SSB_HighSpeed_Modem/hsmodem/soundio.h
Kurt Moraw 6adaf44425 update
2020-12-10 19:14:40 +01:00

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/*
* Copyright (c) 2015 Andrew Kelley
*
* This file is part of libsoundio, which is MIT licensed.
* See http://opensource.org/licenses/MIT
*/
#ifndef SOUNDIO_SOUNDIO_H
#define SOUNDIO_SOUNDIO_H
#include "endian.h"
#include <stdbool.h>
/// \cond
#ifdef __cplusplus
#define SOUNDIO_EXTERN_C extern "C"
#else
#define SOUNDIO_EXTERN_C
#endif
#if defined(SOUNDIO_STATIC_LIBRARY)
# define SOUNDIO_EXPORT SOUNDIO_EXTERN_C
#else
# if defined(_WIN32)
# if defined(SOUNDIO_BUILDING_LIBRARY)
# define SOUNDIO_EXPORT SOUNDIO_EXTERN_C __declspec(dllexport)
# else
# define SOUNDIO_EXPORT SOUNDIO_EXTERN_C __declspec(dllimport)
# endif
# else
# define SOUNDIO_EXPORT SOUNDIO_EXTERN_C __attribute__((visibility ("default")))
# endif
#endif
/// \endcond
/** \mainpage
*
* \section intro_sec Overview
*
* libsoundio is a C library for cross-platform audio input and output. It is
* suitable for real-time and consumer software.
*
* Documentation: soundio.h
*/
/** \example sio_list_devices.c
* List the available input and output devices on the system and their
* properties. Supports watching for changes and specifying backend to use.
*/
/** \example sio_sine.c
* Play a sine wave over the default output device.
* Supports specifying device and backend to use.
*/
/** \example sio_record.c
* Record audio to an output file.
* Supports specifying device and backend to use.
*/
/** \example sio_microphone.c
* Stream the default input device over the default output device.
* Supports specifying device and backend to use.
*/
/** \example backend_disconnect_recover.c
* Demonstrates recovering from a backend disconnecting.
*/
/// See also ::soundio_strerror
enum SoundIoError {
SoundIoErrorNone,
/// Out of memory.
SoundIoErrorNoMem,
/// The backend does not appear to be active or running.
SoundIoErrorInitAudioBackend,
/// A system resource other than memory was not available.
SoundIoErrorSystemResources,
/// Attempted to open a device and failed.
SoundIoErrorOpeningDevice,
SoundIoErrorNoSuchDevice,
/// The programmer did not comply with the API.
SoundIoErrorInvalid,
/// libsoundio was compiled without support for that backend.
SoundIoErrorBackendUnavailable,
/// An open stream had an error that can only be recovered from by
/// destroying the stream and creating it again.
SoundIoErrorStreaming,
/// Attempted to use a device with parameters it cannot support.
SoundIoErrorIncompatibleDevice,
/// When JACK returns `JackNoSuchClient`
SoundIoErrorNoSuchClient,
/// Attempted to use parameters that the backend cannot support.
SoundIoErrorIncompatibleBackend,
/// Backend server shutdown or became inactive.
SoundIoErrorBackendDisconnected,
SoundIoErrorInterrupted,
/// Buffer underrun occurred.
SoundIoErrorUnderflow,
/// Unable to convert to or from UTF-8 to the native string format.
SoundIoErrorEncodingString,
};
/// Specifies where a channel is physically located.
enum SoundIoChannelId {
SoundIoChannelIdInvalid,
SoundIoChannelIdFrontLeft, ///< First of the more commonly supported ids.
SoundIoChannelIdFrontRight,
SoundIoChannelIdFrontCenter,
SoundIoChannelIdLfe,
SoundIoChannelIdBackLeft,
SoundIoChannelIdBackRight,
SoundIoChannelIdFrontLeftCenter,
SoundIoChannelIdFrontRightCenter,
SoundIoChannelIdBackCenter,
SoundIoChannelIdSideLeft,
SoundIoChannelIdSideRight,
SoundIoChannelIdTopCenter,
SoundIoChannelIdTopFrontLeft,
SoundIoChannelIdTopFrontCenter,
SoundIoChannelIdTopFrontRight,
SoundIoChannelIdTopBackLeft,
SoundIoChannelIdTopBackCenter,
SoundIoChannelIdTopBackRight, ///< Last of the more commonly supported ids.
SoundIoChannelIdBackLeftCenter, ///< First of the less commonly supported ids.
SoundIoChannelIdBackRightCenter,
SoundIoChannelIdFrontLeftWide,
SoundIoChannelIdFrontRightWide,
SoundIoChannelIdFrontLeftHigh,
SoundIoChannelIdFrontCenterHigh,
SoundIoChannelIdFrontRightHigh,
SoundIoChannelIdTopFrontLeftCenter,
SoundIoChannelIdTopFrontRightCenter,
SoundIoChannelIdTopSideLeft,
SoundIoChannelIdTopSideRight,
SoundIoChannelIdLeftLfe,
SoundIoChannelIdRightLfe,
SoundIoChannelIdLfe2,
SoundIoChannelIdBottomCenter,
SoundIoChannelIdBottomLeftCenter,
SoundIoChannelIdBottomRightCenter,
/// Mid/side recording
SoundIoChannelIdMsMid,
SoundIoChannelIdMsSide,
/// first order ambisonic channels
SoundIoChannelIdAmbisonicW,
SoundIoChannelIdAmbisonicX,
SoundIoChannelIdAmbisonicY,
SoundIoChannelIdAmbisonicZ,
/// X-Y Recording
SoundIoChannelIdXyX,
SoundIoChannelIdXyY,
SoundIoChannelIdHeadphonesLeft, ///< First of the "other" channel ids
SoundIoChannelIdHeadphonesRight,
SoundIoChannelIdClickTrack,
SoundIoChannelIdForeignLanguage,
SoundIoChannelIdHearingImpaired,
SoundIoChannelIdNarration,
SoundIoChannelIdHaptic,
SoundIoChannelIdDialogCentricMix, ///< Last of the "other" channel ids
SoundIoChannelIdAux,
SoundIoChannelIdAux0,
SoundIoChannelIdAux1,
SoundIoChannelIdAux2,
SoundIoChannelIdAux3,
SoundIoChannelIdAux4,
SoundIoChannelIdAux5,
SoundIoChannelIdAux6,
SoundIoChannelIdAux7,
SoundIoChannelIdAux8,
SoundIoChannelIdAux9,
SoundIoChannelIdAux10,
SoundIoChannelIdAux11,
SoundIoChannelIdAux12,
SoundIoChannelIdAux13,
SoundIoChannelIdAux14,
SoundIoChannelIdAux15,
};
/// Built-in channel layouts for convenience.
enum SoundIoChannelLayoutId {
SoundIoChannelLayoutIdMono,
SoundIoChannelLayoutIdStereo,
SoundIoChannelLayoutId2Point1,
SoundIoChannelLayoutId3Point0,
SoundIoChannelLayoutId3Point0Back,
SoundIoChannelLayoutId3Point1,
SoundIoChannelLayoutId4Point0,
SoundIoChannelLayoutIdQuad,
SoundIoChannelLayoutIdQuadSide,
SoundIoChannelLayoutId4Point1,
SoundIoChannelLayoutId5Point0Back,
SoundIoChannelLayoutId5Point0Side,
SoundIoChannelLayoutId5Point1,
SoundIoChannelLayoutId5Point1Back,
SoundIoChannelLayoutId6Point0Side,
SoundIoChannelLayoutId6Point0Front,
SoundIoChannelLayoutIdHexagonal,
SoundIoChannelLayoutId6Point1,
SoundIoChannelLayoutId6Point1Back,
SoundIoChannelLayoutId6Point1Front,
SoundIoChannelLayoutId7Point0,
SoundIoChannelLayoutId7Point0Front,
SoundIoChannelLayoutId7Point1,
SoundIoChannelLayoutId7Point1Wide,
SoundIoChannelLayoutId7Point1WideBack,
SoundIoChannelLayoutIdOctagonal,
};
enum SoundIoBackend {
SoundIoBackendNone,
SoundIoBackendJack,
SoundIoBackendPulseAudio,
SoundIoBackendAlsa,
SoundIoBackendCoreAudio,
SoundIoBackendWasapi,
SoundIoBackendDummy,
};
enum SoundIoDeviceAim {
SoundIoDeviceAimInput, ///< capture / recording
SoundIoDeviceAimOutput, ///< playback
};
/// For your convenience, Native Endian and Foreign Endian constants are defined
/// which point to the respective SoundIoFormat values.
enum SoundIoFormat {
SoundIoFormatInvalid,
SoundIoFormatS8, ///< Signed 8 bit
SoundIoFormatU8, ///< Unsigned 8 bit
SoundIoFormatS16LE, ///< Signed 16 bit Little Endian
SoundIoFormatS16BE, ///< Signed 16 bit Big Endian
SoundIoFormatU16LE, ///< Unsigned 16 bit Little Endian
SoundIoFormatU16BE, ///< Unsigned 16 bit Big Endian
SoundIoFormatS24LE, ///< Signed 24 bit Little Endian using low three bytes in 32-bit word
SoundIoFormatS24BE, ///< Signed 24 bit Big Endian using low three bytes in 32-bit word
SoundIoFormatU24LE, ///< Unsigned 24 bit Little Endian using low three bytes in 32-bit word
SoundIoFormatU24BE, ///< Unsigned 24 bit Big Endian using low three bytes in 32-bit word
SoundIoFormatS32LE, ///< Signed 32 bit Little Endian
SoundIoFormatS32BE, ///< Signed 32 bit Big Endian
SoundIoFormatU32LE, ///< Unsigned 32 bit Little Endian
SoundIoFormatU32BE, ///< Unsigned 32 bit Big Endian
SoundIoFormatFloat32LE, ///< Float 32 bit Little Endian, Range -1.0 to 1.0
SoundIoFormatFloat32BE, ///< Float 32 bit Big Endian, Range -1.0 to 1.0
SoundIoFormatFloat64LE, ///< Float 64 bit Little Endian, Range -1.0 to 1.0
SoundIoFormatFloat64BE, ///< Float 64 bit Big Endian, Range -1.0 to 1.0
};
#if defined(SOUNDIO_OS_BIG_ENDIAN)
#define SoundIoFormatS16NE SoundIoFormatS16BE
#define SoundIoFormatU16NE SoundIoFormatU16BE
#define SoundIoFormatS24NE SoundIoFormatS24BE
#define SoundIoFormatU24NE SoundIoFormatU24BE
#define SoundIoFormatS32NE SoundIoFormatS32BE
#define SoundIoFormatU32NE SoundIoFormatU32BE
#define SoundIoFormatFloat32NE SoundIoFormatFloat32BE
#define SoundIoFormatFloat64NE SoundIoFormatFloat64BE
#define SoundIoFormatS16FE SoundIoFormatS16LE
#define SoundIoFormatU16FE SoundIoFormatU16LE
#define SoundIoFormatS24FE SoundIoFormatS24LE
#define SoundIoFormatU24FE SoundIoFormatU24LE
#define SoundIoFormatS32FE SoundIoFormatS32LE
#define SoundIoFormatU32FE SoundIoFormatU32LE
#define SoundIoFormatFloat32FE SoundIoFormatFloat32LE
#define SoundIoFormatFloat64FE SoundIoFormatFloat64LE
#elif defined(SOUNDIO_OS_LITTLE_ENDIAN)
/// Note that we build the documentation in Little Endian mode,
/// so all the "NE" macros in the docs point to "LE" and
/// "FE" macros point to "BE". On a Big Endian system it is the
/// other way around.
#define SoundIoFormatS16NE SoundIoFormatS16LE
#define SoundIoFormatU16NE SoundIoFormatU16LE
#define SoundIoFormatS24NE SoundIoFormatS24LE
#define SoundIoFormatU24NE SoundIoFormatU24LE
#define SoundIoFormatS32NE SoundIoFormatS32LE
#define SoundIoFormatU32NE SoundIoFormatU32LE
#define SoundIoFormatFloat32NE SoundIoFormatFloat32LE
#define SoundIoFormatFloat64NE SoundIoFormatFloat64LE
#define SoundIoFormatS16FE SoundIoFormatS16BE
#define SoundIoFormatU16FE SoundIoFormatU16BE
#define SoundIoFormatS24FE SoundIoFormatS24BE
#define SoundIoFormatU24FE SoundIoFormatU24BE
#define SoundIoFormatS32FE SoundIoFormatS32BE
#define SoundIoFormatU32FE SoundIoFormatU32BE
#define SoundIoFormatFloat32FE SoundIoFormatFloat32BE
#define SoundIoFormatFloat64FE SoundIoFormatFloat64BE
#else
#error unknown byte order
#endif
#define SOUNDIO_MAX_CHANNELS 24
/// The size of this struct is OK to use.
struct SoundIoChannelLayout {
const char *name;
int channel_count;
enum SoundIoChannelId channels[SOUNDIO_MAX_CHANNELS];
};
/// The size of this struct is OK to use.
struct SoundIoSampleRateRange {
int min;
int max;
};
/// The size of this struct is OK to use.
struct SoundIoChannelArea {
/// Base address of buffer.
char *ptr;
/// How many bytes it takes to get from the beginning of one sample to
/// the beginning of the next sample.
int step;
};
/// The size of this struct is not part of the API or ABI.
struct SoundIo {
/// Optional. Put whatever you want here. Defaults to NULL.
void *userdata;
/// Optional callback. Called when the list of devices change. Only called
/// during a call to ::soundio_flush_events or ::soundio_wait_events.
void (*on_devices_change)(struct SoundIo *);
/// Optional callback. Called when the backend disconnects. For example,
/// when the JACK server shuts down. When this happens, listing devices
/// and opening streams will always fail with
/// SoundIoErrorBackendDisconnected. This callback is only called during a
/// call to ::soundio_flush_events or ::soundio_wait_events.
