JP2012244566A - Receiving device, system, program and method for controlling video frame rate based on transmission bit rate - Google Patents

Abstract

The present invention provides a receiving apparatus that realizes streaming transmission with as high a subjective quality as possible according to the transmission quality of video content streaming.
An effect of deriving an influence probability according to a difference between a current transmission quality and a previous transmission quality using a transmission quality measuring means for measuring transmission quality in streaming video content and an influence probability table Using the probability deriving means, the estimated transmission bit rate calculating means for calculating the estimated transmission bit rate obtained by multiplying the current bit rate by the influence probability, and the rate correspondence table, the video frame rate corresponding to the estimated transmission bit rate is derived. And a video feedback means for feeding back related information of the video frame rate to the transmission apparatus. The transmitting device changes the frame rate of the video content to be transmitted to the receiving device to the video frame rate received from the receiving device.
[Selection] Figure 2

Description

  The present invention relates to a technique for controlling a video frame rate in transmission of video content.

  2. Description of the Related Art Conventionally, for video / audio data real-time transmission systems, there is a technique of sequentially measuring a transmission path band and changing the bit rate of the video / audio data in accordance with the transmission path band (see, for example, Patent Document 1). Specifically, according to this technique, the time interval until the data amount of the video frame accumulated in the reception buffer of the reception device reaches a predetermined threshold is observed. Based on this time interval, the bandwidth (transmission rate) is estimated. When the time interval until the amount of data reaches the predetermined threshold is short, it is determined that the transmission rate is high. On the other hand, when the time interval is long, it is determined that the transmission rate is low.

  There is also a technique for improving video quality in an unreliable transmission path by receiving a stream of video data (see, for example, Patent Document 2). According to this technique, priority is set in units of packets. Specifically, when packet loss occurs, the video quality deterioration is avoided by retransmitting a packet with higher priority (a packet important from the viewpoint of video decoding). The highest priority is set for the packet constituting the I frame of the video frame, and the second highest priority is set for the packet constituting the first P frame following the I frame.

JP 2005-159636 A Japanese Patent Laid-Open No. 2001-274861

  According to the technique described in Patent Document 1 described above, the transmission quality deterioration in the wired transmission line (Ethernet (registered trademark)) is dealt with by changing only the video / audio encoding bit rate. It was. However, it is not possible to cope with degradation of transmission quality in a wireless transmission path in which packet loss occurs frequently by changing only the coding bit rate. In particular, the deterioration of subjective video quality (image quality) due to the change of the encoding bit rate is remarkable. For video content that requires subjective quality, it is preferable to control not only the encoding bit rate but also the frame rate.

  According to the technique described in Patent Literature 2, when packet loss occurs, video quality degradation is avoided by retransmitting a packet with high priority. However, in the case of streaming transmission, when the retransmitted packet arrives at the receiving device, the reproduction time has often passed and it is considered that the expected effect cannot be achieved.

  Accordingly, an object of the present invention is to provide a receiving apparatus, system, program, and method that realize streaming transmission with the highest subjective image quality according to the transmission quality of video content streaming.

According to the present invention, in a receiving device that receives streaming video content from a transmitting device via a network,
A rate correspondence table in which video frame rates are associated with transmission bit rates;
An impact probability table that correlates the impact probability to the current transmission bit rate according to the difference between the current transmission quality and the previous transmission quality;
Transmission quality measuring means for measuring transmission quality when receiving video content from a transmission device by streaming;
An impact probability derivation means for deriving an impact probability according to the difference between the current transmission quality and the previous transmission quality using the impact probability table;
An estimated transmission bit rate calculating means for calculating an estimated transmission bit rate obtained by multiplying the current bit rate by the influence probability;
Frame rate deriving means for deriving a video frame rate corresponding to the estimated transmission bit rate using the rate correspondence table;
Video feedback means for feeding back related information of the video frame rate to the transmission device;
The transmitting apparatus functions to change the frame rate of video content to be transmitted to the receiving apparatus to the video frame rate received from the receiving apparatus.

