JP2006295601A - Communication system, transmitting apparatus and method, receiving apparatus and method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To protect contents. <P>SOLUTION: A hierarchy determination part 152 compares the bit rate of a maximum writing speed of a storage which is supplied from a communication part 151 with a bit rate in each hierarchy of hierarchically encrypted contents which are stored in a hierarchy information holding part 153 to determine the hierarchy of the hierarchically encrypted contents. A packetizer 154 acquires the contents of hierarchy corresponding to the determined hierarchy from contents acquired from a contents recording part 155 and stores the acquired hierarchical contents in a packet. The communication part 151 transmits the packet supplied from the packetizer 154 by streaming distribution to protect the contents. This invention can be applied to a communication system. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a communication system, a transmission apparatus and method, a reception apparatus and method, and a program, and more particularly to a communication system, transmission apparatus and method, reception apparatus and method, and program that can protect content.

  In recent years, services that transmit and provide image data or audio data via various communication media such as the Internet are generally performed. In particular, in recent years, in addition to download-type transmission scheme services, more stream-type transmission scheme services have been provided.

  In a download-type transmission method service, a receiving device receives a file storing image data or audio data transmitted from a transmitting device, and records the received file in its own storage medium (storage). After the recording of the file is completed, the receiving device reproduces an image or sound based on the recorded file. In the download type transmission method service, the file cannot be reproduced until the file recording is completed. Therefore, the download type transmission method service is not suitable for long-time reproduction or real-time reproduction.

  On the other hand, in a stream-type transmission system service, a receiving apparatus receives data transmitted from a transmitting apparatus and reproduces an image or sound based on the received data in parallel with the data. The stream-type transmission method is used for Internet services such as Internet telephone, remote video conference, and video on demand.

  In a streaming transmission method, data transmitted from a transmission device is generally referred to as streaming data.

  As a more specific example, a streaming transmission method uses an Internet Protocol (IP) packet that stores an MPEG stream generated by applying MPEG (Moving Picture Experts Group) encoding processing to image data, and the Internet. Used in systems that transmit through. In this system, a PC (Personal Computer), PDA (Personal Digital Assistance), or mobile phone, which is a receiving device, receives an IP packet and reproduces an image.

  The stream-type transmission method is suitable for real-time communication such as video-on-demand or live video streaming, video conferencing, or videophone. In addition, unlike the town road type, the streaming transmission method does not record content such as a moving image as a file in the storage, so it is generally considered useful from the viewpoint of content protection.

  In real-time communications such as video-on-demand, for example, from a device with a low-resolution display and a low processing capacity CPU (Central Processing Unit) such as a mobile phone, a high-resolution display and processing capability such as a desktop personal computer. As a technique for executing reception processing and display processing according to processing capability in various reception devices up to a device having a high CPU, a method of executing transmission and reception data in a hierarchical manner, that is, a hierarchy A communication system using encoded data that has been encoded has been considered.

  Examples of such a compression method that enables hierarchical encoding include a video stream based on MPEG4 (Moving Picture Experts Group phase 4) and JPEG2000. In MPEG4, the Fine Granuality Scalability technology will be incorporated into the standard to be profitable, and this hierarchical coding technology will deliver from a low bit rate (the amount of data flowing per second) to a high bit rate in a scalable manner. Is possible. Further, JPEG2000 based on wavelet transform can be packetized based on spatial resolution or hierarchically based on image quality by taking advantage of the characteristics of wavelet transform. JPEG2000 can store hierarchical data in a file format according to the Motion JPEG2000 (Part 3) standard that can handle not only still images but also moving images.

  Conventionally, data to be transmitted by a transmission apparatus has to be prepared in different formats according to the capability of the reception apparatus and different data according to the transmission rate. However, this hierarchical encoding differs from one file data. Data can be distributed simultaneously to the receiving device with the capability.

  Furthermore, there is a communication system that suppresses buffer overflow and buffer underflow by setting a decoding time reflecting a clock difference between system clocks in each of a distribution server and a client PC (for example, Patent Document 1).

JP 2005-27209 A

  However, although streaming data is originally discarded along with reproduction by the receiving device, the content may be reconstructed later by recording the packet received as streaming data in the storage in the receiving device. There was a problem that there was.

  Further, for example, the communication system disclosed in Japanese Patent Application Laid-Open No. 2005-27209 can suppress buffer overflow and buffer underflow in the receiving apparatus, but records packets received as streaming data in the storage. Later, there was a possibility of being reconfigured as content.

  The present invention has been made in view of such a situation, and makes it possible to protect content.

  In the communication system of the present invention, the receiving device calculates a first speed indicating the fastest writing speed among the writing speeds to the respective recording media, and the calculated first speed is addressed to the transmitting apparatus. A first transmission means for transmitting, wherein the transmission apparatus receives the first speed transmitted from the reception apparatus, the received first speed, and the hierarchy in the hierarchically encoded data. By comparing the second speed indicating the transfer speed for each of the data layers from the lowest layer indispensable for decoding to the higher layer for higher quality decoding, Determining means for determining the highest hierarchy of data to be transmitted; acquisition means for acquiring hierarchy data from hierarchically encoded data based on the determined hierarchy; and second means for transmitting the acquired hierarchy data Sending Characterized in that it comprises a means.

  The receiving apparatus of the present invention includes a calculating unit that calculates a first speed indicating the fastest writing speed among writing speeds to each recording medium, and a transmitting unit that transmits the calculated first speed to the transmitting apparatus. It is characterized by providing.

  The receiving device of the present invention includes generating means for generating a message of the session control message protocol by storing the calculated first speed in a message of the session control message protocol, and the transmitting means transmits the generated message to the transmitting device. It is transmitted to address.

  The receiving method of the present invention controls a calculation step of calculating a first speed indicating the fastest writing speed among writing speeds to each recording medium, and controls transmission of the calculated first speed to the transmission device. And a transmission control step.

  The program of the present invention controls a calculation step for calculating a first speed indicating the fastest writing speed among the writing speeds to the respective recording media, and transmission of the calculated first speed to the transmission apparatus. A transmission control step.

  The transmitting apparatus of the present invention includes a receiving means for receiving a first speed indicating the fastest writing speed among the writing speeds to each recording medium transmitted from the receiving apparatus, and the received first speed. Is compared with the second rate indicating the transfer rate for each layer in the layer-encoded data, so that higher-order decoding for higher quality decoding can be performed from the lowest layer indispensable for decoding. Determining means for determining the highest hierarchy of the data to be transmitted among the data hierarchy up to the hierarchy, and acquiring means for acquiring the data of the hierarchy from the hierarchically encoded data based on the determined hierarchy; And a second transmission means for transmitting the acquired data of the hierarchy.

  When the second speed is higher than the first speed, the determining means determines the data hierarchy from the lowest hierarchy indispensable for decoding to the higher hierarchy for higher quality decoding. Of these, the highest hierarchy of data to be transmitted can be determined.

