JP2008270939A - Motion image distribution system, and server device and client device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that a user is given much stress before since the frame rate of a motion image to be displayed is not high enough during special reproduction and it takes a time to start the special reproduction after a special reproduction instruction is sent. <P>SOLUTION: A server device 10, when receiving client request data indicative of the special reproduction instruction, determines resolution of encoded data to be output to a client device 20 by a resolution determination unit 102 according to a special reproduction speed included in the client request data, and distributes motion image data of many frames in encoded data held in an encoded data holding unit 101 as encoded data for special reproduction to the client device 20. The client device 20 can display a special reproduction image generated by decoding the motion image data of many frames from the encoded data distributed from the server device 10, so that continuity of contents can be recognized. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a moving image distribution system, a server device, and a client device, and more particularly to a moving image distribution system that distributes moving image data via a network, a server device, and a client device that performs streaming reproduction.

  First, the moving picture coding technique used in the present invention will be described. In the present invention, an encoding technique called hybrid encoding is used. The hybrid encoding technique basically uses four techniques: motion compensation, frequency conversion, quantization, and variable length encoding. Examples of hybrid coding techniques include MPEG (Moving Picture Experts Group) -2, MPEG-4, and H.264.

  The encoded signal generated by the hybrid encoding technique is obtained by encoding a moving image signal using an I picture obtained by completing the encoding with a moving image signal of one screen and inter-screen correlation. It consists of P picture and B picture obtained. Among these, the P picture and the B picture are pictures that need to be decoded using a reference picture, and therefore, the decoding process is generally slower than the I picture. However, since encoding is performed using inter-screen correlation, the amount of code generated when encoding is smaller than that of an I picture. In general, the code amount of a picture is I picture> P picture> B picture. In the above hybrid coding technique, moving pictures are compressed by combining the above three types of pictures.

  In addition, several pictures are grouped to form a unit called GOP (Group of Picture). This GOP contains at least one I picture and can be independently reproduced in GOP units. FIG. 8 shows an exemplary structure of a GOP. The GOP shown in FIG. 8 is composed of one I picture, four P pictures, and ten B pictures, and an I picture is arranged at the top. As shown in FIG. 8, one I picture included in the GOP is generally used, and the amount of code is reduced by making the remaining pictures P and B pictures.

  By the way, in the server device, a moving image file, which is an encoded signal sequence obtained by encoding a moving image signal using such a hybrid encoding technology, is distributed to the client device via the network. In a moving image distribution system that decodes and plays back a received moving image file, the client device can play back at an arbitrary speed. In this case, when special playback (fast forward / rewind) of the video file received by the client device is performed, as shown in FIG. 9, the decoding process is performed from each GOP synthesized in time series of the received video file. A method of realizing special reproduction by selecting a light I picture and reproducing the encoded data of the selected I picture is conventionally known (for example, see Patent Document 1).

  In addition, when a client device performs special reproduction, a method of decoding encoded data first and thinning out a decoded image obtained thereby according to a special reproduction speed is also known (for example, see Patent Document 2). ). In the special reproduction method described in Patent Document 2, as shown in FIG. 10, first, the encoded data is decoded and “0”, “1”, “2”, “3”, “4”,. When a decoded image of each picture is generated and then the special playback speed is doubled, “0”, “2”, “4”,... For example, a decimation operation for selecting an even-numbered picture is performed. Next, in step 2, the deciphered decoded image is encoded to generate encoded data for special reproduction. In FIG. 10, the decoded picture “0”, “2”, “4”,..., After decimation, for example, encodes even-numbered picture images as continuous images, and generates the encoded data shown in step 2. is doing. In the conventional distribution system described in Patent Document 2, special reproduction images are generated by re-encoding encoded data received.

JP 2006-74511 A JP 2005-12277 A

  However, the conventional moving image distribution systems described in Patent Documents 1 and 2 have the following problems. First, assuming that each GOP is configured as shown in FIG. 8, it is assumed that fast-forwarding is executed at twice the fast-forwarding speed. In the conventional moving image distribution system described in Patent Document 1, the encoded data to be transmitted is determined as shown below. First, the number of image data (number of pictures) per second is calculated. When the fast-forwarding speed is double, the number of image data (number of pictures) per second is 60 (= 30 fps × 2 s).

  Subsequently, the number of GOPs of the number of image data (number of pictures) per second is calculated. If one GOP is composed of 15 pictures, the number of GOPs per second is 4 (= 60 ÷ 15) GOP. Therefore, there are four I pictures in the number of 60 image data (number of pictures). Finally, the four I pictures are used as encoded data to be transmitted. Therefore, in the conventional distribution system described in Patent Document 1, the frame rate of the encoded data to be transmitted is 4 fps when performing fast-forward reproduction twice.

