JP2003209593A - Storage type and streaming-combined data transmission method, transmission system, delivery device, and transmission program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a data transmission method capable of streaming high- quality data at middle frequency band or low frequency band, or the like receiving no influence of a frequency band shift relative to data transmission, in which the frequency band is shifted along a time axis, a transmission system, a delivery device, and a transmission program. <P>SOLUTION: In the data transmission in which the frequency band is shifted along the time axis, data deviated from a frequency band usable for the data transmission in a transmission line are precedently transmitted at the time of showing low data volume. The preceded data are stored at a transmission destination. The preceded data are re-composited with data successively transmitted to the transmission destination and data forming paired data with respect to the preceded data and is reproduced. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a storage type and streaming combined data transmission method, a transmission system, a distribution device and a transmission program.

[0002]

2. Description of the Related Art Conventionally, as a mode of transmitting data, packet communication has been performed in which data is divided into small single units called packets and the data is transmitted in packet units. There are various types of data such as voices, still images, and movies, and the amount of data handled varies depending on these types, so the time required to download various types of data via the Internet is also the amount of data. It will increase with the increase of. Especially for videos,
Even if you want to download the video data and play it on your own terminal immediately because the amount of data is very large,
It takes a considerable waiting time to start this playback. Recently, streaming technology has been developed, in which downloading and playback are performed in parallel without completely downloading all data, that is, playback is performed from a portion of the data that has been downloaded. Time has come to be shortened.

[0003]

However, even with such a technique, it is essential to satisfy some conditions in order to transmit and reproduce data with high quality. For example, when using a fixed bit rate for transmitting while keeping the band fixed as one of the data transmission methods, it is essential to secure the maximum band in the transmission line for data whose band changes along the time axis. If it cannot be secured, data loss occurs and reproduction cannot be performed at the transmission destination, or the quality of data must be reduced to a band that can be secured in the transmission path. Recently, the amount of data to be handled has increased along with the dramatic improvement in machine specifications and the multifunctionalization of software, and this is a serious problem especially for moving images. Since it is usually difficult to secure the maximum bandwidth, a method using a variable bit rate for varying the bandwidth for transmission is also used. For example, ADSL (Asymmetric Digital)
Packet loss is likely to occur on a transmission line whose bandwidth changes drastically depending on usage conditions such as Subscriber Line), and the playback speed of videos may vary, or even when dropped frames may not be played. .

Therefore, the present invention relates to the transmission of data whose band varies along the time axis, and a data transmission method which enables high-quality data streaming in a medium band or a low band which is not affected by the band change. An object is to provide a transmission system, a distribution device, and a transmission program.

[0005]

The present invention is configured as follows to solve the above problems. That is, according to one aspect of the present invention, there is provided a transmission method between a transmitter and a receiver of a data group having a reproduction order and a data band of a unit data group to be transmitted per unit time in a time series order, wherein A band is compared with a transmission band that can be used in a transmission path for transmitting the data group, and the comparison is performed to extract data in which a transmission loss is predicted in the unit data group or data corresponding to the data belonging to the unit data group. Then, the extracted data is applied to a data structure group that does not reach the transmission band, which is transmitted prior to the unit data group in which the extraction is performed, so as not to exceed the transmission band, and is established as described above. The transmitted data group is transmitted on the transmission line, the data allocated to the transmitted data group is detected, the detected data is accumulated, and the accumulated data is transmitted later. The unit data group paired with the data is reconstructed, and the reconstructed unit data group is reproduced at an arbitrary time point.

In this way, even in transmission data that exceeds the transmission band, data that exceeds this band is not discarded, and data is not compressed so as not to exceed the band,
All data can be placed on the transmission line. In addition, since the data that exceeds the band transmitted in advance is stored at the transmission destination, the data can be reproduced at any time as soon as the pair of data arrives.

According to another aspect of the present invention, there is provided a transmission system which handles a data group having a reproduction order and in which a data band of a unit data group to be transmitted per unit time in a time series order is not constant. Comparing means for comparing the data band with a transmission band that can be used in a transmission path for transmitting the data group, data for which transmission loss is predicted in the unit data group by the comparison, or the data corresponding to the unit data group Means for extracting the data, and the extracted data is applied to a data structure group that is transmitted prior to the unit data group from which the extraction is performed and does not exceed the transmission band. Allocation means, transmission means for transmitting the data group established as described above on the transmission path, and detection means for detecting the data allocated to the transmitted data group. If, means for storing the data the detected, a reconstruction means is transmitted and after the accumulated data to reconstruct a unit data group formed on the data pair,
And a reproducing means for reproducing the reconstructed unit data group at an arbitrary time point.

According to this structure, even in the transmission data exceeding the transmission band, all the data is transmitted without discarding the data exceeding this band or compressing the data so as not to exceed the band. Can be placed on the road. In addition, since the data that exceeds the band transmitted in advance is stored at the transmission destination, the data can be reproduced at any time as soon as the pair of data arrives.

