JP5246181B2 - Network content playback control device, network content playback control method, and video display device - Google Patents

Description

  The present invention relates to a network content playback control device, a network content playback control method, and a video display device that shorten a video stop period that occurs when switching network content delivered from a content delivery server.

  In recent years, services for distributing content from a content distribution server to user terminals via an IP (Internet Protocol) network have become widespread, and download services and streaming services (video on demand) have been provided. For example, ActVila (registered trademark) is listed as a service for a digital broadcast receiving apparatus.

  The download service is a method of reproducing content after receiving all streaming data of the content from the content distribution server.

  On the other hand, the streaming service is an on-demand format in response to a user request, and the user terminal receives the content streaming data continuously transmitted from the content distribution server, and reproduces the content based on the received streaming data. It is a method to do. In addition, the user can request the content distribution server for special reproduction such as fast-forwarding, fast-rewinding, chapter skipping, and the like. In order to realize such special playback, the content distribution server prepares special playback content such as fast-forward and fast-reverse, in addition to the normal playback content, and distributes when the user requests special playback. The content to be played is switched from the normal playback content to the special playback content.

  In the conventional network content playback control method, for example, when content switching from normal playback content to special playback content occurs, acquisition of normal playback content from the content distribution server is stopped when a special playback request is generated from the user. To stop playback of the normal playback content. Next, when the special reproduction content is acquired from the content distribution server and a predetermined amount of storage is completed, the special reproduction content is reproduced.

  In other words, in the conventional network content playback control method, since the video is stopped from the time when playback of normal playback content is stopped until the time of playback of special playback content, the response to the user request is poor and it causes discomfort to the user. It was. Therefore, various methods for shortening the video stop period have been devised.

  For example, there is one that plays back the normal playback content stored in the buffer unit in accordance with the playback speed of the special playback content between the time when playback of the normal playback content is stopped and the time when playback of the special playback content starts. (Patent Document 1).

Japanese Unexamined Patent Publication No. 2009-066541 (first page, FIGS. 7 and 8)

  In Patent Document 1, in order to play back at a speed matching the playback speed of the special playback content, a plurality of pictures included in a plurality of GOPs (picture groups) constituting the normal playback content stored in the buffer unit are used. Only I pictures are played. For this reason, when the playback speed of special playback content is low, such as normal playback content, the number of pictures played back per unit time is very small, and the content cannot be displayed smoothly. is there. On the other hand, when the playback speed of the special playback content is high, the number of pictures played back per unit time increases, so that the content can be displayed smoothly to some extent. There is a problem that the playback content is read out in a short time, and the video is likely to stop.

  The invention according to the present application has been made to solve such a problem, and a period in which no content is displayed after the reproduction of the content being reproduced is stopped and the reproduction of another content is started. It is an object of the present invention to obtain a network content control reproduction control apparatus capable of reproducing the content so that the content is displayed smoothly.

Network content reproduction control apparatus according to the present invention, from the content distribution server for distributing a second content to be reproduced at a different speed than the first content and the predetermined speed to be reproduced at a predetermined speed, said first a acquires the content or the second content network content reproduction control apparatus for reproducing, selection information indicating whether you want the content of the first content and the second content is input A selection information input unit; a data acquisition unit for acquiring the first content or the second content from the content distribution server based on the selection information input in the selection information input; and the data acquisition unit Buffer in which the acquired first content or second content is written And when the selection information indicating that the second content is acquired from the selection information acquisition unit when the data acquisition unit is acquiring the first content, the data is written in the buffer unit. The first content is configured until the reading of the first content is completed and the amount of writing of the second content to the buffer unit exceeds a predetermined amount, whichever is earlier A buffer that reads all the pictures included in a plurality of picture groups and starts reading the second content from the buffer unit after a write amount of the second content to the buffer unit exceeds a predetermined amount The control unit and the first content read by the buffer control unit are reproduced at the predetermined speed, and the buffer control unit reads the first content. And a reproduction section for reproducing the at different speeds the second content.

Another network content reproduction control apparatus according to the present invention, from a content distribution server that distributes content to be reproduced at a predetermined speed, a network content reproduction control apparatus which obtains the content reproduction, the content Data acquisition for acquiring the content from the content distribution server based on the acquisition position information input unit to which acquisition position information indicating from which position the acquisition position is input is input and the acquisition position information input in the acquisition position information A buffer unit in which the content acquired by the data acquisition unit is written, and the content acquired from a position different from the position acquired when the data acquisition unit acquires the content. When the acquisition position information is input, the buffer unit at that time When reading of the acquired portion of the content that has been inserted is completed and when the amount of writing of the additional acquisition portion acquired from the different position to the buffer unit exceeds a predetermined amount, whichever is earlier Until then, all the pictures included in the plurality of picture groups constituting the acquired part are read, and after the amount of writing of the additional acquisition part to the buffer part exceeds the predetermined amount, the addition from the buffer part A buffer control unit that starts reading of the acquisition part; and a reproduction unit that reproduces the acquired part and the additional acquisition part read by the buffer control unit at the predetermined speed.

  According to the network content reproduction control apparatus according to the present invention, the period during which the first content is not displayed is shortened after the reproduction of the first content is stopped until the reproduction of the second content is started, And the network content control reproduction | regeneration control apparatus which can be reproduced | regenerated so that the said 1st content may be displayed smoothly can be obtained.

