video_frame_buffer_t Struct Reference

Video frame buffer manager. More...

#include <lib/video/video_frame.h>

Data Fields
Double Buffering
video_frame_t *	front_buffer
	Currently displayed frame (reader owns)
video_frame_t *	back_buffer
	Currently written frame (writer owns)
Synchronization
atomic_bool	new_frame_available
	Atomic flag: true when new frame available.
mutex_t	swap_mutex
	Brief mutex for pointer swap only.
Frame Allocation
video_frame_t	frames [2]
	Pre-allocated frame structures (reused forever)
Statistics
atomic_ullong	total_frames_received
	Total frames received (atomic counter)
atomic_ullong	total_frames_dropped
	Total frames dropped (atomic counter)
atomic_ullong	last_frame_sequence
	Last frame sequence number (atomic)
Quality Metrics
atomic_uint	avg_decode_time_us
	Average decode time in microseconds (atomic)
atomic_uint	avg_render_time_us
	Average render time in microseconds (atomic)
Client Info
uint32_t	client_id
	Client ID this buffer belongs to.
bool	active
	True if buffer is active (receiving frames)
Buffer Management
size_t	allocated_buffer_size
	Size of allocated data buffers (for cleanup)

Detailed Description

Video frame buffer manager.

Implements double-buffered frame management with atomic pointer swaps for zero-copy frame transfer. Writer thread writes to back buffer while reader thread reads from front buffer. Atomic swap makes new frames available without blocking.

DOUBLE BUFFERING ARCHITECTURE:

• front_buffer: Currently displayed frame (reader owns)
• back_buffer: Currently written frame (writer owns)
• Atomic swap: Swaps front/back when writer commits frame

SYNCHRONIZATION:

• Atomic bool flag signals when new frame is available
• Brief mutex for pointer swap (minimal contention)
• Lock-free reads (reader never blocks writer)

STATISTICS TRACKING:

• Total frames received/dropped
• Frame drop rate
• Average decode/render times
• Quality metrics for adaptive streaming

Note

Pre-allocates buffers at creation time for zero-allocation operation.

Latest-frame-wins semantics (old frames are dropped, not queued).

Thread-safe: Writer and reader can operate concurrently.

Definition at line 176 of file video_frame.h.

Field Documentation

active

bool video_frame_buffer_t::active

True if buffer is active (receiving frames)

Definition at line 216 of file video_frame.h.

Referenced by video_frame_begin_write(), video_frame_buffer_create(), video_frame_buffer_destroy(), video_frame_commit(), video_frame_get_latest(), and video_frame_get_stats().

allocated_buffer_size

size_t video_frame_buffer_t::allocated_buffer_size

Size of allocated data buffers (for cleanup)

Definition at line 222 of file video_frame.h.

Referenced by client_video_render_thread(), video_frame_buffer_create(), and video_frame_buffer_destroy().

avg_decode_time_us

atomic_uint video_frame_buffer_t::avg_decode_time_us

Average decode time in microseconds (atomic)

Definition at line 208 of file video_frame.h.

Referenced by video_frame_get_stats().

avg_render_time_us

atomic_uint video_frame_buffer_t::avg_render_time_us

Average render time in microseconds (atomic)

Definition at line 209 of file video_frame.h.

Referenced by video_frame_get_stats().

back_buffer

video_frame_t* video_frame_buffer_t::back_buffer

Currently written frame (writer owns)

Definition at line 181 of file video_frame.h.

Referenced by video_frame_begin_write(), video_frame_buffer_create(), and video_frame_commit().

client_id

uint32_t video_frame_buffer_t::client_id

Client ID this buffer belongs to.

Definition at line 215 of file video_frame.h.

Referenced by video_frame_buffer_create(), and video_frame_commit().

frames

video_frame_t video_frame_buffer_t::frames[2]

Pre-allocated frame structures (reused forever)

Definition at line 194 of file video_frame.h.

Referenced by video_frame_buffer_create(), and video_frame_buffer_destroy().

front_buffer

video_frame_t* video_frame_buffer_t::front_buffer

Currently displayed frame (reader owns)

Definition at line 180 of file video_frame.h.

Referenced by video_frame_buffer_create(), video_frame_commit(), and video_frame_get_latest().

last_frame_sequence

atomic_ullong video_frame_buffer_t::last_frame_sequence

Last frame sequence number (atomic)

Definition at line 202 of file video_frame.h.

Referenced by video_frame_buffer_create().

new_frame_available

atomic_bool video_frame_buffer_t::new_frame_available

Atomic flag: true when new frame available.

Definition at line 187 of file video_frame.h.

Referenced by video_frame_buffer_create(), video_frame_commit(), and video_frame_get_latest().

swap_mutex

mutex_t video_frame_buffer_t::swap_mutex

Brief mutex for pointer swap only.

Definition at line 188 of file video_frame.h.

Referenced by video_frame_buffer_create(), and video_frame_buffer_destroy().

total_frames_dropped

atomic_ullong video_frame_buffer_t::total_frames_dropped

Total frames dropped (atomic counter)

Definition at line 201 of file video_frame.h.

Referenced by video_frame_buffer_create(), video_frame_commit(), and video_frame_get_stats().

total_frames_received

atomic_ullong video_frame_buffer_t::total_frames_received

Total frames received (atomic counter)

Definition at line 200 of file video_frame.h.

Referenced by video_frame_buffer_create(), video_frame_commit(), and video_frame_get_stats().

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

• video_frame.h