According to another embodiment of the receiving apparatus of the present invention,
A frame type weighting factor table in which frame type weighting factors are associated with transmission quality according to I, P, and B frame types constituting video content;
It is preferable to further include a frame type weighting unit that refers to the frame type weighting coefficient table and weights the transmission quality measured by receiving the video content with a frame type weighting coefficient corresponding to the frame type constituting the video content.

According to another embodiment of the receiving apparatus of the present invention,
The receiving device includes an intra-frame position weight coefficient table in which an intra-frame position weight coefficient corresponding to transmission quality is associated according to an intra-frame position of video content;
It further includes intra-frame position weighting means for referencing the intra-frame position weighting coefficient table and weighting the transmission quality measured by receiving the video content with the intra-frame position weighting coefficient according to the intra-frame position of the video content. preferable.

According to another embodiment of the receiving apparatus of the present invention,
Transmission quality measuring means measures transmission quality in GOP (Group Of Picture) units,
It is also preferable that the difference between the current transmission quality and the previous transmission quality is calculated for each adjacent GOP.

According to another embodiment of the receiving apparatus of the present invention,
It is also preferable that the rate correspondence table is determined by MOS (Means Opinion Score) based on subjective video quality.

According to another embodiment of the receiving apparatus of the present invention,
The video feedback means, as related information of the video frame rate,
It is also preferable to feed back to the transmitting device the video frame rate itself, or the up flag / down flag for the unit rate from the current video frame rate.

According to the present invention, in a system in which a transmission device transmits video content to a reception device by streaming over a network,
The receiving device
An impact probability table that correlates the impact probability to the current transmission bit rate according to the difference between the current transmission quality and the previous transmission quality;
Transmission quality measuring means for measuring transmission quality when receiving video content from a transmission device by streaming;
An impact probability derivation means for deriving an impact probability according to the difference between the current transmission quality and the previous transmission quality using the impact probability table;
An estimated transmission bit rate calculating means for calculating an estimated transmission bit rate obtained by multiplying the current bit rate by the influence probability;
Estimated transmission bit rate feedback means for feeding back the estimated transmission bit rate to the transmission device;
The transmitter is
An estimated transmission bit rate receiving means for receiving the estimated transmission bit rate from the receiving device;
A rate correspondence table in which video frame rates are associated with transmission bit rates;
Frame rate deriving means for deriving a video frame rate corresponding to the estimated transmission bit rate received from the receiving device using the rate correspondence table;
And a frame rate changing means for changing the frame rate of the video content to be transmitted to the receiving device to the video frame rate.

According to the present invention, in a video frame rate control method in a system for transmitting video content by streaming over a network,
The receiving device
A rate correspondence table in which video frame rates are associated with transmission bit rates;
An impact probability table that correlates the impact probability with respect to the current transmission bit rate according to the difference between the current transmission quality and the previous transmission quality;
A first step of measuring transmission quality when the receiving device receives the video content from the transmitting device by streaming; and
A second step in which the receiving device derives an influence probability according to a difference between the current transmission quality and the previous transmission quality using the influence probability table;
A third step in which the receiving device calculates an estimated transmission bit rate obtained by multiplying the current bit rate by the influence probability;
A fourth step in which the receiving device derives a video frame rate corresponding to the estimated transmission bit rate using the rate correspondence table;
A fifth step in which the receiving device feeds back related information of the video frame rate to the transmitting device;
The transmission device includes a sixth step of changing the frame rate of the video content to be transmitted to the reception device to a video frame rate based on the related information received from the reception device.

According to the present invention, in a program for causing a computer mounted on a receiving device that receives video content from a transmitting device via streaming via a network to function,
A rate correspondence table in which video frame rates are associated with transmission bit rates;
An impact probability table that correlates the impact probability to the current transmission bit rate according to the difference between the current transmission quality and the previous transmission quality;
Transmission quality measuring means for measuring transmission quality when receiving video content from a transmission device by streaming;
An impact probability derivation means for deriving an impact probability according to the difference between the current transmission quality and the previous transmission quality using the impact probability table;
An estimated transmission bit rate calculating means for calculating an estimated transmission bit rate obtained by multiplying the current bit rate by the influence probability;
Frame rate deriving means for deriving a video frame rate corresponding to the estimated transmission bit rate using the rate correspondence table;
Causing the computer to function as video feedback means for feeding back video frame rate related information to the transmission device;
The transmitting apparatus functions to change the frame rate of video content to be transmitted to the receiving apparatus to the video frame rate received from the receiving apparatus.