  The transmission apparatus of the present invention includes storage means for storing the second speed for each layer of hierarchically encoded data, and the determining means includes the received first speed and the stored second speed. And the hierarchy is determined by comparing with.

  The transmission method of the present invention includes: a reception control step for controlling reception of a first speed indicating the fastest writing speed among the writing speeds to each recording medium transmitted from the receiving apparatus; In order to perform higher quality decoding from the lowest layer indispensable for decoding by comparing the rate of 1 and the second rate indicating the transfer rate for each layer in the hierarchically encoded data A determination step for determining the highest hierarchy of data to be transmitted among the hierarchy of data up to a higher hierarchy, and acquisition of hierarchy data from hierarchically encoded data based on the determined hierarchy And a transmission control step for controlling transmission of the acquired hierarchical data.

  The program of the present invention includes a reception control step for controlling reception of a first speed indicating the fastest writing speed among the writing speeds to each recording medium transmitted from the receiving device, and the received first Is compared with the second speed indicating the transfer speed for each layer in the hierarchically encoded data, so that higher quality decoding can be performed from the lowest layer indispensable for decoding. A determination step for determining the highest layer of data to be transmitted among layers of data up to a higher layer, and an acquisition step for acquiring layer data from the hierarchically encoded data based on the determined layer And a transmission control step for controlling the transmission of the acquired data of the hierarchy.

  In the communication system of the present invention, the first speed indicating the fastest writing speed among the writing speeds to the respective recording media is calculated by the receiving apparatus, and the calculated first speed is transmitted to the transmitting apparatus. The first rate transmitted from the receiving device is received by the transmitting device, the received first rate, and the second rate indicating the transfer rate for each layer in the hierarchically encoded data, Of the data from the lowest layer indispensable for decoding to the higher layer for higher quality decoding, the highest layer of the data to be transmitted is determined. Based on the determined hierarchy, the hierarchy data is acquired from the hierarchically encoded data, and the acquired hierarchy data is transmitted.

  In the receiving apparatus and method and the program of the present invention, the first speed indicating the fastest writing speed among the writing speeds to the respective recording media is calculated, and the calculated first speed is addressed to the transmitting apparatus. Sent.

  In the transmitting apparatus and method and the program of the present invention, the first speed indicating the fastest writing speed among the writing speeds to the respective recording media transmitted from the receiving apparatus is received and received. By comparing the first rate and the second rate indicating the transfer rate for each layer in the hierarchically encoded data, higher quality decoding is performed from the lowest layer indispensable for decoding. Therefore, the highest hierarchy of data to be transmitted is determined from the hierarchy of data up to the higher hierarchy for the hierarchy, and the hierarchy data is acquired from the hierarchically encoded data based on the determined hierarchy. The data of the selected hierarchy is transmitted.

  According to the present invention, content can be protected. Moreover, according to the present invention, it is possible to protect the content more reliably.

  BEST MODE FOR CARRYING OUT THE INVENTION The best mode of the present invention will be described below. The correspondence relationship between the disclosed invention and the embodiments is exemplified as follows. Although there are embodiments which are described in this specification but are not described here as corresponding to the invention, the embodiments correspond to the invention. It does not mean that it is not a thing. Conversely, even if an embodiment is described herein as corresponding to an invention, that means that the embodiment does not correspond to an invention other than the invention. It is not a thing.

  Further, this description does not mean all the inventions described in the specification. In other words, this description is for the invention described in the specification and not claimed in this application, i.e., for the invention that will be applied for in the future or that will appear as a result of amendment and added. It does not deny existence.

  According to the present invention, a communication system is provided. In this communication system (for example, the streaming distribution system 1 in FIG. 1), the receiving device (for example, the client 11 in FIG. 1) has a first speed indicating the fastest writing speed among the writing speeds to the respective recording media. Calculating means (for example, the rate specifying unit 101 in FIG. 3), and first transmitting means (for example, the transmitting unit 121 in FIG. 3) for transmitting the calculated first speed to the transmission device, The transmitting device (for example, the server 13 in FIG. 1) receives the first speed transmitted from the receiving device (for example, the receiving unit 161 in FIG. 4), the received first speed, By comparing the second rate indicating the transfer rate for each layer in the hierarchically encoded data, the higher layer for higher quality decoding from the lowest layer indispensable for decoding Ma Among the data hierarchies, the determining means for determining the highest hierarchy of the data to be transmitted (for example, the hierarchy determining unit 152 in FIG. 4), and from the hierarchically encoded data based on the determined hierarchy, An acquisition unit (for example, the packetizer 154 in FIG. 4) for acquiring data and a second transmission unit (for example, the transmission unit 162 in FIG. 4) for transmitting the acquired hierarchical data are provided.

  According to the present invention, a receiving device is provided. The receiving device (for example, the client 11 in FIG. 1) is a calculating unit (for example, the rate specifying unit 101 in FIG. 3) that calculates a first speed indicating the fastest writing speed among the writing speeds to the respective recording media. ) And a transmission means (for example, the transmission unit 121 in FIG. 3) for transmitting the calculated first speed to the transmission device.

  The transmission device includes a generation unit (for example, the packet generation unit 103 in FIG. 3) that generates a message of the session control message protocol by storing the calculated first speed in a message of the session control message protocol, and the transmission unit Can transmit the generated message to the transmission device.

  According to the present invention, a receiving method is provided. This reception method includes a calculation step (for example, the process of step S12 in FIG. 5) for calculating the first speed indicating the fastest writing speed among the writing speeds to the respective recording media, and the calculated first speed. Including a transmission control step (for example, the process of step S14 in FIG. 5) for controlling transmission to the transmission device.

  According to the present invention, a program is provided. This program calculates a first speed indicating the fastest writing speed among the writing speeds to the respective recording media (for example, the process of step S12 in FIG. 5), and the calculated first speed. A transmission control step (for example, the process of step S14 in FIG. 5) for controlling transmission to the transmission device is executed.

  This program can be stored in a storage medium (for example, the magnetic disk 51 in FIG. 2).

  According to the present invention, a transmission device is provided. The transmitting device (for example, the server 13 in FIG. 1) receives a first means (first server speed) indicating the fastest writing speed among the writing speeds of the respective recording media transmitted from the receiving apparatus. For example, it is indispensable for decoding by comparing the receiving unit 161) of FIG. 4 with the received first rate and the second rate indicating the transfer rate for each layer in the hierarchically encoded data. Determining means for determining the highest hierarchy of data to be transmitted among the hierarchy of data from the lowest hierarchy to a higher hierarchy for decoding with higher quality (for example, the hierarchy decision unit 152 in FIG. 4) ) And an acquisition unit (for example, the packetizer 154 in FIG. 4) that acquires hierarchical data from hierarchically encoded data based on the determined hierarchy, and a transmission unit that transmits the acquired hierarchical data ( Eg to a transmission means) and Fig.

