- completely drop ADF but copy necessary parts

o copy component audio_board from ADF and create custom component from it
  o copy component audio_hal from ADF and create custom component from it
  o copy component audio_sal from ADF and create custom component from it
  o copy component esp_peripherals from ADF and create custom component from it
- add fLaC support through xiph's original repository as a git module

components/audio_sal/include/audio_sys.h

@@ -0,0 +1,84 @@
+/*
+ * ESPRESSIF MIT License
+ *
+ * Copyright (c) 2019 <ESPRESSIF SYSTEMS (SHANGHAI) CO., LTD>
+ *
+ * Permission is hereby granted for use on all ESPRESSIF SYSTEMS products, in
+ * which case, it is free of charge, to any person obtaining a copy of this
+ * software and associated documentation files (the "Software"), to deal in the
+ * Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ */
+
+#ifndef _AUDIO_SYS_H_
+#define _AUDIO_SYS_H_
+
+#include "esp_err.h"
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+#define ___STR___(x) #x
+#define STR_AUDIO(x) ___STR___ (x)
+
+  /**
+   * @brief       Get system ticks by given millisecond
+   *
+   * @param[in]   ms millisecond
+   *
+   * @return
+   *     - tick
+   */
+  int audio_sys_get_tick_by_time_ms (int ms);
+
+  /**
+   * @brief   Get system time with millisecond
+   *
+   * @return
+   *     -  time with millisecond
+   */
+  int64_t audio_sys_get_time_ms (void);
+
+  /**
+   * @brief   Function to print the CPU usage of tasks over a given
+   * AUDIO_SYS_TASKS_ELAPSED_TIME_MS.
+   *
+   * This function will measure and print the CPU usage of tasks over a
+   * specified number of ticks (i.e. real time stats). This is implemented by
+   * simply calling uxTaskGetSystemState() twice separated by a delay, then
+   * calculating the differences of task run times before and after the delay.
+   *
+   * @note    If any tasks are added or removed during the delay, the stats of
+   *          those tasks will not be printed.
+   * @note    This function should be called from a high priority task to
+   * minimize inaccuracies with delays.
+   * @note    When running in dual core mode, each core will correspond to 50%
+   * of the run time.
+   *
+   * @return
+   *  - ESP_OK
+   *  - ESP_FIAL
+   */
+  esp_err_t audio_sys_get_real_time_stats (void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif