is connected to the mobile phone network 103. The distribution server 102 is connected to the Internet 104 and distributes data such as video and audio. The gateway 105 is the mobile phone network 1
Data is relayed between the network 03 and the Internet 104. The mobile phone 101 transmits the data such as video and audio transmitted from the distribution server 102 to the Internet 1
04, the gateway 105, and the mobile telephone network 103, and reproduces the received data.

Note that the system configuration shown in FIG. 1 is an example, and the device on which the data receiving apparatus of the present invention is mounted is not limited to the mobile phone 101, and may be any terminal, for example, equipped with a communication function. It may be a portable information device such as a PDA. Further, the network to which the terminals are connected is not limited to the mobile phone network 103, but PHS (Personal Handy pho
NeDA), wireless LAN (Local Area Network), Bluetooth (Bluetooth), and other networks using wireless technology, IrDA (InfraRed Data As
Sociation) and other networks using infrared rays may be used, and wired networks are not limited to wireless networks.
Further, the network to which the distribution server 102 is connected is
The intranet is not limited to the Internet 104, and may be an intranet including a gateway 105 and a dedicated line.

FIG. 2 is a block diagram showing the configuration of the data receiving apparatus according to this embodiment. The data receiving apparatus shown in FIG. 2 includes a data receiving unit 201, a data accumulating unit 202, a limit size storing unit 203, a reproducing unit 204, and a data restoring unit 205, and as described above, the mobile phone 101.
It will be implemented in any terminal, including. This data receiving device is characterized in that it restores data such as video and audio that could not be received halfway for some reason to a state conforming to a predetermined format.

Each component of the data receiving apparatus shown in FIG. 2 operates as follows. The data receiving unit 201 receives data such as video and audio distributed from the distribution server 102. The data distributed from the distribution server 102 conforms to a predetermined data format, as will be described later.

The data storage unit 202 is configured by a storage circuit such as a memory or a storage device, and the distribution server 10
The data such as video and audio distributed by the data receiving unit 201 is accumulated. The data storage unit 202 is composed of an arbitrary storage circuit or storage device having a data storage function. However, the effect of the present invention becomes remarkable when compared with the data distributed from the distribution server 102. This is the case when the capacity of the circuit or the storage device is not sufficient, for example, when the data storage unit 202 is configured by a memory. In this case, the data storage unit 202 may occupy a part of the memory built in the terminal, or may share the entire memory built in the terminal with other application software or the like. In the latter case, the data storage unit 202 also stores data other than the data such as video and audio distributed from the distribution server 102.

The limit size storage unit 203 stores the limit size (upper limit value) of the data stored in the data storage unit 202. The method for determining the limit size will be described later. The reproduction unit 204 reproduces the data such as video and audio stored in the data storage unit 202. Data restoration unit 20
Reference numeral 5 restores data such as video and audio that was stored in the data storage unit 202 only halfway because the size exceeds the limit size stored in the limit size storage unit 203 to a state conforming to a predetermined data format. . That is, the data restoration unit 205 restores the data stored in the data storage unit 202 in a state of being cut into a predetermined limit size to a state that complies with a predetermined data format.

FIG. 3 is a flow chart showing the processing contents in the data receiving apparatus shown in FIG. The flowchart shown in FIG. 3 shows the processing contents when one data is selected from a large number of data such as video and audio stored in the distribution server 102, received, and reproduced. Hereinafter, the limit size stored in the limit size storage unit 203 will be referred to as S _max, and the size of the data received by the data receiving unit 201 from the distribution server 102 after the start of data reception will be referred to as S _rcv .

The data receiving apparatus performs the processing from steps S301 to S304 as described below, and receives data such as video and audio from the distribution server 102. That is, in the process shown in FIG. 3, the data receiving unit 201 first receives the data distributed from the distribution server 102 (step S301). Next, the data receiving unit 2
01 determines whether or not the received data size S _rcv exceeds the limit size S _max (step S302). S _rcv
> S _max , that is, when the received data size S _rcv exceeds the limit size S _max (YES in step S302), the data receiving device is controlled in step S306.
Go to. If S _rcv ≦ S _max , that is, if the received data size S _rcv does not exceed the limit size S _max (NO in step S302), the control of the data receiving device proceeds to step S303.

