Just now I discovered that my video source was transmitting in 1080i format. Changing the source to transmitting at 720p the PiCapture now works just fine.
I am sorry for any inconvenience.
I still have two questions I would like you to answer (after having read your suppport database):
1. How do I communicate with the HD1 via the UART port having a RPi 3B+?
2. You are still not considering support for 1080i sources are you? We have quite a few 1080i sources out there which we would like to support by means of your HD1 board if possible.
If you wish to use Serial instead of I2C for communication, please follow the instructions in our documentation. The “Hardware installation” section shows the necessary jumper settings, and the “Software installation” describes what is required to set up the serial interface and use PiVideo. We will be glad to answer additional questions about the serial port if you have issues with this.
As described in our HD1 documentation, we have only very limited support for 1080i sources. The HD1 does not have the ability to de-interlace the video, and so in this mode it outputs quarter-resolution video at 960×540. The steps for this are described in our “Using PiCapture HD1” section of our online documentation. We do not have plans to implement full support for interlaced video on the HD1.