  Next, in Patent Document 2, encoded data to be transmitted is generated as shown below. First, since the fast-forward speed is twice, the encoded data to be transmitted is image data every other frame. Therefore, the encoded data is decoded to obtain every other piece of decoded image data. Subsequently, 30 pieces of the decoded image data acquired every other frame are collected to generate a picture group having a frame rate of 30 fps. Then, the generated picture group is encoded, and the encoded data is determined as transmission data.

  From the above, in the encoded data generation method for special reproduction by the conventional moving image distribution system described in Patent Document 1, the frame rate of the encoded data to be transmitted is considerably small, 4 fps, compared with 30 fps for normal reproduction. Therefore, there is a problem that the continuity of the displayed moving image is lost, resulting in an unnatural moving image.

  In addition, in the special reproduction encoded data generation method by the conventional moving image distribution system described in Patent Document 2, the frame rate of the encoded data to be transmitted is 30 fps, and the continuity of the moving image is guaranteed. In the case of a large image size, such as the size, the method of Patent Document 2 that always involves a process of decoding and re-encoding encoded data requires a lot of time for the decoding / encoding process, and provides real-time performance. There is a problem of lacking.

  As described above, conventionally, the frame rate of the moving image to be displayed is insufficient at the time of special playback, or it takes time until the special playback starts after the special playback command is issued, which gives a great stress to the user. There is a problem.

  The present invention has been made in view of the above points, and a moving image capable of performing special reproduction without losing the continuity and real-time characteristics of moving images lost during special reproduction and without causing stress to the user who operates the video. An object is to provide an image distribution system, a server device, and a client device.

In order to achieve the above object, the moving image distribution system of the present invention is a moving image distribution system that distributes moving image encoded data from a server device to a client device via a network.
Data generation means for generating client request data for transmitting a special reproduction command specifying a special reproduction speed input from the outside and resolution information indicating the resolution of a display device for displaying a moving image, and transmitting the client request data to the server device; Decoding means for decoding moving picture encoded data received from the server device to generate moving picture data; and a display rate of moving picture data output from the decoding means not exceeding a maximum display rate that can be displayed on the display device And control means for outputting the controlled moving image data to the display device,
Server device
Encoded data holding means that holds a plurality of moving image encoded data having different resolutions, receives client request data transmitted from a client device via a network, and displays a special reproduction speed and display indicated by the received client request data. According to the resolution of the apparatus, the moving image encoded data having the highest number of reproduced images per unit time at the special reproduction speed is determined from the encoded moving image data held in the encoded data holding means. The image processing apparatus includes: a resolution determining unit; and a transmission unit that reads out the encoded moving image data having the resolution determined by the resolution determining unit from the encoded data holding unit and transmits the encoded data to the client device.

  In this invention, the client device can display the specially reproduced image obtained by decoding a large number of continuously reproducible moving image data from the encoded moving image data distributed from the server device, thereby improving the continuity of the content. Can be recognized.

In order to achieve the above object, the moving image distribution system of the present invention is a moving image distribution system that distributes moving image encoded data from a server device to a client device via a network.
A special playback command specifying a special playback speed input from the outside, resolution information indicating the resolution of a display device for displaying a moving image, and how many pieces of encoded data of an arbitrary resolution can be decoded per unit time in the own device. Data generating means for generating client request data for transmitting the decoding capability information indicating the above and transmitting it to the server device, and decoding for decoding the moving image encoded data received from the server device to generate moving image data And a control means for controlling the display rate of the moving image data output from the decoding means to be equal to or lower than the maximum display rate that can be displayed on the display device, and outputting the controlled moving image data to the display device,
Server device
Encoded data holding means that holds a plurality of moving image encoded data having different resolutions, receives client request data transmitted from a client device via a network, and displays a special reproduction speed and display indicated by the received client request data. According to the resolution of the apparatus, the moving image encoded data having the highest number of reproduced images per unit time at the special reproduction speed is determined from the encoded moving image data held in the encoded data holding means. Based on the decoding capability information indicated by the received client request data, the resolution determination unit and the resolution determined by the resolution determination unit read from the encoded data holding unit have a resolution that can be decoded by the client device. Correction means for correcting, and encoded data whose resolution is corrected by the correction means to the client And a sending means for sending the location.

  According to the present invention, the resolution is corrected based on the decoding capability information of the client device, and a large number of the moving image encoded data after the correction is transmitted to the client device via the network as encoded data for special reproduction. Can be delivered.

  In order to achieve the above object, the present invention provides a server device that distributes moving image encoded data to a client device via a network, and holds encoded data that holds a plurality of moving image encoded data having different resolutions. Request for transmitting a means, a special reproduction command specifying the special reproduction speed input from the outside of the client device, and resolution information indicating the resolution of the display device for displaying a moving image generated in the client device The data is received via the network, and the special reproduction is selected from the moving image encoded data held in the encoded data holding means according to the special reproduction speed indicated by the received client request data and the resolution of the display device. Resolution that determines the resolution of moving image encoded data with the highest number of playback images per unit time at speed A constant section, characterized in that the video encoded data of the resolution determined by the resolution determination means reads from the coded data holding means and a transmitting means for transmitting to the client device.

