Question: In the EVS (Enhanced Voice Services) codec, as specified in standards, what is the primary difference between the adaptive post-filtering used here and the ITU-T G.729 post-processing?
Option 1: The number of filters in the cascade
Option 2: The sampling frequency at which it is performed (12.8 or 16 kHz)
Option 3: The inclusion of a tilt compensation filter
Option 4: The update rate of the post-filter coefficients
Explanation: The key distinction lies in the operating sampling frequency. While ITU-T G.729 operates at a standard telephony sampling rate (typically 8 kHz), EVS adaptive post-filtering is performed at higher rates of 12.8 or 16 kHz, enhancing its capability to handle wider bandwidth signals effectively.