Merge commit 'cb45553f577f8e0ebfe05d3287e1b6fa5859b967'
[ffmpeg.git] / libavcodec / iirfilter.c
index 832559c..610add1 100644 (file)
@@ -26,6 +26,7 @@
 
 #include "iirfilter.h"
 #include <math.h>
+#include "libavutil/common.h"
 
 /**
  * IIR filter global parameters
@@ -137,22 +138,20 @@ static int biquad_init_coeffs(void *avc, struct FFIIRFilterCoeffs *c,
 
     if (filt_mode == FF_FILTER_MODE_HIGHPASS) {
         c->gain  =  ((1.0 + cos_w0) / 2.0)  / a0;
-        x0       = (-(1.0 + cos_w0))        / a0;
-        x1       =  ((1.0 + cos_w0) / 2.0)  / a0;
+        x0       =  ((1.0 + cos_w0) / 2.0)  / a0;
+        x1       = (-(1.0 + cos_w0))        / a0;
     } else { // FF_FILTER_MODE_LOWPASS
         c->gain  =  ((1.0 - cos_w0) / 2.0)  / a0;
-        x0       =   (1.0 - cos_w0)         / a0;
-        x1       =  ((1.0 - cos_w0) / 2.0)  / a0;
+        x0       =  ((1.0 - cos_w0) / 2.0)  / a0;
+        x1       =   (1.0 - cos_w0)         / a0;
     }
-    c->cy[0] =  (2.0 *  cos_w0)        / a0;
-    c->cy[1] = (-1.0 + (sin_w0 / 2.0)) / a0;
+    c->cy[0] = (-1.0 + (sin_w0 / 2.0)) / a0;
+    c->cy[1] =  (2.0 *  cos_w0)        / a0;
 
     // divide by gain to make the x coeffs integers.
     // during filtering, the delay state will include the gain multiplication
     c->cx[0] = lrintf(x0 / c->gain);
     c->cx[1] = lrintf(x1 / c->gain);
-    c->cy[0] /= c->gain;
-    c->cy[1] /= c->gain;
 
     return 0;
 }
@@ -256,11 +255,29 @@ av_cold struct FFIIRFilterState* ff_iir_filter_init_state(int order)
     }                                                                       \
 }
 
+#define FILTER_O2(type, fmt) {                                              \
+    int i;                                                                  \
+    const type *src0 = src;                                                 \
+    type       *dst0 = dst;                                                 \
+    for (i = 0; i < size; i++) {                                            \
+        float in = *src0   * c->gain  +                                     \
+                   s->x[0] * c->cy[0] +                                     \
+                   s->x[1] * c->cy[1];                                      \
+        CONV_##fmt(*dst0, s->x[0] + in + s->x[1] * c->cx[1])                \
+        s->x[0] = s->x[1];                                                  \
+        s->x[1] = in;                                                       \
+        src0 += sstep;                                                      \
+        dst0 += dstep;                                                      \
+    }                                                                       \
+}
+
 void ff_iir_filter(const struct FFIIRFilterCoeffs *c,
                    struct FFIIRFilterState *s, int size,
                    const int16_t *src, int sstep, int16_t *dst, int dstep)
 {
-    if (c->order == 4) {
+    if (c->order == 2) {
+        FILTER_O2(int16_t, S16)
+    } else if (c->order == 4) {
         FILTER_BW_O4(int16_t, S16)
     } else {
         FILTER_DIRECT_FORM_II(int16_t, S16)
@@ -271,7 +288,9 @@ void ff_iir_filter_flt(const struct FFIIRFilterCoeffs *c,
                        struct FFIIRFilterState *s, int size,
                        const float *src, int sstep, float *dst, int dstep)
 {
-    if (c->order == 4) {
+    if (c->order == 2) {
+        FILTER_O2(float, FLT)
+    } else if (c->order == 4) {
         FILTER_BW_O4(float, FLT)
     } else {
         FILTER_DIRECT_FORM_II(float, FLT)
@@ -293,6 +312,8 @@ av_cold void ff_iir_filter_free_coeffs(struct FFIIRFilterCoeffs *coeffs)
 }
 
 #ifdef TEST
+#include <stdio.h>
+
 #define FILT_ORDER 4
 #define SIZE 1024
 int main(void)
@@ -302,9 +323,8 @@ int main(void)
     float cutoff_coeff = 0.4;
     int16_t x[SIZE], y[SIZE];
     int i;
-    FILE* fd;
 
-    fcoeffs = ff_iir_filter_init_coeffs(FF_FILTER_TYPE_BUTTERWORTH,
+    fcoeffs = ff_iir_filter_init_coeffs(NULL, FF_FILTER_TYPE_BUTTERWORTH,
                                         FF_FILTER_MODE_LOWPASS, FILT_ORDER,
                                         cutoff_coeff, 0.0, 0.0);
     fstate  = ff_iir_filter_init_state(FILT_ORDER);
@@ -315,13 +335,8 @@ int main(void)
 
     ff_iir_filter(fcoeffs, fstate, SIZE, x, 1, y, 1);
 
-    fd = fopen("in.bin", "w");
-    fwrite(x, sizeof(x[0]), SIZE, fd);
-    fclose(fd);
-
-    fd = fopen("out.bin", "w");
-    fwrite(y, sizeof(y[0]), SIZE, fd);
-    fclose(fd);
+    for (i = 0; i < SIZE; i++)
+        printf("%6d %6d\n", x[i], y[i]);
 
     ff_iir_filter_free_coeffs(fcoeffs);
     ff_iir_filter_free_state(fstate);