JP5675164B2 - Transmission device, transmission method, and program - Google Patents

Description

  The present invention relates to a moving image data transmission method.

  In recent years, streaming technology for transmitting and receiving moving image data in real time via a network, such as a network camera and a video conference system, has been put into practical use. In such distribution of moving image data, in order to maintain the video quality, the moving image encoding rate is controlled in accordance with the transmission speed and the line condition (see Patent Document 1), or the frame is thinned out. (See Patent Document 2).

Special registration 036999910 Special registration No. 02555685

  However, when moving image data is transmitted to a plurality of receiving devices, depending on the communication status of each receiving device, moving image data that does not match the communication status may be transmitted.

  For example, when moving image data is transmitted to the first receiving device and the second receiving device, if the encoding rate of the moving image data is lowered due to the deterioration of the communication status with the first receiving device, There was a possibility that the image quality of the moving image displayed on the second receiving device would be lowered more than necessary.

  Further, for example, if the frame rate of the moving image data is lowered due to the deterioration of the communication status with the first receiving device, the frame rate of the moving image displayed on the second receiving device may be lowered more than necessary. was there.

  Further, for example, if the encoding rate is controlled for each receiving apparatus according to the communication status of each receiving apparatus, there is a possibility that the load of rate control becomes large.

  The present invention has been made in view of the above-mentioned problems, and the object thereof is more suitable for the communication status of each receiving apparatus while suppressing the load on transmission when moving image data is transmitted to a plurality of receiving apparatuses. It is to be able to send video data.

In order to achieve the above object, the transmission apparatus of the present invention has the following configuration, for example. That is, a transmission device that transmits encoded video data to a plurality of reception devices, the first transmission data rate that can be transmitted to the first reception device, and the transmission to the second reception device. a second transmission data rate obtaining means for obtaining possible, in accordance with the difference of the first and second transmission data rate, a control means for performing the encoding rate control and frame thinning control, the first If 1 and the second value corresponding to a difference in transmission data rate is greater than the threshold value, the one of the first and second transmission data rate, the lower second transmission data rate corresponding to the previous SL second the receiver, a moving image data frame skipping, is determined as the receiver moving image data composed of decodable intra frame is transmitted without reference to other video frames, the first and second 2 Among the transmission data rates, the first receiving device corresponding to the higher first transmission data rate is an interframe that is video data that is not frame-decimated and that can be decoded by referring to another video frame. And moving image data composed of the intra frame is determined as a receiving device to be transmitted, and a data rate of moving image data including the inter frame and the intra frame transmitted to the first receiving device is the first rate. 1 and the intra frame data rate of the moving image data transmitted to the second receiving device does not exceed the second transmission data rate. An encoding rate of the moving image data including a frame and an inter frame is determined, and the first transmission and the second transmission When the value corresponding to the difference in data rate is less than the threshold, the coding rate is determined based on the lower second transmission data rate of the first and second transmission data rates, and the determination is performed. to have a control means decides to send to without the first and second receiver apparatus to the video data frame skipping the encoded with encoded rate.

  According to the present invention, when moving image data is transmitted to a plurality of receiving devices, it is possible to transmit moving image data that is more suitable for the communication status of each receiving device while suppressing the load on transmission.

3 is a block diagram illustrating a functional configuration example of a transmission device 100. FIG. 3 is a flowchart showing processing of a transmission device 100. It is a figure which shows an example of the connection form of the transmitter 100 and several receivers. It is a figure which shows the moving image data which the transmitter 100 transmits to a receiver.

  Hereinafter, the present invention will be described in detail based on preferred embodiments with reference to the accompanying drawings. The configurations shown in the following embodiments are merely examples, and the present invention is not limited to the illustrated configurations.

<Embodiment 1>
FIG. 1 is a block diagram illustrating a functional configuration example of the transmission apparatus according to the present embodiment.

