SDL_audio.h File Reference
`#include "SDL_stdinc.h"`
`#include "SDL_error.h"`
`#include "SDL_endian.h"`
`#include "SDL_mutex.h"`
`#include "SDL_thread.h"`
`#include "SDL_rwops.h"`
`#include "begin_code.h"`
`#include "close_code.h"`
Include dependency graph for SDL_audio.h:
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Go to the source code of this file.

## Data Structures

struct | SDL_AudioSpec
struct | SDL_AudioCVT

## Macros

#define | SDL_AUDIOCVT_PACKED
#define | SDL_LoadWAV(file, spec, audio_buf, audio_len) SDL_LoadWAV_RW(SDL_RWFromFile(file, "rb"),1, spec,audio_buf,audio_len)
#define | SDL_MIX_MAXVOLUME 128
Audio flags
#define | SDL_AUDIO_MASK_BITSIZE (0xFF)
#define | SDL_AUDIO_MASK_DATATYPE (1<<8)
#define | SDL_AUDIO_MASK_ENDIAN (1<<12)
#define | SDL_AUDIO_MASK_SIGNED (1<<15)
#define | SDL_AUDIO_BITSIZE(x) (x & SDL_AUDIO_MASK_BITSIZE)
#define | SDL_AUDIO_ISFLOAT(x) (x & SDL_AUDIO_MASK_DATATYPE)
#define | SDL_AUDIO_ISBIGENDIAN(x) (x & SDL_AUDIO_MASK_ENDIAN)
#define | SDL_AUDIO_ISSIGNED(x) (x & SDL_AUDIO_MASK_SIGNED)
#define | SDL_AUDIO_ISINT(x) (!SDL_AUDIO_ISFLOAT(x))
#define | SDL_AUDIO_ISLITTLEENDIAN(x) (!SDL_AUDIO_ISBIGENDIAN(x))
#define | SDL_AUDIO_ISUNSIGNED(x) (!SDL_AUDIO_ISSIGNED(x))
Audio format flags
Defaults to LSB byte order.
#define | AUDIO_U8 0x0008
#define | AUDIO_S8 0x8008
#define | AUDIO_U16LSB 0x0010
#define | AUDIO_S16LSB 0x8010
#define | AUDIO_U16MSB 0x1010
#define | AUDIO_S16MSB 0x9010
#define | AUDIO_U16 AUDIO_U16LSB
#define | AUDIO_S16 AUDIO_S16LSB
int32 support
#define | AUDIO_S32LSB 0x8020
#define | AUDIO_S32MSB 0x9020
#define | AUDIO_S32 AUDIO_S32LSB
float32 support
#define | AUDIO_F32LSB 0x8120
#define | AUDIO_F32MSB 0x9120
#define | AUDIO_F32 AUDIO_F32LSB
Native audio byte ordering
#define | AUDIO_U16SYS AUDIO_U16LSB
#define | AUDIO_S16SYS AUDIO_S16LSB
#define | AUDIO_S32SYS AUDIO_S32LSB
#define | AUDIO_F32SYS AUDIO_F32LSB
Allow change flags
Which audio format changes are allowed when opening a device.
#define | SDL_AUDIO_ALLOW_FREQUENCY_CHANGE 0x00000001
#define | SDL_AUDIO_ALLOW_FORMAT_CHANGE 0x00000002
#define | SDL_AUDIO_ALLOW_CHANNELS_CHANGE 0x00000004
#define | SDL_AUDIO_ALLOW_ANY_CHANGE (SDL_AUDIO_ALLOW_FREQUENCY_CHANGE|SDL_AUDIO_ALLOW_FORMAT_CHANGE|SDL_AUDIO_ALLOW_CHANNELS_CHANGE)

## Typedefs

typedef Uint16 | SDL_AudioFormat
| Audio format flags. More...
typedef void(* | SDL_AudioCallback) (void *userdata, Uint8 *stream, int len)
typedef void(* | SDL_AudioFilter) (struct SDL_AudioCVT *cvt, SDL_AudioFormat format)
typedef Uint32 | SDL_AudioDeviceID

## Functions

const char * | SDL_GetCurrentAudioDriver (void)
int | SDL_OpenAudio (SDL_AudioSpec *desired, SDL_AudioSpec *obtained)
int | SDL_GetNumAudioDevices (int iscapture)
const char * | SDL_GetAudioDeviceName (int index, int iscapture)
SDL_AudioDeviceID | SDL_OpenAudioDevice (const char *device, int iscapture, const SDL_AudioSpec *desired, SDL_AudioSpec *obtained, int allowed_changes)
SDL_AudioSpec * | SDL_LoadWAV_RW (SDL_RWops *src, int freesrc, SDL_AudioSpec *spec, Uint8 **audio_buf, Uint32 *audio_len)
void | SDL_FreeWAV (Uint8 *audio_buf)
int | SDL_BuildAudioCVT (SDL_AudioCVT *cvt, SDL_AudioFormat src_format, Uint8 src_channels, int src_rate, SDL_AudioFormat dst_format, Uint8 dst_channels, int dst_rate)
int | SDL_ConvertAudio (SDL_AudioCVT *cvt)
void | SDL_MixAudio (Uint8 *dst, const Uint8 *src, Uint32 len, int volume)
void | SDL_MixAudioFormat (Uint8 *dst, const Uint8 *src, SDL_AudioFormat format, Uint32 len, int volume)
int | SDL_QueueAudio (SDL_AudioDeviceID dev, const void *data, Uint32 len)
Uint32 | SDL_GetQueuedAudioSize (SDL_AudioDeviceID dev)
void | SDL_ClearQueuedAudio (SDL_AudioDeviceID dev)
void | SDL_CloseAudio (void)
void | SDL_CloseAudioDevice (SDL_AudioDeviceID dev)
Driver discovery functions
These functions return the list of built in audio drivers, in the order that they are normally initialized by default.
int | SDL_GetNumAudioDrivers (void)
const char * | SDL_GetAudioDriver (int index)
Initialization and cleanup
These functions are used internally, and should not be used unless you have a specific need to specify the audio driver you want to use. You should normally use SDL_Init() or SDL_InitSubSystem().
int | SDL_AudioInit (const char *driver_name)
void | SDL_AudioQuit (void)
Pause audio functions
These functions pause and unpause the audio callback processing. They should be called with a parameter of 0 after opening the audio device to start playing sound. This is so you can safely initialize data for your callback function after opening the audio device. Silence will be written to the audio device during the pause.
void | SDL_PauseAudio (int pause_on)
void | SDL_PauseAudioDevice (SDL_AudioDeviceID dev, int pause_on)
Audio lock functions
The lock manipulated by these functions protects the callback function. During a SDL_LockAudio()/SDL_UnlockAudio() pair, you can be guaranteed that the callback function is not running. Do not call these from the callback function or you will cause deadlock.
void | SDL_LockAudio (void)
void | SDL_LockAudioDevice (SDL_AudioDeviceID dev)
void | SDL_UnlockAudio (void)
void | SDL_UnlockAudioDevice (SDL_AudioDeviceID dev)

