Patent Publication Number: US-2018048924-A1

Title: Transmission apparatus and transmission method, reception apparatus and reception method, transmission system, and program

Description:
TECHNICAL FIELD 
     The present technology relates to a transmission apparatus and a transmission method, a reception apparatus and a reception method, a transmission system, and a program and particularly to a transmission apparatus and a transmission method, a reception apparatus and a reception method, a transmission system, and a program by which efficient use of a communication bandwidth and a reduction in power consumption can be realized. 
     BACKGROUND ART 
     A standard of an interface that transmits image data to a display, which is called DisplayPort (trademark), is commonly used (e.g., see Non-Patent Literature 1). 
     CITATION LIST 
     Non-Patent Literature 
     Non-Patent Literature 1: DisplayPort (trademark) Version1.2a VESA (Video Electronics Standards Association) 
     DISCLOSURE OF INVENTION 
     Technical Problem 
     By the way, in the DisplayPort (trademark) standard, transmitting audio data in addition to visible image data formed of effective pixel data is defined. It is possible to transmit and receive them together. 
     In transmitting the audio data in addition to the visible image data formed of the effective pixel data in this DisplayPort (trademark) standard, an error correction function formed of 4-byte parity data is set with respect to 16-byte audio data. With this, the audio data is protected. 
     On the other hand, in this DisplayPort (trademark) standard, it is conceivable that other additional data instead of the audio data in addition to the visible image data formed of the effective pixel data can be transmitted by using a mechanism for transmitting the audio data. 
     However, in the DisplayPort (trademark) standard, there is a fear that this error correction function may be overprotective in transmitting and receiving, in addition to the visible image data, the additional data that does not require high reliability unlike the audio data. As a result, it can result in lowered communication efficiency and increased power consumption associated with communication. 
     The present technology has been made in view of the above-mentioned circumstances particularly to enable an enhancement of communication efficiency and a reduction in power consumption due to efficient use of a communication bandwidth in transmitting additional data in addition to visible image data in a communication standard used for an interface of the existing display port (DisplayPort (trademark)) to be realized. 
     Solution to Problem 
     A transmission apparatus according to an aspect of the present technology is a transmission apparatus that transmits visible image data formed of effective pixel data of an image pickup apparatus by using a format for transmitting to a display, the transmission apparatus including a transmitter that transmits audio data in addition to the visible image data, in which in the format, an error correction code having a predetermined amount is set with respect to the audio data having a predetermined amount, and the transmitter transmits, transmitting additional data different from the audio data instead of the audio data in addition to the visible image data, the additional data and the visible image data by using the format from which a part of the error correction code is omitted. 
     The transmitter can inquire a transmission destination about whether or not the additional data can be transmitted with the part of the error correction code included in the format being omitted, and transmit the additional data in addition to the visible image data by using the format from which the part of the error correction code is omitted if the additional data can be transmitted with the part of the error correction code included in the format being omitted. 
     The transmitter can use the format for transmitting to the display and packetize and transmit phase detection image data in the image pickup apparatus as the additional data. 
     The format for transmitting to the display can be a format defined by DisplayPort (trademark), and the transmitter can use an SDP (Secondary-Data Packet) defined by DisplayPort (trademark) as the format for transmitting to the display and packetize and transmit the phase detection image data as the additional data in the image pickup apparatus. 
     The transmitter can use a phase detection image information packet and a phase detection image data packet of the SDP (Secondary-Data Packet) defined by DisplayPort (trademark) and packetize and transmit the phase detection image data as the additional data in the image pickup apparatus. 
     The transmitter can arrange the phase detection image information packet in a vertical blanking region, arrange the phase detection image data packet in a horizontal blanking region, and packetize and transmit the phase detection image data. 
     The phase detection image information packet can include information on the number of lines per frame and the number of pixels per line of the phase detection image constituted by the phase detection image data, the number of bits per pixel, and the number of pixels per piece of the phase detection image data. 
     The transmitter can package and transmit the phase detection image data packet in units of predetermined bytes. 
     A transmission method for a transmission apparatus according to an aspect of the present technology is a transmission method for a transmission apparatus that transmits visible image data formed of effective pixel data of an image pickup apparatus by using a format for transmitting to a display, the transmission method including a transmission step of transmitting audio data in addition to the visible image data, in the format, an error correction code having a predetermined amount is set with respect to the audio data having a predetermined amount, and processing of the transmission step includes transmitting, transmitting additional data different from the audio data instead of the audio data in addition to the visible image data, the additional data and the visible image data by using the format from which a part of the error correction code is omitted. 
     A program according to an aspect of the present technology is a program that causes a computer that controls a transmission apparatus that transmits visible image data formed of effective pixel data of an image pickup apparatus by using a format for transmitting to a display to execute processing including a transmission step of transmitting phase detection image data in the image pickup apparatus in addition to the visible image data, in which in the format, an error correction code having a predetermined amount is set with respect to the audio data having a predetermined amount, and processing of the transmission step includes transmitting, transmitting additional data different from the audio data instead of the audio data in addition to the visible image data, the additional data and the visible image data by using the format from which a part of the error correction code is omitted. 
     A reception apparatus according to an aspect of the present technology is a reception apparatus that receives visible image data formed of effective pixel data of an image pickup apparatus by using a format for transmitting to a display, the reception apparatus including a receiver that receives audio data in the image pickup apparatus in addition to the visible image data, in which in the format, an error correction code having a predetermined amount is set with respect to the audio data having a predetermined amount, and the receiver receives, in receiving additional data different from the audio data instead of the audio data in addition to the visible image data, the additional data and the visible image data by using the format from which a part of the error correction code is omitted. 
     A reception method according to an aspect of the present technology is a reception method for a reception apparatus that receives visible image data formed of effective pixel data of an image pickup apparatus by using a format for transmitting to a display, the reception method including a step of receiving audio data in the image pickup apparatus in addition to the visible image data, in which in the format, an error correction code having a predetermined amount is set with respect to the audio data having a predetermined amount, and processing of the reception step includes receiving, in receiving additional data different from the audio data instead of the audio data in addition to the visible image data, the additional data and the visible image data by using the format from which a part of the error correction code is omitted. 
     A program according to an aspect of the present technology is a program that causes a computer that controls a reception apparatus that receives visible image data formed of effective pixel data of an image pickup apparatus by using a format for transmitting to a display to execute processing including a reception step of receiving audio data in the image pickup apparatus in addition to the visible image data, in the format, an error correction code having a predetermined amount is set with respect to the audio data having a predetermined amount, and processing of the reception step includes receiving, in receiving additional data different from the audio data instead of the audio data in addition to the visible image data, the additional data and the visible image data by using the format from which a part of the error correction code is omitted. 
     A transmission system according to an aspect of the present technology is a transmission system including: a transmission apparatus that transmits visible image data formed of effective pixel data of an image pickup apparatus by using a format for transmitting to a display; and a reception apparatus, in which the transmission apparatus includes a transmitter that transmits, to the reception apparatus, audio data in the image pickup apparatus in addition to the visible image data, in the format, an error correction code having a predetermined amount is set with respect to the audio data having a predetermined amount, the transmitter transmits, transmitting additional data different from the audio data instead of the audio data in addition to the visible image data, the additional data and the visible image data by using the format from which a part of the error correction code is omitted, the reception apparatus includes a receiver that receives, from the transmission apparatus, the audio data in the image pickup apparatus in addition to the visible image data, and the receiver receives, in receiving the additional data different from the audio data instead of the audio data in addition to the visible image data, the additional data and the visible image data by using the format from which the part of the error correction code is omitted. 
     The transmission apparatus and the reception apparatus according to the aspects of the present technology may be independent apparatuses or may be blocks that perform transmission processing. 
     Advantageous Effects of Invention 
     In accordance with the aspects of the present technology, it becomes possible to realize efficient use of a communication bandwidth and a reduction in power consumption in transmitting additional data in addition to visible image data in a communication standard used for an interface of the existing display port. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       [ FIG. 1 ] A diagram showing a configuration example of a first embodiment of a transmission system to which the present technology is applied. 
       [ FIG. 2 ] A diagram describing a ZAF pixel. 
       [ FIG. 3 ] A diagram describing MSA and SDP. 
       [ FIG. 4 ] A diagram describing MSA and SDP. 
       [ FIG. 5 ] A diagram describing a configuration of a phase detection image information packet of the SDP. 
       [ FIG. 6 ] A diagram describing a transmission form formed of a normal format of a phase detection image information packet of the SDP. 
       [ FIG. 7 ] A diagram describing a transmission form formed of a format from which parity of the phase detection image information packet of the SDP is omitted. 
       [ FIG. 8 ] A diagram describing a transmission form of a configuration of the phase detection image data packet of the SDP. 
       [ FIG. 9 ] A diagram describing a transmission form of the MSA. 
       [ FIG. 10 ] A diagram describing a configuration of the MSA. 
       [ FIG. 11 ] A diagram describing a configuration of the MSA. 
       [ FIG. 12 ] A flowchart describing transmission and reception processing by the transmission system of  FIG. 1 . 
       [ FIG. 13 ] A diagram describing a configuration example of a general-purpose personal computer. 
     