In the latter case, the data receiving unit 201 writes the data received in step S301 in the data storage unit 202. Next, the data receiving unit 201 determines whether or not the data reception has been completed, that is, whether or not the entire data to be received has been received (step S304). When the data reception is completed (YES in step S304)
S), control of the data receiving device proceeds to step S305. If data reception has not been completed (step S
No of 304), the control of the data receiving device is step S3.
Go to 01. In this case, the data receiving device continues to receive data from the distribution server 102.

When the data reception is completed, the data receiving device reproduces the data stored in the data storage unit 202 (step S305). More specifically, the data receiving unit 201 notifies the reproducing unit 204 of the completion of the data reception, and the reproducing unit 204 which has received the notification of the data reception completion starts reproducing the data accumulated in the data accumulating unit 202. . When the reproduction of the data by the reproduction unit 204 is completed, the data reception device ends the reception and reproduction processing for one data.

S during data reception_rcv > S_max When
That is, the received data size S _rcv Is the limit size S
_max When it exceeds (YES in step S302),
The data receiving device performs step S30 as shown below.
The processing from 6 to step S309 is performed. That is,
The data receiving device firstly sets the limit size S._max Received up to
The accumulated data is accumulated (step S306). In more detail
Is received by the data receiving unit 201 in step S301.
Received data size S_rcv Is the limit size S_max 
Cut the data to match and store the cut data
Write in the section 202. Next, the data receiving device
Is interrupted (step S307). In more detail
Is the data received by the data receiving unit 201 from the distribution server 102.
Data reception is interrupted and the playback unit 204 receives data.
Notify the suspension of communication.

Next, the data receiving device restores the accumulated data (step S308). More specifically, when the reproduction unit 204 receives the data reception interruption notification from the data reception unit 201, it requests the data restoration unit 205 to restore the data stored in the data storage unit 202. Upon receiving the data restoration request, the data restoration unit 205 reads the data accumulated in the data accumulation unit 202, performs a restoration process on the read data, and writes the restored data in the data accumulation unit 202. Details of the data restoration process will be described later. When the data restoration process is completed, the data restoration unit 205 notifies the reproduction unit 204 of the data restoration completion.

When the process of step S308 is completed, the data receiving device reproduces the restored data (step S309). More specifically, when the reproducing unit 204 receives the data restoration completion notification, the reproducing unit 204 starts reproducing the restored data accumulated in the data accumulating unit 202. Playback part 2
When the reproduction of data by 04 is completed, the data receiving device ends the reception and reproduction processing for one data.

In the flow chart shown in FIG.
When the received data size S _rcv exceeds the limit size S _max , the data stored in the data storage unit 202 is restored. In addition to this, while receiving data from the distribution server 102 (that is, steps S301 to
(During execution of S304), reception of data before the reception data size S _rcv reaches the limit size S _max due to a reception cancellation operation by the user, disconnection of the line due to deterioration of the communication environment, malfunction of the distribution server side, or the like. Even if the processing was interrupted and the data could only be acquired halfway,
The data receiving unit 201 immediately notifies the reproducing unit 204 of interruption of data reception. In this case, control of the data receiving device proceeds to step S308, and the data receiving device
The accumulated data is restored (step S308), and the restored data is reproduced (step S309).

Further, in this embodiment, the reproducing section 204 is
When the reception completion notification is received from the data receiving unit 201, the data restoration unit 205 is requested to restore the data, and after the restoration completion notification is received from the data restoration unit 205, the restored data accumulated in the data accumulation unit 202 Decided to start playing. Instead of this, the data receiving unit 201
Requests the data restoration unit 205 to restore the data,
After receiving the restoration completion notification from the data restoration unit 205, the playback unit 204 may be requested to play back the restored data stored in the data storage unit 202.

