Handles prefetching and caching of video/audio frames for smooth playback. More...

#include <Qt/VideoCacheThread.h>

Inheritance diagram for openshot::VideoCacheThread:

Public Member Functions
void	AcknowledgeAudioCacheMiss ()

int64_t	CancellationAcknowledgementUs () const

void	EnableRequestDiagnostics (bool enabled)

int64_t	FirstCurrentFrameUs () const

int	getSpeed () const

bool	isReady ()
	Shared startup gate; bounded fallback resumes established video decoding.

void	NotifyAudioCacheMiss ()

void	NotifyPlaybackPosition (int64_t new_position)
	Update playback position without triggering seek behavior or cache invalidation.

int64_t	ObsoleteCompletionUs () const

void	Play ()
	Play method is unimplemented.

void	Reader (ReaderBase *new_reader)
	Attach a ReaderBase (e.g. Timeline, FFmpegReader) and begin caching.

void	Seek (int64_t new_position)
	Backward-compatible alias for playback position updates (no seek side effects).

void	Seek (int64_t new_position, bool start_preroll)
	Seek to a specific frame and optionally start a preroll (cache reset).

void	setSpeed (int new_speed)
	Set playback speed/direction. Positive = forward, negative = rewind, zero = pause.

bool	StartThread ()
	Start the cache thread at high priority. Returns true if it’s actually running.

void	Stop ()
	Stop method is unimplemented.

bool	StopThread (int timeoutMs=0)
	Stop the cache thread (wait up to timeoutMs ms). Returns true if it stopped.

bool	UsesCachedAudio () const
	Callback miss holds the shared gate until the player resynchronizes audio.

	VideoCacheThread ()
	Constructor: initializes member variables and assumes forward direction on first launch.

	~VideoCacheThread () override

Protected Member Functions
void	acknowledgeRequest (int64_t started_us)

int64_t	clampToTimelineRange (int64_t frame, int64_t timeline_end) const
	Clamp frame index to [1, timeline_end] when timeline_end is valid.

bool	clearCacheIfPaused (int64_t playhead, bool paused, CacheBase *cache)
	When paused and playhead is outside current cache, clear all frames.

int	computeDirection () const

int64_t	computePrerollFrames (const Settings *settings) const
	Compute preroll frame count from settings.

void	computeWindowBounds (int64_t playhead, int dir, int64_t ahead_count, int64_t timeline_end, int64_t &window_begin, int64_t &window_end) const
	Compute the “window” of frames to cache around playhead.

int64_t	getBytes (int width, int height, int sample_rate, int channels, float fps)
	Estimate memory usage for a single frame (video + audio).

void	handleUserSeek (int64_t playhead, int dir)
	If userSeeked is true, reset last_cached_index just behind the playhead.

void	handleUserSeekWithPreroll (int64_t playhead, int dir, int64_t timeline_end, int64_t preroll_frames)
	Reset last_cached_index to start caching with a directional preroll offset.

bool	prefetchWindow (CacheBase cache, int64_t window_begin, int64_t window_end, int dir, ReaderBase reader, int64_t max_frames_to_fetch=-1, uint64_t generation=UINT64_MAX)
	Prefetch all missing frames in [window_begin ... window_end] or [window_end ... window_begin].

void	resetReadiness ()

int64_t	resolveTimelineEnd () const
	Resolve timeline end frame from reader/timeline metadata.

void	run () override
	Thread entry point: loops until threadShouldExit() is true.

void	updateReadiness (CacheBase *cache, int64_t playhead, int dir)
	Worker-only cache probing; never runs in the audio callback.

