Rename the bsinc resampler to bsinc12

1 files changed, 48 insertions, 46 deletions

diff --git a/utils/bsincgen.c b/utils/bsincgen.c
index 15813e36..0064060f 100644
--- a/utils/bsincgen.c
+++ b/utils/bsincgen.c
@@ -239,31 +239,50 @@ static void BsiGenerateTables(const char *tabname, const double rejection, const
     for(si = 0; si < BSINC_SCALE_COUNT; si++)

         mt[si] = (mt[si]+3) & ~3;

 

+    fprintf(stdout,

+"/* This %d%s order filter has a rejection of -%.0fdB, yielding a transition width\n"

+" * of ~%.3f (normalized frequency). Order increases when downsampling to a\n"

+" * limit of one octave, after which the quality of the filter (transition\n"

+" * width) suffers to reduce the CPU cost. The bandlimiting will cut all sound\n"

+" * after downsampling by ~%.2f octaves.\n"

+" */\n"

+"static const BSincTable %s = {\n",

+            order, (((order%100)/10) == 1) ? "th" :

+                   ((order%10) == 1) ? "st" :

+                   ((order%10) == 2) ? "nd" :

+                   ((order%10) == 3) ? "rd" : "th",

+            rejection, width, log2(1.0/scaleBase), tabname);

+

+    /* The scaleBase is calculated from the Kaiser window transition width.

+       It represents the absolute limit to the filter before it fully cuts

+       the signal.  The limit in octaves can be calculated by taking the

+       base-2 logarithm of its inverse: log_2(1 / scaleBase)

+    */

+    fprintf(stdout, "    /* scaleBase */ %.9ef, /* scaleRange */ %.9ef,\n", scaleBase, 1.0 / scaleRange);

+

+    fprintf(stdout, "    /* m */ {");

+    fprintf(stdout, " %d", mt[0]);

+    for(si = 1; si < BSINC_SCALE_COUNT; si++)

+        fprintf(stdout, ", %d", mt[si]);

+    fprintf(stdout, " },\n");

+

+    fprintf(stdout, "    /* filterOffset */ {");

+    fprintf(stdout, " %d", 0);

+    i = mt[0]*4*BSINC_PHASE_COUNT;

+    for(si = 1; si < BSINC_SCALE_COUNT; si++)

+    {

+        fprintf(stdout, ", %d", i);

+        i += mt[si]*4*BSINC_PHASE_COUNT;

+    }

+

+    fprintf(stdout, " },\n");

+

     // Calculate the table size.

     i = 0;

     for(si = 0; si < BSINC_SCALE_COUNT; si++)

         i += 4 * BSINC_PHASE_COUNT * mt[si];

 

-    fprintf(stdout, "/* Generated by bsincgen, do not edit! */\n\n"

-"/* Table of windowed sinc coefficients and deltas.  This %d%s order filter\n"

-" * has a rejection of -%gdB, yielding a transition width of ~%.3f\n"

-" * (normalized frequency).  Order increases when downsampling to a limit of\n"

-" * one octave, after which the quality of the filter (transition width)\n"

-" * suffers to reduce the CPU cost.  The bandlimiting will cut all sound after\n"

-" * downsampling by ~%.2f octaves.\n"

-" */\n"

-"static const struct {\n"

-"    alignas(16) const float Tab[%d];\n"

-"    const float scaleBase, scaleRange;\n"

-"    const int m[BSINC_SCALE_COUNT];\n"

-"    const int filterOffset[BSINC_SCALE_COUNT];\n"

-"} %s = {\n", order, (((order%100)/10) == 1) ? "th" :

-                     ((order%10) == 1) ? "st" :

-                     ((order%10) == 2) ? "nd" :

-                     ((order%10) == 3) ? "rd" : "th",

-              rejection, width, log2(1.0/scaleBase), i, tabname);

-

-    fprintf(stdout, "    /* Tab */ {\n");

+    fprintf(stdout, "\n    /* Tab (%d entries) */ {\n", i);

     for(si = 0; si < BSINC_SCALE_COUNT; si++)

     {

         const int m = mt[si];

@@ -287,31 +306,7 @@ static void BsiGenerateTables(const char *tabname, const double rejection, const
             fprintf(stdout, "\n");

         }

     }

-    fprintf(stdout, "    },\n\n");

-

-    /* The scaleBase is calculated from the Kaiser window transition width.

-       It represents the absolute limit to the filter before it fully cuts

-       the signal.  The limit in octaves can be calculated by taking the

-       base-2 logarithm of its inverse: log_2(1 / scaleBase)

-    */

-    fprintf(stdout, "    /* scaleBase */ %.9ef, /* scaleRange */ %.9ef,\n", scaleBase, 1.0 / scaleRange);

-

-    fprintf(stdout, "    /* m */ {");

-    fprintf(stdout, " %d", mt[0]);

-    for(si = 1; si < BSINC_SCALE_COUNT; si++)

-        fprintf(stdout, ", %d", mt[si]);

-    fprintf(stdout, " },\n");

-

-    fprintf(stdout, "    /* filterOffset */ {");

-    fprintf(stdout, " %d", 0);

-    i = mt[0]*4*BSINC_PHASE_COUNT;

-    for(si = 1; si < BSINC_SCALE_COUNT; si++)

-    {

-        fprintf(stdout, ", %d", i);

-        i += mt[si]*4*BSINC_PHASE_COUNT;

-    }

-

-    fprintf(stdout, " }\n};\n\n");

+    fprintf(stdout, "    }\n};\n\n");

 }

 

 

@@ -358,8 +353,15 @@ static void Sinc4GenerateTables(const double rejection)
 

 int main(void)

 {

+    fprintf(stdout, "/* Generated by bsincgen, do not edit! */\n\n"

+"typedef struct BSincTable {\n"

+"    const float scaleBase, scaleRange;\n"

+"    const int m[BSINC_SCALE_COUNT];\n"

+"    const int filterOffset[BSINC_SCALE_COUNT];\n"

+"    alignas(16) const float Tab[];\n"

+"} BSincTable;\n\n");

     /* An 11th order filter with a -60dB drop at nyquist. */

-    BsiGenerateTables("bsinc", 60.0, 11);

+    BsiGenerateTables("bsinc12", 60.0, 11);

     Sinc4GenerateTables(60.0);

     return 0;

 }