  The server device according to the present invention can read out encoded data having a resolution for determining a resolution capable of recognizing image continuity at a special reproduction speed from the encoded data holding unit and transmit it to the client device.

  In order to achieve the above object, the present invention provides a server device that distributes moving image encoded data to a client device via a network, and holds encoded data that holds a plurality of moving image encoded data having different resolutions. Means, a special playback command specifying the special playback speed input from the outside of the client device, resolution information indicating the resolution of the display device for displaying the moving image, and any arbitrary Client request data for transmitting decoding capability information indicating how many resolution encoded data can be decoded per unit time is received via the network, and the special playback speed and display indicated by the received client request data The moving image held in the encoded data holding means according to the resolution of the device The resolution is determined by resolution determining means for determining moving image encoded data having the highest number of reproduced images per unit time at a special playback speed from the encoded data, and resolution determining means read from the encoded data holding means. Correction means for correcting the resolution moving image encoded data to a resolution that can be decoded by the client apparatus based on the decoding capability information indicated by the received client request data, and the encoded data whose resolution is corrected by the correction means as the client apparatus And transmitting means for transmitting to.

  The server device according to the present invention can correct to a resolution that can be decoded by the client device based on the decoding capability information indicated by the received client request data, and transmit the encoded data with the corrected resolution to the client device.

  In order to achieve the above object, the present invention distributes moving image encoded data generated by a server device via a network, and decodes the distributed moving image encoded data to generate moving image data. In the client device, client request data for transmitting a special reproduction command specifying the special reproduction speed input from the outside and resolution information indicating the resolution of the display device for displaying the moving image is generated and transmitted to the server device. Special reproduction determined from the moving image encoded data held in the server device according to the data generation means and the special reproduction speed indicated by the client request data received by the server device and the resolution of the display device Receives moving image encoded data having the highest number of reproduced images per unit time at the speed from the server device and receives it. Decoding the moving image encoded data to generate moving image data, and controlling the display rate of the moving image data output from the decoding unit to be equal to or lower than the maximum display rate that can be displayed on the display device, And control means for outputting the controlled moving image data to the display device.

  In order to achieve the above object, the client device of the present invention includes a special playback command specifying a special playback speed input from the outside, resolution information indicating the resolution of a display device for displaying a moving image, and the own device. Generating the client request data for transmitting the decoding capability information indicating how many pieces of encoded data of arbitrary resolution can be decoded per unit time, and the server device received the data In accordance with the special playback speed indicated by the client request data and the resolution of the display device, the number of playback images per unit time is determined at the special playback speed determined from the moving image encoded data held in the server device. The encoded video data with the highest resolution is corrected based on the decoding capability information indicated by the received client request data. The encoded video data of the resolution is received from the server device, the decoding means for decoding the received video encoded data to generate the video data, and the video data output from the decoding means Control means for controlling the display rate to be equal to or lower than the maximum display rate that can be displayed on the display device and outputting the controlled moving image data to the display device may be employed.

  According to the present invention, the server device that transmits the encoded data controls the resolution of the encoded data according to the special reproduction speed, and transmits the encoded data of the controlled resolution to the client device in real time. Since the encoded data is decoded and the image to be displayed is controlled according to the special playback speed, the continuity of the content can be recognized by the client device, and as a result, the continuity of the content, which has been a conventional problem, cannot be recognized. The problem can be solved, and special reproduction can be performed without giving stress to the user who operates the client device.

  Further, according to the present invention, the resolution is corrected based on the decoding capability information of the client device, and the server device encodes a large number of encoded data after the correction to the client device via the network. Since it is distributed as data, the client device can decode the encoded data distributed from the server device and display the special reproduction image in real time, and the special reproduction without causing stress to the user who operates the client device Can be performed.

  Next, the best mode for carrying out the present invention will be described in detail with reference to the drawings. FIG. 1 shows a configuration diagram of a first embodiment of a moving image distribution system, a server device, and a client device according to the present invention. In the moving image distribution system of the present embodiment, the server device 10 and the client device 20 are connected via a network 30, and the server device 10 and the client device 20 can communicate bidirectionally via the network 30. It is configured.

  As shown in FIG. 1, the server apparatus 10 according to the present embodiment has a configuration that includes an encoded data holding unit 101, a resolution determination unit 102, and a communication unit 103. The encoded data holding unit 101 holds encoded data having various resolutions, and outputs the encoded data held in the resolution determining unit 102 and the resolution list. In this embodiment, scalable encoded data is used to reduce the amount of data to be stored. However, if a large amount of data may be used for data storage, a certain content is encoded for each resolution. A plurality of data may be held.