    
    
     MODE(S) FOR CARRYING OUT THE INVENTION 
     &lt;Configuration Example of Transmission System Using Secondary-Data Packet&gt; 
       FIG. 1  shows a configuration example of an embodiment of a transmission system to which the present technology is applied. The transmission system of  FIG. 1  is a system that transmits image data generated (captured) by an image pickup apparatus (not shown). 
     More specifically, the transmission system of  FIG. 1  is constituted by a transmitter  21  and a receiver  22 . In addition to visible image data supplied by the image pickup apparatus (not shown), the transmitter  21  transmits, to the receiver  22 , phase detection image data (ZAF image data) according to a format of DisplayPort (trademark) that is a standard for transmitting to a display, which is called SDP (Secondary-Data Packet). The receiver  22  receives the phase detection image data together with visible image data transmitted from the transmitter  21 . In the format of DisplayPort (trademark), which is called SDP (Secondary-Data Packet), transmitting the audio data in addition to the visible image data is defined. In the transmission system of  FIG. 1 , the phase detection image data is transmitted and received in addition to the visible image data instead of the audio data by using this format. Note that the phase detection image will be referred to as a ZAF image hereinafter. Further, in the present specification, it is assumed that an image is constituted by a plurality of pixels and image data is constituted by pixel data that is data on pixel values and the like of a plurality of pixels. 
     &lt;Regarding ZAF Pixel&gt; 
     In pixels set in an image pickup region, ZAF pixels are arranged at predetermined intervals in addition to effective pixels that generate visible image data. As such ZAF pixels, there are a left light shielding pixel with the left half of the pixel being shielded and a right light shielding pixel with the right half of the pixel being shielded. An image captured by each pixel is deviated to the left or right in a manner that depends on a focal distance. Therefore, regarding an image at a focal point, an image at the left light shielding pixel coincides with an image at the right light shielding pixel. Meanwhile, regarding an image deviated from the focal point, a phase difference depending on an amount of deviation of the focal distance is caused between the respective images. In view of this, it is possible to quickly adjust the focal point by determining the amount of deviation of the focal distance on the basis of this phase difference and adjusting the focal point. 
     ZAF pixels are arranged as shown in  FIG. 2 , for example.  FIG. 2  shows a pixel arrangement example within an effective pixel region. In  FIG. 2 , each square indicates a pixel. White squares are normal RGB pixels and squares the left or right half region of each of which is provided with a light shielding section shown by oblique lines are ZAF pixels. As shown in the figure, the ZAF pixels are alternately arranged at three-line intervals and at five-line intervals in a vertical direction and arranged at eight-pixel intervals in a horizontal direction. Therefore, in the example of  FIG. 2 , the number of ZAF pixels is set to be, in the horizontal direction, ⅛ of the total number of pixels of the effective pixel region and to be, in the vertical direction, ¼ of the total number of pixels of the effective pixel region. Therefore, in the example of  FIG. 2 , the number of ZAF pixels is 1/32 of the total number of pixels of the effective pixel region. 
     Next, configurations of the transmitter  21  and the receiver  22  in the transmission system of  FIG. 1  will be described. 
     The transmitter  21  includes an MSA generator  41 , an SDP generator  42 , a multiplexer  43 , a controller  44 , and an AUX (auxiliary communication unit)  45 . 
     The MSA generator  41  generates MSA (Main Stream Attributes) that are image property information such as the number of lines per frame, the number of pixels per line, the number of bits per pixel, and the like of image data (visible image data) formed of effective pixel data, which is to be transmitted, and supplies them to the multiplexer  43 . Note that the MSA will be described later in detail with reference to  FIGS. 9 to 11 . 
     The SDP generator  42  is controlled by the controller  44  to generate packets, which are called SDP (Secondary-Data Packets), according to a format for packetizing and transmitting ZAF pixel data in a horizontal blanking region and a vertical blanking region other than an effective pixel region and supplies them to the multiplexer  43 . Note that the SDP will be described later in detail with reference to  FIGS. 3 to 8 . 
     The multiplexer  43  multiplexes the MSA supplied from the MSA generator  41 , the SDP supplied from the SDP generator  42 , and image data (visible image data) formed of input effective pixel data and outputs them as multiplexed data. 
     The controller  44  comprehensively controls operations of the transmitter  21 . The controller  44  communicates with the receiver  22  that is a transmission destination via the AUX (auxiliary communication unit)  45 , determines whether or not the receiver  22  is compatible with a form from which parity is omitted, which will be described later, as the form of the SDP, and instructs the SDP generator  42  to generate the SDP in a manner that depends on the determination result. 
     The receiver  22  includes a division unit  61 , an MSA reader  62 , an SDP reader  63 , an image generator  64 , an AUX (auxiliary communication unit)  65 , a controller  66 , and a register  67 . The division unit  61  divides multiplexed data transmitted from the transmitter  21  into MSA, SDP, and visible image data and supplies the MSA to the MSA reader  62 , the SDP to the SDP reader  63 , and the visible image data to the image generator  64 . 
     The MSA reader  62  reads, on the basis of the supplied MSA, the information on the number of lines per frame, the number of pixels per line, and the number of bits per pixel of the visible image data and supplies the read information to the image generator  64 . 
     The SDP reader  63  is controlled by the controller  66  to read the SDP and extract and output the additional data such as the packetized ZAF image data. 
     The image generator  64  acquires visible image data and reconfigures and outputs the visible image on the basis of the information on the MSA. 
     The controller  66  comprehensively controls operations of the receiver  22 . The controller  66  communicates with the transmitter  21  via the AUX (auxiliary communication unit)  65 , reads information indicating whether or not the receiver  22  itself is compatible with a form in which the number of parity bytes is small, which will be described later, as the form of the SDP, and causes the transmitter  21  to transmit the result. Here, the information is stored in the register  67  in advance. Further, the controller  66  instructs the SDP reader  63  to perform corresponding processing on the basis of the information recorded in the register  67 , which indicates whether or not it is compatible with the form in which the number of parity bytes is small, which will be described later. 
     &lt;Regarding SDP (Secondary-Data Packet)&gt; 
     Next, the SDP will be described. 
     The SDP uses the horizontal blanking region and the vertical blanking region with respect to each frame and packetizes and transmits data other than the visible image data (effective pixel data). Further, the SDPs are classified into two types of phase detection image information packets and phase detection image data packets. 
     The phase detection image information packet is a packet including information on the number of lines per frame and the number of pixels per line of the ZAF image data, the number of bits per pixel, and the number of pixels per ZAF pixel data. 
     Further, the phase detection image data packet constitute a plurality of pieces of ZAF pixel data itself. 
     The phase detection image information packet and the phase detection image data packet are, for example, packetized data arranged as shown in  FIG. 3  within an image of one frame. 
     Note that, in  FIG. 3 , a region of ((number of effective pixels (Hwidth): X)×(number of effective lines (Vheight): Y)) shown in the lower right part is the effective pixel region  71 . Further, lines L 1  to L 15  within the effective pixel region  71  are lines in which the ZAF pixels are present. Regarding the intervals of the respective lines, if they are similar to  FIG. 2 , for example, the interval between the lines L 1  and L 2  is five lines, the interval between the lines L 2  and L 3  is three lines, and thereafter, the three lines and the five lines are alternately repeated as the intervals. 
     Above the effective pixel region  71 , there is provided a vertical blanking region (Vblank)  72 , in which MSA  81  and phase detection image information packets  82  of SDP are arranged. 
     Further, on a left-hand side of the effective pixel region  71 , there is provided a horizontal blanking region (Hblank)  73 . Phase detection image data packets  83 - 1  to  83 - 15  are arranged at a level lower by one line than each line in which the ZAF pixels in the effective pixel region  71  are present. Thus, also regarding lines in which the phase detection image data packets  83 - 1  to  83 - 15  are arranged, they are arranged at alternate intervals of the three lines and the five lines with respect to the vertical direction. Note that, if the phase detection image data packets  83 - 1  to  83 - 15  do not have to be distinguished from one another, they will be simply referred to as phase detection image data packets  83  and other configurations will be also referred in a similar way. 
     Thus, in  FIG. 3 , only about ¼ of the phase detection image data packets  83  is used in the horizontal blanking region (Hblank)  73 . In view of this, each phase detection image data packet  83  is divided into four parts and they are folded and arranged in lines in which no phase detection image data packet  83  is arranged. The arrangement as shown in  FIG. 4 , for example, can be thus obtained. With such an arrangement, it becomes possible to cause the horizontal blanking region (Hblank)  73  required by the phase detection image data packets  83  to be ¼ with respect to the horizontal direction. 
     &lt;Regarding Configuration of Phase Detection Image Information Packet&gt; 
     Next, a configuration of the phase detection image information packet  82  will be described with reference to  FIG. 5 . The packet header of the SDP defined by DisplayPort (trademark) is constituted by four bytes of HB 0  to HB 3  shown in the upper section of  FIG. 5 . In HB 0  that is a top byte, information for identifying a handled phase detection image is recorded. Therefore, with the same phase detection image, the same value is used. 
     In HB 1  that is a 2nd byte, information indicating a packet type (Secondary-Data Packet type) is recorded. In this HB 1 , for determining the display type in advance, a predetermined display type is set with respect to 00h to 07h while h08 to 0Fh are not set (DisplayPort RESERVED). In view of this, information indicating the phase detection image information packet is allocated to any of the not set 08h to 0Fh. For example, 08h may be allocated as the information indicating the phase detection image information packet. 
     HB 2  and HB 3  that are 3rd and 4th bytes are unused (Reserved (all 0)). 
     Regarding the data packets of the phase detection image information packet, as shown in the lower part of  FIG. 5 , information of low-order 8 bits of the number of lines per V of the phase detection image data is recorded in DB 0  that is a top byte. Further, information of high-order 8 bits of the number of lines per V of the phase detection image data is recorded in DB 1  that is a 2nd byte. The number of lines per V described here is the number of lines of the lines L 1  to L 15  in  FIG. 3 , for example. 
     In DB 2  that is a 3rh byte, information of low-order 8 bits of the number of pixels per H of the phase detection image data is recorded. Further, in DB 3  that is a 4th byte, information of high-order 8 bits of the number of pixels per V of the phase detection image data is recorded. The number of pixels per H described here is the number of phase detection pixels included in each of the lines L 1  to L 15  in  FIG. 3 , for example. 
     In DB 4  that is a 5th byte, information of low-order 8 bits of the number of pixels per packet of the phase detection image data packet is recorded. Further, in DB 5  that is a 6th byte, information of high-order 8 bits of the number of pixels per packet of the phase detection image data packet is recorded. 
     In DB 6  that is a 7th byte, information on the number of bits per pixel of the phase detection image data packet is recorded. Further, DB 7  to DB 15  that are 8th to 16th bytes are set to be unused regions (Reserved (all 0)). 
     &lt;Transmission Form in Normal Format&gt; 
     Next, a format in transmission of the SDP will be described with reference to  FIGS. 6 and 7 . Note that, although a case of the four lanes will be described in this example, another number of lanes may be employed. Note that the format in the transmission includes a normal format and one in the form that omits the parity. First of all, the normal format will be described with reference to  FIG. 6 . In the normal format, the transmission form of data chronologically arranged in an up-to-down direction regarding Lane 0 to Lane 3 from the left to the right as shown in  FIG. 6  is shown. Below control codes SS indicating the start of the SDP, the headers HB 0  to HB 3  are configured from the lane 0 to the lane 3 and one byte is arranged for each lane. 
     Below the headers HB 0  to HB 3  in the figure, parity PB 0  to PB 3  is configured and one byte is arranged for each of the lanes from the lane 0 to the lane 3. 
     Below the parity PB 0  to PB 3  in the figure, the data DB 0  to DB 15  are arranged with four bytes being downwardly arranged for each lane and a total of 16 bytes are arranged. Specifically, the data DB 0  to DB 3  are arranged with respect to the lane 0, the data DB 4  to DB 7  are arranged with respect to the lane 1, DB 8  to DB 11  are arranged with respect to the lane 2, and DB 12  to DB 15  are arranged with respect to the lane 3. 
     Below the data DB 0  to DB 15  of the respective lanes in the figure, parity PB 4  to PB 7  is configured and one byte is arranged for each of the lanes from the lane 0 to the lane 3. 
     In addition, regarding the lanes 0 to 2 below the parity PB 4  to PB 7  in the figure, each set of four bytes of the data DB 16  to DB 27  is arranged downwardly. That is, the data DB 16  to DB 19  are downwardly arranged with respect to the lane 0, DB 20  to DB 23  are downwardly arranged with respect to the lane 1, and DB 24  to DB 27  are downwardly arranged with respect to the lane 2. Note that data that should be transmitted is 28 bytes, and hence the lane 3 is set to be All 0s and blank. 
     In addition, below the data of each lane, the parity PB 8  to PB 11  is configured and one byte is arranged for each of the lanes from the lane 0 to the lane 3. In the bottom row, SE indicating the end of the SDP is arranged for each lane. 
     In this manner, the 4-byte parity is added to the 16-byte data and they are transferred. 
     &lt;Transmission Form in Format That is Form That Omits Parity&gt; 
     Next, the format in the form that omits the parity will be described with reference to  FIG. 7 . Note that configurations identical to those of the format described above with reference to  FIG. 6  will be denoted by identical names and descriptions thereof will be appropriately omitted. 
     That is, in the format in the form that omits the parity of  FIG. 7 , a difference from the format shown in  FIG. 6  is in that the parity PB 0  to PB 4  provided directly under the headers remains and other parity is deleted. 
     The normal format of  FIG. 6  is a format set in transmitting audio data in addition to the visible image data, and hence it is necessary to ensure the sound quality in real-time communication. Therefore, the 4-byte parity is provided for each set of 16-byte audio data. However, data added in the present technology is not audio data but phase detection image data. Even if any frame with lowered quality is present in real-time communication, it does not impose significant influence as long as it is normal in a next frame. Therefore, even if parity that is the error correction function is omitted with respect to the phase detection image data, its influence is small. In view of this, if data transmitted and received as the additional data does not require high quality in real-time communication, the format from which the parity is omitted as shown in  FIG. 7  is used. 
     By thus using the format from which the parity is omitted, it becomes possible to efficiently use the communication bandwidth and enhance the communication efficiency. Further, by omitting processing according to error correction using the parity, it becomes possible to reduce the power consumption. 
     Note that, with the format from which the parity is omitted, parity-omitted information indicating that the parity is omitted is recorded in, for example, the headers HB 0  to HB 3  or the control code SS. On the basis of this information, the receiver  22  is capable of immediately determining the presence/absence of the parity. 
     &lt;Configuration Example of Phase Detection Image Data Packet&gt; 
     Next, a configuration example of the phase detection image data packet will be described with reference to  FIG. 8 . Note that, the packet header of the phase detection image data packet is set to have a configuration similar to the phase detection image information packet described above with reference to  FIG. 5 , as shown in the upper section of  FIG. 8 . It should be noted that, regarding information indicating the display type of the header HB 1  that is a 2nd byte, any of values of h08 to 0Fh, which are not set (DisplayPort RESERVED), is allocated. For example, 09h may be allocated as the information indicating the phase detection image data packet. 