Static Protected Member Functions
static int64_t	monotonicUs ()

Protected Attributes
std::atomic< int64_t >	acknowledgement_us {0}

std::atomic< bool >	audio_cache_miss {false}

std::atomic< bool >	cache_audio_only {false}

std::atomic< int64_t >	cached_frame_count
	Estimated count of frames currently stored in cache.

std::atomic< bool >	clear_cache_on_next_fill
	True if next cache loop should clear existing cache ranges.

int64_t	contiguous_ahead = 0

int64_t	current_display_frame
	Currently displayed frame (unused here, reserved).

std::atomic< bool >	diagnostics_enabled {false}

std::atomic< int64_t >	first_current_frame_us {0}

bool	force_directional_cache
	(Reserved for future use).

std::shared_ptr< Frame >	last_cached_frame
	Last frame pointer added to cache.

std::atomic< int64_t >	last_cached_index
	Index of the most recently cached frame.

std::atomic< int >	last_dir
	Last direction sign (+1 forward, –1 backward).

std::atomic< int >	last_speed
	Last non-zero speed (for tracking).

std::mutex	lifecycle_mutex
	Start/stop/reader drain; never acquired by worker.

std::atomic< int64_t >	min_frames_ahead
	Minimum number of frames considered “ready” (pre-roll).

int64_t	observed_frame_bytes = 0

std::atomic< int64_t >	obsolete_completion_us {0}

std::atomic< bool >	preroll_on_next_fill
	True if next cache rebuild should include preroll offset.

AdaptivePreroll	preroll_policy

std::atomic< uint64_t >	processed_generation {UINT64_MAX}
	Last request whose scheduling baseline was consumed.

ReaderBase *	reader
	The source reader (e.g., Timeline, FFmpegReader).

int64_t	readiness_bytes_per_frame = 0

int64_t	readiness_capacity = 0

int	readiness_direction = 1

uint64_t	readiness_epoch = 0

uint64_t	readiness_generation = UINT64_MAX
	Request covered by the readiness snapshot.

int64_t	readiness_minimum_step = 0

int64_t	readiness_physical_capacity = 0

int64_t	readiness_playhead = 1

int64_t	readiness_timeline_end = 0

std::atomic< uint64_t >	request_generation {0}
	Invalidates obsolete fills, including seeks retaining cache.

std::atomic< int64_t >	request_time_us {0}

std::atomic< int64_t >	requested_display_frame
	Frame index the user requested.

std::atomic< bool >	scrub_active
	True while user is dragging/scrubbing the playhead.

std::mutex	seek_state_mutex
	Protects coherent seek state updates/consumption.

uint64_t	seen_timeline_cache_epoch
	Last observed Timeline cache invalidation epoch.

std::atomic< int >	speed
	Current playback speed (0=paused, >0 forward, <0 backward).

bool	timeline_cache_epoch_initialized
	True once an initial epoch snapshot has been taken.

int64_t	timeline_max_frame
	Highest valid frame index in the timeline.

std::atomic< bool >	userSeeked
	True if Seek(..., true) was called (forces a cache reset).

Detailed Description

Handles prefetching and caching of video/audio frames for smooth playback.

This thread continuously maintains a “window” of cached frames in the current playback direction (forward or backward). When paused, it continues to fill that same window; when seeking, it resets to cache around the new position.

Definition at line 38 of file VideoCacheThread.h.

Constructor & Destructor Documentation

◆ VideoCacheThread()

openshot::VideoCacheThread::VideoCacheThread ( )

Constructor: initializes member variables and assumes forward direction on first launch.

Definition at line 26 of file VideoCacheThread.cpp.

◆ ~VideoCacheThread()

openshot::VideoCacheThread::~VideoCacheThread ( )

override

Definition at line 49 of file VideoCacheThread.cpp.

Member Function Documentation

◆ AcknowledgeAudioCacheMiss()

void openshot::VideoCacheThread::AcknowledgeAudioCacheMiss ( )

inline

Definition at line 50 of file VideoCacheThread.h.

◆ acknowledgeRequest()

void openshot::VideoCacheThread::acknowledgeRequest ( int64_t started_us )

protected

Definition at line 155 of file VideoCacheThread.cpp.

Referenced by Seek(), and Stop().

◆ CancellationAcknowledgementUs()

int64_t openshot::VideoCacheThread::CancellationAcknowledgementUs ( ) const

inline

Definition at line 92 of file VideoCacheThread.h.