  The resolution determination unit 102 uses the data according to the data structure 1 requested by the client device 20 input from the communication unit 103 and the resolution list of the encoded data holding unit 101 to perform encoding that is output to the client device 20. Determine the resolution of the data. Also, the encoded data of the determined resolution is acquired from the encoded data holding unit 101 and output to the communication unit 103. This will be described in detail later.

  The communication unit 103 converts the encoded data output from the resolution determination unit 102 and output to the client device 20 into a protocol common to the client device 20 and outputs the same. In addition, data input from the client device 20 via the network 30 is converted into data conforming to the data structure 1 and output to the resolution determination unit 102.

  As shown in FIG. 1, the client device 20 of the present embodiment includes a communication unit 201, a decoding unit 202, a frame number control unit 203, a display device 204, an external command analysis unit 205, and a client request generation unit 206. It is configured. The communication unit 201 receives data distributed from the server device 10 via the network 30, converts it into encoded data, and outputs the encoded data to the decoding unit 202. In addition, the communication unit 201 converts the data along the data structure 1 input from the client request generation unit 206 into a protocol common to the server device 10 and outputs the same to the server device 10. The decoding unit 202 performs a decoding process on the encoded data input from the communication unit 201, and outputs the moving image data decoded by the decoding process to the frame number control unit 203.

  The frame number control unit 203 is input with moving image data of an arbitrary frame rate decoded by the decoding unit 202, and outputs the input moving image data to the display device 204. For example, assuming that the maximum frame rate of the display device is 60 fps and the frame rate of the decoded moving image data is 60 fps, the decoded moving image data is output as it is. When the maximum frame rate of the display device is 60 fps and the frame rate of the decoded moving image data is 120 fps, 60 fps is realized by outputting every other image. The display device 204 displays moving image data having an arbitrary frame rate input from the frame number control unit 203.

  The external command analysis unit 205 analyzes the content of the external command A from the outside of the client device 20 and outputs the analyzed result to the client request generation unit 206. Here, in the present embodiment, the external command A indicates a moving image playback command (playback / pause / stop / fast-forward / fast-reverse) issued by the user. In the present embodiment, a person who issues a command is a person, but the present invention is not limited to this. Further, the external command A issued by the user is played, paused, stopped, fast forwarded, and fast rewinded, but slow playback or the like may be added.

The client request generation unit 206 generates data according to the data structure 1 requested from the server device 10 according to the analysis result of the external command A input from the external command analysis unit 205, and sends the generated data to the communication unit 201. Output. Here, data along the data structure 1 is shown below.
[Play command (Play / Pause / Stop / Fast forward / Fast reverse), Special playback speed, Display device resolution] ... Data structure 1
Next, the operation of the server apparatus 10 of FIG. 1 will be described with reference to the flowchart of FIG. First, the server device 10 determines whether or not the client request data based on the external command A is received from the client device 20 via the network 30 in the communication unit 103 (step S11). The data is converted into data conforming to the data structure 1 and output to the resolution determination unit 102 (step S12).

  Subsequently, in the resolution determination unit 102, the server device 10 uses the data along the data structure 1 input from the communication unit 103 and the resolution list of the encoded data holding unit 101 to output to the client device 20. The resolution of the encoded data is determined, and the largest number of encoded data is acquired from the encoded data held in the encoded data holding unit 101 and output to the communication unit 103 (step). S13). The operation of the resolution determination unit 102 will be described in detail later.

  Subsequently, in the communication unit 103, the server device 10 converts the encoded data input from the resolution determination unit 102 into a protocol common to the client device 20, and then distributes the encoded data to the client device 20 via the network 30 (step). S14). When it is determined in step S11 that the client request data has not been received, it is determined that special reproduction is not performed, and encoded data having a predetermined resolution during normal reproduction is acquired from the encoded data holding unit 101. The generated data is distributed to the client device 20 via the communication unit 103 (step S15).

  Next, the operation of the resolution determination unit 102 in step S13 in FIG. 2 will be described in detail with reference to the flowchart in FIG. The resolution determination unit 102 determines the resolution of the encoded data to be output using the data along the data structure 1 from the client device 20 input from the communication unit 103 and the resolution list of the encoded data holding unit 101. Then, the encoded data of the determined resolution is acquired from the encoded data holding unit 101 and output to the communication unit 103.

  The resolution determination unit 102 branches based on the content of the playback command of the input data from the communication unit 103 (step S21). If the playback command is a playback / pause / stop normal playback command, the resolution determination unit 102 performs the process of step S22. If it is a fast-forward / fast-reverse special playback command, the process of step S23 is performed.

  In step S22, a normal playback command for playback / pause / stop is input, and the first process # 1 for generating data according to the data structure 2 shown below is performed, and the generated data is output. Step S25 is performed.