Further, according to one aspect of the present invention, a reproducing apparatus capable of reproducing a data group having a reproduction order and having a non-constant data band of a unit data group to be transmitted in a time series order in a unit time according to the reproduction order. Is a distribution device capable of distributing the data band, and a comparison unit that compares the data band with a transmission band that can be used in a transmission path through which the data group is transmitted; and by the comparison, transmission loss is predicted in the unit data group. Data or data corresponding to the data belonging to the unit data group, and a data structure that does not reach the transmission band in which the extracted data is transmitted prior to the extracted unit data group And a transmission means for transmitting the data group established as described above on the transmission path.

According to this structure, even in the transmission data exceeding the transmission band, all the data is transmitted without discarding the data exceeding this band or compressing the data so as not to exceed the band. Can be placed on the road.

According to another aspect of the present invention, the data receiving device receives data transmitted from the data distributing device, and is applied to a data group transmitted from the transmitting means of the data distributing device. Detecting means for detecting the stored data, storage means for storing the detected data, and reconstructing means for reconstructing the stored data and a unit data group which is transmitted later and forms a pair with the data. And a reproducing means for reproducing the reconstructed unit data group at an arbitrary time point.

According to this structure, it is possible to store data that exceeds the band transmitted in advance and can be reproduced at any time as soon as paired data arrives. According to an aspect of the present invention, a computer is made to perform transmission between a transmitter and a receiver of a data group having a reproduction order and having a non-constant data band of a unit data group to be transmitted in a time series order in a unit time. And a function for comparing the data band with a transmission band that can be used in a transmission path for transmitting the data group, and data for which transmission loss is predicted in the unit data group or the unit data by the comparison. A function for extracting data corresponding to the data belonging to the group, and a transmission band for the data structure group that does not reach the transmission band transmitted prior to the extracted unit data group A function that does not exceed the above, a function that transmits the data group established as described above on the transmission path, and the data that is allocated to the transmitted data group A function of detecting, a function of accumulating the detected data, a function of reconstructing the accumulated data and a unit data group which is later transmitted and paired with the data, and a function of reconstructing the unit data group. The program is configured to have a function of playing back at any time.

By causing a computer to execute such a program, even for transmission data exceeding the transmission band,
All the data can be placed on the transmission line without discarding the data exceeding this band or compressing the data so as not to exceed the band. In addition, since the data that exceeds the band transmitted in advance is stored at the transmission destination, the data can be reproduced at any time as soon as the pair of data arrives.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows the amount of information of moving image data that changes over time. In this figure, the horizontal axis represents time, and the number following the symbol F is the number of time transitions in unit time intervals. Further, the vertical axis represents the amount of information of moving image data, and the boxes represented by alphabets and numbers are data units such as packets numbered in the order of reproduction. In this example, the reproduction is started from the data unit (a1) located at the lower position and further to the left. In order to simplify the following description, a set of data units (a1 to x5) is a data group, and a set of data units per unit time (for example,
a1 to a6) is a unit data group.

As is clear from this figure, the amount of information varies depending on the time. Among these, F4, F1
2, F13 and F23 have the maximum amount of information (hereinafter, maximum bandwidth), and in order to transmit this moving image data via a network such as the Internet, it is necessary to secure the maximum bandwidth in the transmission path. It is very difficult to secure the maximum bandwidth that video data has,
Data that exceeds the bandwidth that can be secured in the transmission path is lost.

FIG. 2 compares the information amount of the moving image data shown in FIG. 1 with the bandwidth that can be secured in the transmission path. The dotted line indicated by the symbol th in the figure is the threshold value th of the amount of information that can be transmitted in the transmission path per unit time. In this case, in addition to the above-mentioned maximum band, there is data in F6, F20, and F22 that is out of the band of the transmission path and is predicted to be lost. In the figure, data that exceeds the threshold th and is predicted to be lost during transmission is shown in black.

FIG. 3 shows an example in which the data predicted to be missing shown in FIG. 2 is accommodated in an empty band of another unit data group which does not exceed the threshold th. In this figure, the missing data is accommodated in the empty band of the unit data group transmitted prior to the unit data group to which it belongs, as indicated by the arrow in the figure. For example, the missing data d7 and d8 of F4 are F3
You can see how it is housed on C4. By transmitting each unit data group in this state, data loss during transmission can be prevented.

FIG. 4 shows a state in which, after transmitting the moving image data, the missing data stored in FIG. 3 is returned to the original arrangement shown in FIG. 2 at the transmission destination. Is indicated by the arrow. By returning to the original arrangement in this way, reproduction with the same quality as the original moving image data can be performed.