  According to the receiving apparatus, system, program and method of the present invention, the transmission bit rate is calculated from the transmission quality of the streaming of the video content, and the video frame rate is controlled based on the transmission bit rate, so that it is as subjective as possible. Realize high-quality streaming transmission.

It is a system configuration diagram in the present invention. It is a sequence diagram between the transmitter in this invention, and a receiver. It is a block diagram of the streaming data of video content. It is explanatory drawing showing the frame classification weighting coefficient table in this invention. It is explanatory drawing showing the in-frame position weighting coefficient table in this invention. It is explanatory drawing showing the influence probability table in this invention. It is explanatory drawing of the rate corresponding | compatible table of HD resolution in this invention. It is a function block diagram of the frame rate control part of the receiver in this invention. It is a functional block diagram of the receiver in this invention. It is a function block diagram of the transmitter in this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a system configuration diagram according to the present invention.

  According to the system of FIG. 1, a mobile terminal 2 (transmission device) such as a mobile phone or a smartphone transmits video content to the video reception server 1 (reception device) via a network by streaming. In recent years, it has become possible to shoot HD (High-Definition) class video even in portable devices such as portable terminals. Such a portable terminal can transmit the captured video content to the video reception server 1 by streaming in real time. The video receiving server may be a video sharing site such as YouTube (registered trademark). In the following description, it is assumed that the transmission device is a mobile terminal and the reception device is a video reception server. Of course, conversely, the transmission device may be a video reception server, and the reception device may be a portable terminal.

  The network may be a wired network such as Ethernet (registered trademark), or may be a wireless network such as a mobile phone communication network, WiMAX (Worldwide Interoperability for Microwave Access) (registered trademark), or a wireless LAN. . In particular, in the case of a mobile terminal, the transmission quality of video content is likely to change because the network includes a wireless section. According to the present invention, even when the transmission quality of video content changes, the receiving device feeds back an optimal video frame rate to the transmitting device. By transmitting the video content changed to the video frame rate by the transmission device, streaming transmission with as high a subjective quality as possible is realized.

  Note that the video content transmitted from the transmission device is transmitted by streaming using RTP (Real-time Transport Protocol). Also, the video frame rate related information fed back from the receiving device is transmitted by RTCP (RTP Control Protocol). RTP is a data transfer protocol for delivering data streams in real time. RTCP is a protocol for controlling a data flow (transmission / reception) control session used in combination with RTP.

  FIG. 2 is a sequence diagram between the transmission apparatus and the reception apparatus in the present invention.

(S110) The mobile terminal (transmission device) 2 transmits the video content to the video reception server (reception device) 1 by streaming. Here, the video content may be training data based on a default bit rate corresponding to a wireless environment. The training data is, for example, about 50 GOP in GOP (Group Of Pictures) units. It is also preferable that the portable terminal 2 transmits training data with different bit rates as described below, depending on the wireless environment of the network.
Mobile phone network (3G): 300 kbps
WiMAX network: 1 Mbps
Wireless LAN (WiFi): 4 Mbps
Ethernet (wired): 9 Mbps

(S111) The video receiving server 1 measures transmission quality when receiving video content from the mobile terminal 2 by streaming. “Transmission quality” is, for example, delay, jitter, and packet loss rate, and is measured in units of GOP, for example. Of course, it is preferable to measure the transmission quality using video content as training data, but normal video content may also be used.

  FIG. 3 is a configuration diagram of streaming data of video content.

  According to the streaming data in FIG. 3, the streaming data includes a plurality of frames per second and is represented as a frame rate [frame per second]. According to FIG. 3, it is configured at 30 fps. A GOP unit is composed of a plurality of frames. GOP refers to a combination of several frames of a video signal, which is a unit of compression, reproduction / editing, for the MPEG system. The GOP is composed of one I (Intra) picture frame, and a plurality of P (Predictive) picture frames and B (Bidirectionally) picture frames. According to the present invention, “transmission quality” (delay, packet loss, jitter) is measured in GOP units. One frame is composed of a plurality of RTP packets.

