JP2005252620A - Content transmitting device, contents receiver, content sending program, content reproducing program, content sending method, and content reproducing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a contents transmitting device for sending contents, without interrupting the reproduction of the contents at the receiving side, even if the transmission quality of a transmission line deteriorates or a temporary line breakdown occurs. <P>SOLUTION: The contents transmitting device 3 comprises means 33, 34 for coding contents into coded contents different in bit rate, a means 40 for storing the coded contents, a means 373 for setting the unit data quantity being a unit of data to be sent at once and the transmission timing of the data transmitted by the unit data quantity for each of the individual coded contents based on the bit rate, and a means 38 for transmitting the transmission data via a network 5 at the transmission timing set by the transmission setting means 373. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a technology for transmitting and playing back content, and more particularly to a technology for improving resistance to a failure in a transmission path for transmitting content.

  In recent years, the spread of broadband networks has been remarkable, and there is an active movement to distribute contents using the Internet. An IP (Internet Protocol) network represented by the Internet is a best-effort network, and arrival of transmitted information is not guaranteed. Also, the transmission bandwidth and transmission quality of a transmission path change from moment to moment, and when a transmission path failure such as a decrease in transmission band, transmission path error, or line disconnection occurs, playback of the content being transmitted is not possible. Interrupted or interrupted.

  Therefore, as a technique for improving the tolerance against a failure in a transmission path for transmitting contents and the like, a hierarchical coding transmission system has been put into practical use in satellite digital broadcasting. In this method, the broadcast station side modulates the video into high-quality information that requires a high transmission rate and basic information that can be transmitted at a low transmission rate, and transmits them simultaneously. When the transmission speed of the transmission path is reduced, the video can be reproduced without interruption by reproducing the video from the basic information.

  In addition, a voice communication device is disclosed that can transmit the content of a call of a speaker even when the line quality is deteriorated (see Patent Document 1). This device transmits the encoded voice data obtained by encoding the voice of the talker and the character string data obtained by voice recognition of the voice of the talker at the same time. The content of the call can be transmitted.

  Furthermore, the carousel transmission method adopted in satellite digital broadcast data broadcasting allows the receiver to receive data normally even if the transmission quality of the transmission path temporarily decreases by repeatedly transmitting the same information. Is.

  Further, a data transmission system is disclosed in which data transmission / reception is not interrupted even when an abnormality occurs in a transmission line (see Patent Document 2). This system has a plurality of transmission paths with independent transmission forms such as satellite lines, dedicated lines, public telephone lines, etc., and when the transmission quality of any one of the transmission lines deteriorates, the data is transmitted by other transmission lines. The desired transmission quality can be ensured by transmitting / receiving.

Furthermore, a moving image playback device is disclosed in which the display screen of the receiver does not stop even if the transmission quality of the transmission path for transmitting the content deteriorates (see Patent Document 3). In this apparatus, content data and additional data (CM data) transmitted simultaneously from the content distribution server are received and stored. If the transmission quality deteriorates and the content data cannot be reproduced, it is stored. By reproducing the added data, the display screen can be prevented from being stopped.
JP2003-32382A (paragraph numbers 0005 to 0021) JP 2002-64515 A (paragraph numbers 0011 to 0049) JP 2003-46923 A (paragraph numbers 0014 to 0049)

  However, in the hierarchical coded transmission method, content for a certain period of time is transmitted at the same time. Therefore, if the transmission path is temporarily disconnected, the encoded content of all layers cannot be transmitted, and the content is reproduced at the receiver. Will be interrupted.

  Similarly, in the apparatus of Patent Document 1, since the voice of the sender and the character string data obtained by voice recognition of the voice are simultaneously transmitted, when the transmission path is temporarily disconnected, the apparatus of the receiver Cannot receive both the voice and character string data sent at that time, and cannot transmit the content of the call. Furthermore, in this apparatus, since character string data is displayed as subtitles, characteristics such as a speaker's way of speaking and voice are lost.

  In addition, the carousel transmission method repeatedly transmits the same information. However, since content transmission requires transmission of media that changes from moment to moment, transmission of content using the carousel transmission method may result in transmission depending on the time of day. The contents to do will become old. Moreover, since the information which became old is transmitted, the use efficiency of a transmission line falls.

  Further, the system disclosed in Patent Document 2 requires a plurality of lines such as a satellite line, a dedicated line, and a public telephone line, which causes a problem that the cost is excessive.

  Further, in the apparatus of Patent Document 3, when a failure occurs in the transmission path, it is possible to prevent the display screen from being stopped by reproducing the additional data. The content data cannot be received, and the reproduction of the content is interrupted.

  The present invention has been made to solve the above-described problems of the prior art, and interrupts the reproduction of content on the receiving side even when the transmission quality of the transmission line deteriorates or the line is temporarily disconnected. It is an object of the present invention to provide a content transmission device, a content reception device, a content transmission program, a content reproduction program, a content transmission method, and a content reproduction method that can be transmitted without any problem.

  In order to solve the above-described problem, the content transmission device according to claim 1 is a content transmission device that encodes content and transmits the content via a network, and includes an encoding unit, an encoded content storage unit, and a transmission The configuration includes a setting unit and a code transmission unit.

  According to such a configuration, the content transmission apparatus encodes the content into encoded content having different bit rates by the plurality of encoding units, and stores the encoded content in the encoded content storage unit. In addition, the transmission setting means, for each encoded content, based on the bit rate, a unit data amount that is a unit of transmission data that is transmitted at a time, and a transmission timing of transmission data that is transmitted for each unit data amount And set. Further, the transmission data is transmitted by the code transmission means via the network at the transmission timing set by the transmission setting means.

  Thus, the content transmitting apparatus can encode the content into a plurality of encoded contents having different bit rates, and transmit the encoded contents for each unit data amount at the transmission timing set for each encoded content. it can.

  Further, the content transmission device according to claim 2 is the content transmission device according to claim 1, wherein the content transmission device specifies a part or all of a retransmission section of the encoded content on a time axis of the reproduction time of the content. Based on the control information, it comprises a transmission number setting means for setting the number of transmissions for transmitting a part or all of the encoded content corresponding to the retransmission section, the transmission setting means for each encoded content, Based on the bit rate, the retransmission interval, and the number of times of transmission, the interval on the time axis of transmission data transmitted by the code transmission means and the transmission timing are set, and the code transmission means, The transmission data corresponding to the section set by the transmission setting unit is transmitted at the transmission timing.

  As a result, the content transmission apparatus can transmit a part or all of the encoded content corresponding to the designated retransmission section in an overlapping manner based on the transmission control information.

  Here, the transmission control information designates a part or all of the encoded content on the time axis of the content reproduction time as a retransmission interval to be transmitted redundantly by the code transmission means.

  Further, the content transmission device according to claim 3 is the content transmission device according to claim 1 or 2, wherein the content transmission device is set by the transmission setting unit based on network information indicating a failure of the network. The network monitoring means for delaying the transmission timing when a network failure occurs until after the failure is solved is adopted.

  As a result, based on the network information indicating the failure of the network, the content transmission device can transmit the encoded content when transmission is possible, without performing transmission when transmission of the encoded content is impossible. . The network information indicates, for example, data transmission restriction information transmitted by a network provider and performed when a network congestion occurs.

  A content transmission apparatus according to claim 4 is a content transmission apparatus that encodes content and transmits the encoded content via a network, the encoding means, the voice recognition means, the encoded content storage means, and the transmission The configuration includes a setting unit and a code transmission unit.

  According to this configuration, the content transmission apparatus encodes the content by the encoding unit to obtain encoded content, and the voice recognition unit recognizes the audio data included in the content as audio recognition data. Then, the encoded content and the voice recognition data are stored in the encoded content storage means.

  Further, the transmission setting means, based on the respective bit rates of the encoded content and the speech recognition data stored in the encoded content storage means, a unit data amount as a unit of transmission data to be transmitted at a time, and this unit The transmission timing of transmission data transmitted for each data amount is set. In addition, the transmission data is transmitted by the code transmission means via the network at the transmission timing set by the transmission setting means.

  Thus, the content transmitting apparatus transmits the encoded content obtained by encoding the content, and the voice recognition data obtained by voice recognition of the voice data included in the content, to the transmission timing set for each of the encoded content and the voice recognition data. Can be transmitted for each unit data amount.

  Furthermore, the content receiving device according to claim 5 receives the encoded content obtained by encoding the same content into a plurality of bit rates from the content transmitting device according to any one of claims 1 to 3. The content receiving apparatus for reproducing the content includes a receiving unit, a decoding unit, a decoded data storage unit, a reception state determination unit, a decoded data selection unit, and a decoded data output unit. .

  According to such a configuration, the content receiving device receives the transmission data constituting the encoded content by the receiving unit. Further, the transmission data is decoded by the decoding means to be decoded data. Further, the decoded data is stored in the decoded data storage means. Further, the reception state determination means determines the loss of the decoded data constituting the content for each decoded data.

  Further, the decoded data selecting means selects the decoded data with the highest bit rate from among the decoded data stored in the decoded data storage means based on the determination result of the loss determined by the reception state determining means, and the decoded data The output means outputs the decoded data selected by the decoded data selection means.

  Thus, the content receiving apparatus receives and decodes transmission data constituting a plurality of encoded contents having different bit rates, and among the decoded decoded data, the decoded data with the highest bit rate, that is, the highest quality is obtained. High data can be output.

  Note that the loss of the decoded data constituting the content indicates that the decoded data corresponding to a part of the entire content is not stored in the decoded data storage means for each bit rate of decoded data. This occurs because some transmission data is not received due to a road fault or the like.

  Further, the content receiving device according to claim 6 is the content receiving device according to claim 5, further comprising: a decryption state determination unit that determines a decryption state of the decrypted data decrypted by the decryption unit; The means is configured to select the decoded data having the highest bit rate from among the decoded data stored in the decoded data storage means and determined to have been normally decoded by the decoding state determination means.

  As a result, the content receiving apparatus can determine the decryption state of the decrypted data and output the decrypted data having the highest bit rate among the decrypted data that has been decrypted normally.

  Furthermore, the content receiving device according to claim 7 receives, from the content transmitting device according to claim 4, encoded content obtained by encoding the content and speech recognition data obtained by performing speech recognition on the audio data of the content. A content receiving apparatus for reproducing the content, wherein the receiving means, the decoding means, the decoded data reception state determining means, the speech synthesizing means, the synthesized voice data receiving state determining means, the decoded data storage means, The decoded data selecting means and the decoded data output means are provided.

  According to such a configuration, the content receiving apparatus receives the transmission data constituting the encoded content obtained by encoding the content and the voice recognition data obtained by voice recognition of the audio data of the content by the receiving unit. In addition, the transmission data constituting the encoded content is decoded by the decoding means to obtain decoded data. Further, the decrypted data reception state determining means determines the lack of content for the decrypted data.

  Further, transmission data constituting the speech recognition data is synthesized by speech synthesis means to produce synthesized speech data, and the synthesized speech data reception state judgment means judges whether the synthesized speech data is missing from the content. Also, the decoded data and the synthesized voice data are stored in the decoded data storage means.

  Further, based on the determination result of the loss determined by the decoded data selection means and the synthesized voice data reception status determination means by the decoded data selection means, the decoded data and synthesized voice data stored in the decoded data storage means Among them, the data with the highest bit rate is selected, and the decoded data output means outputs the data selected by the decoded data selection means.