  As illustrated in FIG. 1, the transmission device 100 includes an encoding unit 102, a packet generation unit 103, a QoS control unit 104, a data buffer 105, a communication control unit 106, a transmission rate calculation unit 107, and a communication interface 108. The QoS control unit 104 includes a thinning unit 110 and a rate control unit 111. The data buffer 105 stores data to be transmitted / received to / from the receiving device. The transmission device 100 is a transmission device that transmits encoded moving image data to a reception device. The transmission apparatus 100 of this embodiment is connected to a video input apparatus 101 that inputs video and a transmission path 109.

  The video input device 101 is a device for inputting video such as a video camera or a web camera. However, the video input device 101 may be integrated with the transmission device 100.

  The transmission device 100 can be realized by a personal computer, a workstation, a notebook PC, various home appliances with a built-in computer, a game machine, a mobile phone, a digital video camera, a digital camera, or a combination of these devices.

  The transmission path 109 is a transmission path represented by various networks. In the present embodiment, the transmission path 109 is a network for transmitting and receiving various packets including a moving image data packet to and from the receiving apparatus.

  The encoding unit 102 compresses and encodes the moving image data input from the video input device 101 using the MPEG-4 Video system. The moving image data input from the video input device 101 has a large amount of data to be distributed as it is, and is therefore compressed and encoded by the encoding unit 102 before distribution. The encoding unit 102 inputs the compression-coded moving image data to the packet generation unit 103 in units of frames.

  The packet generation unit 103 packetizes the moving image data input from the encoding unit 102 and stores the packetized data in the data buffer 105. In the present embodiment, MPEG-4 Video is used as an encoding method for moving image data, and RTP (Real-time Transport Protocol) is used as a transfer protocol for encoded moving image data. Therefore, the packet generation unit 103 packetizes moving image data encoded in accordance with IETF RFC3016 that defines the RTP payload format of MPEG-4 Video encoded moving image data.

  The communication control unit 106 transmits the RTP packet (encoded moving image data) stored in the data buffer 105 to a predetermined destination (receiving device) via the communication interface 108.

  The transmission rate calculation unit 107 calculates the data rate of moving image data that can be transmitted to the receiving device in accordance with the reception status notification transmitted by the receiving device. In this embodiment, an RTCP (RTP Control Protocol) receiver report is used as the reception status notification. Also, the transmission rate calculation unit 107 calculates a value (for example, difference, variance value, standard deviation) according to the difference in data rate that can be transmitted to each receiving apparatus. In this embodiment, a case will be described in which a statistical value (dispersion) is calculated according to the difference in data rate that can be transmitted to each receiving apparatus.

  The QoS control unit 104 controls the coding rate of the moving image data and the frame rate according to the statistical value (dispersion value) calculated by the transmission rate calculation unit 107. Details of the processing of the QoS control unit 104 will be described later.

  Next, the process of the transmission apparatus 100 of this embodiment is demonstrated using FIG. FIG. 2 is a flowchart illustrating an example of processing performed by the transmission apparatus 100 according to the present embodiment. The transmission apparatus 100 according to the present embodiment executes the process shown in the flowchart of FIG. 2 during transmission of moving image data to a plurality of reception apparatuses.

  The transmission rate calculation unit 107 of the transmission device 100 acquires a reception status notification from each reception device (S201). That is, in step S201, the transmission rate calculation unit 107 acquires a reception status notification indicating the reception status of the encoded moving image data from each of the plurality of reception devices. The transmission rate calculation unit 107 of this embodiment receives an RTCP receiver report as a reception status notification.

  The transmission rate calculation unit 107 calculates the data rate (transmission rate) of the moving image data that can be transmitted to each receiving device based on the reception status notification acquired from each receiving device (S202). That is, in S202 (acquisition procedure), the data rate of moving image data that can be transmitted to each receiving device is acquired. The transmission rate calculation unit 107 calculates a first data rate that can be transmitted to the first receiving device based on the reception status notification received from the first receiving device, and receives the receiving status received from the second receiving device. Based on the notification, a second data rate that can be transmitted to the second receiving device is calculated.

