GMINL-3234: Reorganize filters a litle

The moving average filter has a new home: was transform.c, now
filtering.c, with a new name also.

Change-Id: I9670dc687f883bba205ee2525ff364d628d54828
Tracked-On: https://jira01.devtools.intel.com/browse/GMINL-3234
Signed-off-by: Patrick Porlan <patrick.porlan@intel.com>

diff --git a/filtering.c b/filtering.c
index 9217de6..adabb30 100644 (file)
--- a/filtering.c
+++ b/filtering.c
@@ -188,3 +188,75 @@ void record_sample (int s, const struct sensors_event_t* event)
 
        memcpy(&cell->data, event, sizeof(sensors_event_t));
 }
+
+
+void denoise_average ( struct sensor_info_t* si, struct sensors_event_t* data,
+                       int num_fields, int max_samples)
+{
+       /*
+        * Smooth out incoming data using a moving average over a number of
+        * samples. We accumulate one second worth of samples, or max_samples,
+        * depending on which is lower.
+        */
+
+       int i;
+       int f;
+       int sampling_rate = (int) si->sampling_rate;
+       int history_size;
+       int history_full = 0;
+
+       /* Don't denoise anything if we have less than two samples per second */
+       if (sampling_rate < 2)
+               return;
+
+       /* Restrict window size to the min of sampling_rate and max_samples */
+       if (sampling_rate > max_samples)
+               history_size = max_samples;
+       else
+               history_size = sampling_rate;
+
+       /* Reset history if we're operating on an incorrect window size */
+       if (si->history_size != history_size) {
+               si->history_size = history_size;
+               si->history_entries = 0;
+               si->history_index = 0;
+               si->history = (float*) realloc(si->history,
+                               si->history_size * num_fields * sizeof(float));
+               if (si->history) {
+                       si->history_sum = (float*) realloc(si->history_sum,
+                               num_fields * sizeof(float));
+                       if (si->history_sum)
+                               memset(si->history_sum, 0, num_fields * sizeof(float));
+               }
+       }
+
+       if (!si->history || !si->history_sum)
+               return; /* Unlikely, but still... */
+
+       /* Update initialized samples count */
+       if (si->history_entries < si->history_size)
+               si->history_entries++;
+       else
+               history_full = 1;
+
+       /* Record new sample and calculate the moving sum */
+       for (f=0; f < num_fields; f++) {
+               /**
+                * A field is going to be overwritten if
+                * history is full, so decrease the history sum
+                */
+               if (history_full)
+                       si->history_sum[f] -=
+                               si->history[si->history_index * num_fields + f];
+
+               si->history[si->history_index * num_fields + f] = data->data[f];
+               si->history_sum[f] += data->data[f];
+
+               /* For now simply compute a mobile mean for each field */
+               /* and output filtered data */
+               data->data[f] = si->history_sum[f] / si->history_entries;
+       }
+
+       /* Update our rolling index (next evicted cell) */
+       si->history_index = (si->history_index + 1) % si->history_size;
+}

diff --git a/filtering.h b/filtering.h
index a0d903f..14ee1e9 100644 (file)
--- a/filtering.h
+++ b/filtering.h
@@ -7,5 +7,8 @@ void denoise_median_init(int s, unsigned int num_fields,
        unsigned int max_samples);
 void denoise_median_release(int s);
 
+void denoise_average ( struct sensor_info_t* si, struct sensors_event_t* data,
+                       int num_fields, int max_samples);
+
 void record_sample(int s, const sensors_event_t* data);
 #endif

diff --git a/transform.c b/transform.c
index ca837c4..ac90c94 100644 (file)
--- a/transform.c
+++ b/transform.c
@@ -189,78 +189,6 @@ static void reorder_fields(float* data,    unsigned char map[MAX_CHANNELS])
 }
 
 
-static void denoise (struct sensor_info_t* si, struct sensors_event_t* data,
-                    int num_fields, int max_samples)
-{
-       /*
-        * Smooth out incoming data using a moving average over a number of
-        * samples. We accumulate one second worth of samples, or max_samples,
-        * depending on which is lower.
-        */
-
-       int i;
-       int f;
-       int sampling_rate = (int) si->sampling_rate;
-       int history_size;
-       int history_full = 0;
-
-       /* Don't denoise anything if we have less than two samples per second */
-       if (sampling_rate < 2)
-               return;
-
-       /* Restrict window size to the min of sampling_rate and max_samples */
-       if (sampling_rate > max_samples)
-               history_size = max_samples;
-       else
-               history_size = sampling_rate;
-
-       /* Reset history if we're operating on an incorrect window size */
-       if (si->history_size != history_size) {
-               si->history_size = history_size;
-               si->history_entries = 0;
-               si->history_index = 0;
-               si->history = (float*) realloc(si->history,
-                               si->history_size * num_fields * sizeof(float));
-               if (si->history) {
-                       si->history_sum = (float*) realloc(si->history_sum,
-                               num_fields * sizeof(float));
-                       if (si->history_sum)
-                               memset(si->history_sum, 0, num_fields * sizeof(float));
-               }
-       }
-
-       if (!si->history || !si->history_sum)
-               return; /* Unlikely, but still... */
-
-       /* Update initialized samples count */
-       if (si->history_entries < si->history_size)
-               si->history_entries++;
-       else
-               history_full = 1;
-
-       /* Record new sample and calculate the moving sum */
-       for (f=0; f < num_fields; f++) {
-               /**
-                * A field is going to be overwritten if
-                * history is full, so decrease the history sum
-                */
-               if (history_full)
-                       si->history_sum[f] -=
-                               si->history[si->history_index * num_fields + f];
-
-               si->history[si->history_index * num_fields + f] = data->data[f];
-               si->history_sum[f] += data->data[f];
-
-               /* For now simply compute a mobile mean for each field */
-               /* and output filtered data */
-               data->data[f] = si->history_sum[f] / si->history_entries;
-       }
-
-       /* Update our rolling index (next evicted cell) */
-       si->history_index = (si->history_index + 1) % si->history_size;
-}
-
-
 static void clamp_gyro_readings_to_zero (int s, struct sensors_event_t* data)
 {
        float x, y, z;
@@ -329,13 +257,13 @@ static int finalize_sample_default (int s, struct sensors_event_t* data)
                        /* Always consider the accelerometer accurate */
                        data->acceleration.status = SENSOR_STATUS_ACCURACY_HIGH;
                        if (sensor_info[s].quirks & QUIRK_NOISY)
-                               denoise(&sensor_info[s], data, 3, 20);
+                               denoise_average(&sensor_info[s], data, 3, 20);
                        break;
 
                case SENSOR_TYPE_MAGNETIC_FIELD:
                        calibrate_compass (data, &sensor_info[s], get_timestamp());
                        if (sensor_info[s].quirks & QUIRK_NOISY)
-                               denoise(&sensor_info[s], data, 3, 30);
+                               denoise_average(&sensor_info[s], data, 3, 30);
                        break;
 
                case SENSOR_TYPE_GYROSCOPE: