The 4k HDMI receiver chip used in this project is ADV7619 from Analog Devices. The chip decodes the HDMI input from the camera or a PC and provides all the necessarily information required for video synchronization, processing and analysis. In this post we will show the vertical and horizontal synchronization signals, as well as actual pixels data. Before starting to receive the video stream the chip need to be programmed using I2C bus. For I2C programming I used FX3 development board from Cypress, more follows about it in the separate post.
Vertical synchronization – VSYNC: separates the video frames . One can use this signal to measure very precisely the frame rate of the video.This information is valuable for assuring the quality of the video feed. It may be used for example to see the actual frame-rate of the games.However, if frames are doubled, it wouldn’t detect it, and more sophisticated approach should be used: detection of the data change between the frames.This also can be achieved with Open Video FMC card and some VHDL programming. Here we see the VSYNC pulse at the oscilloscope, coming from Sony A7S DSLR camera via 4K HDMI receiver and measure it’s frequency = the framerate:
We clearly see 59.94 Frames per second. The whole setup picture is below. It shows Sony A7S connected the the open source 4K HDMI receiver that uses ADV7619 chip, Cypress FX3 USB3 board for configuration and data transfer to PC at amazing 320 MBytes per second, and the baseboard is KC705 from Xilinx.
Horizontal synchronization – HSYNC: separates the lines within a single video frame.This information may be used for example for activation of the video processing algorithms, synchronization with external devices etc.