## Audio state

Get the current audio state.
enum | SDL_AudioStatus { SDL_AUDIO_STOPPED = 0, SDL_AUDIO_PLAYING, SDL_AUDIO_PAUSED }
SDL_AudioStatus | SDL_GetAudioStatus (void)
SDL_AudioStatus | SDL_GetAudioDeviceStatus (SDL_AudioDeviceID dev)

## Detailed Description

Access to the raw audio mixing buffer for the SDL library.

Definition in file SDL_audio.h.

## Macro Definition Documentation

#define AUDIO_F32 AUDIO_F32LSB

Definition at line 114 of file SDL_audio.h.

Referenced by SDL_ConvertMono(), SDL_ConvertSurround(), SDL_ConvertSurround_4(), and SDL_LoadWAV_RW().

#define AUDIO_F32LSB 0x8120

32-bit floating point samples

Definition at line 112 of file SDL_audio.h.

Referenced by SDL_Convert_F32MSB_to_F32LSB(), SDL_Convert_S16LSB_to_F32LSB(), SDL_Convert_S16MSB_to_F32LSB(), SDL_Convert_S32LSB_to_F32LSB(), SDL_Convert_S32MSB_to_F32LSB(), SDL_Convert_S8_to_F32LSB(), SDL_Convert_U16LSB_to_F32LSB(), SDL_Convert_U16MSB_to_F32LSB(), SDL_Convert_U8_to_F32LSB(), and SDL_MixAudioFormat().

#define AUDIO_F32MSB 0x9120

As above, but big-endian byte order

Definition at line 113 of file SDL_audio.h.

Referenced by SDL_Convert_F32LSB_to_F32MSB(), SDL_Convert_S16LSB_to_F32MSB(), SDL_Convert_S16MSB_to_F32MSB(), SDL_Convert_S32LSB_to_F32MSB(), SDL_Convert_S32MSB_to_F32MSB(), SDL_Convert_S8_to_F32MSB(), SDL_Convert_U16LSB_to_F32MSB(), SDL_Convert_U16MSB_to_F32MSB(), SDL_Convert_U8_to_F32MSB(), and SDL_MixAudioFormat().

#define AUDIO_F32SYS AUDIO_F32LSB

Definition at line 125 of file SDL_audio.h.

Referenced by audio_initOpenCloseQuitAudio(), and audio_pauseUnpauseAudio().

#define AUDIO_S16 AUDIO_S16LSB

Definition at line 96 of file SDL_audio.h.

Referenced by prepare_audiospec(), SDL_ConvertMono(), SDL_ConvertSurround(), SDL_ConvertSurround_4(), SDL_LoadWAV_RW(), SDLTest_CommonArg(), and SDLTest_CommonCreateState().

#define AUDIO_S16LSB 0x8010

Signed 16-bit samples

Definition at line 92 of file SDL_audio.h.

Referenced by audio_buildAudioCVT(), audio_buildAudioCVTNegative(), SDL_Convert_F32LSB_to_S16LSB(), SDL_Convert_F32MSB_to_S16LSB(), SDL_Convert_S16MSB_to_S16LSB(), SDL_Convert_S32LSB_to_S16LSB(), SDL_Convert_S32MSB_to_S16LSB(), SDL_Convert_S8_to_S16LSB(), SDL_Convert_U16LSB_to_S16LSB(), SDL_Convert_U16MSB_to_S16LSB(), SDL_Convert_U8_to_S16LSB(), SDL_MixAudioFormat(), and SDLTest_CommonArg().

#define AUDIO_S16MSB 0x9010

As above, but big-endian byte order

Definition at line 94 of file SDL_audio.h.

Referenced by SDL_Convert_F32LSB_to_S16MSB(), SDL_Convert_F32MSB_to_S16MSB(), SDL_Convert_S16LSB_to_S16MSB(), SDL_Convert_S32LSB_to_S16MSB(), SDL_Convert_S32MSB_to_S16MSB(), SDL_Convert_S8_to_S16MSB(), SDL_Convert_U16LSB_to_S16MSB(), SDL_Convert_U16MSB_to_S16MSB(), SDL_Convert_U8_to_S16MSB(), SDL_MixAudioFormat(), and SDLTest_CommonArg().

#define AUDIO_S16SYS AUDIO_S16LSB

Definition at line 123 of file SDL_audio.h.

Referenced by audio_initOpenCloseQuitAudio(), audio_lockUnlockOpenAudioDevice(), audio_openCloseAndGetAudioStatus(), audio_openCloseAudioDeviceConnected(), and audio_pauseUnpauseAudio().

#define AUDIO_S32 AUDIO_S32LSB

Definition at line 105 of file SDL_audio.h.

Referenced by SDL_ConvertMono(), SDL_ConvertSurround(), SDL_ConvertSurround_4(), and SDL_LoadWAV_RW().

#define AUDIO_S32LSB 0x8020

32-bit integer samples

Definition at line 103 of file SDL_audio.h.

