JP2003333489A - Device and method for reproducing data - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for reproducing data and a method for the same in which, when a terminal related only to a basic portion of a file receives the file with an extended portion, the terminal receives and reproduces only the basic portion in the file. <P>SOLUTION: A reception means Recpt receives the file, and an analysis means Search determines if the file includes the extended portion, referring to an identifier added to the file. If the file includes the extended portion, an operation control means Ctrl controls the reception means Recpt to receive only data corresponding to the basic portion. A demultiplexing means Demux demultiplexes the data of the basic portion, and a decoding means Dec decodes the damultiplexed data, and a display means Play reproduces and displays the decoded data. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reproducing apparatus for downloading and reproducing a moving image data file on a remote server through a wired or wireless network.

[0002]

2. Description of the Related Art In recent years, a moving image distribution service for PCs on the Internet has become widespread due to an increase in capacity of communication networks and advances in transmission technology. Furthermore, regarding video distribution on wireless terminals, 3GPP (Third Generatio) is an international standardization organization that defines the standards for receiving terminals in wireless networks.
n Partnership Project) standard TS26.234 (T
ransparent end-to-end packet switched streaming se
rvice) has been established, and video distribution is expected to spread even on mobile terminals. There are two types of video distribution services, streaming type and download type. In the streaming type, the media data is directly delivered from the server, and the receiving side plays back the delivered media data in real time. Here, the media data refers to data such as audio, video, text, or a still image. In the download type, a file storing media data is distributed, and the receiving side plays the media data while downloading the file or after the download is completed. The method of playing while downloading is called pseudo streaming, and it is effective in shortening the waiting time until the start of playing when the file size is large. Comparing streaming type and download type, streaming type is suitable for live distribution and long-time content distribution, but servers supporting streaming type distribution are not popular or packet loss occurs frequently depending on network conditions. It is not popular because of the problem that it does, and the current video distribution service is mainly download type. The downloaded file contains header information and media data necessary for playing the media data, and the multiplexed file format is ISO / IEC JTC1 / SC29 / WG 11 (Int
ernational Standardisation Organization / Internation
MP4 was standardized in the al Engineering Consortium). MP4 is also adopted in TS26.234 of 3GPP,
It is expected that video distribution services using MP4 will spread in the future.

Here, the data structure of MP4 will be described. In MP4, header information and media data are stored in object units called Box. FIG. 8 is a diagram for explaining the structure of the Box. Box has the following fields. size: Size of the entire Box including the size field type: Box identifier, which is usually represented by four alphabets version: Box version number flags: Flag information data set for each box: Header information and media Data is stored.

However, since version and flags are not essential, these fields do not exist in some Boxes.
Hereinafter, the identifier of the type field will be used to refer to the Box. For example, a Box whose type is'moov 'is called moov. MP4 files can use extension parts in addition to the essential parts that must be used. The extension is currently being standardized. First, the structure of the basic part will be described. FIG. 9 is a diagram for explaining the basic part of an MP4 file. MP4 files are ftyp, moov, mdat
It consists of 3 basic boxes, and ftyp is placed at the beginning of the file. Media data is stored in mdat in units called samples. A sample is the smallest unit for handling media data in MP4, and corresponds to an audio frame or VOP (Video Object Plane) of MPEG-4 Visual. Moov stores the header information of the sample included in mdat. FIG. 10 is a diagram for explaining the structure of moov. In moov, Boxes are hierarchically arranged, header information is divided for each media such as audio and video in the upper Box, and header information for each sample is stored in the lower Box. In Figure 11, MP4
The hierarchical structure of Box in the basic part of the file is shown. Three boxes of ftyp, moov, and mdat are arranged in the highest hierarchy, and indispensable Boxes called mvhd and trak, and mvex are arranged immediately below moov. Here, mvex is a Box for indicating that the MP4 file includes an extension, and is used only when the MP4 file includes the extension. Each Box has a structure that does not depend on the type of media data or encoding format, and the media data to be stored in MP4 and the encoding format of the media data can be specified independently by standardization organizations and service providers. Which standard the MP4 file conforms to is specified by ftyp. FIG. 12 is a diagram for explaining the structure of ftyp. The ftyp contains the following information. major-brand: The identification name (brand) of the specification most suitable for playing an MP4 file minor-version: The version number of major-brand compatible-brands: The identification name (brand) of the specification compatible with major-brand

For example, an MP4 file of 3GPP specifications is '3gp4'
It is identified by a brand name such as or '3gp5'. '3gp5'
In brand MP4, in addition to audio and video encoding formats handled by '3gp4', text data based on 3GPP's own text format standardized in TS26.234 can be stored.

