JP4358129B2 - TV conference apparatus, program, and method - Google Patents

Description

  The present invention relates to a TV conference apparatus, a program, and a method for exchanging audio data, image data, conference material data, and the like with a counterpart TV conference apparatus, for example.

  With the recent development of the Internet, the use of video conferencing systems is spreading rapidly. In the past, systems using low-speed telephone lines were common, but because of low speeds, they were not suitable for transferring moving image data, conference material data, etc., and did not spread. On the other hand, from the advantage that the Internet is relatively fast and can always be connected at a low price, a form of using a TV conference system on the Internet is becoming common.

  By the way, when a telephone line is used, once the connection is made, the line can be occupied and the available bandwidth is guaranteed. However, in the case of the Internet, it is a best effort network, and the transmission bandwidth is not guaranteed. Packet loss or the like also occurs. When data loss is not permitted, the data lost between terminals is retransmitted by using a protocol such as TCP to ensure the reliability of data transfer. However, if TCP (Transmission Control Protocol) is used to transfer media that requires real-time performance such as audio and video in a TV conference system, the delay due to data retransmission increases, so normally UDP (User Datagram Protocol) is used and missing. The resent data is not retransmitted.

  Therefore, in the video conference system using the Internet, there is no guarantee whether or not the voice data or the video data is transmitted to the other party even if it is transmitted. In addition, the user is anxious about how far the user has reached the other party, and there is a problem that the user must be inquired for confirmation.

  Therefore, in Japanese Patent Laid-Open No. 2004-120460 (Patent Document 1), quality information indicating reception quality is created at a terminal that has received audio data and moving image data, and sent to the transmission source of the audio data and moving image data. Then, by displaying the received quality information at the transmission source that has received the quality information, the user can know whether the voice data or the moving image data is transmitted to the other party. However, even if the number of packets or the like is shown to the user as quality information, it is not known how much quality the image is actually displayed, although it can be understood that the audio data and the image data have reached some extent.

  Further, in Japanese Patent Laid-Open No. 2004-186870 (Patent Document 2), a terminal that receives audio data generates audio level information, and an audio data transmitting terminal acquires the audio level information via a control server and displays audio on the screen. Display the level. The user can confirm that his / her voice is being reproduced on the other side by looking at the displayed sound level. However, with this method, it is impossible to grasp how the sound is actually reproduced on the receiving side, and only the sound is supported, and nothing is described about the moving image.

  On the other hand, there is a case where a PC (Personal Computer) screen or the like is shared between remote locations in order to share conference materials instead of voice and moving images. When sharing PC screens, unlike voice and video, TCP is used because it is necessary to deliver data to the other party sharing the data without excess or deficiency. However, the time until all of the data reaches the other party varies greatly depending on the network environment, and there is a problem that it is not known whether the data to be shared has reached the other party.

In view of this, Japanese Patent Application Laid-Open No. 7-15712 (Patent Document 3) describes a system for displaying shared data on its own device after delaying the time required for transfer to the other party. That is, in Japanese Patent Application Laid-Open No. 7-15712, the time until data transfer to the partner is predicted, the predicted time is delayed, and the shared data is displayed by displaying the shared data and the own device. Match the display timing of as much as possible. However, the situation of the network is not always constant and changes every moment, and there is a problem that it is difficult to accurately calculate the predicted time to be delayed.
Japanese Patent Laid-Open No. 2004-120460 JP 2004-186870 JP Japanese Patent Application Laid-Open No. 7-15712

  The present invention provides a TV conference device, a program, and a method capable of easily grasping how an image transmitted from the own device is actually displayed on the counterpart device.

The video conference apparatus as one aspect of the present invention is:
A video conference device that performs a video conference with the other party's video conference device via a network,
Imaging means for imaging a user;
Image encoding means for encoding user image data captured by the imaging means;
Image transmission means for packetizing and transmitting the encoded image data as the first encoded image data to the other party's video conference device;
Image decoding means for decoding the first encoded image data to generate first decoded image data;
Display means for displaying the first decoded image data;
Reception of the first encoded image data based on the number of packets that have not arrived at the other party's TV conference device and / or the number of packets that have been discarded by the other party's TV conference device. Information receiving means for receiving quality information ,
The image decoding means deletes a part of the first encoded image data according to the reception quality information, and decodes the first encoded image data after deletion.
It is characterized by that.

