Reduce audio fragment alignment jitter by penalizing alignment
correction offsets that deviate too much from the target offset.
This is accomplished by multiplying the cross correlation search
window with a quadratic function.
Signed-off-by: NPavel Koshevoy <pavel@homestead.aragog.com>
Signed-off-by: NMichael Niedermayer <michaelni@gmx.at>

Add atempo audio filter for adjusting audio tempo without affecting
pitch. This filter implements WSOLA algorithm with fast cross
correlation calculation in frequency domain.
Signed-off-by: NPavel Koshevoy <pavel@homestead.aragog.com>
Signed-off-by: NStefano Sabatini <stefasab@gmail.com>