  Thus, the content receiving apparatus can receive the encoded content and the speech recognition data, decode the encoded content, and synthesize the speech based on the speech recognition data. And the data of the highest bit rate can be output among the decoded data and synthetic | combination audio | voice data memorize | stored in the decoded data storage means.

  The content transmission method according to claim 8 is a content transmission method in which content is encoded and transmitted via a network, and includes an encoding step, an encoded content storage step, a transmission setting step, A transmission step.

  According to this method, the content is encoded into a plurality of encoded contents having different bit rates by the encoding step, and then the encoded content encoded in the encoding step is encoded by the encoded content storage step. Store in the content storage device. Then, in the transmission setting step, for each encoded content, based on the bit rate, a unit data amount that is a unit of transmission data that is transmitted at a time, and a transmission timing of transmission data that is transmitted for each unit data amount And set. Further, in the code transmission step, this transmission data is transmitted via the network at the transmission timing set by the transmission setting means.

  As a result, the content can be encoded into encoded content having different bit rates, and transmitted for each unit data amount at the transmission timing set based on the bit rate.

  Furthermore, the content reproduction method according to claim 9 receives encoded content obtained by encoding the same content into a plurality of bit rates from the content transmission device according to any one of claims 1 to 3. A content playback method for playing back the content, including a reception step, a decryption step, a decryption data storage step, a reception state determination step, a decryption data selection step, and a decryption data output step. And

  According to this method, the transmission data constituting the encoded content is received in the reception step, and then the transmission data is decoded into the decoded data in the decoding step. Then, in the decoded data storage step, the decoded data decoded in the decoding step is stored in the decoded data storage device. Further, the lack of the decoded data constituting the content is determined for each decoded data decoded in the decoding step by the reception state determination step, and the determination of the loss determined in the reception state determination step by the decoded data selection step Based on the result, the decoded data having the highest bit rate is selected from the decoded data stored in the decoded data storage device. Then, in the decoded data output step, the decoded data selected in the decoded data selection step is output.

  Accordingly, transmission data constituting a plurality of encoded contents having different bit rates can be received and decoded, and decoded data having the highest bit rate among the decoded data can be output.

  The content transmission program according to claim 10 causes a computer to function as an encoding unit, a transmission setting unit, and a code transmission unit in order to encode the content and transmit it via a network.

  According to such a configuration, the content transmission program encodes the content into encoded content having different bit rates by a plurality of encoding units, and stores the encoded content in the encoded content storage device. In addition, the transmission setting means, for each encoded content, based on the bit rate, a unit data amount that is a unit of transmission data that is transmitted at a time, and a transmission timing of transmission data that is transmitted for each unit data amount And set. Furthermore, the transmission data is transmitted by the code transmission means via the network at the transmission timing set by the transmission setting means.

  As a result, the content transmission program can encode the content into encoded content having different bit rates and transmit the encoded content for each unit data amount at the transmission timing set for each encoded content.

  The content reproduction program according to claim 11 receives encoded content obtained by encoding the same content into a plurality of bit rates from the content transmission device according to any one of claims 1 to 3. In order to reproduce the content, the computer is caused to function as a receiving unit, a decoding unit, a reception state determining unit, and a decoded data output unit.

  According to such a configuration, the content reproduction program receives the transmission data constituting the encoded content by the receiving unit, decodes the transmission data by the decoding unit, and stores the decoded data in the decoded data storage device. . Further, the reception state determination means determines the loss of the decoded data constituting the content for each piece of decoded data, and the decoded data selection means decodes based on the determination result of the loss determined by the reception state determination means. Of the decoded data stored in the data storage device, the decoded data with the highest bit rate is selected. Further, the decoded data output means outputs the decoded data selected by the decoded data selection means.

  Thus, the content reproduction program can receive and decode transmission data constituting a plurality of encoded contents having different bit rates, and output decoded data with the highest bit rate among the decoded data.

  The content transmission device, content reception device, content transmission method, content reproduction method, content transmission program, and content reproduction program according to the present invention have the following excellent effects.

  According to the invention of claim 1, claim 8 or claim 10, since the unit data amount and the transmission timing are set for each encoded content, the content playback time is set to a certain section on the time axis. A plurality of transmission data having different bit rates, including corresponding content data, can be transmitted at different times. For this reason, even when a transmission line is temporarily faulty at a certain time and the transmission data transmitted at this time is not normally transmitted, other data including content data corresponding to that section at a different time Since bit rate transmission data is transmitted, tolerance against failures can be increased.

  In addition, when the encoded content is continuously transmitted for each unit data amount corresponding to a short section on the time axis of the content reproduction time, the amount of information that cannot be transmitted as the failure occurs for a longer time However, the amount of information that cannot be transmitted is reduced even if it occurs frequently for short-time failures. On the other hand, when intermittent transmission is performed for each unit data amount corresponding to a long section, even if a failure occurs in a relatively continuous time, if the transmission timing does not match the failure occurrence, the failure will occur. Regardless of the fact that all the information can be transmitted, if the transmission timing and the occurrence of the failure coincide, even if the failure is a short time, the information corresponding to the long section will not be transmitted. Weakness to time obstacles. Therefore, encoded content at a certain bit rate is continuously transmitted for each unit data amount corresponding to a short interval on the time axis, and encoded content at a certain bit rate corresponds to a long interval. By intermittently transmitting data for each unit data amount, it is possible to increase tolerance against relatively continuous failures (burst errors) as well as frequent short-term failures (random errors). Can do.

  According to the second aspect of the present invention, for example, when a section determined to be high in importance by a content producer or the like is input from outside as transmission control information designated as a retransmission section, the retransmission section It is possible to set a large number of transmissions of part or all of the encoded content corresponding to, and to transmit them in duplicate. Therefore, the content receiving apparatus can receive the content data corresponding to the section with high importance with a higher probability, and a part of the section with high importance instead of the entire content. As part of the encoded content corresponding to, the number of transmissions is increased so that old data and relatively unimportant data are not transmitted many times as in the carousel transmission method, while efficiently transmitting In addition, it is possible to improve resistance to transmission path failures.

  According to the third aspect of the present invention, when a network failure is detected, transmission of transmission data is delayed and transmitted after the failure is resolved, thereby improving resistance to a transmission path failure.

  According to the fourth aspect of the present invention, the unit data amount and the transmission timing are set for the encoded content and the speech recognition data, respectively, and the data corresponding to a certain section on the time axis of the content reproduction time is different. Can be sent at time. Furthermore, the voice recognition data is data having a lower bit rate than encoded content obtained by encoding moving image data and audio data. Therefore, even when the transmission path band is reduced and the transmission data of the encoded content is not normally transmitted, the speech recognition data including the audio information of the content is transmitted, and the audio information is interrupted in the device that receives the content. Without receiving.

  According to the invention of claim 5, claim 9 or claim 11, there is a temporary failure in the transmission path at a certain time, and the transmission data transmitted from the content transmitting device at this time cannot be received. Even in such a case, transmission data of other bit rates including content data corresponding to a section on the time axis of the reproduction time of the content can be received at different times, so that the content is not interrupted. Can be output.

  According to the sixth aspect of the present invention, since the decoded data that failed to be decoded is not output, the decoded data having the highest bit rate among the decoded data that has been normally decoded is output as the reproduction content. Content can be output.

  According to the seventh aspect of the present invention, even when the transmission path band is reduced and the transmission data of the encoded content is not normally transmitted, the voice recognition data having a lower bit rate than the encoded content is continuously received. Can be synthesized and output the audio data of the content.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Content transmission system configuration]
With reference to FIG. 1, the structure of the content transmission system 1 which is embodiment of this invention is demonstrated. FIG. 1 is a block diagram showing a configuration of a content transmission system 1 according to the present invention. The content transmission system 1 is a system for transmitting content from a content transmission device 3 that is a content distributor device to a content reception device 7 that is a content viewer device via the network 5. is there.

  The content transmission device 3 encodes the content and transmits it to the content reception device 7 via the network 5.

  Each of the content receiving devices 7 receives encoded content transmitted from the network 5 from the content transmitting device 3 and reproduces it. The content receiving device 7 may relay the reproduced content to another network (not shown) and retransmit it to another viewer's terminal (not shown).

  Hereinafter, the content transmission apparatus 3 that encodes and transmits content in the content transmission system 1 and the content reception apparatus 7 that receives the encoded content from the content transmission apparatus 3 and reproduces the content will be described in detail.

(Configuration of content transmission device)
First, the configuration of the content transmission device 3 will be described with reference to FIG. FIG. 2 is a block diagram showing the configuration of the content transmission device 3 in the present invention. The content transmission apparatus 3 includes a content input unit 31, a voice recognition unit 32, a medium bit rate encoding unit 33, a high bit rate encoding unit 34, a transmission control information input unit 35, and a network information input unit 36. A transmission control unit 37, a code transmission unit 38, a communication transmission / reception unit 39, an encoded content storage unit 40, and a transmission setting information storage unit 41.

  The content input means 31 inputs content to be distributed from the outside. The content input here is, for example, multimedia content composed of video, audio, characters, graphics, and the like. The content input here is output to the speech recognition means 32, the medium bit rate encoding means 33, and the high bit rate encoding means 34.

  The voice recognition means 32 is for voice recognition of the voice data of the content input from the content input means 31. The speech recognition data recognized here is stored in the encoded content storage means 40 as low bit rate encoded content. The low bit rate encoded content (speech recognition data) includes, for example, text data obtained by speech recognition of speech data included in the content, and supplementary information for speech synthesis such as phonemes in addition to the text data. Alternatively, it may be data for speech synthesis that does not include text data.

  Here, the low bit rate encoded content is more relative to the medium bit rate encoded content and the high bit rate encoded content encoded by the medium bit rate encoding means 33 and the high bit rate encoding means 34 described later. Therefore, it is assumed that the data has a low bit rate. Furthermore, the medium bit rate encoded content is encoded content having a relatively lower bit rate than the high bit rate encoded content.

  The medium bit rate encoding means (encoding means) 33 encodes the content input from the content input means 31 by a predetermined encoding method. The medium bit rate encoded content encoded here is stored in the encoded content storage means 40.

  The high bit rate encoding means (encoding means) 34 encodes the content input from the content input means 31 by a predetermined encoding method. The high bit rate encoded content encoded here is stored in the encoded content storage means 40.

  A general encoding method can be used as the encoding method in these encoding means 33 and 34. For example, if the content is video data, VRML (Virtual Reality Modeling Language) or TVML (TV programming Making) that encodes information necessary for waveform coding and CG (Computer Graphic) synthesis by the content receiving device 7 is used. Language) or the like can be used. Also, not only waveform coding but also synthetic coding such as CELP (Code Excited Linear Prediction) coding may be used for audio data.

  Also, the encoding means 33 and 34 may be encoded into encoded contents having different bit rates by the same encoding method, or may be encoded by different encoding methods. At this time, for example, waveform encoding is applied to high bit rate encoding, and composite encoding is applied to low bit rate encoding, such as code corresponding to the bit rate of the encoded content to be generated. By using the encoding method, not only a high bit rate but also a low bit rate encoded content can be encoded without impairing the content. For this reason, there is no problem that the degree of information transmission such as degradation in viewing quality and resolution is significantly lowered when encoding at an extremely low bit rate, which occurs in the hierarchical coding transmission system.

  Note that here, the content transmission apparatus 3 includes two encoding units 33 and 34 that encode the same content into encoded content of different bit rates, and a voice recognition unit 32 that recognizes the audio data of the content. However, the content transmission apparatus 3 of the present invention includes at least two encoding units for encoding encoded content of different bit rates, or at least one encoding unit and at least one voice recognition unit. Any configuration may be used.

