audio.h File Reference

Audio formats and PCM conventions. More...

#include "audio_player/base.h"

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Data Structures
struct	audio_format_t

Macros
#define	AUDIO_MAX_CHANNELS   2

Enumerations
enum	rate_family_t { RATE_FAMILY_44K1 = 0 , RATE_FAMILY_48K = 1 , RATE_FAMILY_OTHER = 2 }
	44.1 kHz family (44100, 88200, 176400, 352800) or 48 kHz family (32000, 48000, 96000, 192000...). More...

Functions
static bool	audio_format_equal (const audio_format_t *a, const audio_format_t *b)
rate_family_t	audio_rate_family (uint32_t sample_rate)
static int32_t	audio_s16_to_q31 (int16_t v)
static int32_t	audio_s24_to_q31 (int32_t v24)
static int16_t	audio_q31_to_s16_trunc (int32_t v)
uint64_t	audio_ms_to_frames (uint32_t ms, uint32_t sample_rate)
uint32_t	audio_frames_to_ms (uint64_t frames, uint32_t sample_rate)

Detailed Description

Audio formats and PCM conventions.

PCM inside the pipeline is ALWAYS interleaved int32_t, left-justified (Q31): a 16-bit sample 0x1234 becomes 0x12340000, a 24-bit sample 0x123456 becomes 0x12345600. Full scale is INT32_MIN..INT32_MAX. This keeps 16/24/32-bit sources bit-exact when DSP is bypassed: the sink takes the top bits it needs.

DSD is carried as DoP (DSD over PCM, 176.4 kHz for DSD64, 24-bit payload in the top 24 bits with 0x05/0xFA markers). DoP frames must never pass through DSP or volume; audio_format_t.dop marks them.

Macro Definition Documentation

AUDIO_MAX_CHANNELS

#define AUDIO_MAX_CHANNELS   2

Enumeration Type Documentation

rate_family_t

enum rate_family_t

44.1 kHz family (44100, 88200, 176400, 352800) or 48 kHz family (32000, 48000, 96000, 192000...).

Enumerator
RATE_FAMILY_44K1
RATE_FAMILY_48K
RATE_FAMILY_OTHER

Function Documentation

audio_format_equal()

static bool audio_format_equal ( const audio_format_t *  a, const audio_format_t *  b  )

inlinestatic

audio_frames_to_ms()

uint32_t audio_frames_to_ms	(	uint64_t	frames,
		uint32_t	sample_rate
	)

audio_ms_to_frames()

uint64_t audio_ms_to_frames	(	uint32_t	ms,
		uint32_t	sample_rate
	)

audio_q31_to_s16_trunc()

static int16_t audio_q31_to_s16_trunc ( int32_t  v )

inlinestatic

audio_rate_family()

rate_family_t audio_rate_family

(

uint32_t

sample_rate

)

audio_s16_to_q31()

static int32_t audio_s16_to_q31 ( int16_t  v )

inlinestatic

audio_s24_to_q31()

static int32_t audio_s24_to_q31 ( int32_t  v24 )

inlinestatic