[Output data presence / absence flag, output resolution] ... Data structure 2
Here, in the first process # 1 of step S22, when the reproduction command is “reproduction”, the data structure is [there is output data, the display device resolution of the data according to the inputted data structure 1]. If the reproduction command is “pause” or “stop”, data of data structure 2 [no output data, (0, 0)] is generated.

  Step S23 is a second process # 2 performed when it is determined in step S21 that a fast-forward / fast-rewind playback command has been input. Data in accordance with the input data structure 1 (client request data) Table 1 is used to calculate the resolution of the encoded data to be output, using Table 1 that can calculate the special reproduction speed, the display device resolution (resolution of the display device 204), and the output resolution according to the special reproduction speed. .

上記の表１はクライアント装置２０からのクライアント要求データが示す特殊再生速度及び表示デバイス解像度とに応じて、従来よりも単位時間当たりの高速再生画像の枚数が多く、コンテンツの連続性を認識できる動画像符号化データの解像度を判断するために予め設定されている。

Table 1 above shows a moving image in which the number of high-speed playback images per unit time is larger than in the past and the continuity of content can be recognized according to the special playback speed and display device resolution indicated by the client request data from the client device 20 It is preset in order to determine the resolution of the image encoded data.

  For example, assuming that the special playback speed (hereinafter referred to as Tp) is 5 times, the display device resolution is a horizontal width W of “1920 pixels”, and a height H of “1080 pixels”, according to Table 1, from Table 1, Since 3 <Tp ≦ 10 ”, the output resolution is 960 (= W / 2 = 1920/2) horizontal width W ′ and 540 (= H / 2 = 1080/2) height H ′. And the output resolution is (960, 540). Note that the number of high-speed playback moving images displayed per unit time depends on the display capability (display resolution) of the display device. In the present embodiment, the resolution is calculated using Table 1, but a method of determining the resolution by changing Table 1 in a timely manner according to the status of the network 30 may be used.

  Step S24 following step S23 is a third process for correcting the resolution of the encoded data distributed to the client device 20 using the resolution calculated in step S23 and the resolution list of the encoded data holding unit 101. # 3. For example, assuming that the resolution calculated in step S23 is (960, 540) and the resolution list of the encoded data holding unit 101 is as shown in Table 2, the resolution equal to or lower than (960, 540) Is selected from the resolution list in Table 2, and the maximum resolution (720, 480) that can output a large number of moving images per unit time is determined as the resolution to be output, and [Output data exists, (720, 480 )] Is generated along the data structure 2.

  That is, in the present embodiment, the resolution determined in accordance with the special playback speed and the resolution of the display device is displayed per unit time among the encoded data held in the encoded data holding unit 101. This is the highest resolution that can output the largest number of high-speed playback moving images. In the present embodiment, the resolution held in the encoded data holding unit 101 is determined as the output resolution. However, if real-time processing is possible, the resolution calculated in step S23 is re-encoded or the like. May be determined as the output resolution.

  When the resolution determination unit 102 finishes the first process # 1 in step S22 or the third process # 3 in step S24, the data structure 2 generated in the process # 1 or # 3 is subsequently generated. The fourth process # 4 for generating encoded data along the data along the line is performed (step S25), and the process is output to the communication unit 103 and the process is terminated. In step S25, for example, if [output data exists, (720, 480)] is input, the encoded data holding unit 101 outputs encoded data having a resolution of (720, 480) to the communication unit 103. .

  Next, the operation of the client device 20 of FIG. 1 will be described with reference to the flowchart of FIG. First, the client device 20 determines whether or not the external command A is input (step S31). If the external command A is input, the process proceeds to step S32. If the external command A is not input, the process proceeds to step S35. Perform the process. When the external command A is input, the external command analysis unit 205 analyzes the content of the external command A, and outputs the analyzed result to the client request generation unit 206 (step S32).

  Subsequently, in the client request generation unit 206, the client request generation unit 206 generates client request data according to the data structure 1 requested to the server device 10 according to the analysis result of the external command A input from the external command analysis unit 205. The generated client request data is output to the communication unit 201 (step S33). The communication unit 201 converts client request data according to the data structure 1 input from the client request generation unit 206 into a protocol common to the server device 10 and outputs the same to the server device 10 via the network 30 (step S34). .

  On the other hand, if the external command A is not input, the process proceeds to step S35, where the communication unit 201 receives the data distributed from the server device 10 via the network 30, converts it into encoded data, and sends it to the decoding unit 202. Output. Subsequently, the decoding unit 202 performs a decoding process on the encoded data input from the communication unit 201, and outputs the moving image data decoded by the decoding process to the frame number control unit 203 (step S36).

  When the frame number control unit 203 in the client device 20 receives the moving image data of an arbitrary frame rate decoded by the decoding unit 202, the frame number control unit 203 outputs the input moving image data to the display device 204. It is displayed (step S37). At this time, the frame number control unit 203 controls the number of frames so that the frame rate of the decoded moving image data is equal to or lower than the maximum frame rate of the display device 204. The client device 20 repeats the operations of steps S32 to S34 or the operations of S35 to S37 until a predetermined end condition is satisfied based on the determination result of step S31 (step S38).

  As described above, in the present embodiment, when the client device 20 performs the special reproduction based on the command of the external command A, the client request data for the client device 20 to transmit the special reproduction command to the server device 10 is transmitted to the network. When the server device 10 receives the client request data indicating the special reproduction command, the data is encoded according to the special reproduction speed included in the client request data and the resolution of the display device. From the encoded data held in the data holding unit 101, the moving image data having the largest resolution with the largest number of reproduced images per unit time is read out at the special reproduction speed, and the server apparatus 10 receives the client apparatus via the network 30. 20 is distributed as encoded data for special playback. Since the ant device 20 can display a special reproduction image obtained by decoding a larger number of moving image data than the conventional one from the encoded data distributed from the server device 10, and thereby recognize the continuity of the content, The problem of not being able to recognize the continuity of the content that was, and the problem of lack of real-time characteristics when displaying a lot of moving image data can be solved, making the user to perform special playback without stress be able to.

  Next, a second embodiment of the present invention will be described with reference to the drawings. FIG. 5 shows a configuration diagram of a second embodiment of a moving image distribution system, a server device, and a client device according to the present invention. In the figure, the same components as those in FIG. In the moving image distribution system according to the second embodiment shown in FIG. 5, the server device 15 and the client device 20 are connected via the network 30, and the server device 15 and the client device 20 are connected via the network 30. It is configured to be able to communicate in both directions.

  As shown in FIG. 5, the server device 15 according to the present embodiment has a configuration including an encoded data holding unit 101, a resolution determination unit 102, a client capability control unit 104, and a communication unit 103, and the implementation shown in FIG. Compared with the server apparatus 10 in the form, the client capability control unit 104 is provided between the resolution determination unit 102 and the communication unit 103.

  The client capability control unit 104 is configured to display the resolution determined by the resolution determination unit 102, the special playback speed, and the client device 20 as shown in Table 3 of data in accordance with the data structure 1 ′ described later input from the communication unit 103. The resolution of the moving image data to be distributed to the client device 20 is corrected using the client decoding capability list in which the number of decoded frames of the decoding unit 202 is associated with the resolution of the moving image data.

  For example, assuming that the special playback speed is 30 × speed and the resolution determined by the resolution determination unit 102 is (720, 480), from the decoding capability list of the client device 20 shown in Table 3, Since the number of decoded frames is “24” and real-time decoding is not in time, the client capability control unit 104 determines the resolution (360, 480) when the number of decoded frames is “48” which is closest to “30”. The encoded data having the corrected resolution is acquired from the encoded data holding unit 101 and output to the communication unit 103.

  When the corrected resolution does not exist in the encoded data holding unit 101, encoded data equal to or lower than the resolution list in the encoded data holding unit 101 is output. In the present embodiment, the resolution is corrected using the decoding capability of the client device 20, but the resolution of encoded data to be output may be corrected using, for example, the bandwidth of the communication path. .

  As shown in FIG. 5, the client device 20 of this embodiment includes a communication unit 201, a decoding unit 202, a frame number control unit 203, a display device 204, an external command analysis unit 205, and a client request generation unit 206. Although this configuration is basically the same as that of the client device 20 of FIG. 1, the configuration of client request data generated by the client request generation unit 206 is slightly different from that of the first embodiment.

  Next, operation | movement of the server apparatus 15 of this Embodiment is further demonstrated with the flowchart of FIG. In the figure, the same processing steps as those in FIG. As illustrated in FIG. 6, when the server apparatus 15 receives client request data from the client apparatus 20 via the network 30 in the communication unit 103 (YES in step S11), the server apparatus 15 converts the data into data according to a data structure 1 ′ described later. Then, the data is output to the client capability control unit 104 and the resolution determination unit 102 (step S12).

  Subsequently, the server device 10 uses the data according to the data structure 1 ′ input from the communication unit 103 and the resolution list of the encoded data holding unit 101 in the resolution determination unit 102, as shown in FIG. The resolution of the encoded data to be output to the client device 20 is determined according to the flowchart, the encoded data having the determined resolution is acquired from the encoded data holding unit 101, and the generated data is output to the client capability control unit 104 (step) S13).

  Subsequently, in the server device 10, the client capability control unit 104 shows the resolution determined by the resolution determination unit 102, the special playback speed, and the data along the data structure 1 ′ input from the communication unit 103 in Table 3 below. Using the list of client decoding capabilities, the resolution of the moving image data distributed to the client device 20 is corrected as described above (step S16).