Referenced by SDL_Convert_F32LSB_to_S32LSB(), SDL_Convert_F32MSB_to_S32LSB(), SDL_Convert_S16LSB_to_S32LSB(), SDL_Convert_S16MSB_to_S32LSB(), SDL_Convert_S32MSB_to_S32LSB(), SDL_Convert_S8_to_S32LSB(), SDL_Convert_U16LSB_to_S32LSB(), SDL_Convert_U16MSB_to_S32LSB(), SDL_Convert_U8_to_S32LSB(), and SDL_MixAudioFormat().

#define AUDIO_S32MSB 0x9020

As above, but big-endian byte order

Definition at line 104 of file SDL_audio.h.

Referenced by SDL_Convert_F32LSB_to_S32MSB(), SDL_Convert_F32MSB_to_S32MSB(), SDL_Convert_S16LSB_to_S32MSB(), SDL_Convert_S16MSB_to_S32MSB(), SDL_Convert_S32LSB_to_S32MSB(), SDL_Convert_S8_to_S32MSB(), SDL_Convert_U16LSB_to_S32MSB(), SDL_Convert_U16MSB_to_S32MSB(), SDL_Convert_U8_to_S32MSB(), and SDL_MixAudioFormat().

#define AUDIO_S32SYS AUDIO_S32LSB

Definition at line 124 of file SDL_audio.h.

#define AUDIO_S8 0x8008

Signed 8-bit samples

Definition at line 90 of file SDL_audio.h.

Referenced by audio_buildAudioCVT(), audio_buildAudioCVTNegative(), SDL_Convert_F32LSB_to_S8(), SDL_Convert_F32MSB_to_S8(), SDL_Convert_S16LSB_to_S8(), SDL_Convert_S16MSB_to_S8(), SDL_Convert_S32LSB_to_S8(), SDL_Convert_S32MSB_to_S8(), SDL_Convert_U16LSB_to_S8(), SDL_Convert_U16MSB_to_S8(), SDL_Convert_U8_to_S8(), SDL_ConvertMono(), SDL_ConvertSurround(), SDL_ConvertSurround_4(), SDL_MixAudioFormat(), and SDLTest_CommonArg().

#define AUDIO_U16 AUDIO_U16LSB

Definition at line 95 of file SDL_audio.h.

Referenced by SDL_ConvertMono(), SDL_ConvertSurround(), SDL_ConvertSurround_4(), and SDLTest_CommonArg().

#define AUDIO_U16LSB 0x0010

Unsigned 16-bit samples

Definition at line 91 of file SDL_audio.h.

Referenced by SDL_Convert_F32LSB_to_U16LSB(), SDL_Convert_F32MSB_to_U16LSB(), SDL_Convert_S16LSB_to_U16LSB(), SDL_Convert_S16MSB_to_U16LSB(), SDL_Convert_S32LSB_to_U16LSB(), SDL_Convert_S32MSB_to_U16LSB(), SDL_Convert_S8_to_U16LSB(), SDL_Convert_U16MSB_to_U16LSB(), SDL_Convert_U8_to_U16LSB(), and SDLTest_CommonArg().

#define AUDIO_U16MSB 0x1010

As above, but big-endian byte order

Definition at line 93 of file SDL_audio.h.

Referenced by SDL_Convert_F32LSB_to_U16MSB(), SDL_Convert_F32MSB_to_U16MSB(), SDL_Convert_S16LSB_to_U16MSB(), SDL_Convert_S16MSB_to_U16MSB(), SDL_Convert_S32LSB_to_U16MSB(), SDL_Convert_S32MSB_to_U16MSB(), SDL_Convert_S8_to_U16MSB(), SDL_Convert_U16LSB_to_U16MSB(), SDL_Convert_U8_to_U16MSB(), and SDLTest_CommonArg().

#define AUDIO_U16SYS AUDIO_U16LSB

Definition at line 122 of file SDL_audio.h.

#define AUDIO_U8 0x0008

Unsigned 8-bit samples

Definition at line 89 of file SDL_audio.h.

Referenced by SDL_CalculateAudioSpec(), SDL_Convert_F32LSB_to_U8(), SDL_Convert_F32MSB_to_U8(), SDL_Convert_S16LSB_to_U8(), SDL_Convert_S16MSB_to_U8(), SDL_Convert_S32LSB_to_U8(), SDL_Convert_S32MSB_to_U8(), SDL_Convert_S8_to_U8(), SDL_Convert_U16LSB_to_U8(), SDL_Convert_U16MSB_to_U8(), SDL_ConvertMono(), SDL_ConvertSurround(), SDL_ConvertSurround_4(), SDL_LoadWAV_RW(), SDL_MixAudioFormat(), and SDLTest_CommonArg().

#define SDL_AUDIO_ALLOW_ANY_CHANGE (SDL_AUDIO_ALLOW_FREQUENCY_CHANGE|SDL_AUDIO_ALLOW_FORMAT_CHANGE|SDL_AUDIO_ALLOW_CHANNELS_CHANGE)

Definition at line 143 of file SDL_audio.h.

Referenced by audio_lockUnlockOpenAudioDevice(), audio_openCloseAndGetAudioStatus(), audio_openCloseAudioDeviceConnected(), and SDL_OpenAudio().

#define SDL_AUDIO_ALLOW_CHANNELS_CHANGE 0x00000004

Definition at line 142 of file SDL_audio.h.

Referenced by open_audio_device().

#define SDL_AUDIO_ALLOW_FORMAT_CHANGE 0x00000002

Definition at line 141 of file SDL_audio.h.

Referenced by open_audio_device().

#define SDL_AUDIO_ALLOW_FREQUENCY_CHANGE 0x00000001

Definition at line 140 of file SDL_audio.h.

Referenced by open_audio_device().

#define SDL_AUDIO_BITSIZE | ( |  | x | ) | (x & SDL_AUDIO_MASK_BITSIZE)

Definition at line 75 of file SDL_audio.h.

