Source repositoryaudio.h File Reference

Declarations for audio capture and encoding. More...

#include "platform/common.h"
#include "thread_safe.h"
#include "utility.h"
#include <array>
#include <bitset>
#include <string_view>
#include <vector>

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Classes
struct	audio::audio_ctx_t
	Shared audio device state used while streams are active. More...
struct	audio::config_t
	Audio capture and encoder settings for a stream. More...
struct	audio::opus_stream_config_t
	Static Opus encoder layout for one advertised audio mode. More...
struct	audio::stream_params_t
	Custom Opus channel layout supplied by configuration. More...

Typedefs
using	audio::audio_ctx_ref_t = safe::shared_t<audio_ctx_t>::ptr_t
	Shared mailbox reference to the global audio context.
using	audio::buffer_t = util::buffer_t<std::uint8_t>
	Byte buffer used for encoded audio packet payloads.
using	audio::packet_t = std::pair<stream::session_t *, buffer_t>
	Encoded audio packet paired with its owning stream session.

Enumerations
enum class	audio::dolby_codec_e { opus , ac3 , eac3 }
	Audio codec selected by RTSP Dolby offer/accept negotiation. More...
enum	audio::stream_config_e : int {   audio::STEREO , audio::HIGH_STEREO , audio::SURROUND51 , audio::HIGH_SURROUND51 ,   audio::SURROUND71 , audio::HIGH_SURROUND71 , audio::MAX_STREAM_CONFIG }
	Supported Opus channel layouts advertised to Moonlight clients. More...

Functions
bool	audio::ac3_available ()
	Check whether the linked FFmpeg build provides the AC-3 encoder.
void	audio::capture (safe::mail_t mail, config_t config, stream::session_t *channel_data)
	Run the capture loop for this backend.
dolby_codec_e	audio::configure_dolby_audio (config_t &config, std::string_view offered, std::string_view accepted, bool ac3_encoder_available, bool eac3_encoder_available, bool high_quality)
	Configure a Dolby stream only for an exact, supported client acceptance.
int	audio::dolby_bitrate_kbps (bool eac3, bool high_quality, int channels)
	Select a channel-aware bitrate for Dolby audio encoding.
std::string_view	audio::dolby_codec_name (dolby_codec_e codec)
	Return the codec label for the RTSP audio-codec response header.
bool	audio::eac3_available ()
	Check whether the linked FFmpeg build provides the E-AC-3 encoder.
audio_ctx_ref_t	audio::get_audio_ctx_ref ()
	Get the reference to the audio context.
bool	audio::is_audio_ctx_sink_available (const audio_ctx_t &ctx)
	Check if the audio sink held by audio context is available.

Detailed Description

Declarations for audio capture and encoding.

Enumeration Type Documentation

dolby_codec_e

enum class audio::dolby_codec_e

strong

Audio codec selected by RTSP Dolby offer/accept negotiation.

Enumerator
opus	Existing Opus audio path.
ac3	Dolby Digital AC-3 bitstream.
eac3	Dolby Digital Plus E-AC-3 bitstream.

stream_config_e

enum audio::stream_config_e : int

Supported Opus channel layouts advertised to Moonlight clients.

Enumerator
STEREO	Stereo.
HIGH_STEREO	High stereo.
SURROUND51	Surround 5.1.
HIGH_SURROUND51	High surround 5.1.
SURROUND71	Surround 7.1.
HIGH_SURROUND71	High surround 7.1.
MAX_STREAM_CONFIG	Maximum audio stream configuration.

Function Documentation

ac3_available()

bool audio::ac3_available

(

)

Check whether the linked FFmpeg build provides the AC-3 encoder.

Check whether a compatible optional FFmpeg AC-3 encoder is available.

Returns

True when the AC-3 encoder is available in this build.

True when the required FFmpeg DLLs and AC-3 encoder are available.

capture()

void audio::capture	(	safe::mail_t	mail,
		config_t	config,
		stream::session_t *	channel_data )

Run the capture loop for this backend.

Capture, encode, and publish audio packets for a stream.

Parameters

mail	Mailbox used to publish encoded audio packets.
config	Audio capture and encoder settings.
channel_data	Stream session that receives the encoded packets.

configure_dolby_audio()

dolby_codec_e audio::configure_dolby_audio	(	config_t &	config,
		std::string_view	offered,
		std::string_view	accepted,
		bool	ac3_encoder_available,
		bool	eac3_encoder_available,
		bool	high_quality )

Configure a Dolby stream only for an exact, supported client acceptance.

Parameters

config	Audio configuration to update for the negotiated stream.
offered	Codec offered by Sunshine, or empty when using Opus.
accepted	Codec explicitly accepted by the client.
ac3_encoder_available	Whether the AC-3 encoder is available.
eac3_encoder_available	Whether the E-AC-3 encoder is available.
high_quality	Whether the higher Dolby bitrate was requested.

Returns

Selected codec, falling back to Opus when negotiation is unsupported.

dolby_bitrate_kbps()

int audio::dolby_bitrate_kbps	(	bool	eac3,
		bool	high_quality,
		int	channels )

Select a channel-aware bitrate for Dolby audio encoding.

Parameters

eac3	True to select E-AC-3; false to select AC-3.
high_quality	Whether to use the higher Dolby bitrate.
channels	Number of output audio channels (stereo or 5.1).

Returns

The selected bitrate in kbit/s, or 0 for unsupported channel layouts.

dolby_codec_name()

std::string_view audio::dolby_codec_name

(

dolby_codec_e

codec

)

Return the codec label for the RTSP audio-codec response header.

Parameters

codec

Selected audio codec.

Returns

RTSP codec label.

eac3_available()

bool audio::eac3_available

(

)

Check whether the linked FFmpeg build provides the E-AC-3 encoder.

Check whether a compatible optional FFmpeg E-AC-3 encoder is available.

Returns

True when the E-AC-3 encoder is available in this build.

True when the required FFmpeg DLLs and E-AC-3 encoder are available.

get_audio_ctx_ref()

audio_ctx_ref_t audio::get_audio_ctx_ref

(

)

Get the reference to the audio context.

Returns

A shared pointer reference to audio context.

Note

Aside from the configuration purposes, it can be used to extend the audio sink lifetime to capture sink earlier and restore it later.

Examples

audio_ctx_ref_t audio = get_audio_ctx_ref()

is_audio_ctx_sink_available()

bool audio::is_audio_ctx_sink_available

(

const audio_ctx_t &

ctx

)

Check if the audio sink held by audio context is available.

Returns

True if available (and can probably be restored), false otherwise.

Note

Useful for delaying the release of audio context shared pointer (which tries to restore original sink).

Examples

audio_ctx_ref_t audio = get_audio_ctx_ref()
if (audio.get()) {
    return is_audio_ctx_sink_available(*audio.get());
}
return false;

Parameters

ctx	Native context object used by the operation or callback.