JP2014096672A - Content relay device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a content relay device capable of preventing decode interruption when a plurality of contents are decoded in parallel.SOLUTION: An AV receiver 1 stores a load table containing a plurality of formats and a plurality of assumed loads which are assumed when the content of each format is decoded. The AV receiver 1 predicts the total load to be applied in a case contents 2a and 5a are decoded, on the basis of the load table, when the start of decoding the content 5a from a radio server 5 is directed during decoding of the content 2a from a DLNA server 2. If the predicted total load exceeds a predetermined threshold value, the AV receiver 1 selects a content supplied from a server whose priority is lower on the basis of a priority table 33 in which the priority of each server is set. The format of the selected content is determined based on the load table so that the predicted total load becomes smaller than the threshold value.

Description

  The present invention relates to a content relay device, and more particularly to a content relay device that decodes content supplied from a server and supplies the decoded content to an external device.

  In a residence, a network AV system is used in which personal computers are mutually connected to AV (Audio and Visual) devices and these devices are operated in cooperation with each other. Such an AV network system complies with, for example, DLNA (Digital Living Network Alliance) guidelines.

  Patent Document 1 discloses a network AV system corresponding to the DLNA guidelines. The network AV system according to Patent Document 1 includes a server, a renderer, and a control point. The server decodes the song file and distributes it. The renderer plays the distributed music file. When receiving a request for a new streaming distribution, the control point predicts the load on the server when a new music file is decoded in addition to the decoding of the music file currently being distributed. When the predicted load on the server is large, the control point delegates the other server to decode and distribute the music file to be distributed.

  In Patent Document 1, a music file is decoded by a server. However, the server may stream the encoded music file and decode the streaming to which the renderer is distributed.

  In IP (Internet Protocol) simulcast, a server delivers encoded audio content in response to a request from a client such as a smartphone. The client decodes and reproduces the distributed audio content.

  Among content relay devices such as AV amplifiers, there are devices having a function of decoding content supplied from a server. When such a content relay device decodes a plurality of contents in parallel, the total load of the content relay device may increase. When the total load becomes excessively large, the content relay device temporarily interrupts decoding, which causes a problem that content supplied from the content relay device to the external device is interrupted.

JP 2008-71229 A

  An object of the present invention is to provide a content relay apparatus that can prevent interruption of decoding when a plurality of contents are decoded in parallel.

Means for Solving the Problems and Effects of the Invention

  The content relay device of the present invention includes a decoder, a first storage unit, a prediction unit, a determination unit, a second storage unit, a selection unit, and a determination unit. The decoder decodes the first and second contents supplied from the first and second servers, and supplies the decoded first and second contents to the external device. The first storage unit has a plurality of formats that can be decoded by the decoder, and a load that is a load of the decoder that is assumed when the decoder decodes the contents of each format and that has a plurality of assumed loads corresponding to the plurality of formats. Remember the table. When the prediction unit is instructed to start decoding the second content while the decoder is decoding the first content, the prediction unit displays the total load of the decoder when the first and second content are decoded in parallel. Predict based on The determination unit determines whether the total load predicted by the prediction unit exceeds a predetermined threshold value. The second storage unit stores a priority table in which priorities of the first and second servers are preset. When the determination unit determines that the predicted total load exceeds the threshold, the selection unit selects the content supplied from the server with the lower priority among the first and second content based on the priority table. select. The determination unit determines the format of the content selected by the selection unit based on the load table so that the predicted total load is smaller than the threshold value.

  According to the present invention, when the content relay apparatus decodes the first and second contents in parallel, the actual total load is prevented from greatly exceeding the threshold value. Therefore, the content relay device can prevent the decoding from being interrupted when the first and second contents are decoded in parallel.

  Preferably, the content relay apparatus of the present invention further includes a third storage unit. The third storage unit stores a format table in which a plurality of formats of content that can be supplied by a server with low priority are registered. The determining unit determines the format of the selected content in descending order of the assumed load of the decoder when the selected content is decoded based on the load table and the format table.

  According to the present invention, the format of the selected content is determined in descending order of the assumed load of the decoder among a plurality of formats that can be supplied by a server with low priority. When the content quality increases according to the assumed load, it is possible to prevent the quality of the selected content from being extremely lowered.

  Preferably, the selection unit determines that the predicted total load is larger than the threshold value even though the determination unit has determined the format with the smallest assumed load among the plurality of formats of the selected content. If it has been done, content supplied from the server with the next lowest priority is newly selected based on the priority table.

