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sigProcLib: Replace dynamically allocated resampling buffers 

Instead use object allocated STL vectors. This simplifies code,
removes the need to explicitly release buffers, and fixes a
memory leak in destructor deallocation. Also, remove simplified
init and release sub-calls.

Maintain partition filter allocation using memalign() for SIMD
alignment requirements.

Change-Id: Ie836982794c10fb1b6334e40592d44b200454846
This commit is contained in:
Tom Tsou 2017-06-19 15:23:59 -07:00 committed by Tom Tsou
parent a3dce85ffc
commit d2e5c5694e
2 changed files with 39 additions and 76 deletions
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101
Transceiver52M/Resampler.cpp
View File

@ -22,6 +22,7 @@
#include <string.h>
#include <malloc.h>
#include <iostream>
#include <algorithm>
#include "Resampler.h"
@ -35,6 +36,8 @@ extern "C" {
#define MAX_OUTPUT_LEN 4096
using namespace std;
static float sinc(float x)
{
if (x == 0.0)
@ -43,32 +46,19 @@ static float sinc(float x)
return sin(M_PI * x) / (M_PI * x);
}
bool Resampler::initFilters(float bw)
void Resampler::initFilters(float bw)
{
size_t proto_len = p * filt_len;
float *proto, val, cutoff;
float cutoff;
float sum = 0.0f, scale = 0.0f;
float midpt = (float) (proto_len - 1.0) / 2.0;
/*
* Allocate partition filters and the temporary prototype filter
* according to numerator of the rational rate. Coefficients are
* real only and must be 16-byte memory aligned for SSE usage.
*/
proto = new float[proto_len];
if (!proto)
return false;
partitions = (float **) malloc(sizeof(float *) * p);
if (!partitions) {
delete[] proto;
return false;
}
for (size_t i = 0; i < p; i++) {
partitions[i] = (float *)
memalign(16, filt_len * 2 * sizeof(float));
}
auto proto = vector<float>(p * filt_len);
for (auto &part : partitions)
part = (complex<float> *) memalign(16, filt_len * sizeof(complex<float>));
/*
* Generate the prototype filter with a Blackman-harris window.
@ -85,47 +75,26 @@ bool Resampler::initFilters(float bw)
else
cutoff = (float) q;
for (size_t i = 0; i < proto_len; i++) {
float midpt = (proto.size() - 1) / 2.0;
for (size_t i = 0; i < proto.size(); i++) {
proto[i] = sinc(((float) i - midpt) / cutoff * bw);
proto[i] *= a0 -
a1 * cos(2 * M_PI * i / (proto_len - 1)) +
a2 * cos(4 * M_PI * i / (proto_len - 1)) -
a3 * cos(6 * M_PI * i / (proto_len - 1));
a1 * cos(2 * M_PI * i / (proto.size() - 1)) +
a2 * cos(4 * M_PI * i / (proto.size() - 1)) -
a3 * cos(6 * M_PI * i / (proto.size() - 1));
sum += proto[i];
}
scale = p / sum;
/* Populate filter partitions from the prototype filter */
for (size_t i = 0; i < filt_len; i++) {
for (size_t n = 0; n < p; n++) {
partitions[n][2 * i + 0] = proto[i * p + n] * scale;
partitions[n][2 * i + 1] = 0.0f;
}
for (size_t n = 0; n < p; n++)
partitions[n][i] = complex<float>(proto[i * p + n] * scale);
}
/* For convolution, we store the filter taps in reverse */
for (size_t n = 0; n < p; n++) {
for (size_t i = 0; i < filt_len / 2; i++) {
val = partitions[n][2 * i];
partitions[n][2 * i] = partitions[n][2 * (filt_len - 1 - i)];
partitions[n][2 * (filt_len - 1 - i)] = val;
}
}
delete[] proto;
return true;
}
void Resampler::releaseFilters()
{
if (partitions) {
for (size_t i = 0; i < p; i++)
free(partitions[i]);
}
free(partitions);
partitions = NULL;
/* Store filter taps in reverse */
for (auto &part : partitions)
reverse(&part[0], &part[filt_len]);
}
static bool check_vec_len(int in_len, int out_len, int p, int q)
@ -159,14 +128,6 @@ static bool check_vec_len(int in_len, int out_len, int p, int q)
return true;
}
void Resampler::computePath()
{
for (int i = 0; i < MAX_OUTPUT_LEN; i++) {
in_index[i] = (q * i) / p;
out_path[i] = (q * i) % p;
}
}
int Resampler::rotate(const float *in, size_t in_len, float *out, size_t out_len)
{
int n, path;
@ -180,8 +141,8 @@ int Resampler::rotate(const float *in, size_t in_len, float *out, size_t out_len
path = out_path[i];
convolve_real(in, in_len,
partitions[path], filt_len,
&out[2 * i], out_len - i,
reinterpret_cast<float *>(partitions[path]),
filt_len, &out[2 * i], out_len - i,
n, 1, 1, 0);
}
@ -190,14 +151,18 @@ int Resampler::rotate(const float *in, size_t in_len, float *out, size_t out_len
bool Resampler::init(float bw)
{
if (p == 0 || q == 0 || filt_len == 0) return false;
/* Filterbank filter internals */
if (!initFilters(bw))
return false;
initFilters(bw);
/* Precompute filterbank paths */
in_index = new size_t[MAX_OUTPUT_LEN];
out_path = new size_t[MAX_OUTPUT_LEN];
computePath();
int i = 0;
for (auto &index : in_index)
index = (q * i++) / p;
i = 0;
for (auto &path : out_path)
path = (q * i++) % p;
return true;
}
@ -208,7 +173,7 @@ size_t Resampler::len()
}
Resampler::Resampler(size_t p, size_t q, size_t filt_len)
: in_index(NULL), out_path(NULL), partitions(NULL)
: in_index(MAX_OUTPUT_LEN), out_path(MAX_OUTPUT_LEN), partitions(p)
{
this->p = p;
this->q = q;
@ -217,8 +182,6 @@ Resampler::Resampler(size_t p, size_t q, size_t filt_len)
Resampler::~Resampler()
{
releaseFilters();
delete in_index;
delete out_path;
for (auto &part : partitions)
free(part);
}

14
Transceiver52M/Resampler.h
View File

@ -20,6 +20,9 @@
#ifndef _RESAMPLER_H_
#define _RESAMPLER_H_
#include <vector>
#include <complex>
class Resampler {
public:
/* Constructor for rational sample rate conversion
@ -63,14 +66,11 @@ private:
size_t p;
size_t q;
size_t filt_len;
size_t *in_index;
size_t *out_path;
std::vector<size_t> in_index;
std::vector<size_t> out_path;
std::vector<std::complex<float> *> partitions;
float **partitions;
bool initFilters(float bw);
void releaseFilters();
void computePath();
void initFilters(float bw);
};
#endif /* _RESAMPLER_H_ */