Item generation: Incomplete convolution with IRs

As audio sources are trimmed, the convolution with IRs using reverb.exe is suddenly cut without letting the filter ring out.

In accordance with IVAS-7a, the time offset for the second sentence shall be: Y = X + length(raw mono sentence 1) + GAP, which means the IR will ring out within the GAP for the first sentence. Further Z zeros shall be appended resulting in a sample of length X + length(raw mono sentence 1) + GAP + length(filtered sentence 2) + Z, where length(filtered sentence 2) = length(raw mono sentence 2) + length(IR)-1. This means the filter should ring out and then Z zeros are appended.

X = 500 ms Z = 1000 ms