The value of the limit size S _max stored in the limit size storage unit 203 is determined as follows. First, the limit size may be determined based on the remaining free storage capacity of the data storage unit 202, and more preferably, may be matched with the remaining free storage capacity of the data storage unit 202.
When the data storage unit 202 shares the entire memory built in the terminal (the mobile phone 101 in this embodiment) with other application software, the limit size is made to match the remaining free memory capacity of the terminal. May be.
When the limit size is matched with the remaining free memory capacity of the terminal, the memory can be used with a high degree of freedom as a whole terminal by simply following the simple rule of changing the size of data that can be received according to the usage rate of the memory in the terminal. However, the limited memory resources can be effectively utilized. For example, it is possible to use the memory with a high degree of freedom by adopting a method in which all the application software running on the terminal shares the remaining free memory without setting an upper limit on the memory size that can be used by each software.

Alternatively, the limit size is set to the data receiving unit 2
01 may be determined based on the characteristics of the communication used when 01 receives the data (type of communication line, communication method, etc.). As a result, it is possible to determine the limit size in consideration of the data transmission rate and the charge system unique to each communication line and communication method. For example, even if the communication line has the same transmission speed, if you use the time-charged communication line with the line connection type communication method, set a large value for the limit size and use the packet connection type communication method for each packet. When using a communication line whose transmission fee is high, a small value can be set for the limit size.

Alternatively, the limit size is set by the data receiving unit 2
It may be determined based on the type of data received in 01.
As a result, the limit size can be determined in consideration of the tendency of the amount of data determined for each type of data. For example, when the data amount of video data is larger than that of audio data, the limit size for obtaining video data can be set larger than the limit size for obtaining audio data.

Alternatively, the limit size may be determined based on the user's setting. As a result, it is possible to set the reception size that is considered to be optimal, in accordance with the needs of the user and by considering the various conditions by the user himself. Note that the user may select any one of the above-described limit size determination methods, instead of setting a value for the limit size.

Alternatively, the limit size may be determined by combining a plurality of the above limit size determination methods.

The details of the data restoration processing by the data restoration unit 205 will be described below. First, terms used in the following description will be defined. The “stream” refers to data that can be played back in chronological order when played back from the beginning, such as video and audio data. In the stream
In addition to video streams and audio streams, there are streams for control and streams whose usage is specified by applications. A "media file" is a file containing one or more streams, and one or more streams are multiplexed so that each stream can be played back in chronological order when played sequentially from the beginning of the file. . “Multiplex format” refers to the rules for the data structure of a media file.

In the distribution service of data such as video and audio, in general, not a stream of video or audio itself, but a media file in which a stream of video or audio is multiplexed according to a multiplexing format is distributed. Therefore, in the present embodiment, the data receiving unit 201 receives from the distribution server 102 and accumulates in the data accumulating unit 202.
The data such as video and audio that the data recovery processing target 5 performs is actually the above-mentioned media file.

"Multiplexing packet" is used to multiplex one or more streams included in a media file.
A stream is packetized by dividing it into a predetermined length. The format of the multiplexed packet is defined by the multiplexed format. A "playback unit" is a part of data extracted from each stream, and is independent of other data (that is, if the part of the data exists, the other data may be referred to without being referred to). ) Reproducible. For example, in the case of a video stream, the reproduction unit is data for one screen, and in the case of an audio stream, the reproduction unit is data for one sample, and the encoded video stream or the encoded audio stream is used. In the case of a stream, the reproduction unit is one frame of data that is the minimum unit for encoding. In addition, MPEG (Moving Pic)
ture Experts Group) and the like perform interframe predictive coding, and thus strictly speaking, predictively coded frames cannot be independently reproduced. However, in this embodiment,
Data is received in order from the beginning of the file, that is, the beginning of the stream. For this reason, it is assumed that the frame (I picture) that is the basis of prediction is always received in advance, and the predictively coded frame (P picture or B picture) is also treated as one reproduction unit.