/// If you do not supply a callback, the default will crash your program
/// with an error message. This callback is also called when the thread
/// that retrieves device information runs into an unrecoverable condition
/// such as running out of memory.
///
/// Possible errors:
/// * #SoundIoErrorBackendDisconnected
/// * #SoundIoErrorNoMem
/// * #SoundIoErrorSystemResources
/// * #SoundIoErrorOpeningDevice - unexpected problem accessing device
/// information
void (*on_backend_disconnect)(struct SoundIo *, int err);
/// Optional callback. Called from an unknown thread that you should not use
/// to call any soundio functions. You may use this to signal a condition
/// variable to wake up. Called when ::soundio_wait_events would be woken up.
void (*on_events_signal)(struct SoundIo *);
/// Read-only. After calling ::soundio_connect or ::soundio_connect_backend,
/// this field tells which backend is currently connected.
enum SoundIoBackend current_backend;
/// Optional: Application name.
/// PulseAudio uses this for "application name".
/// JACK uses this for `client_name`.
/// Must not contain a colon (":").
const char *app_name;
/// Optional: Real time priority warning.
/// This callback is fired when making thread real-time priority failed. By
/// default, it will print to stderr only the first time it is called
/// a message instructing the user how to configure their system to allow
/// real-time priority threads. This must be set to a function not NULL.
/// To silence the warning, assign this to a function that does nothing.
void (*emit_rtprio_warning)(void);
/// Optional: JACK info callback.
/// By default, libsoundio sets this to an empty function in order to
/// silence stdio messages from JACK. You may override the behavior by
/// setting this to `NULL` or providing your own function. This is
/// registered with JACK regardless of whether ::soundio_connect_backend
/// succeeds.
void (*jack_info_callback)(const char *msg);
/// Optional: JACK error callback.
/// See SoundIo::jack_info_callback
void (*jack_error_callback)(const char *msg);
};
/// The size of this struct is not part of the API or ABI.
struct SoundIoDevice {
/// Read-only. Set automatically.
struct SoundIo *soundio;
/// A string of bytes that uniquely identifies this device.
/// If the same physical device supports both input and output, that makes
/// one SoundIoDevice for the input and one SoundIoDevice for the output.
/// In this case, the id of each SoundIoDevice will be the same, and
/// SoundIoDevice::aim will be different. Additionally, if the device
/// supports raw mode, there may be up to four devices with the same id:
/// one for each value of SoundIoDevice::is_raw and one for each value of
/// SoundIoDevice::aim.
char *id;
/// User-friendly UTF-8 encoded text to describe the device.
char *name;
/// Tells whether this device is an input device or an output device.
enum SoundIoDeviceAim aim;
/// Channel layouts are handled similarly to SoundIoDevice::formats.
/// If this information is missing due to a SoundIoDevice::probe_error,
/// layouts will be NULL. It's OK to modify this data, for example calling
/// ::soundio_sort_channel_layouts on it.
/// Devices are guaranteed to have at least 1 channel layout.
struct SoundIoChannelLayout *layouts;
int layout_count;
/// See SoundIoDevice::current_format
struct SoundIoChannelLayout current_layout;
/// List of formats this device supports. See also
/// SoundIoDevice::current_format.
enum SoundIoFormat *formats;
/// How many formats are available in SoundIoDevice::formats.
int format_count;
/// A device is either a raw device or it is a virtual device that is
/// provided by a software mixing service such as dmix or PulseAudio (see
/// SoundIoDevice::is_raw). If it is a raw device,
/// current_format is meaningless;
/// the device has no current format until you open it. On the other hand,
/// if it is a virtual device, current_format describes the
/// destination sample format that your audio will be converted to. Or,
/// if you're the lucky first application to open the device, you might
/// cause the current_format to change to your format.
/// Generally, you want to ignore current_format and use
/// whatever format is most convenient
/// for you which is supported by the device, because when you are the only
/// application left, the mixer might decide to switch
/// current_format to yours. You can learn the supported formats via
/// formats and SoundIoDevice::format_count. If this information is missing
/// due to a probe error, formats will be `NULL`. If current_format is
/// unavailable, it will be set to #SoundIoFormatInvalid.
/// Devices are guaranteed to have at least 1 format available.
enum SoundIoFormat current_format;
/// Sample rate is the number of frames per second.
/// Sample rate is handled very similar to SoundIoDevice::formats.
/// If sample rate information is missing due to a probe error, the field
/// will be set to NULL.
/// Devices which have SoundIoDevice::probe_error set to #SoundIoErrorNone are
/// guaranteed to have at least 1 sample rate available.
struct SoundIoSampleRateRange *sample_rates;
/// How many sample rate ranges are available in
/// SoundIoDevice::sample_rates. 0 if sample rate information is missing
/// due to a probe error.
int sample_rate_count;
/// See SoundIoDevice::current_format
/// 0 if sample rate information is missing due to a probe error.
int sample_rate_current;
/// Software latency minimum in seconds. If this value is unknown or
/// irrelevant, it is set to 0.0.
/// For PulseAudio and WASAPI this value is unknown until you open a
/// stream.
double software_latency_min;
/// Software latency maximum in seconds. If this value is unknown or
/// irrelevant, it is set to 0.0.
/// For PulseAudio and WASAPI this value is unknown until you open a
/// stream.
double software_latency_max;
/// Software latency in seconds. If this value is unknown or
/// irrelevant, it is set to 0.0.
/// For PulseAudio and WASAPI this value is unknown until you open a
/// stream.
/// See SoundIoDevice::current_format
double software_latency_current;
/// Raw means that you are directly opening the hardware device and not
/// going through a proxy such as dmix, PulseAudio, or JACK. When you open a
/// raw device, other applications on the computer are not able to
/// simultaneously access the device. Raw devices do not perform automatic
/// resampling and thus tend to have fewer formats available.
bool is_raw;
/// Devices are reference counted. See ::soundio_device_ref and
/// ::soundio_device_unref.
int ref_count;
/// This is set to a SoundIoError representing the result of the device
/// probe. Ideally this will be SoundIoErrorNone in which case all the
/// fields of the device will be populated. If there is an error code here
/// then information about formats, sample rates, and channel layouts might
/// be missing.
