Merge pull request #12 from EdFuentetaja/master

Fixed random number generation that assumed that RAND_MAX == 2147483647.
szechyjs · Apr 30, 2014 · 1e343f4 · 1e343f4
2 parents fa0fed4 + fbe9d4e
commit 1e343f4
Showing 1 changed file with 28 additions and 9 deletions.
diff --git a/mbelib.c b/mbelib.c
@@ -22,6 +22,25 @@
 #include "mbelib.h"
 #include "mbelib_const.h"
 
+/**
+ * \return A pseudo-random float between [0.0, 1.0].
+ * See http://www.azillionmonkeys.com/qed/random.html for further improvements
+ */
+static float
+mbe_rand()
+{
+  return ((float) rand () / (float) RAND_MAX);
+}
+
+/**
+ * \return A pseudo-random float between [-pi, +pi].
+ */
+static float
+mbe_rand_phase()
+{
+  return mbe_rand() * (((float)M_PI) * 2.0F) - ((float)M_PI);
+}
+
 void
 mbe_printVersion (char *str)
 {
@@ -291,7 +310,7 @@ mbe_synthesizeSpeechf (float *aout_buf, mbe_parms * cur_mp, mbe_parms * prev_mp,
         }
       else
         {
-          cur_mp->PHIl[l] = cur_mp->PSIl[l] + ((numUv * ((((float) random () / (float) 2147483647) * M_PI * (float) 2) - M_PI)) / cur_mp->L);
+          cur_mp->PHIl[l] = cur_mp->PSIl[l] + ((numUv * mbe_rand_phase()) / cur_mp->L);
         }
     }
 
@@ -305,7 +324,7 @@ mbe_synthesizeSpeechf (float *aout_buf, mbe_parms * cur_mp, mbe_parms * prev_mp,
           // init random phase
           for (i = 0; i < uvquality; i++)
             {
-              rphase[i] = ((((float) random () / (float) 2147483647) * M_PI * (float) 2) - M_PI);
+              rphase[i] = mbe_rand_phase();
             }
           for (n = 0; n < N; n++)
             {
@@ -319,7 +338,7 @@ mbe_synthesizeSpeechf (float *aout_buf, mbe_parms * cur_mp, mbe_parms * prev_mp,
                   C3 = C3 + cosf ((cw0 * (float) n * ((float) l + ((float) i * uvstep) - uvoffset)) + rphase[i]);
                   if (cw0l > uvthreshold)
                     {
-                      C3 = C3 + ((cw0l - uvthreshold) * uvrand * ((float) random () / (float) 2147483647));
+                      C3 = C3 + ((cw0l - uvthreshold) * uvrand * mbe_rand());
                     }
                 }
               C3 = C3 * uvsine * Ws[n] * cur_mp->Ml[l] * qfactor;
@@ -333,7 +352,7 @@ mbe_synthesizeSpeechf (float *aout_buf, mbe_parms * cur_mp, mbe_parms * prev_mp,
           // init random phase
           for (i = 0; i < uvquality; i++)
             {
-              rphase[i] = ((((float) random () / (float) 2147483647) * M_PI * (float) 2) - M_PI);
+              rphase[i] = mbe_rand_phase();
             }
           for (n = 0; n < N; n++)
             {
@@ -347,7 +366,7 @@ mbe_synthesizeSpeechf (float *aout_buf, mbe_parms * cur_mp, mbe_parms * prev_mp,
                   C3 = C3 + cosf ((pw0 * (float) n * ((float) l + ((float) i * uvstep) - uvoffset)) + rphase[i]);
                   if (pw0l > uvthreshold)
                     {
-                      C3 = C3 + ((pw0l - uvthreshold) * uvrand * ((float) random () / (float) 2147483647));
+                      C3 = C3 + ((pw0l - uvthreshold) * uvrand * mbe_rand());
                     }
                 }
               C3 = C3 * uvsine * Ws[n + N] * prev_mp->Ml[l] * qfactor;
@@ -398,12 +417,12 @@ mbe_synthesizeSpeechf (float *aout_buf, mbe_parms * cur_mp, mbe_parms * prev_mp,
           // init random phase
           for (i = 0; i < uvquality; i++)
             {
-              rphase[i] = ((((float) random () / (float) 2147483647) * M_PI * (float) 2) - M_PI);
+              rphase[i] = mbe_rand_phase();
             }
           // init random phase
           for (i = 0; i < uvquality; i++)
             {
-              rphase2[i] = ((((float) random () / (float) 2147483647) * M_PI * (float) 2) - M_PI);
+              rphase2[i] = mbe_rand_phase();
             }
           for (n = 0; n < N; n++)
             {
@@ -414,7 +433,7 @@ mbe_synthesizeSpeechf (float *aout_buf, mbe_parms * cur_mp, mbe_parms * prev_mp,
                   C3 = C3 + cosf ((pw0 * (float) n * ((float) l + ((float) i * uvstep) - uvoffset)) + rphase[i]);
                   if (pw0l > uvthreshold)
                     {
-                      C3 = C3 + ((pw0l - uvthreshold) * uvrand * ((float) random () / (float) 2147483647));
+                      C3 = C3 + ((pw0l - uvthreshold) * uvrand * mbe_rand());
                     }
                 }
               C3 = C3 * uvsine * Ws[n + N] * prev_mp->Ml[l] * qfactor;
@@ -425,7 +444,7 @@ mbe_synthesizeSpeechf (float *aout_buf, mbe_parms * cur_mp, mbe_parms * prev_mp,
                   C4 = C4 + cosf ((cw0 * (float) n * ((float) l + ((float) i * uvstep) - uvoffset)) + rphase2[i]);
                   if (cw0l > uvthreshold)
                     {
-                      C4 = C4 + ((cw0l - uvthreshold) * uvrand * ((float) random () / (float) 2147483647));
+                      C4 = C4 + ((cw0l - uvthreshold) * uvrand * mbe_rand());
                     }
                 }
               C4 = C4 * uvsine * Ws[n] * cur_mp->Ml[l] * qfactor;