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-rw-r--r--native-tools/bsincgen.c145
1 files changed, 72 insertions, 73 deletions
diff --git a/native-tools/bsincgen.c b/native-tools/bsincgen.c
index 72bd8183..7e7a1fa3 100644
--- a/native-tools/bsincgen.c
+++ b/native-tools/bsincgen.c
@@ -43,26 +43,22 @@
#ifndef M_PI
-#define M_PI (3.14159265358979323846)
+#define M_PI 3.14159265358979323846
#endif
#if !(defined(_ISOC99_SOURCE) || (defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE >= 200112L))
#define log2(x) (log(x) / log(2.0))
#endif
-/* Same as in alu.h! */
-#define FRACTIONBITS (12)
-#define FRACTIONONE (1<<FRACTIONBITS)
-
// The number of distinct scale and phase intervals within the filter table.
// Must be the same as in alu.h!
-#define BSINC_SCALE_COUNT (16)
-#define BSINC_PHASE_COUNT (16)
+#define BSINC_SCALE_COUNT 16
+#define BSINC_PHASE_COUNT 32
/* 48 points includes the doubling for downsampling, so the maximum number of
* base sample points is 24, which is 23rd order.
*/
-#define BSINC_POINTS_MAX (48)
+#define BSINC_POINTS_MAX 48
static double MinDouble(double a, double b)
{ return (a <= b) ? a : b; }
@@ -141,8 +137,8 @@ static double CalcKaiserBeta(const double rejection)
static void BsiGenerateTables(FILE *output, const char *tabname, const double rejection, const int order)
{
static double filter[BSINC_SCALE_COUNT][BSINC_PHASE_COUNT + 1][BSINC_POINTS_MAX];
- static double scDeltas[BSINC_SCALE_COUNT][BSINC_PHASE_COUNT ][BSINC_POINTS_MAX];
static double phDeltas[BSINC_SCALE_COUNT][BSINC_PHASE_COUNT + 1][BSINC_POINTS_MAX];
+ static double scDeltas[BSINC_SCALE_COUNT][BSINC_PHASE_COUNT ][BSINC_POINTS_MAX];
static double spDeltas[BSINC_SCALE_COUNT][BSINC_PHASE_COUNT ][BSINC_POINTS_MAX];
static int mt[BSINC_SCALE_COUNT];
static double at[BSINC_SCALE_COUNT];
@@ -151,8 +147,8 @@ static void BsiGenerateTables(FILE *output, const char *tabname, const double re
int si, pi, i;
memset(filter, 0, sizeof(filter));
- memset(scDeltas, 0, sizeof(scDeltas));
memset(phDeltas, 0, sizeof(phDeltas));
+ memset(scDeltas, 0, sizeof(scDeltas));
memset(spDeltas, 0, sizeof(spDeltas));
/* Calculate windowing parameters. The width describes the transition
@@ -176,8 +172,8 @@ static void BsiGenerateTables(FILE *output, const char *tabname, const double re
}
/* Calculate the Kaiser-windowed Sinc filter coefficients for each scale
- and phase.
- */
+ * and phase.
+ */
for(si = 0; si < BSINC_SCALE_COUNT; si++)
{
const int m = mt[si];
@@ -199,13 +195,10 @@ static void BsiGenerateTables(FILE *output, const char *tabname, const double re
}
}
- /* Linear interpolation between scales is simplified by pre-calculating
- the delta (b - a) in: x = a + f (b - a)
-
- Given a difference in points between scales, the destination points
- will be 0, thus: x = a + f (-a)
- */
- for(si = 0; si < (BSINC_SCALE_COUNT - 1); si++)
+ /* Linear interpolation between phases is simplified by pre-calculating the
+ * delta (b - a) in: x = a + f (b - a)
+ */
+ for(si = 0; si < BSINC_SCALE_COUNT; si++)
{
const int m = mt[si];
const int o = num_points_min - (m / 2);
@@ -213,12 +206,16 @@ static void BsiGenerateTables(FILE *output, const char *tabname, const double re
for(pi = 0; pi < BSINC_PHASE_COUNT; pi++)
{
for(i = 0; i < m; i++)
- scDeltas[si][pi][o + i] = filter[si + 1][pi][o + i] - filter[si][pi][o + i];
+ phDeltas[si][pi][o + i] = filter[si][pi + 1][o + i] - filter[si][pi][o + i];
}
}
- // Linear interpolation between phases is also simplified.