     Regarding the data packets of the phase detection image data packet, pieces of ZAF pixel data are sequentially stored in the data DB 0  to DB 15 . 
     For example, as shown in the middle section of  FIG. 8 , if ZAF pixel data AF0[9:0] to AF15[9:0] . . . , which are 10 bits and formed of data of a 0th bit to a ninth bit from the left in the figure, are configured, each set of 8 bits is allocated to the data DB 0  to DB 15  and transferred as shown in the lower section of  FIG. 8 . Note that, in the lower section of  FIG. 8 , data arrangement in being transmitted through the four lanes is shown and data arrangement of Lane 0 to Lane 3 from above is shown. Note that [9:0] indicates from the top bit (0) to a 10th bit (9). 
     That is, in the lane 0, AF1[9:2] of the top ZAF pixel data AF0[9:0] is allocated to the top one-byte data DB 0  from the left to the right in the figure. 
     Eight bits formed of AF0[1:0] of the top ZAF pixel data AF0[9:0] and AF4[9:4] of the 5th ZAF pixel data AF4[9:0] are allocated to the second one-byte data DB 1  of the lane 0. 
     Eight bits formed of AF4[3:0] of the 5th ZAF pixel data AF4[9:0] and AF8[9:6] of the 9th ZAF pixel data AF8[9:0] are allocated to the third one-byte data DB 2  of the lane 0. 
     Eight bits formed of the 9th ZAF pixel data AF8[5:0] and the 13th ZAF pixel data AF12[9:8] are allocated to the fourth one-byte data DB 3  of the lane 0. 
     Eight bits of the 13th ZAF pixel data AF12[7:0] are allocated to the fifth one-byte data DB 16  of the lane 0. 
     Further, in the lane 1, eight bits of the 2nd ZAF pixel data AF1[9:2] are allocated to top one-byte data DB 4 . 
     Eight bits formed of the 2nd ZAF pixel data AF1[1:0] and the 6th ZAF pixel data AF5[9:4] are allocated to the second one-byte data DB 5  of the lane 1. 
     Eight bits formed of the 6th ZAF pixel data AF5[3:0] and the 10th ZAF pixel data AF9[9:6] are allocated to the third one-byte data DB 6  of the lane 1. 
     Eight bits formed of the 10th ZAF pixel data AF9[5:0] and the 14th ZAF pixel data AF13[9:8] are allocated to the fourth one-byte data DB 7  of the lane 1. 
     Eight bits formed of the 14th ZAF pixel data AF13[7:0] are allocated to the fifth one-byte data DB 20  of the lane 1. 
     In addition, in the lane 2, eight bits of the 3rd ZAF pixel data AF2[9:2] are allocated to top one-byte data DB 8 . 
     Eight bits formed of the 3rd ZAF pixel data AF2[1:0] and the 7th ZAF pixel data AF6[9:4] are allocated to the second one-byte data DB 9  of the lane 2. 
     Eight bits formed of the 7th ZAF pixel data AF6[3:0] and the 11th ZAF pixel data AF10[9:6] are allocated to the third one-byte data DB 6  of the lane 2. 
     Eight bits formed of the 11th ZAF pixel data AF10[5:0] and the 15th ZAF pixel data AF14[9:8] are allocated to the fourth one-byte data DB 11  of the lane 2. 
     Eight bits of the  15 th ZAF pixel data AF14[7:0] are allocated to the fifth one-byte data DB 24  of the lane 2. 
     Further, in the lane 3, eight bits of the 4th ZAF pixel data AF3[9:2] are allocated to top one-byte data DB 12 . 
     Eight bits formed of the 4th ZAF pixel data AF3[1:0] and the 8th ZAF pixel data AF7[9:4] are allocated to the second one-byte data DB 13  of the lane 3. 
     Eight bits formed of the 8th ZAF pixel data AF7[3:0] and the 12th ZAF pixel data AF11[9:6] are allocated to the third one-byte data DB 14  of the lane 3. 
     Eight bits formed of the 12th ZAF pixel data AF11[5:0] and the 16th ZAF pixel data AF15[9:8] are allocated to the fourth one-byte data DB 15  of the lane 3. 
     Eight bits of the 16th ZAF pixel data AF15[7:0] are allocated to the fifth one-byte data DB 28  of the lane 3. 
     Note that the transmission form is similar to that of the phase information image information packet described above with reference to  FIGS. 6 and 7 . Therefore, a description thereof will be omitted. 
     That is, by using the format based on the SDP, it becomes possible to packetize and transmit and receive the ZAF pixel data. 
     &lt;Regarding MSA&gt; 
     Next, the MSA will be described with reference to  FIGS. 9 to 11 . 
     During transmission, the MSA are arranged as shown in  FIG. 9 . In  FIG. 9 , an arrangement example of the MSA with four lanes is shown. Lane  0  to Lane  3  are shown from the left and chronologically arranged in the up-to-down direction. 
     Regarding each lane, SS indicating the start of the MSA is continuously arranged twice. 
     Next, regarding each lane, Mvid23:16, Mvid15:8, and Mvid7:0 from above, which indicate clock frequencies of an identical video stream, are arranged on a byte-by-byte basis. Here, Mvid is information on the clock frequency of the video stream and Mvid23:16 is information of 16th to 23rd bits of the clock frequency of the video stream. Further, Mvid15:8 is information of 8th to 15th bits of the clock frequency of the video stream. In addition, Mvid7:0 is information of 0th to 7th bits of the clock frequency of the video stream. 
     Regarding Lane0, Htotal15:8 and Htotal7:0 are respectively arranged on a byte-by-byte basis below Mvid. Htotal is the number of pixels in a horizontal direction adding the effective pixel region  71  and the horizontal blanking region  73  as shown in the upper section of  FIG. 10 . Htotal15:8 and Htotal7:0 are respectively information of 8th to 15th bits of Htotal and information of 0th to 7th bits. 
     Regarding Lane0, Vtotal15:8 and Vtotal7:0, each of which corresponds to one byte, are arranged below Htotal. Vtotal is the number of lines in a vertical direction adding the number of effective lines of the effective pixel region  71  and the vertical blanking region  72  as shown in the upper section of  FIG. 10 . Vtotal15:8 and Vtotal7:0 are respectively information of 8th to 15th bits of Vtotal and information of 0th to 7th bits. 
     Regarding Lane0, HSP/HSW14:8 and HSW7:0, each of which corresponds to one byte, are arranged below Vtotal. HSP is information of one bit indicating a polarity of Hsync (horizontal synchronization signal), active high is 0 and active low is 1 as shown in the middle section of  FIG. 10 . Further, HSW indicates a pulse width of Hsync. HSP/HSW14:8 is information for one bit of HSP and information of 8th to 14th bits of HSW. HSW7:0 is information of 0th to 7th bits of HSW. 
     Regarding Lane1, Hstart15:8 and Hstart7:0, each of which corresponds to one byte, are arranged below Mvid. As shown in the lower section of  FIG. 10 , Hstart is obtained by defining a time from a timing at which last data of a previous line (last data of previous line) ends to a timing at which Hsync arises with the number of pixels. Hstart15:8 and Hstart7:0 are respectively information of 8th to 15th bits of Hstart and information of 0th to 7th bits. 
     Regarding Lane1, Vstart15:8 and Vstart7:0, each of which corresponds to one byte, are arranged below Hstart. As shown in the middle section of  FIG. 10 , Vstart is obtained by defining a time from a timing at which last Hsync of the previous frame (last H of previous frame) arises to a timing at which Vsync (vertical synchronization signal) arises with the number of lines. Vstart15:8 and Vstart7:0 are respectively information of 8th to 15th bits of Vstart and information of 0th to 7th bits. 
     Regarding Lane1, VSP/VSW14:8 and VSW7:0, each of which corresponds to one byte, are arranged below Vstart. VSP is information of one bit indicating a polarity of Vsync (vertical synchronization signal). As shown in the middle section of  FIG. 10 , active high is 0 and active low is 1. Further, VSW indicates a pulse width of Vsync. VSP/VSW14:8 is information of one bit of VSP and information of 8th to 14th bits of VSW. VSW7:0 is information of 0th to 7th bits of VSW. 
     On the other hand, regarding Lane2, Hwidth15:8 and Hwidth7:0, each of which corresponds to one byte, are arranged below Mvid. Hwidth is the number of pixels in the horizontal direction of the effective pixel region  71  as shown in the upper part of  FIG. 10 . Hwidth5:8 and Hwidth7:0 are respectively information of 8th to 15th bits of Hwidth and information of 0th to 7th bits. 
     Regarding Lane2, Vheight15:8 and Vheight7:0, each of which corresponds to one byte, are arranged below Hwidth. Vheight is the number of lines in the vertical direction of the effective pixel region  71  as shown in the upper part of  FIG. 10 . Vheight5:8 and Vheight7:0 are respectively information of 8th to 15th bits of Hheight and information of 0th to 7th bits. Note that, regarding Lane2, two bytes below Vheight are set to be blank (All 0s). 
     Regarding Lane3, Nvid23:16, Nvid15:8, and Nvid7:0 from above, each of which corresponds to one byte, are arranged below Mvid. Nvid is a link clock frequency. Nvid23:16, Nvid15:8, and Nvid7:0 are respectively information of 23rd to 16th bits of Nvid, information of 8th to 15th bits, and information of 0th to 7th bits. 
       Note that Video Stream clock [Mz]=Mvid/Nvid×Link clock [Mz].
 