The media file contains one or more multiplexed packets. One reproduction unit may be stored alone in one multiplexed packet, or may be divided and stored in a plurality of multiplexed packets. Also, a plurality of reproduction units may be stored in one multiplexed packet. An example of such a media file is MPE
There is a program stream defined by G.

When one or more streams are multiplexed to form a media file, the multiplexing may be performed hierarchically. For example, when focusing on a layer (lower layer) and a layer one layer above (upper layer) from a plurality of layers, when a lower layer multiplexed packet is stored alone in an upper layer multiplexed packet, It may be divided and stored in a plurality of upper layer multiplexed packets. Also, a plurality of lower layer multiplexed packets may be stored in one upper layer multiplexed packet. An example of such a media file is a transport stream defined by MPEG.

In the media file, in addition to the multiplexed packets, additional information indicating the content attributes such as the reproduction time of the entire media file and the number of multiplexed packets is added to the beginning of the file, the end of the file, or the middle of the file. May be included in.

FIG. 4 is a diagram showing an example of the structure of a media file. In FIG. 4, the media file 401
Includes additional information 402 of the media file and a plurality of multiplexed packets 403 to 405. Each of the multiplexed packets 403 to 405 includes video data of a reproduction unit (rectangle with V) and audio data of a reproduction unit (rectangle with A). FIG. 5 is a diagram showing the contents of the additional information 402 of the media file 401 shown in FIG. The additional information 402 includes the number of multiplexed packets and the reproduction time.

FIG. 6 is a flowchart of the data restoration processing by the data restoration unit 205. Data restoration unit 205
When receiving the data restoration request, reads out the media file that has been received only halfway from the data storage unit 202, performs the restoration process shown in FIG. 6, and writes the restored media file to the data storage unit 202. The data restoration unit 205 performs restoration possibility determination processing (step S601).
~ S602), end portion correction processing (step S603 ~)
S604) and additional information update processing (step S6)
The media file is restored to the state conforming to the multiplexing format by sequentially performing the three processes of 05). Media files repaired in this way
It can be played back by another playback device. Hereinafter, details of the three processes shown in FIG. 6 will be described.

First, a repairability determination process (step S60)
1 to S602) will be described. If the media file does not contain the minimum data required for playback,
It is meaningless even if it exists. Therefore, the data restoration unit 2
The 05 first checks whether or not the minimum data necessary for reproduction has been received (step S601). If such a minimum amount of data has not been received, the data restoration unit 205 determines that the data cannot be restored and discards the media file (step S606). For example, if none of the data corresponding to the reproduction unit has been received for each stream included in the media file, the received media file is discarded.

Next, the data restoration unit 205 checks whether or not the minimum amount of data necessary for constructing a media file conforming to the multiplexing format has been received (step S602). If such a minimum amount of data has not been received, the data restoration unit 205 determines that the restoration is impossible and discards the media file (step S).
606). For example, if no multiplexed packet has been received, the received media file is discarded. However, even if no multiplexed packet can be received, if the data for the playback unit can be received, the media file is not treated as unrepairable, and the multiplexed packet including the data for the playback unit is included. May be newly generated and restored to a media file containing the multiplexed packet.

FIG. 7 shows the media file 4 shown in FIG.
FIG. 15 is a diagram showing an example in which 01 is stored in the data storage unit 202 in an unrepairable state due to the limit size S _max stored in the limit size storage unit 203. In FIG. 7, a shaded portion 701 indicates a limit size storage unit 20.
The limit size S _max stored in No. 3 indicates the portion of the media file 401 actually stored in the data storage unit 202.

In this case, the additional information 402 and the multiplexed packet 403 of the media file 401 are stored in the data storage unit 202 only up to the middle. Since the acquisition of the first multiplexed packet has not been completed, and the video data of one reproduction unit in the multiplexed packet 403 has not been acquired, the data restoration unit 205 performs the restoration possibility determination process Judge that the media file cannot be repaired.

