audio_ring_buffer Struct Reference

Audio ring buffer for real-time audio streaming. More...

#include <include/ascii-chat/ringbuffer.h>

Data Fields
unsigned	channels
	Frame width, configured before the first read/write.
float	data [192000]
	Audio sample data buffer.
atomic_t	write_index
	Write index (producer position) - LOCK-FREE with atomic operations.
atomic_t	read_index
	Read index (consumer position) - LOCK-FREE with atomic operations.
atomic_t	discard_pending
	Consumer should discard queued samples before its next read.
atomic_t	discard_to_index
	Producer position at which the stale queue ends.
atomic_t	jitter_buffer_filled
	True after initial jitter buffer fill.
atomic_t	crossfade_samples_remaining
	Samples remaining in crossfade (0 = no crossfade active).
atomic_t	crossfade_fade_in
	True if we're fading in (recovering from underrun).
float	last_sample
	Last sample value for smooth fade-out during underrun - NOT atomic (only written by reader).
atomic_t	underrun_count
	Count of underrun events for diagnostics.
bool	jitter_buffer_enabled
	Whether jitter buffering is enabled (false for capture, true for playback).
uint32_t	jitter_target_samples
uint32_t	jitter_initial_samples
uint64_t	jitter_stable_samples
double	jitter_drift_phase
	Consumer-owned fractional clock correction.
mutex_t	mutex
	Mutex for SLOW PATH only (clear/destroy operations, not regular read/write).

Detailed Description

Audio ring buffer for real-time audio streaming.

Specialized ring buffer for audio samples with jitter buffering to compensate for network latency and packet timing variations. Uses mutex-protected operations for thread-safe audio access.

Features:

• Jitter buffering: waits for threshold fill before starting playback
• Low water mark: resets jitter state when buffer runs low
• Crossfade: smoothly fades audio in/out during underrun recovery
• Underrun tracking: counts underruns for diagnostics

Definition at line 208 of file ringbuffer.h.

Field Documentation

channels

unsigned audio_ring_buffer::channels

Frame width, configured before the first read/write.

Definition at line 209 of file ringbuffer.h.

Referenced by audio_ring_buffer_create_format(), audio_ring_buffer_read(), audio_ring_buffer_set_jitter_target(), audio_ring_buffer_write(), and mixer_add_source().

crossfade_fade_in

atomic_t audio_ring_buffer::crossfade_fade_in

True if we're fading in (recovering from underrun).

Definition at line 225 of file ringbuffer.h.

Referenced by audio_ring_buffer_clear(), audio_ring_buffer_read(), audio_ring_buffer_register_atomics(), and audio_ring_buffer_unregister_atomics().

crossfade_samples_remaining

atomic_t audio_ring_buffer::crossfade_samples_remaining

Samples remaining in crossfade (0 = no crossfade active).

Definition at line 223 of file ringbuffer.h.

Referenced by audio_ring_buffer_clear(), audio_ring_buffer_read(), audio_ring_buffer_register_atomics(), and audio_ring_buffer_unregister_atomics().

data

float audio_ring_buffer::data[192000]

Audio sample data buffer.

Definition at line 211 of file ringbuffer.h.

Referenced by audio_ring_buffer_clear(), audio_ring_buffer_peek(), audio_ring_buffer_read(), audio_ring_buffer_write(), and session_display_write_audio().

discard_pending

atomic_t audio_ring_buffer::discard_pending

Consumer should discard queued samples before its next read.

Definition at line 217 of file ringbuffer.h.

Referenced by audio_ring_buffer_clear(), audio_ring_buffer_discard_pending(), audio_ring_buffer_read(), audio_ring_buffer_register_atomics(), and audio_ring_buffer_unregister_atomics().

discard_to_index

atomic_t audio_ring_buffer::discard_to_index

Producer position at which the stale queue ends.

Definition at line 219 of file ringbuffer.h.

