Review at https://gerrit.osmocom.org/2978
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
---
M Transceiver52M/Resampler.cpp
M Transceiver52M/Resampler.h
2 files changed, 39 insertions(+), 76 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/osmo-trx refs/changes/78/2978/1
diff --git a/Transceiver52M/Resampler.cpp b/Transceiver52M/Resampler.cpp
index 1927e45..3836b68 100644
--- a/Transceiver52M/Resampler.cpp
+++ b/Transceiver52M/Resampler.cpp
@@ -22,6 +22,7 @@
#include <string.h>
#include <malloc.h>
#include <iostream>
+#include <algorithm>
#include "Resampler.h"
@@ -35,6 +36,8 @@
#define MAX_OUTPUT_LEN 4096
+using namespace std;
+
static float sinc(float x)
{
if (x == 0.0)
@@ -43,32 +46,19 @@
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 @@
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 - 1]);
}
static bool check_vec_len(int in_len, int out_len, int p, int q)
@@ -159,14 +128,6 @@
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 @@
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 @@
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 @@
}
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()
{
- releaseFilters();
-
- delete in_index;
- delete out_path;
+ for (auto &part : partitions)
+ free(part);
}
diff --git a/Transceiver52M/Resampler.h b/Transceiver52M/Resampler.h
index c9f9787..caffc08 100644
--- a/Transceiver52M/Resampler.h
+++ b/Transceiver52M/Resampler.h
@@ -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 @@
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_ */
--
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Gerrit-MessageType: newchange
Gerrit-Change-Id: Ie836982794c10fb1b6334e40592d44b200454846
Gerrit-PatchSet: 1
Gerrit-Project: osmo-trx
Gerrit-Branch: master
Gerrit-Owner: Tom Tsou <[email protected]>