  The transmission control information input means 35 inputs transmission control information indicating a retransmission section in which part or all of the content is transmitted in an overlapping manner from the outside. The transmission control information input here is output to the transmission count setting unit 372 of the transmission control unit 37.

  The network information input unit 36 inputs network information indicating a failure of the network 5 from the outside. The network information input here is output to the network monitoring unit 374 of the transmission control unit 37.

  The transmission control unit 37 sends the encoded content (low bit rate encoded content, medium bit rate encoded content, and high bit rate encoded content) stored in the encoded content storage unit 40 to the code transmission unit 38. Control to transmit is performed. Here, the transmission control unit 37 includes a code monitoring control unit 371, a transmission count setting unit 372, a transmission setting unit 373, and a network monitoring unit 374.

  The code monitoring control unit 371 monitors the data amount of each encoded content stored in the encoded content storage unit 40 and is stored in the encoded content storage unit 40 input from the network monitoring unit 374 described later. Unnecessary data is erased from the encoded content storage means 40 based on the notification of the data transmission. The data amount of each encoded content stored in the encoded content storage unit 40 acquired here is output to the transmission setting unit 373.

  Here, the code monitoring control unit 371 receives the retransmission interval set by the transmission number setting unit 372 described later and the number of transmissions of a part of the encoded content corresponding to the interval, and the code transmission unit described later. Each time the section on the time axis of the playback time of the content of the transmission data transmitted by 38 is notified from the network monitoring means 374, the number of transmissions is measured for the encoded content corresponding to that section. When a certain section of the encoded content stored in the encoded content storage means 40 is transmitted for the number of transmissions set by the transmission count setting means 372, data corresponding to this section is stored in the encoded content storage. It was decided to delete from the means 40. Furthermore, here, the code monitoring control unit 371 replays a part of the encoded content stored in the encoded content storage unit 40 on the time axis of the reproduction time of the content, that is, the number of transmissions. The reproduction start time of a part of the encoded content that has not been transmitted by the number of transmissions set by the setting unit 372 is used as the start time of the section of transmission data to be transmitted next by the code transmission unit 38 to the transmission data setting unit 373a. I decided to notify.

  The transmission count setting unit 372 sets the number of transmissions of the encoded content to be transmitted to the code transmission unit 38 based on the transmission control information input from the transmission control information input unit 35. The number of transmissions set here is output to the transmission setting means 373. Note that the transmission control information indicates a retransmission interval for redundant transmission.

  Here, referring to FIG. 3 (see FIG. 2 as appropriate), the retransmission interval designated by the content distributor (producer) and the importance of the data corresponding to this interval determined by the distributor are determined. An example in which the transmission count setting unit 372 sets the transmission count based on the transmission control information shown will be described. FIG. 3 is an explanatory diagram showing an example of transmission control information indicating the retransmission interval and the importance of data corresponding to the interval. In FIG. 3, for convenience of explanation, a line number is given to the left side of the transmission control information.

  In FIG. 3, the number on the left side of each row indicates “minute: second: frame” corresponding to the playback time from the start when the content is played back, and the number on the right side indicates the next row from the frame described on the left side. The importance of the data corresponding to the section up to the frame shall be indicated. The importance is specified by an integer from 0 to 4, with 4 indicating the most important and 0 indicating relatively unimportant. For example, in the transmission control information shown in FIG. 3, (1) “00:00:00” on the line, “1” on the right side thereof, and (2) “02:00:02” on the right side. In addition, it is shown that the importance level from 0 frame to 2 minutes 0 seconds 2 frames at the start of content reproduction (after 0 minutes 0 seconds has elapsed from the start) is “1”. Further, from the description of “02:00:02” on the (2) line and “2” on the right side of the line, and “05:00:02” on the (3) line, 2 minutes 0 seconds 2 frames to 5 It is shown that the degree of importance up to 2 frames per minute 0 second is “2”.

  Here, it is assumed that the transmission control information shown in FIG. 3 is input from the transmission control information input means 35 to the transmission count setting means 372. Then, the transmission count setting means 372 sets the transmission count of data corresponding to the designated section based on the importance of the transmission control information. Here, for example, the number of times that the importance number is duplicated is indicated. That is, when the importance is “0”, the number of times of duplication is 0 and the number of transmissions is one. Similarly, when the importance is “1”, the number of transmissions is two and the importance is “2”. If the importance is “3”, it is set to 4 times, and if the importance is “4”, it is set to 5 times.

  Therefore, based on the transmission control information in FIG. 3, the transmission count setting means 372 sets the transmission count twice, 2 times for data in the section from 0 minutes 0 seconds 0 frames to 2 minutes 0 seconds 2 frames from the start of the content. The number of transmissions is set to 3 for data in the interval from minute 0 second 2 frames to 5 minutes 0 seconds 2 frames.

  In this example, the transmission control information describes a retransmission section in which part or all of the content is transmitted in duplicate, and the importance (in the case of importance 1 to 4) corresponding to the number of transmissions, and further The non-overlapping section and its importance (in the case of importance 0) are also described, but the transmission control information specifies the retransmission section, and the transmission count setting means 372 corresponds to the specified section based on it. It is only necessary to be able to set the number of data transmissions to be performed.

  For example, in the transmission control information, only a retransmission section having the number of transmissions of 3 times or more and a data indicating the number of transmissions are described, and the transmission number setting means 372 transmits data corresponding to the retransmission section described in the transmission control information. May set the number of transmissions indicated in the transmission control information, and may set the number of transmissions to 2 for data corresponding to other sections. Further, only the retransmission interval is described in the transmission control information, and the transmission count setting means 372 sets the transmission count to 2 for the data corresponding to the retransmission interval described in the transmission control information, The corresponding data may be determined not to overlap and the number of transmissions may be set to one.

  Returning to FIG. 2, the description will be continued. The transmission setting unit 373 transmits the transmission data (packets) to be transmitted at once for each encoded content stored in the encoded content storage unit 40 on the time axis of the reproduction time of the content, and the transmission data The transmission timing is set. Here, the transmission setting unit 373 includes a transmission data setting unit 373a and a transmission timing setting unit 373b.

  The transmission data setting unit 373a sets the unit data amount of transmission data of each encoded content based on the bit rate of each encoded content stored in the encoded content storage unit 40, and the unit data amount and the number of transmissions The transmission data section is set based on the retransmission section input from the setting means 372 and the number of times of data transmission corresponding to the section. The section of transmission data set here is output to the transmission timing setting unit 373b.

First, a method will be described in which the transmission data setting unit 373a sets the unit data amount of the encoded content of the three types of bit rates stored in the encoded content storage unit 40. Here, the transmission data setting unit 373a, based on the equation (1) to (3) shown below, by the ratio of the transmission path band T _w and bit rate T _r of each of the encoded content, and transmits at once The unit data amount of the transmission data unit is set by the time width D.

When (T _r / T _w ) <T ₁ D = n ₃ d (1)
When T ₁ ≦ (T _r / T _w ) <T ₂ D = n ₂ d (2)
When T ₂ ≦ (T _r / T _w ) D = n ₁ d (3)

Here, the time width D is a time width of the reproduction time of the transmission data when the content is reproduced. Further, threshold values T ₁ , T ₂ (T ₁ <T ₂ ), n ₁ , n ₂ , n ₃ (n ₁ <n ₂ <n ₃ ) and transmission unit time d are set in transmission setting information storage means 41 to be described later. Are registered in advance. Then, when transmitting encoded content in a transmission line (network 5) of a certain transmission line band, the encoded content corresponding to the equation (1) has a relatively low bit rate with respect to the transmission line band, The encoded content corresponding to Expression (3) has a relatively high bit rate with respect to the transmission path band. Encoded content having a relatively low bit rate with respect to the transmission path band can reduce the unit data amount even if the time width D is increased, so that data with a large time width D can be transmitted all at once. Encoded contents having a relatively high bit rate with respect to the path band must be transmitted frequently with a small time width D so that the amount of transmission data per time does not exceed the transmission path band. In addition, it is preferable to use the optimal value calculated | required beforehand by simulation etc. for this threshold value and unit time.

  Next, a description will be given of a method in which the transmission data setting unit 373a sets sections of transmission data to be transmitted at a time for encoded content at a certain bit rate.

  Here, whenever the transmission start time on the time axis of the reproduction time of the content of the transmission data to be transmitted next is input from the code monitoring control unit 371, the transmission data setting unit 373a sets this time as the transmission data. And a transmission data section having a time width D or a time width shorter than the time width D from the start time is set. Then, the transmission data setting unit 373a starts the transmission unit time from the start time so that the order of the sections of the transmission data transmitted in order by the code transmission unit 38 is not changed on the time axis of the reproduction time of the content. With respect to the time interval d, the transmission data interval is repeatedly set until the number of transmissions set by the transmission number setting means 372 is reached.

  Here, referring to FIG. 4 (see FIG. 2 as appropriate), when the retransmission interval and the number of transmissions are input from transmission number setting means 372, transmission data setting unit 373a performs encoded content of a certain bit rate. An example of setting a section of transmission data to be transmitted at once will be described. FIG. 4 is an explanatory diagram schematically illustrating an example in which the transmission data setting unit 373a sets the transmission data section of the encoded content. The transmission data section setting method described here is merely an example, and the transmission data section setting method in the content transmission apparatus 3 of the present invention is not limited to this.

  It should be noted that the time width D is determined to be 4d by the above method, and, further, as shown in FIG. 4, from the transmission number setting means 372, the interval from the reproduction time 3d to 8d is the retransmission interval, the reproduction interval is 2 Assume that it is notified that the interval from time 8d to 10d is the retransmission interval with the number of transmissions of 4, and the interval from reproduction time 10d to 13d is the retransmission interval with the number of transmissions of 2. Here, it is assumed that the transmission data setting unit 373a has already set the section j0 from the reproduction time 1d to 5d as the transmission data section to be transmitted first.

  Here, first, the transmission data setting unit 373a receives the start time of the transmission data to be transmitted next from the code monitoring control unit 371 on the time axis of the reproduction time of the content. Here, it is assumed that the reproduction time 3d is input by the code monitoring control unit 371 as the start time. Therefore, the transmission data setting unit 373a sets the start time of the section of transmission data to be transmitted next as the reproduction time 3d.

  The transmission data setting unit 373a changes in the number of transmissions set by the transmission number setting unit 372 in the section from the reproduction time 3d to the time width D (4d), that is, the section from the reproduction time 3d to 7d. Determine whether. Here, since the number of transmissions is set to 2 in the section from the playback time 3d to 7d, the transmission data setting unit 373a determines that there is no change in the number of transmissions in this section. If there is no change in the number of transmissions, or if the number of transmissions increases as the playback time elapses, even if this interval is set as the interval of transmission data, It is possible to set so that the order of data sections and playback times are not interchanged. Therefore, the transmission data setting unit 373a sets a section j1 from the reproduction time 3d to 7d in which the time width of the transmission data is 4d as the transmission data section.

  Subsequently, the transmission data setting unit 373a sets the number of transmissions set by the transmission number setting means 372 for the section of the time width from the reproduction time 3d to the transmission unit time d, that is, the section from the reproduction time 3d to 4d. It is determined whether a transmission data section is set. Here, in the section from the reproduction time 3d to 4d, the number of transmissions is set to 2 by the transmission number setting means 372, and two transmission data of the section j0 and the section j1 including this section are set. Therefore, the transmission data setting unit 373a determines that the transmission data is set for the number of transmissions in the section from the reproduction time 3d to 4d, that is, all the transmission data having the reproduction time 3d as the start time is set.