(S112) The video receiving server 1 optionally has a “frame type weighting coefficient table” in which frame type weighting coefficients for transmission quality are associated with I, P, and B frame types constituting video content. Is also preferable.

  FIG. 4 is an explanatory diagram showing a frame type weighting coefficient table in the present invention.

  This places importance on the transmission quality in I frames with high priority. According to FIG. 4, it means that the transmission quality (delay, packet loss, jitter) of the packets constituting the I frame is considered twice as much as the transmission quality of the packets constituting the P frame and the B frame.

Then, the video receiving server (receiving device) 1 uses the frame type weighting coefficient table to weight the generated transmission quality.
For example, when a delay of 10 ms occurs in an I frame, a delay of 10 ms × 2 = 20 ms occurs.
For example, when a jitter value of 10 ms occurs in an I frame, a jitter value of 10 ms × 2 = 20 ms is generated.
For example, when one packet is lost in an I frame, two packets are lost.

(S113) Also, the video receiving server (receiving device) 1 optionally has an “intra-frame position weighting coefficient table” in which the intra-frame position weighting coefficient is associated with the transmission quality according to the intra-frame position of the video content. It is also preferable to have it.

  FIG. 5 is an explanatory diagram showing an intra-frame position weighting coefficient table in the present invention.

  This attaches importance to the transmission quality in the packet constituting the intra-frame position having a high priority. That is, the transmission quality of the packet corresponding to the center position of the screen in the frame is regarded as important. According to FIG. 5, it means that the transmission quality of the packet corresponding to the center position of the screen within the frame is considered twice as much as the transmission quality of the packet corresponding to the position of the outer frame frame within the frame.

Then, the video receiving server (receiving device) 1 weights the generated transmission quality using the intra-frame position weighting coefficient table.
For example, when a delay of 10 ms occurs in a packet corresponding to the center position of the screen, it is assumed that a delay of 10 ms × 2 = 20 ms occurs.
For example, when a jitter value of 10 ms occurs in a packet corresponding to the center position of the screen, it is assumed that a jitter value of 10 ms × 2 = 20 ms occurs.
For example, when one packet is lost in a packet corresponding to the center position of the screen, two packets are lost.

  As described above, when both FIG. 4 and FIG. 5 are considered, the transmission quality of a packet that is, for example, an I frame and configures the screen center position is a P or B frame and configures the screen outer frame position. Four times as much as the transmission quality of the packet is considered.

  As an embodiment of the present invention, it is also preferable to include a flag indicating the frame type (I, P, B) and the start / end of the frame in the extension header for each RTP packet of video streaming data. As a result, the frame type and the in-frame position can be specified only by the RTP packet.

(S114) The video receiving server (receiving device) 1 has an “influence probability table” in which the influence probabilities for the current transmission bit rate are associated with each other according to the difference between the current transmission quality and the previous transmission quality.

  FIG. 6 is an explanatory diagram showing an influence probability table in the present invention.

According to FIG. 6, an influence probability table is set for each transmission quality. The video reception server 1 uses the influence probability table to derive influence probabilities α, β, and γ according to the difference between the current transmission quality and the previous transmission quality.
[1] The delay-based influence probability α is determined according to the difference between the current delay amount Dc and the previous delay amount Dp.
[2] The influence probability β based on jitter is determined according to the difference between the current jitter Jc and the previous jitter Jp.
[3] The influence probability γ based on the packet loss rate is determined according to the difference between the current packet loss rate Lc and the previous packet loss rate Lp.

(S115) The video receiving server 1 calculates an estimated transmission bit rate obtained by multiplying the current bit rate by the influence probability.
BRn = BRc × α × β × γ
BRn: Estimated transmission bit rate
BRc: Current transmission bit rate
α: Effect probability based on delay
β: Influence probability based on jitter
γ: Impact probability based on packet loss rate

(S116) The video receiving server 1 further includes a “rate correspondence table” in which the video frame rate is associated with the transmission bit rate.