  According to the present invention, when a content is newly selected, the content relay apparatus selects content supplied from a server with the next lowest priority. Since the formats of the plurality of contents are determined so that the predicted total load falls below the threshold value, it is possible to further prevent the decoding from being interrupted.

  Preferably, a plurality of formats of content that can be supplied by the second server are registered in the format table. The prediction unit obtains the maximum load assumed when the decoder decodes the second content based on the load table and the format table, and sums the current load of the decoder and the acquired maximum load to obtain the total load. Predict.

  According to the present invention, the total load is predicted based on the current load on the decoder and the maximum load assumed when decoding the second content. Since the actual total load of the decoder in the case of decoding the first and second contents in parallel can be prevented from exceeding the predicted total load, it is possible to prevent the decoding from being interrupted.

  Preferably, when the information indicating that the selected content is provided via a broadcast wave is registered in the format table, the determination unit determines that the tuner can be used instead of the decoder.

  According to the present invention, when the selected content is provided via a broadcast wave, the tuner can demodulate the selected content. In this case, since the decoder does not have to decode the selected content, an increase in total load can be suppressed.

  Preferably, at least one of the first and second servers supplies Internet radio, and the other server supplies DLNA content. In the priority table, the priority of the server that supplies the Internet radio is set higher than the priority of the server that supplies the DLNA content.

  According to the present invention, the priority of the server that supplies the Internet radio is higher than the priority of the server that supplies the DLNA content. When the content quality increases according to the assumed load, it is possible to prevent the quality of the Internet radio from deteriorating.

  The control program of the present invention is used for the content relay apparatus of the present invention.

It is a functional block diagram which shows the structure of the network AV system which concerns on embodiment of this invention. It is a functional block diagram which shows the structure of the AV receiver shown in FIG. It is a figure which shows the data stored in the flash memory shown in FIG. It is a flowchart of the control program shown in FIG. It is a figure which shows the load table shown in FIG. It is a figure which shows the format table shown in FIG. It is a figure which shows the management table produced by the AV receiver shown in FIG. It is a flowchart of the format determination process shown in FIG. It is a figure which shows the priority table shown in FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

[1. Constitution]
[1.1. Configuration of network AV system]
FIG. 1 is a functional block diagram showing a configuration of a network AV system according to the present embodiment. Referring to FIG. 1, the network AV system includes an AV receiver 1, a DLNA server 2, a router 3, radio servers 4 and 5, and speakers 8a to 8d.

  The AV receiver 1, the DLNA server 2, and the router 3 are arranged in a house and constitute a LAN (Local Area Network) 7. The AV receiver 1 and the DLNA server 2 are connected to the router 3. Note that the number of DLNA servers 2 constituting the LAN 7 may be two or more.

  The AV receiver 1 decodes the audio content distributed from the DLNA server 2 and the radio servers 4 and 5, and supplies the decoded audio content to the speakers 8a to 8d. The speakers 8a to 8d are arranged in the rooms Zone1 to Zone4 of the residence. The DLNA server 2 is, for example, a personal computer, and distributes audio content 2a (DLNA content) in response to a request from the AV receiver 1.

  The router 3 is connected to the radio servers 4 and 5 via the Internet 6. Radio servers 4 and 5 are operated by radio stations A and B and provide Internet radio. Specifically, the radio servers 4 and 5 distribute audio contents 4a and 5a.

  In FIG. 1, the number of radio servers is two, but the number of radio servers may be one or three or more. Further, the server connected to the Internet 6 may not be a radio server that provides audio content, but may be any server that distributes content such as audio and video. Hereinafter, unless otherwise specified, the audio contents 2a, 4a, and 5a are referred to as “contents 2a, 4a, and 5a”.

[1.2. Configuration of AV receiver 1]
FIG. 2 is a functional block diagram showing the configuration of the AV receiver 1. FIG. 3 is a diagram showing data stored in the flash memory 16 shown in FIG.

  Referring to FIG. 2, an AV receiver 1 includes a CPU (Central Processing Unit) 11, a RAM (Random Access Memory) 12, an operation unit 13, a tuner 14, a network interface 15, a flash memory 16, and an output. Terminals 17a to 17d, a selector 18, and a D / A (Digital / Analog) converter 19 are provided.

  The CPU 11 loads various programs stored in the flash memory 16 into the RAM 12 and executes the loaded programs to control the AV receiver 1. The CPU 11 executes the decoding program 22 (see FIG. 3), decodes the contents supplied from the radio servers 4 and 5 and the DLNA server 2 and supplies the decoded contents to the outside. The RAM 12 is a main memory of the AV receiver 1.

