1 /* 2 * SPDX-FileCopyrightText: 2015-2021 Espressif Systems (Shanghai) CO LTD 3 * 4 * SPDX-License-Identifier: Apache-2.0 5 */ 6 7 #ifndef _SBC_PLC_H 8 #define _SBC_PLC_H 9 10 #include <stdint.h> 11 12 #if defined __cplusplus 13 extern "C" { 14 #endif 15 16 /* Paramter for PLC (16 kHZ)*/ 17 #define SBC_FS 120 /* SBC Frame Size */ 18 #define SBC_N 256 /* 16ms - Window Length for pattern matching */ 19 #define SBC_M 64 /* 4ms - Template for matching */ 20 #define SBC_LHIST (SBC_N + SBC_FS - 1) /* Length of history buffer required */ 21 #define SBC_RT 36 /* SBC Reconvergence Time (samples) */ 22 #define SBC_OLAL 16 /* OverLap-Add Length (samples) */ 23 24 /* PLC State Information */ 25 typedef struct sbc_plc_state { 26 int16_t hist[SBC_LHIST + SBC_FS + SBC_RT + SBC_OLAL]; 27 int16_t bestlag; 28 int nbf; 29 } sbc_plc_state_t; 30 31 /* Prototypes */ 32 /** 33 * Perform PLC initialization of memory vectors. 34 * 35 * @param plc_state pointer to PLC state memory 36 */ 37 void sbc_plc_init(sbc_plc_state_t *plc_state); 38 39 /** 40 * Perform PLC deinitialization of memory vectors. 41 * 42 * @param plc_state pointer to PLC state memory 43 */ 44 void sbc_plc_deinit(sbc_plc_state_t *plc_state); 45 46 /** 47 * Perform bad frame processing. 48 * 49 * @param plc_state pointer to PLC state memory 50 * @param ZIRbuf pointer to the ZIR response of the SBC decoder 51 * @param out pointer to the output samples 52 */ 53 void sbc_plc_bad_frame(sbc_plc_state_t *plc_state, int16_t *ZIRbuf, int16_t *out); 54 55 /** 56 * Perform good frame processing. Most of the time, this function 57 * just updates history buffers and passes the input to the output, 58 * but in the first good frame after frame loss, it must conceal the 59 * received signal as it reconverges with the true output. 60 * 61 * @param plc_state pointer to PLC state memory 62 * @param in pointer to the input vector 63 * @param out pointer to the output samples 64 */ 65 void sbc_plc_good_frame(sbc_plc_state_t *plc_state, int16_t *in, int16_t *out); 66 67 /** 68 * Get a zero signal eSCO frame 69 * @return pointer to data buffer 70 */ 71 uint8_t * sbc_plc_zero_signal_frame(void); 72 73 /** 74 * Get a zero signal eSCO pcm frame 75 * @return pointer to data buffer 76 */ 77 int16_t * sbc_plc_zero_signal_frame_pcm(void); 78 79 #if defined __cplusplus 80 } 81 #endif 82 83 #endif /// _SBC_PLC_H 84
