esp-idf/components/bt/bluedroid/external/sbc/plc/include/sbc_plc.h

92 lines
2.8 KiB
C

// Copyright 2015-2016 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 _SBC_PLC_H
#define _SBC_PLC_H
#include <stdint.h>
#if defined __cplusplus
extern "C" {
#endif
/* Paramter for PLC (16 kHZ)*/
#define SBC_FS 120 /* SBC Frame Size */
#define SBC_N 256 /* 16ms - Window Length for pattern matching */
#define SBC_M 64 /* 4ms - Template for matching */
#define SBC_LHIST (SBC_N + SBC_FS - 1) /* Length of history buffer required */
#define SBC_RT 36 /* SBC Reconvergence Time (samples) */
#define SBC_OLAL 16 /* OverLap-Add Length (samples) */
/* PLC State Information */
typedef struct sbc_plc_state {
int16_t hist[SBC_LHIST + SBC_FS + SBC_RT + SBC_OLAL];
int16_t bestlag;
int nbf;
} sbc_plc_state_t;
/* Prototypes */
/**
* Perform PLC initialization of memory vectors.
*
* @param plc_state pointer to PLC state memory
*/
void sbc_plc_init(sbc_plc_state_t *plc_state);
/**
* Perform PLC deinitialization of memory vectors.
*
* @param plc_state pointer to PLC state memory
*/
void sbc_plc_deinit(sbc_plc_state_t *plc_state);
/**
* Perform bad frame processing.
*
* @param plc_state pointer to PLC state memory
* @param ZIRbuf pointer to the ZIR response of the SBC decoder
* @param out pointer to the output samples
*/
void sbc_plc_bad_frame(sbc_plc_state_t *plc_state, int16_t *ZIRbuf, int16_t *out);
/**
* Perform good frame processing. Most of the time, this function
* just updates history buffers and passes the input to the output,
* but in the first good frame after frame loss, it must conceal the
* received signal as it reconverges with the true output.
*
* @param plc_state pointer to PLC state memory
* @param in pointer to the input vector
* @param out pointer to the output samples
*/
void sbc_plc_good_frame(sbc_plc_state_t *plc_state, int16_t *in, int16_t *out);
/**
* Get a zero signal eSCO frame
* @return pointer to data buffer
*/
uint8_t * sbc_plc_zero_signal_frame(void);
/**
* Get a zero signal eSCO pcm frame
* @return pointer to data buffer
*/
int16_t * sbc_plc_zero_signal_frame_pcm(void);
#if defined __cplusplus
}
#endif
#endif /// _SBC_PLC_H