JP2007281716A - Wireless moving picture transmission system, wireless moving picture transmission method, wireless moving picture transmission apparatus, wireless moving picture transmission method, and computer program thereof, wireless moving picture receiving apparatus, wireless moving picture receiving method, and computer program thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology of achieving wireless moving picture transmission without increasing a video delay and causing interruption to a moving picture in the case of transmitting the moving picture through a wireless link. <P>SOLUTION: When a transmission side transmits moving picture data by using wireless communication, the transmission side divides frame images of the moving picture data into a plurality of division images depending on a communication environment of wireless intervals, attaches header information including image positional information and size information to each division image and transmits each division image in a prescribed order. A receiving side receives each division image transmitted from the transmission side, uses each received division image in the transmission order, and references the image positional information and the size information by each division image to reconfigure the frame images. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wireless moving image transmission system, a wireless moving image transmission method, a wireless moving image transmission device, a wireless moving image transmission method, and the like suitable for transmitting moving image data between, for example, a tuner and a display device using wireless communication. The present invention relates to a computer program, a wireless moving image receiving apparatus, a wireless moving image receiving method, and the computer program.

  When a flat-screen television such as a liquid crystal television receiver or a plasma television receiver is used as a so-called wall-mounted television, the appearance is impaired if an antenna cable extends from the display device. Therefore, it is possible to reduce the number of antenna cables connected to the display device by separating the tuner from the display device and connecting the tuners wirelessly.

  However, when video transmission is performed by connecting the tuner and the display device with a wireless link, the video will be interrupted unless durability against random errors in the wireless section is given, and the video will not be displayed correctly, causing discomfort during viewing. The problem of increasing is caused. In order to avoid this problem, the display device has a reception buffer unit with a sufficient capacity in the past, and if a random error such as burst noise occurs in the wireless section, a video is created from the data buffered in the reception buffer unit. A method is adopted in which the buffer amount is recovered by retransmitting the moving image from the tuner to the display device during the playback.

  An image communication apparatus that includes a storage unit that stores division patterns and priorities in association with each other, and that divides and transmits one image into a plurality of images based on predetermined pattern information corresponding to the selected priority. It has been proposed (see Patent Document 1).

JP 2005-57494 A

  However, the above-described method has a problem that the video delay increases as the buffer amount in the reception buffer unit increases. In other words, the real-time nature of the video is greatly impaired, the response speed of the display device decreases when operated using a remote controller, and the input from the controller is on the screen when using a game machine connected to the display device. The problem of not synchronizing with the movement of the camera arises. In addition, as a matter of course when the buffer amount is reduced, there is a problem that the moving image is interrupted due to a random error in the wireless section.

  The present invention has been made in view of such a point, and an object of the present invention is to realize wireless moving image transmission in which moving images are not interrupted without increasing a video delay when moving images are transmitted using wireless communication. To do.

  In order to solve the above problems, according to a first aspect of the present invention, in a wireless moving image transmission system that transmits moving image data using wireless communication, a plurality of frame images of the moving image data are converted according to a communication environment in a wireless section. A wireless moving image transmitting apparatus that divides the image into divided screens, adds header information including screen position information and size information for each divided screen, and transmits the divided screens in a predetermined order; and the wireless moving image transmitting apparatus that is sent from the wireless moving image transmitting apparatus From the wireless video receiver that receives each divided screen, uses the received divided screens in the predetermined order, and reconstructs the frame image with reference to the screen position information and size information for each divided screen It is characterized by comprising.

  According to the above configuration, by dividing the frame image of the moving image data into a plurality of divided images according to the communication environment of the wireless section, for example, whether it is good or bad, the divided image is enlarged when the communication environment is good, and the communication environment is If it is bad, the divided image can be made smaller and transmitted.

  A second aspect of the present invention is that, in the first aspect, an error rate measured at a data transmission destination is used as data serving as an index for determining the communication environment in the wireless section. The wireless moving image transmission apparatus includes a screen division number determination unit that determines the number of divisions of the frame image according to error rate information transmitted from a communication destination, and reduces the number of divisions when the error rate is high, and the error rate is When the number is low, the number of divisions is increased, and the frame image is divided according to the number of divisions determined by the screen division number determination unit. Alternatively, instead of the error rate, the number of divisions of the frame image is determined by the S / N ratio.