///
/// Possible errors:
/// * #SoundIoErrorOpeningDevice
/// * #SoundIoErrorNoMem
int probe_error;
};
/// The size of this struct is not part of the API or ABI.
struct SoundIoOutStream {
/// Populated automatically when you call ::soundio_outstream_create.
struct SoundIoDevice *device;
/// Defaults to #SoundIoFormatFloat32NE, followed by the first one
/// supported.
enum SoundIoFormat format;
/// Sample rate is the number of frames per second.
/// Defaults to 48000 (and then clamped into range).
int sample_rate;
/// Defaults to Stereo, if available, followed by the first layout
/// supported.
struct SoundIoChannelLayout layout;
/// Ignoring hardware latency, this is the number of seconds it takes for
/// the last sample in a full buffer to be played.
/// After you call ::soundio_outstream_open, this value is replaced with the
/// actual software latency, as near to this value as possible.
/// On systems that support clearing the buffer, this defaults to a large
/// latency, potentially upwards of 2 seconds, with the understanding that
/// you will call ::soundio_outstream_clear_buffer when you want to reduce
/// the latency to 0. On systems that do not support clearing the buffer,
/// this defaults to a reasonable lower latency value.
///
/// On backends with high latencies (such as 2 seconds), `frame_count_min`
/// will be 0, meaning you don't have to fill the entire buffer. In this
/// case, the large buffer is there if you want it; you only have to fill
/// as much as you want. On backends like JACK, `frame_count_min` will be
/// equal to `frame_count_max` and if you don't fill that many frames, you
/// will get glitches.
///
/// If the device has unknown software latency min and max values, you may
/// still set this, but you might not get the value you requested.
/// For PulseAudio, if you set this value to non-default, it sets
/// `PA_STREAM_ADJUST_LATENCY` and is the value used for `maxlength` and
/// `tlength`.
///
/// For JACK, this value is always equal to
/// SoundIoDevice::software_latency_current of the device.
double software_latency;
/// Core Audio and WASAPI only: current output Audio Unit volume. Float, 0.0-1.0.
float volume;
/// Defaults to NULL. Put whatever you want here.
void *userdata;
/// In this callback, you call ::soundio_outstream_begin_write and
/// ::soundio_outstream_end_write as many times as necessary to write
/// at minimum `frame_count_min` frames and at maximum `frame_count_max`
/// frames. `frame_count_max` will always be greater than 0. Note that you
/// should write as many frames as you can; `frame_count_min` might be 0 and
/// you can still get a buffer underflow if you always write
/// `frame_count_min` frames.
///
/// For Dummy, ALSA, and PulseAudio, `frame_count_min` will be 0. For JACK
/// and CoreAudio `frame_count_min` will be equal to `frame_count_max`.
///
/// The code in the supplied function must be suitable for real-time
/// execution. That means that it cannot call functions that might block
/// for a long time. This includes all I/O functions (disk, TTY, network),
/// malloc, free, printf, pthread_mutex_lock, sleep, wait, poll, select,
/// pthread_join, pthread_cond_wait, etc.
void (*write_callback)(struct SoundIoOutStream *,
int frame_count_min, int frame_count_max);
/// This optional callback happens when the sound device runs out of
/// buffered audio data to play. After this occurs, the outstream waits
/// until the buffer is full to resume playback.
/// This is called from the SoundIoOutStream::write_callback thread context.
void (*underflow_callback)(struct SoundIoOutStream *);
/// Optional callback. `err` is always SoundIoErrorStreaming.
/// SoundIoErrorStreaming is an unrecoverable error. The stream is in an
/// invalid state and must be destroyed.
/// If you do not supply error_callback, the default callback will print
/// a message to stderr and then call `abort`.
/// This is called from the SoundIoOutStream::write_callback thread context.
void (*error_callback)(struct SoundIoOutStream *, int err);
/// Optional: Name of the stream. Defaults to "SoundIoOutStream"
/// PulseAudio uses this for the stream name.
/// JACK uses this for the client name of the client that connects when you
/// open the stream.
/// WASAPI uses this for the session display name.
/// Must not contain a colon (":").
const char *name;
/// Optional: Hint that this output stream is nonterminal. This is used by
/// JACK and it means that the output stream data originates from an input
/// stream. Defaults to `false`.
bool non_terminal_hint;
/// computed automatically when you call ::soundio_outstream_open
int bytes_per_frame;
/// computed automatically when you call ::soundio_outstream_open
int bytes_per_sample;
/// If setting the channel layout fails for some reason, this field is set
/// to an error code. Possible error codes are:
/// * #SoundIoErrorIncompatibleDevice
int layout_error;
};
/// The size of this struct is not part of the API or ABI.
struct SoundIoInStream {
/// Populated automatically when you call ::soundio_outstream_create.
struct SoundIoDevice *device;
/// Defaults to #SoundIoFormatFloat32NE, followed by the first one
/// supported.
enum SoundIoFormat format;
/// Sample rate is the number of frames per second.
/// Defaults to max(sample_rate_min, min(sample_rate_max, 48000))
int sample_rate;
/// Defaults to Stereo, if available, followed by the first layout
/// supported.
struct SoundIoChannelLayout layout;
/// Ignoring hardware latency, this is the number of seconds it takes for a
/// captured sample to become available for reading.
/// After you call ::soundio_instream_open, this value is replaced with the
/// actual software latency, as near to this value as possible.
/// A higher value means less CPU usage. Defaults to a large value,
/// potentially upwards of 2 seconds.
/// If the device has unknown software latency min and max values, you may
/// still set this, but you might not get the value you requested.
/// For PulseAudio, if you set this value to non-default, it sets
/// `PA_STREAM_ADJUST_LATENCY` and is the value used for `fragsize`.
/// For JACK, this value is always equal to
/// SoundIoDevice::software_latency_current
double software_latency;
/// Defaults to NULL. Put whatever you want here.
void *userdata;
/// In this function call ::soundio_instream_begin_read and
/// ::soundio_instream_end_read as many times as necessary to read at
/// minimum `frame_count_min` frames and at maximum `frame_count_max`
/// frames. If you return from read_callback without having read
/// `frame_count_min`, the frames will be dropped. `frame_count_max` is how
/// many frames are available to read.
///
/// The code in the supplied function must be suitable for real-time
/// execution. That means that it cannot call functions that might block
/// for a long time. This includes all I/O functions (disk, TTY, network),
/// malloc, free, printf, pthread_mutex_lock, sleep, wait, poll, select,
/// pthread_join, pthread_cond_wait, etc.
void (*read_callback)(struct SoundIoInStream *, int frame_count_min, int frame_count_max);
/// This optional callback happens when the sound device buffer is full,
/// yet there is more captured audio to put in it.
/// This is never fired for PulseAudio.
/// This is called from the SoundIoInStream::read_callback thread context.
void (*overflow_callback)(struct SoundIoInStream *);
/// Optional callback. `err` is always SoundIoErrorStreaming.
