Hi Lo,
This mux settings is also correct, there is no module enabled in the path, mux is configured to accept YUV422 data from VIP1_A and store it as YUV422 data.
Now i can think of only one thing, can you probe the signals coming on VIP1A and see if they are really toggling during active period? Configuration is correct, even VIP is detecting correct input frame size, still if you are recieving frame contents as zero, data itself might be 0. To confirm this, it would be better to probe the signals and check this out.
Regards,
Brijesh