  According to the above configuration, since the communication environment is determined using the error rate or S / N ratio information sent from the transmission destination, the state of the communication environment can be accurately determined, and according to the state of the communication environment The number of screen divisions can be set dynamically.

  Further, a third aspect of the present invention includes a priority determination unit that determines the priority of each divided screen based on the correlation in the divided screen at the same position of the current frame and the previous frame in the first aspect. The divided screens are transmitted in descending order of priority determined by the priority determination unit.

  According to the above configuration, since the priority of divided images with low correlation (many movements) is set high and transmitted preferentially, divided images that cannot be transmitted within a certain period of time are divided screens with high correlation (low movement). It can be.

  In addition, according to a fourth aspect of the present invention, in the third aspect, the priority determination unit responds to screen position information of the divided screen when there are divided screens having the same priority based on the correlation. And setting the priority.

  According to the above configuration, by appropriately setting the screen position information of the split screen that is transmitted with priority, it is possible to transmit from the split screen that is located in a conspicuous place.

  According to a fifth aspect of the present invention, in the first aspect, the wireless moving image receiving apparatus includes a storage unit that temporarily stores moving image data of the previous frame, and all divided screens within a set time of one frame. In the case where the received image cannot be received, a divided screen at the same position of the previous frame stored in the storage unit is used instead of the divided screen that could not be received.

  According to the above configuration, the low-priority split screen resulting in a transmission error is displayed without interruption by reconstructing the frame using the split screen of the previous frame, and the effects of random errors are human. Make it harder to recognize.

  According to the present invention, even when moving image transmission is performed using wireless communication, the moving image can be displayed on the receiving side without increasing the video delay and without interrupting the moving image. Therefore, chip cost is reduced by significantly reducing the receive buffer that is generally used for the purpose of not interrupting the video, and the response speed when operating a remote controller or game machine is reduced by reducing the video delay. Can do.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

  A configuration example of the wireless moving image transmission system of the present invention is shown in FIG. The wireless moving image transmission system in this embodiment includes a tuner 1 and a display device 20. The tuner 1 and the display device 20 are examples of a wireless moving image transmitting device and a wireless moving image receiving device, respectively. The tuner 1 and the display device 20 are independent of each other, and are connected so as to be able to transmit / receive data to / from each other by wireless communication. The modulation / demodulation method for wireless communication is not particularly limited, but a large-capacity transmission method such as UWB (Ultra Wide Band) is desirable for transmitting moving image data.

  The tuner 1 demodulates a broadcast wave such as BS / CS / terrestrial wave received via an external antenna to extract a baseband signal, and the baseband signal of the broadcast wave demodulated by the front end unit 2 A screen dividing unit 3 that divides a formed image, a priority determining unit 4 that adds a priority based on a predetermined standard to each divided screen after the screen division, and compresses the image data subjected to the division processing An image compression unit 5, a transmission buffer unit 6 that temporarily stores (buffers) compressed data, a wireless transmission unit 7 that transmits data buffered in the transmission buffer unit 6 by wireless communication, and transmission and reception An antenna switch unit 8 for switching the antenna is provided.

  In addition, a frame memory (storage unit) 9 that stores previous frame information to be referred to when priority is determined by the priority determination unit 4 and a radio reception that receives a command transmitted from the display device 20 via the antenna switch unit 8. Unit 10, transmission rate control unit 11 that controls the transmission rate according to the degree of data in transmission buffer unit 6 and / or a command received from radio reception unit 10, and the transmission rate controlled by transmission rate control unit 11 A screen division number determination unit 12 that determines an optimal number of screen divisions according to the communication environment of the wireless section and a timing control unit 13 that transmits a clock to control the operation timing of each unit are provided.

  The display device 20 includes an antenna switch unit 21 that switches antennas between reception and transmission, a wireless reception unit 22 that receives data transmitted from the tuner 1 through wireless communication via the antenna switch 21, and buffers the received data. Reception buffer unit 23, image decompression unit 24 for decompressing data in reception buffer unit 23, screen reconstruction unit 25 for reconstructing an image from the decompressed data, and display (display surface) 27 for the reconstructed image A display driver 26 is provided for display.