It is a block diagram which shows the structure of the video display apparatus concerning Embodiment 1 of this invention. It is a figure which shows the buffer structure of the network content reproduction | regeneration control apparatus which concerns on Embodiment 1 of this invention. It is a flowchart which shows the reproduction | regeneration control method at the time of the content reproduction start of the network content reproduction | regeneration control apparatus which concerns on Embodiment 1 of this invention. It is a figure which shows the buffer state at the time of the content reproduction start of the network content reproduction control apparatus which concerns on Embodiment 1 of this invention. It is a flowchart which shows the reproduction | regeneration control method at the time of the content switching of the network content reproduction | regeneration control apparatus which concerns on Embodiment 1 of this invention. It is a figure which shows the buffer state at the time of the content switching of the network content reproduction | regeneration control apparatus which concerns on Embodiment 1 of this invention. It is a block diagram which shows the structure of the video display apparatus concerning Embodiment 2 of this invention. It is a flowchart which shows the reproduction | regeneration control method at the time of the content switching of the network content reproduction | regeneration control apparatus which concerns on Embodiment 2 of this invention. It is a figure which shows the buffer state at the time of the content switching of the network content reproduction | regeneration control apparatus which concerns on Embodiment 2 of this invention. It is a block diagram which shows the structure of the video display apparatus concerning Embodiment 3 of this invention. It is a flowchart which shows the reproduction | regeneration control method at the time of the content switching of the network content reproduction | regeneration control apparatus which concerns on Embodiment 3 of this invention. It is a figure which shows the buffer state at the time of the content switching of the network content reproduction | regeneration control apparatus which concerns on Embodiment 3 of this invention.

10 Content distribution server 20, 20a, 20b Video display device 200, 200a, 200b Network content playback control device 30 Remote control 210, 210b Data acquisition unit 220, 220a, 220b Buffer control unit 221 Buffer unit 230 Playback unit 231 Demultiplexer unit 232 Video Decoder unit 233 Audio decoder unit 240 Display unit 250 Speaker unit 260, 260b Control unit 270 Key reception unit

Embodiment 1 FIG.
FIG. 1 is a block diagram showing a configuration of a video display apparatus according to Embodiment 1 of the present invention. The video display device 20 according to the first embodiment includes a network content playback control device 200 (content playback control device), a display unit 240, and a speaker unit 250. The network content reproduction control apparatus 200 includes a data acquisition unit 210, a buffer control unit 220, a reproduction unit 230, a control unit 260, and a key reception unit 270 (a selection information input unit and an acquisition position information input unit). ing.

  The data acquisition unit 210 is an interface with the content distribution server 10, and makes a content acquisition request to the content distribution server 10 according to control by the control unit 260, and multiplexes from the content distribution server 10 using the MPEG-2 system. The transport stream format data with time stamp is obtained.

  The buffer control unit 220 buffers the data acquired by the data acquisition unit 210 in the buffer unit 221 as a storage medium (stores it by writing). Further, the data buffered in the buffer unit 221 is read at an appropriate timing according to control by the control unit 260 and transferred to the reproduction unit 230. The appropriate timing is, for example, a timing at which video and audio output does not stagnate, and if the video and audio bit rates increase, the amount of data consumed by the playback unit 230 increases. The number of transfers increases. That is, the data transfer rate increases.

  As the buffer unit 221, dedicated hardware may be used, or a RAM (Random Access Memory) not shown in FIG. 1 included in the network content reproduction control apparatus 200 may be used.

  The playback unit 230 includes a demultiplexer unit 231, a video decoder unit 232, and an audio decoder unit 233.

  The demultiplexer unit 231 analyzes the data transferred from the buffer control unit 220, and extracts PSI (Program Specific Information) section packets, video packets, audio packets, and the like. The extracted video packet is output to the video decoder unit 232 as video stream data, and the extracted audio packet is output to the audio decoder unit 233 as audio stream data.

  The video decoder unit 232 decodes the input video stream data and outputs it to the display unit 240.

  The audio decoder unit 233 decodes the input audio stream data and outputs it to the speaker unit 250.

  When the user operates the remote controller 30 and the key code received by the key receiving unit 270 is input, the control unit 260 interprets the key code and controls the data acquisition unit 210, the buffer control unit 220, and the playback unit 230. The control unit 260 and the key receiving unit 270 function as a selection information output unit that outputs selection information indicating that the data acquisition unit 210 selects what content to acquire from the content distribution server 10 to the data acquisition unit 210. have.

  First, the buffer control method of the network content playback control apparatus according to the first embodiment of the present invention will be described.

  As a method of buffering data in the buffer unit 221, there is a method (ring buffer) in which the end and the top of the buffer unit 221 are logically connected and handled like a ring. In this method, when data writing or data reading is performed up to the end of the buffer unit 221, data writing or data reading is performed from the top of the buffer unit 221.

  2 (2-a) and 2 (2-b) are diagrams showing the configuration of the buffer unit 221. The buffer unit 221 has an area from the start address MinP to the end address MaxP, and the buffer control unit 220 uses the latest area in which the data acquired by the data acquisition unit 210 is written as the write address, and the latest transferred to the playback unit 230 Are stored as read addresses. In (2-a), the read address is indicated as RP1 and the write address is indicated as WP1, and in (2-b), the read address is indicated as RP2 and the write address is indicated as WP2.

  The write address and the read address are initially at the same position (MinP), the write address is updated by writing data, and the read address is updated by reading data (2-a). In the figure, each time-stamped transport stream format data divided into data blocks of a predetermined unit is numbered (for example, 1 to 7). In addition, data that has been transferred to the reproduction unit 230 is indicated by a double frame. For example, in (2-a), data blocks 1 and 2 have been transferred, and data blocks 3 to 7 have not been transferred.

