## FLACCL: CUDA-enabled FLAC encoder by Gregory S. Chudov (prev. FlaCuda)

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Reply #65 –

I must add, that when computations are done in double precision, lls coeffs do not depend much on the scale of the signal, so the algorithm works, despite non-linear scaling of intermediate values.

But in single precision they start to drift much more. Which is wierd, because in literature Cholesky decomposition is said to be more stable than Levinson-Durbin recursion, with regard to rounding errors.

Here is a sample of this drift in double precision:

SCALE: 1.0/6 COEFF[31,0..2]: 0.523100 0.287037 0.204438; COVAR[31,0..2]: 43226.383239 170398.007602 -241511.245261

SCALE: 1.0/7 COEFF[31,0..2]: 0.523086 0.287057 0.204432; COVAR[31,0..2]: 37051.186185 146055.437263 -207009.641880