  Then, the server device 15 distributes the encoded data corrected in the client capability control unit 104 to the client device 20 via the network 30 that is output after being converted into a common protocol with the client device 20 in the communication unit 103 (step). S14).

  Next, the operation of the client device 20 of the present embodiment will be described with reference to the flowchart of FIG. In the figure, the same processing steps as those in FIG. 4 are denoted by the same reference numerals, and the description thereof is omitted. The client device 20 of FIG. 5 performs substantially the same operation as that of the first embodiment, but the operation differs from the client request generation unit 206 in step S32 of the external command A input from the external command analysis unit 205. According to the analysis result, client request data is generated along the data structure 1 ′ requested from the server device 15, and the generated client request data is output to the communication unit 201 (step S41 in FIG. 7).

  Here, data along the data structure 1 'is shown below.

[Playback commands (playback / pause / stop / fast forward / fast reverse), special playback speed, display device resolution, client decoding capability] ... Data structure 1 '
The data structure 1 ′ is characterized in that data indicating client decoding capability is added as compared with the data structure 1. Here, the client decoding capability is a capability indicating how many encoded data of an arbitrary resolution can be decoded per second, and can be expressed by a list in which the resolution and the number of decoded frames shown in Table 3 are associated with each other. .

  In the present embodiment, a list is used to indicate the client decoding capability. However, for example, the server device 15 inquires the client device 20 about the decoding capability, and the decoding unit 202 implemented by the client device 20 includes the server device 15. It is also possible to notify the decoding capability to the method. After that, the communication unit 201 in FIG. 5 converts the client request data according to the data structure 1 ′ input from the client request generation unit 206 into a protocol common to the server device 10, and sends it to the server device 15 via the network 30. This is output (step S34 in FIG. 7).

  As described above, in the present embodiment, when the client device 20 performs the special reproduction based on the command of the external command A, the client device 20 includes the client request data for transmitting the special reproduction command to the server device 15 in the client request data. When the server apparatus 15 receives the client request data indicating the special reproduction command, the data is output according to the special reproduction speed included in the client request data. The resolution of the encoded data is determined, and the determined resolution is corrected by using the list of client decoding capabilities shown in Table 3 of the data along the data structure 1 ′. The server device 15 specially reproduces the encoded data to the client device 20 via the network 30. Because you be delivered as coded data, the client device 20 can display the special reproduction image in real time by decoding the encoded data distributed from the server device 15.

  The present invention is not limited to the above embodiment, and the server devices 10 and 15 and the client device 20 can be realized by a computer, and the present invention includes a computer program for operating the computer. To do. In this case, the computer program may be taken into the computer from a recording medium, distributed via a network, taken into the computer, or further taken into the computer as firmware. Of course, the present invention is also applicable when the server device and the client device are directly connected by a cable.

BRIEF DESCRIPTION OF THE DRAWINGS It is a block diagram of 1st Embodiment of the moving image delivery system of this invention, a server apparatus, and a client apparatus. It is a flowchart for operation | movement description of the server apparatus in FIG. It is a flowchart for operation | movement description of the resolution determination part in FIG. 2 is a flowchart for explaining the operation of the client device in FIG. 1. It is a block diagram of 2nd Embodiment of the moving image delivery system of this invention, a server apparatus, and a client apparatus. 6 is a flowchart for explaining the operation of the server device in FIG. 5. 6 is a flowchart for explaining the operation of the client device in FIG. 5. It is a figure which shows an example of a structure of GOP. 10 is an explanatory diagram of a special reproduction method described in Patent Document 1. FIG. 10 is an explanatory diagram of a special reproduction method described in Patent Document 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 15 Server apparatus 20 Client apparatus 30 Network 101 Encoded data holding part 102 Resolution determination part 103, 201 Communication part 104 Client capability control part 202 Decoding part 203 Frame number control part 204 Display apparatus 205 External command analysis part 206 Client request Generator A External instruction

Claims (6)

