/* SPDX-License-Identifier: BSD-3-Clause

*

* Copyright(c) 2020 Google LLC. All rights reserved.

*

* Author: Sebastiano Carlucci <scarlucci@google.com>

*/

#ifndef __SOF_AUDIO_DCBLOCK_DCBLOCK_H__

#define __SOF_AUDIO_DCBLOCK_DCBLOCK_H__

#include <stdint.h>

#include <sof/platform.h>

#include <ipc/stream.h>

struct audio_stream;

struct comp_dev;

struct dcblock_state {

int32_t x_prev; /**< state variable referring to x[n-1] */

int32_t y_prev; /**< state variable referring to y[n-1] */

};

/**

* \brief Type definition for the processing function for the

* DC Blocking Filter.

*/

typedef void (*dcblock_func)(const struct comp_dev *dev,

const struct audio_stream *source,

const struct audio_stream *sink,

uint32_t frames);

/* DC Blocking Filter component private data */

struct comp_data {

/**< filters state */

struct dcblock_state state[PLATFORM_MAX_CHANNELS];

/** coefficients for the processing function */

int32_t R_coeffs[PLATFORM_MAX_CHANNELS];

enum sof_ipc_frame source_format;

enum sof_ipc_frame sink_format;

dcblock_func dcblock_func; /**< processing function */

};

/** \brief DC Blocking Filter processing functions map item. */

struct dcblock_func_map {

enum sof_ipc_frame src_fmt; /**< source frame format */

dcblock_func func; /**< processing function */

};

/** \brief Map of formats with dedicated processing functions. */

extern const struct dcblock_func_map dcblock_fnmap[];

/** \brief Number of processing functions. */

extern const size_t dcblock_fncount;

/**

* \brief Retrieves a DC Blocking processing function matching

* the source buffer's frame format.

* \param src_fmt the frames' format of the source buffer

*/

static inline dcblock_func dcblock_find_func(enum sof_ipc_frame src_fmt)

{

int i;

/* Find suitable processing function from map */

for (i = 0; i < dcblock_fncount; i++) {

if (src_fmt == dcblock_fnmap[i].src_fmt)

return dcblock_fnmap[i].func;

}

return NULL;

}

#endif /* __SOF_AUDIO_DCBLOCK_DCBLOCK_H__ */