Next, the structure of the expansion portion will be described with reference to FIG. The divided header information is stored in each moof, and mdat is added to the moof. In addition, ftyp and moov are indispensable when using the extension part, and header information common to the entire media data such as the encoding format is stored in moov. FIG. 14 is a diagram for explaining a usage example of the extension unit. Here, about the storage method of contents, 2
Here is an example of the street. It is assumed that the reproduction time of the content is 60 seconds. MP4 file 1 stores media data using both the basic part and the extension part. The content is divided into three parts, 0-30 seconds, 30-45 seconds and 45-60 seconds. Is the basic part
It is stored in mdat1, and the parts of and are stored in mdat2 and mdat3, respectively, using the extension part. The layout of Box of the extension part is in the order of moof1, mdat2, moof2, mdat3,
The header information of mdat2 is in moof1 and the header information of mdat3 is moo.
indicated by f2. The MP4 file 2 stores media data using only the extension part. The content is divided into two parts, 0-30 seconds and 30-60 seconds,
They are stored in mdat4 and mdat5, respectively. The layout of Box of the extension part is in the order of moof3, mdat4, moof4, mdat5,
The header information of mdat4 is in moof3, and the header information of mdat5 is moo.
Represented by f4. The basic part contains only ftyp and moov, not mdat.

A conventional example will be described below. Figure 15
[Fig. 6] is a diagram for explaining a method of downloading and reproducing an MP4 file. Where the content is news.m
It is an MP4 file called p4, and only the basic part is used to store content data. The data playback device
Use the HTTP (HyperText Transfer Protocol) GET method to request a new.mp4 file on the site contents.net. The data transmission device transmits a response message indicating that the acquisition request has been successfully processed, and then transmits the news.mp4 file. The data reproducing device reproduces the content data while receiving the news.mp4 file or after the reception. FIG. 16 is a block diagram of a conventional data reproducing device. Data receiving means Re
cpt receives the file data Fdat1 and inputs it to the memory Mem as temporary storage file data Fdat2. Memory Mem
Inputs the input temporary storage file data Fdat2 as reproduction file data Fdat3 to the demultiplexing means Demux. Demultiplexing means Demux playback file data Fdat3
Is input during the reception of the file data Fdat1 by the reception means Recpt or after the reception is completed. Demultiplexing means
The Demux demultiplexes the reproduction file data Fdat3 to obtain the media data Str, and inputs it to the decoding means Dec. The display means Dec inputs the reproduction signal DatOut to the display means Play after decoding the media data Str, and the display means Play reproduces the reproduction signal DatOut.
Is displayed. When storing received files,
m is the file data Fdat1 for storing file data StorIn
Is input to the storage means Stor, and the storage means Stor stores the storage file data StorIn.

[0008]

A download service using an MP4 file consisting of a basic part has already been put to practical use, but a conventional terminal that does not support the extension part received an MP4 file containing the extension part. There are the following issues. The first problem is that, in the conventional terminal, the receivable basic part cannot be actually reproduced because the receivable file is limited by the ftyp brand information and the file size. A second problem is that the conventional terminal cannot interpret the structure of the extension part, so that the extension part that cannot be reproduced on the terminal is also downloaded. A third problem is that it is necessary to create two types of contents for a conventional terminal and a terminal that can also reproduce the extension when creating the content.

[0009]

In order to solve the above-mentioned problems, in the data reproducing apparatus and the data reproducing method of the present invention, it is determined whether the MP4 file to be received includes the extension part, and when the extension part is included. Is for receiving and reproducing only the basic part, and is configured by the following means.

The data reproducing apparatus according to claim 1 of the present invention refers to the receiving means for receiving the file of the moving image data and the identifier given to the file, and whether the whole file can be reproduced or not. And a control means for controlling the reception and reproduction of the file until a predetermined condition is reached when it is determined that the entire file cannot be reproduced by the judgment means.
A decoding unit that decodes the moving image data included in the file, and a display unit that reproduces and displays the decoded data are provided.

According to a second aspect of the present invention, in the data reproducing apparatus according to the first aspect, when the control means cannot reproduce the entire file, a message indicating to the display means that the entire file cannot be reproduced. It is characterized by instructing to display.

According to a third aspect of the present invention, in the data reproducing apparatus according to the first aspect, when the entire file cannot be reproduced, the control section gives a voice message to the display means indicating that the entire file cannot be reproduced. It is characterized by instructing as shown.

According to a fourth aspect of the present invention, in the data reproducing apparatus according to the first aspect, the file includes a basic part and an extension part, and the basic part includes one header part and a moving image data storage part. The expansion unit is characterized by having at least one packet including a header unit and a moving image data storage unit.

A data reproducing apparatus according to a fifth aspect of the present invention is characterized in that the predetermined condition in the first aspect is whether or not the amount of received data reaches a certain value. is there.

A data reproducing apparatus according to a sixth aspect of the present invention is characterized in that the predetermined condition in the first aspect is that the reception of the extended portion of the file is started. is there.

According to a seventh aspect of the present invention, the data reproducing device can reproduce the entire file by referring to the receiving means for receiving the file of the moving image data and the identifier given to the file. Included in the file is a determination means for determining whether or not the file, and a control means for controlling the storage of the file until a predetermined condition is reached when the determination means determines that the entire file cannot be reproduced. A decoding means for decoding the moving image data, a display means for reproducing and displaying the decoded data,
Means for accumulating the file.

Further, in the data reproducing method according to the eighth aspect of the present invention, the entire file can be reproduced by referring to the receiving step of receiving the file of the moving image data and the identifier given to the file. A determination step for determining whether or not the entire file cannot be reproduced by the determination means, a control step for controlling the file to be received and reproduced until a predetermined condition is reached, and the file A decoding step of decoding the moving image data included in, and reproducing the decoded data,
And a display step for displaying.

[0018]

(First Embodiment) A first embodiment of the data reproducing apparatus of the present invention will be described with reference to FIGS.

FIG. 1 is a block diagram showing the structure of the data reproducing apparatus. Data receiving means Recpt is file data F
dat1 is received and input to the memory Mem as temporary storage file data Fdat2. The memory Mem inputs the input temporary storage file data Fdat2 as the reproduction file data Fdat3 to the analysis determination means Search and the demultiplexing means Demux. The analysis determination means Search determines whether or not the received file includes an extension, and inputs the file analysis result Finf to the operation control means Ctrl. Figure 2 shows the file analysis result Finf
It is a figure for explaining the contents of. When the extension part is included, the information indicating that the extension part is included is included, as well as the information indicating the size of the basic part or the information for identifying the start of the extension part. If the extension is not included, information indicating that the extension is not included is included. The operation control means Ctrl controls the operations of the reception means Recpt, the demultiplexing means Demux, and the display means Play according to the contents of the file analysis result Finf. The demultiplexing unit Demux demultiplexes the reproduction file data Fdat3 to obtain the media data Str, and inputs it to the decoding unit Dec. Decryption means De
The c inputs the reproduction signal DatOut to the display means Play after decoding the media data Str, and the display means Play displays the reproduction signal DatOut.

