Interlaced Video - 3.2 English

The HDMI 1.4/2.0 TX Subsystem supports both AXI4-Stream video and native video interface.

• When AXI4-Stream is selected, an AXI4-Stream to Video Out core is used to support the HDMI 1.4/2.0 TX Subsystem. Because the AXI4-Stream carries only active video data, the AXI4-Stream to Video Out core takes input from an AXI4-Stream slave interface and converts it into a Native Video stream, which is then fed to the HDMI TX core.
• When Native Interface is selected, the native video stream must be prepared and fed to the NATIVE_VID_IN port of the HDMI 1.4/2.0 TX Subsystem, which is directly connected to the HDMI TX core inside the HDMI 1.4/2.0 TX Subsystem.
• When Native Interface (Vectored DE) is selected, the native video stream must be prepared and fed to the video_*_arb ports of the HDMI 1.4/2.0 TX Subsystem, which is directly connected to the HDMI TX core inside the HDMI 1.4/2.0 TX Subsystem.

The HDMI 1.4/2.0 TX Subsystem is designed to support both progressive and interlaced video. In this section, the focus is to show how to handle interlaced video as it is more straightforward for progressive video.

Taking 1920x1080@50 Hertz (I) as an example, the detailed timing information is shown in the following table.

For interlaced video, each frame consists of two fields. One field carries the odd lines and the other field carries the even lines. After putting both fields together, you get the complete frame. Therefore,

• Vertical Active per Field = Vertical Active Lines / 2
• Frame Rate = Field Rate / 2.

In this example,

• VActive = 1080/2 = 540
• Field Rate = 50 Hertz
• Frame Rate = 50/2 = 25 Hertz

To design using the AXI4-Stream Interface, generate two fields of video with timing using the values from the previous table. For complete timing information, refer to CTA-861-H. Only active video data compliant with AXI4-Stream protocol is needed. The AXI4-Stream to Video Out core inside the HDMI 1.4/2.0 TX Subsystem converts the AXI4-Stream video into native video. Ensure that fid is driven to align with the field video data. For details, refer to the AXI4-Stream to Video Out LogiCORE IP Product Guide (PG044).

To design using the Native interface, generate two fields of native video with timing using the values from the previous table. Ensure that the HSYNC and VSYNC are driven using the values from the previous table. Because a frame can have odd number of lines (for example, 1125 for 1080i50), the two fields might result in a different total number of lines (for example, Field 0 has 522 lines, and Field 1 has 523 lines).