/// SoundIoErrorStreaming is an unrecoverable error. The stream is in an
/// invalid state and must be destroyed.
/// If you do not supply `error_callback`, the default callback will print
/// a message to stderr and then abort().
/// This is called from the SoundIoInStream::read_callback thread context.
void (*error_callback)(struct SoundIoInStream *, int err);
/// Optional: Name of the stream. Defaults to "SoundIoInStream";
/// PulseAudio uses this for the stream name.
/// JACK uses this for the client name of the client that connects when you
/// open the stream.
/// WASAPI uses this for the session display name.
/// Must not contain a colon (":").
const char *name;
/// Optional: Hint that this input stream is nonterminal. This is used by
/// JACK and it means that the data received by the stream will be
/// passed on or made available to another stream. Defaults to `false`.
bool non_terminal_hint;
/// computed automatically when you call ::soundio_instream_open
int bytes_per_frame;
/// computed automatically when you call ::soundio_instream_open
int bytes_per_sample;
/// If setting the channel layout fails for some reason, this field is set
/// to an error code. Possible error codes are: #SoundIoErrorIncompatibleDevice
int layout_error;
};
/// See also ::soundio_version_major, ::soundio_version_minor, ::soundio_version_patch
SOUNDIO_EXPORT const char *soundio_version_string(void);
/// See also ::soundio_version_string, ::soundio_version_minor, ::soundio_version_patch
SOUNDIO_EXPORT int soundio_version_major(void);
/// See also ::soundio_version_major, ::soundio_version_string, ::soundio_version_patch
SOUNDIO_EXPORT int soundio_version_minor(void);
/// See also ::soundio_version_major, ::soundio_version_minor, ::soundio_version_string
SOUNDIO_EXPORT int soundio_version_patch(void);
/// Create a SoundIo context. You may create multiple instances of this to
/// connect to multiple backends. Sets all fields to defaults.
/// Returns `NULL` if and only if memory could not be allocated.
/// See also ::soundio_destroy
SOUNDIO_EXPORT struct SoundIo *soundio_create(void);
SOUNDIO_EXPORT void soundio_destroy(struct SoundIo *soundio);
/// Tries ::soundio_connect_backend on all available backends in order.
/// Possible errors:
/// * #SoundIoErrorInvalid - already connected
/// * #SoundIoErrorNoMem
/// * #SoundIoErrorSystemResources
/// * #SoundIoErrorNoSuchClient - when JACK returns `JackNoSuchClient`
/// See also ::soundio_disconnect
SOUNDIO_EXPORT int soundio_connect(struct SoundIo *soundio);
/// Instead of calling ::soundio_connect you may call this function to try a
/// specific backend.
/// Possible errors:
/// * #SoundIoErrorInvalid - already connected or invalid backend parameter
/// * #SoundIoErrorNoMem
/// * #SoundIoErrorBackendUnavailable - backend was not compiled in
/// * #SoundIoErrorSystemResources
/// * #SoundIoErrorNoSuchClient - when JACK returns `JackNoSuchClient`
/// * #SoundIoErrorInitAudioBackend - requested `backend` is not active
/// * #SoundIoErrorBackendDisconnected - backend disconnected while connecting
/// See also ::soundio_disconnect
SOUNDIO_EXPORT int soundio_connect_backend(struct SoundIo *soundio, enum SoundIoBackend backend);
SOUNDIO_EXPORT void soundio_disconnect(struct SoundIo *soundio);
/// Get a string representation of a #SoundIoError
SOUNDIO_EXPORT const char *soundio_strerror(int error);
/// Get a string representation of a #SoundIoBackend
SOUNDIO_EXPORT const char *soundio_backend_name(enum SoundIoBackend backend);
/// Returns the number of available backends.
SOUNDIO_EXPORT int soundio_backend_count(struct SoundIo *soundio);
/// get the available backend at the specified index
/// (0 <= index < ::soundio_backend_count)
SOUNDIO_EXPORT enum SoundIoBackend soundio_get_backend(struct SoundIo *soundio, int index);
/// Returns whether libsoundio was compiled with backend.
SOUNDIO_EXPORT bool soundio_have_backend(enum SoundIoBackend backend);
/// Atomically update information for all connected devices. Note that calling
/// this function merely flips a pointer; the actual work of collecting device
/// information is done elsewhere. It is performant to call this function many
/// times per second.
///
/// When you call this, the following callbacks might be called:
/// * SoundIo::on_devices_change
/// * SoundIo::on_backend_disconnect
/// This is the only time those callbacks can be called.
///
/// This must be called from the same thread as the thread in which you call
/// these functions:
/// * ::soundio_input_device_count
/// * ::soundio_output_device_count
/// * ::soundio_get_input_device
/// * ::soundio_get_output_device
/// * ::soundio_default_input_device_index
/// * ::soundio_default_output_device_index
///
/// Note that if you do not care about learning about updated devices, you
/// might call this function only once ever and never call
/// ::soundio_wait_events.
SOUNDIO_EXPORT void soundio_flush_events(struct SoundIo *soundio);
/// This function calls ::soundio_flush_events then blocks until another event
/// is ready or you call ::soundio_wakeup. Be ready for spurious wakeups.
SOUNDIO_EXPORT void soundio_wait_events(struct SoundIo *soundio);
/// Makes ::soundio_wait_events stop blocking.
SOUNDIO_EXPORT void soundio_wakeup(struct SoundIo *soundio);
/// If necessary you can manually trigger a device rescan. Normally you will
/// not ever have to call this function, as libsoundio listens to system events
/// for device changes and responds to them by rescanning devices and preparing
/// the new device information for you to be atomically replaced when you call
/// ::soundio_flush_events. However you might run into cases where you want to
/// force trigger a device rescan, for example if an ALSA device has a
/// SoundIoDevice::probe_error.
///
/// After you call this you still have to use ::soundio_flush_events or
/// ::soundio_wait_events and then wait for the
/// SoundIo::on_devices_change callback.
///
/// This can be called from any thread context except for
/// SoundIoOutStream::write_callback and SoundIoInStream::read_callback
SOUNDIO_EXPORT void soundio_force_device_scan(struct SoundIo *soundio);
// Channel Layouts
/// Returns whether the channel count field and each channel id matches in
/// the supplied channel layouts.
SOUNDIO_EXPORT bool soundio_channel_layout_equal(
const struct SoundIoChannelLayout *a,
const struct SoundIoChannelLayout *b);
SOUNDIO_EXPORT const char *soundio_get_channel_name(enum SoundIoChannelId id);
/// Given UTF-8 encoded text which is the name of a channel such as
/// "Front Left", "FL", or "front-left", return the corresponding
/// SoundIoChannelId. Returns SoundIoChannelIdInvalid for no match.