  Furthermore, a frame memory (storage unit) 28 that stores information of a previous frame necessary for reconstructing an image, a command transmission unit 29 that measures an error rate from data received by wireless communication, and transmits a command, The wireless transmission part 30 which transmits a command to the tuner 1 via the antenna switch part 21 and the timing control part 31 which controls the operation timing of these each part are provided.

  The operation of the tuner 1 when performing moving image transmission by wireless communication is shown in the flowchart of FIG. First, when the tuner 1 receives a broadcast wave from the external antenna, the front-end unit 2 demodulates the received broadcast wave, and outputs the demodulated broadcast wave (moving image data) to the screen dividing unit 3 (step S1). The screen dividing unit 3 divides the image for one frame based on the demodulated broadcast wave baseband signal into a plurality of divided screens (blocks) according to the communication environment of the wireless section (step S2). Then, header information including “screen position information” and “size information” in the pre-division screen (one-frame screen) of the divided screen is added to each divided screen, and output to the priority determination unit 4. Further, it is preferable to add a “frame number” that can identify which frame the divided image is for.

  FIG. 3 is a diagram for explaining screen position information and size information added to the divided screen. For example, the upper left corner of the screen 40 before the division is the origin (0, 0), the screen position information of the arbitrary divided screen 41 is represented by coordinates (X, Y), and the size information is represented by “W” and “H”. Yes. This screen position information is used to specify a block position in a frame corresponding to the data when data is received on the display device 20 side.

  The screen division process in step S2 is executed based on the number of divisions determined by the process shown in FIG. Hereinafter, the screen division number determination process will be described with reference to the flowchart of FIG.

  In FIG. 4, the error rate in a normal communication environment is first measured in advance from the data received by the wireless reception unit 22 by the command transmission unit 29 of the display device 20. Next, the error rate in the current communication environment is measured. Then, the command including these error rate information is transmitted from the command transmission unit 29 to the tuner 1 via the wireless transmission unit 30 and the antenna switch unit 21. In the tuner 1, the command transmitted from the display device 20 is received by the wireless reception unit 10 via the antenna switch unit 8, and the received command is supplied to the transmission rate control unit 11. Then, the transmission rate control unit 11 compares the normal error rate with the current error rate, and determines whether or not the current error rate has increased from the normal time (step S11).

  In the determination process of step S11, when the transmission rate control unit 11 determines that the error rate has increased, the transmission rate control unit 11 determines to increase the number of divisions (step S12). Then, the transmission rate is lowered based on the determination, and the changed transmission rate is output to the screen division number determination unit 12. On the other hand, if it is determined that the error rate has not increased, the process proceeds to step S13.

  Next, the transmission rate control unit 11 compares the normal error rate with the current error rate, and determines whether or not the current error rate has decreased from the normal time (step S13).

  In the determination process of step S13, when the transmission rate control unit 11 determines that the error rate has decreased, the transmission rate control unit 11 determines to decrease the number of divisions (step S14). Then, the transmission rate is increased based on the determination, and the changed transmission rate is output to the screen division number determination unit 12. On the other hand, if it is determined that the error rate has not decreased, the process proceeds to step S15 to determine to maintain the current number of divisions (step S15).

  Then, the screen division number determination unit 12 determines the number of image divisions for one frame based on the transmission rate supplied from the transmission rate control unit 11.

  As described above, in this example, the number of screen divisions is dynamically changed according to the error rate of the wireless section, and in a communication environment with a high error rate (a lot of errors), the number of screen divisions is increased and the error rate is increased. Reduce the number of screen divisions in a low (low error) communication environment. The number of screen divisions (size) can be set in a range from one pixel to the entire screen (no division).

  For example, in the example of FIG. 5, the original screen, that is, one screen is usually divided into 48 with the same size of each divided screen. However, as the error rate increases, one screen is changed to 192 divisions. When the error rate is low, one screen is changed to 12 divisions. It is not always necessary to divide the screen into the same size (vertical x horizontal). For example, it may be set as appropriate, for example, by reducing the size of the divided screen at a position where the error rate is high. Further, the number of divisions changed according to the error rate is not limited to 192 or 12 mentioned in this example. For example, when it is desired to faithfully follow the number of divisions in response to changes in the communication environment, the number of divisions is not limited. Many may be set.