     Regarding Lane3, MISC0_7:0 and MISC1_7:0 from above, each of which corresponds to one byte, are arranged below Nvid. MISC0_7:0 and MISC1_7:0 are information on an encoding format. 
     &lt;Regarding Encoding Format Shown in MISC&gt; 
     MISC0_7:0 and MISC1_7:0 records the information on the encoding format as shown in  FIG. 11 , for example. 
     That is, as shown in the uppermost row of the upper section of  FIG. 11 , if the 7th bit of MISC1 is 0 and the 1st to 4th bits of MISC0 are 0000, it indicates that the format is an RGB unspecified color space (legacy RGB mode). In addition, if 5th to 7th bits of MISC0 are 000, 001, 010, 011, or 100, it indicates that they are respectively 6, 8, 10, 12, or 16 bits/color. 
     As shown in the second row of the upper section of  FIG. 11 , if the 7th bit of MISC1 is 0 and 1st to 4th bits of MISC0 are 0010, it indicates that the format is CEA RGB (sRGB primaries). In addition, if 5th to 7th bits of MISC0 are 000, 001, 010, 011, or 100, it indicates that they are respectively 6, 8, 10, 12, or 16 bits/color. 
     As shown in the third row of the upper section of  FIG. 11 , if the 7th bit of MISC1 is 0 and 1st to 4th bits of MISC0 are 1100, it indicates that the format is RGB wide gamut fixed point (XR8, XR10, XR12). In addition, if 5th to 7th bits of MISC0 are 001, 010, or 011, it indicates that they are respectively 8, 10, or 12 bits/color. 
     As shown in the fourth row of the upper section of  FIG. 11 , if the 7th bit of MISC1 is 0 and 1st to 4th bits of MISC0 are 1101, it indicates that the format is RGB wide gamut fixed point (scRGB). In addition, if 5th to 7th bits of MISC0 are 100, it indicates that they are 16 bits/color. 
     As shown in the fifth row of the upper section of  FIG. 11 , the 7th bit of MISC1 is 1 and 1st to 4th bits of MISC0 are 0000, it indicates that the format is Y-only (luminance only). In addition, if 5th to 7th bits of MISC0 are 001, 010, 011, or 100, it indicates that they are respectively 8, 10, 12, or 16 bits/luminance. 
     As shown in the sixth row of the upper section of  FIG. 11 , if the 7th bit of MISC1 is 0, the 1st and 2nd bits of MISC0 are 01 or 10, the 3rd bit is 1, and the 4th bit is 0 or 1, it indicates that the format is YCbCr (ITU601/ITU709). Further, at this time, it is 422 format if the 1st and 2nd bits are 01 or it is 444 format if the 1st and 2nd bits are 10. In addition, at this time, if the 4th bit is 0, it indicates that the format is YCbCr (ITU601), or if the 4th bit is 1, it indicates that the format is YCbCr (ITU709). Further, if 5th to 7th bits of MISC0 are 001, 010, 011, or 100, it indicates that they are respectively 8, 10, 12, or 16 bits/color. 
     As shown in the seventh row of the upper section of  FIG. 11 , if the 7th bit of MISC1 is 0, the 1st and 2nd bits of MISC0 are 01 or 10, the 3rd bit is 0, and the 4th bit is 0 or 1, it indicates that the format is xvYCC (xvYCC601/xvYCC709). At this time, it is 422 format if the 1st and 2nd bits are 01 or it is 444 format if the 1st and 2nd bits are 10. Further, if the 4th bit is 0, it indicates that the format is xvYCC (xvYCC601), or if the 4th bit is 1, it indicates that the format is xvYCC (xvYCC709). In addition, if 5th to 7th bits of MISC0 are 001, 010, 011, or 100, it indicates that they are respectively 8, 10, 12, or 16 bits/color. 
     As shown in the eighth row of the upper section of  FIG. 11 , if the 7th bit of MISC1 is 0 and the 1st to 4th bits of MISC0 are 0011, it indicates that the format is Adobe (trademark) RGB. In addition, if 5th to 7th bits of MISC0 are 000, 001, 010, 011, or 100, it indicates that they are respectively 6, 8, 10, 12, or 16 bits/color. 
     As shown in the ninth row of the upper section of  FIG. 11 , if the 7th bit of MISC1 is 0 and the 1st to 4th bits of MISC0 are 1110, it indicates that the format is DCI-P3. In addition, if 5th to 7th bits of MISC0 are 011 and 100, it indicates that they are respectively 12 or 16 bits/color. 
     As shown in the  10 th row of the upper section of  FIG. 11 , if the 7th bit of MISC1 is 0 and the 1st to 4th bits of MISC0 are 1111, it indicates that the format is Color Profile. In addition, if 5th to 7th bits of MISC0 are 001, 010, 011, or 100, it indicates that they are respectively 8, 10, 12, or 16 bits/color. 
     As shown in the uppermost row of the lower section of  FIG. 11 , the 0th bit of MISC0 is a (Video Stream_Clk/LS_CLK) synchronization flag between a video stream clock and a link clock, where 0 indicates asynchronization and 1 indicates synchronization. In a case of synchronization, Mvid becomes a fixed value. 
     As shown in the second row of the lower section of  FIG. 11 , the 0th bit of MISC1 is an even-number flag indicating whether or not Vtotal number in a case of the interlace is an even number, where 1 indicates an even number and 0 indicates an odd number. 
     As shown in the third row of the lower section of  FIG. 11 , the 1st to 2nd bits of MISC1 indicate stereoscopic video (3D) characteristics and 00 indicates being non-stereoscopic or transmitting a stereoscopic image by using a video stream configuration (VSC) of the SDP. Further, if the 1st to 2nd bits of MISC1 are 01, it indicates that the next frame is a progressive right-eye image (RIGHT_EYE@Side-by-Side, progressive). At this time, it indicates that the top image is a right-eye image of the interlace (RIGHT_EYE@Top, interlace) and the bottom image is a left-eye image of the interlace (LEFT_EYE@Bottom, interlace). Further, if the 1st to 2nd bits of MISC1 are 10, it indicates being not set (Reserved), or if the 1st to 2nd bits of MISC1 are 11, it indicates that the next frame is a progressive left-eye image (LEFT_EYE@Side-by-Side, progressive), where it indicates that the top image is an interlace left-eye image (LEFT_EYE@Top, interlace) and the bottom image is an interlace right-eye image (RIGHT_EYE@Bottom, interlace). 
     Note that the 4th to 6th bits of MISC1 are not set (Reserved). Therefore, for example, information required for identifying a transmission source may be added to the 4th to 6th bits of MISC1. 
     By doing so, it becomes possible to identify a device that is a transmission source of visible image data including ZAF image data. For example, adding information indicating that an image transmission source is an image sensor enables the fact that the transmission source is an image sensor such as an image pickup device, for example, to be recognized. 
     &lt;Transmission and Reception Processing&gt; 
     Next, transmission and reception processing in the transmission system of  FIG. 1  will be described with reference to the flowchart of  FIG. 12 . 
     In Step S 11 , the controller  44  of the transmitter  21  controls the AUX (auxiliary communication unit)  45  to inquires the receiver  22  about whether or not the processing compatible with the format from which the parity is omitted is possible and check it. 
     In Step S 31 , the controller  66  of the receiver  22  controls the AUX (auxiliary communication unit)  65  to determine whether or not the inquiry about whether or not the processing compatible with the format from which the parity is omitted is possible has been received from the transmitter  21 . In Step S 31 , for example, if it is determined in the processing of Step S 11  that the inquiry about whether or not the processing compatible with the format from which the parity is omitted is possible has been received, the processing proceeds to Step S 32 . 
