After writing the image for master or slave, you should see at least two partitions from the card, “boot” and “VIDEO”. On the “VIDEO” partition, there is a file called “loop.mp4”. Replace this file with your content but keep the name. Or leave the file untouched for testing the network, and replace the videos after.
The filesystem is case-sensitive, so make sure the name is exactly like the original.
Also, the file has to be encoded with h264, as the player uses the hardware decoding of Raspberry Pi.
If you would like to change the file via ssh, make sure to remount the VIDEO partition so you can write to it.
Connect the players via ethernet
There are two simple ways to connect the Raspberries in order to sync playback:
For all i have experienced, if you do not want to install a router, using just a cable or an ethernet switch works fine, though it might take a bit longer to start up. The operating system works it out between clients, when there is no DHCP-server present. DHCP means there is a central service, usually in your internet router, that provides IP addresses to clients. MP4Museum-Sync needs a working IP network to sync playback.
I have not tested this on WiFi, and am unsure if it’s a good idea. But if anyone has tested, or is running this, please drop me a line! Thanks.