diff --git a/aptdec-cli/main.c b/aptdec-cli/main.c
index 581933f..c9da9e0 100644
--- a/aptdec-cli/main.c
+++ b/aptdec-cli/main.c
@@ -86,7 +86,7 @@ char *basename(const char *filename) {
 #endif
 
 int main(int argc, const char **argv) {
-    char version[128];
+    char version[128] = { 0 };
     get_version(version);
     printf("%s\n", version);
     // clang-format off
@@ -166,7 +166,7 @@ int main(int argc, const char **argv) {
 static int process_file(const char *path, options_t *opts) {
     const char *path_basename = basename((char *)path);
     const char *dot = strrchr(path_basename, '.');
-    char name[256];
+    char name[256] = { 0 };
     if (dot == NULL) {
         strncpy(name, path_basename, 255);
     } else {
@@ -181,7 +181,7 @@ static int process_file(const char *path, options_t *opts) {
 
     writer_t *realtime_png;
     if (opts->realtime) {
-        char filename[269];
+        char filename[269] = { 0 };
         sprintf(filename, "%s-decoding.png", name);
         realtime_png = writer_init(filename, APT_REGION_FULL, APTDEC_MAX_HEIGHT, PNG_COLOR_TYPE_GRAY, "Unknown");
 
@@ -209,7 +209,7 @@ static int process_file(const char *path, options_t *opts) {
     }
 
     // Decode image
-    float *data = (float *)malloc(APT_IMG_WIDTH * (APTDEC_MAX_HEIGHT+1) * sizeof(float));
+    float *data = calloc(APT_IMG_WIDTH * (APTDEC_MAX_HEIGHT+1), sizeof(float));
     size_t rows;
     for (rows = 0; rows < APTDEC_MAX_HEIGHT; rows++) {
         float *row = &data[rows * APT_IMG_WIDTH];
@@ -238,7 +238,7 @@ static int process_file(const char *path, options_t *opts) {
         writer_free(realtime_png);
 #pragma GCC diagnostic pop
 
-        char filename[269];
+        char filename[269] = { 0 };
         sprintf(filename, "%s-decoding.png", name);
         remove(filename);
     }
@@ -294,9 +294,9 @@ static int process_file(const char *path, options_t *opts) {
 
         if (strcmp(images[i], "thermal") == 0) {
             if (img.ch[1] >= 4) {
-                char filename[269];
+                char filename[269] = { 0 };
                 sprintf(filename, "%s-thermal.png", base);
-                char description[128];
+                char description[128] = { 0 };
                 sprintf(description, "Calibrated thermal image, channel %s - %s", channel_name[img.ch[1]], channel_desc[img.ch[1]]);
 
                 // Perform visible calibration
@@ -313,9 +313,9 @@ static int process_file(const char *path, options_t *opts) {
             }
         } else if (strcmp(images[i], "visible") == 0) {
             if (img.ch[0] <= 2) {
-                char filename[269];
+                char filename[269] = { 0 };
                 sprintf(filename, "%s-visible.png", base);
-                char description[128];
+                char description[128] = { 0 };
                 sprintf(description, "Calibrated visible image, channel %s - %s", channel_name[img.ch[0]], channel_desc[img.ch[0]]);
 
                 // Perform visible calibration
@@ -352,9 +352,9 @@ static int process_file(const char *path, options_t *opts) {
         }
 
         if (strcmp(images[i], "raw") == 0) {
-            char filename[269];
+            char filename[269] = { 0 };
             sprintf(filename, "%s-raw.png", base);
-            char description[128];
+            char description[128] = { 0 };
             sprintf(description,
                 "Raw image, channel %s - %s / %s - %s",
                 channel_name[img.ch[0]],
@@ -376,9 +376,9 @@ static int process_file(const char *path, options_t *opts) {
             writer_free(writer);
         } else if (strcmp(images[i], "lut") == 0) {
             if (opts->lut != NULL && opts->lut[0] != '\0') {
-                char filename[269];
+                char filename[269] = { 0 };
                 sprintf(filename, "%s-lut.png", base);
-                char description[128];
+                char description[128] = { 0 };
                 sprintf(description,
                     "LUT image, channel %s - %s / %s - %s",
                     channel_name[img.ch[0]],
@@ -387,7 +387,7 @@ static int process_file(const char *path, options_t *opts) {
                     channel_desc[img.ch[1]]
                 );
 