Next, the end portion correction process (step S60)
3 to S604) will be described. Data restoration unit 205
Discards the data less than the reproduction unit at the end of each stream included in the media file, and leaves only the data received before that in the repaired media file (step S603). Next, the data restoration unit 20
If there is a multiplexed packet containing data less than the reproduction unit, 5 converts the multiplexed packet into a multiplexed packet in which the data less than the reproduction unit is deleted (step S).
604).

Details of the multiplexed packet conversion processing in step S604 are as follows. If the multiplexed packet contains only data that is less than the reproduction unit, the multiplexed packet itself is deleted. When one multiplexed packet includes data of two or more reproduction units, only the last data that is less than the reproduction unit is deleted, and the multiplexed packet including other data is updated. When the data that does not meet the playback unit is divided and stored in multiple packets, the processing to delete or update the above multiplexed packets for all the multiplexed packets that contain the data that does not meet the playback unit I do. When hierarchical multiplexing is performed, the lowest layer multiplexing packet is updated first, and then the upper layer multiplexing packet is updated as necessary as the lower layer multiplexing packet is updated. Update.

It should be noted that, even if the reproducing apparatus for reproducing the media file restored by the data receiving apparatus inputs the media file containing the data less than the reproduction unit as long as the reproducing apparatus complies with the multiplexing format, no failure occurs. It may be guaranteed that (that is, not in an abnormal state). In such a case, the data restoration unit 205 checks the last received multiplexed packet without checking whether the media file has been received up to the reproduction unit, and determines that multiplexed packet in the middle of the multiplexed packet. The multiplexed packet may be deleted only when the packet has been received up to.

Next, additional information update processing (step S60)
5) will be described. In the additional information updating process, the data restoration unit 205 checks how far the file has been received, and restores the additional information included in the file as necessary. For example, when the additional information includes the playback time of the entire file, the data restoration unit 205 updates the value of the playback time in the additional information to match the shortened playback time of the restored media file. To do. Further, when the additional information includes the number of multiplexed packets included in the media file, the data restoration unit 205 reduces the value of the number of multiplexed packets included in the additional information to the lesser amount included in the restored media file. Update according to the number of multiplexed packets. In addition, in order to randomly access the media file, when the media file includes entry information indicating a randomly accessible reproduction start position, the data restoration unit 205 determines that the post-restoration is performed from the entry information in the additional information. Delete the playback start position that is not included in the media file.

As described above, the data restoration unit 205 performs the three processes of the restoration possibility determination process, the end portion correction process, and the additional information update process, so that the media file that has been partially received can be predetermined. Repair to a state that complies with the multiplex format of.

A specific example of the data restoration processing by the data restoration unit 205 will be described below. FIG. 8 is a diagram showing an example in which the media file shown in FIG. 4 is stored in the data storage unit 202 in a recoverable state by the limit size S _max recorded in the limit size storage unit 203. Figure 8
In FIG. 3, a shaded portion 801 indicates a portion of the media file 401 actually stored in the data storage unit 202 due to the limit size S _max stored in the limit size storage unit 203.

First, the data restoration unit 205 performs restoration possibility determination processing as the first processing. In the example shown in FIG. 8, the additional information 402, the multiplexing packet 403, and the middle of the multiplexing packet 404 of the media file 401 are accumulated in the data accumulating unit 202. Since the acquisition of the first multiplexed packet 403 has been completed, the data restoration unit 205 determines that the media file 401 can be restored.

Next, the data restoration unit 205 performs the end portion correction processing as the second processing. In this example, acquisition of the second multiplexed packet 404 has not been completed, and
The video data of one reproduction unit in the multiplexed packet 404 cannot be acquired. Therefore, the data restoration unit 205
Deletes the multiplexed packet 404 that can be acquired only halfway.

Finally, the data restoration unit 205 performs additional information update processing as the third processing. In this example, the data restoration unit 205 deletes the multiplexed packet 404,
The value set in the additional information 402 is updated.