In this embodiment, the predicted missing data is counted from the end when the data units are arranged in time series in the unit data group and accommodated in the empty band. It is also possible to arbitrarily specify data units from the same unit data group as many as the number of data units predicted to be lost and to accommodate them in the free band without specifying them.

Here, the blocks necessary for performing the above transmission will be shown. FIG. 5 is a block diagram of a system that performs transmission by the above method. Reference numeral 1 denotes a comparison unit that checks the moving image data as shown in FIG. 1 and compares the moving image data as shown in FIG. 2 to see if it exceeds the threshold th of the amount of information permitted on the transmission path. Reference numeral 2 denotes an extraction unit that extracts the missing data predicted to be missing as a result of the comparison and the empty band of the unit data group transmitted prior to the unit data group to which the missing data belongs. A reference numeral 3 denotes a allocating unit for allocating the missing data to the vacant band of the unit data group which is transmitted in advance, in order from the earliest reproduction order, based on the extraction result. Four
Is a transmission unit for transmitting the data group, which has been allocated and has the information amount suppressed within the threshold th, to a transmission line. Reference numeral 5 denotes a receiver of a transmission destination that receives the transmitted data group. Reference numeral 6 denotes a detection unit that detects the missing data that was transmitted in advance from each received unit data group. A storage unit 7 stores the detected missing data. A reconstructing unit 8 reconstructs the received unit data group and the pair of missing data accumulated in the accumulating unit. A reproducing unit 9 reproduces the reconstructed moving image data in chronological order.

As shown in FIG. 6, the hardware configuration of such a system is used for both transmission and reception, as shown in FIG. 6, a calculation unit 11 for executing a program, a recording unit 12 for recording moving image data, a memory such as a ROM or a RAM. The communication unit 14 that communicates via the unit 13 and the transmission path can be configured via the bus 15.

Next, the operation of this system will be described according to the operation flow of FIG. First, the comparison unit 1 checks the moving image data to be transmitted (S1), and confirms the bandwidth available in the transmission path (S2). Then, the extraction unit 2 checks whether or not the unit data group fits in this band, and predicts missing data (S3). If there is missing data, the extraction unit 2 predicts the empty band of the unit data group transmitted prior to the unit data group to which it belongs (S4), and the allocation unit 3 stores the missing data in this empty band. (S5).
When the accommodation of the missing data is completed (S6), the transmission unit 4 transmits the data group to the transmission path (S7). Note that step S
If there is no missing data in 3, the data is transmitted as it is (S7).

When the receiving unit 5 receives the transmitted data group (S11), the detecting unit 6 checks the data group (S1).
2) The presence or absence of missing data is detected (S13). If there is missing data, the missing data is extracted and accumulated in the accumulation unit 7 (S14), and the other data is sent out (S15), and is combined and reproduced by the reproducing unit (S1).
6). If the missing data is not detected in step S13, it is confirmed whether or not the missing data to be paired is stored in the storage unit 7 (S17). If not, the data of the process of step S15 is stored. The data is transmitted and the data is reproduced (S16). When it is confirmed in step S17 that the unit data group and the missing data stored in the storage unit 7 paired with the unit data group are reconfigured in the reconstructing unit 8 and restored to the original state. (S
18). Then, in the process of step S15, the data is transmitted and the data is reproduced (S16).

In this operation, since the missing data is sent in advance, only the amount of data to be written in the storage unit 7 is sufficient, and the processing load on the transmission destination is also reduced.

Further, in consideration of the delay of the transmission data that may occur for reasons other than the above, it is also possible to store a certain amount of data group in the storage unit 7 before starting the reproduction.

Further, although the present embodiment has been described by using the moving image data, the present invention can also be applied to, for example, voice data and image data. Further, by using the data transmission method according to the present embodiment, bidirectional real-time communication such as a videophone can be performed with high quality without time difference.

Further, considering the above-mentioned transmission path as a band given in the atmosphere, high quality and more stable communication can be performed in wireless data communication such as packet communication in a mobile phone.

As described above, according to the present embodiment, the bandwidth of the transmission data can be averaged and the bandwidth can be secured, for example, 500 kbp.
Since the data can be transmitted in a low band, the data loss and the data loss due to the change of the band of the transmission line or the band over of the transmission data are eliminated, and the high quality and smooth reproduction can be performed. Further, since the missing data that causes the band over is sent and accumulated in advance, the data group arriving at the transmission destination is recombined with the missing data in sequence and played back, significantly reducing the waiting time until playback. It is possible to perform high-realtime reproduction between the transmission source and the transmission destination.

[0029]

As described above, according to the present invention, data can be transmitted in a band in which the band of transmission data can be secured, and therefore data loss or data loss due to band change of the transmission path or transmission data band over. Is eliminated, and high-quality and smooth data reproduction becomes possible. Furthermore, missing data that causes over-band transmission is sent and accumulated in advance, and the data group that arrives at the transmission destination is recombined with the missing data in sequence and reproduced, so the waiting time until reproduction is greatly shortened, and the transmission source It becomes possible to perform reproduction in high real time between the destination and the destination.

