Packet loss concealment tests

# What does it do?

These tests run a speech file through the packet loss concealment routines. The loss rate, in percent, and the packet size, in samples, may be specified on the command line.

# How are the tests run?

These tests process a speech file called pre_plc.wav. This file should contain 8000 sample/second 16 bits/sample linear audio. The tests read this file in blocks, of a size specified on the command line. Some of these blocks are dropped, to simulate packet loss. The rate of loss is also specified on the command line. The PLC module is then used to reconstruct an acceptable approximation to the original signal. The resulting audio is written to a new audio file, called post_plc.wav. This file contains 8000 sample/second 16 bits/sample linear audio.