#define PHASE_SHIFT 10
#define PHASE_COUNT (1<<PHASE_SHIFT)
#define PHASE_MASK (PHASE_COUNT-1)
+#define FILTER_SIZE 16
+//#define LINEAR 1
+
+#if 1
#define FILTER_SHIFT 15
+#define FELEM int16_t
+#define FELEM2 int32_t
+#define FELEM_MAX INT16_MAX
+#define FELEM_MIN INT16_MIN
+#else
+#define FILTER_SHIFT 24
+
+#define FELEM int32_t
+#define FELEM2 int64_t
+#define FELEM_MAX INT32_MAX
+#define FELEM_MIN INT32_MIN
+#endif
+
+
typedef struct AVResampleContext{
- short *filter_bank;
+ FELEM *filter_bank;
int filter_length;
int ideal_dst_incr;
int dst_incr;
* @param scale wanted sum of coefficients for each filter
* @param type 0->cubic, 1->blackman nuttall windowed sinc, 2->kaiser windowed sinc beta=16
*/
-void av_build_filter(int16_t *filter, double factor, int tap_count, int phase_count, int scale, int type){
+void av_build_filter(FELEM *filter, double factor, int tap_count, int phase_count, int scale, int type){
int ph, i, v;
double x, y, w, tab[tap_count];
const int center= (tap_count-1)/2;
/* normalize so that an uniform color remains the same */
for(i=0;i<tap_count;i++) {
- v = clip(lrintf(tab[i] * scale / norm + e), -32768, 32767);
+ v = clip(lrintf(tab[i] * scale / norm + e), FELEM_MIN, FELEM_MAX);
filter[ph * tap_count + i] = v;
e += tab[i] * scale / norm - v;
}
memset(c, 0, sizeof(AVResampleContext));
- c->filter_length= ceil(16.0/factor);
- c->filter_bank= av_mallocz(c->filter_length*(PHASE_COUNT+1)*sizeof(short));
+ c->filter_length= ceil(FILTER_SIZE/factor);
+ c->filter_bank= av_mallocz(c->filter_length*(PHASE_COUNT+1)*sizeof(FELEM));
av_build_filter(c->filter_bank, factor, c->filter_length, PHASE_COUNT, 1<<FILTER_SHIFT, 1);
- memcpy(&c->filter_bank[c->filter_length*PHASE_COUNT+1], c->filter_bank, (c->filter_length-1)*sizeof(short));
+ memcpy(&c->filter_bank[c->filter_length*PHASE_COUNT+1], c->filter_bank, (c->filter_length-1)*sizeof(FELEM));
c->filter_bank[c->filter_length*PHASE_COUNT]= c->filter_bank[c->filter_length - 1];
c->src_incr= out_rate;
int compensation_distance= c->compensation_distance;
for(dst_index=0; dst_index < dst_size; dst_index++){
- short *filter= c->filter_bank + c->filter_length*(index & PHASE_MASK);
+ FELEM *filter= c->filter_bank + c->filter_length*(index & PHASE_MASK);
int sample_index= index >> PHASE_SHIFT;
- int val=0;
+ FELEM2 val=0;
if(sample_index < 0){
for(i=0; i<c->filter_length; i++)
}else if(sample_index + c->filter_length > src_size){
break;
}else{
-#if 0
+#ifdef LINEAR
int64_t v=0;
int sub_phase= (frac<<12) / c->src_incr;
for(i=0; i<c->filter_length; i++){
- int64_t coeff= filter[i]*(4096 - sub_phase) + filter[i + c->filter_length]*sub_phase;
+ int64_t coeff= filter[i]*(FELEM2)(4096 - sub_phase) + filter[i + c->filter_length]*(FELEM2)sub_phase;
v += src[sample_index + i] * coeff;
}
val= v>>12;
#else
for(i=0; i<c->filter_length; i++){
- val += src[sample_index + i] * filter[i];
+ val += src[sample_index + i] * (FELEM2)filter[i];
}
#endif
}