FIG. 3 is a flow chart for explaining the operation of the data reproducing device when an MP4 file is received by HTTP. In Step 101, the data receiving means Recpt receives ftyp, moov, and mdat included in the basic part. With regard to mdat, it is not necessary to receive all of them, as long as reception of the size field is completed. Step
At 102, the analysis determination unit Search analyzes ftyp and moov, and if moov includes mvex, it determines that the MP4 file includes an extension. For the judgment, ftyp
You may use major-brand or minor-version of.
For example, if major-brand is'xxx0 ', only the basic part,' xxx
If 1'is specified to include an extension, major-
Since the brand is'xxx1 ', it is determined that the extension part is included. The same applies when referring to compatible-brand. If the major-brand is'xyxy 'and the minor-version is 0, it is specified that only the basic part is included, and if the major-brand is 1, the expanded part is included. Is determined to include. Note that'xxx0 ',' xxx1 'and'xyxy' are
This is an example for explaining the method of determination by ftyp, and the actual brand name is specified for each service. If the file size exceeds a predetermined value, it may be determined that the extension part is included. For example, if the predetermined value is 500 kB and the size of the file is 500 kB or more, it is determined that the extension part is included. The file size is Co of HTTP header.
Obtain from the ntent-Length field. After the determination, the file analysis result Finf including the determination result and the file information is input to the operation control means Ctrl. The file analysis result
Finf may be input only when the extension is included. The contents of the file analysis result Finf are as described with reference to FIG. 2. In the case of an MP4 file, ftyp, moov, and the mdat size of the basic part are separately shown as information indicating the size of the basic part. May be 3
It may indicate the total size of one Box. Note that the type field is'moof 'to identify the start of the extension.
The file analysis result Finf may include information indicating that the Box is an expanded Box.

Next, when it is judged in Step 102 that the extension part is included, in Step 103 the operation control means Ctrl
Controls the operation of each means. Fig. 4 shows the operation control means Ctrl
5 is a flowchart for explaining the operation of FIG.
In Step 104, receiving means Recpt, demultiplexing means Demu
Of x and display means Play, means for controlling the operation is determined. At this time, the operations of all three means may be controlled, or only specific means may be controlled. The receiving unit Recpt, the demultiplexing unit Demux, and the display unit Play are controlled by outputting Ctrl1, Ctrl2, and Ctrl3, respectively.

When controlling the receiving operation, in step 105, the receiving means Recpt is controlled so as to end the reception of the file after the reception of the basic part. At this time, the size of the basic part is acquired from the file analysis result Finf, and when the data for the size of the basic part is received, the reception is ended. Note that type
The box whose field is'moof 'is indicated by the file analysis result Finf that it is the Box of the extension part, or when it is set in advance, the reception may be terminated when the moof is received. In addition, due to the service or terminal memory capacity restrictions, an upper limit is set for the file size when receiving MP4 files.
If the size of the received file indicated in the t-length field exceeds the upper limit value, it is considered that the file is not received. However, in MP4 including the extension part, the size of the basic part may be less than or equal to the upper limit value even if the size of the entire file exceeds the upper limit value. Therefore, reception may be started even if the value of the Content-length field exceeds the upper limit, and reception may be stopped if the size of the basic part exceeds the upper limit. In addition, only when it is possible to determine that the MP4 file uses the extension part from the WEB page for downloading the MP4 file or the extension of the MP4 file, do not refer to the value in the Content-length field for reception. May be

When controlling the reproducing operation, in step 106, the demultiplexing means Demux is controlled so that only the media data of the basic part is demultiplexed and reproduced. In MP4 files, only samples that can be demultiplexed by referring to moov are played. When controlling the receiving means to receive only the data of the basic part, the file data for reproduction Fdat3 contains only the data of the basic part, so that the demultiplexing means De
The mux does not have to be controlled.

When controlling the display operation, in step 107, the display means Play is controlled so as to display a warning message indicating that all the media data stored in the MP4 file cannot be reproduced. The warning message may be displayed before the reproduction of the basic part is started, or may be displayed after the reproduction of the basic part is completed. A message indicating that the MP4 file including the extension part is not reproduced may be displayed. FIG. 5 shows a display example of a warning message on a mobile phone that does not support reproduction of the extension. In (1), after notifying that only a part of the received file can be reproduced, the basic part is reproduced when the user instructs the reproduction start. (2) indicates that the MP4 file including the extension is not reproduced. The warning message may be transmitted by voice.