  When the second speed is higher than the first speed, the determining means determines the data hierarchy from the lowest hierarchy indispensable for decoding to the higher hierarchy for higher quality decoding. Of these, the highest hierarchy of data to be transmitted can be determined.

  The transmission device includes a storage unit (for example, the hierarchical information holding unit 153 in FIG. 4) that stores the second rate for each layer of hierarchically encoded data, and the determining unit determines the received first rate and The hierarchy can be determined by comparing the stored second speed.

  According to the present invention, a transmission method is provided. This transmission method is a reception control step for controlling reception of a first speed indicating the fastest writing speed among the writing speeds to the respective recording media transmitted from the receiving device (for example, step in FIG. 9). By comparing the received first speed with the second speed indicating the transfer speed for each layer in the hierarchically encoded data, the lowest layer indispensable for decoding is obtained. A decision step (for example, the process of step S114 in FIG. 9) for deciding the highest hierarchy of data to be transmitted among the hierarchy of data up to a higher hierarchy for decoding with higher quality Based on the hierarchy, the acquisition step (for example, the process of step S131 in FIG. 11) for acquiring the hierarchy data from the hierarchically encoded data, and the acquired hierarchy data Transmission control step of controlling the signal (for example, step S135 in FIG. 11) and a.

  According to the present invention, a program is provided. This program is a reception control step (for example, step S111 in FIG. 9) for controlling reception of a first speed indicating the fastest writing speed among the writing speeds to each recording medium transmitted from the receiving device. ) And the received first speed and the second speed indicating the transfer speed for each layer in the hierarchically encoded data, from the lowest layer indispensable for decoding, A determination step (for example, the process of step S114 in FIG. 9) for determining the highest layer of data to be transmitted among the layers of data up to a higher layer for decoding with higher quality, and the determined layer The acquisition step (for example, the process of step S131 in FIG. 11) for acquiring the hierarchy data from the hierarchically encoded data, and the acquired hierarchy data Transmission control step of controlling transmission (for example, step S135 in FIG. 11) and to the execution.

  This program can be stored in a storage medium (for example, the magnetic disk 51 in FIG. 2).

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration of an embodiment of a streaming distribution system 1 to which the present invention is applied. The streaming distribution system 1 is an example of a communication system according to the present invention. In this streaming distribution system 1, a client 11 and a server 13 are connected to a packet communication network 12 such as the Internet.

  The client 11 is composed of, for example, a PC, a PDA, or a mobile phone, and receives a packet transmitted from the server 13 via the packet communication network 12. The client 11 is an example of a receiving device of the present invention.

  The client 11 extracts image data from the received packet and supplies the extracted image data to an output device (not shown). The output device is constituted by a display such as an LCD (Liquid Crystal Display) or a CRT (Cathode Ray Tube), and may be built in the client 11 or provided as a device separate from the client 11. Also good.

  Image data is an example of streaming data. The streaming data may be data that is requested to be transmitted or received sequentially as time passes, such as audio data or real-time control data.

  The server 13 is configured by, for example, a dedicated server or a PC, and when a streaming data distribution request is made from the client 11, the server 13 stores the image data recorded by itself in the packet, and the packet is transmitted to the packet. The data is transmitted to the client 11 via the network 12. The server 13 is an example of a transmission device according to the present invention.

  The packet communication network 12 is a transmission path including a wired or wireless communication line, a network, or the Internet, and transmits a packet transmitted from the server 13 to the client 11 with a predetermined delay time.

  In the example of the streaming distribution system 1 shown in FIG. 1, one client 11 and one server 13 are provided, but actually, the server 13 sends streaming data to a plurality of clients 11. Therefore, a plurality of clients 11 are connected via the packet communication network 12. Similarly, a plurality of servers 13 may be provided.

  FIG. 2 is a block diagram illustrating an example of the configuration of the client 11.

  The CPU 31 of the server 12 executes various processes according to a program recorded in a ROM (Read Only Memory) 32 or a recording unit 38. A RAM (Random Access Memory) 33 appropriately stores programs executed by the CPU 31 and data. The CPU 31, ROM 32, and RAM 33 are connected to each other by a bus 34.

  An input / output interface 35 is also connected to the CPU 31 via the bus 34. The input / output interface 35 is connected to an input unit 36 including a keyboard, a mouse, and a microphone, and an output unit 37 including a display and a speaker. The CPU 31 executes various processes in response to commands input from the input unit 36. Then, the CPU 31 outputs an image, sound, or the like obtained as a result of the processing to the output unit 37.

  The recording unit 38 connected to the input / output interface 35 is composed of, for example, a hard disk and records programs executed by the CPU 31 and various data. The communication unit 39 communicates with an external device via the communication network 13, the Internet, another network, or a communication medium.

  A program may be acquired via the communication unit 39 and recorded in the recording unit 38.

  The drive 40 connected to the input / output interface 35, when a magnetic disk 51, an optical disk 52, a magneto-optical disk 53, or a semiconductor memory 54 is mounted, drives them, and programs and data recorded there. Get etc. The acquired program and data are transferred to the recording unit 38 and recorded as necessary.

  Since the server 13 is configured in the same manner as the client 11, the description and description thereof are omitted. In addition, the client 11 and the server 13 are not limited to the internal structure shown in FIG. 2, and functions can be added or deleted as necessary, and have a configuration corresponding to the functions. Is possible.

  FIG. 3 is a block diagram illustrating a functional configuration of the client 11.

  The client 11 is configured to include a communication unit 39, a rate specification unit 101, a storage 102-1, a storage 102-2, a packet generation unit 103, a buffer 104, and a decoder 105.

  The rate specifying unit 101 performs a maximum writing speed determination process for determining the maximum writing speed, which is the fastest writing speed among the storage writing speeds of the client 11.

  For example, the rate specifying unit 101 measures the writing speeds of the storage 102-1 and the storage 102-2 of the client 11, and determines the fastest (larger) writing speed among the measured writing speeds as the maximum writing speed. The rate designation unit 101 supplies the determined maximum writing speed bit rate to the packet generation unit 103.

  The rate specifying unit 101 is configured to include a writing speed acquisition unit 111 and a maximum writing speed calculation unit 112.

  The writing speed acquisition unit 111 acquires the storage writing speed of the client 11. The writing speed acquisition unit 111 supplies the acquired writing speed of the storage to the maximum writing speed calculation unit 112. For example, the writing speed acquisition unit 111 acquires the writing speed from each of the storage 102-1 and the storage 102-2 other than the main memory (for example, the RAM 33), and sends the acquired writing speed to the maximum writing speed calculation unit 112. Supply.

  The maximum writing speed calculation unit 112 calculates the maximum writing speed based on the storage writing speed supplied from the writing speed acquisition unit 111. The maximum write speed calculation unit 112 supplies the calculated maximum write speed bit rate to the packet generation unit 103.

