第一次提交

e3_176_ref-buding/middleware/pdm/pdm_filter.h

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+#ifndef PDM_FILTER_H
+#define PDM_FILTER_H
+#define MAX_CH 4
+
+typedef struct {
+    short a0;
+    short a1;
+    short a2;
+    short b0;
+    short b1;
+    short b2;
+    short x1;
+    short x2;
+    short y1;
+    short y2;
+} pdm_coeff_t;
+
+/**
+ * @brief pdm filter handle
+ *
+ */
+typedef struct {
+    int sample_rate;
+    int channel;
+    pdm_coeff_t bq[MAX_CH];
+} pdm_filter_t;
+
+/**
+ * @brief
+ *
+ * @param pdm_filter
+ * @param sample_rate
+ * @param channel
+ * @return int
+ */
+int pdm_filter_init(pdm_filter_t *pdm_filter, int sample_rate, int channel);
+
+/**
+ * @brief
+ *
+ * @param pdm_filter
+ * @param inputPtr
+ * @param outputPtr
+ * @param framesize
+ * @return int
+ */
+int pdm_filter_process(pdm_filter_t *pdm_filter, void *inputPtr,
+                       void *outputPtr, int framesize);
+#endif