  The transmission rate calculation unit 107 can calculate a data rate (transmission rate) that can be transmitted to the receiving device based on the packet loss rate and time information (RTT) included in the reception status notification (RTCP receiver report). it can. For example, if a packet loss rate is 0% when moving image data is transmitted at 10 Mbps and a packet loss rate is 10% when transmitted at 11 Mbps to a certain receiving device, transmission to the receiving device is possible. The data rate is calculated as 10 Mbps. That is, the transmission rate calculation unit 107 acquires error information (packet loss rate) related to moving image data that has not been normally received for each of the plurality of receiving devices from the reception status notification. Then, based on the encoding rate of the moving image data transmitted to each of the plurality of receiving apparatuses and the error information, a data rate that can be transmitted to each of the plurality of receiving apparatuses is calculated.

  As another method for calculating the transmission rate, for example, there is a method using a round trip time (RTT). The transmission rate calculation unit 107 calculates RTT from the reception status notification transmitted by the receiving device, and calculates the transmission rate. That is, the transmission rate calculation unit 107 calculates the communication time (RTT) between each receiving device and the transmitting device based on the transmission time of the receiving status notification by the receiving device and the acquisition time of the receiving status notification by the transmitting device. get. Then, based on the acquired communication time and the encoded rate of the transmitted moving image data, a data rate that can be transmitted to each of the plurality of receiving devices is calculated.

  However, the transmission rate calculation method is not limited to the above method, and can be calculated using, for example, jitter. In this embodiment, the transmission rate is determined in response to reception of the receiver report. However, the present invention is not limited to this configuration. For example, the transmission rate may be acquired at a timing according to designation from the user or at regular intervals. In addition, when the transmission rate is notified from the reception device, the transmission rate calculation unit 107 acquires the value as the transmission rate of the reception device.

  Also, the transmission rate calculation unit 107 calculates a value corresponding to the difference in the calculated data rate in S202. The transmission rate calculation unit 107 of the present embodiment is a value corresponding to the difference between the first data rate that can be transmitted to the first receiving device and the second data rate that can be transmitted to the second receiving device. The variance value is calculated as The data rate and dispersion value calculated by the transmission rate calculation unit 107 are passed to the QoS control unit 104.

  The QoS control unit 104 determines whether or not the data rate (transmission rate) that can be transmitted to each receiving apparatus is the same based on the dispersion value passed from the transmission rate calculation unit 107 (S203). That is, the QoS control unit 104 compares the variance value calculated by the transmission rate calculation unit 107 with a threshold value. If the variance value is equal to or greater than the threshold value, it is determined that the transmittable data rate for each receiving apparatus is not equal, and the process proceeds to S205. On the other hand, if the variance value is lower than the threshold value, it is determined that the transmittable data rate for each receiving apparatus is the same, and the process proceeds to S204.

  In S204, the rate control unit 111 according to the present embodiment controls the encoding rate of moving image data in accordance with the lowest data rate among the data rates calculated for each receiving apparatus. Note that the thinning unit 110 does not control the frame rate for each receiving apparatus in S204. As described above, when the difference (variation) in the data rate (transmission speed) that can be transmitted to each receiving apparatus is small, the same moving image data is transmitted to each receiving apparatus by controlling the encoding rate according to the receiving apparatus having a low transmission speed. By transmitting to, the load on the transmission process can be reduced.

  On the other hand, in S205 (control procedure), the thinning unit 110 performs frame thinning of moving image data. The thinning unit 110 according to this embodiment obtains an average value of transmission rates of the respective receiving apparatuses. And it classify | categorizes into the receiver with a transmission rate higher than an average value, and the receiver with a transmission rate lower than an average value. The thinning unit 110 performs frame thinning of moving image data to be transmitted to a receiver having a transmission rate lower than the average value according to the magnitude of the difference from the lowest transmission rate among the transmission rates higher than the average value. Do. That is, the moving image data in which the data rate is controlled differently is transmitted between the receiving device having a transmission rate higher than the average value and the receiving device having a transmission rate lower than the average value.

