Question: In the EVS codec for NB signals, how is the hangover period handled after the last run of three consecutive active primary SAD decisions?
Option 1: The SAD decision is automatically set to inactive for a fixed window of 4 frames.
Option 2: The threshold is increased by 5.2 if one condition is met and by 2 if another condition is met, without altering the SAD decision directly.
Option 3: The threshold is decreased by 5.2 under one condition and by 2 under another, with the SAD decision based on comparing the average SNR to this corrected threshold.
Option 4: The hangover period does not affect the SAD decision, which remains dependent solely on the primary SAD flag.
Explanation: In the context of EVS codec for Narrowband (NB) signals, the handling of the hangover period after three consecutive active primary SAD decisions involves adjusting the threshold. Specifically, during this 8-frame window, the threshold is dynamically decreased (by either 5.2 or 2, depending on conditions) before making the final SAD decision by comparing it to the average SNR. This approach allows for a more nuanced handling of signal activity during the hangover period, reflecting the complexities of real-world telecom signal processing where static thresholds may not suffice.