  Furthermore, when the reproduction time 5d is input from the code monitoring control unit 371 as the start time of transmission data to be transmitted next, the transmission data setting unit 373a sets the start time of the section of transmission data to be transmitted next. The playback time is set to 5d. Then, the transmission data setting unit 373a determines whether there is a change in the number of transmissions set by the transmission number setting means 372 in the section from the reproduction time 5d to the time width 4d, that is, the section from the reproduction time 5d to 9d. To do. Here, since the number of transmissions is set to 2 in the section from the playback time 5d to 8d, and the number of transmissions is set to 4 in the section from the playback time 8d to 9d, the transmission data setting unit 373a transmits in this section. Judge that the number of times has increased. Therefore, the transmission data setting unit 373a sets a section j2 from the reproduction time 5d to 9d where the time width of the transmission data is 4d as the transmission data section.

  Subsequently, the transmission data setting unit 373a sets the number of transmissions set by the transmission number setting unit 372 for the section of the time width from the reproduction time 5d to the transmission unit time d, that is, the section from the reproduction time 5d to 6d. It is determined whether a transmission data section is set. Here, in the section from the reproduction time 5d to 6d, the number of transmissions is set to 2 by the transmission number setting means 372, and two transmission data of the section j1 and the section j2 including this section are set. Therefore, it is determined that the transmission data is set for the number of transmissions in the section from the reproduction time 5d to 6d.

  In addition, when the reproduction time 7d is input from the code monitoring control unit 371 as the start time of transmission data to be transmitted next, the transmission data setting unit 373a sets the start time of the section of transmission data to be transmitted next. The playback time is set to 7d. Then, the transmission data setting unit 373a determines whether there is a change in the number of transmissions set by the transmission number setting unit 372 in the section from the reproduction time 7d to the time width 4d, that is, from the reproduction time 7d to 11d. To do. Here, the number of transmissions is set to 2 in the section from the playback time 7d to 8d, the number of transmissions is set to 4 in the section from the playback time 8d to 10d, and the number of transmissions is set to 2 in the section from the playback time 10d to 11d. Therefore, the transmission data setting unit 373a determines that the number of transmissions has increased in this section and then decreased.

  Here, when the number of transmissions decreases in the interval of the time width D, if the transmission data setting unit 373a sets the interval of the time width D as the transmission data, the number of transmissions is set large in the transmission data interval. A section that is reproduced after this section and has a relatively small number of transmissions is included. Therefore, after the section of the time width D is set first, only the section with a large number of transmissions is set as the section of transmission data to be transmitted thereafter, so that the transmission data sequentially transmitted by the code transmission means The order of sections may change. Therefore, when the number of transmissions decreases in the interval of time width D, the transmission data setting unit 373a sets the interval before the decrease in the number of transmissions as transmission data. However, even when the number of transmissions decreases in the interval of time width D, the transmission number setting means 372 sets a large number of transmissions by setting a transmission data section including a period before the number of transmissions decreases. When transmission data is set for the number of transmissions for the selected interval, the transmission data is transmitted even if it includes a playback time interval that is less in number of transmissions and slower than the interval for which the number of transmissions is set. The order of the transmission data sections is not changed. Therefore, even when the number of transmissions decreases in the section of the time width D, the transmission data setting unit 373a sets the transmission data section here, so that the number of transmissions is set by the transmission number setting means 372. When the transmission data is set for the number of times of transmission, the section of the time width D is set.

  Therefore, the transmission data setting unit 373a sets the transmission data section here, so that the transmission frequency setting section 373a sets the number of transmission times (for the period from the reproduction time 8d to 10d in which the transmission frequency setting means 372 sets a large number of transmission times ( It is determined whether transmission data is set only four times. Then, the transmission data setting unit 373a determines that even if the section from the reproduction time 7d to 10d is set as transmission data, the set number of transmissions is not reached for the section from the reproduction time 8d to 10d. A section j3 from 7d to 10d is set as a section of transmission data.

  Similarly, when the reproduction time 8d is input from the code monitoring control unit 371 as the start time of transmission data to be transmitted next, the transmission data setting unit 373a selects the section j4 from the reproduction time 8d to 10d. Set as a section of transmission data. Then, the transmission data setting unit 373a determines that the number of transmissions set by the transmission number setting unit 372 has not been reached for the section from the reproduction time 8d to 9d, and further selects the section j5 from the reproduction time 8d to 10d. Set as a section of transmission data.

  In addition, when the reproduction time 9d is input from the code monitoring control unit 371 as the start time of transmission data to be transmitted next, the transmission data setting unit 373a sets the start time of the section of transmission data to be transmitted next. The playback time is set to 9d. Then, the transmission data setting unit 373a determines whether there is a change in the number of transmissions set by the transmission number setting unit 372 in the section from the reproduction time 9d to the time width 4d, that is, the section from the reproduction time 9d to 13d. To do. Here, since the number of transmissions is set to 4 in the section from the playback time 9d to 10d, and the number of transmissions is set to 2 in the section from the playback time 10d to 13d, the transmission data setting unit 373a transmits in this section. Judge that the number of times has decreased.

  Subsequently, the transmission data setting unit 373a sets a transmission data section here, so that the number of transmissions set for the section from the reproduction time 8d to 10d in which the number of transmissions is set by the transmission number setting means 372 is set. It is determined whether transmission data is set only (four times). Then, the transmission data setting unit 373a determines that the set number of transmissions is reached for the section from the reproduction time 8d to 10d by setting the section from the reproduction time 9d to 10d as the transmission data, and the reproduction time 9d. To 13d is set as a transmission data section. As described above, the transmission data setting unit 373a can set the transmission data interval for the interval from the reproduction time 3d to 13d.

  When no transmission control information is input, the transmission data setting unit 373a sets a section obtained by dividing the encoded content for each unit data amount as a transmission data section.

  Here, the transmission data setting unit 373a can set the transmission data section so that the data corresponding to the section in which the high importance is specified in the transmission control information is transmitted more times. Therefore, the content receiving device 7 that receives and reproduces the content can receive data corresponding to a section having a higher importance with a higher probability, and has a higher importance than the entire content. In order to increase the number of transmissions for data corresponding to some sections, it is not necessary to repeatedly transmit old data or relatively unimportant data like the carousel transmission method, while efficiently transmitting, It is possible to improve resistance to a transmission path failure.

  Here, the unit data amount is specified by the time width when the content is reproduced, and the unit data amount set in advance based on the ratio between the bit rate and the transmission path band is set. The amount may be specified by, for example, the number of frames. The unit data amount may be set so that the transmission data amount per time does not exceed the transmission path band based on the bit rate of the encoded content. For example, the unit data amount corresponds to the bit rate value, etc. A predetermined unit data amount may be set.

  Returning to FIG. 2, the description will be continued. The transmission timing setting unit 373b receives the transmission data set by the transmission data setting unit 373a based on the data amount of each encoded content stored in the encoded content storage unit 40 and input from the code monitoring control unit 371. The transmission timing is set. Information on the transmission timing and transmission data section set here is output to the network monitoring means 374.

  Here, the transmission timing setting unit 373b uses the time when the set transmission data is stored in the encoded content storage unit 40 as the transmission timing for transmitting the transmission data, and the network monitoring unit 374 provides an instruction to transmit the transmission data. To output. That is, in the transmission timing setting unit 373b, the data amount of the encoded content stored in the encoded content storage unit 40 input from the code monitoring control unit 371 has reached the data amount of the set transmission data section. Sometimes, a command to transmit the transmission data is output to the network monitoring unit 374.

  Here, referring to FIG. 5 (refer to FIG. 2 as appropriate), the transmission data for each encoded content set by the transmission data setting unit 373a corresponds to a section on the time axis of the reproduction time of the content. An example in which the transmission timing setting unit 373b sets the transmission timing of transmission data to be transmitted will be described. FIG. 5A is an explanatory diagram schematically showing the transmission data section and transmission timing of the low bit rate encoded content set by the transmission setting unit 373, and FIG. 5B is a transmission setting unit. 4 is an explanatory diagram schematically showing transmission data intervals and transmission timing of medium bit rate encoded content set by 373. FIG. FIG. 5C is an explanatory diagram schematically showing the transmission data section and transmission timing of the high bit rate encoded content set by the transmission setting unit 373, and FIG. It is a time chart of the code transmission amount when the code transmission means 38 to transmit each encoded content at the transmission timing shown in (a) to (c). In FIG. 5D, the horizontal axis indicates the reproduction time, and the vertical axis indicates the code transmission amount.

  In FIG. 5, a section of transmission data transmitted at a time by the code transmission means 38 to be described later and a transmission timing for transmitting the transmission data are indicated by a reproduction time when the content is reproduced. For example, in FIG. 5A, the command M1 for transmitting the transmission data corresponding to the section m1 from the time when the reproduction of the content is started to the reproduction time 12d is 2d before the time when the reproduction of the content is started. It is shown that the data is output from the transmission setting means 373 during the reproduction time -2d shown.

  Here, it is assumed that the transmission data setting unit 373a specifies the unit data amount of each encoded content by the time width D based on the above formulas (1) to (3). Then, as shown in FIG. 5A, the transmission data setting unit 373a sets the unit data amount of the low bit rate encoded content as a time width D = 12d based on the equations (1) to (3). Assume that the section m1 of the reproduction time 0 to 12d is set as the section of transmission data to be transmitted first. Similarly, as shown in FIG. 5B, the transmission data setting unit 373a sets the sections m2 and m3 as the sections of transmission data to be transmitted first and next for the medium bit rate encoded content, As shown in FIG. 5 (c), for high bit rate encoded content, the sections m4, m5, m6, m7, m8, based on the retransmission section input from the transmission count setting means 372 and the number of transmissions thereof. Assume that m9 is set as a section of transmission data to be sequentially transmitted.

  The transmission timing setting unit 373b receives the data amount of each encoded content stored in the encoded content storage unit 40 from the code monitoring control unit 371 during the reproduction time -2d. Here, in the encoded content storage means 40, the interval m1 set in the transmission data setting unit 373a for the low bit rate encoded content, and the interval set in the transmission data setting unit 373a for the high bit rate encoded content. It is assumed that data corresponding to m4 is accumulated. Then, the transmission timing setting unit 373b transmits the data amount corresponding to the section m1 and the data amount corresponding to the section m4 from the code monitoring control unit 371 and the low bit rate encoded content stored in the encoded content storage unit 40 and the high amount. It is notified as the data amount of the bit rate encoded content. Based on this, the transmission timing setting unit 373b sets the reproduction time -2d as the transmission timing for transmitting the transmission data corresponding to the section m1 and the transmission data corresponding to the section m4. ), A command M1 for transmitting transmission data corresponding to the section m1 and a command M4 for transmitting transmission data corresponding to the section m4 are output at the reproduction time -2d.

  Similarly, as shown in FIGS. 5B and 5C, the transmission timing setting unit 373b transmits the transmission data of the medium bit rate encoded content corresponding to the section m2 in the reproduction time -d and the command M2 , A command M5 for transmitting transmission data of the high bit rate encoded content corresponding to the section m5 is output, and at the playback start time (playback time 0) of the content, the high bit rate encoded content corresponding to the section m6 is output. A command M6 for transmitting transmission data and a command M7 for transmitting transmission data corresponding to the section m7 are sequentially output during the reproduction time d. 5A to 5C, the lengths of the arrows of the commands M1, M2,... Indicate the amount of transmission data to be transmitted.