  For example, a case where moving image data is transmitted to the first, second, and third receiving devices will be described. In this example, the third data rate that can be transmitted to the third receiving device is the highest, the second data rate that can be transmitted to the second receiving device is the lowest, and the second data rate that can be transmitted to the first receiving device. Assume that the data rate of 1 is higher than the intermediate value of the second and third data rates. In this case, the thinning unit 110 determines a frame thinning interval of moving image data to be transmitted to the second receiving device based on the difference between the first and second data rates in S205. That is, it is determined to transmit all three types of frames of I frame, P frame, and B frame defined by MPEG-4 Video to the first and third receiving apparatuses.

  Also, in this example, when the difference between the first and second data rates is small, moving image data in which only B frames are thinned out of I, P, and B frames is transmitted to the second receiving apparatus. Decide that. On the other hand, when the difference between the first and second data rates is large, it is determined to transmit moving image data obtained by thinning out the P and B frames out of the I, P and B frames to the second receiving apparatus. To do.

  The I frame is an intra frame that can be decoded by the receiving apparatus without referring to other frames. The P frame is an inter frame that can be decoded by the receiving apparatus by referring to a past frame. The B frame is an inter frame that can be decoded by the receiving apparatus by referring to the past and future frames.

  That is, when the variance is equal to or greater than the threshold, the thinning unit 110 does not transmit a part of the moving image data (P and B frames) to be transmitted to the first receiving device to the second receiving device in S205 (control procedure). To control.

  Subsequently, the QoS control unit 104 determines whether the encoding rate after frame thinning is an appropriate encoding rate (S206). That is, the QoS control unit 104 determines that the encoding rate after frame decimation of video data compressed and encoded according to the lowest transmission rate (first data rate) among the transmission rates higher than the average value is the average value. It is determined whether it is higher than the following transmission rates.

  For example, when it is determined to transmit only an I frame to the second receiving device, among video data compressed and encoded based on a first data rate that can be transmitted to the first receiving device, It is determined whether the encoding rate of only the I frame is higher than the second data rate. Also, for example, when it is determined to transmit I and P frames to the second receiving apparatus, only the I and P frames of the moving image data compressed and encoded based on the first data rate are included. It is determined whether the encoding rate is higher than the second data rate. If the coding rate after frame decimation is higher than the second data rate, the process proceeds to S207, and if not, the process proceeds to S208.

  In S207, the rate control unit 111 controls the encoding rate in accordance with the data rate that can be transmitted to the receiving apparatus having a low transmission rate. For example, when the encoding rate of only the I frame of the moving image data compressed based on the first data rate is higher than the second data rate, the rate control unit 111 sets the image quality of the I frame to the second data rate. Lower based on. At this time, the image quality of the P and B frames is increased. By doing so, it is possible to reduce packet loss in the second receiving device while reducing deterioration in image quality in the first and third receiving devices.

  In the present embodiment, the intra-frame coding rate is reduced in S207. However, for example, the intra-frame interval may be increased. That is, when the statistical value (dispersion value) is equal to or greater than the threshold, the coding rate of the moving image data excluding the inter frame, and the coding rate determined using the first data rate is the second data rate. If it is higher, the interval of appearance of intra frames may be increased.

  The thinning unit 110 determines whether the motion of the moving image data after the frame thinning in S205 is smooth. For example, the decimation unit 110 determines that the motion is not smooth if the frame rate after frame decimation is lower than a threshold (2 fps (frame per sec)), and proceeds to S209. That is, the thinning unit 110 determines whether or not the frame rate of moving image data to be transmitted to the second receiving device to which no inter frame is transmitted is lower than a predetermined frame rate. Even if the threshold of the frame rate is a fixed value, it can be made variable according to the presence or absence of motion of the moving image, or can be specified by the user. For example, when the motion of the moving image is large, the threshold of the frame rate can be increased, and when the motion is small, the threshold can be decreased.