◆ clampToTimelineRange()

int64_t openshot::VideoCacheThread::clampToTimelineRange	(	int64_t	frame,
		int64_t	timeline_end
	)		const

protected

Clamp frame index to [1, timeline_end] when timeline_end is valid.

Definition at line 460 of file VideoCacheThread.cpp.

Referenced by clearCacheIfPaused(), isReady(), prefetchWindow(), run(), and Seek().

◆ clearCacheIfPaused()

bool openshot::VideoCacheThread::clearCacheIfPaused	(	int64_t	playhead,
		bool	paused,
		CacheBase *	cache
	)

protected

When paused and playhead is outside current cache, clear all frames.

Parameters

playhead	Current requested_display_frame
paused	True if speed == 0
cache	Pointer to CacheBase

Returns: True if ClearAllCache() was invoked.

Definition at line 468 of file VideoCacheThread.cpp.

◆ computeDirection()

int openshot::VideoCacheThread::computeDirection ( ) const

protected

Returns: Effective playback direction (+1 forward, –1 backward), preserving last_dir if speed == 0.

Definition at line 396 of file VideoCacheThread.cpp.

Referenced by isReady(), Reader(), run(), Seek(), and setSpeed().

◆ computePrerollFrames()

int64_t openshot::VideoCacheThread::computePrerollFrames ( const Settings * settings ) const

protected

Compute preroll frame count from settings.

Definition at line 429 of file VideoCacheThread.cpp.

Referenced by run().

◆ computeWindowBounds()

void openshot::VideoCacheThread::computeWindowBounds	(	int64_t	playhead,
		int	dir,
		int64_t	ahead_count,
		int64_t	timeline_end,
		int64_t &	window_begin,
		int64_t &	window_end
	)		const

protected

Compute the “window” of frames to cache around playhead.

Parameters

	playhead	Current requested_display_frame
	dir	Effective direction (±1)
	ahead_count	Number of frames ahead/back to cache
	timeline_end	Last valid frame index
[out]	window_begin	Lower bound (inclusive) of caching window
[out]	window_end	Upper bound (inclusive) of caching window

If dir > 0: window = [playhead ... playhead + ahead_count] If dir < 0: window = [playhead – ahead_count ... playhead] Always clamps to [1 ... timeline_end].

Definition at line 488 of file VideoCacheThread.cpp.

Referenced by run().

◆ EnableRequestDiagnostics()

void openshot::VideoCacheThread::EnableRequestDiagnostics ( bool enabled )

inline

Optional request timings in microseconds (zero until observed). No per-frame logging; clocks are sampled only when enabled.

Definition at line 91 of file VideoCacheThread.h.

◆ FirstCurrentFrameUs()

int64_t openshot::VideoCacheThread::FirstCurrentFrameUs ( ) const

inline

Definition at line 94 of file VideoCacheThread.h.

◆ getBytes()

int64_t openshot::VideoCacheThread::getBytes	(	int	width,
		int	height,
		int	sample_rate,
		int	channels,
		float	fps
	)

protected

Estimate memory usage for a single frame (video + audio).

Parameters

width	Frame width (pixels)
height	Frame height (pixels)
sample_rate	Audio sample rate (e.g. 48000)
channels	Number of audio channels
fps	Frames per second

Returns: Approximate size in bytes for one frame

Definition at line 136 of file VideoCacheThread.cpp.

Referenced by run().

◆ getSpeed()

int openshot::VideoCacheThread::getSpeed ( ) const

inline

Returns: The current speed (1=normal, 2=fast, –1=rewind, etc.)

Definition at line 68 of file VideoCacheThread.h.

◆ handleUserSeek()

void openshot::VideoCacheThread::handleUserSeek	(	int64_t	playhead,
		int	dir
	)

protected

If userSeeked is true, reset last_cached_index just behind the playhead.