  A video conference apparatus according to an aspect of the present invention is a TV conference apparatus that performs a video conference with a counterpart TV conference apparatus via a network, and is shared as a conference material with the counterpart TV conference apparatus Transmitting means for transmitting shared data to the other party's TV conference device, receiving means for receiving processing status information indicating the processing status of the shared data from the other party's TV conference device, and displaying image data Display means for performing the control, and control means for outputting image data based on the shared data to the display means at a timing according to the content of the received processing status information.

The program as one aspect of the present invention is:
A program that causes a computer to function as a TV conference device that performs a TV conference with a partner's TV conference device via a network,
Image encoding means for encoding user image data captured by the imaging unit;
Image transmitting means for packetizing and transmitting the encoded image data as the first encoded image data to the other party's video conference device,
Image decoding means for decoding the first encoded image data to generate first decoded image data;
Means for outputting the first decoded image data to a display unit;
Reception of the first encoded image data based on the number of packets that have not arrived at the other party's TV conference device and / or the number of packets that have been discarded by the other party's TV conference device. Information receiving means for receiving quality information
Function the computer as
The image decoding means deletes a part of the first encoded image data according to the reception quality information, and decodes the first encoded image data after deletion.
It is characterized by that.

  A program according to an aspect of the present invention is a program that causes a computer to function as a TV conference device that performs a TV conference with a partner's TV conference device via a network. Transmitting means for transmitting shared data to be shared as conference material to the other party's TV conference device, receiving means for receiving processing status information indicating the processing status of the shared data from the other party's TV conference device, received In addition, the computer is caused to function as a control unit that outputs image data based on the shared data to a display unit at a timing according to the content of the processing status information.

The method as one aspect of the present invention includes:
A method of executing in a video conference apparatus that performs a video conference with the other party's video conference apparatus via a network,
Image the user,
Encode the captured user image data,
The encoded image data is packetized and transmitted as the first encoded image data to the other party's video conference device,
Decoding the first encoded image data to generate first decoded image data;
Displaying the first decoded image data;
Reception of the first encoded image data based on the number of packets that have not arrived at the other party's TV conference device and / or the number of packets that have been discarded by the other party's TV conference device. Receive quality information,
In the decoding of the first encoded image data, a part of the first encoded image data is deleted according to the reception quality information, and the first encoded image data after deletion is decoded. Do in,
It is characterized by that.

  According to the present invention, it is possible to easily grasp how the image transmitted by the own device is actually displayed on the counterpart device.

(First embodiment)
FIG. 2 is a diagram showing a configuration example of the video conference system according to the embodiment of the present invention.

  Two video conference apparatuses 1 and 2 in a remote place are connected via the Internet or an intranet 3. Audio data, video data, and conference material data (shared data) are transmitted and received between the TV conference apparatuses 1 and 2 via the Internet or the intranet 3.

  In FIG. 2, two video conference apparatuses are connected to each other. However, the number of the video conference apparatuses is not necessarily two, and three or more may be connected to each other. A plurality of video conference apparatuses may be connected via a server that connects multiple points such as an MCU (Multipoint Control Unit).

  FIG. 1 is a block diagram schematically showing a configuration example of a video conference apparatus.

  This video conference apparatus includes a camera 11, a display unit 12, a microphone 13, a speaker 14, a communication control unit 15, an image encoding unit 16, an image decoding unit 17, an audio encoding unit 18, an audio decoding unit 19, and a display image. A generation unit 20 is provided.

  The functions of the communication control unit 15, the image encoding unit 16, the image decoding unit 17, the audio encoding unit 18, the audio decoding unit 19, and the display image generation unit 20 are a program generated by using a normal programming technique. It may be realized by being executed by a computer such as, or may be realized by hardware.