[Brief description of drawings]

FIG. 1 is an example showing an information amount of moving image data which changes with time.

FIG. 2 is an example in which the information amount of the moving image data shown in FIG. 1 is compared with the bandwidth available in the transmission path.

FIG. 3 is a threshold t for the data predicted to be missing shown in FIG.
This is an example of a case where the data is accommodated in an empty band of another unit data group that does not exceed h.

FIG. 4 is a diagram showing a state in which the missing data stored in FIG. 3 is returned to the original layout shown in FIG. 2 at the transmission destination of the moving image data.

FIG. 5 is a block diagram of the system.

FIG. 6 is a hardware configuration diagram of a system.

FIG. 7 is an operation flow of the system.

[Explanation of symbols]

1 comparison section 2 extractor 3 allocation department 4 transmitter 5 Receiver 6 detector 7 Storage 8 Reconstruction Department 9 Playback section

Claims (5)

[Claims] 1. A transmission method between a transmitter and a receiver of a data group having a reproduction order and in which a data band of a unit data group to be transmitted in a unit of time series order is not constant, the data band and the data The data is compared with a transmission band that can be used by a transmission line transmitted by the group, and by this comparison, data in which transmission loss is predicted in the unit data group or data corresponding to the data belonging to the unit data group is extracted, and the extraction is performed. The data group that is established as described above is applied to a data structure group that does not extend to the transmission band that is transmitted prior to the unit data group that has been extracted so as not to exceed the transmission band. Is transmitted over the transmission line, the data allocated to the transmitted data group is detected, the detected data is accumulated, and the accumulated data is transmitted later and paired with the data. Unit reconstructs the data group, which reproduction unit data group said reconstituted at any time, store-and streaming combination data transmission method characterized by comprising. 2. A transmission system for handling a data group having a reproduction order and in which a data band of a unit data group to be transmitted in a time series order is not constant, wherein the data band and the data group are transmitted. Comparing means for comparing with a transmission band available in the transmission path, and extracting means for extracting data for which transmission loss is predicted in the unit data group or data corresponding to the data belonging to the unit data group by the comparison; Allocation means for allocating the extracted data to a data structure group that does not extend to the transmission band, which is transmitted prior to the unit data group from which the extraction is performed, so as not to exceed the transmission band, and as described above. Transmission means for transmitting the established data group on the transmission path, detection means for detecting the data allocated to the transmitted data group, and storing the detected data Accumulating means for accumulating, reconstructing means for reconstructing the accumulated data and a unit data group which is later transmitted and paired with the data, and reproducing for reproducing the reconstructed unit data group at an arbitrary time point A storage-type and streaming-combined data transmission system comprising: 3. A distribution device capable of distributing a data group having a reproduction order and having a non-constant data band of a unit data group to be transmitted in a time series order to a reproduction device according to the reproduction order. Comparing means for comparing the data band with a transmission band available on a transmission path for transmitting the data group, and data for which transmission loss is predicted in the unit data group by the comparison or belonging to the unit data group Extraction means for extracting data corresponding to the data, and a data structure group that does not extend to the transmission band that is transmitted prior to the unit data group in which the extracted data is extracted, and does not exceed the transmission band. A data distribution apparatus, comprising: a allocating unit that allocates as described above; and a transmitting unit that transfers the data group established as described above on the transmission path. 4. A data receiving device for receiving the data transmitted from the data distribution device according to claim 3, wherein the data receiving device is applied to the data group transmitted from the transmission means of the data distribution device. Detecting means for detecting data, accumulating means for accumulating the detected data, reconfiguring means for reconfiguring the accumulated data and a unit data group which is later transmitted and paired with the data, and the reconfiguring means And a reproducing means for reproducing the generated unit data group at an arbitrary time point. 5. A program for causing a computer to perform transmission between a transmitter and a receiver of a data group having a reproduction order and having a non-constant data band of a unit data group to be transmitted in a time series order in a unit time, A function of comparing the data band with a transmission band that can be used in a transmission path for transmitting the data group, data for which transmission loss is predicted in the unit data group by the comparison, or data corresponding to the unit data group. And a function to extract the data of the above, and to apply the extracted data to a data structure group that does not reach the transmission band preceding the unit data group from which the extraction is performed so as not to exceed the transmission band. A function, a function of transmitting the data group established as described above on the transmission path, and a function of detecting the data allocated to the transmitted data group , A function of accumulating the detected data, a function of reconstructing the accumulated data and a unit data group which is later transmitted and paired with the data, and a function of reconstructing the unit data group at any time. A computer-executable storage-type and streaming-combined data transmission program characterized by having a playback function.