SOUNDIO_EXPORT enum SoundIoChannelId soundio_parse_channel_id(const char *str, int str_len);
/// Returns the number of builtin channel layouts.
SOUNDIO_EXPORT int soundio_channel_layout_builtin_count(void);
/// Returns a builtin channel layout. 0 <= `index` < ::soundio_channel_layout_builtin_count
///
/// Although `index` is of type `int`, it should be a valid
/// #SoundIoChannelLayoutId enum value.
SOUNDIO_EXPORT const struct SoundIoChannelLayout *soundio_channel_layout_get_builtin(int index);
/// Get the default builtin channel layout for the given number of channels.
SOUNDIO_EXPORT const struct SoundIoChannelLayout *soundio_channel_layout_get_default(int channel_count);
/// Return the index of `channel` in `layout`, or `-1` if not found.
SOUNDIO_EXPORT int soundio_channel_layout_find_channel(
const struct SoundIoChannelLayout *layout, enum SoundIoChannelId channel);
/// Populates the name field of layout if it matches a builtin one.
/// returns whether it found a match
SOUNDIO_EXPORT bool soundio_channel_layout_detect_builtin(struct SoundIoChannelLayout *layout);
/// Iterates over preferred_layouts. Returns the first channel layout in
/// preferred_layouts which matches one of the channel layouts in
/// available_layouts. Returns NULL if none matches.
SOUNDIO_EXPORT const struct SoundIoChannelLayout *soundio_best_matching_channel_layout(
const struct SoundIoChannelLayout *preferred_layouts, int preferred_layout_count,
const struct SoundIoChannelLayout *available_layouts, int available_layout_count);
/// Sorts by channel count, descending.
SOUNDIO_EXPORT void soundio_sort_channel_layouts(struct SoundIoChannelLayout *layouts, int layout_count);
// Sample Formats
/// Returns -1 on invalid format.
SOUNDIO_EXPORT int soundio_get_bytes_per_sample(enum SoundIoFormat format);
/// A frame is one sample per channel.
static inline int soundio_get_bytes_per_frame(enum SoundIoFormat format, int channel_count) {
return soundio_get_bytes_per_sample(format) * channel_count;
}
/// Sample rate is the number of frames per second.
static inline int soundio_get_bytes_per_second(enum SoundIoFormat format,
int channel_count, int sample_rate)
{
return soundio_get_bytes_per_frame(format, channel_count) * sample_rate;
}
/// Returns string representation of `format`.
SOUNDIO_EXPORT const char * soundio_format_string(enum SoundIoFormat format);
// Devices
/// When you call ::soundio_flush_events, a snapshot of all device state is
/// saved and these functions merely access the snapshot data. When you want
/// to check for new devices, call ::soundio_flush_events. Or you can call
/// ::soundio_wait_events to block until devices change. If an error occurs
/// scanning devices in a background thread, SoundIo::on_backend_disconnect is called
/// with the error code.
/// Get the number of input devices.
/// Returns -1 if you never called ::soundio_flush_events.
SOUNDIO_EXPORT int soundio_input_device_count(struct SoundIo *soundio);
/// Get the number of output devices.
/// Returns -1 if you never called ::soundio_flush_events.
SOUNDIO_EXPORT int soundio_output_device_count(struct SoundIo *soundio);
/// Always returns a device. Call ::soundio_device_unref when done.
/// `index` must be 0 <= index < ::soundio_input_device_count
/// Returns NULL if you never called ::soundio_flush_events or if you provide
/// invalid parameter values.
SOUNDIO_EXPORT struct SoundIoDevice *soundio_get_input_device(struct SoundIo *soundio, int index);
/// Always returns a device. Call ::soundio_device_unref when done.
/// `index` must be 0 <= index < ::soundio_output_device_count
/// Returns NULL if you never called ::soundio_flush_events or if you provide
/// invalid parameter values.
SOUNDIO_EXPORT struct SoundIoDevice *soundio_get_output_device(struct SoundIo *soundio, int index);
/// returns the index of the default input device
/// returns -1 if there are no devices or if you never called
/// ::soundio_flush_events.
SOUNDIO_EXPORT int soundio_default_input_device_index(struct SoundIo *soundio);
/// returns the index of the default output device
/// returns -1 if there are no devices or if you never called
/// ::soundio_flush_events.
SOUNDIO_EXPORT int soundio_default_output_device_index(struct SoundIo *soundio);
/// Add 1 to the reference count of `device`.
SOUNDIO_EXPORT void soundio_device_ref(struct SoundIoDevice *device);
/// Remove 1 to the reference count of `device`. Clean up if it was the last
/// reference.
SOUNDIO_EXPORT void soundio_device_unref(struct SoundIoDevice *device);
/// Return `true` if and only if the devices have the same SoundIoDevice::id,
/// SoundIoDevice::is_raw, and SoundIoDevice::aim are the same.
SOUNDIO_EXPORT bool soundio_device_equal(
const struct SoundIoDevice *a,
const struct SoundIoDevice *b);
/// Sorts channel layouts by channel count, descending.
SOUNDIO_EXPORT void soundio_device_sort_channel_layouts(struct SoundIoDevice *device);
/// Convenience function. Returns whether `format` is included in the device's
/// supported formats.
SOUNDIO_EXPORT bool soundio_device_supports_format(struct SoundIoDevice *device,
enum SoundIoFormat format);
/// Convenience function. Returns whether `layout` is included in the device's
/// supported channel layouts.
SOUNDIO_EXPORT bool soundio_device_supports_layout(struct SoundIoDevice *device,
const struct SoundIoChannelLayout *layout);
/// Convenience function. Returns whether `sample_rate` is included in the
/// device's supported sample rates.
SOUNDIO_EXPORT bool soundio_device_supports_sample_rate(struct SoundIoDevice *device,
int sample_rate);
/// Convenience function. Returns the available sample rate nearest to
/// `sample_rate`, rounding up.
SOUNDIO_EXPORT int soundio_device_nearest_sample_rate(struct SoundIoDevice *device,
int sample_rate);
// Output Streams
/// Allocates memory and sets defaults. Next you should fill out the struct fields
/// and then call ::soundio_outstream_open. Sets all fields to defaults.
/// Returns `NULL` if and only if memory could not be allocated.
/// See also ::soundio_outstream_destroy
SOUNDIO_EXPORT struct SoundIoOutStream *soundio_outstream_create(struct SoundIoDevice *device);
/// You may not call this function from the SoundIoOutStream::write_callback thread context.
SOUNDIO_EXPORT void soundio_outstream_destroy(struct SoundIoOutStream *outstream);
/// After you call this function, SoundIoOutStream::software_latency is set to
/// the correct value.
///
/// The next thing to do is call ::soundio_outstream_start.