- for(si = 0; si < BSINC_SCALE_COUNT; si++)
+ /* Linear interpolation between scales is also simplified.
+ *
+ * Given a difference in points between scales, the destination points will
+ * be 0, thus: x = a + f (-a)
+ */
+ for(si = 0; si < (BSINC_SCALE_COUNT - 1); si++)
{
const int m = mt[si];
const int o = num_points_min - (m / 2);
@@ -226,13 +223,13 @@ static void BsiGenerateTables(FILE *output, const char *tabname, const double re
for(pi = 0; pi < BSINC_PHASE_COUNT; pi++)
{
for(i = 0; i < m; i++)
- phDeltas[si][pi][o + i] = filter[si][pi + 1][o + i] - filter[si][pi][o + i];
+ scDeltas[si][pi][o + i] = filter[si + 1][pi][o + i] - filter[si][pi][o + i];
}
}
/* This last simplification is done to complete the bilinear equation for
- the combination of scale and phase.
- */
+ * the combination of phase and scale.
+ */
for(si = 0; si < (BSINC_SCALE_COUNT - 1); si++)
{
const int m = mt[si];
@@ -245,10 +242,15 @@ static void BsiGenerateTables(FILE *output, const char *tabname, const double re
}
}
- // Make sure the number of points is a multiple of 4 (for SIMD).
+ /* Make sure the number of points is a multiple of 4 (for SIMD). */
for(si = 0; si < BSINC_SCALE_COUNT; si++)
mt[si] = (mt[si]+3) & ~3;
+ /* Calculate the table size. */
+ i = 0;
+ for(si = 0; si < BSINC_SCALE_COUNT; si++)
+ i += 4 * BSINC_PHASE_COUNT * mt[si];
+
fprintf(output,
"/* 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"
@@ -256,12 +258,36 @@ static void BsiGenerateTables(FILE *output, const char *tabname, const double re
" * width) suffers to reduce the CPU cost. The bandlimiting will cut all sound\n"
" * after downsampling by ~%.2f octaves.\n"
" */\n"
-"const BSincTable %s = {\n",
+"alignas(16) constexpr float %s_tab[%d] = {\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);
+ rejection, width, log2(1.0/scaleBase), tabname, i);
+ for(si = 0; si < BSINC_SCALE_COUNT; si++)
+ {
+ const int m = mt[si];
+ const int o = num_points_min - (m / 2);
+
+ for(pi = 0; pi < BSINC_PHASE_COUNT; pi++)
+ {
+ fprintf(output, " /* %2d,%2d (%d) */", si, pi, m);
+ fprintf(output, "\n ");
+ for(i = 0; i < m; i++)
+ fprintf(output, " %+14.9ef,", filter[si][pi][o + i]);
+ fprintf(output, "\n ");
+ for(i = 0; i < m; i++)
+ fprintf(output, " %+14.9ef,", phDeltas[si][pi][o + i]);
+ fprintf(output, "\n ");
+ for(i = 0; i < m; i++)
+ fprintf(output, " %+14.9ef,", scDeltas[si][pi][o + i]);
+ fprintf(output, "\n ");
+ for(i = 0; i < m; i++)
+ fprintf(output, " %+14.9ef,", spDeltas[si][pi][o + i]);
+ fprintf(output, "\n");
+ }
+ }
+ fprintf(output, "};\nconstexpr BSincTable %s = {\n", tabname);
/* The scaleBase is calculated from the Kaiser window transition width.
