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authorMichael Niedermayer <michaelni@gmx.at>2004-10-21 03:11:34 +0000
committerMichael Niedermayer <michaelni@gmx.at>2004-10-21 03:11:34 +0000
commited861c6bd24548f96019923c48b882e14070555d (patch)
tree4b4f409f576681c7faaacf74a61611ff246b65e7 /libavcodec/resample2.c
parentf25ba8b39380d3bbe1b58b6422062427d19b787c (diff)
downloadffmpeg-ed861c6bd24548f96019923c48b882e14070555d.tar.gz
make most resample filter parameters selectable at runtime
Originally committed as revision 3617 to svn://svn.ffmpeg.org/ffmpeg/trunk
Diffstat (limited to 'libavcodec/resample2.c')
-rw-r--r--libavcodec/resample2.c44
1 files changed, 22 insertions, 22 deletions
diff --git a/libavcodec/resample2.c b/libavcodec/resample2.c
index 22f787dc16..05b12a0df1 100644
--- a/libavcodec/resample2.c
+++ b/libavcodec/resample2.c
@@ -28,12 +28,6 @@
#include "common.h"
#include "dsputil.h"
-#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
@@ -60,6 +54,9 @@ typedef struct AVResampleContext{
int frac;
int src_incr;
int compensation_distance;
+ int phase_shift;
+ int phase_mask;
+ int linear;
}AVResampleContext;
/**
@@ -133,21 +130,26 @@ void av_build_filter(FELEM *filter, double factor, int tap_count, int phase_coun
* initalizes a audio resampler.
* note, if either rate is not a integer then simply scale both rates up so they are
*/
-AVResampleContext *av_resample_init(int out_rate, int in_rate){
+AVResampleContext *av_resample_init(int out_rate, int in_rate, int filter_size, int phase_shift, int linear){
AVResampleContext *c= av_mallocz(sizeof(AVResampleContext));
double factor= FFMIN(out_rate / (double)in_rate, 1.0);
-
+ int phase_count= 1<<phase_shift;
+
memset(c, 0, sizeof(AVResampleContext));
+
+ c->phase_shift= phase_shift;
+ c->phase_mask= phase_count-1;
+ c->linear= linear;
- 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(FELEM));
- c->filter_bank[c->filter_length*PHASE_COUNT]= c->filter_bank[c->filter_length - 1];
+ 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(FELEM));
+ c->filter_bank[c->filter_length*phase_count]= c->filter_bank[c->filter_length - 1];
c->src_incr= out_rate;
- c->ideal_dst_incr= c->dst_incr= in_rate * PHASE_COUNT;
- c->index= -PHASE_COUNT*((c->filter_length-1)/2);
+ c->ideal_dst_incr= c->dst_incr= in_rate * phase_count;
+ c->index= -phase_count*((c->filter_length-1)/2);
return c;
}
@@ -181,8 +183,8 @@ int av_resample(AVResampleContext *c, short *dst, short *src, int *consumed, int
int compensation_distance= c->compensation_distance;
for(dst_index=0; dst_index < dst_size; dst_index++){
- FELEM *filter= c->filter_bank + c->filter_length*(index & PHASE_MASK);
- int sample_index= index >> PHASE_SHIFT;
+ FELEM *filter= c->filter_bank + c->filter_length*(index & c->phase_mask);
+ int sample_index= index >> c->phase_shift;
FELEM2 val=0;
if(sample_index < 0){
@@ -190,8 +192,7 @@ int av_resample(AVResampleContext *c, short *dst, short *src, int *consumed, int
val += src[ABS(sample_index + i) % src_size] * filter[i];
}else if(sample_index + c->filter_length > src_size){
break;
- }else{
-#ifdef LINEAR
+ }else if(c->linear){
int64_t v=0;
int sub_phase= (frac<<8) / c->src_incr;
for(i=0; i<c->filter_length; i++){
@@ -199,11 +200,10 @@ int av_resample(AVResampleContext *c, short *dst, short *src, int *consumed, int
v += src[sample_index + i] * coeff;
}
val= v>>8;
-#else
+ }else{
for(i=0; i<c->filter_length; i++){
val += src[sample_index + i] * (FELEM2)filter[i];
}
-#endif
}
val = (val + (1<<(FILTER_SHIFT-1)))>>FILTER_SHIFT;
@@ -222,7 +222,7 @@ int av_resample(AVResampleContext *c, short *dst, short *src, int *consumed, int
dst_incr= c->ideal_dst_incr / c->src_incr;
}
}
- *consumed= FFMAX(index, 0) >> PHASE_SHIFT;
+ *consumed= FFMAX(index, 0) >> c->phase_shift;
index= FFMIN(index, 0);
if(compensation_distance){