  The storage 102-1 includes, for example, an external storage device such as a hard disk, magnetic tape, CD-R (Compact Disc Recordable), DVD-R (Digital Versatile Disc Recordable), or MD (Mini-Disc) (trademark). The The storage 102-1 records programs executed by the CPU 31 and various data.

  Similar to the storage 102-1, the storage 102-2 is composed of a hard disk, for example, and records programs executed by the CPU 31 and various data.

  The packet generation unit 103 generates an RTSP packet by storing the bit rate of the maximum writing speed supplied from the maximum writing speed calculation unit 112 in an RTSP (Real Time Streaming Protocol) packet. The packet generation unit 103 supplies the generated RTSP packet to the communication unit 39.

  Here, although details will be described later, RTSP is a protocol for distributing audio, moving images, and the like in real time on a TCP / IP (Transmission Control Protocol / Internet Protocol) network such as the Internet. In general, RTSP is used as a protocol in a streaming transmission system. In the present invention, a packet transmitted and received between the client 11 and the server 13 in accordance with the RTSP protocol will be referred to as an RTSP packet.

  For example, the packet generation unit 103 includes the bit rate of the maximum writing speed supplied from the maximum writing speed calculation unit 112 and information indicating the content selected by the user supplied from the input unit 36 (hereinafter referred to as a content name). ) To generate an RTSP packet and supply the generated RTSP packet to the communication unit 39.

  The communication unit 39 corresponds to the communication unit 39 in FIG. 2 and communicates with an external device via the packet communication network 12, the Internet, other networks, or a communication medium.

  The communication unit 39 is configured to include a transmission unit 121 that transmits various packets and a reception unit 122 that receives various packets.

  The transmission unit 121 transmits the RTSP packet supplied from the packet generation unit 103 to the server 13 via the packet communication network 12. The receiving unit 122 supplies the packet transmitted from the server 13 to the buffer 104 via the packet communication network 12.

  The buffer 104 temporarily stores the image data extracted from the packet supplied from the communication unit 39.

  The decoder 105 decodes the image data stored in the buffer 104 by a decoding method corresponding to the encoder (not shown) of the server 13 and displays the decoded image data on, for example, an LCD or CRT display. As a result, the image is displayed on the screen of the output unit 37, and streaming is started.

  Hereinafter, when it is not necessary to distinguish between the storage 102-1 and the storage 102-2, they are simply referred to as the storage 102.

  FIG. 4 is a block diagram illustrating a functional configuration of the server 13.

  The server 13 is configured to include a communication unit 151, a hierarchy determination unit 152, a hierarchy information holding unit 153, a packetizer 154, and a content recording unit 155.

  The communication unit 151 corresponds to the communication unit 39 in FIG. 2 and communicates with an external device via the packet communication network 12, the Internet, other networks, or a communication medium.

  The communication unit 151 is configured to include a reception unit 161 that receives various packets and a transmission unit 162 that transmits various packets.

  The receiving unit 161 supplies the packet transmitted from the client 11 to the hierarchy determining unit 152 via the packet communication network 12. The transmission unit 162 causes the packet supplied from the packetizer 154 to be transmitted to the client 11 via the packet communication network 12.

  The hierarchy determining unit 152 performs hierarchy determination processing. For example, the hierarchy determining unit 152 determines the hierarchy N based on the bit rate stored in the RTSP packet transmitted from the client 11 and based on the bit rate supplied from the communication unit 151. N is supplied to the packetizer 154. Details of the hierarchy determination process will be described later.

  Here, the hierarchy N is a parameter for storing a value for determining a hierarchy in the hierarchical encoding, and stores a numerical value corresponding to each hierarchy of the hierarchical encoding.

  The hierarchy information holding unit 153 holds (stores) the hierarchy information, and supplies the stored hierarchy information to the hierarchy determining unit 152 in response to a request from the hierarchy determining unit 152. Further, the hierarchical information holding unit 153 is based on the content recorded in the content recording unit 155 and compressed with the hierarchical code (hierarchically encoded content before the hierarchy is determined) for each layer in the content. The bit rate is stored as hierarchical information.

  Here, layer information is information indicating the bit rate of each layer in layer coding. For example, in the case of four-layer hierarchical coding, the hierarchical information includes the bit rate of encoded data of the first layer, the bit rate of encoded data from the first layer to the second layer, and from the first layer. The information includes the bit rate of the encoded data up to the third layer and the bit rate of the encoded data from the first layer to the fourth layer.

  The packetizer 154 performs streaming processing by supplying a packet storing image data to the communication unit 151. For example, the packetizer 154 acquires hierarchically encoded content (image data) from the content recording unit 155. Based on the hierarchy N supplied from the hierarchy determining unit 152, the packetizer 154 stores image data corresponding to the hierarchy N in acquired packets (image data) in a packet of a predetermined method, and stores the image data. By supplying the packet to the communication unit 151, the packet is transmitted to the client 11 via the packet communication network 12.

  The content recording unit 155 records hierarchically encoded content (image data). The content recording unit 155 supplies the recorded content to the packetizer 154, for example, every frame in response to a request from the packetizer 154.

  Next, referring to FIG. 5 to FIG. 12, as an example of processing of the streaming distribution system 1 of the present invention, the client 11 receives streaming data transmitted from the server 13 via the packet communication network 12. Processing will be described. First, details of processing performed by the client 11 will be described with reference to FIGS. 5 to 7, and then details of processing performed by the server 13 will be described with reference to FIGS.

  FIG. 5 is a flowchart for explaining data transmission / reception processing by the client 11.

  In step S11, the input unit 36 accepts content selection.

  For example, the input unit 36 selects the content (video) of “sports soccer” from the content displayed on the screen of the output unit 37 of the client 11 such as an LCD or a CRT display by the user's operation. If it is, the content name which is information indicating “sports soccer” is supplied to the packet generation unit 103.

  In the following description, as an example of the streaming distribution system 1, the client 11 receives streaming data of (sports soccer) content (video) transmitted from the server 13 via the packet communication network 12. It becomes processing.

  In step S <b> 12, the rate specifying unit 101 performs a maximum writing speed determination process.

  For example, the rate specifying unit 101 measures the writing speeds of the storage 102-1 and storage 102-2 provided in the client 11, determines the fastest writing speed among the measured writing speeds as the maximum writing speed, The determined maximum writing speed bit rate is supplied to the packet generator 103. Specifically, when the rate designating unit 101 determines a bit rate of 25 (Mbps) as the maximum writing speed, the rate designating unit 101 supplies the packet generating unit 103 with a bit rate of 25 (Mbps). Details of the processing for determining the maximum writing speed will be described later.

  In step S <b> 13, the packet generation unit 103 generates an RTSP packet based on the maximum write speed bit rate supplied from the rate specifying unit 101, and supplies the generated RTSP packet to the communication unit 39.