/// If this function returns an error, the outstream is in an invalid state and
/// you must call ::soundio_outstream_destroy on it.
///
/// Possible errors:
/// * #SoundIoErrorInvalid
/// * SoundIoDevice::aim is not #SoundIoDeviceAimOutput
/// * SoundIoOutStream::format is not valid
/// * SoundIoOutStream::channel_count is greater than #SOUNDIO_MAX_CHANNELS
/// * #SoundIoErrorNoMem
/// * #SoundIoErrorOpeningDevice
/// * #SoundIoErrorBackendDisconnected
/// * #SoundIoErrorSystemResources
/// * #SoundIoErrorNoSuchClient - when JACK returns `JackNoSuchClient`
/// * #SoundIoErrorIncompatibleBackend - SoundIoOutStream::channel_count is
/// greater than the number of channels the backend can handle.
/// * #SoundIoErrorIncompatibleDevice - stream parameters requested are not
/// compatible with the chosen device.
SOUNDIO_EXPORT int soundio_outstream_open(struct SoundIoOutStream *outstream);
/// After you call this function, SoundIoOutStream::write_callback will be called.
///
/// This function might directly call SoundIoOutStream::write_callback.
///
/// Possible errors:
/// * #SoundIoErrorStreaming
/// * #SoundIoErrorNoMem
/// * #SoundIoErrorSystemResources
/// * #SoundIoErrorBackendDisconnected
SOUNDIO_EXPORT int soundio_outstream_start(struct SoundIoOutStream *outstream);
/// Call this function when you are ready to begin writing to the device buffer.
/// * `outstream` - (in) The output stream you want to write to.
/// * `areas` - (out) The memory addresses you can write data to, one per
/// channel. It is OK to modify the pointers if that helps you iterate.
/// * `frame_count` - (in/out) Provide the number of frames you want to write.
/// Returned will be the number of frames you can actually write, which is
/// also the number of frames that will be written when you call
/// ::soundio_outstream_end_write. The value returned will always be less
/// than or equal to the value provided.
/// It is your responsibility to call this function exactly as many times as
/// necessary to meet the `frame_count_min` and `frame_count_max` criteria from
/// SoundIoOutStream::write_callback.
/// You must call this function only from the SoundIoOutStream::write_callback thread context.
/// After calling this function, write data to `areas` and then call
/// ::soundio_outstream_end_write.
/// If this function returns an error, do not call ::soundio_outstream_end_write.
///
/// Possible errors:
/// * #SoundIoErrorInvalid
/// * `*frame_count` <= 0
/// * `*frame_count` < `frame_count_min` or `*frame_count` > `frame_count_max`
/// * function called too many times without respecting `frame_count_max`
/// * #SoundIoErrorStreaming
/// * #SoundIoErrorUnderflow - an underflow caused this call to fail. You might
/// also get a SoundIoOutStream::underflow_callback, and you might not get
/// this error code when an underflow occurs. Unlike #SoundIoErrorStreaming,
/// the outstream is still in a valid state and streaming can continue.
/// * #SoundIoErrorIncompatibleDevice - in rare cases it might just now
/// be discovered that the device uses non-byte-aligned access, in which
/// case this error code is returned.
SOUNDIO_EXPORT int soundio_outstream_begin_write(struct SoundIoOutStream *outstream,
struct SoundIoChannelArea **areas, int *frame_count);
/// Commits the write that you began with ::soundio_outstream_begin_write.
/// You must call this function only from the SoundIoOutStream::write_callback thread context.
///
/// Possible errors:
/// * #SoundIoErrorStreaming
/// * #SoundIoErrorUnderflow - an underflow caused this call to fail. You might
/// also get a SoundIoOutStream::underflow_callback, and you might not get
/// this error code when an underflow occurs. Unlike #SoundIoErrorStreaming,
/// the outstream is still in a valid state and streaming can continue.
SOUNDIO_EXPORT int soundio_outstream_end_write(struct SoundIoOutStream *outstream);
/// Clears the output stream buffer.
/// This function can be called from any thread.
/// This function can be called regardless of whether the outstream is paused
/// or not.
/// Some backends do not support clearing the buffer. On these backends this
/// function will return SoundIoErrorIncompatibleBackend.
/// Some devices do not support clearing the buffer. On these devices this
/// function might return SoundIoErrorIncompatibleDevice.
/// Possible errors:
///
/// * #SoundIoErrorStreaming
/// * #SoundIoErrorIncompatibleBackend
/// * #SoundIoErrorIncompatibleDevice
SOUNDIO_EXPORT int soundio_outstream_clear_buffer(struct SoundIoOutStream *outstream);
/// If the underlying backend and device support pausing, this pauses the
/// stream. SoundIoOutStream::write_callback may be called a few more times if
/// the buffer is not full.
/// Pausing might put the hardware into a low power state which is ideal if your
/// software is silent for some time.
/// This function may be called from any thread context, including
/// SoundIoOutStream::write_callback.
/// Pausing when already paused or unpausing when already unpaused has no
/// effect and returns #SoundIoErrorNone.
///
/// Possible errors:
/// * #SoundIoErrorBackendDisconnected
/// * #SoundIoErrorStreaming
/// * #SoundIoErrorIncompatibleDevice - device does not support
/// pausing/unpausing. This error code might not be returned even if the
/// device does not support pausing/unpausing.
/// * #SoundIoErrorIncompatibleBackend - backend does not support
/// pausing/unpausing.
/// * #SoundIoErrorInvalid - outstream not opened and started
SOUNDIO_EXPORT int soundio_outstream_pause(struct SoundIoOutStream *outstream, bool pause);
/// Obtain the total number of seconds that the next frame written after the
/// last frame written with ::soundio_outstream_end_write will take to become
/// audible. This includes both software and hardware latency. In other words,
/// if you call this function directly after calling ::soundio_outstream_end_write,
/// this gives you the number of seconds that the next frame written will take
/// to become audible.
///
/// This function must be called only from within SoundIoOutStream::write_callback.
///
/// Possible errors:
/// * #SoundIoErrorStreaming
SOUNDIO_EXPORT int soundio_outstream_get_latency(struct SoundIoOutStream *outstream,
double *out_latency);
SOUNDIO_EXPORT int soundio_outstream_set_volume(struct SoundIoOutStream *outstream,
double volume);
// Input Streams
/// Allocates memory and sets defaults. Next you should fill out the struct fields
/// and then call ::soundio_instream_open. Sets all fields to defaults.
/// Returns `NULL` if and only if memory could not be allocated.
/// See also ::soundio_instream_destroy
SOUNDIO_EXPORT struct SoundIoInStream *soundio_instream_create(struct SoundIoDevice *device);
/// You may not call this function from SoundIoInStream::read_callback.
SOUNDIO_EXPORT void soundio_instream_destroy(struct SoundIoInStream *instream);
/// After you call this function, SoundIoInStream::software_latency is set to the correct
/// value.