  Here, when the code transmission means 38 to be described later transmits the transmission data set by the transmission setting means 373 and shown in FIGS. 5A to 5C at each transmission timing, FIG. As shown in FIG. 5, the high bit rate encoded content is continuously transmitted for each data having a relatively short time width such as the sections m4, m5,. Further, the medium bit rate encoded content and the low bit rate encoded content are transmitted intermittently for each unit data amount having a relatively long time width.

  In this way, the transmission setting unit 373 causes the code transmission unit 38 to continuously transmit the encoded content with a high bit rate (the high bit rate encoded content in FIG. 5), and the encoded content with the low bit rate ( In FIG. 5, medium bit rate encoded content and low bit rate encoded content) are intermittently transmitted for each data having a large time width. For this reason, even when a failure occurs in the network 5 at a certain time and transmission data with a high bit rate transmitted from the code transmission means 38 at this time is not normally transmitted, it corresponds to the section at a different time. Since transmission data with a low bit rate including content data is transmitted, it is possible to prevent the content reproduction in the content receiving device 7 from being interrupted.

  Here, the transmission timing is the time when transmission data is stored in the encoded content storage means 40, but transmission is performed before the reproduction time of the transmission data when the content is reproduced by the content reception device 7 described later. For example, the transmission timing may be a time point a predetermined time before the reproduction time of the transmission data.

  Returning to FIG. 2, the description will be continued. The network monitoring unit 374 performs control to transmit transmission data when the network 5 is in a transmittable state based on the network information input from the network information input unit 36. Here, the network monitoring unit 374 monitors the occurrence and resolution of the failure of the network 5 based on the network information indicating the failure of the network 5, and transmits transmission data from the transmission timing setting unit 373b when the failure of the network 5 occurs. Is sent to the code transmission means 38 after the failure is resolved. The network monitoring unit 374 outputs the transmission instruction to the code transmission unit 38 as it is when a transmission instruction is input from the transmission timing setting unit 373b when the network 5 has not failed. The network information indicates, for example, information transmitted by the provider of the network 5 such as data transmission restriction performed when the network 5 is congested.

  Here, referring to FIG. 6 (refer to FIG. 2 as appropriate), the network monitoring means 374 transmits transmission data when the network 5 is in a transmittable state for encoded content of a certain bit rate based on the network information. An example of performing transmission control will be described. FIG. 6A is an explanatory diagram schematically showing an example of a section of transmission data set by the transmission setting unit 373, and FIG. 6B shows the transmission data of (a) by the transmission setting unit 373. FIG. 6C is an explanatory diagram schematically showing the timing of outputting a transmission command, and FIG. 6C shows a command for the network monitoring unit 374 that detects a failure of the network 5 from the network information to transmit the transmission data of the encoded content. It is explanatory drawing which showed typically the timing which outputs.

  Here, the sections k1, k2, k3, k4,... Shown in FIG. 6A are set as the transmission data sections by the transmission setting unit 373, and at the transmission timing shown in FIG. Assume that commands K1, K2, K3, K4,... for transmitting transmission data corresponding to k2, k3, k4,. In FIG. 6B, for example, the command (arrow in FIG. 6B) K1 is a part of the content that is reproduced from the reproduction time 3d to 7d by the content receiving device 7 that receives and reproduces the content. This is a command for transmitting a part of encoded content (data corresponding to the section k1) encoded as data as transmission data, and indicates that this command K1 is output from the transmission setting means 373 at the reproduction time 1d. ing.

  When the transmission timing setting unit 373b outputs a command as shown in FIG. 6B, the network monitoring unit 374 receives the command K1 at the reproduction time 1d. At this time, it is assumed that the network monitoring unit 374 has not detected a failure of the network 5. Therefore, as shown in FIG. 6C, the network monitoring unit 374 outputs this command K1 to the code transmission unit 38 during the reproduction time 1d.

  Next, as shown in FIG. 6B, the network monitoring unit 374 receives the command K3 from the transmission setting unit 373 at the reproduction time 2d. At this time, it is assumed that the network monitoring unit 374 detects the occurrence of a failure of the network 5 (schematically shown by hatching in FIG. 6C). Therefore, as shown in FIG. 6C, the network monitoring unit 374 does not output this command K2 during the reproduction time 2d.

  Then, as shown in FIG. 6B, the network monitoring unit 374 receives the command K3 from the transmission setting unit 373 at the reproduction time 3d. At this time, it is assumed that the network monitoring unit 374 detects the resolution of the network 5 failure. Therefore, the network monitoring unit 374 outputs the command K2 and the command K3 to the code transmission unit 38 at the reproduction time 3d as shown in FIG.

  Further, as shown in FIG. 6B, the network monitoring unit 374 receives a command K4 from the transmission setting unit 373 at the reproduction time 4d. At this time, it is assumed that the network monitoring unit 374 has not detected a failure of the network 5. Therefore, as shown in FIG. 6C, the network monitoring unit 374 outputs this command K4 to the code transmission unit 38 at the reproduction time 4d.

  As described above, when the network monitoring unit 374 detects a failure in the network 5, the transmission of the transmission data by the code transmission unit 38 is delayed and transmitted after the failure is resolved, so that the data is normal due to the failure in the network 5. When the data is not transmitted to the network, the transmission data is not transmitted, and the transmission data can be transmitted after it is normally transmitted. Therefore, the tolerance to the failure of the network 5 can be improved.

  Returning to FIG. 2, the description will be continued. The code transmission unit 38 sets the encoded content stored in the encoded content storage unit 40 for each unit data amount or by the transmission setting unit 373 based on a command to transmit transmission data input from the network monitoring unit 374. The data is transmitted for each transmitted data. Here, for each encoded content at each bit rate, the code transmission means 38 adds time information indicating a reproduction time when the content is reproduced to transmission data to be transmitted, and outputs the transmission data to the communication transmission / reception means 39. It shall be.

  The communication transmitter / receiver 39 transmits and receives data via the network 5. For example, the communication transmission / reception means 39 transmits / receives communication data using a TCP / IP (Transmission Control Protocol / Internet Protocol) communication protocol.

  The encoded content storage means 40 stores the encoded content that has been recognized or encoded by the speech recognition means 32, the medium bit rate encoding means 33, and the high bit rate encoding means 34. Storage means. The encoded content storage means 40 is, for example, a FIFO (First In First Out) type buffer memory.

The transmission setting information storage unit 41 stores parameters necessary for setting the transmission data section and transmission timing in the transmission setting unit 373, and is a general storage unit such as a ROM (Read Only Memory). It is. Here, the threshold values T ₁ , T ₂ , n ₁ , n ₂ , n ₃ used when the transmission data setting unit 373a sets the unit data amount based on the above formulas (1) to (3). And the transmission unit time d are stored in advance.

  By configuring the content transmission device 3 as described above, the content transmission device 3 encodes the content into encoded content of different bit rates, and recognizes the audio data as audio. The encoded content having a high bit rate is continuously transmitted for each data having a small time width, and the encoded content having a low bit rate is intermittently transmitted for each data having a large time width. Therefore, even when a failure occurs temporarily in the network 5 at a certain time and the transmission data transmitted at this time is not normally transmitted, the transmission data on the time axis of the content reproduction time Since transmission data of other bit rates including content data corresponding to the section are transmitted at different times, the content reception device 7 can receive encoded content of any bit rate.

  Furthermore, the encoded content with a high bit rate is likely to be affected by the failure of the network 5 because the amount of data is large, but the encoded content with a low bit rate is easy to transmit redundantly because the amount of data is small. Since it is easy to transmit long-term data all together, it is not easily affected by the failure of the network 5. Therefore, by transmitting the high bit rate encoded content generated from one content and the low bit rate encoded content, the content receiver 7 can encode at least a low bit rate even if the network 5 is in a bad state. Content can be received.

  Here, the content transmission apparatus 3 receives network information from the outside, and based on the network information, the network monitoring unit 374 determines whether the network 5 can be transmitted. Information may not be input, and for example, it may be determined whether the network 5 can be transmitted by a CSMA / CD (Carrier Sense Multiple Access / Collision Detection) method in Ethernet (R).

  The content transmission apparatus 3 can also realize each means as each function program in a computer, and can also function as a content transmission program by combining the function programs.

(Configuration of content receiving device)
Next, the configuration of the content receiving apparatus 7 will be described with reference to FIG. 7 (refer to FIG. 1 as appropriate). FIG. 7 is a block diagram showing the configuration of the content receiving device 7 in the present invention. The content receiving device 7 includes a receiving unit 71, a voice synthesizing unit 72, a medium bit rate decoding unit 73, a high bit rate decoding unit 74, a low bit rate decoded data reception state determination unit 75, and a medium bit rate decoded data. The determination means 76, the high bit rate decoded data determination means 77, the decoded data selection means 78, the decoded data output means 79, and the decoded data storage means 80 are provided.

  The receiving unit 71 receives encoded content via the network 5. For example, the receiving means 71 receives communication data using a TCP / IP communication protocol. The encoded content received here is output to the speech synthesizer 72, the medium bit rate decoder 73, and the high bit rate decoder 74.

  The voice synthesizer 72 receives the low bit rate encoded content (voice recognition data) transmitted from the content transmitter 3 via the receiver 71 and synthesizes the voice. The synthesized speech data synthesized here is stored in the decoded data storage means 80 as low bit rate decoded data.

  Here, in order to reduce the amount of information to be transmitted, the voice recognition data obtained by voice-recognizing the voice data of the content by the content transmission device 3 is voice-synthesized by the voice synthesizer 72 to obtain synthesized voice data. This solves the problem of losing features such as the speaker's way of speaking and voice, which has occurred in the conventional technique of outputting the contents of the text as text data. Note that the speech synthesizer 72 is described in, for example, “Invitation to Speech Synthesis Research—Toward Realization of Free Synthesis” (Hirose Hiroyoshi, IPSJ Magazine, Vol. 43, No. 3, Mar 2002). It can be realized using a general speech synthesis technique.

  The medium bit rate decoding means (decoding means) 73 receives and decodes the medium bit rate encoded content transmitted from the content transmitting apparatus 3 via the receiving means 71. The medium bit rate decoded data decoded here is stored in the decoded data storage means 80.

  The high bit rate decoding means (decoding means) 74 receives and decodes the high bit rate encoded content transmitted from the content transmitting apparatus 3 via the receiving means 71. The decoded high bit rate decoded data is stored in the decoded data storage unit 80.

  Note that here, the speech synthesis means 72, the medium bit rate decoding means 73, and the high bit rate decoding means 74 are divided into the respective decoded data (low bit rate decoded data, medium bit rate decoded data and high bit rate decoded data). It is assumed that the corresponding transmission data or time information added when transmitting through the network 5 is added and stored in the decoded data storage means 80.

  Here, the content receiving device 7 includes decoding means 73 and 74 for decoding encoded contents having different bit rates, and voice synthesizing means 72 for synthesizing voice recognition data of the contents. The content receiving apparatus 7 of the present invention may be configured to include at least two decoding units or at least one decoding unit and at least one speech synthesis unit in order to decode encoded contents having different bit rates.

