Transmission system, transmission apparatus, and transmission method for transmitting video data

A transmission apparatus for transmitting 24 bit pixel data of an uncompressed image for one screen transmitted in one direction to a receiving apparatus by using a differential signal transmitted via a plurality of transition minimized differential signaling (TMDS) channels, the TMDS channels being operable to transmit data of a fixed number of bits per clock transition of a pixel clock in a valid image period, the valid image period being a period between sequential vertical synchronization signals and not including a horizontal blanking period and a vertical blanking period, the transmission apparatus comprising:

• a receiving unit that, via a display data channel (DDC) line, receives high resolution image data related information which indicates whether or not the receiving apparatus supports a high resolution image having pixel data of 30 bit, 36 bit or 48 bit, in which the high resolution image data related information is described in High Definition Multimedia Interface (HDMI) Vender Specific Definition Bit (VSDB) of Enhanced Extended Display Identification Data (E-EDID) stored in the receiving apparatus;
• a determination unit that determinates whether or not the receiving apparatus supports a high resolution image based on the high resolution image data related information;
• a transmitting unit that transmits high resolution image data in one direction to the receiving apparatus by using a differential signal transmitted via the plurality of TMDS channels in the valid image period, raising a frequency of the pixel clock, and inserting a color depth (CD) bit, which is related to a bit number of the high resolution image data, into a general control packet, the general control packet including a general control packet header and a general control subpacket including CD values, being transmitted during a data island period of the high resolution image data in one direction to the receiving apparatus, in which the CD values of CD2=1, CD1=0 and CD0=1 indicate 30 bits per pixel, the CD values of CD2=1, CD1=1 and CD0=0 indicate 36 bits per pixel, and the CD values of CD2=1, CD1=1 and CD0=1 indicate 48 bits per pixel,
• wherein, after the transmitting unit raises the frequency of the pixel clock, one pixel data of the high resolution image data of 30 bit transmitted in 1.25 pixel clock transitions, one pixel data of the high resolution image data of 36 bit transmitted in 1.5 pixel clock transitions, or one pixel data of the high resolution image data of 48 bit is transmitted in two pixel clock transitions, in which the high resolution image data is encrypted in accordance with High-Bandwidth Digital Content Protection (HDCP).