Parameters

playhead	Current requested_display_frame
dir	Effective direction (±1)

Definition at line 406 of file VideoCacheThread.cpp.

Referenced by run().

◆ handleUserSeekWithPreroll()

void openshot::VideoCacheThread::handleUserSeekWithPreroll	(	int64_t	playhead,
		int	dir,
		int64_t	timeline_end,
		int64_t	preroll_frames
	)

protected

Reset last_cached_index to start caching with a directional preroll offset.

Parameters

playhead	Current requested_display_frame
dir	Effective direction (±1)
timeline_end	Last valid frame index
preroll_frames	Number of frames to offset the cache start

Definition at line 412 of file VideoCacheThread.cpp.

Referenced by run().

◆ isReady()

bool openshot::VideoCacheThread::isReady ( )

Shared startup gate; bounded fallback resumes established video decoding.

Definition at line 56 of file VideoCacheThread.cpp.

Referenced by openshot::AudioReaderSource::getNextAudioBlock().

◆ monotonicUs()

int64_t openshot::VideoCacheThread::monotonicUs ( )

staticprotected

Definition at line 149 of file VideoCacheThread.cpp.

Referenced by acknowledgeRequest(), isReady(), prefetchWindow(), resetReadiness(), Seek(), and Stop().

◆ NotifyAudioCacheMiss()

void openshot::VideoCacheThread::NotifyAudioCacheMiss ( )

inline

Definition at line 49 of file VideoCacheThread.h.

Referenced by openshot::AudioReaderSource::getNextAudioBlock().

◆ NotifyPlaybackPosition()

void openshot::VideoCacheThread::NotifyPlaybackPosition ( int64_t new_position )

Update playback position without triggering seek behavior or cache invalidation.

Definition at line 376 of file VideoCacheThread.cpp.

Referenced by Seek().

◆ ObsoleteCompletionUs()

int64_t openshot::VideoCacheThread::ObsoleteCompletionUs ( ) const

inline

Definition at line 93 of file VideoCacheThread.h.

◆ Play()

void openshot::VideoCacheThread::Play ( )

inline

Play method is unimplemented.

Definition at line 53 of file VideoCacheThread.h.

◆ prefetchWindow()

bool openshot::VideoCacheThread::prefetchWindow	(	CacheBase *	cache,
		int64_t	window_begin,
		int64_t	window_end,
		int	dir,
		ReaderBase *	reader,
		int64_t	max_frames_to_fetch = `-1`,
		uint64_t	generation = `UINT64_MAX`
	)

protected

Prefetch all missing frames in [window_begin ... window_end] or [window_end ... window_begin].

Parameters

cache	Pointer to CacheBase
window_begin	Inclusive lower bound of the window
window_end	Inclusive upper bound of the window
dir	Effective direction (±1)
reader	Pointer to ReaderBase to call GetFrame()

Returns: True if the window was already full (no new frames added)

Internally, this method iterates from last_cached_index + dir toward window_end (or window_begin) and calls GetFrame()/Add() for each missing frame until hitting the window boundary or an OOB. It also breaks early if threadShouldExit() or userSeeked becomes true.

Definition at line 510 of file VideoCacheThread.cpp.

Referenced by run().

◆ Reader()

void openshot::VideoCacheThread::Reader ( ReaderBase * new_reader )

Attach a ReaderBase (e.g. Timeline, FFmpegReader) and begin caching.

Parameters

new_reader

Definition at line 195 of file VideoCacheThread.cpp.

Referenced by openshot::QtPlayer::Reader().

◆ resetReadiness()

void openshot::VideoCacheThread::resetReadiness ( )

protected

Definition at line 94 of file VideoCacheThread.cpp.

Referenced by isReady(), Reader(), run(), Seek(), and setSpeed().

◆ resolveTimelineEnd()

int64_t openshot::VideoCacheThread::resolveTimelineEnd ( ) const

protected

Resolve timeline end frame from reader/timeline metadata.

Definition at line 445 of file VideoCacheThread.cpp.