     In Step S 32 , the controller  66  checks information stored in the register  67  and reads parity-compatible information indicating whether or not the processing compatible with the format from which the parity is omitted is possible. The register  67  described here is, for example, a region not set (Reserved) of 0090h to 00FFh included in Capabirity field in DPCD (DisplayPort Configuration Data) defined by DisplayPort (trademark). In this case, the parity-compatible information indicating whether or not the processing compatible with the format from which the parity is omitted is possible is recorded in advance in the region not set (Reserved) of 0090h to 00FFh included in this Capabirity field. 
     In Step S 33 , the controller  66  controls the AUX  65  to transmit the parity-compatible information indicating whether or not the processing compatible with the format from which the parity is omitted is possible, which is read from the register  67 , to the transmitter  21 . 
     In the step  12 , the controller  44  of the transmitter  21  controls the AUX  45  to determine whether or not the processing compatible with the format from which the parity is omitted is possible, on the basis of the parity-compatible information indicating whether or not the processing compatible with the format from which the parity is omitted is possible, which is transmitted from the receiver  22 . 
     In Step S 12 , for example, if it is determined in Step S 13  that the parity-compatible information is the information indicating that the processing compatible with the format from which the parity is omitted is possible, the controller  45  instructs the SDP generator  42  to generate the SDP by using the format from which the parity is omitted. Note that, if it is determined in Step S 12  that the parity-compatible information indicates that the processing compatible with the format from which the parity is omitted is not possible or if the parity-compatible information is not transmitted, the processing of Step S 13  is skipped. Thus, in this case, the SDP generator  42  generates the SDP by using the normal format. 
     In Step S 14 , the MSA generator  41  generates the above-mentioned MSA of visible image data to be transmitted, which are formed of information on the number of lines per frame, the number of pixels per line, and the number of bits per pixel of phase detection image data, and supplies them to the multiplexer  43 . 
     In Step S 15 , the SDP generator  42  generates the above-mentioned SDP on the basis of the ZAF image data. That is, if the SDP generator  42  is instructed to generate the SDP by using the format from which the parity is omitted through the processing of Step S 13  on the basis of the parity-compatible information, the SDP generator  42  generates the phase detection image information packet and the phase detection image data packet in the SDP by using the format from which the parity is omitted. In this case, the SDP generator  42  records the parity-omitted information indicating the format from which the parity is omitted, in the headers HB 0  to HB 3 , the control code SS, or the like. Further, if the processing of Step S 13  is skipped, the SDP generator  42  generates the SDP by using the normal format from which the parity is not omitted. 
     In Step S 16 , the multiplexer  43  multiplexes the MSA, the SDP, and the visible image data to generate multiplexed data. 
     In Step S 17 , the multiplexer  43  transmits the multiplexed data to the receiver  22 . 
     In Step S 18 , the transmission unit  21  determines whether or not a next image signal is absent and an instruction to terminate the processing is performed. If the instruction to terminate the processing is not performed, the processing returns to 
     Step S 14  and the subsequent processing is repeated. Then, if the instruction to terminate the processing is performed in Step S 18 , the processing ends. 
     On the other hand, in the receiver  22 , the division unit  61  receives the multiplexed data in Step S 34 . 
     In Step S 35 , the division unit  61  divides the multiplexed data into the MSA, the SDP, and the visible image data and supplies the MSA to the MSA reader  62 , the SDP to the SDP reader  63 , and the visible image data to the image generator  64 . 
     In Step S 36 , the MSA reader  62  reads, from the information on the MSA, the information on the number of lines per frame, the number of pixels per line, and the number of bits per pixel of the visible image data, and supplies it to the image generator  64 . 
     In Step S 37 , the controller  66  checks the headers HB 0  to HB 3  or the control code SS, checks the presence/absence of the parity-omitted information, and instructs the SDP reader  63  to perform processing as being in the format from which the parity is omitted or perform processing as being in the normal format. In accordance with this instruction, the SDP reader  63  reads the phase detection image information packet and the phase detection image data packet of the SDP and extracts the ZAF image data from the phase detection image data on the basis of the information on the phase detection image information packet and outputs it. Thus, if the parity-omitted information is present, the SDP reader  63  reads the SDP as being in the format from which the parity is omitted. Further, if the parity-omitted information is not present and handling has to be performed as being in the normal format or if the parity-omitted information is not present, the SDP reader  63  reads the SDP as being in the normal format. 
     In Step S 38 , the image generator  64  reconfigures the visible image from the visible image data on the basis of the MSA and outputs it. 
     In Step S 39 , the receiver  22  determines whether or not a next image signal is absent and an instruction to terminate the processing is performed. If the instruction to terminate the processing is not performed, the processing returns to Step S 34  and the subsequent processing is repeated. Then, if the instruction to terminate the processing is performed in Step S 39 , the processing ends. 
     Note that the example in which, for starting the transmission and reception processing, the transmitter  21  inquires the receiver  22 , checks whether or not it is compatible with the format from which the parity is omitted, and instructs the SDP generator  42  to generate the SDP by using the format depending on the check result has been described above. However, if the receiver  22  cannot check from the transmitter  21  whether or not it is compatible with the format from which the parity is omitted, it may be considered that it is not compatible with the format from which the parity is omitted and processing may be performed by using the normal format. 