  The camera 11 captures an image of a user who uses the video conference apparatus. A dedicated camera is used when the video conference device is a video conference device. When a personal computer (PC) is used as a TV conference device, it is conceivable to use a USB camera. Data of an image captured by the camera 11 is passed to the image encoding unit 16.

  The display unit 12 displays the input image data as an actual image. The display unit 12 may be anything as long as it can display an image, such as a CRT (Cathode Ray Tube) display or an LCD (Liquid Crystal Display).

  The microphone 13 inputs a voice of a user who uses the video conference apparatus. The voice input to the microphone 13 is passed to the voice encoding unit 18 as a voice signal. Any microphone 13 may be used as long as it can input the user's voice, such as a microphone dedicated to the video conference apparatus or a general-purpose microphone.

  The speaker 14 outputs the input audio signal as actual audio. As the speaker 14, any speaker that can generate sound from an input sound signal, such as a speaker dedicated to a TV conference device or a general-purpose speaker, may be used.

  The image encoding unit 16 encodes the image data passed from the camera 11. That is, the amount of data is too large to transfer the image data input from the camera 11 to the other party as it is. The encoding method to be used is not particularly limited. For example, JPEG compression for each frame can be considered. Alternatively, in order to increase the compression rate, MPEG2, MPEG4, H263, H264, etc. that perform compression using the similarity with the previous and subsequent frames may be used. The image encoding unit 16 passes the generated encoded data to the communication control unit 15 in order to transfer the generated encoded data to the partner video conference apparatus, and also passes it to the image decoding unit 17 for display on the own device.

  The audio encoding unit 18 encodes the audio signal passed from the microphone 13. The voice encoding unit 18 passes the encoded voice data to the communication control unit 15 in order to send it to the remote video conference apparatus.

  The communication control unit 15 transmits the encoded image data and the encoded audio data to the remote TV conference device via the Internet or the intranet 3, and also receives the encoded image data and the encoded audio data from the remote TV conference device. Receive.

  Here, in order to transfer a real-time stream such as an image or sound, packetize the data, a mechanism that reduces the quality as much as possible when the packet is discarded, a mechanism that absorbs transfer delay fluctuation for each packet, A mechanism to synchronize between image and sound is required. The communication control unit 15 realizes these functions by performing processing according to a predetermined protocol. Examples of the predetermined protocol include RTP (Realtime Transport Protocol) and RTCP (RTP Control Protocol). FIG. 3 shows a part of a protocol stack when these protocols are used.

  The audio decoding unit 19 decodes the encoded audio data received by the communication control unit 15 from the remote TV conference device. The audio decoding unit 19 passes the decoded data to the speaker 14 as an audio signal. The speaker 14 reproduces audio based on the delivered audio signal.

  The image decoding unit 17 decodes the encoded image data received by the communication control unit 15 from the remote TV conference apparatus, and decodes the encoded image data passed from the image encoding unit 16. The image decoding unit 17 passes these decoded image data to the display image generation unit 20.

  The display image generation unit 20 generates image data to be displayed on the display unit 12 using the image data transferred from the image decoding unit 17.

  For example, in the case of displaying only the image from the other party, the image data to be displayed is generated based on only the other party's image data passed from the image decoding unit 17 and passed to the display unit 12. The display unit 12 displays an image corresponding to the passed image data.

  On the other hand, when displaying the self-image together with the image from the other party, the synthesized image data is generated by synthesizing both the partner-side image data passed from the image decoding unit 17 and the self-device-side image data, The generated composite image data is transferred to the display unit 12. The display unit 12 displays a composite image based on the received composite image data. Note that the self-portrait in the displayed composite image has undergone encoding and decoding. Here, the image composition method is not particularly limited. For example, the other image may be displayed in full size, and the self-portrait may be combined to be displayed in a small size at any corner on the other image, or both images may be combined so as to have the same size. .

  As described above, according to the present embodiment, the user's own image captured by the local camera is once encoded and then further decoded and displayed on the user's device. Can be confirmed. That is, conventionally, when displaying the self-portrait, the image captured by the camera is displayed as it is without being encoded and decoded. However, in the present embodiment, the self-image is once encoded and further decoded and displayed. Therefore, it is possible to know exactly how the moving image transmitted to the counterpart device is actually displayed. Therefore, the user can participate in the TV conference with a sense of security.