  The write address cannot overtake the read address. When the write address catches up with the read address, the buffer control unit 220 does not write data. This state is a buffer full state.

  Also, the read address cannot overtake the write address. When the read address catches up with the write address, the buffer control unit 220 does not read data. This state is a buffer underflow state.

  When the write address or read address advances to MaxP, the write address or read address returns to MinP (2-b).

  Next, FIG. 3 shows a playback control method at the start of content playback of the network content playback control apparatus according to the first embodiment of the present invention, and FIG. 4 (4-a) and (4-b) are used as an example for buffer status. explain.

  When the user operates the remote controller 30 to request the start of content playback (step 100), the control unit 260 instructs the data acquisition unit 210 to start a transmission request for normal playback content to the content distribution server 10, and instructs In response to this, the data acquisition unit 210 starts acquiring the normal playback content from the content distribution server 10 (step 101).

  The buffer control unit 220 starts buffering the data acquired by the data acquisition unit 210 in the buffer unit 221 (step 102).

  When buffering is started, it is determined whether or not a predetermined amount of buffering has been completed in the buffer unit 221 (step 103). If not, the process returns to step 103 and the determination is continued. If completed, the control unit 260 instructs the buffer control unit 220 to start data transfer to the reproduction unit 230. The buffer state at this time is as shown in FIG. 4 (4-a), and it is determined that the predetermined amount has been reached when the write address has advanced to WP1.

  Upon receiving the data transfer start instruction, the buffer control unit 220 reads data from the head address of the buffer unit 221 and starts data transfer to the reproduction unit 230 (step 104). The buffer state at this time is as shown in FIG. 4 (4-b). When data transfer is started, the read address advances to RP2, and the write address advances to WP2.

  When data transfer is started, the control unit 260 instructs the playback unit 230 to start playback. Receiving the reproduction start instruction, the reproduction unit 230 starts extraction of the PSI section packet, video packet, audio packet, and the like by the demultiplexer unit 231, and outputs the extracted video packet to the video decoder unit 232 as video stream data. The video decoder unit 232 decodes the data and outputs it to the display unit 240. The extracted audio packet is output to the audio decoder unit 233 as audio stream data, decoded by the audio decoder unit 233, and output to the speaker unit 250 (step 105).

  Thereafter, the normal reproduction content is reproduced until the user requests the reproduction stop or the reproduction is completed up to the end of the content.

  Next, the playback control method at the time of content switching of the network content playback control apparatus according to the first embodiment of the present invention will be described with reference to FIG. 5, and the buffer status will be described with reference to FIGS. To do.

  When the user operates the remote controller 30 during playback of the normal playback content and requests special playback such as fast forward, fast reverse, and chapter feed (step 200), the control unit 260 makes the content distribution server 10 to the data acquisition unit 210. The data acquisition unit 210 that has received the instruction stops transmission of the normal reproduction content (step 201).

  When the acquisition of the normal playback content is stopped, the write completion position (address) of the normal playback content written in the buffer unit 221 is acquired (step 202). The buffer state at this time is as shown in FIG. 6 (6-a), and WP 1 is the writing completion position of the normal playback content.

  When the write completion position of the normal playback content is acquired, the special playback content acquisition process and the normal playback content playback continuation process operate in parallel.

  When the normal playback content playback continuation process is started after step 202 (step 203), it is determined whether or not the normal playback content data transfer has been completed up to the normal playback content write completion position acquired in step 202. (Step 204) If not completed, return to Step 204 and continue the determination. It should be noted that the playback continuation processing in step 203 is normally performed so that at least two pictures (preferably all pictures) are included among pictures included in a plurality of GOPs (picture groups) constituting the normal playback content. It is assumed that the playback content is read from the buffer control unit 220 and transferred to the playback unit 230 and played back at the normal playback speed in the playback unit 230. On the other hand, if the data transfer of the normal playback content has been completed up to the write completion position of the normal playback content acquired in step 202, the control unit 260 stops the data transfer to the playback unit 230 with respect to the buffer control unit 220 Instruct.

  Receiving the data transfer stop instruction, the buffer control unit 220 stops data transfer to the reproduction unit 230 (step 205).

  When the data transfer is stopped, the control unit 260 instructs the playback unit 230 to stop playback. Receiving the instruction to stop playback, the playback unit 230 stops the packet extraction process of the demultiplexer unit 231, stops the decoding process of the video decoder unit 232 and the decoding process of the audio decoder unit 233, and stops the normal playback content. (Step 206).

  When the acquisition process of the special reproduction content is started after step 202, the control unit 260 instructs the data acquisition unit 210 to start a transmission request for the special reproduction content to the content distribution server 10, and receives the received data. The acquisition unit 210 starts acquiring special playback content from the content distribution server 10 (step 207).

  The buffer control unit 220 starts buffering the data acquired by the data acquisition unit 210 in the buffer unit 221 (step 208). The buffering starts from the writing completion position of the normal playback content acquired in step 202.

  When buffering is started, it is determined whether or not a predetermined amount of buffering has been completed in the buffer unit 221 (step 209). If it has not been completed, the process returns to step 209 to continue the determination. If completed, it is determined whether or not the normal playback content is being played back (step 210). The buffer state at this time is as shown in FIG. 6 (6-b), and it is determined that the predetermined amount has been reached when the write address has advanced to WP 2. Further, since the reproduction of the normal reproduction content is continued, the read address advances to RP2. In the drawing, in order to distinguish the special reproduction content from the normal reproduction content, alphabets are added to the data of the special reproduction content (for example, A to C).

  If it is in the playback state in step 210, data transfer stop (step 211) equivalent to step 205 and playback stop (step 212) equivalent to step 206 are performed, and the normal playback content is stopped.

  When the normal playback content is stopped, the control unit 260 instructs the buffer control unit 220 to start data transfer to the playback unit 230.

  Receiving the data transfer start instruction, the buffer control unit 220 sets the read address of the buffer unit 221 to be transferred to the playback unit 230 to the buffering start position where buffering of the special playback content is started in step 208 (step 213). ). The buffer state at this time is as shown in FIG. 6 (6-c), and the read address is set to RP 3 that has started buffering of the special playback content.

  The buffer control unit 220 reads data from the read address set in step 213 and starts data transfer to the reproduction unit 230 (step 214). The buffer state at this time is as shown in FIG. 6 (6-d). When data transfer is started, the read address advances to RP 4 and the write address advances to WP 4.

  When data transfer is started, the control unit 260 instructs the playback unit 230 to start playback. Receiving the reproduction start instruction, the reproduction unit 230 starts extraction of the PSI section packet, video packet, audio packet, and the like by the demultiplexer unit 231, and outputs the extracted video packet to the video decoder unit 232 as video stream data. The video decoder unit 232 decodes the data and outputs it to the display unit 240. The extracted audio packet is output to the audio decoder unit 233 as audio stream data, decoded by the audio decoder unit 233, and output to the speaker unit 250 (step 215).

  Thereafter, the special reproduction content is in a reproduction state until the reproduction is requested by the user or the reproduction is completed up to the end of the content.

  The above is a description of content switching from normal playback content to special playback content, but the same applies to content switching from special playback content to normal playback content. That is, the content switching operation in the present embodiment can be applied to the operation of switching the first content reproduced at a predetermined speed to the second content reproduced at a speed different from the predetermined speed.

  In addition, content switching from normal playback content to normal playback content such that normal playback content is newly acquired from the position where the specified chapter is included and played with a predetermined amount of buffering as in the chapter skip operation is performed. Applicable to operation. In this case, the user inputs the acquired position information indicating from which position the content is acquired to the key receiving unit 270 as the acquired position information input unit using the remote controller 30, and the control is performed based on the acquired position information. The data acquisition unit 210 may be controlled so that the unit 260 acquires content from the position indicated by the acquisition position information.

  As described above, according to the present embodiment, when a user requests special playback such as fast-forward, fast-reverse, and chapter feed during playback of normal playback content and switches to special playback content, buffering of the special playback content is performed. By continuing playback of normal playback content that has already been buffered until it reaches a predetermined amount, the video stop period that occurs when switching content can be shortened, increasing the responsiveness to user requests and making the user feel uncomfortable Reduce.

Embodiment 2. FIG.
FIG. 7 is a block diagram showing the configuration of the video display apparatus according to Embodiment 2 of the present invention. The network content playback control device 200a of the video display device 20a according to the second embodiment is configured by adding a buffer unit 222 to the buffer control unit 220 of the network content playback control device 20 of the first embodiment. have. The buffer control unit 220 a switches the buffering destination of the data acquired by the data acquisition unit 210 to the buffer unit 221 or the buffer unit 222. Further, the data transfer source to the reproduction unit 230 is switched to the buffer unit 221 or the buffer unit 222.

  The playback control method at the start of content playback of the network content playback control apparatus according to the second embodiment of the present invention is the same as that of the first embodiment. At the start of the first content playback, the data acquisition unit 210 and the first buffer unit 221 is connected, and the first buffer unit 221 and the playback unit 230 are connected to perform content playback.

  Next, the playback control method at the time of content switching of the network content playback control apparatus according to the second embodiment of the present invention will be described with reference to FIG. 8, and the buffer status will be described with reference to FIGS. To do.

  When the user operates the remote controller 30 during playback of the normal playback content and requests special playback such as fast forward, fast reverse, and chapter feed (step 300), the control unit 260 makes the content distribution server 10 to the data acquisition unit 210. The data acquisition unit 210 that received the instruction to stop the transmission request for the normal reproduction content stops the acquisition of the normal reproduction content (step 301).

  When the acquisition of the normal playback content is stopped, the write completion position of the normal playback content written in the first buffer unit 221 is acquired (step 302). The buffer state at this time is as shown in FIG. 9 (9-a), and WP 1 and RP 1 are very close to each other and are close to the buffer full.

  When the write completion position of the normal playback content is acquired, the data acquisition unit 210 and the second buffer unit 222 are connected and the buffering destination is switched from the first buffer unit 221 to the second buffer unit 222 (step 303). .

  When the buffering destination is switched, the special playback content acquisition process and the normal playback content playback continuation process operate in parallel.

  When the normal playback content playback continuation processing is started after step 303 (step 304), it is determined whether or not the normal playback content data transfer has been completed up to the normal playback content write completion position acquired in step 302. (Step 305) If not completed, the process returns to Step 305 to continue the determination. It should be noted that the playback continuation process in step 303 normally includes at least two pictures (preferably all pictures) among pictures included in a plurality of GOPs (picture groups) constituting the normal playback content. It is assumed that the playback content is read from the buffer control unit 220a, transferred to the playback unit 230, and played back at the normal playback speed in the playback unit 230. On the other hand, when the data transfer of the normal playback content has been completed up to the write completion position of the normal playback content acquired in step 302, the control unit 260 stops the data transfer to the playback unit 230 with respect to the buffer control unit 220a. Instruct.