  The operation unit 13 includes a volume adjustment dial and various buttons, and accepts user operations. The tuner 14 demodulates the broadcast received by an antenna (not shown).

  The network interface 15 communicates with a computer connected to the LAN 7 or the Internet 6 based on a protocol such as TCP / IP (Transmission Control Protocol / Internet Protocol).

  The output terminals 17a to 17d are connected to the speakers 8a to 8d, respectively. The output terminals 17a to 17d may be connected to an external device other than the speaker. For example, the output terminals 17a to 17d may be connected to a display for displaying video content.

  The D / A converter 19 converts the decoded content into an analog signal. The selector 18 controls the output destination of the decoded content. For example, when the output destination of the content 4a is set to the output terminals 17a and 17c, the D / A converter 19 is connected to the output terminals 17a and 17c.

  Referring to FIG. 3, flash memory 16 is a nonvolatile semiconductor storage device, and stores control program 21, decode program 22, load table 31, format table 32, and priority table 33.

  The control program 21 is a program for controlling each functional block of the AV receiver 1. The decode program 22 is a program for decoding content supplied from the DLNA server 2 or the like. The control program 21 and the decoding program 22 are installed in the AV receiver 1.

  The load table 31 has a plurality of formats that can be decoded by the decoding program 22 and a plurality of assumed loads. The plurality of assumed loads are loads of the CPU 11 assumed when the contents of each format are decoded, and correspond to the plurality of formats.

  The format table 32 is a table in which a plurality of formats of content that can be supplied by the DLNA server 2 and the radio servers 4 and 5 are set. The priority table 33 is a table in which priorities of the DLNA server 2 and the radio servers 4 and 5 are set in advance. Details of the load table 31, the format table 32, and the priority table 33 will be described later.

[2. Operation of AV receiver]
Hereinafter, the operation of the AV receiver 1 when the AV receiver 1 is instructed to decode new contents while decoding the contents supplied from the DLNA server 2 or the radio servers 4 and 5 will be described.

[2.1. Operation of control program 21]
FIG. 4 is a flowchart showing the operation of the AV receiver 1 that executes the control program 21. The CPU 11 loads the control program 21 into the RAM 12 and executes the loaded control program 21.

  Furthermore, it is assumed that the CPU 11 executes the decoding program 22 and decodes the content 2a from the DLNA server 2 and the content 4a from the radio server 4 in parallel. It is assumed that the decoded content 2a is supplied from the output terminal 17a to the speaker 8a, and the decoded content 4a is supplied from the output terminal 17b to the speaker 8b.

  The user operates the operation unit 13 to receive the Internet radio (content 5a) provided by the radio server 5, and instructs the AV receiver 1 to output the content 5a to the output terminal 17c. The CPU 11 determines that an instruction to start decoding the content 5a has been given (Yes in step S1), and determines whether the content 5a is currently being decoded (step S2).

  As described above, the contents 2a and 4a are decoded, but the contents 5a are not decoded (No in step S2). Therefore, the CPU 11 determines that it is necessary to newly decode the contents 5a. In addition to decoding the contents 2a and 4a, the CPU 11 predicts the total load on the CPU 11 when decoding of the contents 5a is started (step S3). Hereinafter, the total load predicted in step S3 is referred to as “predicted load”. Step S3 will be described later.

  On the other hand, if the content 5a is being decoded (Yes in step S2), the CPU 11 determines that there is no need to newly decode the content 5a, and ends the processing shown in FIG. For example, when the CPU 11 decodes the content 5a and outputs it to the output terminal 17d, the CPU 11 instructs the selector 18 to connect the D / A converter 19 to the output terminal 17c. The content 5a converted into an analog signal is supplied from the output terminals 17c and 17d to the speakers 8c and 8d.

  With reference to FIGS. 4 to 6, calculation of the predicted load (step S <b> 3) will be described. FIG. 5 is a diagram showing the load table 31. FIG. 6 is a diagram showing the format table 32.

  Since the CPU 11 is decoding the contents 2a and 4a, the CPU 11 acquires the current load of the CPU 11 as a load during decoding of the contents 2a and 4a. The CPU 11 refers to the format table 32 and acquires a plurality of formats of the content 5 a that can be supplied by the radio server 5. As shown in FIG. 6, the format of the content 5a that can be supplied by the radio server 5 is WMA (Windows Media Audio) with a bit rate of 128 kbps, AAC (Advanced Audio Coding) with a bit rate of 64 kbps, and FM broadcasting.