(Second Embodiment)
FIG. 4 is a block diagram schematically showing a configuration example of the video conference apparatus according to the present embodiment.

  This embodiment is different from the first embodiment in that a decoded data generation unit 21 is newly added. Therefore, the following description will focus on this changed portion, and the other portions will be assigned the same reference numerals as those in FIG. 1 and will not be described in detail.

  In the first embodiment, the image encoding unit passes the encoded image data to the communication control unit and also transfers it to the image decoding unit for display on the own device. On the other hand, in the present embodiment, the image encoding unit 16 does not use the image decoding unit 17 but newly added decoded data for display on the device itself. The data is passed to the generation unit 21.

  In addition to the functions described in the first embodiment, the communication control unit 15 has a function of recognizing the reception quality of encoded image data on the reception side (partner side). The communication control unit on the reception side generates reception quality information indicating the reception quality of the encoded image data such as the ratio of reception of the encoded image data, and sends the reception quality information to the transmission source of the encoded image data. The reception quality information received at the transmission source is notified from the communication control unit 15 to the decoded data generation unit 21. An example of a protocol that can recognize the reception quality of encoded image data is RTCP.

  In RTCP, an RR packet (ReceiverReport packet) is transmitted from the encoded image data reception side to the transmission side. The RR packet stores a packet discard rate (discard rate since the previous RR packet was transmitted) and a cumulative discard packet count (number of packet discards since the start of image data reception). The packet discard rate is calculated based on a packet with a sequence number transmitted from the transmission side by RTP. Specifically, the packet discard rate can be calculated by dividing the number of packets that could not be received on the receiving side by the number of packets transmitted from the transmitting side. On the receiving side, reception quality information such as the packet discard rate and the cumulative number of discarded packets is stored in the RR packet and transmitted to the transmission source of the encoded image data.

  Here, RTP and RTCP are used to notify the reception quality of the encoded image data (packet) from the reception side to the transmission side. Other protocols may be used.

  The decoded data generation unit 21 processes the encoded image data passed from the image encoding unit 16 based on the reception quality information of the encoded image data notified from the communication control unit 15. For example, when the packet discard rate is notified as the reception quality, a part of the encoded image data is reduced according to the notified packet discard rate.

  The decoded data generation unit 21 passes the encoded image data processed based on the reception quality information to the image decoding unit 17. The decoded data generation unit 21 receives encoded image data from the other party from the communication control unit 15 and passes it to the image decoding unit 17.

  The image decoding unit 17 decodes the processed encoded image data passed from the decoded data generation unit 21 and the encoded image data from the other side, and passes them to the display image generation unit 20. The display image generation unit 20 generates image data to be displayed using the received image data after decoding, and passes the generated image data to the display unit 12. The display unit 12 displays a corresponding image based on the passed image data.

  Here, the encoded image data to be processed in the decoded data generation unit 21 is the same or as close as possible to the encoded image data that is the target for measuring the reception quality on the receiving side. And a method using the latest encoded image data obtained from the image encoding unit 16 can be considered.

  In the former case, it is necessary to buffer the encoded image data until the transmission side receives the reception quality information from the reception side, and an image with a slight delay will be displayed. It is possible to display an image closer to the displayed image.

  On the other hand, in the latter case, the image on which the reception quality information is reflected by the transmission side is different from the image to be measured on the reception side, but a large buffer is not required and the delay is small. There seems to be little discomfort.

  In the above description, the decoded data generation unit 21 directly receives the encoded image data generated by the image encoding unit 16 from the image encoding unit 16. The packetized encoded image data may be acquired from the communication control unit 21. In this way, for example, processing of encoded image data based on the packet discard rate becomes a packet discarding operation, so that the image quality that is the same as or close to that of the receiving side can be reproduced easily and more accurately.

  As described above, according to the present embodiment, the self-portrait is displayed in consideration of not only the deterioration in image quality due to the encoding of image data but also the influence of transfer on the network such as packet dropping. Therefore, it is possible to confirm an image closer to the quality of the image displayed remotely.