     Further, if receiving the multiplexed data before inquired about whether or not it is compatible with the format from which the parity is omitted, the receiver  22  may skip the processing of Steps S 31  to S 33  and start the processing from Step S 34  and perform processing as being in the normal format. 
     In addition, whether or not to use the format from which the parity is omitted may be determined in a manner that depends on the type of the additional data and the format may be switched in a manner that depends on needs. 
     Although the example in which the ZAF image data is transmitted and received as the additional data has been described above, other data may be transmitted and received in accordance with a similar technique. For example, thumbnail images or the like may be transmitted and received. If additional data that does not require real-time reliability like thumbnail images or the like, the parity may be omitted. Further, as a matter of course, audio data can also be transmitted as the additional data through similar processing. In this case, error correction information formed of the parity is used as it is. Therefore, the processing of Steps S 11  to S 13  and Steps S 31  to S 33  is skipped. 
     In the above-mentioned processing, the SDP is used and the ZAF image data is packetized. Thus, it becomes possible to transmit the visible image data and to add the packetized ZAF image data to the horizontal blanking region and the vertical blanking region and transmit them. 
     Further, in the above-mentioned processing, in a manner that depends on the type of the additional data and whether or not the receiver  22  is compatible with the format without the parity, it becomes possible to use the format for transmitting the SDP by switching the presence/absence of the parity. With this, in a case where audio data or the like is transmitted and received as the additional data as is conventionally done, real-time transmission and reception having high reliability are made possible by adding  4 -byte parity to 16 bytes. Further, in transmitting the additional data such as the ZAF image and the thumbnail image, for which the real-time reliability should not be considered as important, it becomes possible to enhance the communication efficiency and reduce the power consumption associated with the communication by using the format from which the error correction function of the parity is omitted. 
     By the way, the above-mentioned series of processing may be executed by hardware or may be executed by software. If the series of processing is executed by software, programs that configure that software are installed, from the recording medium, in a computer incorporated in dedicated hardware or for example, a general-purpose personal computer capable of executing various functions by installing various programs. 
       FIG. 13  shows a configuration example of a general-purpose personal computer. This personal computer includes a built-in CPU (Central Processing Unit)  1001 . An input/output interface  1005  is connected to the CPU  1001  via a bus  1004 . A ROM (Read Only Memory)  1002  and a RAM (Random Access Memory)  1003  are connected to the bus  1004 . 
     A communication unit  1009  is connected to the input/output interface  1005 . The communication unit  1009  is constituted by an input unit  1006  constituted by input devices such as a keyboard and a mouse into which a user inputs operation commands, an output unit  1007  that outputs processing operation screens and images of processing results to a display device, a storage unit  1008  constituted by a hard disk drive that stores programs and various types of data and the like, a LAN (Local Area Network) adaptor, and the like. The communication unit  1009  executes communication processing via a network represented by the Internet. Further, a drive  1010  is connected thereto. The drive  1010  reads and writes data from/in the removable medium  1011  such as a magnetic disk (including flexible disk), an optical disc (including CD-ROM (Compact Disc-Read Only Memory) and DVD (Digital Versatile Disc)), a magneto-optical disk (including MD (Mini Disc)), and a semiconductor memory. 
     The CPU  1001  executes various types of processing in accordance with the programs stored in the ROM  1002  or programs read from a removable medium  1011  such as a magnetic disk, an optical disc, a magneto-optical disk, and a semiconductor memory, installed into the storage unit  1008 , and loaded into the RAM  1003  from the storage unit  1008 . Data and the like necessary for the CPU  1001  to execute various types of processing are further stored in the RAM  1003  if necessary. 
     In the thus configured computer, the CPU  1001  loads, for example, programs stored in the storage unit  1008  into the RAM  1003  via the input/output interface  1005  and the bus  1004  and executes them. In this manner, the above-mentioned series of processing is performed. 
     Programs executed by the computer (CPU  1001 ) can be, for example, recorded and provided in the removable medium  1011  that is a package medium. Further, the programs can be provided via a wired or wireless transmission medium such as a local area network, the Internet, and digital satellite broadcasting. 
     In the computer, the programs can be installed into the storage unit  1008  via the input/output interface  1005  by the removable medium  1011  being mounted on the drive  1010 . Further, the programs can be received by the communication unit  1009  via the wired or wireless transmission medium and installed into the storage unit  1008 . Otherwise, the programs can be installed into the ROM  1002  and the storage unit  1008  in advance. 
     Note that the programs executed by the computer may be programs are processed chronologically in the order described in the present specification or may be programs processed concurrently or at necessary timings, for example, upon calling. 
     Therefore, a plurality of apparatuses housed in separate casings and connected via a network and a single apparatus including a plurality of modules housed within a single casing are both systems. 
     Note that embodiments of the present technology are not limited to the above-mentioned embodiments and various modifications can be made without departing from the gist of the present technology. 
     For example, the present technology can take a cloud computing configuration in which a single function is shared and cooperatively processed by a plurality of apparatuses via a network. 
     Further, the respective steps described above with reference to the above-mentioned flowcharts can be shared and executed by a plurality of apparatuses rather than being executed by a single apparatus. 
     In addition, if a single step includes a plurality of processes, the plurality of processes of the single step can be shared and executed by a plurality of apparatuses rather than being executed by a single apparatus. 
     It should be noted that the present technology can also take the following configurations.
     (1) A transmission apparatus that transmits visible image data formed of effective pixel data of an image pickup apparatus by using a format for transmitting to a display, the transmission apparatus including   

