Question: What happens to the speech frame produced by the AMR speech decoder when it receives a decoder homing frame while already in its home state?
Option 1: The speech frame is processed normally and outputted as is.
Option 2: The resulting speech frame is replaced by the encoder homing frame.
Option 3: The speech decoder skips producing a speech frame for that input.
Option 4: The speech decoder enters an error state due to conflicting inputs.
Explanation: According to the decoder homing process, if the AMR speech decoder is in its home state when it receives a decoder homing frame (corresponding to the used codec mode), the normal output speech frame (which would otherwise be unknown) is specifically replaced by the encoder homing frame. This ensures synchronization and resets the decoder's state for subsequent frames, supporting optimized implementation, especially in scenarios like the TRAU uplink direction.