Referenced by clearCacheIfPaused(), prefetchWindow(), run(), and Seek().

◆ run()

void openshot::VideoCacheThread::run ( )

overrideprotected

Thread entry point: loops until threadShouldExit() is true.

Definition at line 604 of file VideoCacheThread.cpp.

◆ Seek() [1/2]

void openshot::VideoCacheThread::Seek ( int64_t new_position )

Backward-compatible alias for playback position updates (no seek side effects).

Definition at line 371 of file VideoCacheThread.cpp.

Referenced by openshot::QtPlayer::Seek().

◆ Seek() [2/2]

void openshot::VideoCacheThread::Seek	(	int64_t	new_position,
		bool	start_preroll
	)

Seek to a specific frame and optionally start a preroll (cache reset).

Parameters

new_position	Frame index to jump to.
start_preroll	If true, forces cache to rebuild around new_position.

Definition at line 219 of file VideoCacheThread.cpp.

◆ setSpeed()

void openshot::VideoCacheThread::setSpeed ( int new_speed )

Set playback speed/direction. Positive = forward, negative = rewind, zero = pause.

Parameters

new_speed

If new_speed != 0, last_speed and last_dir are updated. If new_speed == 0, last_dir is left unchanged so that pausing does not flip direction.

Definition at line 112 of file VideoCacheThread.cpp.

Referenced by openshot::QtPlayer::Speed().

◆ StartThread()

bool openshot::VideoCacheThread::StartThread ( )

Start the cache thread at high priority. Returns true if it’s actually running.

Definition at line 167 of file VideoCacheThread.cpp.

◆ Stop()

void openshot::VideoCacheThread::Stop ( )

Stop method is unimplemented.

Definition at line 177 of file VideoCacheThread.cpp.

Referenced by Reader(), openshot::QtPlayer::Stop(), and StopThread().

◆ StopThread()

bool openshot::VideoCacheThread::StopThread ( int timeoutMs = 0 )

Stop the cache thread (wait up to timeoutMs ms). Returns true if it stopped.

Definition at line 186 of file VideoCacheThread.cpp.

Referenced by ~VideoCacheThread().

◆ updateReadiness()

void openshot::VideoCacheThread::updateReadiness	(	CacheBase *	cache,
		int64_t	playhead,
		int	dir
	)

protected

Worker-only cache probing; never runs in the audio callback.

Definition at line 100 of file VideoCacheThread.cpp.

Referenced by prefetchWindow(), run(), and Seek().

◆ UsesCachedAudio()

bool openshot::VideoCacheThread::UsesCachedAudio ( ) const

inline

Callback miss holds the shared gate until the player resynchronizes audio.

Definition at line 48 of file VideoCacheThread.h.

Referenced by openshot::AudioReaderSource::getNextAudioBlock().

Member Data Documentation

◆ acknowledgement_us

std::atomic<int64_t> openshot::VideoCacheThread::acknowledgement_us {0}

protected

Definition at line 248 of file VideoCacheThread.h.

Referenced by acknowledgeRequest(), and CancellationAcknowledgementUs().

◆ audio_cache_miss

std::atomic<bool> openshot::VideoCacheThread::audio_cache_miss {false}

protected

Definition at line 208 of file VideoCacheThread.h.

Referenced by AcknowledgeAudioCacheMiss(), isReady(), NotifyAudioCacheMiss(), and Reader().

◆ cache_audio_only

std::atomic<bool> openshot::VideoCacheThread::cache_audio_only {false}

protected

Definition at line 209 of file VideoCacheThread.h.

Referenced by Reader(), run(), and UsesCachedAudio().

◆ cached_frame_count

std::atomic<int64_t> openshot::VideoCacheThread::cached_frame_count

protected

Estimated count of frames currently stored in cache.

Definition at line 233 of file VideoCacheThread.h.

Referenced by clearCacheIfPaused(), NotifyPlaybackPosition(), prefetchWindow(), run(), and Seek().