  In the flowchart of FIG. 4, the number of divisions is changed by determining the increase or decrease of the error rate from the normal communication environment. However, the error rate is set in three ranges in advance, and the detected current error rate is The number of divisions may be determined depending on which range is included.

  Further, the command transmission unit 29 measures the error rate as data serving as an index for determining the quality of the communication environment in the wireless section. Instead of the error rate, the signal level of the current received data is not input. The S / N ratio expressed with respect to the noise level in the case may be measured, and the number of divisions may be determined using this S / N ratio. For example, when the S / N ratio is small, the number of divisions is increased, and when the S / N ratio is large, the number of divisions is decreased.

  Returning to the description of the operation of the tuner 1 shown in the flowchart of FIG. After completing the one-frame screen dividing process in step S2, the priority determining unit 4 determines the priority for each divided screen (block) (step S3). Then, the divided screens are output to the image compression unit 5 in descending order of priority.

  Here, FIG. 6 shows a flowchart of a method for setting the transmission priority after screen division executed in the process of step S3 of FIG. In order to set the transmission priority, the priority determination unit 4 first reads the divided screen at the same position of the previous frame stored in the frame memory 9 and correlates the divided screens at the same position of the previous frame and the current frame. Is measured (step S21). The measurement of correlation is a well-known technique. For example, the brightness, hue, saturation, etc. of each pixel constituting a divided screen are expressed numerically and expressed in gradation, and the same in the previous and subsequent frames based on these numerical information. Measure by comparing split screens.

  Then, the correlation values of the divided screens are rearranged in descending order (step S22), and the priority is determined (step S23). That is, the priority is set higher in the order of the correlation value of each divided screen having the lowest (larger motion). In this case, the higher priority is set for the part with more motion, and the priority is set for the split screen with less motion, so if a random error occurs, the screen that was not correctly sent / received even if retransmission was not in time There is an advantage that a screen with less movement is obtained, and even if the screen of the previous frame is used on the display device 20 side, there is little discomfort.

  Furthermore, as another example, a priority setting method that considers the correlation information between the screen position information of the divided screen and the previous frame is also conceivable. For example, human eyes tend to focus on the center rather than the edge of the screen, so a method for determining the priority using this may be considered. For example, when there are divided screens having the same correlation value, the priority of the divided screen at the center of the screen is set higher. In this way, for the divided screens having the same correlation value, the divided screen located at the center is preferentially transmitted, so that the influence of the random error is less likely to be recognized by human eyes on the screen after the reconstruction. Furthermore, it is conceivable to set the priority of divided screens having the same correlation value according to a predetermined pattern.

  Next, the image compression unit 5 compresses the data of each divided screen in the priority order added by the priority determination unit 4 (step S4). If there are multiple screens with the same priority, they are compressed in random order. As a compression method, for example, compression such as a line-based compression format as well as a frame-based compression format such as JPEG (Joint Photographic Expert Group) 2000 method and MPEG (Moving Picture Experts Group) method are conceivable, but there is a particular limitation. do not do. Note that the data compression processing by the image compression unit 5 is not necessarily required depending on communication conditions, for example, the wireless section has a wide band.

  The image compression unit 5 inputs the compressed divided screen data to the transmission buffer unit 6 (step S4). The transmission buffer unit 6 stores the compressed divided screen data for a certain period of time, and then outputs it to the wireless transmission unit 7 (step S5).

  The wireless transmission unit 7 modulates the data of the compressed divided screen, packetizes the modulated compressed divided screen data, and transmits the packetized data to the display device 20 via the antenna switch unit 8. As a matter of course, the interframe synchronization between the wireless transmission unit 7 of the tuner 1 and the wireless reception unit 10 of the display device 20 is assumed to be performed by a known appropriate method.

  In this example, the time for which the compressed divided screen data stored in the transmission buffer unit 6 is stored in the transmission buffer unit 6 is a fixed time (for example, 1/2 frame (1/120 when the frame period is 1/60 seconds) Sec))). This fixed time may be within one frame time. The wireless transmission unit 7 determines whether or not a predetermined time has elapsed since the data of the compressed divided screen was stored (step S6). If the predetermined time has not elapsed, the transmission of the compressed divided screen data stored in the wireless transmission unit 7 is continued (step S7). When the predetermined time has elapsed, the compressed divided screen data remaining in the wireless transmission unit 7 is deleted (step S8).