  Here, “FM broadcast” recorded in the format table 32 indicates that the content 5a is provided via a broadcast wave. When the AV receiver 1 receives the content 5a via a broadcast wave, the content 5a is demodulated by the tuner 14. In this case, since the CPU 11 does not process the demodulated content 5a, the load on the CPU 11 is 0% (see FIG. 5).

  The CPU 11 refers to the load table 31 and identifies the format with the largest assumed load among the three acquired formats. Referring to FIG. 5, in the load table 31, a plurality of formats of content that can be decoded by the decoding program 22 are associated with a plurality of assumed loads. The assumed load is a load that is predicted when the CPU 11 decodes the content of each format, and basically corresponds to the quality of the audio content. That is, the higher the load, the higher the quality of the audio content.

  The assumed loads of WMA (128 kbps), AAC (64 kbps), and FM broadcast, which are the formats of the content 5a, are 25%, 15%, and 0%, respectively. Of these three formats, the quality of WMA (128 kbps) is the highest and the quality of FM broadcast is the lowest. The CPU 11 acquires an assumed load (25%) of WMA (128 kbps) in consideration of the case where the content 5a of the highest quality format is decoded.

  In step S3, the CPU 11 calculates the predicted load by summing the current load of the CPU 11 and the acquired maximum assumed load.

  After step S3, the CPU 11 determines whether or not the predicted load calculated in step S3 is larger than a preset threshold value (step S4). The threshold value is the maximum value allowed as a load on the CPU 11 and is smaller than 100%.

  When the predicted load is equal to or less than the threshold value (No in step S4), the CPU 11 decodes the contents 2a and 4a and also decodes the content 5a in the maximum load format so that the decoding is temporarily interrupted. It is determined that the load of the will not increase. That is, the CPU 11 determines that the content is not interrupted even when the content 5a is newly decoded, and determines to decode the content 5a in the maximum load format (WMA (128 kbps)). The CPU 11 requests the radio server 5 to distribute the content 5a of WMA (128 kbps) (step S9), and ends the process shown in FIG. The formats of the contents 2a and 4a are not changed.

  On the other hand, when the predicted load is larger than the threshold value (Yes in step S4), the CPU 11 changes the format of the contents 2a and 4a or radios a format having a quality lower than the highest quality as the format of the contents 5a. It is determined that the server 5 needs to be requested. The CPU 11 creates the management table 40 in order to record the format of the contents 2a, 4a, 5a determined in step S6 described later (step S5).

  FIG. 7 is a diagram showing the management table 40. Referring to FIG. 7, the management table 40 has three columns 41, 42, and 43 corresponding to the contents 2a, 4a, and 5a, respectively. In each column, a content name, a server, a change reference format, a candidate format, and a final format are recorded.

  In the content name, information (for example, URL (Uniform Resource Locator)) specifying the content 2a, 4a, 5a is recorded. Information (server name, IP address, etc.) that identifies the server that supplies each audio content is recorded in the server. The change reference format and the candidate format are used in the format determination process (step S6). In the final format, the format of each content determined in the format determination process (step S6) is recorded. The change reference format, candidate format, and final format are blank when the management table 40 is created (step S5).

  CPU11 performs a format determination process (step S6) and determines the combination from which the prediction load is less than a threshold value among the combinations of each format of content 2a, 4a, 5a. Details of the format determination process (step S6) will be described later.

  After the format determination process (step S6), the CPU 11 determines whether there is a combination that causes the predicted load to fall below the threshold value based on the final format recorded in the management table 40 (step S7). .

  Referring to FIG. 7, when the final format of columns 41 to 43 is blank in management table 40, CPU 11 determines that there is no combination in which the predicted load falls below the threshold (No in step S7). . This indicates that the content 2a, 4a, 5a is likely to be interrupted by starting the decoding of the content 5a. The CPU 11 notifies the user that the content 5a cannot be reproduced (step S10), and ends the process shown in FIG. The notification in step S10 may be performed by voice, or a message may be displayed on a display panel (not shown) included in the AV receiver 1.

  On the other hand, if any format is recorded in the final format of the columns 41 to 43, the CPU 11 determines that there is a combination in which the predicted load is lower than the threshold (Yes in step S7). Based on the final format recorded in the management table 40, the CPU 11 requests content in the format of the content 2a, 4a, 5a (step S8). When the final format of the contents 2a and 4a is the same as the format currently being decoded, the CPU 11 does not need to request the DLNA server 2 and the radio server 4 to distribute the contents 2a and 4a in the final format.

[2.2. Format determination process (step S6)]
In the format determination process (step S6), the CPU 11 selects a server having a low priority from among the servers that distribute the contents 2a, 4a, and 5a, so that the quality of the content supplied from the selected server is lowered. Determine the format of this content. As a result, a combination in which the predicted load falls below the threshold value is determined.

[2.2.1. Content 2a format determination]
FIG. 8 is a flowchart of the format determination process (step S6). FIG. 9 is a diagram showing the priority table 33.

  Referring to FIG. 8, CPU 11 selects content supplied from the server with the lowest priority among servers recorded in management table 40 based on priority table 33 (step S601). As shown in FIG. 9, in the priority table 33, priorities of the radio server 4, the radio server 5, the radio station C (not shown), and the DLNA server 2 are set. The radio server 4 has the highest priority and the DLNA server 2 has the lowest priority. Since the DLNA server 2 has the lowest priority among the servers registered in the management table 40, the CPU 11 selects the content 2a in step S601.

  As described above, the priority of the DLNA server 2 is set lower than the priority of the radio servers 4 and 5, so that the quality of the Internet radio can be maintained.

  The CPU 11 determines the format of the selected content 2a in descending order of assumed load by executing steps S602 to S608. Since the CPU 11 is decoding the content 2a, the CPU 11 determines the current format of the content 2a as the change reference format (step S602). When the current format of the content 2 a is WMA (128 kbps), WMA (128 kbps) is registered in the column of change reference format in the column 41.

  With reference to the load table 31 and the format table 32, the CPU 11 determines a format with the largest assumed load after the change reference format among the formats of the content 2a that can be supplied by the DLNA server 2 as a candidate format (step S603). Referring to FIG. 6, the format of content 2a is PCM (Pulse Code Modulation), MP3 (MPEG Audio Layer-3) and WMA (128 kbps) with a bit rate of 128 kbps. The CPU 11 determines MP3 (128 kbps), which has the largest assumed load next to the change reference format (WMA (128 kbps)), as a candidate format, and registers MP3 (128 kbps) in the column of candidate format in the column 41.

  The CPU 11 calculates the degree of decrease in the predicted load when the format of the content 2a is changed to the candidate format (step S604). The degree of decrease is obtained by subtracting the assumed load of the candidate format from the assumed load of the change reference format. Referring to FIG. 5, the assumed load of the change standard format (WMA (128 kpbs)) is 25%, and the assumed load of the candidate format (MP3 (128 kpbs)) is 15%. It becomes. By changing the format of the content 2a to the candidate format, it is estimated that the prediction load is reduced by 10%.

  The CPU 11 updates the predicted load by subtracting the decrease degree from the predicted load calculated in step S3 (see FIG. 5) (step S605). The CPU 11 determines whether or not the updated predicted load is larger than a threshold value (step S606).

  If the updated predicted load is equal to or less than the threshold value (No in step S606), the CPU 11 changes the content 2a format from WMA (128 kbps) to MP3 (128 kbps), and parallelizes the contents 2a, 4a, and 5a. Even if the decoding is performed, it is determined that the possibility of interruption of each content is small. The CPU 11 determines the final format of the contents 2a, 4a, and 5a (step S612), and records the determined final format in the management table 40. Thereafter, the CPU 11 ends the format determination process (step S6).

  Specifically, the candidate format (MP3 (128 kbps)) of the content 2a is recorded in the column 41 as the final format. Since the content 4a is not selected in step S601, the current format (for example, WMA (128 kbps)) is recorded in the column 42 as the final format. The content 5a is a content that has been newly instructed to be decoded, and has not been selected in step S601. The final format of the content 5a is a format (WMA (128 kbps)) having the largest assumed load among a plurality of formats of the content that can be supplied by the radio server 5. As a result, the management table 40 has the contents shown in FIG. Since the contents 4a and 5a are not selected in step S601, the change reference format and the candidate format in the columns 42 and 43 remain blank.

  Referring to FIG. 4, CPU 11 requests DLNA server 2 and radio servers 4 and 5 to distribute the final format content recorded in management table 40 (step S8). As a result, the format of the content 2a is changed from WMA (128 kbps) to MP3 (128 kbps). The format of the content 4a remains WMA (128 kbps).

  Returning to the description of step S606 (see FIG. 8). When the updated predicted load is larger than the threshold value (Yes in step S606), the CPU 11 determines whether or not the quality of the content 2a can be further reduced. Specifically, it is determined whether or not the assumed load of the candidate format of the content 2a is the smallest among the assumed loads of a plurality of formats of content that can be supplied by the DLNA server 2 (step S607).