(Second Embodiment) In the data reproducing apparatus of the first embodiment, the received file is not stored, but in the data reproducing apparatus of the second embodiment, the data of the received file is stored. accumulate.

FIG. 6 is a block diagram of a data reproducing apparatus according to the second embodiment of the present invention. The data receiving means Recpt receives the file data Fdat1 and temporarily stores the file data Fdat.
Input it to memory Mem as dat2. The memory Mem inputs the input temporary storage file data Fdat2 as the reproduction file data Fdat3 to the analysis determination unit Search and the demultiplexing unit Demux, and inputs the storage file data StorIn to the storage unit Stor. The storage unit Stor stores the storage file data StorIn. The analysis determination means Search determines whether or not the received file includes an extension, and inputs the file analysis result Finf to the operation control means Ctrl. The contents of the file analysis result Finf are the same as in the first embodiment. The operation control means Ctrl is the file analysis result Finf
Depending on the contents of the receiving means Recpt, demultiplexing means Demux,
It controls the operations of the display unit Play and the storage unit Stor.
The demultiplexing unit Demux demultiplexes the reproduction file data Fdat3 to obtain the media data Str, and inputs it to the decoding unit Dec. The decoding means Dec inputs the reproduction signal DatOut to the display means Play after decoding the media data Str, and the display means Play
Displays the playback signal DatOut.

When controlling the accumulation operation, the operation control means Ct
rl outputs the operation control signal Ctrl4 and controls the storage means Stor so as to store only the data of the basic part. This allows
Only the reproducible part of the terminal can be stored. In addition, when the upper limit of the storable size is set for the MP4 file including the basic portion, the accumulation is performed only when the size of the basic portion is equal to or smaller than the upper limit value. When controlling the receiving means to receive only the data of the basic part, since the file data for storage StorIn includes only the data of the basic part, it is not necessary to control the storage operation.

(Third Embodiment) In the first and second embodiments, the MP4 file on the remote server is downloaded. In the data reproducing device according to the third embodiment, the MP4 file accumulated in advance is reproduced.

FIG. 7 is a block diagram of a data reproducing apparatus according to the third embodiment of the present invention. The storage unit Stor inputs the read file data StorOut to the memory Mem. In addition,
The storage unit Stor may be a storage device incorporated in the data reproducing device, or may be a removable storage device such as an SD card. The memory Mem inputs the input read file data StorOut as the reproduction file data Fdat3 to the analysis determination means Search and the demultiplexing means Demux. The analysis determination unit Search determines whether or not the read file includes the extension part, and inputs the file analysis result Finf to the operation control unit Ctrl. File analysis result Finf
The contents of are the same as those in the first embodiment. The operation control means Ctrl uses the demultiplexing means Demu according to the contents of Finf.
x, controlling the operation of the display means Play. Demux means Demux
Demultiplexes the reproduction file data Fdat3 to obtain the media data Str, and inputs it to the decoding means Dec. Decoding means
Dec indicates that the reproduction signal DatOut is input to the display unit Play after the media data Str is decoded, and the display unit Play reproduces the reproduction signal DatOut.
Is displayed.

[0030]

According to the data reproducing apparatus of the first embodiment of the present invention, when the file to be received includes the extension portion, the basic portion is received and reproduced, so that even when the file including the extension portion is received. It is possible to reproduce the data of the basic part.

According to the data reproducing apparatus according to the second embodiment of the present invention, when the received MP4 file includes the extension part, only the basic part is accumulated, so that only the data that can be reproduced by the terminal is accumulated. Is possible.

According to the data reproducing apparatus according to the third embodiment of the present invention, even when the accumulated file is reproduced, it is judged whether or not the file includes the extension portion and the reproduction is performed. Also makes it possible to reproduce the data of the basic part.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a data reproducing device according to a first embodiment of the present invention.

FIG. 2 is a diagram for explaining a file analysis result Finf.

FIG. 3 is a flowchart showing the operation of the data reproducing apparatus of the present invention.

FIG. 4 is a flowchart showing the operation of the operation control means Ctrl.