  Receiving the data transfer stop instruction, the buffer control unit 220a stops data transfer to the reproduction unit 230 (step 306).

  When the data transfer is stopped, the control unit 260 instructs the playback unit 230 to stop playback. Receiving the instruction to stop playback, the playback unit 230 stops the packet extraction process of the demultiplexer unit 231, stops the decoding process of the video decoder unit 232 and the decoding process of the audio decoder unit 233, and stops the normal playback content. (Step 307).

  When the special reproduction content acquisition process is started after step 303, the control unit 260 instructs the data acquisition unit 210 to start a special reproduction content transmission request to the content distribution server 10, and receives the received data. The acquisition unit 210 starts acquiring special reproduction content from the content distribution server 10 (step 308).

  The buffer control unit 220a starts buffering the data acquired by the data acquisition unit 210 in the second buffer unit 222 (step 309).

  When buffering is started, it is determined whether or not a predetermined amount of buffering has been completed in the second buffer unit 222 (step 310). If it has not been completed, the process returns to step 310 to continue the determination. If completed, it is determined whether or not the normal reproduction content is being reproduced (step 311). The buffer state at this time is as shown in FIG. 9 (9-b), and it is determined that the predetermined amount has been reached when the write address has advanced to WP 2 of the second buffer unit 222. Further, since the reproduction of the normal reproduction content is continued, the read address of the first buffer unit 221 advances to RP2.

  If the playback state is the step 311, the data transfer stop equivalent to the step 306 (step 312) and the playback stop equivalent to the step 307 (step 313) are performed, and the normal playback content is stopped.

  When the normal playback content is stopped, the second buffer unit 222 and the playback unit 230 are connected, and the data transfer source to the playback unit 230 is switched from the first buffer unit 221 to the second buffer unit 222 (steps). 314).

  When the data transfer source is switched, the control unit 260 instructs the buffer control unit 220a to start data transfer to the reproduction unit 230.

  Receiving the data transfer start instruction, the buffer control unit 220a reads data from the head address of the second buffer unit 222 and starts data transfer to the reproduction unit 230 (step 315). The buffer state at this time is as shown in FIG. 9 (9-c). When data transfer is started, the read address advances to RP3, and the write address advances to WP3.

  When data transfer is started, the control unit 260 instructs the playback unit 230 to start playback. Receiving the reproduction start instruction, the reproduction unit 230 starts extraction of the PSI section packet, video packet, audio packet, and the like by the demultiplexer unit 231, and outputs the extracted video packet to the video decoder unit 232 as video stream data. The video decoder unit 232 decodes the data and outputs it to the display unit 240. The extracted audio packet is output to the audio decoder unit 233 as audio stream data, decoded by the audio decoder unit 233, and output to the speaker unit 250 (step 316).

  Thereafter, the special reproduction content is in a reproduction state until the reproduction is requested by the user or the reproduction is completed up to the end of the content.

  The above is a description of content switching from normal playback content to special playback content, but the same applies to content switching from special playback content to normal playback content.

  In the buffer method in the conventional content playback apparatus, the data acquisition speed (line speed) from the content distribution server exceeds the data transfer speed from the buffer unit to the playback unit (the buffer accumulation amount is close to 100%). When content switching occurs, it is necessary to store special reproduction content after waiting for data to be transferred from the buffer unit to the reproduction unit and to be freed up in the buffer unit. For this reason, even when the line speed is good, it takes time until the special reproduction content is stored in a predetermined amount.

  However, as described above, the content playback control apparatus according to the present embodiment requests special playback such as fast-forward, fast-reverse, and chapter-feeding during playback of normal playback content, and changes the content playback control device to special playback content. When switching, the special reproduction content is stored in a buffer different from the buffer storing the normal reproduction content. This eliminates the need to wait for special playback content to be stored until the buffer has enough free space, and reduces the time required to store a predetermined amount of special playback content in the buffer. The video stop period can be shortened, and the responsiveness to the user request can be enhanced to reduce the discomfort felt by the user.

Embodiment 3 FIG.
FIG. 10 is a block diagram showing the configuration of the video display apparatus according to Embodiment 3 of the present invention. The network content reproduction control apparatus 200b of the video display apparatus 20b according to Embodiment 3 includes a data acquisition unit 210b, a buffer control unit 220b, and a control unit 260b. The data acquisition unit 210b calculates a data acquisition rate calculation unit that calculates the acquisition rate of data that the data acquisition unit 210 acquires from the content distribution server 10 to the data acquisition unit 210 of the network content reproduction control apparatus 200 according to Embodiment 1. Is added. Also, the buffer control unit 220b calculates the data transfer rate for calculating the data transfer rate of the data transferred from the buffer unit 221 to the playback unit 230 to the buffer control unit 220 of the network content playback control apparatus 200 according to Embodiment 1. The part is added. In addition, the control unit 260b notifies the control unit 260 of the network content playback control apparatus 200 according to Embodiment 1 the buffering completion prediction time until the buffering of the special playback content in the buffer unit 221 reaches a predetermined amount. A buffering completion prediction time calculation unit to be calculated and a buffering start position calculation unit to calculate the buffering start position of the special playback content to the buffer unit 221 are added.

  The playback control method at the start of content playback of the network content playback control apparatus according to the third embodiment of the present invention is the same as in the first embodiment.