In a moving image distribution system for distributing moving image encoded data from a server device to a client device via a network,
The client device is
Data generation means for generating client request data for transmitting a special reproduction command specifying a special reproduction speed input from the outside and resolution information indicating the resolution of a display device for displaying a moving image, and transmitting the client request data to the server device When,
Decoding means for decoding the moving image encoded data received from the server device to generate moving image data;
Control means for controlling the display rate of the moving image data output from the decoding means to be equal to or lower than a maximum display rate that can be displayed on the display device, and outputting the controlled moving image data to the display device. ,
The server device is
Encoded data holding means holding a plurality of moving image encoded data having different resolutions;
The client request data transmitted from the client device via the network is received, and held in the encoded data holding unit according to the special reproduction speed indicated by the received client request data and the resolution of the display device Resolution determining means for determining moving image encoded data having the highest number of reproduced images per unit time at the special reproduction speed from the moving image encoded data being
A moving image distribution system comprising: transmission means for reading moving image encoded data having a resolution determined by the resolution determining means from the encoded data holding means and transmitting the same to the client device. In a moving image distribution system for distributing moving image encoded data from a server device to a client device via a network,
The client device is
A special playback command specifying a special playback speed input from the outside, resolution information indicating the resolution of a display device for displaying a moving image, and how many pieces of encoded data of an arbitrary resolution can be decoded per unit time in the own device. Data generation means for generating client request data for transmitting the decoding capability information indicating the data and transmitting it to the server device;
Decoding means for decoding the moving image encoded data received from the server device to generate moving image data;
Control means for controlling the display rate of the moving image data output from the decoding means to be equal to or lower than a maximum display rate that can be displayed on the display device, and outputting the controlled moving image data to the display device. ,
The server device is
Encoded data holding means holding a plurality of moving image encoded data having different resolutions;
The client request data transmitted from the client device via the network is received, and held in the encoded data holding unit according to the special reproduction speed indicated by the received client request data and the resolution of the display device Resolution determining means for determining moving image encoded data having the highest number of reproduced images per unit time at the special reproduction speed from the moving image encoded data being
Based on the decoding capability information indicated by the received client request data, the moving image encoded data having the resolution determined by the resolution determining unit read from the encoded data holding unit is set to a resolution that can be decoded by the client device. Correction means for correcting;
A moving image distribution system comprising: transmission means for transmitting the encoded moving image data whose resolution is corrected by the correcting means to the client device. In a server device that distributes moving image encoded data to a client device via a network,
Encoded data holding means holding a plurality of moving image encoded data having different resolutions;
Client request data for transmitting a special reproduction command specifying the special reproduction speed input from the outside of the client device and resolution information indicating the resolution of the display device for displaying a moving image, generated in the client device Of the moving image encoded data held in the encoded data holding means according to the special reproduction speed indicated by the received client request data and the resolution of the display device. Resolution determining means for determining moving image encoded data having the highest number of reproduced images per unit time at the special reproduction speed,
A server device comprising: a transmission unit that reads out the encoded moving image data having the resolution determined by the resolution determination unit from the encoded data holding unit and transmits the data to the client device. In a server device that distributes moving image encoded data to a client device via a network,
Encoded data holding means holding a plurality of moving image encoded data having different resolutions;
A special reproduction command specifying the special reproduction speed input from the outside of the client device, resolution information indicating the resolution of the display device for displaying a moving image, and an arbitrary resolution in the client device. Client request data for transmitting decoding capability information indicating how many pieces of moving image encoded data can be decoded per unit time is received via the network, and the special reproduction indicated by the received client request data Depending on the speed and the resolution of the display device, the moving image having the highest number of reproduced images per unit time at the special reproduction speed among the encoded moving image data held in the encoded data holding means. Resolution determining means for determining image encoded data;
Based on the decoding capability information indicated by the received client request data, the moving image encoded data having the resolution determined by the resolution determining unit read from the encoded data holding unit is set to a resolution that can be decoded by the client device. Correction means for correcting;
A server device comprising: transmission means for transmitting the moving image encoded data whose resolution has been corrected by the correction means to the client device. In a client device that generates moving image data by decoding moving image encoded data distributed from a server device via a network,
Data generation means for generating client request data for transmitting a special reproduction command specifying a special reproduction speed input from the outside and resolution information indicating the resolution of a display device for displaying a moving image, and transmitting the client request data to the server device When,
The special reproduction determined from the moving image encoded data held in the server device according to the special reproduction speed indicated by the client request data received by the server device and the resolution of the display device. Decoding means for receiving moving image encoded data having the highest number of reproduced images per unit time at a speed from the server device, and decoding the received moving image encoded data to generate moving image data;
Control means for controlling a display rate of the moving image data output from the decoding means to be equal to or lower than a maximum display rate that can be displayed on the display device, and outputting the controlled moving image data to the display device. A client device. In a client device that distributes moving image encoded data generated by a server device via a network and generates moving image data by decoding the distributed moving image encoded data,
A special playback command specifying a special playback speed input from the outside, resolution information indicating the resolution of a display device for displaying a moving image, and how many pieces of encoded data of an arbitrary resolution can be decoded per unit time in the own device. Data generation means for generating client request data for transmitting the decoding capability information indicating the data and transmitting it to the server device;
The special playback determined from the moving image encoded data held in the server device according to the special playback speed indicated by the client request data received by the server device and the resolution of the display device. The moving image encoded data having the resolution obtained by correcting the moving image encoded data having the largest number of reproduced images per unit time at a speed based on the decoding capability information indicated by the received client request data, Decoding means received from the server device and decoding the received moving image encoded data to generate moving image data;
Control means for controlling a display rate of the moving image data output from the decoding means to be equal to or lower than a maximum display rate that can be displayed on the display device, and outputting the controlled moving image data to the display device. A client device.

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