Source repositoryaudio.cpp File Reference

Definitions for audio control on Linux. More...

#include <algorithm>
#include <array>
#include <bitset>
#include <sstream>
#include <thread>
#include <boost/regex.hpp>
#include <pulse/error.h>
#include <pulse/pulseaudio.h>
#include <pulse/simple.h>
#include "src/config.h"
#include "src/logging.h"
#include "src/platform/common.h"
#include "src/thread_safe.h"

Include dependency graph for audio.cpp:

Classes
struct	platf::pa::add_const_helper< false, T >
	Template helper that leaves non-const inputs mutable. More...
struct	platf::pa::add_const_helper< true, T >
	Template helper that preserves constness for const inputs. More...
struct	platf::mic_attr_t
	PulseAudio recording stream and channel metadata. More...
class	platf::pa::server_t
	PulseAudio server controller that creates and removes Sunshine sinks. More...

Typedefs
template<class T>
using	platf::pa::add_const_t = typename add_const_helper<std::is_pointer_v<T>, T>::type
	PulseAudio callback info type with pointer constness normalized.
template<class T>
using	platf::pa::cb_simple_t = std::function<void(ctx_t::pointer, add_const_t<T> i)>
	Callback wrapper for PulseAudio introspection results without an end marker.
template<class T>
using	platf::pa::cb_t = std::function<void(ctx_t::pointer, add_const_t<T> i, int eol)>
	Callback wrapper for PulseAudio introspection results with an end marker.
using	platf::pa::ctx_t = util::safe_ptr<pa_context, &pa_context_unref>
	Owning pointer for a PulseAudio context.
using	platf::pa::loop_t = util::safe_ptr<pa_mainloop, &pa_mainloop_free>
	Owning pointer for a PulseAudio mainloop.
using	platf::pa::op_t = util::safe_ptr<pa_operation, &pa_operation_unref>
	Owning pointer for a PulseAudio asynchronous operation.
using	platf::pa::string_t = util::safe_ptr<char, &pa_free<char>>
	Owning pointer for PulseAudio strings allocated with pa_xmalloc.

Functions
std::unique_ptr< audio_control_t >	platf::audio_control ()
	Create the platform audio controller.
template<class T>
void	platf::pa::cb (ctx_t::pointer ctx, add_const_t< T > i, int eol, void *userdata)
	Handle PulseAudio source introspection results.
template<class T>
void	platf::pa::cb (ctx_t::pointer ctx, add_const_t< T > i, void *userdata)
	Handle PulseAudio sink-input introspection results.
void	platf::pa::cb_i (ctx_t::pointer, std::uint32_t i, void *userdata)
	Forward a PulseAudio integer callback value into a Sunshine alarm.
void	platf::pa::ctx_state_cb (ctx_t::pointer ctx, void *userdata)
	Translate PulseAudio context state changes into server events.
bool	platf::fill_canonical_channel_map (int channels, pa_channel_map &pa_map)
	Fill a PulseAudio channel map with the canonical layout for a channel count.
std::unique_ptr< mic_t >	platf::microphone (int channels, std::uint32_t sample_rate, std::uint32_t frame_size, std::string source_name)
	Create a microphone capture stream for the requested layout.
template<class T>
void	platf::pa::pa_free (T *p)
	Release memory allocated by PulseAudio.
void	platf::pa::success_cb (ctx_t::pointer, int status, void *userdata)
	Record completion of a PulseAudio asynchronous operation.
std::string	platf::to_string (const char *name, const std::uint8_t *mapping, int channels)
	Convert a PulseAudio operation result to a log string.

Variables
constexpr std::array< pa_channel_position_t, speaker::MAX_SPEAKERS >	platf::position_mapping
	PulseAudio position for each speaker::speaker_e, in speaker_e order.

Detailed Description

Definitions for audio control on Linux.

Function Documentation

audio_control()

std::unique_ptr< audio_control_t > platf::audio_control

(

)

Create the platform audio controller.

Returns

Platform audio controller, or nullptr when audio control is unavailable.

cb() [1/2]

template<class T>

void platf::pa::cb	(	ctx_t::pointer	ctx,
		add_const_t< T >	i,
		int	eol,
		void *	userdata )

Handle PulseAudio source introspection results.