  5 and 6, in a plurality of formats that can be supplied by DLNA server 2, the assumed load of PCM is smaller than the assumed load of the candidate format (MP3 (128 kpbs)) (No in step S607). In this case, the CPU 11 determines that the quality of the content 2a can be further lowered, and changes the change reference format and the candidate format in the column 41 (step S608). In the column 41, the current candidate format (MP3 (128 kpbs)) is recorded as the change reference format, and the PCM with the largest assumed load after the current candidate format is recorded as the candidate format. The reason why the assumed load of PCM is set to 1% is that the content 2a is decoded by the DLNA server 2 and the AV receiver 1 does not need to decode.

  The CPU 11 calculates the degree of decrease when the candidate format is PCM based on the load table 31 and the management table 40 in which the column 41 is changed (step S604), and further updates the predicted load (step S605). If the updated predicted load is equal to or less than the threshold value (No in step S606), the final format of content 2a is determined to be PCM (step S612). The final format of the contents 4a and 5a is the same as described above.

  On the other hand, when the updated predicted load is larger than the threshold value (Yes in step S606), the CPU 11 determines that the assumed load of the candidate format (PCM) of the content 2a is the largest assumed load of the format of the content 2a. It is determined whether or not it is smaller (step S607). The assumed load of PCM is the smallest among the plurality of formats of the content 2a (Yes in step S607). The CPU 11 determines that the quality of the content 2a cannot be lowered any more, and proceeds to step S609.

  The CPU 11 refers to the priority table 33 and determines whether or not the DLNA server 2 that supplies the content 2a selected in step S601 has the highest priority (step S609). Referring to FIG. 9, since the priority of DLNA server 2 is the lowest (No in step S609), CPU 11 determines that the quality of the content supplied from the server with the next lowest priority can be lowered, Proceed to step S610.

  The CPU 11 determines the final format of the content 2a as the current candidate format (PCM) (step S610) and records it in the column 41. The CPU 11 continues the format determination process (step S6).

  As described above, the CPU 11 determines the format of the content 2a in descending order of the assumed load among the plurality of formats of the content 2a. This can prevent the quality of the content 2a from becoming extremely low. Since the content 2a is being decoded, the sound quality of the content 2a flowing from the speaker 8a can be prevented from being extremely lowered from the middle.

[2.2.2. Content 5a format determination]
Next, the CPU 11 refers to the priority table 33 and selects the content 5a supplied from the radio server 5 having the second lowest priority after the DLNA server 2 (step S611). The CPU 11 executes steps S602 to S608 in order to determine the final format of the content 5a.

  The content 5a is content that has been newly instructed to be decoded as described above. The change reference format of the content 5a is determined to be WMA (128 kbps) having the largest assumed load among a plurality of formats of content that can be supplied by the radio server 5 (step S602). The candidate format of the content 5a is determined to be AAC (64 kbps) having the largest assumed load next to WMA (128 kbps) (step S603). The CPU 11 executes steps S604 and S605, and determines whether or not the updated predicted load is a threshold value (step S606).

  When the updated predicted load is equal to or less than the threshold value (No in step S606), the CPU 11 determines the final format of the contents 4a and 5a (step S612). Specifically, the candidate format (AAC (64 kbps)) of the content 5a is recorded in the column 43 as the final format. The current format of the content 4a is recorded in the column 42 as the final format.

  When the updated predicted load is larger than the threshold (Yes in step S606), the CPU 11 determines whether the assumed load of the candidate format of the content 5a is the smallest among the assumed loads of the plurality of formats of the content 5a. Is determined (step S607). If not the minimum (No in step S607), the CPU 11 proceeds to step S608.

  On the other hand, if it is the minimum (Yes in step S607), the CPU 11 determines that the quality of the content 5a cannot be lowered any more, and proceeds to step S609. The CPU 11 refers to the priority table 33 and determines that there is a radio server 4 having a higher priority than the radio server 5 that supplies the content 5a (No in step S609). The CPU 11 determines the final format of the content 5a as the FM broadcast with the smallest assumed load (step S610) and records it in the column 43. That is, when the FM broadcast is recorded as the format of the content 5a in the format table 32, the CPU 11 determines that the content 5a can be acquired using the tuner. The CPU 11 continues the format determination process (step S6).