FIG. 9 is a diagram showing the restored media file stored in the data storage unit 202 after the data restoration unit 205 performs the data restoration process on the media file shown in FIG. . In FIG. 9, the restored media file 901 includes additional information 902 and a multiplexing packet 403. The additional information 902 is additional information of the restored media file. The multiplexed packet 403 shown in FIG. 4 is included in the restored media file 901 as it is.

FIG. 10 is a diagram showing the contents of the additional information 902 of the media file 901 after the repair shown in FIG. In the additional information 902 shown in FIG. 10, compared with the additional information 402 before restoration shown in FIG. 5, the number of multiplexed packets and the value of the reproduction time are updated by the additional information update processing.

In this embodiment, the reproduction unit is the data for one frame of encoded video or audio, but instead of this, two or more frames are collectively processed as one reproduction unit. You may. This method is effective when a plurality of reproduction unit data are collectively stored as one unit in the multiplexed packet.

Further, in this embodiment, the data restoration unit 20
Reference numeral 5 denotes a repairability determination process, a terminal part correction process, and
Although the three processes of the additional information update process are performed, only the necessary process may be performed. For example, when there is no additional information in the media file, the additional information updating process may not be performed. Further, these processes may be performed in an order different from that of this embodiment.

As described above, the data receiving apparatus according to the present embodiment has the data receiving section for receiving data, the data storing section for storing the data received by the data receiving section, and the entire data to be received. Before receiving the data, when the data receiving unit interrupts the reception of the data, the data restoring unit restores the data accumulated in the data accumulating unit in the disconnected state to the state conforming to the predetermined format. Prepare As a result, it is possible to guarantee that the restored data can be processed correctly when processing the data that could only be received halfway. In the present embodiment, since data such as video and audio is received, it is possible to correctly reproduce the restored data with an arbitrary reproducing device even when the data such as video and audio can be received only halfway. Can be guaranteed.

Further, the data receiving section suspends the reception of the data when the data is received up to the preset limit size. As a result, it is possible to guarantee that the restored data can be correctly processed when processing the data that could only be received halfway because the size limit was exceeded. In the present embodiment, since data such as video and audio is received, even if the data such as video and audio can only be received halfway because the size exceeds the limit, after restoration by any playback device. It can be guaranteed that the data of can be correctly reproduced. Further, the limit size used for determining whether or not to interrupt the reception of data can be set to an appropriate value according to various factors.

In the above description, the case where the data reception is interrupted because the received data size exceeds the limit size has been mainly described, but the present invention is not limited to this, and for other reasons. Even when data reception is interrupted, the same effect as when the received data size exceeds the limit size can be obtained by performing the data restoration process shown in FIG.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a system configuration of a data distribution service in which a data receiving device according to an embodiment of the present invention is used.

FIG. 2 is a block diagram showing a configuration of a data receiving device according to an embodiment of the present invention.

FIG. 3 is a flowchart showing processing contents in the data receiving device according to the embodiment of the present invention.

FIG. 4 is a diagram showing an example of a configuration of a media file.

5 is a diagram showing the content of additional information of the media file shown in FIG.

FIG. 6 is a flowchart of a data restoration process in the data receiving device according to the embodiment of the present invention.

FIG. 7 is a diagram showing an example in which the media files shown in FIG. 4 are stored in an unrepairable state.

FIG. 8 is a diagram showing an example in which the media files shown in FIG. 4 are stored in a recoverable state.

9 is a diagram showing a media file after restoration after performing restoration processing on the media file shown in FIG. 8;

10 is a diagram showing the content of additional information of the media file after restoration shown in FIG.