  FIG. 7 is an explanatory diagram of the HD resolution rate correspondence table in the present invention.

  In the rate correspondence table of FIG. 7, the video frame rate with respect to the transmission bit rate is set in advance. This is preferably determined by MOS (Means Opinion Score) based on subjective video quality. Thereby, the subjective video quality can be improved as much as possible according to the transmission bit rate. Note that the correspondence between the transmission bit rate and the video frame rate is preferably customized optimally. The rate correspondence table may be prepared individually according to the resolution of the video to be transmitted.

(S117) The video receiving server 1 uses the rate correspondence table to derive a video frame rate corresponding to the estimated transmission bit rate.

(S118) The video receiving server 1 feeds back the related information of the video frame rate to the mobile terminal 2. Here, there are the following two pieces of information related to the video frame rate.
・ Video frame rate itself ・ Up / down flag for the unit rate from the current video frame rate (By minimizing the amount of data, avoiding compression of the transmission band due to an increase in feedback information as a control signal)

  Thereby, the mobile terminal 2 can change the frame rate of the video content to be transmitted to the video receiving server 1.

  2, after the estimated transmission bit rate is calculated (S115), the estimated transmission bit rate may be fed back to the transmission device 2. In this case, derivation of the frame rate (S118) is executed by the transmission device 2.

  FIG. 8 is a functional configuration diagram of a video receiving server including a frame rate control unit according to the present invention.

  8 includes a communication interface 101, an IP interface 102, an RTP interface 103, an RTCP interface 104, and a frame rate control unit 11. These functional components excluding the communication interface 101 are realized by causing a computer mounted on the server to function.

  The frame rate control unit 11 includes a transmission quality measurement unit 111, a frame type weighting unit 112, a frame type weighting coefficient table 112t, an intraframe position weighting unit 113, an intraframe position weighting coefficient table 113t, and an influence probability deriving unit. 114, an influence probability table 114t, an estimated transmission bit rate calculation unit 115, a frame rate derivation unit 116, a rate correspondence table 116t, and a feedback unit 117.

  The transmission quality measuring unit 111 measures the transmission quality when receiving video content from the transmission apparatus by streaming (similar to S111 in FIG. 2). The measured transmission quality is output to the frame type weighting unit 112.

  The frame type weighting coefficient table 112t stores a frame type weighting coefficient for transmission quality associated with the I, P, B frame types constituting the video content.

  The frame type weighting unit 112 refers to the frame type weighting coefficient table 112t, and weights the transmission quality measured by receiving the video content with the frame type weighting coefficient corresponding to the frame type constituting the video content (FIG. 2). Same as S112).

  The intra-frame position weight coefficient table 113t stores an intra-frame position weight coefficient for transmission quality in association with the intra-frame position of the video content.

  The intra-frame position weighting unit 113 refers to the intra-frame position weight coefficient table 113t, and weights the transmission quality measured by receiving the video content by the intra-frame position weight coefficient corresponding to the intra-frame position of the video content (see FIG. 2 and S113).

  The influence probability table 114t stores the influence probability for the current transmission bit rate in association with the difference between the current transmission quality and the previous transmission quality.

  The influence probability deriving unit 114 uses the influence probability table to derive the influence probability according to the difference between the current transmission quality and the previous transmission quality (similar to S114 in FIG. 2).

  The estimated transmission bit rate calculation unit 115 calculates an estimated transmission bit rate obtained by multiplying the current bit rate by the influence probability (similar to S115 in FIG. 2).

  The rate correspondence table 116t stores a video frame rate with respect to a transmission bit rate.

  The frame rate deriving unit 116 derives a video frame rate corresponding to the estimated transmission bit rate using the rate correspondence table (similar to S116 in FIG. 2).

  The feedback unit 117 feeds back video frame rate related information to the transmission apparatus (similar to S117 in FIG. 2). As a result, the transmission device changes the frame rate of the video content to be transmitted to the reception device to the video frame rate received from the reception device.

  FIG. 9 is a functional configuration diagram of the receiving apparatus according to the present invention.