  If it is determined in S208 that the motion is not smooth (the frame rate is less than the threshold value), the QoS control unit 104 transmits a GOP configuration change request to the encoding unit 102 to reduce the I-frame interval (S209). Return to S204. The encoding unit 102 that has received the GOP configuration change request from the QoS control unit 104 changes the GOP configuration in accordance with the request. That is, the QoS control unit 104 narrows the intra-frame appearance interval when it is determined that the frame rate of the moving image data to be transmitted to the second receiving device to which no inter frame is transmitted is lower than the predetermined frame rate.

On the other hand, if it is determined in S208 that the motion is smooth (the frame rate is equal to or greater than the threshold), the QoS control unit 104 sets the lowest transmission rate among the transmission rates higher than the average value of the transmission rates of the receiving apparatuses. Based on the control (S2 10 ), the process is terminated. In this example, the encoding rate of moving image data is controlled based on the first data rate (the transmission speed of the first receiving device). 2 may be started in response to reception of the reception status notification, may be performed at a timing according to user designation, or may be performed every predetermined period.

  In this embodiment, when the statistical value (dispersion value) is higher than the threshold value, the coding rate is controlled based on the lowest transmission rate among the transmission rates higher than the average value of the transmission rates of the receiving apparatuses. In the above description, the frame rate is controlled according to the difference from the transmission rate. However, it is not limited to this form. For example, the coding rate may be controlled based on the highest transmission rate among the transmission rates of each receiving apparatus, and the frame rate may be controlled according to the difference from the transmission rate.

  Next, processing of the entire system of this embodiment will be described with reference to FIGS. 3 and 4. FIG. 3 is a diagram illustrating an example of a connection form and a transmission rate between the transmission device 100 and a plurality of reception devices (301 to 303).

  The transmission device 100, the first reception device 301, the second reception device 302, and the third reception device 303 are connected via a network 304 (corresponding to the transmission path 109 in FIG. 1). Further, the transmission rate between the transmission device 100 and the first reception device 301 is 9 Mbps, the transmission rate between the transmission device 100 and the third reception device 303 is 10 Mbps, and each transmission rate is constant. . That is, if the transmitting apparatus 100 transmits moving image data with an encoding rate of 9 Mbps or less to the first receiving apparatus 301, it is expected that no packet loss will occur in the communication path. On the other hand, the transmission rate between the transmission device 100 and the second reception device 302 varies between 512 kbps and 9 Mbps depending on the line condition.

  FIG. 4 is a diagram illustrating a relationship between moving image data encoded by the encoding unit 102 of the transmission device 100 and moving image data transmitted to the second reception device 302 over time.

  In the figure, 401 indicates the change in the transmission rate of the second receiving apparatus 302 over time. The transmission rate from time t1 to time t2 is 9 Mbps, the transmission rate from time t3 to time t4 is 1 Mbps, and the transmission rate from time t5 to time t6 is 512 kbps. In FIG. 4, transmission speeds before time t1, between time t2 and time t3, between time t4 and time t5, and between time t5 and time t6 are not shown.

  In the figure, reference numeral 402 denotes the size of each frame encoded by the encoding unit 102. In the figure, 403 indicates the size of each frame transmitted to the second receiving apparatus 302. Frames encoded at times t1, t2, t3, t4, t5, and t6 are intra frames, and frames encoded at other times are inter frames. There are frames before time t1, between time t2 and time t3, between time t4 and time t5, and between time t5 and time t6, but these frames are not shown in FIG. In the present embodiment, each frame indicated by 402 is transmitted to the first and third receiving apparatuses 301.

