sbus_ch_data[0] = ((int16_t)rx[ 1] >> 0 | ((int16_t)rx[ 2] << 8 )) & 0x07FF;

This line of code reads two bytes (8 bits each) from the array 'rx' at indices 1 and 2. It then combines them to form a 16-bit integer using bit shifting and bitwise OR operations.

First, the byte at index 1 is shifted 0 bits to the right (effectively leaving it unchanged) and then converted to a signed 16-bit integer type using typecasting. This value is then ORed with the byte at index 2, which is first shifted 8 bits to the left (multiplying it by 256) to make room for the first byte's bits. The result is a 16-bit integer that represents the first two channels of data from an SBUS receiver.

This process is likely repeated for several more channels of data, with each channel typically represented by a 16-bit integer in the 'sbus_ch_data' array.