[Explanation of symbols]

101 ... Mobile phone 102 ... Delivery server 103 ... Mobile phone network 104 ... Internet 105 ... Gateway 201 ... Data receiving unit 202 ... Data storage unit 203 ... Limit size storage unit 204 ... Playback unit 205 ... Data recovery unit 401 ... Media file 402 ... Additional information 403 to 405 ... Multiplexed packet 701, 801 ... Portion accumulated in the data accumulation unit 901 ... Media file after restoration 902 ... Additional information after restoration

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H04N 7/173 630 H04N 7/08 Z // H04N 5/76 (72) Inventor Makoto Hakai Kadoma City, Osaka Prefecture Daiji Kadoma 1006 Matsushita Electric Industrial Co., Ltd. F term (reference) 5C052 AA01 AA16 AB04 CC01 DD04 5C063 AB03 AB05 AC01 AC05 AC10 CA23 CA36 DA05 DA07 DB10 5C064 BA07 BB05 BC18 BC23 BC25 BD02 BD03 BD08 BD09 BD13 5K014 A0601K01 A06K101 A0301 LL12 MM07 NN06 NN07 NN21

Claims (16)

[Claims] 1. A data receiving device for receiving data conforming to a predetermined format, comprising: a data receiving means for receiving the data; a data accumulating means for accumulating the data received by the data receiving means; Before the entire data to be received is received, when the data receiving means interrupts the reception of the data, the data accumulated in the data accumulating means in the disconnected state is in a state conforming to the predetermined format. A data receiving device, comprising: 2. The data receiving means interrupts data reception when the data is received up to a preset limit size, and the data restoring means interrupts data reception by the data receiving means. The data receiving apparatus according to claim 1, characterized in that the data accumulated in the data accumulating means in a state of being cut in the limited size is restored to a state conforming to the predetermined format. . 3. The limit size is determined based on the remaining free space of the data storage means,
The data receiving device according to claim 2. 4. The data receiving apparatus according to claim 2, wherein the limit size is determined based on a characteristic of communication used by the data receiving unit. 5. The data receiving apparatus according to claim 2, wherein the limit size is determined based on a type of data received by the data receiving unit. 6. The data receiving apparatus according to claim 2, wherein the limit size is determined based on a user setting. 7. The data includes one or more processing units that can be processed independently of each other, and the data receiving unit receives the data according to a processing order of the data. The data receiving device according to claim 1. 8. The data receiving apparatus according to claim 7, wherein the data includes at least one of video data and audio data. 9. The data receiving apparatus according to claim 8, wherein the data is data in which video data and audio data are multiplexed according to the predetermined format. 10. The data restoration means discards data of a portion less than a processing unit at a terminal portion of data accumulated in the data accumulation means in a disconnected state,
8. The data receiving apparatus according to claim 7, further comprising an end portion correction unit that performs an end portion correction process for leaving only processable data received before the portion. 11. The data restoration means further comprises restoration possibility determination means for determining whether or not the data accumulated in the data accumulation means in a disconnected state includes the minimum data required for processing. 11. The data receiving apparatus according to claim 10, wherein the end portion correction means performs the end portion correction processing when the repairability determination means determines that the repair is included. 12. The data restoration means discards the data accumulated in the disconnected state in the data accumulation means when the restoration possibility judgment means judges that the data is not included. The data receiving device according to claim 11. 13. The data further includes additional information indicating an attribute of the data, and the data restoration unit expresses a characteristic of the data regarding the data after the end portion correction processing,
The data receiving device according to claim 11, further comprising additional information updating means for updating the additional information included in the data. 14. A data receiving method for receiving data conforming to a predetermined format, comprising: a data receiving step of receiving the data; a data storing step of storing the data received in the data receiving step; Before receiving the entire data to be processed, when the reception of the data in the data receiving step is interrupted, the data accumulated in the disconnected state by the data accumulating step is converted into a state conforming to the predetermined format. A method for receiving data, comprising a step of recovering data. 15. The data receiving step interrupts data reception when the data is received up to a preset limit size, and the data restoring step interrupts data reception in the data receiving step. 15. The data receiving method according to claim 14, wherein the data stored in the state of being cut in the limited size by the data storing step is restored to a state conforming to the predetermined format. . 16. The data includes one or more processing units that can be processed independently of each other, and the data receiving step receives the data according to a processing order of the data. The data receiving method according to claim 14.