add some code

managed_components/espressif__esp-dsp/modules/windows/hann/float/dsps_wind_hann_f32.c

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+// Copyright 2018-2019 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#define _USE_MATH_DEFINES
+#include "dsps_wind_hann.h"
+#include <math.h>
+
+void dsps_wind_hann_f32(float *window, int len)
+{
+    float len_mult = 1 / (float)(len - 1);
+    for (int i = 0; i < len; i++) {
+        window[i] = 0.5 * (1 - cosf(i * 2 * M_PI * len_mult));
+    }
+}

managed_components/espressif__esp-dsp/modules/windows/hann/include/dsps_wind_hann.h

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+// Copyright 2018-2019 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+
+#ifndef _dsps_wind_hann_H_
+#define _dsps_wind_hann_H_
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+/**
+ * @brief   Hann window
+ *
+ * The function generates Hann window.
+ *
+ * @param window: buffer to store window array.
+ * @param len: length of the window array
+ *
+ */
+void dsps_wind_hann_f32(float *window, int len);
+
+#ifdef __cplusplus
+}
+#endif
+#endif // _dsps_wind_hann_H_