streaming::FfmpegStreamBackend Class Reference

Owns the FFmpeg decode and SDL presentation state for one stream. More...

#include <src/streaming/ffmpeg_stream_backend.h>

Public Member Functions
std::string	build_overlay_status_line () const
	Build a short user-visible media status line.
void	cleanup_audio_decoder ()
	Clean up all FFmpeg audio decode resources.
void	cleanup_video_decoder ()
	Clean up all FFmpeg video decode resources.
void	decode_and_play_audio_sample (const char *sampleData, int sampleLength)
	Decode and queue one Moonlight Opus audio payload.
bool	ensure_audio_resampler ()
	Ensure the audio resampler matches the current decoded frame.
	FfmpegStreamBackend ()=default
	Construct an empty backend.
	FfmpegStreamBackend (const FfmpegStreamBackend &)=delete
bool	has_decoded_video () const
	Report whether at least one decoded video frame is available.
bool	has_unrendered_video_frame () const
	Report whether a newly decoded video frame has not been presented yet.
int	initialize_audio_decoder (int audioConfiguration, const OPUS_MULTISTREAM_CONFIGURATION *opusConfig, int arFlags)
	Initialize the FFmpeg Opus decoder and SDL playback device.
void	initialize_callbacks (DECODER_RENDERER_CALLBACKS *videoCallbacks, AUDIO_RENDERER_CALLBACKS *audioCallbacks) const
	Populate Moonlight callback tables for this backend.
std::uint64_t	milliseconds_since_last_decoded_video_frame (std::uint64_t nowMicroseconds) const
	Return how long it has been since FFmpeg published a decoded video frame.
FfmpegStreamBackend &	operator= (const FfmpegStreamBackend &)=delete
bool	render_latest_video_frame (SDL_Renderer *renderer, int screenWidth, int screenHeight, bool allowDirectFramebuffer=true)
	Render the latest decoded video frame to the supplied renderer.
void	set_audio_playback_enabled (bool enabled)
	Configure whether streamed audio should be decoded and played locally.
int	setup_video_decoder (int videoFormat, int width, int height, int redrawRate, int drFlags)
	Initialize the FFmpeg H.264 decoder for Moonlight video callbacks.
void	shutdown ()
	Release all FFmpeg, SDL, and cached frame resources.
void	start_audio_playback ()
	Start SDL audio playback.
void	start_video_decoder ()
	Start the video decode path.
void	stop_audio_playback ()
	Stop SDL audio playback.
void	stop_video_decoder ()
	Stop the video decode path.
	~FfmpegStreamBackend ()
	Destroy the backend and release all resources.

Detailed Description

Owns the FFmpeg decode and SDL presentation state for one stream.

The backend exposes Moonlight-compatible callback tables for video and audio, decodes H.264 video and Opus stereo audio with FFmpeg, presents the most recent decoded frame through SDL, and queues decoded PCM samples to SDL audio.

Member Function Documentation

build_overlay_status_line()

std::string streaming::FfmpegStreamBackend::build_overlay_status_line

(

)

const

Build a short user-visible media status line.

Returns

Summary of decoded video and queued audio state.

decode_and_play_audio_sample()

void streaming::FfmpegStreamBackend::decode_and_play_audio_sample	(	const char *	sampleData,
		int	sampleLength )

Decode and queue one Moonlight Opus audio payload.

Parameters

sampleData	Encoded Opus payload.
sampleLength	Encoded payload size in bytes.

ensure_audio_resampler()

bool streaming::FfmpegStreamBackend::ensure_audio_resampler

(

)

Ensure the audio resampler matches the current decoded frame.

Returns

True when the resampler is ready for audio conversion.

has_decoded_video()

bool streaming::FfmpegStreamBackend::has_decoded_video

(

)

const

Report whether at least one decoded video frame is available.

Returns

True when a decoded frame is ready for presentation.

has_unrendered_video_frame()

bool streaming::FfmpegStreamBackend::has_unrendered_video_frame

(

)

const

Report whether a newly decoded video frame has not been presented yet.

Returns

True when rendering would present a newer decoded frame.

initialize_audio_decoder()

int streaming::FfmpegStreamBackend::initialize_audio_decoder	(	int	audioConfiguration,
		const OPUS_MULTISTREAM_CONFIGURATION *	opusConfig,
		int	arFlags )

Initialize the FFmpeg Opus decoder and SDL playback device.

Parameters

audioConfiguration	Negotiated Moonlight audio configuration.
opusConfig	Negotiated Opus multistream parameters.
arFlags	Moonlight audio renderer flags.

Returns

Zero on success.

initialize_callbacks()

void streaming::FfmpegStreamBackend::initialize_callbacks	(	DECODER_RENDERER_CALLBACKS *	videoCallbacks,
		AUDIO_RENDERER_CALLBACKS *	audioCallbacks ) const

Populate Moonlight callback tables for this backend.

Parameters

videoCallbacks	Output video callback table.
audioCallbacks	Output audio callback table.

milliseconds_since_last_decoded_video_frame()

std::uint64_t streaming::FfmpegStreamBackend::milliseconds_since_last_decoded_video_frame

(

std::uint64_t

nowMicroseconds

)

const

Return how long it has been since FFmpeg published a decoded video frame.

Parameters

nowMicroseconds

Current platform monotonic time.

Returns

Milliseconds since the last decoded frame, or zero before a frame is published.

render_latest_video_frame()

bool streaming::FfmpegStreamBackend::render_latest_video_frame	(	SDL_Renderer *	renderer,
		int	screenWidth,
		int	screenHeight,
		bool	allowDirectFramebuffer = true )

Render the latest decoded video frame to the supplied renderer.

Parameters

renderer	SDL renderer used by the stream session.
screenWidth	Current renderer output width.
screenHeight	Current renderer output height.
allowDirectFramebuffer	True when platform-specific direct presentation may bypass SDL's renderer.

Returns

True when a decoded frame was available and rendered.

set_audio_playback_enabled()

void streaming::FfmpegStreamBackend::set_audio_playback_enabled

(

bool

enabled

)

Configure whether streamed audio should be decoded and played locally.

Parameters

enabled

True to decode and play Opus audio on the Xbox.

setup_video_decoder()

int streaming::FfmpegStreamBackend::setup_video_decoder	(	int	videoFormat,
		int	width,
		int	height,
		int	redrawRate,
		int	drFlags )

Initialize the FFmpeg H.264 decoder for Moonlight video callbacks.

Parameters

videoFormat	Negotiated Moonlight video format.
width	Negotiated stream width.
height	Negotiated stream height.
redrawRate	Negotiated redraw rate.
drFlags	Moonlight decoder flags.

Returns

Zero on success.

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

• src/streaming/ffmpeg_stream_backend.h
• src/streaming/ffmpeg_stream_backend.cpp