Parameters

ctx	Native context object used by the operation or callback.
i	PulseAudio introspection info supplied to the callback.
eol	PulseAudio end-of-list marker.
userdata	Caller-provided pointer passed through the callback.

cb() [2/2]

template<class T>

void platf::pa::cb	(	ctx_t::pointer	ctx,
		add_const_t< T >	i,
		void *	userdata )

Handle PulseAudio sink-input introspection results.

Parameters

ctx	Native context object used by the operation or callback.
i	PulseAudio introspection info supplied to the callback.
userdata	Caller-provided pointer passed through the callback.

cb_i()

void platf::pa::cb_i	(	ctx_t::pointer	,
		std::uint32_t	i,
		void *	userdata )

Forward a PulseAudio integer callback value into a Sunshine alarm.

The PulseAudio callback signature supplies a context that is not needed to ring the alarm.

Parameters

i	Integer value returned by the PulseAudio operation.
userdata	Caller-provided pointer passed through the callback.

ctx_state_cb()

void platf::pa::ctx_state_cb	(	ctx_t::pointer	ctx,
		void *	userdata )

Translate PulseAudio context state changes into server events.

Parameters

ctx	Native context object used by the operation or callback.
userdata	Caller-provided pointer passed through the callback.

fill_canonical_channel_map()

bool platf::fill_canonical_channel_map	(	int	channels,
		pa_channel_map &	pa_map )

Fill a PulseAudio channel map with the canonical layout for a channel count.

Capture always uses the canonical layout, never the Opus channel mapping: the Opus mapping is applied by the multistream encoder and undone by the client, so applying it here too would leave the samples permuted. speaker::map_stereo, map_surround51 and map_surround71 are the identity over speaker::speaker_e, so the canonical position of channel i is position_mapping[i].

Parameters

channels	Number of audio channels in the stream.
pa_map	Channel map to fill; left untouched when channels is out of range.

Returns

true when the channel count maps onto a known speaker layout.

microphone()

std::unique_ptr< mic_t > platf::microphone	(	int	channels,
		std::uint32_t	sample_rate,
		std::uint32_t	frame_size,
		std::string	source_name )

Create a microphone capture stream for the requested layout.

Capture always uses the canonical channel layout; Opus mapping is applied by the encoder.

Parameters

channels	Number of audio channels in the stream.
sample_rate	Audio sample rate in hertz.
frame_size	Number of samples captured per audio frame.
source_name	Source name.

Returns

Microphone capture object for the requested audio layout, or nullptr on failure.

pa_free()

template<class T>

void platf::pa::pa_free

(

T *

p

)

Release memory allocated by PulseAudio.

Parameters

p	Pointer allocated by PulseAudio and released with pa_xfree.

success_cb()

void platf::pa::success_cb	(	ctx_t::pointer	,
		int	status,
		void *	userdata )

Record completion of a PulseAudio asynchronous operation.

The PulseAudio callback signature supplies a context that is not needed to report completion.

Parameters

status	Native status code returned by the platform API.
userdata	Caller-provided pointer passed through the callback.

to_string()

std::string platf::to_string	(	const char *	name,
		const std::uint8_t *	mapping,
		int	channels )

Convert a PulseAudio operation result to a log string.

Parameters

name	Human-readable name to assign.
mapping	Opus channel mapping table for the requested layout.
channels	Number of audio channels in the stream.

Returns

Value converted to string.

Variable Documentation

position_mapping

std::array<pa_channel_position_t, speaker::MAX_SPEAKERS> platf::position_mapping

constexpr

Initial value:

{
    PA_CHANNEL_POSITION_FRONT_LEFT,
    PA_CHANNEL_POSITION_FRONT_RIGHT,
    PA_CHANNEL_POSITION_FRONT_CENTER,
    PA_CHANNEL_POSITION_LFE,
    PA_CHANNEL_POSITION_REAR_LEFT,
    PA_CHANNEL_POSITION_REAR_RIGHT,
    PA_CHANNEL_POSITION_SIDE_LEFT,
    PA_CHANNEL_POSITION_SIDE_RIGHT,
  }

PulseAudio position for each speaker::speaker_e, in speaker_e order.