  For example, in step S <b> 13, the packet generation unit 103 supplies the maximum writing speed bit rate of 25 (Mbps) supplied from the maximum writing speed calculation unit 112 and the “sport soccer” supplied from the input unit 36. The RTSP packet is generated by storing the bit rate of the maximum writing speed of 25 (Mbps) and the content name indicating “Sports Soccer” in the RTSP packet based on the content name indicating, and communicating the generated RTSP packet To the unit 39.

  Here, as described above, the RTSP packet is transmitted and received between the client 11 and the server 13 in accordance with the RTSP protocol, but the normal RTSP packet has a bit rate of the maximum writing speed. Since the information to be shown is not stored, the bit rate of the maximum writing speed is stored in the RTSP packet by adding a parameter indicating the bit rate of the maximum writing speed to the normal RTSP packet.

  FIG. 6 is a diagram illustrating an example of an RTSP packet (hereinafter also referred to as an extended RTSP packet) that stores a bit rate of the maximum writing speed.

  “SETUP rtsp: //192.168.0.1/home/data/data.avi RTSP / 1.0” on the first line is distributed by the server 13 with the IP address “192.168.0.1”, “/ home / data / Indicates that streaming distribution of content with the file name “data.avi” is requested.

  For example, when the content “sports soccer” is selected from the content displayed on the screen of the output unit 37 of the client 11 by the user's operation, “rtsp” indicating the file name of the distribution destination of the content Store “: //192.168.0.1/home/data/data.avi” in the extended RTSP packet. That is, in this case, the content “sport soccer” is a file “data.avi” recorded in the directory “/ home / data /” of the server 13 with the IP address “192.168.0.1”. (Hereafter, this file name will be described as “/home/data/data.avi”).

  “CSeq: 1” on the second line is a sequence number indicating the order of transmission. That is, since the sequence number is “1”, it indicates that the extended RTSP packet is the first packet exchanged in the communication between the client 11 and the server 13.

  “Transport: RTP / UDP; unicast; client_port = 1234-1235; ssrc = 123456” on the third line indicates that the communication between the client 11 and the server 13 is a real-time distribution protocol RTP / UDP (Real- This indicates that communication is performed by unicast according to time transport protocol / user datagram protocol), and the port number of the client 11 at that time is “1234-1235”.

  “DISK: 25 Mbps” on the fourth line indicates that the bit rate of the maximum writing speed is “25 Mbps”. That is, by adding an extension parameter that is DISK to the SETUP method of the RTSP packet, the bit rate of the maximum writing speed of “25 Mbps” can be notified to the server 13.

  In the above-described example, the method of storing the bit rate of the maximum writing speed in the RTSP packet has been described as the method of notifying the server 13 of the bit rate of the maximum writing speed. However, the method is not limited to the method of storing in the RTSP packet. Any method that can notify the server 13 of the bit rate of the maximum writing speed, such as a method of storing in a message of a session control message protocol that is a protocol for controlling a session other than the RTSP packet, may be used. That is, the RTSP packet is an example of a session control message protocol.

  Returning to the flowchart of FIG. 5, in step S <b> 14, the communication unit 39 transmits the RTSP packet supplied from the packet generation unit 103 to the server 13 via the packet communication network 12.

  In step S <b> 15, the client 11 starts streaming by receiving streaming data determined by the bit rate of the maximum writing speed transmitted from the server 13 via the packet communication network 12.

  For example, the communication unit 39 is the streaming data of the content (video) of “sports football” transmitted from the server 13 via the packet communication network 12 and determined by the bit rate of the maximum writing speed. The streaming data stored in the packet is received. The communication unit 39 extracts the image data of the content “sport soccer” from the received packet, and supplies the extracted image data to the buffer 104. The buffer 104 temporarily stores the image data supplied from the communication unit 39. The decoder 105 decodes the image data stored in the buffer 104 by a decoding method corresponding to the encoder (not shown) of the server 13, and obtains the decoded image data from the LCD or CRT display. Streaming of the content “sports soccer” is started by outputting to the screen of the output unit 37 of the client 11.

  The streaming ends when, for example, the instruction from the input unit 36 or the streaming data transmitted from the server 13 ends, and thereby the data transmission / reception process in the client 11 ends.

  In this way, the fastest writing speed among the writing speeds of the storage of the client 11 is determined, and the bit rate of the determined writing speed is notified to the server 13, so that the streaming data distributed from the server 13 The bit rate becomes faster than the bit rate of the storage 102, and packets received as streaming data cannot be recorded in the storage 102 on the client 11 side. As a result, the streaming data cannot be captured in the client 11, so that the content can be protected.

  Next, details of the process for determining the maximum writing speed in step S12 in FIG. 5 will be described with reference to the flowchart in FIG.

  In step S31, the writing speed acquisition unit 111 acquires the writing speed of the storage 102. The writing speed acquisition unit 111 supplies the acquired writing speed of the storage 102 to the maximum writing speed calculation unit 112.

  For example, in step S31, the writing speed acquisition unit 111 sets the writing speeds of the storage 102-1 and the storage 102-2 of the client 11 other than the main memory (for example, the RAM 33) to 25 (Mbps) and 20 (Mbps). ), The writing speeds of 25 (Mbps) and 20 (Mbps) are acquired from the storage 102-1 and the storage 102-2, respectively, and the acquired 25 (Mbps) and 20 (Mbps). The writing speed is supplied to the maximum writing speed calculation unit 112.

  In addition, the writing speed acquisition unit 111 is a method of acquiring the writing speed. In practice, the writing speed acquisition unit 111 acquires data by writing data to the storage 102 and measuring the time required for the writing speed. Any method that can acquire the writing speed of the storage 102, such as a method of acquiring by reading a parameter indicating the writing speed of the storage 102, may be used.

  In step S <b> 32, the maximum writing speed calculation unit 112 calculates the maximum writing speed based on the storage writing speed supplied from the writing speed acquisition unit 111. The maximum writing speed calculation unit 112 supplies the calculated bit rate of the maximum writing speed to the packet generation unit 103, returns the process to step S12 in FIG. 5, and executes the processes after step S13.

  For example, in step S32, the maximum writing speed calculation unit 112 uses 25 (Mbps) and 20 (Mbps) based on the writing speeds of 25 (Mbps) and 20 (Mbps) supplied from the writing speed acquisition unit 111. Of the certain writing speeds, the fastest writing speed, which is 25 (Mbps), is calculated as the maximum writing speed, and the calculated maximum writing speed bit rate of 25 (Mbps) is supplied to the packet generation unit 103. To do.

  The details of the processing performed by the client 11 have been described above. Next, details of processing performed by the server 13 will be described with reference to FIGS. 8 to 12.

  First, the data transmission / reception processing by the server 13 will be described with reference to FIG.