According to the receiving apparatus 1 of FIG. 8, the frame type and the position in the frame are determined by information from outside the frame rate control unit 11.
The frame types of I, P, and B are detected by a variable length decoding unit in the receiving device. The frame type is input to the frame rate control unit 11.
Macroblock MB (Macro Brock) arrangement information is extracted by the inverse quantization unit, and the MB arrangement information is input to the frame rate control unit 11. The frame rate control unit 11 can determine the intraframe position of the I frame from the MB arrangement information.
MB arrangement information is extracted by the intra prediction unit, and the MB arrangement information is input to the frame rate control unit 11. The frame rate control unit 11 can determine the intra-frame positions of the P and B frames from the MB arrangement information.
When the first flag / last flag of the frame is included in the RTP packet, the intra-frame position is extracted by the intra-frame position determination unit. The intra-frame position information is input to the frame rate control unit 11.

  FIG. 10 is a functional configuration diagram of the transmission apparatus according to the present invention.

  10 includes the feedback receiving unit 21 and the frame rate changing unit 22 as compared with the existing video transmitting device. The feedback receiving unit 21 receives a frame rate as feedback information from the receiving device 1 by RTCP, and outputs the frame rate to the frame rate changing unit 22. The frame rate changing unit 22 changes the frame rate of the video content to be transmitted to the frame rate received from the receiving device 1.

  Further, according to the transmission device of FIG. 10, the feedback reception unit 21 may receive the estimated transmission bit rate from the reception device 1 instead of the frame rate. In this case, the feedback receiving unit 21 includes a rate correspondence table 216t and a frame rate deriving unit 216. These functional units are exactly the same as those in the receiving apparatus 1 of FIG. A video frame rate is derived from the estimated transmission bit rate.

  As described above in detail, according to the receiving apparatus, system, program, and method of the present invention, the transmission bit rate is calculated from the transmission quality of streaming video content, and the video frame rate is calculated based on the transmission bit rate. By controlling, streaming transmission with high image quality as subjectively as possible is realized.

  Various changes, modifications, and omissions of the above-described various embodiments of the present invention can be easily made by those skilled in the art. The above description is merely an example, and is not intended to be restrictive. The invention is limited only as defined in the following claims and the equivalents thereto.

DESCRIPTION OF SYMBOLS 1 Image | video receiving server, receiver 101 Communication interface 102 IP interface 103 RTP interface 104 RTCP interface 11 Frame rate control part 111 Transmission quality measurement part 112 Frame classification weighting part 112t Frame classification weighting coefficient table 113 Intraframe position weighting part 113t Intraframe position Weight coefficient table 114 Influence probability derivation unit 114t Influence probability table 115 Estimated transmission bit rate calculation part 116 Frame rate derivation part 116t Rate correspondence table 117 Feedback part 2 Portable terminal, transmitting device 21 Feedback reception part 216 Frame rate derivation part 216t Rate correspondence table 22 Frame rate changing section

Claims (9)