Referenced by main(), SDL_BuildAudioCVT(), SDL_BuildAudioTypeCVT(), SDL_CalculateAudioSpec(), SDL_ConvertStereo(), SDL_ConvertStrip(), SDL_ConvertStrip_2(), and SDL_LoadWAV_RW().

#define SDL_AUDIO_ISBIGENDIAN | ( |  | x | ) | (x & SDL_AUDIO_MASK_ENDIAN)

Definition at line 77 of file SDL_audio.h.

Referenced by SDL_ConvertMono(), SDL_ConvertSurround(), and SDL_ConvertSurround_4().

#define SDL_AUDIO_ISFLOAT | ( |  | x | ) | (x & SDL_AUDIO_MASK_DATATYPE)

Definition at line 76 of file SDL_audio.h.

#define SDL_AUDIO_ISINT | ( |  | x | ) | (!SDL_AUDIO_ISFLOAT(x))

Definition at line 79 of file SDL_audio.h.

#define SDL_AUDIO_ISLITTLEENDIAN | ( |  | x | ) | (!SDL_AUDIO_ISBIGENDIAN(x))

Definition at line 80 of file SDL_audio.h.

#define SDL_AUDIO_ISSIGNED | ( |  | x | ) | (x & SDL_AUDIO_MASK_SIGNED)

Definition at line 78 of file SDL_audio.h.

Referenced by SDL_BuildAudioCVT().

#define SDL_AUDIO_ISUNSIGNED | ( |  | x | ) | (!SDL_AUDIO_ISSIGNED(x))

Definition at line 81 of file SDL_audio.h.

#define SDL_AUDIO_MASK_BITSIZE (0xFF)

Definition at line 71 of file SDL_audio.h.

Referenced by SDL_ConvertMono(), SDL_ConvertSurround(), and SDL_ConvertSurround_4().

#define SDL_AUDIO_MASK_DATATYPE (1<<8)

Definition at line 72 of file SDL_audio.h.

Referenced by SDL_ConvertMono(), SDL_ConvertSurround(), and SDL_ConvertSurround_4().

#define SDL_AUDIO_MASK_ENDIAN (1<<12)

Definition at line 73 of file SDL_audio.h.

#define SDL_AUDIO_MASK_SIGNED (1<<15)

Definition at line 74 of file SDL_audio.h.

Referenced by SDL_ConvertMono(), SDL_ConvertSurround(), and SDL_ConvertSurround_4().

#define SDL_AUDIOCVT_PACKED

A structure to hold a set of audio conversion filters and buffers.

Definition at line 197 of file SDL_audio.h.

#define SDL_LoadWAV | ( |  | file,
|  |  | spec,
|  |  | audio_buf,
|  |  | audio_len
| ) |  | SDL_LoadWAV_RW(SDL_RWFromFile(file, "rb"),1, spec,audio_buf,audio_len)

Loads a WAV from a file. Compatibility convenience function.

Definition at line 424 of file SDL_audio.h.

Referenced by main().

#define SDL_MIX_MAXVOLUME 128

Definition at line 461 of file SDL_audio.h.

Referenced by SDL_MixAudioFormat().

## Typedef Documentation

typedef void( * SDL_AudioCallback) (void *userdata, Uint8 *stream, int len)

This function is called when the audio device needs more data.

Parameters

  userdata | An application-specific parameter saved in the SDL_AudioSpec structure
  stream | A pointer to the audio data buffer.
  len | The length of that buffer in bytes.

Once the callback returns, the buffer will no longer be valid. Stereo samples are stored in a LRLRLR ordering.

You can choose to avoid callbacks and use SDL_QueueAudio() instead, if you like. Just open your audio device with a NULL callback.

Definition at line 162 of file SDL_audio.h.