  As described above, when the format of the content 2a is determined to be the format with the smallest assumed load, the AV receiver 1 assumes the format of the content 5a supplied from the radio server 5 having the second lowest priority after the DLNA server 2. Determine in ascending order. Since the formats of the plurality of contents are determined so that the predicted load falls below the threshold value, it is possible to further prevent the contents from being interrupted. Further, even if an instruction to start decoding of new content is given, it is possible to prevent refusal to start decoding of new content.

[2.2.3. Content 4a format determination]
Next, the CPU 11 refers to the priority table 33 and selects the content 4a supplied from the radio server 4 with the next lowest priority after the radio server 5 (step S6111). The change reference format and the candidate format of the content 4a are determined (steps S602 and S603). The CPU 11 calculates a decrease degree of the predicted load (step S604), calculates and updates the predicted load based on the decrease degree (step S605).

  When the updated predicted load falls below the threshold value (No in step S606), the CPU 11 determines the current candidate format as the final format of the content 4a (step 612), and records the final format in the column 43.

  If not below the threshold (Yes in step S606), the CPU 11 determines whether or not the assumed load of the candidate format is the minimum of the assumed loads of the plurality of formats of content that can be supplied by the radio server 4. (Step S607). If not the minimum (No in step S607), the CPU 11 proceeds to step S608.

  On the other hand, if it is the minimum (Yes in step S607), the CPU 11 determines whether or not the priority of the radio server 4 is the highest (step S609). Referring to FIG. 9, since the priority of radio server 4 is the highest (Yes in step S609), even if each format of contents 2a, 4a, 5a is determined to be the format with the least load, the prediction load is the threshold. Cannot fall below the value. The CPU 11 determines that the content is interrupted by starting the decoding of the content 5a, and determines that the content 5a cannot be decoded (step S612). The CPU 11 changes all the final formats of the columns 41 to 43 to blanks. As described above, when the final format of the columns 41 to 43 is blank (No in step S7, see FIG. 4), the CPU 11 notifies that the content 5a cannot be decoded (step S10).

  As described above, when the AV receiver 1 is instructed to start decoding the content 5a during decoding of the content 2a, 4a, the DLNA server 2 and the radio server 4, so that the predicted load falls below the threshold value. 5 determines the format of the content supplied from the server with the lower priority. Thereby, the AV receiver 1 can suppress the interruption of the contents 2a, 4a, and 5a when the contents 5a are newly decoded.

  When the AV receiver 1 is instructed to start decoding the content 5a, the AV receiver 1 calculates a predicted load based on the current load and the maximum load assumed when the content is decoded. As a result, it is possible to prevent the load when the content 5a is actually decoded from being extremely increased from the predicted load, and thus it is possible to further suppress the interruption of the content.

  In the above-described embodiment, the AV receiver 1 including the tuner 14 has been described as an example of the content relay apparatus, but the present invention is not limited to this. An AV amplifier that does not include the tuner 14 can also be used as the content relay device. That is, the content relay device may be a device that decodes a plurality of contents supplied from a plurality of servers and supplies the decoded content to an external device.

  In the above embodiment, the priority of the radio server is set to be higher than the priority of the DLNA server in the priority table (see FIG. 9), but the present invention is not limited to this. The priority of the DLNA server may be higher than the priority of the radio server. The priority table 33 may be set by the user or may be set in advance in the AV receiver 1. The AV receiver 1 may determine the priority of the server according to the number of accesses. That is, the priority table 33 only needs to be set with the priorities of a plurality of servers that supply content.

  In the above-described embodiment, when the AV receiver 1 is instructed to decode the content 5a, the example in which the predicted load is calculated based on the maximum assumed load among the plurality of assumed loads of the content 5a has been described (step S3). However, it is not limited to this. For example, the AV receiver 1 may predict the total load in step S3 by adding a preset fixed value to the current load. That is, the AV receiver 1 may calculate the total load of the CPU 11 when the content 5a is newly decoded in addition to the decoding of the content 2a and 4a in step S3 based on the current load of the CPU 11.

  In the above embodiment, the example in which the load table 31, the format table 32, and the priority table 33 are stored in the flash memory 16 has been described. However, the present invention is not limited to this. For example, each table may be stored in a separate storage device. That is, the storage destination of each table is not particularly limited.

  In the above embodiment, when the AV receiver 1 executes the format determination process (step S6), the AV receiver 1 selects content supplied from a server with low priority, and selects the format of the selected content in descending order of assumed load. Although the example to determine was demonstrated, it is not restricted to this. The AV receiver 1 may select a format having the smallest assumed load from among the selected content formats, and may determine whether the predicted load based on the smallest format is smaller than a threshold value. That is, the AV receiver 1 may determine the format of the selected content based on the load table 31 so that the predicted load is smaller than the threshold value.