     a transmitter that transmits audio data in addition to the visible image data, in which 
     in the format, an error correction code having a predetermined amount is set with respect to the audio data having a predetermined amount, and 
     the transmitter transmits, transmitting additional data different from the audio data instead of the audio data in addition to the visible image data, the additional data and the visible image data by using the format from which a part of the error correction code is omitted.
     (2) The transmission apparatus according to (1), in which   

     the transmitter inquires a transmission destination about whether or not the additional data can be transmitted with the part of the error correction code included in the format being omitted, and transmits the additional data in addition to the visible image data by using the format from which the part of the error correction code is omitted if the additional data can be transmitted with the part of the error correction code included in the format being omitted.
     (3) The transmission apparatus according to (1) or (2), in which   

     the transmitter uses the format for transmitting to the display and packetizes and transmits the phase detection image data in the image pickup apparatus as the additional data.
     (4) The transmission apparatus according to (3), in which   

     the format for transmitting to the display is a format defined by DisplayPort (trademark), and 
     the transmitter uses an SDP (Secondary-Data Packet) defined by DisplayPort (trademark) as the format for transmitting to the display and packetizes and transmits the phase detection image data as the additional data in the image pickup apparatus.
     (5) The transmission apparatus according to (4), in which   

     the transmitter uses a phase detection image information packet and a phase detection image data packet of the SDP (Secondary-Data Packet) defined by DisplayPort (trademark) and packetizes and transmits the phase detection image data as the additional data in the image pickup apparatus.
     (6) The transmission apparatus according to (5), in which   

     the transmitter arranges the phase detection image information packet in a vertical blanking region, arranges the phase detection image data packet in a horizontal blanking region, and packetizes and transmits the phase detection image data.
     (7) The transmission apparatus according to (5), in which   

     the phase detection image information packet includes information on the number of lines per frame and the number of pixels per line of the phase detection image constituted by the phase detection image data, the number of bits per pixel, and the number of pixels per piece of the phase detection image data.
     (8) The transmission apparatus according to (5), in which   

     the transmitter packages and transmits the phase detection image data packet in units of predetermined bytes.
     (9) A transmission method for a transmission apparatus that transmits visible image data formed of effective pixel data of an image pickup apparatus by using a format for transmitting to a display, the transmission method including   

     a transmission step of transmitting audio data in addition to the visible image data, 
     in the format, an error correction code having a predetermined amount is set with respect to the audio data having a predetermined amount, and 
     processing of the transmission step includes transmitting, transmitting additional data different from the audio data instead of the audio data in addition to the visible image data, the additional data and the visible image data by using the format from which a part of the error correction code is omitted. ( 10 ) A program that causes a computer that controls a transmission apparatus that transmits visible image data formed of effective pixel data of an image pickup apparatus by using a format for transmitting to a display to execute 
     processing including a transmission step of transmitting phase detection image data in the image pickup apparatus in addition to the visible image data, in which 
     in the format, an error correction code having a predetermined amount is set with respect to the audio data having a predetermined amount, and 
     processing of the transmission step includes transmitting, transmitting additional data different from the audio data instead of the audio data in addition to the visible image data, the additional data and the visible image data by using the format from which a part of the error correction code is omitted.
     (11) A reception apparatus that receives visible image data formed of effective pixel data of an image pickup apparatus by using a format for transmitting to a display, the reception apparatus including   

     a receiver that receives audio data in the image pickup apparatus in addition to the visible image data, in which 
     in the format, an error correction code having a predetermined amount is set with respect to the audio data having a predetermined amount, and 
     the receiver receives, in receiving additional data different from the audio data instead of the audio data in addition to the visible image data, the additional data and the visible image data by using the format from which a part of the error correction code is omitted.
     (12) A reception method for a reception apparatus that receives visible image data formed of effective pixel data of an image pickup apparatus by using a format for transmitting to a display, the reception method including   

     a step of receiving audio data in the image pickup apparatus in addition to the visible image data, in which 
     in the format, an error correction code having a predetermined amount is set with respect to the audio data having a predetermined amount, and 
     processing of the reception step includes receiving, in receiving additional data different from the audio data instead of the audio data in addition to the visible image data, the additional data and the visible image data by using the format from which a part of the error correction code is omitted.
     (13) A program that causes a computer that controls a reception apparatus that receives visible image data formed of effective pixel data of an image pickup apparatus by using a format for transmitting to a display to execute   

     processing including a reception step of receiving audio data in the image pickup apparatus in addition to the visible image data, 
     in the format, an error correction code having a predetermined amount is set with respect to the audio data having a predetermined amount, and 
     processing of the reception step includes receiving, in receiving additional data different from the audio data instead of the audio data in addition to the visible image data, the additional data and the visible image data by using the format from which a part of the error correction code is omitted.
     (14) A transmission system including:   

     a transmission apparatus that transmits visible image data formed of effective pixel data of an image pickup apparatus by using a format for transmitting to a display; and 
     a reception apparatus, in which 
     the transmission apparatus includes
         a transmitter that transmits, to the reception apparatus, audio data in the image pickup apparatus in addition to the visible image data,       

     in the format, an error correction code having a predetermined amount is set with respect to the audio data having a predetermined amount, 
     the transmitter transmits, transmitting additional data different from the audio data instead of the audio data in addition to the visible image data, the additional data and the visible image data by using the format from which a part of the error correction code is omitted, 
     the reception apparatus includes
         a receiver that receives, from the transmission apparatus, the audio data in the image pickup apparatus in addition to the visible image data, and   the receiver receives, in receiving the additional data different from the audio data instead of the audio data in addition to the visible image data, the additional data and the visible image data by using the format from which the part of the error correction code is omitted.       

     REFERENCE SIGNS LIST 
       21  transmitter,  22  receiver,  41  MSA generator,  42  SDP generator,  43  multiplexer,  44  controller,  45  AUX (auxiliary communication unit),  61  division unit,  62  MSA reader,  63  SDP reader,  64  image generator,  65  AUX (auxiliary communication unit),  66  controller,  67  register