◆ clear_cache_on_next_fill

std::atomic<bool> openshot::VideoCacheThread::clear_cache_on_next_fill

protected

True if next cache loop should clear existing cache ranges.

Definition at line 228 of file VideoCacheThread.h.

Referenced by run(), and Seek().

◆ contiguous_ahead

int64_t openshot::VideoCacheThread::contiguous_ahead = 0

protected

Definition at line 205 of file VideoCacheThread.h.

Referenced by isReady(), resetReadiness(), run(), and updateReadiness().

◆ current_display_frame

int64_t openshot::VideoCacheThread::current_display_frame

protected

Currently displayed frame (unused here, reserved).

Definition at line 232 of file VideoCacheThread.h.

◆ diagnostics_enabled

std::atomic<bool> openshot::VideoCacheThread::diagnostics_enabled {false}

protected

Definition at line 246 of file VideoCacheThread.h.

Referenced by EnableRequestDiagnostics(), prefetchWindow(), Seek(), and Stop().

◆ first_current_frame_us

std::atomic<int64_t> openshot::VideoCacheThread::first_current_frame_us {0}

protected

Definition at line 250 of file VideoCacheThread.h.

Referenced by acknowledgeRequest(), FirstCurrentFrameUs(), and prefetchWindow().

◆ force_directional_cache

bool openshot::VideoCacheThread::force_directional_cache

protected

(Reserved for future use).

Definition at line 239 of file VideoCacheThread.h.

◆ last_cached_frame

std::shared_ptr<Frame> openshot::VideoCacheThread::last_cached_frame

protected

Last frame pointer added to cache.

Definition at line 221 of file VideoCacheThread.h.

◆ last_cached_index

std::atomic<int64_t> openshot::VideoCacheThread::last_cached_index

protected

Index of the most recently cached frame.

Definition at line 243 of file VideoCacheThread.h.

Referenced by handleUserSeek(), handleUserSeekWithPreroll(), prefetchWindow(), Reader(), run(), Seek(), and setSpeed().

◆ last_dir

std::atomic<int> openshot::VideoCacheThread::last_dir

protected

Last direction sign (+1 forward, –1 backward).

Definition at line 225 of file VideoCacheThread.h.

Referenced by computeDirection(), and setSpeed().

◆ last_speed

std::atomic<int> openshot::VideoCacheThread::last_speed

protected

Last non-zero speed (for tracking).

Definition at line 224 of file VideoCacheThread.h.

Referenced by setSpeed().

◆ lifecycle_mutex

std::mutex openshot::VideoCacheThread::lifecycle_mutex

mutableprotected

Start/stop/reader drain; never acquired by worker.

Definition at line 253 of file VideoCacheThread.h.

Referenced by Reader(), StartThread(), and StopThread().

◆ min_frames_ahead

std::atomic<int64_t> openshot::VideoCacheThread::min_frames_ahead

protected

Minimum number of frames considered “ready” (pre-roll).

Definition at line 235 of file VideoCacheThread.h.

Referenced by isReady(), prefetchWindow(), run(), and updateReadiness().

◆ observed_frame_bytes

int64_t openshot::VideoCacheThread::observed_frame_bytes = 0

protected

Definition at line 210 of file VideoCacheThread.h.

Referenced by prefetchWindow(), and run().

◆ obsolete_completion_us

std::atomic<int64_t> openshot::VideoCacheThread::obsolete_completion_us {0}

protected

Definition at line 249 of file VideoCacheThread.h.

Referenced by acknowledgeRequest(), ObsoleteCompletionUs(), and prefetchWindow().

◆ preroll_on_next_fill

std::atomic<bool> openshot::VideoCacheThread::preroll_on_next_fill

protected

True if next cache rebuild should include preroll offset.

Definition at line 227 of file VideoCacheThread.h.

Referenced by run(), and Seek().

◆ preroll_policy

AdaptivePreroll openshot::VideoCacheThread::preroll_policy

protected

Definition at line 204 of file VideoCacheThread.h.

Referenced by isReady(), prefetchWindow(), resetReadiness(), and run().