  The transmission rate between time t1 and time t2 is 9 Mbps for the first receiving device 301, 9 Mbps for the second receiving device 302, and 10 Mbps for the third receiving device 303. In this section, it is determined that the transmission rates of the first receiving device 301, the second receiving device 302, and the third receiving device 303 are the same (S203). Therefore, the moving image encoding rate is controlled in accordance with the transmission rate (9 Mbps) of the receiver having the lowest transmission rate (S204). Specifically, as illustrated in 402 of FIG. 4, the size of the intra frame is controlled to r4 and the size of the inter frame is set to r1, and the same moving image data is transmitted to each receiving device.

  The transmission rate between time t3 and time t4 is 9 Mbps for the first receiving device 301, 1 Mbps for the second receiving device 302, and 10 Mbps for the third receiving device 303. In this section, it is determined that the transmission rates of the plurality of receiving apparatuses (301 to 303) are not equal (there is variation) (S203). Then, as shown at 403, only the intra frame is transmitted to the second receiving apparatus 302 having the lowest transmission rate. On the other hand, all moving image frames are transmitted to the first receiving device 301 and the third receiving device 303.

  The transmission rate between time t5 and time t6 is 9 Mbps for the first receiving device 301, 512 kbps for the second receiving device 302, and 10 Mbps for the third receiving device 303. In this section, it is determined in S203 that the transmission rates of the plurality of receiving apparatuses (301 to 303) are not equal (there is variation) (S203). In step S205, it is determined that only the intra frame is transmitted to the second receiving apparatus. Furthermore, in S206, the transmission rate of the third receiving apparatus between time t5 and t6 is the encoding rate of only the intra frame of the moving image data determined based on the transmission speed (9 Mbps) of the first receiving apparatus 301. It is determined that it is higher than (512 kbps). Therefore, the rate control unit 111 performs control so that the intra-frame coding rate is lower than that based on the transmission rate (9 Mbps) of the first reception device 301. Further, in this case, the rate control unit 111 controls the interframe coding rate to increase.

  Therefore, the moving image data transmitted to the second receiving apparatus 302 is only an intra frame having a frame size r3 smaller than the frame size r4, as indicated by 403. The frame size r3 is a frame size calculated by the rate control unit 111 based on the transmission rate (512 kbps) of the second receiving apparatus 302. On the other hand, an intra frame of frame size r3 and an inter frame of frame size r2 from time t5 to time t6 in 402 are transmitted to first receiving device 301 and third receiving device 303. Here, the frame size r2 is a frame size calculated by the rate control unit 111 based on the transmission speed (9 Mbps) of the first receiving apparatus 301 and the frame size r3 of the intra frame.

  As described above, the transmission device 100 according to the present embodiment calculates the data rate (transmission speed) that can be transmitted to the reception device for each of the plurality of reception devices based on the reception status notification from the reception device. Then, a value corresponding to the difference in transmission speed is calculated. When the calculated value is equal to or greater than the threshold, the coding rate is controlled based on the lowest transmission rate among the transmission rates higher than the average transmission rate, and based on the transmission rate lower than the average value. Thus, the frame rate of each receiving apparatus is controlled. On the other hand, when the calculated value is lower than the threshold value, the moving image data encoded based on the lowest transmission rate is transmitted to each receiving device. In this embodiment, the example in which the variance value of each transmission rate is used as the value corresponding to the difference in transmission rate has been described. However, for example, a difference between the transmission rates, a standard deviation, or the like may be used.

  In this way, when moving image data is transmitted to a plurality of receiving devices, the load on the transmission process can be reduced as compared with the case where individual rate control is performed, and according to the communication status of each receiving device. Video data can be sent.

<Other embodiments>
In the above-described embodiment, the transmission device 100 has a function of encoding moving image data. However, the encoding unit 102 and the transmission device 100 may be separate devices.

  In the above-described embodiment, the MPEG-4 Video method is used as the moving image data encoding method, and RTP is used as the moving image data transfer protocol. However, as encoding methods of moving image data, for example, MPEG-2 or H.264 is used. A similar encoding scheme that performs encoding using an inter-frame predictive encoding scheme such as H.264 can be used. Also, the moving image data transfer protocol is not limited to RTP, and other protocols in the same layer or other protocols in the OSI reference model can be used.

