add resampler

git-svn-id: file:///home/lennart/svn/public/pulseaudio/trunk@44 fefdeb5f-60dc-0310-8127-8f9354f1896f

1 files changed, 99 insertions, 0 deletions

diff --git a/src/sconv.c b/src/sconv.c
new file mode 100644
index 00000000..11438b41
--- /dev/null
+++ b/src/sconv.c
@@ -0,0 +1,99 @@
+#include <stdlib.h>
+#include <assert.h>
+#include "endianmacros.h"
+#include "sconv.h"
+
+static void s16le_to_float32(unsigned n, const void *a, unsigned an, float *b) {
+    const int16_t *ca = a;
+    assert(n && a && an && b);
+
+    for (; n > 0; n--) {
+        unsigned i;
+        float sum = 0;
+        
+        for (i = 0; i < an; i++) {
+            int16_t s = *(ca++);
+            sum += ((float) INT16_FROM_LE(s))/0x7FFF;
+        }
+
+        if (sum > 1)
+            sum = 1;
+        if (sum < -1)
+            sum = -1;
+        
+        *(b++) = sum;
+    }
+}
+
+static void s16le_from_float32(unsigned n, const float *a, void *b, unsigned bn) {
+    int16_t *cb = b;
+    assert(n && a && b && bn);
+    
+    for (; n > 0; n--) {
+        unsigned i;
+        int16_t s;
+        float v = *(a++);
+
+        if (v > 1)
+            v = 1;
+        if (v < -1)
+            v = -1;
+        
+        s = (int16_t) (v * 0x7FFF);
+
+        for (i = 0; i < bn; i++)
+            *(cb++) = INT16_TO_LE(v);
+    }
+}
+
+static void float32_to_float32(unsigned n, const void *a, unsigned an, float *b) {
+    unsigned i;
+    const float *ca = a;
+    assert(n && a && an && b);
+    for (; n > 0; n--) {
+        float sum = 0;
+
+        for (i = 0; i < an; i++)
+            sum += *(ca++);
+
+        if (sum > 1)
+            sum = 1;
+        if (sum < -1)
+            sum = -1;
+
+        *(b++) = sum;
+    }
+}
+
+static void float32_from_float32(unsigned n, const float *a, void *b, unsigned bn) {
+    unsigned i;
+    float *cb = b;
+    assert(n && a && b && bn);
+    for (; n > 0; n--) {
+        float v = *(a++);
+        for (i = 0; i < bn; i++)
+            *(cb++) = v;
+    }
+}
+
+convert_to_float32_func_t get_convert_to_float32_function(enum pa_sample_format f) {
+    switch(f) {
+        case PA_SAMPLE_S16LE:
+            return s16le_to_float32;
+        case PA_SAMPLE_FLOAT32:
+            return float32_to_float32;
+        default:
+            return NULL;
+    }
+}
+
+convert_from_float32_func_t get_convert_from_float32_function(enum pa_sample_format f) {
+    switch(f) {
+        case PA_SAMPLE_S16LE:
+            return s16le_from_float32;
+        case PA_SAMPLE_FLOAT32:
+            return float32_from_float32;
+        default:
+            return NULL;
+    }
+}