  In this way, packets that remain without being transmitted to the wireless transmission unit 7 for a certain period of time are flushed (erased) and are not retransmitted. If a packet that has not been transmitted for a certain period of time exists in the wireless transmission unit 7, the transmission rate control unit 11 performs a process of decreasing the transmission rate in accordance with the flushed packet amount. Therefore, a packet that has not been transmitted for a certain period of time is flushed, the next packet is transmitted, and the transmission rate is appropriately controlled, so that it is possible to achieve wireless video transmission without increasing video delay and without video interruption. become. At this time, the number of divisions may be increased or decreased by the screen division number determination unit 12 based on the changed transmission rate.

  Next, the operation of the display device 20 will be described with reference to the flowchart of FIG. The packet of the compressed divided screen data transmitted from the tuner 1 is received by the wireless reception unit 22 via the antenna switch 21 (step S31). The wireless reception unit 22 outputs the correctly received packet to the reception buffer unit 23. The reception buffer unit 23 stores the packet supplied from the wireless reception unit 22 until one frame time elapses (step S32). After the elapse of one frame time, the packet stored in the reception buffer unit 23 is supplied to the image decompression unit 24, and the image decompression unit 24 decompresses the data of the divided screen input for one frame time (step S33). . The decompressed data is input to the screen reconstruction unit 25 and the frame memory 28.

  Then, the screen reconstruction unit 25 reconstructs the frame screen from the divided screen based on the screen position information added to the packet. At this time, it is determined whether or not all the data of the divided screens constituting the frame screen are normally received within one frame time (step S34). When all the data is received normally, the frame screen is reconstructed with the received data (step S35).

  Further, in the determination process of step S34, if there is data that could not be received normally, the process proceeds to step S37. A divided screen in which transmission / reception has not been performed correctly due to a random error in the wireless section is constructed using the screen of the same portion of the previous frame stored in the frame memory 28 (step S36).

  The screen reconstruction unit 25 stores the frame screen constructed by the processing of step S36 and step S37 in the frame memory 28 so that it can be used when the next frame is reconstructed (step 37).

  Then, the reconstructed frame screen is transmitted to the display driver 26. The display driver 26 includes a memory such as a VRAM (Video Random Access Memory), for example. The display driver 26 stores images in units of frames and sequentially outputs frame images to a display (display unit) 27 such as a liquid crystal panel to display a moving image ( Step S38).

  When the reconstructed screen is displayed on the display 27, if there is a divided screen in which transmission / reception has not been performed correctly due to a random error in the wireless section, the screen of the previous frame is temporarily displayed in a certain divided portion of the screen. However, since the divided portion is a place that is difficult for human eyes to recognize (a divided screen with low priority), it is possible to reduce discomfort.

  Also, change the number of divisions according to the error rate of the radio section, that is, dynamically control to increase the number of divisions in a communication environment with a high error rate (high error) and reduce the number of divisions in a communication environment with a low error rate. Thus, by setting a finer priority and making a divided screen that cannot be transmitted in the frame time a screen having a high correlation as much as possible (a screen with less movement), it is possible to further deceive human eyes.

In the embodiment described above, in contrast to the conventional approach of increasing the reception buffer so that the moving image is not interrupted in the middle, the data that can be reliably transmitted and received within a certain time is largely changed from the previous frame. It is supposed to send. For this reason, it becomes possible to prevent the occurrence of the following situation.
First, in the case of real-time data transmission such as streaming, a time that can be allocated to transmission of one frame is determined. For example, in the case of NTSC, since it is about 30 frames / second, the number of hours required for transmission / reception per frame is inevitably determined when real-time display is performed. In this case, if it occurs that all the data corresponding to one frame cannot be transmitted / received within the time, the data received after the time will be lost when the frame is displayed.
According to the system according to the present embodiment, since there is no change from the previous frame or a small portion is postponed, even if reception of data corresponding to one frame is not completed If inter-frame interpolation is performed using the data of the previous frame, it is possible to minimize image quality degradation that occurs in the frame.
Therefore, data that is conspicuous to the human eye (with a large change from the previous frame) is transmitted preferentially, and low-priority data that results in a transmission error may be lost even if it is lost. By reconstructing a frame using data, it is possible to make it difficult for human eyes to recognize the effects of random errors.

