Hello,
I will forward this over to another forum where they may be able to give you more details. This board is designed to show how you can take in and process multiple HDMI signals so it is designed to use the audio that is on the HDMI connectors.
The board also has provisions for bringing in audio using the expansion connector, J10, to bring the audio directly into the SHARC processor. See page 15 of the schematics. You will have to write software for handling the audio from the SHARC and transferring it over to the ADV7625. Since it is up to you to program the interface then the audio format is your choice. You can do multiple streams of I2S or one or more TDM data streams. If you need to get the audio into digital form then you can use one of our CODEC evaluation boards to do that. If you need help with that part then send me a message.
Thanks,
Dave T