/// The next thing to do is call ::soundio_instream_start.
/// If this function returns an error, the instream is in an invalid state and
/// you must call ::soundio_instream_destroy on it.
///
/// Possible errors:
/// * #SoundIoErrorInvalid
/// * device aim is not #SoundIoDeviceAimInput
/// * format is not valid
/// * requested layout channel count > #SOUNDIO_MAX_CHANNELS
/// * #SoundIoErrorOpeningDevice
/// * #SoundIoErrorNoMem
/// * #SoundIoErrorBackendDisconnected
/// * #SoundIoErrorSystemResources
/// * #SoundIoErrorNoSuchClient
/// * #SoundIoErrorIncompatibleBackend
/// * #SoundIoErrorIncompatibleDevice
SOUNDIO_EXPORT int soundio_instream_open(struct SoundIoInStream *instream);
/// After you call this function, SoundIoInStream::read_callback will be called.
///
/// Possible errors:
/// * #SoundIoErrorBackendDisconnected
/// * #SoundIoErrorStreaming
/// * #SoundIoErrorOpeningDevice
/// * #SoundIoErrorSystemResources
SOUNDIO_EXPORT int soundio_instream_start(struct SoundIoInStream *instream);
/// Call this function when you are ready to begin reading from the device
/// buffer.
/// * `instream` - (in) The input stream you want to read from.
/// * `areas` - (out) The memory addresses you can read data from. It is OK
/// to modify the pointers if that helps you iterate. There might be a "hole"
/// in the buffer. To indicate this, `areas` will be `NULL` and `frame_count`
/// tells how big the hole is in frames.
/// * `frame_count` - (in/out) - Provide the number of frames you want to read;
/// returns the number of frames you can actually read. The returned value
/// will always be less than or equal to the provided value. If the provided
/// value is less than `frame_count_min` from SoundIoInStream::read_callback this function
/// returns with #SoundIoErrorInvalid.
/// It is your responsibility to call this function no more and no fewer than the
/// correct number of times according to the `frame_count_min` and
/// `frame_count_max` criteria from SoundIoInStream::read_callback.
/// You must call this function only from the SoundIoInStream::read_callback thread context.
/// After calling this function, read data from `areas` and then use
/// ::soundio_instream_end_read` to actually remove the data from the buffer
/// and move the read index forward. ::soundio_instream_end_read should not be
/// called if the buffer is empty (`frame_count` == 0), but it should be called
/// if there is a hole.
///
/// Possible errors:
/// * #SoundIoErrorInvalid
/// * `*frame_count` < `frame_count_min` or `*frame_count` > `frame_count_max`
/// * #SoundIoErrorStreaming
/// * #SoundIoErrorIncompatibleDevice - in rare cases it might just now
/// be discovered that the device uses non-byte-aligned access, in which
/// case this error code is returned.
SOUNDIO_EXPORT int soundio_instream_begin_read(struct SoundIoInStream *instream,
struct SoundIoChannelArea **areas, int *frame_count);
/// This will drop all of the frames from when you called
/// ::soundio_instream_begin_read.
/// You must call this function only from the SoundIoInStream::read_callback thread context.
/// You must call this function only after a successful call to
/// ::soundio_instream_begin_read.
///
/// Possible errors:
/// * #SoundIoErrorStreaming
SOUNDIO_EXPORT int soundio_instream_end_read(struct SoundIoInStream *instream);
/// If the underyling device supports pausing, this pauses the stream and
/// prevents SoundIoInStream::read_callback from being called. Otherwise this returns
/// #SoundIoErrorIncompatibleDevice.
/// This function may be called from any thread.
/// Pausing when already paused or unpausing when already unpaused has no
/// effect and always returns #SoundIoErrorNone.
///
/// Possible errors:
/// * #SoundIoErrorBackendDisconnected
/// * #SoundIoErrorStreaming
/// * #SoundIoErrorIncompatibleDevice - device does not support pausing/unpausing
SOUNDIO_EXPORT int soundio_instream_pause(struct SoundIoInStream *instream, bool pause);
/// Obtain the number of seconds that the next frame of sound being
/// captured will take to arrive in the buffer, plus the amount of time that is
/// represented in the buffer. This includes both software and hardware latency.
///
/// This function must be called only from within SoundIoInStream::read_callback.
///
/// Possible errors:
/// * #SoundIoErrorStreaming
SOUNDIO_EXPORT int soundio_instream_get_latency(struct SoundIoInStream *instream,
double *out_latency);
struct SoundIoRingBuffer;
/// A ring buffer is a single-reader single-writer lock-free fixed-size queue.
/// libsoundio ring buffers use memory mapping techniques to enable a
/// contiguous buffer when reading or writing across the boundary of the ring
/// buffer's capacity.
/// `requested_capacity` in bytes.
/// Returns `NULL` if and only if memory could not be allocated.
/// Use ::soundio_ring_buffer_capacity to get the actual capacity, which might
/// be greater for alignment purposes.
/// See also ::soundio_ring_buffer_destroy
SOUNDIO_EXPORT struct SoundIoRingBuffer *soundio_ring_buffer_create(struct SoundIo *soundio, int requested_capacity);
SOUNDIO_EXPORT void soundio_ring_buffer_destroy(struct SoundIoRingBuffer *ring_buffer);
/// When you create a ring buffer, capacity might be more than the requested
/// capacity for alignment purposes. This function returns the actual capacity.
SOUNDIO_EXPORT int soundio_ring_buffer_capacity(struct SoundIoRingBuffer *ring_buffer);
/// Do not write more than capacity.
SOUNDIO_EXPORT char *soundio_ring_buffer_write_ptr(struct SoundIoRingBuffer *ring_buffer);
/// `count` in bytes.
SOUNDIO_EXPORT void soundio_ring_buffer_advance_write_ptr(struct SoundIoRingBuffer *ring_buffer, int count);
/// Do not read more than capacity.
SOUNDIO_EXPORT char *soundio_ring_buffer_read_ptr(struct SoundIoRingBuffer *ring_buffer);
/// `count` in bytes.
SOUNDIO_EXPORT void soundio_ring_buffer_advance_read_ptr(struct SoundIoRingBuffer *ring_buffer, int count);
/// Returns how many bytes of the buffer is used, ready for reading.
SOUNDIO_EXPORT int soundio_ring_buffer_fill_count(struct SoundIoRingBuffer *ring_buffer);
/// Returns how many bytes of the buffer is free, ready for writing.
SOUNDIO_EXPORT int soundio_ring_buffer_free_count(struct SoundIoRingBuffer *ring_buffer);
/// Must be called by the writer.
SOUNDIO_EXPORT void soundio_ring_buffer_clear(struct SoundIoRingBuffer *ring_buffer);
#endif