(Third embodiment)
FIG. 5 is a block diagram schematically showing a configuration example of the video conference apparatus according to the present embodiment.

  This embodiment is different from the first embodiment in that a use band setting unit 22 is newly added. Therefore, the following description will focus on this changed portion, and the other portions will be assigned the same reference numerals as those in FIG. 1 and will not be described in detail.

  The use band setting unit 22 sets an encoding rate (transfer rate) of image data to be transmitted to a remote TV conference device based on a user instruction.

  For example, typical transfer rate options such as 1 Mbps, 512 Kbps, 384 Kbps, and 128 Kbps are prepared, and the user selects them according to the situation. When a candidate is selected from the options, the use band setting unit 22 notifies the image encoding unit 16 of the transfer rate and that it is a candidate. When notified of the transfer rate candidate, the image encoding unit 16 encodes the input image data from the camera 11 based on the candidate transfer rate, and passes the encoded image data only to the image decoding unit 17. The image decoding unit 17 decodes the encoded image data transferred from the image encoding unit 16 and passes the decoded image data to the display image generation unit 20. The display image generation unit 20 generates preview image data based on the received decoded image data and passes it to the display unit 12. The display unit 12 displays a preview image based on the received preview image data.

  FIG. 6 shows an example of a transfer rate setting screen and a preview screen.

  The transfer rate selection menu screen 23 shows transfer rate options, and here, 512 Kbps is selected. The preview screen 24 displays a preview image that will be displayed to the other party when transferred at 512 Kbps. When the setting button 25 is pressed by the user (when an acknowledgment signal is input from the user), transmission of image data to the counterpart device is started. In other words, the image data captured by the camera 11 is encoded at 512 Kbps and transmitted. Other than this, the same processing as in the first embodiment is performed.

  That is, the image decoding unit 17 decodes the encoded image data from the image encoding unit 16 and the encoded image data from the communication control unit 15, and passes them to the display image generation unit 20. The display image generation unit 20 generates data of an image to be displayed on the display unit 12 using the received decoded image data, and passes the data to the display unit 12. The display unit 12 displays an image corresponding to the received image data.

  As described above, according to the present embodiment, since the image that would be displayed on the other party side when transmitted at the selected transfer rate is displayed on the preview screen before transmission starts, the user can transfer The transfer rate can be selected in consideration of the balance between the rate and the image quality. In addition, since the image is not transmitted to the other party before the transfer rate is determined, there is no worry that the other party displays an unsightly screen.

(Fourth embodiment)
FIG. 7 is a block diagram schematically showing a configuration example of the video conference apparatus according to the present embodiment.

  This embodiment is different from the first embodiment in that a shared data input unit 26 and a shared data control unit 27 are newly added. Therefore, in the following, this added part will be described in detail, and the other parts will be given the same reference numerals as those in FIG. 1 and will not be described in detail.

  First, the shared data will be briefly described.

  The shared data is data shared with each other in order to see the same content among the conference participants as the conference material. The shared data may be, for example, application data itself or screen data displaying the application. When the shared data is application data, in order to display the shared data, it is necessary to prepare a corresponding application on each of the shared data transmission side and reception side.

  The shared data input unit 26 takes in the shared data described above from an external device (not shown) to the TV conference device, or takes in from a data storage unit (not shown) in the TV conference device. The method for capturing is not particularly limited. For example, shared data may be acquired from another device on the network via the communication control unit 15, or shared data (screen data) may be acquired from a display connected by an RGB cable. The shared data input unit 26 passes the captured shared data to the shared data control unit 27.

  The shared data control unit 27 performs control of transmission / reception of shared data, display timing control, and the like. More details are as follows.

  The shared data control unit 27 passes the shared data passed from the shared data input unit 26 to the communication control unit 15 in order to send the shared data to the remote video conference apparatus. Further, the shared data control unit 27 generates image data (shared image data) based on the shared data in order to display the shared data even in its own device, and passes the generated shared image data to the display image generating unit 20. The display image generation unit 20 generates shared image data to be displayed (display shared image data) based on the received shared image data, and passes it to the display unit 12. Here, the shared data control unit 27 generates the shared image data. However, the shared data control unit 27 may pass the shared data to the display image generation unit 20 and the display image generation unit 20 may generate the shared image data.