  Next, the playback control method at the time of content switching of the network content playback control apparatus according to the third embodiment of the present invention will be described with reference to FIG. 11, and the buffer status will be described with reference to FIGS. To do.

  When the user operates the remote controller 30 during playback of normal playback content and requests special playback such as fast forward, fast reverse, chapter feed, etc. (step 400), the data acquisition speed calculation unit calculates the data to be acquired from the content distribution server 10. An acquisition speed is calculated (step 401). Specifically, the data acquisition speed calculation unit measures the time T1 until the data acquisition unit 210b can acquire the predetermined data size A from the content distribution server 10, and divides the predetermined data size A by the time T1 to obtain data. The acquisition speed X is calculated.

  When the data acquisition speed is calculated, the control unit 260b instructs the data acquisition unit 210b to stop the transmission request for the normal reproduction content to the content distribution server 10, and the data acquisition unit 210b that receives the instruction receives the instruction for the normal reproduction content. Acquisition is stopped (step 402).

  When the acquisition of the normal playback content is stopped, the write completion position of the normal playback content written in the buffer unit 221 is acquired (step 403). The buffer state at this time is as shown in FIG. 12 (12-a), and WP1 is the writing completion position of the normal playback content.

  When the write completion position of the normal playback content is acquired, the data transfer rate calculation unit calculates the data transfer rate of the data transferred from the buffer unit 221 to the playback unit 230 (step 404). Specifically, the data transfer rate calculation unit acquires the offset value B of the read address of the buffer unit 221 that has been moved by the buffer control unit 220b reading the normal playback content during the predetermined time T2, and the offset value The data transfer rate Y is calculated by dividing B by the predetermined time T2.

  When the data transfer rate is calculated, the buffering completion prediction time calculation unit calculates the buffering completion prediction time until buffering of the special playback content in the buffer unit 221 reaches a predetermined amount (step 405). Specifically, the buffering completion prediction time calculation unit acquires the data acquisition rate X calculated by the data acquisition rate calculation unit in step 401, and divides the predetermined amount of buffering by the data acquisition rate X acquired C. By doing so, the buffering completion predicted time Z is calculated.

  When the buffering completion predicted time Z is calculated, the buffering start position calculation unit calculates the buffering start position of the special playback content to the buffer unit 221 (step 406). Specifically, the buffering start position calculating unit first obtains the data transfer rate X calculated in step 404 and the buffering completion predicted time Z calculated by the buffering completion predicted time calculating unit, and the buffering completion predicted time The data size D transferred from the buffer unit 221 to the playback unit 230 during Z is calculated. The data size D is D = X × Z from the data transfer rate X calculated in step 404 and the buffering completion predicted time Z. Next, a read address of the buffer unit 221 is acquired, and a position moved by the data size D from the position of the read address is calculated as a buffering start position. The buffer state at this time is as shown in FIG. 12 (12-b), and WP2 moved to the read address RP2 by the data size (data blocks 4 to 6 in the figure) becomes the buffering start position. In other words, in step 406, the buffering start position calculation unit, based on the data transfer rate X, reads scheduled area in which the normal playback content read by the buffer control unit 220b during the predicted time Z is written (FIG. 12 ( The data blocks 4 to 6) in 12-b) are obtained, and the special reproduction content is written at a position where the special reproduction content is not written in the area that is not read by the buffer control unit 220b in the read scheduled area. Set the start position. In step 406, the write start position of the special playback content is set to the position moved by the data size D from the read address position of the normal playback content. However, the position is behind the moved position. May be the write start position of the special reproduction content.

  If the buffering start position calculated in step 406 exceeds the normal playback content writing completion position acquired in step 403, the buffering start position is set as the normal playback content writing completion position.

  When the buffering start position is calculated, the special reproduction content acquisition process and the normal reproduction content reproduction continuation process operate in parallel.

  After step 406, when the normal playback content playback continuation processing is started (step 407), it is determined whether the data transfer of the normal playback content has been completed up to the buffering start position acquired in step 406 (step 408). If not completed, the process returns to step 408 to continue the determination. Note that the playback continuation processing in step 407 is normally performed so that at least two pictures (preferably all pictures) are included among pictures included in a plurality of GOPs (picture groups) constituting the normal playback content. It is assumed that the playback content is read from the buffer control unit 220b, transferred to the playback unit 230, and played back at the normal playback speed in the playback unit 230. On the other hand, when the data transfer of the normal playback content has been completed up to the write completion position of the normal playback content acquired in step 407, the control unit 260b stops the data transfer to the playback unit 230 with respect to the buffer control unit 220b. Instruct.

  Upon receiving the data transfer stop instruction, the buffer control unit 220b stops data transfer to the playback unit 230 (step 409).

  When the data transfer is stopped, the control unit 260b instructs the playback unit 230 to stop playback. Receiving the instruction to stop playback, the playback unit 230 stops the packet extraction process of the demultiplexer unit 231, stops the decoding process of the video decoder unit 232 and the decoding process of the audio decoder unit 233, and stops the normal playback content. (Step 410).

  After the special reproduction content acquisition process is started after step 406, the control unit 260b instructs the data acquisition unit 210b to start a special reproduction content transmission request to the content distribution server 10, and receives the received data. The acquisition unit 210b starts acquiring special playback content from the content distribution server 10 (step 411).

  The buffer control unit 220b starts buffering the data acquired by the data acquisition unit 210b in the buffer unit 221 (step 412). Buffering starts from the buffering start position acquired in step 406.

