streamline the residual energy calculation

diff --git a/src/libFLAC/fixed.c b/src/libFLAC/fixed.c
index 1fb3f06..f1d7675 100644 (file)
--- a/src/libFLAC/fixed.c
+++ b/src/libFLAC/fixed.c
@@ -65,11 +65,19 @@ unsigned FLAC__fixed_compute_best_predictor(const FLAC__int32 data[], unsigned d
        else
                order = 4;
 
-       residual_bits_per_sample[0] = (FLAC__real)((data_len > 0 && total_error_0 > 0) ? log(M_LN2 * (double)total_error_0 / (double) data_len) / M_LN2 : 0.0);
-       residual_bits_per_sample[1] = (FLAC__real)((data_len > 0 && total_error_1 > 0) ? log(M_LN2 * (double)total_error_1 / (double) data_len) / M_LN2 : 0.0);
-       residual_bits_per_sample[2] = (FLAC__real)((data_len > 0 && total_error_2 > 0) ? log(M_LN2 * (double)total_error_2 / (double) data_len) / M_LN2 : 0.0);
-       residual_bits_per_sample[3] = (FLAC__real)((data_len > 0 && total_error_3 > 0) ? log(M_LN2 * (double)total_error_3 / (double) data_len) / M_LN2 : 0.0);
-       residual_bits_per_sample[4] = (FLAC__real)((data_len > 0 && total_error_4 > 0) ? log(M_LN2 * (double)total_error_4 / (double) data_len) / M_LN2 : 0.0);
+       /* Estimate the expected number of bits per residual signal sample. */
+       /* 'total_error*' is linearly related to the variance of the residual */
+       /* signal, so we use it directly to compute E(|x|) */
+       FLAC__ASSERT(data_len > 0 || total_error_0 == 0);
+       FLAC__ASSERT(data_len > 0 || total_error_1 == 0);
+       FLAC__ASSERT(data_len > 0 || total_error_2 == 0);
+       FLAC__ASSERT(data_len > 0 || total_error_3 == 0);
+       FLAC__ASSERT(data_len > 0 || total_error_4 == 0);
+       residual_bits_per_sample[0] = (FLAC__real)((total_error_0 > 0) ? log(M_LN2 * (double)total_error_0 / (double)data_len) / M_LN2 : 0.0);
+       residual_bits_per_sample[1] = (FLAC__real)((total_error_1 > 0) ? log(M_LN2 * (double)total_error_1 / (double)data_len) / M_LN2 : 0.0);
+       residual_bits_per_sample[2] = (FLAC__real)((total_error_2 > 0) ? log(M_LN2 * (double)total_error_2 / (double)data_len) / M_LN2 : 0.0);
+       residual_bits_per_sample[3] = (FLAC__real)((total_error_3 > 0) ? log(M_LN2 * (double)total_error_3 / (double)data_len) / M_LN2 : 0.0);
+       residual_bits_per_sample[4] = (FLAC__real)((total_error_4 > 0) ? log(M_LN2 * (double)total_error_4 / (double)data_len) / M_LN2 : 0.0);
 