SDL_PRINTF_FORMAT_STRING const char int SDL_PRINTF_FORMAT_STRING const char int SDL_PRINTF_FORMAT_STRING const char int SDL_PRINTF_FORMAT_STRING const char const char SDL_SCANF_FORMAT_STRING const char return SDL_ThreadFunction const char void return Uint32 return Uint32 SDL_AssertionHandler void SDL_SpinLock SDL_atomic_t int int return SDL_atomic_t return void void void return void return int return SDL_AudioSpec SDL_AudioSpec return int int return return int SDL_RWops int SDL_AudioSpec Uint8 Uint32 return SDL_AudioCVT SDL_AudioFormat Uint8 int SDL_AudioFormat Uint8 int return Uint8 const Uint8 Uint32 int const char return return return return return return return return Uint32 return Uint32 SDL_Event return SDL_Event int return SDL_EventFilter void SDL_EventFilter void SDL_EventFilter void int return const char const char return SDL_JoystickGUID return int return int return SDL_GameController return int return const char return SDL_GameController SDL_GameControllerAxis return const char return SDL_GameController SDL_GameControllerButton return SDL_GameController SDL_RWops return SDL_TouchID SDL_RWops return int return int return return SDL_Joystick return SDL_Haptic SDL_Haptic return SDL_Haptic return SDL_Haptic SDL_HapticEffect return SDL_Haptic int Uint32 return SDL_Haptic int SDL_Haptic int return SDL_Haptic return SDL_Haptic return SDL_Haptic return SDL_Haptic return const char const char return const char SDL_HintCallback void int return SDL_Joystick return SDL_Joystick return const char return SDL_Joystick return SDL_Joystick return SDL_Joystick return int return SDL_Joystick int return SDL_Joystick int return return return SDL_Scancode return SDL_Scancode return SDL_Keycode return return const char return void int SDL_LogPriority SDL_LogOutputFunction void Uint32 const char const char SDL_Window return int int return SDL_Window int int return SDL_Surface int int return SDL_Cursor return int return SDL_mutex return SDL_mutex return Uint32 return SDL_sem return SDL_sem Uint32 return SDL_sem return SDL_cond SDL_cond return SDL_cond SDL_mutex Uint32 return Uint32 int Uint32 Uint32 Uint32 Uint32 return Uint32 return int return SDL_Palette const SDL_Color int int return const SDL_PixelFormat Uint8 Uint8 Uint8 return Uint32 const SDL_PixelFormat Uint8 Uint8 Uint8 float Uint16 int int return const SDL_Rect const SDL_Rect SDL_Rect return const SDL_Point int const SDL_Rect SDL_Rect return return int int Uint32 SDL_Window SDL_Renderer return SDL_Surface return SDL_Renderer SDL_RendererInfo return SDL_Renderer Uint32 int int int return SDL_Texture Uint32 int int int return SDL_Texture Uint8 Uint8 Uint8 return SDL_Texture Uint8 return SDL_Texture SDL_BlendMode return SDL_Texture const SDL_Rect const Uint8 int const Uint8 int const Uint8 int return SDL_Texture SDL_Renderer SDL_Texture return SDL_Renderer int int return SDL_Renderer const SDL_Rect return SDL_Renderer const SDL_Rect return SDL_Renderer float float return SDL_Renderer Uint8 Uint8 Uint8 Uint8 return SDL_Renderer SDL_BlendMode return SDL_Renderer return SDL_Renderer const SDL_Point int return SDL_Renderer const SDL_Point int return SDL_Renderer const SDL_Rect int return SDL_Renderer const SDL_Rect int return SDL_Renderer SDL_Texture const SDL_Rect const SDL_Rect const double const SDL_Point const SDL_RendererFlip return SDL_Renderer SDL_Renderer SDL_Texture return void int return return SDL_RWops return SDL_RWops return SDL_RWops return SDL_RWops return SDL_RWops Uint16 return SDL_RWops Uint32 return SDL_RWops Uint64 return const char unsigned int unsigned int unsigned int unsigned int Uint32 return SDL_Window SDL_Surface SDL_WindowShapeMode return size_t return void size_t return const char return void size_t size_t int(*) SDL_DYNAPI_PROC int return int return int size_t return size_t return const wchar_t return const wchar_t size_t return const char size_t return const char size_t return char return char return const char int return int char int return long char int return Sint64 char int return const char return const char char int return const char char int return const char char return const char const char size_t return const char const char size_t return double return double return double return double return double return double return double int return float return const char const char return SDL_iconv_t const char size_t char size_t return Uint32 int int int Uint32 Uint32 Uint32 Uint32 return SDL_Surface SDL_Surface return SDL_RWops int return SDL_Surface int return SDL_Surface Uint32 return SDL_Surface Uint8 Uint8 Uint8 return SDL_Surface Uint8 return SDL_Surface SDL_BlendMode return SDL_Surface SDL_Rect SDL_Surface Uint32 Uint32 return SDL_Surface const SDL_Rect Uint32 return SDL_Surface const SDL_Rect SDL_Surface SDL_Rect return SDL_Surface const SDL_Rect SDL_Surface const SDL_Rect return SDL_Surface SDL_Rect SDL_Surface SDL_Rect return SDL_Thread return SDL_Thread return SDL_Thread int return SDL_TLSID const void void(*) return return Uint32 SDL_TimerID return int return SDL_TouchID int return return return const char return return int return int return int SDL_DisplayMode return int const SDL_DisplayMode SDL_DisplayMode return SDL_Window const SDL_DisplayMode return SDL_Window return const void return Uint32 return SDL_Window const char SDL_Window SDL_Surface SDL_Window const char return SDL_Window int int SDL_Window int int SDL_Window int int SDL_Window int int SDL_Window SDL_Window SDL_Window SDL_Window Uint32 return SDL_Window return SDL_Window SDL_bool SDL_Window float return SDL_Window const Uint16 const Uint16 const Uint16 return SDL_Window const char return SDL_GLattr int return SDL_Window return return SDL_Window int int return SDL_GLContext SDL_RWops int return return void return int int return double return SDL_bool return int int return SDL_AudioDeviceID const void Uint32 return SDL_AudioDeviceID(SDL_Window *, SDL_GetGrabbedWindow,(void),(), return) SDL_DYNAPI_PROC(int

SDL Audio Device IDs.

A successful call to SDL_OpenAudio() is always device id 1, and legacy SDL audio APIs assume you want this device ID. SDL_OpenAudioDevice() calls always returns devices >= 2 on success. The legacy calls are good both for backwards compatibility and when you don't care about multiple, specific, or capture devices.

Definition at line 303 of file SDL_audio.h.

typedef void( * SDL_AudioFilter) (struct SDL_AudioCVT *cvt, SDL_AudioFormat format)

Definition at line 183 of file SDL_audio.h.

typedef Uint16 SDL_AudioFormat

Audio format flags.

These are what the 16 bits in SDL_AudioFormat currently mean... (Unspecified bits are always zero).

    ++-----------------------sample is signed if set
    ||
    ||       ++-----------sample is bigendian if set
    ||       ||
    ||       ||          ++---sample is float if set
    ||       ||          ||
    ||       ||          || +---sample bit size---+
    ||       ||          || |                     |
    15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00

There are macros in SDL 2.0 and later to query these bits.

Definition at line 64 of file SDL_audio.h.

## Enumeration Type Documentation

enum SDL_AudioStatus

Enumerator
SDL_AUDIO_STOPPED |
SDL_AUDIO_PLAYING |
SDL_AUDIO_PAUSED |

Definition at line 368 of file SDL_audio.h.

{
SDL_AUDIO_STOPPED = 0,
SDL_AUDIO_PLAYING,
SDL_AUDIO_PAUSED
} SDL_AudioStatus;
SDL_AudioStatus
SDL_AudioStatus
Definition: SDL_audio.h:368
SDL_AUDIO_PAUSED
Definition: SDL_audio.h:372
SDL_AUDIO_STOPPED
Definition: SDL_audio.h:370
SDL_AUDIO_PLAYING
Definition: SDL_audio.h:371

## Function Documentation

int SDL_AudioInit | ( | const char * | driver_name | ) |

Definition at line 711 of file SDL_audio.c.