◆ processed_generation

std::atomic<uint64_t> openshot::VideoCacheThread::processed_generation {UINT64_MAX}

protected

Last request whose scheduling baseline was consumed.

Definition at line 244 of file VideoCacheThread.h.

Referenced by isReady(), and run().

◆ reader

ReaderBase* openshot::VideoCacheThread::reader

protected

The source reader (e.g., Timeline, FFmpegReader).

Definition at line 238 of file VideoCacheThread.h.

Referenced by clearCacheIfPaused(), isReady(), NotifyPlaybackPosition(), prefetchWindow(), Reader(), resolveTimelineEnd(), run(), and Seek().

◆ readiness_bytes_per_frame

int64_t openshot::VideoCacheThread::readiness_bytes_per_frame = 0

protected

Definition at line 214 of file VideoCacheThread.h.

Referenced by run().

◆ readiness_capacity

int64_t openshot::VideoCacheThread::readiness_capacity = 0

protected

Definition at line 211 of file VideoCacheThread.h.

Referenced by prefetchWindow(), and run().

◆ readiness_direction

int openshot::VideoCacheThread::readiness_direction = 1

protected

Definition at line 207 of file VideoCacheThread.h.

Referenced by isReady(), and updateReadiness().

◆ readiness_epoch

uint64_t openshot::VideoCacheThread::readiness_epoch = 0

protected

Definition at line 215 of file VideoCacheThread.h.

Referenced by isReady(), run(), and Seek().

◆ readiness_generation

uint64_t openshot::VideoCacheThread::readiness_generation = UINT64_MAX

protected

Request covered by the readiness snapshot.

Definition at line 216 of file VideoCacheThread.h.

Referenced by isReady(), and updateReadiness().

◆ readiness_minimum_step

int64_t openshot::VideoCacheThread::readiness_minimum_step = 0

protected

Definition at line 217 of file VideoCacheThread.h.

Referenced by isReady(), run(), and updateReadiness().

◆ readiness_physical_capacity

int64_t openshot::VideoCacheThread::readiness_physical_capacity = 0

protected

Definition at line 212 of file VideoCacheThread.h.

Referenced by isReady(), run(), and Seek().

◆ readiness_playhead

int64_t openshot::VideoCacheThread::readiness_playhead = 1

protected

Definition at line 206 of file VideoCacheThread.h.

Referenced by isReady(), and updateReadiness().

◆ readiness_timeline_end

int64_t openshot::VideoCacheThread::readiness_timeline_end = 0

protected

Definition at line 213 of file VideoCacheThread.h.

Referenced by isReady(), and run().

◆ request_generation

std::atomic<uint64_t> openshot::VideoCacheThread::request_generation {0}

protected

Invalidates obsolete fills, including seeks retaining cache.

Definition at line 245 of file VideoCacheThread.h.

Referenced by acknowledgeRequest(), isReady(), prefetchWindow(), Reader(), run(), setSpeed(), and updateReadiness().

◆ request_time_us

std::atomic<int64_t> openshot::VideoCacheThread::request_time_us {0}

protected

Definition at line 247 of file VideoCacheThread.h.

Referenced by acknowledgeRequest(), and prefetchWindow().

◆ requested_display_frame

std::atomic<int64_t> openshot::VideoCacheThread::requested_display_frame

protected

Frame index the user requested.

Definition at line 231 of file VideoCacheThread.h.

Referenced by isReady(), NotifyPlaybackPosition(), prefetchWindow(), Reader(), run(), Seek(), and setSpeed().

◆ scrub_active

std::atomic<bool> openshot::VideoCacheThread::scrub_active

protected

True while user is dragging/scrubbing the playhead.

Definition at line 229 of file VideoCacheThread.h.

Referenced by NotifyPlaybackPosition(), run(), Seek(), and setSpeed().

◆ seek_state_mutex

std::mutex openshot::VideoCacheThread::seek_state_mutex

mutableprotected

Protects coherent seek state updates/consumption.