  In the above-described embodiment, the transmission device 100 has a function of calculating the transmission rate. However, the transmission rate calculation unit 107 and the transmission device 100 may be separate devices, and an external measuring instrument. It is also possible to use communication band information from

  The present invention can also be realized by executing the following processing. That is, software (program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU, or the like) of the system or apparatus reads the program. It is a process to be executed.

Claims (11)

A transmitting device that transmits encoded video data to a plurality of receiving devices,
A first transmission data rate that can be transmitted to the first receiving apparatus, an acquisition unit configured to acquire a second transmission data rate that can be transmitted to the second receiving device,
Control means for performing coding rate control and frame decimation control according to a difference between the first and second transmission data rates , wherein a value according to the difference between the first and second transmission data rates is a threshold value. for more than the value, one of the first and second transmission data rate, the receiving device before Symbol of the second corresponding to a lower second transmission data rate, a moving image data frame thinning, other The first transmission data that is higher than the first transmission data rate and the second transmission data rate is determined as a receiving device that transmits the moving image data including the intra frames that can be decoded without referring to the moving image frame. The first receiving device corresponding to the rate is transmitted to the interframe and the intratraffic that are the moving image data that is not frame-decimated and can be decoded by referring to another moving image frame. A video data rate including the inter frame and the intra frame transmitted to the first receiving device is determined as a receiving device to which the moving image data including The intra frame so that the transmission data rate does not exceed and the data rate of the intra frame transmitted to the second receiving device of the moving image data does not exceed the second transmission data rate. An encoding rate of the moving image data including an inter frame is determined, and when a value corresponding to a difference between the first and second transmission data rates is less than the threshold, the first and second transmission data rates Of these, a moving picture encoded at the determined encoding rate while determining the encoding rate based on the lower second transmission data rate Transmitting apparatus characterized by chromatic and control means decides to send the over data to the first and second receiving device without frame thinning. Frame rate of the intra-frames constituting the moving image data the frame thinning has determining means for determining whether less than a predetermined frame rate,
Wherein, when the frame rate of the intra-frames constituting the moving image data the frame thinning is determined by low and said determining means than the predetermined frame rate, and performs control for increasing the frame rate of the intra-frame In addition, the data rate of the moving image data including the intra frame and the inter frame after the control to be transmitted that is transmitted to the first receiving device does not exceed the first transmission data rate, and the control is performed after the control. And determining the post-control encoding rate so that a data rate of the intra frame transmitted to the second receiving device does not exceed the second data rate. The transmission device according to claim 1 . The first and the value corresponding to the difference between the second transmission data rate, the transmission device according to claim 1 or 2, characterized in that a variance of the first and second transmission data rate. The acquisition means includes
Receiving means for receiving a reception status notification indicating the reception status of the encoded video data from each of the first and second receiving devices;
On the basis of the first and reception status notification acquired from the second receiving apparatus, according to claim 1 to 3, characterized in that it has a calculation means for calculating said first and second transmission data rate The transmission device according to any one of claims. The acquisition means acquires a transmission data rate corresponding to the reception status of moving image data from each of the first receiving device, the second receiving device, and the third receiving device that receives moving image data from the transmitting device. ,
When the variance value of the first, second, and third transmission data rates corresponding to the first, second, and third receiving apparatuses is less than the threshold value, the control unit is configured to perform the first, second, And a coding rate is determined based on the lowest transmission data rate among the third transmission data rates,
When a variance value of the first, second, and third transmission data rates is equal to or greater than the threshold value, an average value of the first, second, and third transmission data rates is calculated, and the first and second transmission data rates are calculated. 3 is higher than the average value, the first transmission data rate is lower than the third transmission data rate, and the second transmission data rate is lower than the average value. A coding rate determined based on a transmission data rate of 1, and a code determined based on the first transmission data rate for the second receiver corresponding to the second transmission data rate. The transmission apparatus according to claim 1, wherein the transmission apparatus determines to transmit moving picture data encoded at a conversion rate with frame thinning. A transmission method performed by a transmission device that transmits encoded video data to a plurality of reception devices,