References AudioBootStrap::demand_only, SDL_AudioDriver::desc, AudioBootStrap::desc, SDL_AudioDriverImpl::DetectDevices, SDL_AudioDriver::detectionLock, finalize_audio_entry_points(), i, SDL_AudioDriver::impl, AudioBootStrap::init, SDL_AudioDriver::name, AudioBootStrap::name, NULL, SDL_AudioQuit(), SDL_CreateMutex, SDL_getenv, SDL_INIT_AUDIO, SDL_SetError, SDL_strlen, SDL_strncasecmp, SDL_WasInit, and SDL_zero.

{
int i = 0;
int initialized = 0;
int tried_to_init = 0;
if (SDL_WasInit(SDL_INIT_AUDIO)) {
SDL_AudioQuit(); /* shutdown driver if already running. */
}
SDL_zero(current_audio);
SDL_zero(open_devices);
/* Select the proper audio driver */
if (driver_name == NULL) {
driver_name = SDL_getenv("SDL_AUDIODRIVER");
}
for (i = 0; (!initialized) && (bootstrap[i]); ++i) {
/* make sure we should even try this driver before doing so... */
const AudioBootStrap *backend = bootstrap[i];
if ((driver_name && (SDL_strncasecmp(backend->name, driver_name, SDL_strlen(driver_name)) != 0)) ||
(!driver_name && backend->demand_only)) {
continue;
}
tried_to_init = 1;
SDL_zero(current_audio);
current_audio.name = backend->name;
current_audio.desc = backend->desc;
initialized = backend->init(&current_audio.impl);
}
if (!initialized) {
/* specific drivers will set the error message if they fail... */
if (!tried_to_init) {
if (driver_name) {
SDL_SetError("Audio target '%s' not available", driver_name);
} else {
SDL_SetError("No available audio device");
}
}
SDL_zero(current_audio);
return -1; /* No driver was available, so fail. */
}
current_audio.detectionLock = SDL_CreateMutex();
finalize_audio_entry_points();
/* Make sure we have a list of devices available at startup. */
current_audio.impl.DetectDevices();
return 0;
}
open_devices
static SDL_AudioDevice * open_devices[16]
Definition: SDL_audio.c:34
SDL_AudioDriver::name
const char * name
Definition: SDL_sysaudio.h:114
SDL_AudioDriverImpl::DetectDevices
void(* DetectDevices)(void)
Definition: SDL_sysaudio.h:71
AudioBootStrap::name
const char * name
Definition: SDL_sysaudio.h:191
SDL_CreateMutex
#define SDL_CreateMutex
Definition: SDL_dynapi_overrides.h:265
current_audio
static SDL_AudioDriver current_audio
Definition: SDL_audio.c:33
SDL_strncasecmp
#define SDL_strncasecmp
Definition: SDL_dynapi_overrides.h:426
finalize_audio_entry_points
static void finalize_audio_entry_points(void)
Definition: SDL_audio.c:262
SDL_AudioDriver::detectionLock
SDL_mutex * detectionLock
Definition: SDL_sysaudio.h:123
AudioBootStrap
Definition: SDL_sysaudio.h:189
SDL_AudioDriver::desc
const char * desc
Definition: SDL_sysaudio.h:118
SDL_AudioQuit
void SDL_AudioQuit(void)
Definition: SDL_audio.c:1345
SDL_zero
#define SDL_zero(x)
Definition: SDL_stdinc.h:355
SDL_getenv
#define SDL_getenv
Definition: SDL_dynapi_overrides.h:384
i
return Display return Display Bool Bool int int int return Display XEvent Bool(*) XPointer return Display return Display Drawable _Xconst char unsigned int unsigned int return Display Pixmap Pixmap XColor XColor unsigned int unsigned int return Display _Xconst char char int char return Display Visual unsigned int int int char unsigned int unsigned int in i)
Definition: SDL_x11sym.h:42
bootstrap
static const AudioBootStrap *const bootstrap[]
Definition: SDL_audio.c:76
NULL
#define NULL
Definition: begin_code.h:143
SDL_SetError
#define SDL_SetError
Definition: SDL_dynapi_overrides.h:36
SDL_INIT_AUDIO
#define SDL_INIT_AUDIO
Definition: SDL.h:76
SDL_AudioDriver::impl
SDL_AudioDriverImpl impl
Definition: SDL_sysaudio.h:120
SDL_strlen
#define SDL_strlen
Definition: SDL_dynapi_overrides.h:399
AudioBootStrap::demand_only
int demand_only
Definition: SDL_sysaudio.h:194
AudioBootStrap::init
int(* init)(SDL_AudioDriverImpl *impl)
Definition: SDL_sysaudio.h:193
AudioBootStrap::desc
const char * desc
Definition: SDL_sysaudio.h:192
SDL_WasInit
#define SDL_WasInit
Definition: SDL_dynapi_overrides.h:63

void SDL_AudioQuit | ( | void |  | ) |

Definition at line 1345 of file SDL_audio.c.

References SDL_AudioDriverImpl::Deinitialize, SDL_AudioDriver::detectionLock, free_device_list(), i, SDL_AudioDriver::impl, SDL_AudioDriver::inputDeviceCount, SDL_AudioDriver::inputDevices, SDL_AudioDriver::name, NULL, SDL_AudioDriver::outputDeviceCount, SDL_AudioDriver::outputDevices, SDL_arraysize, SDL_CloseAudioDevice(), SDL_DestroyMutex, and SDL_zero.

Referenced by SDL_AudioInit().