  In step S91, the hierarchy determining unit 152 performs a hierarchy determining process. For example, the hierarchy determining unit 152 determines the hierarchy N based on the bit rate transmitted from the client 11 and supplied from the communication unit 151, and supplies the determined hierarchy N to the packetizer 154. To do. Details of the hierarchy determination process will be described later.

  In step 92, the packetizer 154 performs streaming processing. For example, the packetizer 154 acquires hierarchically encoded content (image data) from the content recording unit 155. Based on the hierarchy N supplied from the hierarchy determination unit 152, the packetizer 154 stores image data corresponding to the hierarchy N in the packet of a predetermined method from the acquired content (image data), and stores the image data. By supplying the stored packet to the communication unit 151, the packet is transmitted to the client 11 via the packet communication network 12. Details of the streaming process will be described later.

  Thus, the bit rate of the streaming data is determined based on the bit rate of the fastest writing speed among the writing speeds of the storage 102 transmitted from the client 11, so that the bit rate of the streaming data is It becomes faster than the bit rate of the storage 102, and the packet received as streaming data cannot be recorded in the storage 102 on the client 11 side. As a result, since the content can be used only by a specific legitimate user, unauthorized use of the content can be prevented.

  Next, details of the hierarchy determination processing in step S91 in FIG. 8 will be described with reference to the flowchart in FIG.

  In step S111, the hierarchy determining unit 152 determines whether a bit rate and a content name are received. For example, the communication unit 151 receives an RTSP packet transmitted from the client 11 and supplies the bit rate and content name stored in the received RTSP packet to the hierarchy determination unit 152. The hierarchy determining unit 152 determines whether or not the bit rate and the content name are received based on the bit rate and the content name supplied from the communication unit 151.

  If it is determined in step S111 that the bit rate and content name have not been received, the process returns to step S111 and the above-described processing is repeated until the communication unit 151 receives an RTSP packet storing the bit rate and content name. . That is, the server 13 stands by until an RTSP packet storing a bit rate and a content name is transmitted from the client 11 via the packet communication network 12.

  On the other hand, when it is determined in step S111 that the bit rate and the content name have been received, the process proceeds to step S112, and the hierarchy determining unit 152 sets hierarchy N = 1 as the initial value of the hierarchy determining process. For example, in step S112, when the hierarchy determining unit 152 receives a bit rate of 25 (Mbps) and a content name indicating “sport soccer” from the communication unit 151, as an initial value of the hierarchy determining process, Set layer N = 1.

  At this time, the bit rate is the bit rate of the maximum writing speed of the storage 102 of the client 11. In addition, although the content name indicates “sport soccer”, as described above, for example, the content “sport soccer” is recorded by the server 13 with the IP address “192.168.0.1”. Since it is the content of the file name “home / data / data.avi”, the information includes the file name “/home/data/data.avi”.

  In step S <b> 113, the hierarchy determination unit 152 reads out hierarchy information that is information indicating the bit rate of each hierarchy in the hierarchy encoding from the hierarchy information holding unit 153.

  FIG. 10 is a diagram illustrating an example of hierarchical information.

  In the example shown in FIG. 10, the first line indicates items, and the second and subsequent lines indicate respective bit rate values in each layer. The first column indicates “hierarchy N” and the second column indicates “bit rate”. The unit of “bit rate” is Bps (bits per second).

  In the example shown in FIG. 10, a bit rate of 10 (Mbps) is shown for layer N of “1”, and a bit of 20 (Mbps) for layer N of “2”. The rate is shown, the bit rate of 30 (Mbps) is shown for the layer N of “3”, and the bit rate of 40 (Mbps) is shown for the layer N of “4” ing.

  In other words, an example of the bit rate of each layer in this layer encoding is that of the first layer when the frame rate is 30 (fps) in a certain content (for example, “sport soccer”). The bit rate of the encoded data is 10 (Mbps), the bit rate of the encoded data of the second layer is 20 (Mbps), and the bit rate of the encoded data of the third layer is 30 (Mbps) ) And indicates that the bit rate of the encoded data of the fourth layer is 40 (Mbps).

  These hierarchical information may be stored in a table and stored.

  Returning to the flowchart of FIG. 9, for example, the hierarchy determining unit 152 receives 10 (Mbps), 20 (Mbps), and 30 (as the bit rates of the first to fourth encoded data from the hierarchy information holding unit 153. Hierarchy information (FIG. 10) indicating the bit rate of Mbps) and 40 (Mbps) is read.

  In step S <b> 114, the hierarchy determination unit 152 determines whether or not the bit rate of the hierarchy N exceeds the bit rate of the maximum write speed of the storage 102 of the client 11. If it is determined in step S114 that the bit rate of the hierarchy N does not exceed the bit rate of the maximum writing speed, the process proceeds to step S115, and the hierarchy determining unit 152 increments the hierarchy N by 1.

  For example, in step S114, the hierarchy determination unit 152 is 10 (Mbps) corresponding to the hierarchy N = 1, which is set as the initial value of the hierarchy determination process among the bit rates read from the hierarchy information holding unit 153. It is determined whether the bit rate exceeds the bit rate of 25 (Mbps) supplied from the communication unit 151. Since 10 (Mbps) does not exceed 25 (Mbps), the process proceeds to step S115, and the hierarchy is determined. The unit 152 increments the hierarchy N by 1 so that the hierarchy N = 2.

  In step S114, the hierarchy determination unit 152 is 20 (Mbps) corresponding to the hierarchy N = 2 set as the initial value of the hierarchy determination process among the bit rates read from the hierarchy information holding unit 153. It is determined whether the bit rate exceeds the bit rate of 25 (Mbps) supplied from the communication unit 151. Since 20 (Mbps) does not exceed 25 (Mbps), the process proceeds to step S115, and the hierarchy is determined. The unit 152 increments the hierarchy N by 1 so that the hierarchy N = 3.

  Furthermore, in step S114, the hierarchy determination unit 152 is 30 (Mbps) corresponding to the hierarchy N = 3, which is set as the initial value of the hierarchy determination process among the bit rates read from the hierarchy information holding unit 153. It is determined whether or not the bit rate exceeds a bit rate of 25 (Mbps) supplied from the communication unit 151. Since 30 (Mbps) exceeds 25 (Mbps), the process proceeds to step S116. .

  In step S116, the hierarchy determining unit 152 notifies the packetizer 154 of the hierarchy N, returns the process to step S91 in FIG. 9, and executes the processes after step S92. For example, in the process of step S114, the hierarchy determining unit 152 uses the packetizer 154 to indicate information indicating the hierarchy N = 3, which is a hierarchy in which the bit rate of the hierarchy N exceeds the bit rate of the maximum write speed of the storage 102 of the client 11. To supply.

  At this time, the hierarchy determining unit 152 supplies the content name supplied from the communication unit 151 to the packetizer 154. For example, the hierarchy determination unit 152 supplies the packetizer 154 with the content name indicating “sport soccer” supplied from the communication unit 151 (that is, the file name “/home/data/data.avi”).