        return order;
 }
@@ -110,19 +118,24 @@ unsigned FLAC__fixed_compute_best_predictor_wide(const FLAC__int32 data[], unsig
        /* Estimate the expected number of bits per residual signal sample. */
        /* 'total_error*' is linearly related to the variance of the residual */
        /* signal, so we use it directly to compute E(|x|) */
+       FLAC__ASSERT(data_len > 0 || total_error_0 == 0);
+       FLAC__ASSERT(data_len > 0 || total_error_1 == 0);
+       FLAC__ASSERT(data_len > 0 || total_error_2 == 0);
+       FLAC__ASSERT(data_len > 0 || total_error_3 == 0);
+       FLAC__ASSERT(data_len > 0 || total_error_4 == 0);
 #if defined _MSC_VER || defined __MINGW32__
        /* with VC++ you have to spoon feed it the casting */
-       residual_bits_per_sample[0] = (FLAC__real)((data_len > 0 && total_error_0 > 0) ? log(M_LN2 * (double)(FLAC__int64)total_error_0 / (double) data_len) / M_LN2 : 0.0);
-       residual_bits_per_sample[1] = (FLAC__real)((data_len > 0 && total_error_1 > 0) ? log(M_LN2 * (double)(FLAC__int64)total_error_1 / (double) data_len) / M_LN2 : 0.0);
-       residual_bits_per_sample[2] = (FLAC__real)((data_len > 0 && total_error_2 > 0) ? log(M_LN2 * (double)(FLAC__int64)total_error_2 / (double) data_len) / M_LN2 : 0.0);
-       residual_bits_per_sample[3] = (FLAC__real)((data_len > 0 && total_error_3 > 0) ? log(M_LN2 * (double)(FLAC__int64)total_error_3 / (double) data_len) / M_LN2 : 0.0);
-       residual_bits_per_sample[4] = (FLAC__real)((data_len > 0 && total_error_4 > 0) ? log(M_LN2 * (double)(FLAC__int64)total_error_4 / (double) data_len) / M_LN2 : 0.0);
+       residual_bits_per_sample[0] = (FLAC__real)((total_error_0 > 0) ? log(M_LN2 * (double)(FLAC__int64)total_error_0 / (double)data_len) / M_LN2 : 0.0);
+       residual_bits_per_sample[1] = (FLAC__real)((total_error_1 > 0) ? log(M_LN2 * (double)(FLAC__int64)total_error_1 / (double)data_len) / M_LN2 : 0.0);
+       residual_bits_per_sample[2] = (FLAC__real)((total_error_2 > 0) ? log(M_LN2 * (double)(FLAC__int64)total_error_2 / (double)data_len) / M_LN2 : 0.0);
+       residual_bits_per_sample[3] = (FLAC__real)((total_error_3 > 0) ? log(M_LN2 * (double)(FLAC__int64)total_error_3 / (double)data_len) / M_LN2 : 0.0);
+       residual_bits_per_sample[4] = (FLAC__real)((total_error_4 > 0) ? log(M_LN2 * (double)(FLAC__int64)total_error_4 / (double)data_len) / M_LN2 : 0.0);
 #else
-       residual_bits_per_sample[0] = (FLAC__real)((data_len > 0 && total_error_0 > 0) ? log(M_LN2 * (double)total_error_0 / (double) data_len) / M_LN2 : 0.0);
-       residual_bits_per_sample[1] = (FLAC__real)((data_len > 0 && total_error_1 > 0) ? log(M_LN2 * (double)total_error_1 / (double) data_len) / M_LN2 : 0.0);
-       residual_bits_per_sample[2] = (FLAC__real)((data_len > 0 && total_error_2 > 0) ? log(M_LN2 * (double)total_error_2 / (double) data_len) / M_LN2 : 0.0);
-       residual_bits_per_sample[3] = (FLAC__real)((data_len > 0 && total_error_3 > 0) ? log(M_LN2 * (double)total_error_3 / (double) data_len) / M_LN2 : 0.0);
-       residual_bits_per_sample[4] = (FLAC__real)((data_len > 0 && total_error_4 > 0) ? log(M_LN2 * (double)total_error_4 / (double) data_len) / M_LN2 : 0.0);
+       residual_bits_per_sample[0] = (FLAC__real)((total_error_0 > 0) ? log(M_LN2 * (double)total_error_0 / (double)data_len) / M_LN2 : 0.0);
+       residual_bits_per_sample[1] = (FLAC__real)((total_error_1 > 0) ? log(M_LN2 * (double)total_error_1 / (double)data_len) / M_LN2 : 0.0);
+       residual_bits_per_sample[2] = (FLAC__real)((total_error_2 > 0) ? log(M_LN2 * (double)total_error_2 / (double)data_len) / M_LN2 : 0.0);
+       residual_bits_per_sample[3] = (FLAC__real)((total_error_3 > 0) ? log(M_LN2 * (double)total_error_3 / (double)data_len) / M_LN2 : 0.0);
+       residual_bits_per_sample[4] = (FLAC__real)((total_error_4 > 0) ? log(M_LN2 * (double)total_error_4 / (double)data_len) / M_LN2 : 0.0);
 #endif
 
        return order;