{
SDL_AudioDeviceID i;
if (!current_audio.name) { /* not initialized?! */
return;
}
for (i = 0; i < SDL_arraysize(open_devices); i++) {
if (open_devices[i] != NULL) {
SDL_CloseAudioDevice(i+1);
}
}
free_device_list(&current_audio.outputDevices, &current_audio.outputDeviceCount);
free_device_list(&current_audio.inputDevices, &current_audio.inputDeviceCount);
/* Free the driver data */
current_audio.impl.Deinitialize();
SDL_DestroyMutex(current_audio.detectionLock);
SDL_zero(current_audio);
SDL_zero(open_devices);
}
open_devices
static SDL_AudioDevice * open_devices[16]
Definition: SDL_audio.c:34
SDL_AudioDriver::name
const char * name
Definition: SDL_sysaudio.h:114
SDL_AudioDriver::inputDeviceCount
int inputDeviceCount
Definition: SDL_sysaudio.h:127
current_audio
static SDL_AudioDriver current_audio
Definition: SDL_audio.c:33
SDL_AudioDriver::detectionLock
SDL_mutex * detectionLock
Definition: SDL_sysaudio.h:123
SDL_AudioDriverImpl::Deinitialize
void(* Deinitialize)(void)
Definition: SDL_sysaudio.h:83
SDL_zero
#define SDL_zero(x)
Definition: SDL_stdinc.h:355
SDL_AudioDriver::outputDevices
SDL_AudioDeviceItem * outputDevices
Definition: SDL_sysaudio.h:128
i
return Display return Display Bool Bool int int int return Display XEvent Bool(*) XPointer return Display return Display Drawable _Xconst char unsigned int unsigned int return Display Pixmap Pixmap XColor XColor unsigned int unsigned int return Display _Xconst char char int char return Display Visual unsigned int int int char unsigned int unsigned int in i)
Definition: SDL_x11sym.h:42
NULL
#define NULL
Definition: begin_code.h:143
free_device_list
static void free_device_list(SDL_AudioDeviceItem **devices, int *devCount)
Definition: SDL_audio.c:330
SDL_DestroyMutex
#define SDL_DestroyMutex
Definition: SDL_dynapi_overrides.h:269
SDL_AudioDeviceID
Uint32 SDL_AudioDeviceID
Definition: SDL_audio.h:303
SDL_AudioDriver::impl
SDL_AudioDriverImpl impl
Definition: SDL_sysaudio.h:120
SDL_AudioDriver::outputDeviceCount
int outputDeviceCount
Definition: SDL_sysaudio.h:126
SDL_arraysize
#define SDL_arraysize(array)
Definition: SDL_stdinc.h:93
SDL_CloseAudioDevice
void SDL_CloseAudioDevice(SDL_AudioDeviceID devid)
Definition: SDL_audio.c:1329
SDL_AudioDriver::inputDevices
SDL_AudioDeviceItem * inputDevices
Definition: SDL_sysaudio.h:129

int SDL_BuildAudioCVT | ( | SDL_AudioCVT * | cvt,
|  | SDL_AudioFormat | src_format,
|  | Uint8 | src_channels,
|  | int | src_rate,
|  | SDL_AudioFormat | dst_format,
|  | Uint8 | dst_channels,
|  | int | dst_rate
| ) |  |

This function takes a source format and rate and a destination format and rate, and initializes the `cvt` structure with information needed by SDL_ConvertAudio() to convert a buffer of audio data from one format to the other.

Returns
  -1 if the format conversion is not supported, 0 if there's no conversion needed, or 1 if the audio filter is set up.

Definition at line 998 of file SDL_audiocvt.c.

References SDL_AudioCVT::buf, SDL_AudioCVT::dst_format, SDL_AudioCVT::filter_index, SDL_AudioCVT::filters, SDL_AudioCVT::len, SDL_AudioCVT::len_mult, SDL_AudioCVT::len_ratio, SDL_AudioCVT::needed, NULL, SDL_AudioCVT::rate_incr, SDL_AUDIO_BITSIZE, SDL_AUDIO_ISSIGNED, SDL_BuildAudioResampleCVT(), SDL_BuildAudioTypeCVT(), SDL_ConvertMono(), SDL_ConvertStereo(), SDL_ConvertStrip(), SDL_ConvertStrip_2(), SDL_ConvertSurround(), SDL_ConvertSurround_4(), SDL_InvalidParamError, SDL_SetError, SDL_zerop, and SDL_AudioCVT::src_format.