  Also, the reception buffer time on the display device side is set to a certain time, for example, one frame time, and data that has not been transmitted / received within the certain time can be automatically made into a divided image at an inconspicuous portion of the screen. There is no need to increase the number of buffers, in other words, the amount of reception buffer can be reduced, and the video delay is not increased.

  In addition, the same priority data is automatically sent from the inconspicuous part of the screen so that the effects of random errors are less visible to the human eye on the reconstructed screen. Can be.

  As described above, according to the present embodiment, it is possible to construct a wireless moving image transmission system in which moving images are not interrupted without increasing the video delay even when moving images are transmitted using wireless communication.

  In addition, since the display device does not require a large reception buffer, chip costs can be reduced by significantly reducing the reception buffer, and when operating a remote controller or game machine by reducing video delay The reaction rate of can be improved.

  The present invention is not limited to the above-described embodiments. For example, an image reproducing device such as a DVD player instead of the tuner 1 as a wireless moving image transmitting device, a projector as a wireless moving image receiving device instead of the display device 20, and the like. It goes without saying that various modifications and changes can be made without departing from the scope of the present invention, such as application of the display device. In this case, for example, an image reproduced by a DVD player can be transmitted by wireless communication to a projector installed on the ceiling of a room and the image received on the projector side can be comfortably reproduced. Since the DVD player and the projector are connected wirelessly, there is no cable and the room is clean.

  Further, the wireless moving image transmission process (see FIG. 2) by the wireless moving image transmission apparatus can be executed by hardware, but can also be executed by software. When a series of processing is executed by software, program code constituting the software is stored in a storage unit (not shown) such as a ROM built in a microcomputer (not shown), for example, and the microcomputer reads the program from the ROM. This can be realized by reading the code, expanding it in the RAM, and executing predetermined processing and control on the data to be transmitted. The same applies to the wireless moving image receiving apparatus.

  In addition, the present invention supplies a recording medium storing software program codes for realizing the functions of the above-described exemplary embodiments to a wireless moving image transmitting apparatus or a wireless moving image receiving apparatus, and a computer (arithmetic processing apparatus) of the apparatus supplies the recording medium. Needless to say, this can also be achieved by reading and executing the program code stored in the recording medium.

  As a recording medium for supplying the program code in this case, for example, a floppy disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a DVD, a magnetic tape, a nonvolatile memory card, a ROM, etc. Can be used.

  Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an OS (Operating System) running on the computer based on the instruction of the program code. Includes a case where the function of the example of the above-described embodiment is realized by performing part or all of the actual processing.

It is a block diagram which shows the structural example of the wireless moving image transmission system which concerns on one Embodiment of this invention. It is a flowchart which shows the process by the tuner (wireless moving image transmission apparatus) which concerns on one Embodiment of this invention. It is a figure where it uses for description of the screen position information and magnitude | size information of a divided screen which concern on one Embodiment of this invention. It is a flowchart which shows the screen division number determination process which concerns on one Embodiment of this invention. It is a figure which shows the example of a screen division concerning one Embodiment of this invention. It is a flowchart which shows the split screen priority determination process which concerns on one Embodiment of this invention. It is a flowchart which shows the process by the display apparatus (wireless moving image receiver) which concerns on one Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Tuner, 3 ... Screen division part, 4 ... Priority determination part, 6 ... Transmission buffer part, 7 ... Wireless transmission part, 9 ... Frame memory, 10 ... Wireless reception part, 11 ... Transmission rate control part, 12 ... Screen Division number determination unit, 20 ... display device, 22 ... wireless reception unit, 23 ... reception buffer unit, 25 ... screen reconstruction unit, 26 ... display driver, 27 ... display, 28 ... frame memory, 29 ... command transmission unit, 30 ... wireless transmission unit, 40 ... screen, 41 ... split screen

Claims (14)