  When buffering is started, it is determined whether or not a predetermined amount of buffering has been completed in the buffer unit 221 (step 413). If it has not been completed, the process returns to step 413 to continue the determination. If completed, it is determined whether or not the normal reproduction content is being reproduced (step 414). The buffer state at this time is as shown in FIG. 12 (12-c), and it is determined that the predetermined amount has been reached when the write address advances to WP3. Further, since the reproduction of the normal reproduction content is continued, the read address advances to RP3.

  If it is in the playback state in step 414, the data transfer stop (step 415) equivalent to step 409 and the playback stop (step 416) equivalent to step 410 are performed, and the normal playback content is stopped.

  When the normal playback content is stopped, the control unit 260b instructs the buffer control unit 220b to start data transfer to the playback unit 230.

  Upon receiving the data transfer start instruction, the buffer control unit 220b sets the read address of the buffer unit 221 to be transferred to the playback unit 230 to the buffering start position where buffering of the special playback content is started in step 412 (step 417). ). The buffer state at this time is as shown in FIG. 12 (12-d), and the read address is set to RP4 which has started buffering of the special reproduction content.

  The buffer control unit 220b reads data from the read address set in step 417 and starts data transfer to the reproduction unit 230 (step 418). The buffer state at this time is as shown in FIG. 12 (12-e). When data transfer is started, the read address advances to RP5, and the write address advances to WP5.

  When the data transfer is started, the control unit 260b instructs the playback unit 230 to start playback. Receiving the reproduction start instruction, the reproduction unit 230 starts extraction of the PSI section packet, video packet, audio packet, and the like by the demultiplexer unit 231, and outputs the extracted video packet to the video decoder unit 232 as video stream data. The video decoder unit 232 decodes the data and outputs it to the display unit 240. The extracted audio packet is output to the audio decoder unit 233 as audio stream data, decoded by the audio decoder unit 233, and output to the speaker unit 250 (step 419).

  Thereafter, the special reproduction content is in a reproduction state until the reproduction is requested by the user or the reproduction is completed up to the end of the content.

  The above is a description of content switching from normal playback content to special playback content, but the same applies to content switching from special playback content to normal playback content.

  As described above, according to the present embodiment, when a user requests special playback such as fast-forward, fast-reverse, and chapter feed during playback of normal playback content and switches to special playback content, buffering of the special playback content is performed. The special reproduction content is stored at a position where the data size necessary for reproducing the normal reproduction content until the predetermined amount is reached is moved from the data reading position. This eliminates the need to wait for special playback content to be stored until the buffer has enough free space, and reduces the time required to store a predetermined amount of special playback content in the buffer. The video stop period can be shortened, and the responsiveness to the user request can be enhanced to reduce the discomfort felt by the user.

  Note that the network content playback control apparatus according to the second and third embodiments is not applied only when switching to content having a different playback speed, as with the network content playback control apparatus according to the first embodiment. The present invention can also be applied to a case where the playback is switched from a different position in the same content as in the chapter skip operation.

Claims (11)