  The low bit rate decoded data reception state determination means (synthetic speech data reception state determination means) 75 determines whether or not the low bit rate decoded data stored in the decoded data storage means 80 is missing. Here, the low bit rate decoded data reception state determining means 75 determines the deficiency by determining whether or not the low bit rate decoded data is accumulated in the decoded data storage means 80 for each section of a predetermined time width. The determination result of the defect determined here is output to the decoded data selection means 78.

  The medium bit rate decoded data determination means 76 determines the loss of the medium bit rate decoded data stored in the decoded data storage means 80, and the decoded data stored in the decoded data storage means 80 has been successfully decoded. It is what determines whether it is a thing. Here, the medium bit rate decoded data determination means 76 includes a reception state determination unit 76a and a decoding state determination unit 76b.

  The reception state determination unit (reception state determination unit, decoded data reception state determination unit) 76 a determines the loss of the medium bit rate decoded data stored in the decoded data storage unit 80. Here, the reception state determination unit 76a determines the deficiency by determining whether the medium bit rate decoded data is accumulated in the decoded data storage unit 80 for each section of a predetermined time width. The determination result of the defect determined here is output to the decoded data selection means 78.

  The decoding state determination unit (decoding state determination unit) 76b determines whether the medium bit rate decoded data stored in the decoded data storage unit 80 is normally decoded for each section of a predetermined time width. . The decoding determination result determined here is output to the decoded data selection means 78.

  The high bit rate decoded data determining means 77 determines the loss of the high bit rate decoded data stored in the decoded data storage means 80, and the decoded data stored in the decoded data storage means 80 has been normally decoded. It is what determines whether it is a thing. Here, the high bit rate decoded data determination unit 77 includes a reception state determination unit 77a and a decoding state determination unit 77b. The reception state determination unit 77a and the decoding state determination unit 77b have the same configuration as the reception state determination unit 76a and the decoding state determination unit 76b of the medium bit rate decoded data determination unit 76, and perform operations on the medium bit rate decoded content. The function is the same just by replacing it with the high bit rate decrypted content, and the description is omitted.

  Here, the low bit rate decoded data reception state determination unit 75, the reception state determination unit 76a of the medium bit rate decoded data determination unit 76, and the reception state determination unit 77a of the high bit rate decoded data determination unit 77 include the decoded data storage unit 80. Based on the time information indicating the reproduction time of the decoded data when the content is reproduced, the decoded data of a predetermined time width is stored in the decoded data storage unit 80. Can be determined. Note that the decoded data in the predetermined time interval determined here may be, for example, data for each frame, or used when setting the unit data amount of transmission data in the content transmission device 3. The data may be data for each time width of the transmission unit time d.

  In addition, the decoding state determination unit 76b of the medium bit rate decoded data determination unit 76 and the decoding state determination unit 77b of the high bit rate decoded data determination unit 77 are, for example, a general type such as CRC (Cyclic Redundancy Checking) or checksum. This can be determined by a decoding state determination method.

  The decoded data selection means 78 is based on the loss determination result and the decoding determination result input from the low bit rate decoded data reception state determination means 75, the medium bit rate decoded data determination means 76, and the high bit rate decoded data determination means 77. The decoded data having the highest bit rate is selected from the decoded data synthesized or decoded by the speech synthesis unit 72, the medium bit rate decoding unit 73, or the high bit rate decoding unit 74 for each interval of a predetermined time width. Then, a command to output the decoded data is output to the decoded data output means 79.

  Here, the decoded data selection means 78 determines whether the data is normally received and decoded normally for each section of a predetermined time width in order from the high bit rate decoded data. If the data is normally received and is normally decoded, the decoded data of the bit rate is selected. Here, the decoded data selection means 78 is the reception state determination section 77a of the high bit rate decoded data determination means 77, the reception state determination section 76a of the medium bit rate decoded data determination means 76, or the low bit rate decoded data reception state determination. With reference to the determination result of missing for each section of the predetermined time width of each decoded data determined by the means 75, it is determined whether it is normally received. In addition, the decoding state determining unit 77b of the high bit rate decoded data determining unit 77 or the decoding state determining unit 76b of the medium bit rate decoded data determining unit 76 for each section of the predetermined time width determined by the decoded data. With reference to the decryption determination result, it is determined whether the decryption is successful.

  The decoded data output means 79 reads the selected decoded data from the decoded data storage means 80 based on the command input from the decoded data selection means 78, and outputs it as reproduced content.

  The decoded data storage means 80 stores the decoded data that has been synthesized or decoded by the speech synthesis means 72, the medium bit rate decoding means 73, or the high bit rate decoding means 74, and is a general storage means such as a semiconductor memory. is there.

  By configuring the content receiving device 7 as described above, the content receiving device 7 receives encoded content having different bit rates encoded from the same content, or audio recognition data obtained by audio recognition of the audio data. Then, decoding or speech synthesis is performed, and data having the highest bit rate is output from the decoded or speech synthesized data. Further, the content receiving device 7 determines whether the decoded data is normally combined and outputs the decoded data having the highest bit rate among the decoded data that has been normally decoded. Even when decoding fails, it is possible to output decoded data of another bit rate that is normally decoded.

  Here, the low bit rate decoded data reception state determining unit 75, the reception state determining unit 76a of the medium bit rate decoded data determining unit 76, and the reception state determining unit 77a of the high bit rate decoded data determining unit 77 are stored in the decoded data storage. The loss is determined based on the time information added to the low bit rate decoded data stored in the means 80. For example, in the content transmission device 3, the transmission is performed by assigning a serial number to each transmission data. Then, the low bit rate decoded data reception state determining unit 75, the medium bit rate decoded data determining unit 76, and the high bit rate decoded data determining unit 77 of the content receiving device 7 determine the loss based on the serial number. Also good. Furthermore, by determining whether or not the encoded content corresponding to the decoded data in the section of the predetermined time width is transmitted based on the network information indicating the failure of the network 5 input from the outside via an input unit (not shown). It is good also as determining a defect | deletion.

  Further, the content receiving device 7 can also realize each means as a function program in a computer, and can also operate the contents reproduction program by combining the function programs.

[Operation of content transmission system]
Next, the operation of the content transmission system 1 according to the present invention will be described with reference to FIGS. Here, first, the operation of the content transmission device 3 will be described with reference to FIGS. 8 and 9. Next, the operation of the content receiving device 7 will be described with reference to FIG.

(Operation of content transmission device)
First, referring to FIG. 8 (refer to FIG. 1 and FIG. 2 as appropriate), the content transmitting apparatus 3 encodes the same content or recognizes audio data as a plurality of encoded contents with different bit rates. The operation of transmitting based on the transmission control information and the network information will be described. FIG. 8 is a flowchart showing an operation in which the content transmitting apparatus 3 according to the present invention transmits a plurality of encoded contents having different bit rates, in which the same contents are encoded or recognized.

  Here, the content input means 31 inputs the content, the voice recognition means 32 recognizes the voice data of the content, and the medium bit rate encoding means 33 and the high bit rate encoding means 34 encode the contents. The operation after encoding (encoding step) and storing the encoded content in the encoded content storage means 40 (encoded content storage step) will be described.

  In the content transmission device 3, the transmission data setting unit 373a of the transmission setting unit 373 sets a unit data amount of transmission data to be transmitted at a time for each encoded content of each bit rate based on the bit rate (step) S31). Here, the unit data amount of the unit is set by the time width D of the reproduction time of the transmission data when the content is reproduced.

  Then, the transmission count setting unit 372 determines whether new transmission control information is input via the transmission control information input unit 35 (step S32), and when no new transmission control information is input (step S32). If NO in S32, the process proceeds to step S34 as it is, and if new transmission control information is input (Yes in step S32), the transmission count setting means 372, based on the input transmission control information, A retransmission interval and the number of transmissions are set (step S33).

  Then, the transmission data setting unit 373a performs the code of each bit rate based on the unit data amount set in step S31, the retransmission interval and the number of transmissions set in step S33, by the transmission data interval setting operation described later. For each digitized content, a section of transmission data to be transmitted at a time is set (step S34).

  Then, the transmission timing setting unit 373b of the transmission setting unit 373 is set in step S34 based on the data amount of each encoded content stored in the encoded content storage unit 40, which is input from the code monitoring control unit 371. It is determined whether or not data having a data amount corresponding to the section is stored in the encoded content storage unit 40 (step S35). Then, when data of the data amount corresponding to the set section is not accumulated in the encoded content storage unit 40 (No in step S35), the encoding is input from the code monitoring control unit 371 after a predetermined time. Based on the data amount of each encoded content stored in the content storage unit 40, an operation is performed again to determine whether data of the data amount corresponding to the section is stored (step S35).

  In addition, when data of the data amount corresponding to the set section is accumulated in the encoded content storage unit 40 (Yes in step S35), the network monitoring unit 374 inputs via the network information input unit 36. Based on the network information, it is determined whether the network 5 can transmit, that is, whether a failure has occurred in the network 5 (step S36). If the network 5 is not ready for transmission (No in step S36), it is determined whether the network 5 can be transmitted again based on the network information input from the network information input means 36 after a predetermined time. Operation (step S36) is performed.

  When the network 5 is in a transmittable state (Yes in step S36), the network monitoring unit 374 outputs an instruction to transmit the transmission data corresponding to the section set in step S34 to the code transmission unit 38. Based on the command, the code transmission unit 38 reads out the transmission data from the encoded content storage unit 40 and transmits it via the communication transmission / reception unit 39 (step S37; code transmission step).

  Then, the code monitoring control unit 371 receives information on the section of the transmission data transmitted in step S37 from the network monitoring unit 374 and determines whether there is a section transmitted for the number of transmissions set in step S33 ( Step S38). If there is no section transmitted for the set number of transmissions (No in step S38), the process proceeds to step S40 as it is. If there is a section transmitted for the set number of transmissions (Yes in step S38), the code monitoring control unit 371 deletes data corresponding to this section from the encoded content storage unit 40 (step S39). ).

  Then, the code monitoring control unit 371 determines whether transmission of the set number of transmissions has been completed for all the encoded contents (step S40), and transmits the set number of transmissions for all of the encoded contents. If not (No in step S40), the process returns to step S32, and the operation after the operation in which the transmission number setting means 372 determines whether new transmission control information is input is performed. In addition, when all the encoded contents have been transmitted by the number of times of transmission (Yes in step S40), the operation ends.

  The transmission setting step described in the claims corresponds to the operation from step S31 to step S35.

  Through the above operation, the content transmission device 3 transmits transmission data at different timings for each of a plurality of encoded contents having different bit rates, in which the contents are encoded or recognized. Therefore, even when a failure occurs temporarily in the network 5 at a certain time, and the transmission data transmitted at this time is not transmitted normally, the content transmission device 3 does not transmit the section of the transmission data at a different time. In order to transmit transmission data of other bit rates including content data corresponding to, the content reception device 7 can receive encoded content of any bit rate. For this reason, there is no problem that data of all layers cannot be transmitted at the same time when the line is disconnected, which occurs in the conventional hierarchical coding transmission system.

  In addition, the content transmitting apparatus 3 can set a large number of data transmissions corresponding to a section designated with a high importance in the transmission control information, and can repeatedly transmit the data. Therefore, it is possible to cause the content receiving device 7 that receives and reproduces the content to receive data corresponding to a section having a higher importance with a higher probability. In addition, since the same data is transmitted at different times, it is not necessary to transmit the data separately using independent lines such as a satellite line, a dedicated line, and a public telephone line. As a result, the line cost can be kept low.