Definition at line 254 of file VideoCacheThread.h.

Referenced by isReady(), NotifyPlaybackPosition(), prefetchWindow(), Reader(), run(), Seek(), setSpeed(), and Stop().

◆ seen_timeline_cache_epoch

uint64_t openshot::VideoCacheThread::seen_timeline_cache_epoch

protected

Last observed Timeline cache invalidation epoch.

Definition at line 240 of file VideoCacheThread.h.

Referenced by Reader(), and run().

◆ speed

std::atomic<int> openshot::VideoCacheThread::speed

protected

Current playback speed (0=paused, >0 forward, <0 backward).

Definition at line 223 of file VideoCacheThread.h.

Referenced by computeDirection(), getSpeed(), prefetchWindow(), run(), Seek(), and setSpeed().

◆ timeline_cache_epoch_initialized

bool openshot::VideoCacheThread::timeline_cache_epoch_initialized

protected

True once an initial epoch snapshot has been taken.

Definition at line 241 of file VideoCacheThread.h.

Referenced by Reader(), and run().

◆ timeline_max_frame

int64_t openshot::VideoCacheThread::timeline_max_frame

protected

Highest valid frame index in the timeline.

Definition at line 236 of file VideoCacheThread.h.

◆ userSeeked

std::atomic<bool> openshot::VideoCacheThread::userSeeked

protected

True if Seek(..., true) was called (forces a cache reset).

Definition at line 226 of file VideoCacheThread.h.

Referenced by prefetchWindow(), Reader(), run(), Seek(), and setSpeed().

The documentation for this class was generated from the following files:

Qt/VideoCacheThread.h
Qt/VideoCacheThread.cpp

Public Member Functions

Protected Member Functions

Static Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ VideoCacheThread()

◆ ~VideoCacheThread()

Member Function Documentation

◆ AcknowledgeAudioCacheMiss()

◆ acknowledgeRequest()

◆ CancellationAcknowledgementUs()

◆ clampToTimelineRange()

◆ clearCacheIfPaused()

◆ computeDirection()

◆ computePrerollFrames()

◆ computeWindowBounds()

◆ EnableRequestDiagnostics()

◆ FirstCurrentFrameUs()

◆ getBytes()

◆ getSpeed()

◆ handleUserSeek()

◆ handleUserSeekWithPreroll()

◆ isReady()

◆ monotonicUs()

◆ NotifyAudioCacheMiss()

◆ NotifyPlaybackPosition()

◆ ObsoleteCompletionUs()

◆ Play()

◆ prefetchWindow()

◆ Reader()

◆ resetReadiness()

◆ resolveTimelineEnd()

◆ run()

◆ Seek() [1/2]

◆ Seek() [2/2]

◆ setSpeed()

◆ StartThread()

◆ Stop()

◆ StopThread()

◆ updateReadiness()

◆ UsesCachedAudio()

Member Data Documentation

◆ acknowledgement_us

◆ audio_cache_miss

◆ cache_audio_only

◆ cached_frame_count

◆ clear_cache_on_next_fill

◆ contiguous_ahead

◆ current_display_frame

◆ diagnostics_enabled

◆ first_current_frame_us

◆ force_directional_cache

◆ last_cached_frame

◆ last_cached_index

◆ last_dir

◆ last_speed

◆ lifecycle_mutex

◆ min_frames_ahead

◆ observed_frame_bytes

◆ obsolete_completion_us

◆ preroll_on_next_fill

◆ preroll_policy

◆ processed_generation

◆ reader

◆ readiness_bytes_per_frame

◆ readiness_capacity

◆ readiness_direction

◆ readiness_epoch

◆ readiness_generation

◆ readiness_minimum_step

◆ readiness_physical_capacity

◆ readiness_playhead

◆ readiness_timeline_end

◆ request_generation

◆ request_time_us

◆ requested_display_frame

◆ scrub_active

◆ seek_state_mutex

◆ seen_timeline_cache_epoch