  In this way, the bit rate of the maximum write speed of the storage transmitted from the client 11 and the bit rate of the hierarchically encoded data in the hierarchical information are sequentially compared, and the bit rate of the hierarchical N is the storage bit rate. In the case of exceeding the bit rate, the bit rate of the layer N is set to the bit rate of the streaming data, so that the content can be protected and the streaming data can be distributed at the optimum bit rate. Further, even when streaming delivery is performed to a plurality of clients 11, content can be delivered to each client 11 at an optimum bit rate.

  Next, details of the streaming processing in step S92 in FIG. 8 will be described with reference to the flowchart in FIG.

  In step S131, the packetizer 154 acquires the hierarchy N. For example, in step S131, the packetizer 154 acquires information indicating the hierarchy N = 3 supplied from the hierarchy determination unit 152.

  In step S132, the packetizer 154 determines whether the file has ended. For example, in step S132, the packetizer 154 determines the content recording unit based on the content name indicating “sport soccer” (file name “/home/data/data.avi”) supplied from the hierarchy determination unit 152. It is determined whether or not the file with the file name “/home/data/data.avi” for streaming playback of the content “Sports Soccer” recorded in 155 has ended.

  If it is determined in step S132 that the file has not ended, the process proceeds to step S133, and the packetizer 154 acquires hierarchically encoded data for one frame from the content recording unit 155. For example, in step S <b> 133, the packetizer 154 obtains content (image data) for one frame from the content (image data) that is “sport soccer” that is hierarchically encoded and recorded in the content recording unit 155. To do.

  By the way, in general, a moving image expresses a motion by quickly switching one by one of still images (frames). That is, the moving image is displayed by a predetermined frame that can express a motion. Similarly, motion is expressed in a hierarchically encoded frame.

  Next, an example of the relationship between hierarchical codes and frames will be described with reference to FIG.

  On the upper side of the example shown in FIG. 12, a frame displayed at a certain time is shown. Further, the horizontal direction in the figure represents the time axis, and as described by the arrow in the figure, time will be described as elapses from the left to the right in the figure. Further, the squares in the figure indicate frames, and one square indicates one frame. Furthermore, on the lower side of the example shown in FIG. 12, an example of a hierarchically encoded frame 201-1 is shown.

  In the example shown in FIG. 12, the content expresses a motion as a moving image by continuously displaying frames 201-1 to 201-30 (30 frames) per second.

  Also, how many frames are displayed per second can be determined according to the characteristics of the device used and the application program. For example, by increasing the frame rate (the number of frames displayed per second), the image quality of the displayed image can be made smoother. When the frame rate is lowered, the image quality is not smoothed, There is a possibility of dropping frames. Specifically, in the example shown in FIG. 12, the frame rate is 30 (FPS (Frame Per Second)). That is, each of the frames 201-1 to 201-30 is displayed every 1/30 seconds.

  Furthermore, the image quality of the displayed image also changes depending on how much data is flowed per second. For example, by increasing the bit rate, the image quality of the displayed image can be improved, and when the bit rate is decreased, the image quality may be deteriorated. Also, there is a trade-off relationship between the bit rate and the image quality of the displayed image. When the bit rate is increased, the data amount (file size) increases, and when the bit rate is decreased, the data amount (file size) decreases. Become.

  In the example shown in FIG. 12, each frame is hierarchically encoded. Therefore, as shown by the lower frame 201-1 in FIG. 12, the frame 201 has four layers of Laver1, Laver2, Laver3, and Laver4. The bit rates of each layer of Laver1, Laver2, Laver3, and Laver4 are 10 (Mbps), 20 (Mbps), 30 (Mbps), and 40 (Mbps).

  That is, in the example shown in FIG. 12, in a certain content, when the frame rate is 30 (fps), the bit rate of the hierarchically encoded data of the first layer, the hierarchical code of the first layer to the second layer The bit rate of the encoded data, the bit rate of the hierarchically encoded data of the first layer to the third layer, and the bit rate of the hierarchically encoded data of the first layer to the fourth layer are 10 (Mbps), respectively. , 20 (Mbps), 30 (Mbps), and 40 (Mbps).

  Thus, in the streaming distribution system 1, when the client 11 has a display with a low resolution and a CPU with a low processing capability, such as a mobile phone, the bit rate of the first layer that is 10 (Mbps) Select a lower bit rate, or conversely, if you have a high-resolution display and a high-performance CPU, such as a desktop computer, select the bit rate of the fourth layer, which is 40 (Mbps). Thus, by increasing the bit rate, it is possible to execute reception processing and display processing in accordance with the processing capability in various receiving apparatuses. In other words, it can be said that this hierarchical encoding enables simultaneous data distribution from one file data to receiving apparatuses having different capabilities.

  For example, MPEG4 or JPEG2000 is used for encoding the hierarchical code.

  Returning to the flowchart of FIG. 11, in step S <b> 134, the packetizer 154 acquires data corresponding to the acquired hierarchy N from the data for one frame acquired from the content recording unit 155. The packetizer 154 stores the data corresponding to the acquired layer N in a packet of a predetermined method, and supplies the packet storing the data corresponding to the layer N to the communication unit 151.

  For example, the packetizer 154 obtains information indicating the layer N = 3 acquired from the layer determination unit 152 from the layer-encoded image data of the content “sport soccer” acquired from the content recording unit 155. The image data of the bit rate which is 30 (Mbps) according to is acquired. The packetizer 154 stores the acquired bit rate image data of 30 (Mbps) in a packet of a predetermined method, and supplies the packet storing the image data of bit rate of 30 (Mbps) to the communication unit 151.

  In step S135, the communication unit 151 transmits the data (packet) supplied from the packetizer 154 to the client 11 via the packet communication network 12, and the process returns to step S132. For example, in step S135, the communication unit 151 stores the image data of the content “sport soccer” having a bit rate of 30 (Mbps) supplied from the packetizer 154 via the packet communication network 12. To the client 11.

  At this time, the server 13 transmits the streaming data of the content (moving image) that is “sports soccer” to the client 11 via the packet communication network 12, so that the streaming is started. In addition, until the file (“/home/data/data.avi”) for streaming playback of the content “sports soccer” recorded in the content recording unit 155 is completed, the process from step S132 to step S135 is performed. The process is repeated.

  In step S132, when the file for reproducing the content “sports soccer” by streaming ends, the process returns to step S92 in FIG. 8 and the process ends.

  Thus, the server 13 determines the bit rate of the streaming data to be distributed based on the bit rate of the maximum writing speed notified from the client 11. It becomes faster than the bit rate of the storage 102, and the packet received as streaming data cannot be recorded in the storage 102 on the client 11 side. As a result, it is possible to prevent the content from being illegally reproduced, so that the provider providing the content can provide a service for delivering the content with peace of mind.

  The series of processes described above can be executed by hardware, but can also be executed by software. When a series of processing is executed by software, a program constituting the software may execute various functions by installing a computer incorporated in dedicated hardware or various programs. For example, it is installed from a recording medium in a general-purpose personal computer or the like.

  As shown in FIG. 2, this recording medium is distributed to provide a program to a user separately from a computer, and includes a magnetic disk 51 (including a flexible disk) on which the program is recorded, an optical disk 52 (CD- It is not only composed of a package medium consisting of ROM (CD-Read Only Memory) and DVD), magneto-optical disk 53 (including MD (trademark)), semiconductor memory 54, etc., but also pre-installed in a computer It is configured by a ROM 32 in which a program is recorded provided to the user in a state, a hard disk included in the recording unit 38, or the like.

The program for executing the above-described series of processing is installed in a computer via a wired or wireless communication medium such as a local area network, the Internet, or digital satellite broadcasting via an interface such as a router or a modem as necessary. You may be made to do.

  In the present specification, the step of describing the program stored in the recording medium is not limited to the processing performed in chronological order according to the described order, but is not necessarily performed in chronological order. It also includes processes that are executed individually.

  Further, in this specification, the system represents the entire apparatus constituted by a plurality of apparatuses.

It is a block diagram which shows one Embodiment of the streaming delivery system to which this invention is applied. It is a block diagram which shows the example of a structure of a client. It is a block diagram which shows the structure of the function of a client. It is a block diagram which shows the structure of the function of a server. It is a flowchart explaining the process of the data transmission / reception by a client. It is a figure which shows the example of the RTSP packet which stores the bit rate of the maximum writing speed. It is a flowchart explaining the detail of the process of maximum writing speed determination. It is a flowchart explaining the process of the data transmission / reception by a server. It is a flowchart explaining the detail of a hierarchy determination process. It is a figure which shows the example of hierarchy information. It is a flowchart explaining the detail of a process of streaming. It is a figure which shows the example of the relationship between a hierarchical code and a frame.

Explanation of symbols

  1 streaming distribution system, 11 client, 12 packet communication network, 13 server, 31 CPU, 38 recording unit, 39 communication unit, 40 drive, 51 magnetic disc, 52 optical disc, 53 optical disc, 101 rate designation unit, 102-1, 102 -2 and 102 storage, 103 packet generation unit, 104 buffer, 105 decoder, 111 write speed acquisition unit, 112 maximum write speed calculation unit, 121 transmission unit, 122 reception unit, 151 communication unit, 152 layer determination unit, 153 layer information Holding unit, 154 packetizer, 155 content recording unit, 161 receiving unit, 162 transmitting unit

Claims (10)

In a communication system composed of a receiving device and a transmitting device,
The receiving device is:
A calculating means for calculating a first speed indicating the fastest writing speed among the writing speeds of the respective recording media;
First transmission means for transmitting the calculated first speed to the transmission device;
The transmitter is
Receiving means for receiving the first speed transmitted from the receiving device;
By comparing the received first rate with the second rate indicating the transfer rate for each layer in the hierarchically encoded data, higher quality is obtained from the lowest layer indispensable for decoding. Determining means for determining the highest hierarchy of the data to be transmitted among the hierarchy of data up to a higher hierarchy for decoding;
An acquisition means for acquiring the data of the hierarchy from the hierarchically encoded data based on the determined hierarchy;
And a second transmitting means for transmitting the acquired data of the hierarchy. In a receiving device that receives a packet transmitted from a transmitting device via a communication network,
A calculating means for calculating a first speed indicating the fastest writing speed among the writing speeds of the respective recording media;
Transmitting means for transmitting the calculated first speed to the transmitting apparatus. A receiving apparatus comprising: Generating the session control message protocol message by storing the calculated first rate in the session control message protocol message;
The receiving device according to claim 2, wherein the transmitting unit transmits the generated message to the transmitting device. In a receiving method for receiving a packet transmitted from a transmitting device via a communication network,
A calculation step of calculating a first speed indicating the fastest writing speed among the writing speeds to the respective recording media;
A transmission control step of controlling transmission of the calculated first speed to the transmission device. In a program for causing a computer to perform reception processing for receiving a packet transmitted from a transmission device via a communication network,
A calculation step of calculating a first speed indicating the fastest writing speed among the writing speeds to the respective recording media;
A transmission control step of controlling transmission of the calculated first speed to the transmission device. In a transmitting device that transmits a packet to a receiving device via a communication network,
Receiving means for receiving the first speed indicating the fastest writing speed among the writing speeds to the respective recording media transmitted from the receiving device;
By comparing the received first rate with the second rate indicating the transfer rate for each layer in the hierarchically encoded data, higher quality is obtained from the lowest layer indispensable for decoding. Determining means for determining the highest hierarchy of the data to be transmitted among the hierarchy of data up to a higher hierarchy for decoding;
An acquisition means for acquiring the data of the hierarchy from the hierarchically encoded data based on the determined hierarchy;
A transmission device comprising: transmission means for transmitting the acquired data of the hierarchy. When the second speed is higher than the first speed, the determining unit is configured to perform the decoding from the lowest layer indispensable for decoding to the higher layer for higher quality decoding. The transmission apparatus according to claim 6, wherein, among data hierarchies, the highest hierarchy of the data to be transmitted is determined. Storage means for storing the second speed for each layer of hierarchically encoded data;
The transmission device according to claim 6, wherein the determining unit determines the hierarchy by comparing the received first speed with the stored second speed. In a transmission method for transmitting a packet to a receiving device via a communication network,
A reception control step for controlling reception of the first speed indicating the fastest writing speed among the writing speeds to the respective recording media transmitted from the receiving device;
By comparing the received first rate with the second rate indicating the transfer rate for each layer in the hierarchically encoded data, higher quality is obtained from the lowest layer indispensable for decoding. A determination step of determining the highest hierarchy of the data to be transmitted among the hierarchy of the data up to a higher hierarchy for decoding;
An acquisition step of acquiring data of the hierarchy from the hierarchically encoded data based on the determined hierarchy;
A transmission control step for controlling transmission of the acquired data of the hierarchy. In a program for causing a computer to perform transmission processing for transmitting a packet to a receiving device via a communication network,
A reception control step for controlling reception of the first speed indicating the fastest writing speed among the writing speeds to the respective recording media transmitted from the receiving device;
By comparing the received first rate with the second rate indicating the transfer rate for each layer in the hierarchically encoded data, higher quality is obtained from the lowest layer indispensable for decoding. A determination step of determining the highest hierarchy of the data to be transmitted among the hierarchy of the data up to a higher hierarchy for decoding;
An acquisition step of acquiring data of the hierarchy from the hierarchically encoded data based on the determined hierarchy;
A transmission control step for controlling transmission of the acquired data of the hierarchy.

Images