  Further, the content transmission device 3 delays transmission of transmission data when a failure of the network 5 is detected based on the network information, and improves the tolerance to the failure of the network 5 by transmitting after the failure is resolved. Can do.

(Transmission data section setting operation)
Next, referring to FIG. 9 (refer to FIG. 2 as appropriate), the content transmission device 3 uses the transmission data setting unit 373a of the transmission setting unit 373 to determine the retransmission interval and the number of transmissions of data corresponding to the interval. The operation (step S34 in FIG. 8) for setting the transmission data section of each encoded content stored in the encoded content storage means 40 will be described. FIG. 9 is a flowchart illustrating an operation in which the content transmission device 3 according to the present invention sets a transmission data section of encoded content.

  The content transmission apparatus 3 receives the transmission start time of the transmission data to be transmitted next on the time axis of the reproduction time of the content from the code monitoring control unit 371 by the transmission data setting unit 373a of the transmission setting unit 373 and transmits it. The start time of the data section is set (step S51). Then, the transmission data setting unit 373a determines whether there is a change in the number of transmissions set in step S33 in FIG. 8 in the section of the time width D set in step S31 in FIG. 8 from this start time ( Step S52). If there is no change in the number of transmissions in this section (No in step S52), the process proceeds directly to step S56. In addition, when there is a change in the number of transmissions in this section (Yes in step S52), the transmission data setting unit 373a decreases the number of transmissions as the playback time elapses in the section from the start time to the time width D. It is determined whether or not (step S53).

  If the number of transmissions has not decreased in this section (No in step S53), the process proceeds directly to step S56. When the number of transmissions decreases (Yes in step S53), the transmission data setting unit 373a sets the transmission data here, so that the set number of transmissions is reached for the section where the number of transmissions increases. Is determined (step S54). If the number of transmissions is reached (Yes in step S54), the process proceeds to step S56 as it is. If the number of transmissions has not been reached (No in step S54), the transmission data setting unit 373a uses, as transmission data, a section from the start time set in step S51 until the set number of transmissions decreases. Set (step S55), the process proceeds to step S57. In this way, by setting the section before the number of transmissions is reduced as transmission data, it is possible to prevent the order of the sections of transmission data transmitted in order by the code transmission means 38 from being changed.

  Further, when there is no change in the number of transmissions in the section from the start time to the time span D (No in step S52), there is a change in the number of transmissions in this section, but it is not decreasing (No in step S53), or Although the number of transmissions decreases, if the set number of transmissions is reached by setting the transmission data here (Yes in step S54), the transmission data setting unit 373a starts from the start time set in step S51. A section with a time width D is set as transmission data (step S56).

  Then, the transmission data setting unit 373a determines whether transmission data has been set by the number of transmissions set by the transmission number setting unit 372 in step S33 of FIG. 8 in the interval from the start time to the transmission unit time d. Judgment is made (step S57). If the transmission data is not set for the set number of transmissions (No in step S57), the transmission data setting unit 373a returns to step S52 and continues from the start time set in step S51. The operation after the operation of determining whether the number of transmissions set in step S33 in FIG.

  On the other hand, when transmission data is set for the set number of transmissions (Yes in step S57), the operation is terminated.

  Through the above operation, the transmission data setting unit 373a is stored in the encoded content storage unit 40 by the transmission data setting unit 373a of the transmission setting unit 373 based on the retransmission section and the number of times of transmission of data corresponding to the section. In addition, it is possible to set a time width D of each encoded content or a transmission data section having a time width shorter than the time width D. Then, the transmission data setting unit 373a can set the transmission data section so that the order of the transmission data sections transmitted in order by the code transmission means 38 is not changed.

(Operation of content receiver)
Next, referring to FIG. 10 (refer to FIG. 1 and FIG. 7 as appropriate), the content receiving apparatus 7 encodes the same content received via the network 5 or recognizes the audio data. An operation of reproducing the content from encoded content having different bit rates will be described. FIG. 10 shows an operation in which the content receiving apparatus 7 according to the present invention reproduces the content from a plurality of encoded contents with different bit rates, which are received through the network 5 and encoded or recognized by the same content. It is a flowchart.

  Here, the content receiving device 7 receives the encoded content via the receiving means 71 (receiving step), the speech synthesizing means 72 synthesizes the speech, and the medium bit rate decoding means 73 and the high bit rate decoding means 74 Each encoded content is decoded (decoding step) and stored in the decoded data storage unit 80 (decoded data storage step), and the reception state of the low bit rate decoded data reception state determination unit 75 and the medium bit rate decoded data determination unit 76 The determination unit 76a and the reception state determination unit 77a of the high bit rate decoded data determination unit 77 determine the reception state of each encoded content (reception state determination step), and the decoding state determination units 76b and 77b determine the decoding state. The subsequent operation will be described.

  The decoded data selection unit 78 of the content receiving device 7 refers to the determination result of the loss of the high bit rate decoded data in the section of the predetermined time width determined by the reception state determining unit 77a of the high bit rate decoded data determining unit 77. Then, it is determined whether or not the high bit rate decoded data corresponding to the section has been normally received (step S71).

  If it is determined that the high bit rate decoded data has not been received normally (No in step S71), the process directly proceeds to step S74. When it is determined that the high bit rate decoded data is normally received (Yes in step S71), the decoded data selecting unit 78 is determined by the decoding state determining unit 77b of the high bit rate decoded data determining unit 77. It is determined with reference to the determination result of the decoding state of the high bit rate decoded data corresponding to this section (step S72).

  If it is determined that the high bit rate decoded data has been normally decoded (Yes in step S72), the decoded data selection unit 78 determines that the decoded data having the highest bit rate has been normally received and decoded. Bit rate decoded data is selected (step S73), and the process proceeds to step S79. If it is determined that the high bit rate decoded data has not been decoded normally (No in step S72), the process proceeds to step S74.

  Subsequently, the decoded data selection unit 78 refers to the determination result of the lack of the intermediate bit rate decoded data corresponding to the predetermined time width determined by the reception state determination unit 76a of the intermediate bit rate decoded data determination unit 76. Then, it is determined whether the medium bit rate decoded data corresponding to the section has been normally received (step S74). If it is determined that the medium bit rate decoded data has not been received normally (No in step S74), the process directly proceeds to step S77. On the other hand, when it is determined that the medium bit rate decoded data has been received normally (Yes in step S74), the decoded data selecting means 78 is determined by the decoding state determining section 76b of the medium bit rate decoded data determining means 76. The decoding result of the medium bit rate decoded data corresponding to this section is referred to, and it is determined whether or not it has been normally decoded (step S75).

  If it is determined that the medium bit rate decoded data has been normally decoded (Yes in step S75), the decoded data selection unit 78 determines that the decoded data having the highest bit rate has been normally received and decoded. Bit rate decoded data is selected (step S76), and the process proceeds to step S79. If it is determined that the medium bit rate decoded data has not been decoded normally (No in step S75), the process proceeds to step S77.

  Subsequently, the decoded data selection unit 78 refers to the determination result of the loss of the low bit rate decoded data corresponding to the predetermined time interval determined by the low bit rate decoded data reception state determining unit 75, It is determined whether the low bit rate decoded data corresponding to the section has been normally received (step S77). If it is determined that the low bit rate decoded data has not been received normally (No in step S77), the process directly proceeds to step S80. When it is determined that the low bit rate decoded data is normally received (Yes in step S77), the decoded data selecting unit 78 sets the low bit rate decoded data as the highest bit rate decoded normally and decoded. Bit rate decoded data is selected (step S78), and the process proceeds to step S79.

  Then, the decoded data output means 79 outputs the decoded data corresponding to the section of the predetermined time width selected in step S73, S76 or S78 as the reproduced content (step S79; decoded data output step). Further, the decrypted data selection means 78 determines whether or not the output of the decrypted data has been completed for all sections of the content (step S80), and if not all sections have been completed (No in step S80). The decoded data selection means 78 sets the next section to be output by the decoded data output means 79 (step S81), returns to step S71, and the decoded data selection means 78 corresponds to the section set in step S81. The operation after the operation for determining whether or not the high bit rate decoded data has been normally received is performed. In addition, when all the sections are finished (Yes in step S80), the operation is finished.

  The decoded data selection step described in the claims corresponds to step S71 to step S78.

  Through the above operation, the content receiving device 7 can receive the low bit rate decoded data synthesized by the voice synthesizing unit 72 and the decoded data normally decoded by the medium bit rate decoding unit 73 or the high bit rate decoding unit 74. Of these, the decoded data with the highest bit rate can be output as playback content. Even when a failure occurs temporarily in the network 5 at a certain time and the transmission data transmitted from the content transmission device 3 cannot be received at this time, the content reception device 7 transmits the transmission at a different time. Since the transmission data of other bit rates including the data of the content corresponding to the data section is received, the content receiving device 7 can output the reproduced content without interruption.

[Contents transmission device usage example and unit data amount settings]
Next, with reference to FIG. 2, a usage example of the content transmission device 3 according to the present invention and setting of the unit data amount will be supplementarily described. Here, an example will be described in which 2-channel digital audio data subjected to 16-bit quantization with 48 kHz sampling is input as content, and an ADSL line having an effective transfer rate of about 1.2 Mbps is applied to the network 5.

  As the speech recognition means 32, a speech recognition device that outputs text data and phoneme information for faithfully reproducing speech as speech recognition data is applied. Text data is about 1000 bytes / minute if the speech rate is about 500 characters per minute, and the bit rate of low bit rate encoded content (speech recognition data) is about 1 kbps even if phoneme information is added.

  The medium bit rate encoding means 33 includes ITU-T (International Telecommunications Union-Telecommunications Standardization Sector). The G.729 encoding method is used. A 729 encoding device was applied. G. In the encoding by 729, since the audio data is band-limited to 8 kHz, high-frequency audio data does not exist, but human voices such as speech contents are appropriately encoded. Here, when the bit rate of the input audio data is 187 kbps, the bit rate of the medium bit rate encoded content is 8 kbps.

  The high bit rate encoding means 34 is an MPEG-2 AAC encoding apparatus that performs encoding using the MPEG-2 AAC (Moving Picture Experts Group 2 Advanced Audio Coding) method. Here, when the bit rate of the input audio data is 187 kbps, the bit rate of the high bit rate encoded content is 128 kbps.

Here, the transmission data setting unit 373a sets the unit data amount of the encoded content of the three types of bit rates stored in the encoded content storage unit 40 based on the formulas (1) to (3). A method will be described. The transmission setting information storage means 41 includes threshold values T ₁ = 1.0 × 10 ⁻³ , T ₂ = 10 × 10 ⁻³ , n ₁ = 2, n ₂ = 16, n ₃ = 128, and unit time. Assume that d = 10 ms is stored.

  When these encoded contents are transmitted by the code transmission means 38 using an ADSL line having an effective transfer rate of about 1.2 Mbps, the low bit rate encoded contents (speech recognition data) are expressed by Equation (1). Since it corresponds, the transmission data setting part 373a sets the time width D of the unit of the transmission data transmitted at once to 1280 ms. Similarly, since the medium bit rate encoded content (G.729 encoded content) corresponds to Equation (2), the transmission data setting unit 373a sets the time width D to 160 ms, and the high bit rate encoded content. Since (MPEG-2 AAC encoded content) corresponds to Equation (3), the transmission data setting unit 373a sets the time width D to 20 ms.

