resample: split linear into its own function

libavresample/resample.c

@@ -181,22 +181,22 @@ ResampleContext *ff_audio_resample_init(AVAudioResampleContext *avr)
 
     switch (avr->internal_sample_fmt) {
     case AV_SAMPLE_FMT_DBLP:
-        c->resample_one  = resample_one_dbl;
+        c->resample_one  = c->linear ? resample_linear_dbl : resample_one_dbl;
         c->resample_nearest = resample_nearest_dbl;
         c->set_filter    = set_filter_dbl;
         break;
     case AV_SAMPLE_FMT_FLTP:
-        c->resample_one  = resample_one_flt;
+        c->resample_one  = c->linear ? resample_linear_flt : resample_one_flt;
         c->resample_nearest = resample_nearest_flt;
         c->set_filter    = set_filter_flt;
         break;
     case AV_SAMPLE_FMT_S32P:
-        c->resample_one  = resample_one_s32;
+        c->resample_one  = c->linear ? resample_linear_s32 : resample_one_s32;
         c->resample_nearest = resample_nearest_s32;
         c->set_filter    = set_filter_s32;
         break;
     case AV_SAMPLE_FMT_S16P:
-        c->resample_one  = resample_one_s16;
+        c->resample_one  = c->linear ? resample_linear_s16 : resample_one_s16;
         c->resample_nearest = resample_nearest_s16;
         c->set_filter    = set_filter_s16;
         break;

libavresample/resample_template.c

@@ -61,6 +61,27 @@ static void SET_TYPE(resample_nearest)(void *dst0, int dst_index, const void *sr
     dst[dst_index] = src[index];
 }
 
+static void SET_TYPE(resample_linear)(ResampleContext *c, void *dst0, int dst_index,
+                                      const void *src0, unsigned int index, int frac)
+{
+    FELEM *dst = dst0;
+    const FELEM *src = src0;
+    int i;
+    unsigned int sample_index = index >> c->phase_shift;
+    FELEM2 val = 0;
+    FELEM *filter = ((FELEM *)c->filter_bank) +
+                    c->filter_length * (index & c->phase_mask);
+    FELEM2 v2 = 0;
+
+    for (i = 0; i < c->filter_length; i++) {
+        val += src[sample_index + i] * (FELEM2)filter[i];
+        v2  += src[sample_index + i] * (FELEM2)filter[i + c->filter_length];
+    }
+    val += (v2 - val) * (FELEML)frac / c->src_incr;
+
+    OUT(dst[dst_index], val);
+}
+
 static void SET_TYPE(resample_one)(ResampleContext *c,
                                    void *dst0, int dst_index, const void *src0,
                                    unsigned int index, int frac)
@@ -73,17 +94,8 @@ static void SET_TYPE(resample_one)(ResampleContext *c,
     FELEM *filter = ((FELEM *)c->filter_bank) +
                     c->filter_length * (index & c->phase_mask);
 
-    if (c->linear) {
-        FELEM2 v2 = 0;
-        for (i = 0; i < c->filter_length; i++) {
-            val += src[sample_index + i] * (FELEM2)filter[i];
-            v2  += src[sample_index + i] * (FELEM2)filter[i + c->filter_length];
-        }
-        val += (v2 - val) * (FELEML)frac / c->src_incr;
-    } else {
-        for (i = 0; i < c->filter_length; i++)
-            val += src[sample_index + i] * (FELEM2)filter[i];
-    }
+    for (i = 0; i < c->filter_length; i++)
+        val += src[sample_index + i] * (FELEM2)filter[i];
 
     OUT(dst[dst_index], val);
 }