-                png_colorp lut = (png_colorp)malloc(sizeof(png_color)*256*256);
+                png_colorp lut = calloc(256*256, sizeof(png_color));
                 if (read_lut(opts->lut, lut)) {
                     writer_t *writer = writer_init(filename, APT_REGION_CHA, img.rows, PNG_COLOR_TYPE_RGB, description);
                     writer_write_image_lut(writer, &img, lut);
@@ -398,9 +398,9 @@ static int process_file(const char *path, options_t *opts) {
                 warning("Cannot create LUT image, missing -l/--lut");
             }
         } else if (strcmp(images[i], "a") == 0) {
-            char filename[269];
+            char filename[269] = { 0 };
             sprintf(filename, "%s-a.png", base);
-            char description[128];
+            char description[128] = { 0 };
             sprintf(description, "Channel A: %s - %s", channel_name[img.ch[0]], channel_desc[img.ch[0]]);
 
             writer_t *writer;
@@ -415,9 +415,9 @@ static int process_file(const char *path, options_t *opts) {
             }
             writer_free(writer);
         } else if (strcmp(images[i], "b") == 0) {
-            char filename[269];
+            char filename[269] = { 0 };
             sprintf(filename, "%s-b.png", base);
-            char description[128];
+            char description[128] = { 0 };
             sprintf(description, "Channel B: %s - %s", channel_name[img.ch[1]], channel_desc[img.ch[1]]);
 
             writer_t *writer;
@@ -517,7 +517,7 @@ static void write_line(writer_t *png, float *row) {
 }
 
 apt_image_t strip(apt_image_t img) {
-    uint8_t *data = (uint8_t *)malloc(img.rows * APT_IMG_WIDTH);
+    uint8_t *data = calloc(img.rows * APT_IMG_WIDTH, sizeof(uint8_t));
     for (size_t y = 0; y < img.rows; y++) {
         memcpy(&data[y*APT_IMG_WIDTH], &img.data[y*APT_IMG_WIDTH + APT_CHA_OFFSET], APT_CH_WIDTH);
         memcpy(&data[y*APT_IMG_WIDTH + APT_CH_WIDTH], &img.data[y*APT_IMG_WIDTH + APT_CHB_OFFSET], APT_CH_WIDTH);
@@ -534,4 +534,4 @@ int array_contains(char **array, char *value, size_t n) {
         }
     }
     return 0;
-}
\ No newline at end of file
+}
diff --git a/aptdec-cli/pngio.c b/aptdec-cli/pngio.c
index b267d12..c60feaf 100644
--- a/aptdec-cli/pngio.c
+++ b/aptdec-cli/pngio.c
@@ -25,7 +25,7 @@
 #include "util.h"
 
 writer_t *writer_init(const char *filename, apt_region_t region, uint32_t height, int color, char *channel) {
-    writer_t *png = (writer_t *)malloc(sizeof(writer_t));
+    writer_t *png = calloc(1, sizeof(writer_t));
     png->region = region;
 
     // Create writer
@@ -43,7 +43,7 @@ writer_t *writer_init(const char *filename, apt_region_t region, uint32_t height
 
     png_set_IHDR(png->png, png->info, png->region.width, height, 8, color, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
 
-    char version[128];
+    char version[128] = { 0 };
     int version_len = get_version(version);
 
     png_text text[] = {
diff --git a/libaptdec/dsp.c b/libaptdec/dsp.c
index 1bc2af1..c82a412 100644
--- a/libaptdec/dsp.c
+++ b/libaptdec/dsp.c
@@ -74,11 +74,11 @@ char *aptdec_get_version(void) {
 }
 
 fir_t *fir_init(size_t max_size, size_t ntaps) {
-    fir_t *fir = (fir_t *)malloc(sizeof(fir_t));
+    fir_t *fir = calloc(1, sizeof(fir_t));
     fir->ntaps = ntaps;
     fir->ring_size = max_size + ntaps;
-    fir->taps = (float *)malloc(ntaps * sizeof(float));
-    fir->ring_buffer = (float *)malloc((max_size + ntaps) * sizeof(float));
+    fir->taps = calloc(ntaps, sizeof(float));
+    fir->ring_buffer = calloc(max_size + ntaps, sizeof(float));
     return fir;
 }
 
@@ -89,7 +89,7 @@ void fir_free(fir_t *fir) {
 }
 
 pll_t *pll_init(float alpha, float beta, float min_freq, float max_freq, float sample_rate) {
-    pll_t *pll = (pll_t *)malloc(sizeof(pll_t));
+    pll_t *pll = calloc(1, sizeof(pll_t));
     pll->alpha = alpha;
     pll->beta = beta;
     pll->min_freq = M_TAUf * min_freq / sample_rate;
@@ -104,9 +104,11 @@ aptdec_t *aptdec_init(float sample_rate) {
         return NULL;
     }
 
-    aptdec_t *apt = (aptdec_t *)malloc(sizeof(aptdec_t));
+    aptdec_t *apt = calloc(1, sizeof(aptdec_t));
     apt->sample_rate = sample_rate;
     apt->sync_frequency = 1.0f;
+    apt->interpolator_n = APTDEC_BUFFER_SIZE;
+    apt->interpolator_offset = 0.0f;
 
