File syn_sbc.h¶

FileList > audio > syn_sbc.h

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

#include "../common/syn_defs.h"
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>

Classes¶

Type	Name
struct	SYN_SBC_Decoder SBC Decoder Instance State (~1.5 KB static memory).
struct	SYN_SBC_FrameInfo SBC Parsed Frame Header Information.

Public Types¶

Type	Name
enum	SYN_SBC_AllocMethod SBC Allocation Method Enums.
enum	SYN_SBC_ChannelMode SBC Channel Mode Enums.

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.

Macros¶

Type	Name
define	SYN_SBC_SYNCWORD `0x9CU` SBC Frame Synchronization Byte (0x9C)

Detailed Description¶

Zero-heap, fixed-point integer implementation of the Bluetooth SIG SBC decoder (A2DP spec v1.3 / Bluetooth Core Spec AVTP). Supports 4 and 8 subbands, 4, 8, 12, 16 blocks, Mono/Dual Channel/Stereo/Joint Stereo, Loudness and SNR bit allocation, and sample rates 16k, 32k, 44.1k, 48k.

Public Types Documentation¶

enum SYN_SBC_AllocMethod¶

SBC Allocation Method Enums.

enum SYN_SBC_AllocMethod {
    SYN_SBC_ALLOC_LOUDNESS = 0,
    SYN_SBC_ALLOC_SNR = 1
};

enum SYN_SBC_ChannelMode¶

SBC Channel Mode Enums.

enum SYN_SBC_ChannelMode {
    SYN_SBC_MODE_MONO = 0,
    SYN_SBC_MODE_DUAL_CHANNEL = 1,
    SYN_SBC_MODE_STEREO = 2,
    SYN_SBC_MODE_JOINT_STEREO = 3
};

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.

Macro Definition Documentation¶

define SYN_SBC_SYNCWORD¶

SBC Frame Synchronization Byte (0x9C)

#define SYN_SBC_SYNCWORD `0x9CU`

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