[Other usage examples of content transmission device and setting of unit data amount]
Furthermore, with reference to FIG. 11, another usage example of the content transmission apparatus according to the present invention and setting of the unit data amount will be supplementarily described. FIG. 11 is a block diagram showing the configuration of an example of use of the content transmission apparatus according to the present invention. As shown in FIG. 11, the content transmission device 3 </ b> A inputs content, encodes it into encoded content of three types of bit rates, and transmits it via the network 5. The content transmitting apparatus 3A does not include the voice recognition unit 32 in the content transmitting apparatus 3, but is configured by adding a low bit rate encoding unit 32A instead. In this example, moving image data of 720 × 480 pixels, 4: 2: 0 format, and 30 frames / second is input as content, and Ethernet (R) having an effective transfer rate of 80 Mbps is applied to the network 5. explain.

  For the low bit rate encoding means 32A, an encoding device that generates data necessary for CG synthesis on the receiving side as TVML is applied. The bit rate of the low bit rate encoded content is about 1 kbps, and data for generating CG that can reproduce the content of the moving image at an extremely low bit rate is generated.

  As the medium bit rate encoding means 33, an encoding device for encoding according to the MPEG-4 ASP (Advanced Simple Profile) system is applied. In MPEG-4 ASP encoding, the resolution was reduced to 352 × 288 and the frame rate was lowered to 15 fpt, and then encoded with MPEG-4 ASP, and the bit rate of the medium bit rate encoded content was set to 128 kbps.

  As the high bit rate encoding means 34, an encoding device for encoding according to the MPEG-2 Video system is applied. The bit rate of the high bit rate encoded content is about 8 Mbps, and sufficient quality can be obtained.

Here, a method in which the transmission setting unit 373 sets the unit data amount of the encoded content of three types of bit rates stored in the encoded content storage unit 40 will be described. The transmission setting information storage means 41 includes threshold values T ₁ = 1.0 × 10 ⁻³ , T ₂ = 10 × 10 ⁻³ , n ₁ = 2, n ₂ = 32, n ₃ = 4096, and unit time. Assume that d = 5 ms is stored.

  When these encoded contents are transmitted by the code transmission means 38 using Ethernet (R) having an effective transfer rate of 80 Mbps, the low bit rate encoded contents (TVML description) are expressed by the above equation (1). Since it corresponds, the transmission data setting part 373a sets the time width D of the unit of the transmission data transmitted at once to 20480 ms. Similarly, since the medium bit rate encoded content (MPEG-4 ASP encoded content) corresponds to the equation (2), the transmission data setting unit 373a sets the time width D to 160 ms and performs high bit rate encoding. Since the content (encoded content of MPEG-2 Video) corresponds to Equation (3), the transmission data setting unit 373a sets the time width D to 10 ms.

It is the block diagram which showed the structure of the content transmission system in this invention. It is the block diagram which showed the structure of the content transmission apparatus in this invention. It is explanatory drawing which showed the example of the transmission control information which shows a resending area and the importance of the data corresponding to the area. It is explanatory drawing which showed typically the example which a transmission data setting part sets the area of the transmission data of encoding content. (A) is an explanatory view schematically showing a transmission data section and transmission timing of low bit rate encoded content set by the transmission setting means, and (b) is set by the transmission setting means. Explanatory diagram schematically showing the transmission data section and transmission timing of medium bit rate encoded content, (c) is the transmission data section and transmission of high bit rate encoded content set by the transmission setting means Explanatory drawing schematically showing the timing, (d) is a time chart of the code transmission amount when the code transmitting means transmits each encoded content at the transmission timing shown in (a) to (c). . (A) is explanatory drawing which showed typically the example of the area of the transmission data set by the transmission setting means, (b) outputs the command which a transmission setting means transmits the transmission data of (a). Explanatory diagram schematically showing the timing, (c) is an explanation schematically showing the timing at which the network monitoring means that has detected a network failure from the network information outputs a command to transmit the transmission data of the encoded content FIG. It is the block diagram which showed the structure of the content receiver in this invention. It is the flowchart which showed the operation | movement which the content transmission apparatus in this invention transmits the encoding content of several different bit rate which encoded or recognized the same content. It is the flowchart which showed the operation | movement which the content transmission apparatus in this invention sets the area | region of the transmission data of an encoding content. It is the flowchart which showed the operation | movement which reproduces | regenerates the said content from the some encoded content of the different bit rate which the content receiver in this invention received via the network encoded or recognized the same content. It is the block diagram which showed the structure of the usage example of the content transmission apparatus in this invention.

Explanation of symbols

3 Content transmission device 32 Speech recognition means 33 Medium bit rate encoding means (encoding means)
34 High bit rate encoding means (encoding means)
372 Transmission count setting means 373 Transmission setting means 374 Network monitoring means 38 Code transmission means 40 Encoded content storage means (encoded content storage device)
7 content receiver 71 receiving means 72 speech synthesis means 73 medium bit rate decoding means (decoding means)
74 High bit rate decoding means (decoding means)
75 Low bit rate decoded data reception state determination means (synthesized speech data reception state determination means)
76a Reception state determination unit (reception state determination means, decoded data reception state determination means)
76b Decoding state determination unit (decoding state determination means)
77a Reception state determination unit (reception state determination means, decoded data reception state determination means)
77b Decoding state determination unit (decoding state determination means)
78 Decoded data selection means 79 Decoded data output means 80 Decoded data storage means (decoded data storage device)

Claims (11)

A content transmission device that encodes content and transmits the content via a network,
A plurality of encoding means for encoding the content into encoded content of different bit rates;
Encoded content storage means for storing the encoded content encoded by the encoding means;
For each encoded content stored in the encoded content storage means, based on the bit rate, a unit data amount as a unit of transmission data to be transmitted at a time, and the unit data amount transmitted for each unit data amount Transmission setting means for setting the transmission timing of transmission data;
A content transmission apparatus comprising: code transmission means for transmitting the transmission data at the transmission timing via the network. A part or all of the encoded content corresponding to the retransmission section is transmitted based on transmission control information designating a retransmission section of a part or all of the encoded content on the time axis of the playback time of the content. A transmission frequency setting means for setting the transmission frequency is provided.
The transmission setting means, for each encoded content, based on the bit rate, the retransmission interval, and the number of transmissions, a section on the time axis of transmission data transmitted by the code transmitting means, and Set the transmission timing and
The content transmission apparatus according to claim 1, wherein the code transmission unit transmits transmission data corresponding to a section set by the transmission setting unit at the transmission timing.   The network monitoring means for delaying the transmission timing at the time of occurrence of the network failure set by the transmission setting means based on network information indicating the failure of the network until after the failure is resolved. The content transmission apparatus according to claim 1 or 2. A content transmission device that encodes content and transmits the content via a network,
Encoding means for encoding the content into encoded content;
Speech recognition means for recognizing speech data included in the content as speech recognition data;
Encoded content storage means for storing the encoded content encoded by the encoding means and the speech recognition data recognized by the speech recognition means;
Based on the bit rates of the encoded content and the speech recognition data stored in the encoded content storage means, a unit data amount that is a unit of transmission data to be transmitted at a time, and for each unit data amount Transmission setting means for setting the transmission timing of transmission data to be transmitted;
A content transmission apparatus comprising: code transmission means for transmitting the transmission data at the transmission timing via the network. A content receiving device that receives encoded content obtained by encoding the same content at a plurality of bit rates from the content transmitting device according to any one of claims 1 to 3, and reproduces the content. ,
Receiving means for receiving transmission data constituting the encoded content;
Decoding means for decoding the transmission data received by the receiving means to obtain decoded data;
Decoded data storage means for storing the decoded data;
For each decoded data decoded by the decoding means, a reception state determining means for determining a loss of the decoded data constituting the content;
Based on the determination result of the loss determined by the reception state determination unit, decoded data selection unit that selects decoded data with the highest bit rate among the decoded data stored in the decoded data storage unit;
A content receiving apparatus comprising: decoded data output means for outputting the decoded data selected by the decoded data selection means. A decoding state determination unit that determines a decoding state of the decoded data decoded by the decoding unit;
The decoded data selection means selects the decoded data having the highest bit rate from among the decoded data stored in the decoded data storage means and determined to have been normally decoded by the decoding state determination means. The content receiving apparatus according to claim 5. A content receiving device for receiving encoded content obtained by encoding content and voice recognition data obtained by voice recognition of the audio data of the content from the content transmitting device according to claim 4, and reproducing the content. ,
Receiving means for receiving transmission data constituting the encoded content and the voice recognition data;
Decoding means that receives the reception means and decodes the transmission data constituting the encoded content to obtain decoded data;
Decrypted data reception state determining means for determining a loss of the decrypted data with respect to the content;
Speech synthesis means for synthesizing the transmission data received by the reception means and constituting the speech recognition data into synthesized speech data;
Synthetic voice data reception state determination means for determining a loss of the synthesized voice data with respect to the content;
Decoded data storage means for storing the decoded data and the synthesized speech data;
Based on the determination result of the loss determined by the decoded data reception state determination unit and the synthesized voice data reception state determination unit, of the decoded data and the synthesized voice data stored in the decoded data storage unit, Decoded data selection means for selecting high bit rate data;
A content receiving apparatus comprising: decrypted data output means for outputting data selected by the decrypted data selection means. A content transmission method in which content is encoded and transmitted via a network,
An encoding step of encoding the content into a plurality of different bit rate encoded content;
An encoded content storage step for storing the encoded content encoded in the encoding step in the encoded content storage device;
For each encoded content stored in the encoded content storage device, based on the bit rate, a unit data amount serving as a unit of transmission data to be transmitted at a time and a transmission transmitted for each unit data amount A transmission setting step for setting the data transmission timing;
And a code transmission step of transmitting the transmission data at the transmission timing via the network. A content reproduction method for receiving encoded content obtained by encoding the same content at a plurality of bit rates from the content transmission device according to any one of claims 1 to 3, and reproducing the content. ,
A reception step of receiving transmission data constituting the encoded content;
A decoding step of decoding the transmission data received in the reception step to obtain decoded data;
A decoded data storage step for storing the decoded data decoded in the decoding step in a decoded data storage device;
A reception state determination step for determining a loss of the decoded data constituting the content for each decoded data;
Based on the determination result of the loss determined in the reception state determination step, a decoded data selection step of selecting decoded data with the highest bit rate among the decoded data stored in the decoded data storage device;
A content reproduction method comprising: a decrypted data output step of outputting the decrypted data selected in the decrypted data selection step. To encode the content and send it over the network,
A plurality of encoding means for encoding the content into encoded content of different bit rates and storing the encoded content in an encoded content storage device;
For each encoded content stored in the encoded content storage means, based on the bit rate, a unit data amount as a unit of transmission data to be transmitted at a time and a transmission transmitted for each unit data amount Transmission setting means for setting data transmission timing,
A content transmission program that causes the transmission data to function as a code transmission unit that transmits the transmission data via the network at the transmission timing. A computer for receiving encoded content obtained by encoding the same content into a plurality of bit rates from the content transmission device according to any one of claims 1 to 3, and reproducing the content,
Receiving means for receiving transmission data constituting the encoded content;
Decoding means for decoding the transmission data received by the receiving means and storing it in the decoded data storage device;
A receiving state determining unit that determines, for each decoded data decoded by the decoding unit, a loss of the decoded data constituting the content;
Based on the determination result of the loss determined by the reception state determination means, decoded data selection means for selecting decoded data with the highest bit rate among the decoded data stored in the decoded data storage device,
A content reproduction program that functions as decrypted data output means for outputting decrypted data selected by the decrypted data selection means.

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