  In the above embodiment, in the format determination process (step S6), when the format of the content 2a with the smallest assumed load is selected, but the predicted load is larger than the threshold value, the CPU 11 next sets the priority. Although the example which selects the content 5a supplied from the low radio server 5 was demonstrated, it is not restricted to this. In this case, the AV receiver 1 may determine that the content 5a cannot be decoded.

  In the above embodiment, the example in which the control program 21 is installed in the AV receiver 1 has been described. The method for installing the control program 21 is not particularly limited. For example, the control program 21 may be downloaded from a server connected to the network and installed in the AV receiver 1. Alternatively, when a computer-readable medium (for example, an optical disk, a USB (Universal Serial Bus) memory, a flexible disk, etc.) on which the control program 21 is recorded is distributed, the control program 21 is installed in the AV receiver 1 from the medium. May be.

  While the embodiments of the present invention have been described above, the above-described embodiments are merely examples for carrying out the present invention. Therefore, the present invention is not limited to the above-described embodiment, and can be implemented by appropriately modifying the above-described embodiment without departing from the spirit thereof.

1 AV receiver 2 DLNA server 3 Router 4, 5 Radio server 6 Internet 7 LAN
11 CPU
12 RAM
13 Operation Unit 14 Tuner 15 Network Interface 21 Control Program 22 Decode Program 31 Load Table 32 Format Table 33 Priority Table 40 Management Table

Claims (7)

A decoder that decodes the first and second contents supplied from the first and second servers and supplies the decoded first and second contents to an external device;
A load table having a plurality of formats decodable by the decoder and a plurality of assumed loads corresponding to the plurality of formats, which are loads of the decoder assumed when the decoder decodes contents of each format A first storage unit for storing;
When the decoder is instructed to start decoding the second content while the decoder is decoding the first content, the total load of the decoder when the first and second content are decoded in parallel is A predictor for predicting based on a load table;
A determination unit that determines whether the total load predicted by the prediction unit exceeds a predetermined threshold;
A second storage unit for storing a priority table in which priorities of the first and second servers are preset;
Content supplied from a server with low priority among the first and second content based on the priority table when the determination unit determines that the predicted total load exceeds the threshold value A selection section for selecting
A content relay device, comprising: a determination unit that determines a format of the content selected by the selection unit based on the load table so that the predicted total load is smaller than the threshold value. The content relay device according to claim 1, further comprising:
A third storage unit that stores a format table in which a plurality of formats of content that can be supplied by the low-priority server are registered;
The determination unit determines a format of the selected content in descending order of an assumed load of the decoder when the selected content is decoded based on the load table and the format table . The content relay device according to claim 2,
The selection unit determines that the predicted total load is greater than the threshold value even though the determination unit determines a format with the smallest assumed load among a plurality of formats of the selected content. A content relay device that newly selects content supplied from a server with the next lowest priority based on the priority table. The content relay device according to claim 2 or 3,
In the format table, a plurality of formats of content that can be supplied by the second server are registered,
The prediction unit obtains a maximum load assumed when the decoder decodes the second content based on the load table and the format table, and calculates the current load of the decoder and the acquired maximum load. A content relay device that adds up and predicts the total load. The content relay device according to any one of claims 2 to 4,
The determination unit determines that a tuner can be used instead of the decoder when information indicating that the selected content is provided via a broadcast wave is registered in the format table. Content relay device. The content relay device according to any one of claims 1 to 5,
At least one of the first and second servers supplies internet radio, the other server supplies DLNA content,
In the priority table, a content relay device in which a priority of a server that supplies the Internet radio is set higher than a priority of a server that supplies the DLNA content. Decoding the first and second contents supplied from the first and second servers and causing a computer mounted on a content relay apparatus including a decoder to supply the decoded first and second contents to an external apparatus Control program
When the decoder is instructed to start decoding the second content while the decoder is decoding the first content, the total load of the decoder when the first and second content are decoded in parallel is: Based on a load table having a plurality of formats decodable by the decoder and a plurality of assumed loads corresponding to the plurality of formats, which are loads of the decoder assumed when the decoder decodes contents of each format. Predicting and
Determining whether the predicted total load exceeds a predetermined threshold;
When it is determined that the predicted total load exceeds the threshold, the priority of the first and second servers is determined based on a preset priority table, and the first and second contents Selecting content supplied from a lower priority server;
And determining a format of the selected content based on the load table so that the predicted total load is smaller than the threshold.

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