  On the other hand, the display image generation unit 12 generates composite image data to be displayed based on the image data from the image decoding unit 17 and the communication control unit 15, and passes the generated composite image data to the display unit 12.

  The display unit 12 displays an image corresponding to each of the display shared image data and the composite image data received from the display image generation unit 12 on a screen prepared for each. Hereinafter, an image displayed corresponding to the display shared image data is referred to as a shared data image.

  Here, the display timing of the shared data image (the output timing of the shared image data to the display image generation unit 20 or the output timing of the display shared image data (or shared data) to the display unit 12) is a remote video conference. There are a method of displaying regardless of the display timing on the apparatus, and a method of displaying in accordance with the remote display timing as much as possible. The user may select which method to display.

  In addition, a screen for displaying the shared data image regardless of the remote TV conference device and a screen for displaying the shared data image in accordance with the display timing of the remote TV conference device may be prepared separately. In this case, the former may be displayed large, and the latter may be displayed small enough to know the display state of the other party.

  Here, an example of a method for displaying the shared data in accordance with the display timing on the remote video conference apparatus will be described.

  When the shared data control unit on the receiving side receives the shared data, the shared data control unit generates information indicating the processing status of the shared data such as the reception status and display status of the shared data and notifies the transmission source. As specific notification contents, for example, notification in a simple state such as reception completion, reception completion, display completion, and display impossibility can be considered.

  Since the time from reception completion to display completion is considered to be short in time, the transmission timing of the shared data may use the timing at which the reception completion notification is received as the display timing. Or it is good also considering the timing which received the display completion notification as a display timing more reliably. In addition, the display timing may be after a predetermined time has elapsed since the reception notification was received.

  One possible reason that the display cannot be displayed on the receiving side is that the shared data is not screen data but data of a specific application and a corresponding application is not installed on the receiving side. In such a case, the receiving side may automatically generate screen data on which the shared data is displayed and transmit it to the receiving side when receiving a notification that the display is impossible.

  As described above, according to the present embodiment, since the information indicating the processing status of the shared data is received from the shared data receiving side, the shared data is matched with the display timing on the receiving side as much as possible. Can be displayed. This eliminates the inconvenience of starting the explanation even if the meeting material has not yet been displayed to the other party in the explanation of the meeting material, etc., and eliminates the trouble of inquiring the other party whether the meeting material has been displayed. Is possible.

The block diagram which shows the structural example of the video conference apparatus according to the 1st Embodiment of this invention The block diagram which shows the structural example of the video conference system concerning embodiment of this invention Diagram showing an example of a protocol stack The block diagram which shows the structural example of the video conference apparatus according to the 2nd Embodiment of this invention. The block diagram which shows the structural example of the video conference apparatus according to the 3rd Embodiment of this invention. Diagram explaining transfer rate setting of TV conference device The block diagram which shows the structural example of the video conference apparatus according to the 4th Embodiment of this invention.

Explanation of symbols

1, 2: Video conference measure 3: Internet / Intranet 11: Camera 12: Display unit 13: Microphone 14: Speaker 15: Communication control unit 16: Image encoding unit 17: Image decoding unit 18: Audio encoding unit 19: Audio decoding unit 20: Display image generation unit 21: Decoded data generation unit 22: Use band setting unit 23: Transfer rate selection menu screen 24: Preview image 25: Setting button 26: Shared data input unit 27: Shared data control unit

Claims (13)