Referenced by audio_ring_buffer_clear(), audio_ring_buffer_discard_pending(), audio_ring_buffer_read(), audio_ring_buffer_register_atomics(), and audio_ring_buffer_unregister_atomics().

jitter_buffer_enabled

bool audio_ring_buffer::jitter_buffer_enabled

Whether jitter buffering is enabled (false for capture, true for playback).

Definition at line 231 of file ringbuffer.h.

Referenced by audio_ring_buffer_clear(), audio_ring_buffer_read(), audio_ring_buffer_write(), and audio_start_duplex().

jitter_buffer_filled

atomic_t audio_ring_buffer::jitter_buffer_filled

True after initial jitter buffer fill.

Definition at line 221 of file ringbuffer.h.

Referenced by audio_ring_buffer_clear(), audio_ring_buffer_read(), audio_ring_buffer_register_atomics(), and audio_ring_buffer_unregister_atomics().

jitter_drift_phase

double audio_ring_buffer::jitter_drift_phase

Consumer-owned fractional clock correction.

Definition at line 236 of file ringbuffer.h.

Referenced by audio_ring_buffer_clear(), audio_ring_buffer_read(), and audio_ring_buffer_set_jitter_target().

jitter_initial_samples

uint32_t audio_ring_buffer::jitter_initial_samples

Definition at line 234 of file ringbuffer.h.

Referenced by audio_ring_buffer_clear(), audio_ring_buffer_create_format(), audio_ring_buffer_read(), and audio_ring_buffer_set_jitter_target().

jitter_stable_samples

uint64_t audio_ring_buffer::jitter_stable_samples

Definition at line 235 of file ringbuffer.h.

Referenced by audio_ring_buffer_clear(), audio_ring_buffer_read(), and audio_ring_buffer_set_jitter_target().

jitter_target_samples

uint32_t audio_ring_buffer::jitter_target_samples

Consumer-owned adaptive target and stable-playback counter (48 kHz samples).

Definition at line 233 of file ringbuffer.h.

Referenced by audio_ring_buffer_clear(), audio_ring_buffer_create_format(), audio_ring_buffer_read(), and audio_ring_buffer_set_jitter_target().

last_sample

float audio_ring_buffer::last_sample

Last sample value for smooth fade-out during underrun - NOT atomic (only written by reader).

Definition at line 227 of file ringbuffer.h.

Referenced by audio_ring_buffer_clear(), and audio_ring_buffer_read().

mutex

mutex_t audio_ring_buffer::mutex

Mutex for SLOW PATH only (clear/destroy operations, not regular read/write).

Definition at line 238 of file ringbuffer.h.

Referenced by audio_ring_buffer_clear(), and audio_ring_buffer_destroy().

read_index

atomic_t audio_ring_buffer::read_index

Read index (consumer position) - LOCK-FREE with atomic operations.

Definition at line 215 of file ringbuffer.h.

Referenced by audio_ring_buffer_available_read(), audio_ring_buffer_clear(), audio_ring_buffer_peek(), audio_ring_buffer_read(), audio_ring_buffer_register_atomics(), audio_ring_buffer_unregister_atomics(), audio_ring_buffer_write(), and session_display_write_audio().

underrun_count

atomic_t audio_ring_buffer::underrun_count

Count of underrun events for diagnostics.

Definition at line 229 of file ringbuffer.h.

Referenced by audio_ring_buffer_read(), audio_ring_buffer_register_atomics(), and audio_ring_buffer_unregister_atomics().

write_index

atomic_t audio_ring_buffer::write_index

Write index (producer position) - LOCK-FREE with atomic operations.

Definition at line 213 of file ringbuffer.h.

Referenced by audio_ring_buffer_available_read(), audio_ring_buffer_clear(), audio_ring_buffer_discard_pending(), audio_ring_buffer_peek(), audio_ring_buffer_read(), audio_ring_buffer_register_atomics(), audio_ring_buffer_unregister_atomics(), audio_ring_buffer_write(), and session_display_write_audio().

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The documentation for this struct was generated from the following file:

• ringbuffer.h