In a wireless video transmission system that transmits video data using wireless communication,
The frame image of the moving image data is divided into a plurality of divided screens according to the communication environment of the wireless section, and header information including screen position information and size information is added to each divided screen, and each divided screen is followed in a predetermined order A wireless video transmission device for transmission;
Receiving each of the divided screens sent from the wireless video transmitting device, using each of the received divided screens in the predetermined order, referring to the screen position information and size information for each divided screen, the frame image A wireless video receiver to be reconstructed;
A wireless moving image transmission system comprising: In a wireless moving image transmission method for transmitting moving image data using wireless communication between a wireless moving image transmitting device and a wireless moving image receiving device,
A step of dividing a frame image of the moving image data into a plurality of divided screens according to a communication environment in a wireless section;
Adding header information including screen position information and size information for each divided screen and transmitting each divided screen according to a predetermined order;
Receiving each of the divided screens transmitted from the wireless moving image transmitting device at the wireless moving image receiving device;
Using each received divided screen in the predetermined order, reconstructing the frame image with reference to the screen position information and size information for each divided screen;
A wireless moving picture transmission method comprising: In a wireless video transmission device that transmits video data using wireless communication,
A screen dividing unit that divides the frame image of the moving image data into a plurality of divided screens according to a communication environment of a wireless section;
A wireless transmission unit that adds header information including screen position information and size information for each divided screen and transmits each divided screen according to a predetermined order;
A wireless moving image transmitting apparatus comprising: A screen division number determining unit that determines the number of divisions of the frame image according to error rate information sent from a communication destination;
The screen division number determination unit increases the number of divisions when the error rate is high, and reduces the number of divisions when the error rate is low,
The screen dividing unit divides the frame image according to the number of divisions determined by the screen division number determining unit.
The wireless moving image transmitting apparatus according to claim 3. In place of the error rate, the number of divisions of the frame image is determined by the S / N ratio.
The wireless moving image transmitting apparatus according to claim 4. A priority determining unit that determines the priority of each divided screen based on the correlation in the divided screen at the same position of the current frame and the previous frame;
The wireless transmission unit transmits the divided screens in descending order of priority determined by the priority determination unit.
The wireless moving image transmitting apparatus according to claim 3. The priority determination unit sets the priority according to the screen position information of the divided screen when there are divided screens having the same priority based on the correlation.
The wireless moving image transmitting apparatus according to claim 6. In a wireless video transmission method for transmitting video data using wireless communication,
Dividing the frame image of the moving image data into a plurality of divided screens according to a communication environment of a wireless section;
Adding header information including screen position information and size information for each divided screen and transmitting each divided screen according to a predetermined order;
A wireless moving image transmission method comprising: A computer program for transmitting moving image data using wireless communication,
A process of dividing the frame image of the moving image data into a plurality of divided screens according to the communication environment of the wireless section;
A process of adding header information including screen position information and size information for each divided screen and transmitting each divided screen according to a predetermined order;
A computer program that causes a computer to execute. In a wireless moving image receiving apparatus that receives moving image data in which a frame image is divided into a plurality of divided screens from a communication destination via wireless communication,
A wireless receiver that receives each divided screen sent in a predetermined order from the communication destination;
A screen that uses the divided screens received by the wireless reception unit in the predetermined order and reconstructs the frame image with reference to header information including screen position information and size information added to each divided screen. The reconstruction department,
A wireless moving image receiving apparatus comprising: A storage unit for temporarily storing the moving image data of the previous frame;
If all the split screens cannot be received within the set time of one frame, the screen reconstruction unit splits the same frame in the previous frame stored in the storage unit in place of the split screen that could not be received. Using the screen,
The wireless moving image receiving apparatus according to claim 10. A command transmission unit that measures data serving as an index for determining a communication environment of a wireless section from received data, and transmits a command including a measurement result to the communication destination,
The wireless moving image receiver according to claim 10, comprising: In a wireless moving image receiving method for receiving moving image data in which a frame image is divided into a plurality of divided screens from a communication destination via wireless communication,
Receiving each divided screen sent in a predetermined order from the communication destination;
Using the received divided screens in the predetermined order, reconstructing the frame image with reference to header information including screen position information and size information added to each divided screen;
A wireless moving image receiving method comprising: A computer program for receiving, via wireless communication, moving image data obtained by dividing a frame image into a plurality of divided screens from a communication destination,
A process of receiving each divided screen sent in a predetermined order from the communication destination;
Using the received divided screens in the predetermined order, reconstructing the frame image with reference to header information including screen position information and size information added to each divided screen;
A computer program that causes a computer to execute.

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