     // PLL configuration
     // https://www.trondeau.com/blog/2011/8/13/control-loop-gain-values.html
diff --git a/libaptdec/effects.c b/libaptdec/effects.c
index 61ab0ae..1afec32 100644
--- a/libaptdec/effects.c
+++ b/libaptdec/effects.c
@@ -102,7 +102,7 @@ void apt_stretch(apt_image_t *img, apt_region_t region) {
 void apt_denoise(apt_image_t *img, apt_region_t region) {
     for (size_t y = 1; y < img->rows - 1; y++) {
         for (size_t x = 1; x < region.width - 1; x++) {
-            float pixels[9];
+            float pixels[9] = { 0.0f };
             int pixeln = 0;
             for (int y2 = -1; y2 < 2; y2++) {
                 for (int x2 = -1; x2 < 2; x2++) {
@@ -139,12 +139,12 @@ int apt_crop(apt_image_t *img) {
     const float sync_pattern[] = {-1, -1, -1, -1, 1, 1, -1, -1, 1, 1, -1, -1, 1,  1,  -1, -1, 1,  1,  -1, -1,
                                   1,  1,  -1, -1, 1, 1, -1, -1, 1, 1, -1, -1, -1, -1, -1, -1, -1, -1, 0};
 
-    float *spc_rows = (float *)malloc(img->rows * sizeof(float));
+    float *spc_rows = calloc(img->rows, sizeof(float));
     int startCrop = 0;
     int endCrop = img->rows;
 
     for (size_t y = 0; y < img->rows; y++) {
-        float temp[39];
+        float temp[39] = { 0.0f };
         for (size_t i = 0; i < 39; i++) {
             temp[i] = img->data[y * APT_IMG_WIDTH + i];
         }
diff --git a/libaptdec/image.c b/libaptdec/image.c
index 5982c7d..e6498bd 100644
--- a/libaptdec/image.c
+++ b/libaptdec/image.c
@@ -21,9 +21,9 @@
 #include <stdlib.h>
 #include <string.h>
 #include <float.h>
+#include <aptdec.h>
 
 #include "algebra.h"
-#include <aptdec.h>
 #include "util.h"
 #include "calibration.h"
 
@@ -31,14 +31,14 @@
 
 apt_image_t apt_image_clone(apt_image_t img) {
     apt_image_t _img = img;
-    _img.data = (uint8_t *)malloc(APT_IMG_WIDTH * img.rows);
+    _img.data = calloc(APT_IMG_WIDTH * img.rows, sizeof(uint8_t));
     memcpy(_img.data, img.data, APT_IMG_WIDTH * img.rows);
     return _img;
 }
 
 static void decode_telemetry(const float *data, size_t rows, size_t offset, float *wedges) {
     // Calculate row average
-    float *telemetry_rows = (float *)malloc(rows * sizeof(float));
+    float *telemetry_rows = calloc(rows, sizeof(float));
     for (size_t y = 0; y < rows; y++) {
         telemetry_rows[y] = meanf(&data[y*APT_IMG_WIDTH + offset + APT_CH_WIDTH], APT_TELEMETRY_WIDTH);
     }
@@ -59,7 +59,7 @@ static void decode_telemetry(const float *data, size_t rows, size_t offset, floa
     // Find the least noisy frame (via standard deviation)
     float best_noise = FLT_MAX;
     size_t best_frame = 0;
-    for (size_t y = telemetry_offset; y < rows; y += APT_FRAME_LEN) {
+    for (size_t y = telemetry_offset; y < rows-APT_FRAME_LEN; y += APT_FRAME_LEN) {
         float noise = 0.0f;
         for (size_t i = 0; i < APT_FRAME_WEDGES; i++) {
             noise += standard_deviation(&telemetry_rows[y + i*APT_WEDGE_HEIGHT], APT_WEDGE_HEIGHT);
@@ -79,7 +79,7 @@ static void decode_telemetry(const float *data, size_t rows, size_t offset, floa
 }
 
 static float average_spc(apt_image_t *img, size_t offset) {
-    float *rows = (float *)malloc(img->rows * sizeof(float));
+    float *rows = calloc(img->rows, sizeof(float));
     float average = 0.0f;
     for (size_t y = 0; y < img->rows; y++) {
         float row_average = 0.0f;
@@ -170,7 +170,7 @@ static void make_thermal_lut(apt_image_t *img, avhrr_channel_t ch, int satellite
     const float B  = calibration.rad[ch].B;
 
     // Compute PRT temperature
-    float T[4];
+    float T[4] = { 0.0f };
     for (size_t n = 0; n < 4; n++) {
         T[n] = quadratic_calc(img->telemetry[1][n + 9] * APT_COUNT_RATIO, calibration.prt[n]);
     }
@@ -201,7 +201,7 @@ int apt_calibrate_thermal(apt_image_t *img, apt_region_t region) {
         return 1;
     }
 
-    float lut[256];
+    float lut[256] = { 0.0f };
     make_thermal_lut(img, img->ch[1], img->satellite, lut);
 
     for (size_t y = 0; y < img->rows; y++) {