Special reproduction for performing at least fast-forward and fast-reverse, which is generated separately from the first content and the first content that are multiplexed in accordance with the MPEG method and distributed in response to a user request, and the first content In a network content reproduction control device that acquires and reproduces the first content or the second content from a content distribution server that distributes second content that is content for use ,
A selection information input unit to which selection information indicating which of the first content and the second content is to be acquired;
A data acquisition unit for acquiring the first content or the second content from the content distribution server based on the selection information input in the selection information input;
A buffer unit in which the first content or the second content acquired by the data acquisition unit is written;
When the selection information for acquiring the second content is input from the selection information input unit when the data acquisition unit is acquiring the first content, the first data written in the buffer unit A plurality of pieces constituting the first content until reading of one content is completed and when the amount of writing of the second content to the buffer unit exceeds a predetermined amount, whichever is earlier All the pictures included in the picture group GOP (Group of Picture) are read out, and after the amount of writing of the second content to the buffer unit exceeds a predetermined amount, the reading of the second content from the buffer unit A buffer control unit for starting
A network comprising: a reproduction unit that reproduces the first content read by the buffer control unit at a predetermined speed, and reproduces the second content read by the buffer control unit at a speed different from that of the first content. Content playback control device.   The network content reproduction according to claim 1, wherein the buffer unit includes a first buffer unit in which the first content is written and a second buffer unit in which the second content is written. Control device. An acquisition speed calculation unit that calculates an acquisition speed when the acquisition unit acquires the first content from the content distribution server;
A transfer rate calculation unit for calculating a transfer rate at which the first content read from the buffer unit is transferred to the reproduction unit;
A predicted write time calculation unit that calculates a predicted time until a predetermined amount of the second content is written to the buffer unit based on the acquisition speed;
When selection information indicating that the second content is acquired from the selection information input unit in a state where the data acquisition unit is acquiring the first content, the data acquisition unit receives the second content. Before acquiring the content, the buffer control unit obtains a scheduled read area in which the first content read by the buffer control unit is written during the predicted time based on the transfer speed, and the buffer control is included in the scheduled read area. 2. A writing start position calculation unit that sets a writing start position of the second content at a position where the second content is not written in an area that is not read by the unit. The network content reproduction control device described. An acquisition speed calculation unit that calculates an acquisition speed when the acquisition unit acquires the first content from the content distribution server;
A transfer rate calculation unit for calculating a transfer rate at which the first content read from the buffer unit is transferred to the reproduction unit;
A predicted write time calculation unit that calculates a predicted time until a predetermined amount of the second content is written to the buffer unit based on the acquisition speed;
Before the data acquisition unit acquires the second content, the transfer amount transferred from the buffer unit to the playback unit during the predicted time is calculated based on the transfer speed, and the buffer unit immediately before The position moved by the transfer amount from the read position at which the first content is read or the position after the position is calculated as the write start position of the second content in the buffer unit. The network content reproduction control apparatus according to claim 1, further comprising a write start position calculation unit. In a network content playback control apparatus for acquiring and playing back content from a content delivery server that delivers content that is multiplexed in MPEG format and played back at a predetermined speed,
An acquisition position information input unit to which acquisition position information indicating from which position the content is acquired;
A data acquisition unit for acquiring the content from the content distribution server based on the acquisition position information input in the acquisition position information;
A buffer unit in which the content acquired by the data acquisition unit is written;
When the acquisition position information indicating that the content is acquired from a position different from the position acquired when the data acquisition unit is acquiring the content is input to the buffer unit at that time. When reading of the acquired part of the content that has been completed and when the amount of additional acquisition part acquired from the different position to the buffer unit exceeds a predetermined amount, whichever comes first, After all the pictures included in a plurality of picture groups GOP (Group of Picture) constituting the acquired part are read and the amount of writing of the additional acquired part to the buffer part exceeds the predetermined amount, the buffer part A buffer control unit that starts reading the additional acquisition part from:
A network content reproduction control apparatus comprising: a reproduction unit that reproduces the acquired part and the additional acquisition part read by the buffer control unit at the predetermined speed.   6. The network content reproduction control apparatus according to claim 5, wherein the buffer unit includes a first buffer unit in which the acquired part is written and a second buffer unit in which the additional acquisition part is written. . An acquisition speed calculation unit that calculates an acquisition speed when the acquisition unit acquires the acquired part from the content distribution server;
A transfer rate calculation unit for calculating a transfer rate at which the acquired part read from the buffer unit is transferred to the reproduction unit;
Based on the acquisition speed, a predicted write time calculation unit that calculates a predicted time until a predetermined amount of the additional acquisition part is written in the buffer unit;
When the acquisition position information indicating that the additional acquisition part is acquired when the data acquisition unit is acquiring the acquired part, before the data acquisition unit starts acquiring the additional acquisition part In addition, a read scheduled area in which the acquired part read by the buffer control unit during the predicted time is written based on the transfer speed is obtained, and the buffer control unit does not read out of the read scheduled area The network content reproduction control device according to claim 5, further comprising: a write start position calculation unit that sets a write start position of the additional acquisition part at a position where the additional acquisition part is not written to the network. An acquisition speed calculation unit that calculates an acquisition speed when the acquisition unit acquires the acquired part from the content distribution server;
A transfer rate calculation unit for calculating a transfer rate at which the acquired part read from the buffer unit is transferred to the reproduction unit;
Based on the acquisition speed, a predicted write time calculation unit that calculates a predicted time until a predetermined amount of the additional acquisition part is written in the buffer unit;
Before the data acquisition unit starts acquiring the additional acquisition part, the transfer unit calculates the transfer amount transferred from the buffer unit to the playback unit during the predicted time based on the transfer rate. Write that calculates a position moved by the transfer amount from the read position from which the acquired part was read immediately before or a position after the position as the write start position of the additional acquisition part in the buffer unit The network content reproduction control apparatus according to claim 5, further comprising a start position calculation unit. The network content reproduction control device according to any one of claims 1 to 8,
A video display device comprising: a display unit that displays content to be played back by the playback control device. Special reproduction for performing at least fast-forward and fast-reverse, which is generated separately from the first content and the first content that are multiplexed in accordance with the MPEG method and distributed in response to a user request, and the first content In a network content reproduction control method for acquiring and reproducing the first content or the second content from a content distribution server that distributes second content that is content for use ,
A first reproduction step of acquiring the first content and writing it to a buffer unit, reading the written first content and reproducing it at the predetermined speed;
When change information for changing the content to be acquired from the first content to the second content is input, a process for acquiring the second content and writing it to the buffer unit is started and written to the buffer unit The first content is read until the read of the first content is completed and the amount of the second content written to the buffer unit exceeds a predetermined amount, whichever is earlier A second reproduction step of reading out all the pictures included in a plurality of picture groups GOP (Group of Picture) constituting the image from the buffer unit and reproducing them at a predetermined speed;
A third reproduction step of reading out the second content from the buffer unit and reproducing it at a speed different from that of the first content after an amount of writing of the second content to the buffer unit exceeds a predetermined amount; A network content reproduction control method comprising: In a network content playback control method for acquiring and playing back content from a content delivery server that delivers content that is multiplexed in MPEG format and played back at a predetermined speed,
A first reproduction step of acquiring the content and writing it in a buffer unit, reading the written content and reproducing it at the predetermined speed;
When change information for changing the position for acquiring the content is input, processing for acquiring the content from the position changed based on the change information and writing it to the buffer unit is started, and the change information is input When the reading of the content written to the buffer unit by the time is completed, or when the writing amount of the content that has started to be acquired from the changed position to the buffer unit exceeds a predetermined amount, whichever comes first Until this time, all the pictures included in a plurality of picture groups GOP (Group of Picture) constituting the content written in the buffer unit until the change information is input are read from the buffer unit and A second playback step of playing back at a predetermined speed;
After the writing amount of the content that has started acquisition from the changed position to the buffer unit exceeds a predetermined amount, the content that has started acquisition from the changed position is read from the buffer unit at the predetermined speed. A network content reproduction control method comprising: a third reproduction step for reproduction.

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