A video conference device that performs a video conference with the other party's video conference device via a network,
Imaging means for imaging a user;
Image encoding means for encoding user image data captured by the imaging means;
Image transmission means for packetizing and transmitting the encoded image data as the first encoded image data to the other party's video conference device;
Image decoding means for decoding the first encoded image data to generate first decoded image data;
Display means for displaying the first decoded image data;
Reception of the first encoded image data based on the number of packets that have not arrived at the other party's TV conference device and / or the number of packets that have been discarded by the other party's TV conference device. Information receiving means for receiving quality information ,
The image decoding means deletes a part of the first encoded image data according to the reception quality information, and decodes the first encoded image data after deletion.
A video conference apparatus characterized by that. 2. The video conference apparatus according to claim 1 , wherein a transmission / reception protocol of the reception quality information is RTCP (RTP (Realtime Transport Protocol) Control Protocol). A coding rate setting means for selecting a coding rate of the image data from a plurality of coding rates;
The image encoding means encodes the image data at the selected encoding rate;
The video conference apparatus according to claim 1 . The image transmission means waits for transmission of the first encoded image data until an acknowledgment signal indicating acceptance of the selected encoding rate is input.
The video conference apparatus according to claim 3 . Shared data transmitting means for transmitting shared data to be shared as conference material with the other party's TV conference device to the other party's TV conference device;
Processing status information receiving means for receiving processing status information indicating the processing status of the shared data from the other party's TV conference device;
Control means for outputting image data based on the shared data to the display means at a timing according to the content of the received processing status information;
The video conference apparatus according to claim 1 , further comprising: The processing status information includes a reception completion notification indicating that reception of the shared data has been completed by the counterpart TV conference device, or image data based on the shared data received by the counterpart TV conference device. Including a display completion notification indicating that it has been displayed on the TV conference device,
When the control unit detects that the processing status information is received by the processing status information receiving unit, the control unit outputs image data based on the shared data to the display unit.
The video conference apparatus according to claim 5 . A program that causes a computer to function as a TV conference device that performs a TV conference with a partner's TV conference device via a network,
Image encoding means for encoding user image data captured by the imaging unit;
Image transmitting means for packetizing and transmitting the encoded image data as the first encoded image data to the other party's video conference device,
Image decoding means for decoding the first encoded image data to generate first decoded image data;
Means for outputting the first decoded image data to a display unit;
Reception of the first encoded image data based on the number of packets that have not arrived at the other party's TV conference device and / or the number of packets that have been discarded by the other party's TV conference device. Information receiving means for receiving quality information
Function the computer as
The image decoding means deletes a part of the first encoded image data according to the reception quality information, and decodes the first encoded image data after deletion.
A program characterized by that. 8. The program according to claim 7 , wherein a transmission / reception protocol of the reception quality information is RTCP (RTP (Realtime Transport Protocol) Control Protocol). Causing the computer to further function as a coding rate setting means for selecting a coding rate of the image data from a plurality of coding rates;
The image encoding means encodes the image data at the selected encoding rate;
The program according to claim 7 . The image transmission means waits for transmission of the first encoded image data until an acknowledgment signal indicating acceptance of the selected encoding rate is input.
The program according to claim 9 . Shared data transmitting means for transmitting shared data to be shared as conference material with the other party's TV conference device to the other party's TV conference device;
Processing status information receiving means for receiving processing status information indicating the processing status of the shared data from the other party's TV conference device;
Control means for outputting image data based on the shared data to the display unit at a timing according to the content of the received processing status information;
The program according to claim 7 , further causing the computer to function as: The processing status information includes a reception completion notification indicating that reception of the shared data has been completed by the counterpart TV conference device, or image data based on the shared data received by the counterpart TV conference device. Including a display completion notification indicating that it has been displayed on the TV conference device,
The control unit, when detecting that the processing status information is received by the processing status information receiving unit, outputs image data based on the shared data to the display unit.
The program according to claim 11 . A method of executing in a video conference apparatus that performs a video conference with the other party's video conference apparatus via a network,
Image the user,
Encode the captured user image data,
The encoded image data is packetized and transmitted as the first encoded image data to the other party's video conference device,
Decoding the first encoded image data to generate first decoded image data;
Displaying the first decoded image data;
Reception of the first encoded image data based on the number of packets that have not arrived at the other party's TV conference device and / or the number of packets that have been discarded by the other party's TV conference device. Receive quality information,
In the decoding of the first encoded image data, a part of the first encoded image data is deleted according to the reception quality information, and the first encoded image data after deletion is decoded. Do in,
A method characterized by that.

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