In a receiving apparatus that receives video content from a transmitting apparatus via streaming via a network,
A rate correspondence table in which video frame rates are associated with transmission bit rates;
An impact probability table that correlates the impact probability to the current transmission bit rate according to the difference between the current transmission quality and the previous transmission quality;
Transmission quality measuring means for measuring transmission quality when receiving video content from a transmission device by streaming;
An influence probability deriving means for deriving the influence probability according to the difference between the current transmission quality and the previous transmission quality using the influence probability table;
Estimated transmission bit rate calculating means for calculating an estimated transmission bit rate obtained by multiplying the current bit rate by the influence probability;
Frame rate deriving means for deriving a video frame rate corresponding to the estimated transmission bit rate using the rate correspondence table;
Video feedback means for feeding back the video frame rate related information to the transmission device;
A receiving apparatus, wherein the transmitting apparatus functions to change a frame rate of video content to be transmitted to the receiving apparatus to the video frame rate received from the receiving apparatus. A frame type weighting coefficient table that associates a frame type weighting coefficient with respect to the transmission quality in accordance with the I, P, and B frame types constituting the video content;
Frame type weighting means for referring to the frame type weighting coefficient table and weighting the transmission quality measured by receiving the video content with a frame type weighting coefficient corresponding to the frame type constituting the video content. The receiving device according to claim 1. The receiving device, according to the position in the frame of the video content, an intra-frame position weight coefficient table in which an intra-frame position weight coefficient for the transmission quality is associated,
Intra-frame position weighting means for referencing the intra-frame position weighting coefficient table and weighting the transmission quality measured by receiving the video content with an intra-frame position weighting coefficient corresponding to the intra-frame position of the video content. The receiving apparatus according to claim 1, wherein the receiving apparatus is a receiver. The transmission quality measuring means measures the transmission quality in GOP (Group Of Picture) units,
The receiving apparatus according to any one of claims 1 to 3, wherein the difference between the current transmission quality and the previous transmission quality is calculated for each adjacent GOP.   The receiving apparatus according to any one of claims 1 to 4, wherein the rate correspondence table is determined by a MOS (Means Opinion Score) based on subjective video quality. The video feedback means, as related information of the video frame rate,
6. The receiving apparatus according to claim 1, wherein the video frame rate itself, or an up / down flag corresponding to a unit rate from the current video frame rate is fed back to the transmitting apparatus. . In a system in which a transmitting device transmits video content to a receiving device by streaming over a network,
The receiving device is:
An impact probability table that correlates the impact probability to the current transmission bit rate according to the difference between the current transmission quality and the previous transmission quality;
Transmission quality measuring means for measuring transmission quality when receiving video content from a transmission device by streaming;
An influence probability deriving means for deriving the influence probability according to the difference between the current transmission quality and the previous transmission quality using the influence probability table;
Estimated transmission bit rate calculating means for calculating an estimated transmission bit rate obtained by multiplying the current bit rate by the influence probability;
Estimated transmission bit rate feedback means for feeding back the estimated transmission bit rate to the transmission device;
The transmitter is
A rate correspondence table in which video frame rates are associated with transmission bit rates;
Frame rate deriving means for deriving a video frame rate corresponding to the estimated transmission bit rate received from the receiving device using the rate correspondence table;
And a frame rate changing means for changing the frame rate of the video content to be transmitted to the receiving device to the video frame rate. In a video frame rate control method in a system for transmitting video content by streaming over a network,
The receiving device
A rate correspondence table in which video frame rates are associated with transmission bit rates;
An impact probability table that correlates the impact probability with respect to the current transmission bit rate according to the difference between the current transmission quality and the previous transmission quality;
A first step of measuring transmission quality when the receiving device receives the video content from the transmitting device by streaming; and
A second step in which the receiving device derives the influence probability according to the difference between the current transmission quality and the previous transmission quality using the influence probability table;
A third step in which the receiving device calculates an estimated transmission bit rate obtained by multiplying the current bit rate by the influence probability;
A fourth step in which the receiving device derives a video frame rate corresponding to the estimated transmission bit rate using the rate correspondence table;
A fifth step in which the receiving device feeds back the related information of the video frame rate to the transmitting device;
A video frame rate control method, wherein the transmission device includes a sixth step of changing a frame rate of video content to be transmitted to the reception device to a video frame rate based on the related information received from the reception device. . In a program for causing a computer mounted on a receiving device to receive video content from a transmitting device via streaming via a network,
A rate correspondence table in which video frame rates are associated with transmission bit rates;
An impact probability table that correlates the impact probability to the current transmission bit rate according to the difference between the current transmission quality and the previous transmission quality;
Transmission quality measuring means for measuring transmission quality when receiving video content from a transmission device by streaming;
An influence probability deriving means for deriving the influence probability according to the difference between the current transmission quality and the previous transmission quality using the influence probability table;
Estimated transmission bit rate calculating means for calculating an estimated transmission bit rate obtained by multiplying the current bit rate by the influence probability;
Frame rate deriving means for deriving a video frame rate corresponding to the estimated transmission bit rate using the rate correspondence table;
Causing the computer to function as video feedback means for feeding back the related information of the video frame rate to the transmission device;
A program for a receiving apparatus, wherein the transmitting apparatus functions to change a frame rate of video content to be transmitted to the receiving apparatus to the video frame rate received from the receiving apparatus.

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