Revert "Revert "avoid quantize error variance. （幾何分布のエントロピー基準では、却って悪化）""

This reverts commit 0c272ca.
aikiriao · Jul 28, 2024 · a17cff4 · a17cff4
1 parent 2d45198
commit a17cff4
Showing 1 changed file with 1 addition and 5 deletions.
diff --git a/libs/srla_encoder/src/srla_encoder.c b/libs/srla_encoder/src/srla_encoder.c
@@ -939,13 +939,9 @@ static SRLAError SRLAEncoder_SelectBestLPCOrder(
         uint32_t order, tmp_best_order = 0;
         double len, mabse, minlen = FLT_MAX;
 
-        /* 次数あたり係数量子化誤差分散 */
-        const double qerr_var_unit = pow(2.0, -2.0 * SRLA_LPC_COEFFICIENT_BITWIDTH) * error_vars[0] / 12.0;
         for (order = 1; order <= max_coef_order; order++) {
-            /* 係数量子化誤差分散を加えた誤差分散 */
-            const double err_var = error_vars[order] + order * qerr_var_unit;
             /* Laplace分布の仮定で残差分散から平均絶対値を推定 */
-            mabse = 2.0 * sqrt(err_var / 2.0); /* 符号化で非負整数化するため2倍 */
+            mabse = 2.0 * sqrt(error_vars[order] / 2.0); /* 符号化で非負整数化するため2倍 */
             /* 残差符号のサイズ */
             len = SRLAEncoder_CalculateGeometricDistributionEntropy(mabse, header->bits_per_sample) * num_samples;
             /* 係数のサイズ */