FIG. 5 is a diagram for explaining an example of a warning message when the entire file cannot be played.

FIG. 6 is a block diagram showing a configuration of a data reproducing device according to a second embodiment of the present invention.

FIG. 7 is a block diagram showing a configuration of a data reproducing device according to a third embodiment of the present invention.

FIG. 8 is a diagram for explaining the MP4 Box structure.

FIG. 9 is a diagram for explaining the structure of the basic part of an MP4 file.

FIG. 10 is a diagram for explaining the structure of moov.

FIG. 11 is a diagram for explaining the hierarchical structure of Box in an MP4 file.

FIG. 12 is a diagram for explaining the structure of ftyp.

FIG. 13 is a diagram for explaining the structure of the extension part of the MP4 file.

FIG. 14 is a diagram for explaining an example of content storage using an extension unit.

FIG. 15 is a diagram for explaining a method of downloading an MP4 file.

FIG. 16 is a block diagram showing the configuration of a conventional data reproducing device.

[Explanation of symbols] Recpt data receiving means Mem memory Demux Demultiplexing means Dec decryption method Play display means Stor storage means Search Analysis judgment means Ctrl operation control means Fdat1 file data Fdat2 temporary save file data Fdat3 playback file data Ctrl1, Ctrl2, Ctrl3, ctrl4 operation control signal Str media data DatOut playback signal File data for StorIn storage StorOut read file data

Continued front page    (72) Inventor Yoji Notoya             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F-term (reference) 5C052 AA17 AB09 AC00 CC01                 5C053 FA27 GB06 GB37 HA40 JA21                       KA01 KA24 LA14

Claims (9)

[Claims] 1. A receiving means for receiving a file of moving image data, a judging means for judging whether or not the entire file can be reproduced by referring to an identifier given to the file, and the judging means. When it is determined that the entire file cannot be reproduced, the control unit receives the file until a predetermined condition is reached and controls to reproduce the file, and a decoding unit that decodes the moving image data included in the file, A data reproducing apparatus, comprising: a display unit that reproduces and displays the decrypted data. 2. The control means, when the entire file cannot be reproduced, instructs the display means to display a message indicating that the entire file cannot be reproduced. The described data reproducing device. 3. The control means, when the entire file cannot be reproduced, instructs the display means to indicate by voice that the entire file cannot be reproduced. Data playback device. 4. The file is composed of a basic part and an extension part, the basic part is composed of one header part and a moving image data storage part, and the expansion part is composed of a header part and a moving image data storage part. The data reproducing apparatus according to claim 1, wherein the data reproducing apparatus has at least one packet. 5. The data reproducing apparatus according to claim 1, wherein the predetermined condition is whether or not the amount of received data has reached a certain value. 6. The data reproducing apparatus according to claim 4, wherein the predetermined condition is that the reception of the extended portion of the file is started. 7. A receiving unit for receiving a file of moving image data, a judging unit for judging whether or not the entire file can be reproduced by referring to an identifier given to the file, and the judging unit. When it is determined that the entire file cannot be reproduced, a control unit that controls to store the file until a predetermined condition is reached, a decoding unit that decodes moving image data included in the file, and the decoding unit A data reproducing device comprising: a display unit for reproducing and displaying data; and a unit for accumulating the file. 8. A receiving step of receiving a file of moving image data, a judging step of judging whether or not the entire file is reproducible by referring to an identifier given to the file, and the judging means. When it is determined that the entire file cannot be played back, the file is received until a predetermined condition is reached, a control step of controlling the file to be played back, and a decoding step of decoding the moving image data included in the file, A reproducing step of reproducing and displaying the decrypted data, and a data reproducing method comprising: 9. A receiving step of receiving a file of moving image data, a judging step of judging whether or not the entire file is reproducible by referring to an identifier given to the file, and the judging means. When it is determined that the entire file cannot be played back, the file is received until a predetermined condition is reached, a control step of controlling the file to be played back, and a decoding step of decoding the moving image data included in the file, A recording medium storing a program including a display step of reproducing and displaying the decrypted data.