A first transmission data rate that can be transmitted to the first receiving apparatus, an acquisition step of acquiring a second transmission data rate that can be transmitted to the second receiving device,
A control step of performing coding rate control and frame decimation control according to a difference between the first and second transmission data rates , wherein a value according to the difference between the first and second transmission data rates is a threshold value; for more than the value, one of the first and second transmission data rate, the receiving device before Symbol of the second corresponding to a lower second transmission data rate, a moving image data frame thinning, other The first transmission data that is higher than the first transmission data rate and the second transmission data rate is determined as a receiving device that transmits the moving image data including the intra frames that can be decoded without referring to the moving image frame. The first receiving device corresponding to the rate is transmitted to the interframe and the intratraffic that are the moving image data that is not frame-decimated and can be decoded by referring to another moving image frame. A video data rate including the inter frame and the intra frame transmitted to the first receiving device is determined as a receiving device to which the moving image data including The intra frame so that the transmission data rate does not exceed and the data rate of the intra frame transmitted to the second receiving device of the moving image data does not exceed the second transmission data rate. An encoding rate of the moving image data including an inter frame is determined, and when a value corresponding to a difference between the first and second transmission data rates is less than the threshold, the first and second transmission data rates Of these, a moving picture encoded at the determined encoding rate while determining the encoding rate based on the lower second transmission data rate Transmission method characterized by have a control step of determining to transmit over data to the first and second receiving device without frame thinning. A determination step of determining whether or not a frame rate of an intra frame constituting the frame-thinned moving image data is lower than a predetermined frame rate;
The control step performs control to increase the frame rate of the intra frame when it is determined by the determination step that the frame rate of the intra frame that constitutes the frame-thinned moving image data is lower than the predetermined frame rate. In addition, the data rate of the moving image data including the intra frame and the inter frame after the control to be transmitted that is transmitted to the first receiving device does not exceed the first transmission data rate, and the control is performed after the control. And determining the post-control encoding rate so that a data rate of the intra frame transmitted to the second receiving device does not exceed the second data rate. The transmission method according to claim 6. 8. The transmission method according to claim 6, wherein the value corresponding to the difference between the first and second transmission data rates is a variance value of the first and second transmission data rates. The acquisition step includes
A reception step of receiving a reception status notification indicating a reception status of the encoded moving image data from each of the first and second receiving devices;
9. The method according to claim 6, further comprising a calculation step of calculating the first and second transmission data rates based on reception status notifications acquired from the first and second receiving apparatuses. The transmission method according to claim 1. The acquisition step acquires a transmission data rate corresponding to the reception status of moving image data from each of the first receiving device, the second receiving device, and the third receiving device that receives moving image data from the transmitting device. ,
In the control step, the first, second, and second transmission data rates corresponding to the first, second, and third receiving apparatuses are less than the threshold value when the first, second, and third transmission data rate variance values are less than the threshold value. And a coding rate is determined based on the lowest transmission data rate among the third transmission data rates,
When a variance value of the first, second, and third transmission data rates is equal to or greater than the threshold value, an average value of the first, second, and third transmission data rates is calculated, and the first and second transmission data rates are calculated. 3 is higher than the average value, the first transmission data rate is lower than the third transmission data rate, and the second transmission data rate is lower than the average value. A coding rate determined based on a transmission data rate of 1, and a code determined based on the first transmission data rate for the second receiver corresponding to the second transmission data rate. The transmission method according to claim 6, wherein it is determined that the moving image data encoded at the encoding rate is transmitted with frame thinning. A program for causing a computer to operate as the transmission device according to any one of claims 1 to 5.

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