It represents the absolute limit to the filter before it fully cuts
@@ -271,52 +297,23 @@ static void BsiGenerateTables(FILE *output, const char *tabname, const double re
fprintf(output, " /* scaleBase */ %.9ef, /* scaleRange */ %.9ef,\n", scaleBase, 1.0 / scaleRange);
fprintf(output, " /* m */ {");
- fprintf(output, " %d", mt[0]);
+ fprintf(output, " %du", mt[0]);
for(si = 1; si < BSINC_SCALE_COUNT; si++)
- fprintf(output, ", %d", mt[si]);
+ fprintf(output, ", %du", mt[si]);
fprintf(output, " },\n");
fprintf(output, " /* filterOffset */ {");
- fprintf(output, " %d", 0);
+ fprintf(output, " %du", 0);
i = mt[0]*4*BSINC_PHASE_COUNT;
for(si = 1; si < BSINC_SCALE_COUNT; si++)
{
- fprintf(output, ", %d", i);
+ fprintf(output, ", %du", i);
i += mt[si]*4*BSINC_PHASE_COUNT;
}
fprintf(output, " },\n");
-
- // Calculate the table size.
- i = 0;
- for(si = 0; si < BSINC_SCALE_COUNT; si++)
- i += 4 * BSINC_PHASE_COUNT * mt[si];
-
- fprintf(output, "\n /* Tab (%d entries) */ {\n", i);
- for(si = 0; si < BSINC_SCALE_COUNT; si++)
- {
- const int m = mt[si];
- const int o = num_points_min - (m / 2);
-
- for(pi = 0; pi < BSINC_PHASE_COUNT; pi++)
- {
- fprintf(output, " /* %2d,%2d (%d) */", si, pi, m);
- fprintf(output, "\n ");
- for(i = 0; i < m; i++)
- fprintf(output, " %+14.9ef,", filter[si][pi][o + i]);
- fprintf(output, "\n ");
- for(i = 0; i < m; i++)
- fprintf(output, " %+14.9ef,", scDeltas[si][pi][o + i]);
- fprintf(output, "\n ");
- for(i = 0; i < m; i++)
- fprintf(output, " %+14.9ef,", phDeltas[si][pi][o + i]);
- fprintf(output, "\n ");
- for(i = 0; i < m; i++)
- fprintf(output, " %+14.9ef,", spDeltas[si][pi][o + i]);
- fprintf(output, "\n");
- }
- }
- fprintf(output, " }\n};\n\n");
+ fprintf(output, " %s_tab\n", tabname);
+ fprintf(output, "};\n\n");
}
@@ -344,21 +341,23 @@ int main(int argc, char *argv[])
else
output = stdout;
- fprintf(output, "/* Generated by bsincgen, do not edit! */\n\n"
+ fprintf(output, "/* Generated by bsincgen, do not edit! */\n"
+"#pragma once\n\n"
"static_assert(BSINC_SCALE_COUNT == %d, \"Unexpected BSINC_SCALE_COUNT value!\");\n"
-"static_assert(BSINC_PHASE_COUNT == %d, \"Unexpected BSINC_PHASE_COUNT value!\");\n"
-"static_assert(FRACTIONONE == %d, \"Unexpected FRACTIONONE value!\");\n\n"
-"typedef struct BSincTable {\n"
+"static_assert(BSINC_PHASE_COUNT == %d, \"Unexpected BSINC_PHASE_COUNT value!\");\n\n"
+"namespace {\n\n"
+"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", BSINC_SCALE_COUNT, BSINC_PHASE_COUNT, FRACTIONONE);
+" const unsigned int m[BSINC_SCALE_COUNT];\n"
+" const unsigned int filterOffset[BSINC_SCALE_COUNT];\n"
+" const float *Tab;\n"
+"};\n\n", BSINC_SCALE_COUNT, BSINC_PHASE_COUNT);
/* A 23rd order filter with a -60dB drop at nyquist. */
BsiGenerateTables(output, "bsinc24", 60.0, 23);
- /* An 11th order filter with a -40dB drop at nyquist. */
- BsiGenerateTables(output, "bsinc12", 40.0, 11);
+ /* An 11th order filter with a -60dB drop at nyquist. */
+ BsiGenerateTables(output, "bsinc12", 60.0, 11);
+ fprintf(output, "} // namespace\n");
if(output != stdout)
fclose(output);
output = NULL;
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-01 11:40:06 +0000