File syn_sbc.c¶

FileList > audio > syn_sbc.c

Bluetooth A2DP Sub-Band Codec (SBC) Decoder implementation.

#include "../util/syn_assert.h"
#include "syn_sbc.h"
#include <string.h>

Public Static Attributes¶

Type	Name
const int32_t	proto4_40 = `/* multi line expression */`
const int32_t	proto8_80 = `/* multi line expression */`
const int32_t	syn_cos4 = `/* multi line expression */`
const int32_t	syn_cos8 = `/* multi line expression */`

Public Functions¶

Type	Name
SYN_Status	syn_sbc_decode_frame (SYN_SBC_Decoder * dec, const uint8_t * in, size_t in_len, int16_t * pcm_out, size_t pcm_cap, size_t * out_samples) Decode a single SBC audio frame to 16-bit interleaved PCM samples.
void	syn_sbc_decoder_init (SYN_SBC_Decoder * dec) Initialize an SBC decoder instance.
SYN_Status	syn_sbc_parse_header (const uint8_t * data, size_t len, SYN_SBC_FrameInfo * info) Parse an SBC frame header without decoding audio payload.

Public Static Attributes Documentation¶

variable proto4_40¶

const int32_t proto4_40[40];

SBC Proto4 Windowing Coefficients for 4-subband synthesis

variable proto8_80¶

const int32_t proto8_80[80];

SBC Proto8 Windowing Coefficients for 8-subband synthesis (scaled fixed-point Q15)

variable syn_cos4¶

const int32_t syn_cos4[8][4];

IDCT matrix coefficients Q15 for 4 subbands

variable syn_cos8¶

const int32_t syn_cos8[16][8];

IDCT matrix coefficients Q15 for 8 subbands

Public Functions Documentation¶

function syn_sbc_decode_frame¶

Decode a single SBC audio frame to 16-bit interleaved PCM samples.

SYN_Status syn_sbc_decode_frame (
    SYN_SBC_Decoder * dec,
    const uint8_t * in,
    size_t in_len,
    int16_t * pcm_out,
    size_t pcm_cap,
    size_t * out_samples
)

Parameters:

dec Decoder context pointer.
in Input SBC frame buffer starting at syncword 0x9C.
in_len Input frame buffer length.
pcm_out Output 16-bit PCM buffer (interleaved stereo or mono).
pcm_cap Capacity of output PCM buffer in samples.
out_samples Output pointer receiving actual decoded sample count.

Returns:

SYN_OK on successful frame decode, or error code (<0).

function syn_sbc_decoder_init¶

Initialize an SBC decoder instance.

void syn_sbc_decoder_init (
    SYN_SBC_Decoder * dec
)

Parameters:

dec Decoder context pointer.

function syn_sbc_parse_header¶

Parse an SBC frame header without decoding audio payload.

SYN_Status syn_sbc_parse_header (
    const uint8_t * data,
    size_t len,
    SYN_SBC_FrameInfo * info
)

Parameters:

data Input byte buffer containing SBC stream.
len Length of input buffer in bytes.
info Output frame header structure.

Returns:

SYN_OK on success, or SYN_INVALID_PARAM / SYN_ERROR if syncword missing or invalid.

The documentation for this class was generated from the following file src/syntropic/audio/syn_sbc.c