{
/*
* !!! FIXME: reorder filters based on which grow/shrink the buffer.
* !!! FIXME: ideally, we should do everything that shrinks the buffer
* !!! FIXME: first, so we don't have to process as many bytes in a given
* !!! FIXME: filter and abuse the CPU cache less. This might not be as
* !!! FIXME: good in practice as it sounds in theory, though.
*/
/* Sanity check target pointer */
if (cvt == NULL) {
return SDL_InvalidParamError("cvt");
}
/* there are no unsigned types over 16 bits, so catch this up front. */
if ((SDL_AUDIO_BITSIZE(src_fmt) > 16) && (!SDL_AUDIO_ISSIGNED(src_fmt))) {
return SDL_SetError("Invalid source format");
}
if ((SDL_AUDIO_BITSIZE(dst_fmt) > 16) && (!SDL_AUDIO_ISSIGNED(dst_fmt))) {
return SDL_SetError("Invalid destination format");
}
/* prevent possible divisions by zero, etc. */
if ((src_channels == 0) || (dst_channels == 0)) {
return SDL_SetError("Source or destination channels is zero");
}
if ((src_rate == 0) || (dst_rate == 0)) {
return SDL_SetError("Source or destination rate is zero");
}
#ifdef DEBUG_CONVERT
printf("Build format %04x->%04x, channels %u->%u, rate %d->%d\n",
src_fmt, dst_fmt, src_channels, dst_channels, src_rate, dst_rate);
#endif
/* Start off with no conversion necessary */
SDL_zerop(cvt);
cvt->src_format = src_fmt;
cvt->dst_format = dst_fmt;
cvt->needed = 0;
cvt->filter_index = 0;
cvt->filters[0] = NULL;
cvt->len_mult = 1;
cvt->len_ratio = 1.0;
cvt->rate_incr = ((double) dst_rate) / ((double) src_rate);
/* Convert data types, if necessary. Updates (cvt). */
if (SDL_BuildAudioTypeCVT(cvt, src_fmt, dst_fmt) == -1) {
return -1; /* shouldn't happen, but just in case... */
}
/* Channel conversion */
if (src_channels != dst_channels) {
if ((src_channels == 1) && (dst_channels > 1)) {
cvt->filters[cvt->filter_index++] = SDL_ConvertStereo;
cvt->len_mult *= 2;
src_channels = 2;
cvt->len_ratio *= 2;
}
if ((src_channels == 2) && (dst_channels == 6)) {
cvt->filters[cvt->filter_index++] = SDL_ConvertSurround;
src_channels = 6;
cvt->len_mult *= 3;
cvt->len_ratio *= 3;
}
if ((src_channels == 2) && (dst_channels == 4)) {
cvt->filters[cvt->filter_index++] = SDL_ConvertSurround_4;
src_channels = 4;
cvt->len_mult *= 2;
cvt->len_ratio *= 2;
}
while ((src_channels * 2) <= dst_channels) {
cvt->filters[cvt->filter_index++] = SDL_ConvertStereo;
cvt->len_mult *= 2;
src_channels *= 2;
cvt->len_ratio *= 2;
}
if ((src_channels == 6) && (dst_channels <= 2)) {
cvt->filters[cvt->filter_index++] = SDL_ConvertStrip;
src_channels = 2;
cvt->len_ratio /= 3;
}
if ((src_channels == 6) && (dst_channels == 4)) {
cvt->filters[cvt->filter_index++] = SDL_ConvertStrip_2;
src_channels = 4;
cvt->len_ratio /= 2;
}
/* This assumes that 4 channel audio is in the format:
Left {front/back} + Right {front/back}
so converting to L/R stereo works properly.
*/
while (((src_channels % 2) == 0) &&
((src_channels / 2) >= dst_channels)) {
cvt->filters[cvt->filter_index++] = SDL_ConvertMono;
src_channels /= 2;
cvt->len_ratio /= 2;
}
if (src_channels != dst_channels) {
/* Uh oh.. */ ;
}
}
/* Do rate conversion, if necessary. Updates (cvt). */
if (SDL_BuildAudioResampleCVT(cvt, dst_channels, src_rate, dst_rate) ==
-1) {
return -1; /* shouldn't happen, but just in case... */
}
/* Set up the filter information */
if (cvt->filter_index != 0) {
cvt->needed = 1;
cvt->src_format = src_fmt;
cvt->dst_format = dst_fmt;
cvt->len = 0;
cvt->buf = NULL;
cvt->filters[cvt->filter_index] = NULL;
}
return (cvt->needed);
}
SDL_AudioCVT::len
int len
Definition: SDL_audio.h:207
SDL_AudioCVT::buf
Uint8 * buf
Definition: SDL_audio.h:206
SDL_AudioCVT::filter_index
int filter_index
Definition: SDL_audio.h:212
SDL_AudioCVT::len_ratio
double len_ratio
Definition: SDL_audio.h:210
SDL_AUDIO_ISSIGNED
#define SDL_AUDIO_ISSIGNED(x)
Definition: SDL_audio.h:78
SDL_AudioCVT::len_mult
int len_mult
Definition: SDL_audio.h:209
SDL_InvalidParamError
#define SDL_InvalidParamError(param)
Definition: SDL_error.h:54
SDL_zerop
#define SDL_zerop(x)
Definition: SDL_stdinc.h:356
SDL_BuildAudioResampleCVT
static int SDL_BuildAudioResampleCVT(SDL_AudioCVT *cvt, int dst_channels, int src_rate, int dst_rate)
Definition: SDL_audiocvt.c:944
SDL_ConvertStrip_2
static void SDL_ConvertStrip_2(SDL_AudioCVT *cvt, SDL_AudioFormat format)
Definition: SDL_audiocvt.c:239
SDL_AudioCVT::filters
SDL_AudioFilter filters[10]
Definition: SDL_audio.h:211
SDL_AUDIO_BITSIZE
#define SDL_AUDIO_BITSIZE(x)
Definition: SDL_audio.h:75
SDL_AudioCVT::needed
int needed
Definition: SDL_audio.h:202
SDL_AudioCVT::src_format
SDL_AudioFormat src_format
Definition: SDL_audio.h:203
SDL_ConvertSurround
static void SDL_ConvertSurround(SDL_AudioCVT *cvt, SDL_AudioFormat format)
Definition: SDL_audiocvt.c:328
NULL
#define NULL
Definition: begin_code.h:143
SDL_ConvertStereo
static void SDL_ConvertStereo(SDL_AudioCVT *cvt, SDL_AudioFormat format)
Definition: SDL_audiocvt.c:285
SDL_SetError
#define SDL_SetError
Definition: SDL_dynapi_overrides.h:36
SDL_AudioCVT::dst_format
SDL_AudioFormat dst_format
Definition: SDL_audio.h:204
SDL_ConvertSurround_4
static void SDL_ConvertSurround_4(SDL_AudioCVT *cvt, SDL_AudioFormat format)
Definition: SDL_audiocvt.c:587
SDL_AudioCVT::rate_incr
double rate_incr
Definition: SDL_audio.h:205
SDL_ConvertMono
static void SDL_ConvertMono(SDL_AudioCVT *cvt, SDL_AudioFormat format)
Definition: SDL_audiocvt.c:34
SDL_ConvertStrip
static void SDL_ConvertStrip(SDL_AudioCVT *cvt, SDL_AudioFormat format)
Definition: SDL_audiocvt.c:195
SDL_BuildAudioTypeCVT
static int SDL_BuildAudioTypeCVT(SDL_AudioCVT *cvt, SDL_AudioFormat src_fmt, SDL_AudioFormat dst_fmt)
Definition: SDL_audiocvt.c:856

void SDL_ClearQueuedAudio | ( | SDL_AudioDeviceID | dev | ) |

Drop any queued audio data waiting to be sent to the hardware.

Immediately after this call, SDL_GetQueuedAudioSize() will return 0 and the hardware will start playing silence if more audio isn't queued.

This will not prevent playback of queued audio that's already been sent to the hardware, as we can not undo that, so expect there to be some fraction of a second of audio that might still be heard. This can be useful if you want to, say, drop any pending music during a level change in your game.

You may not queue audio on a device that is using an application-supplied callback; calling this function on such a device is always a no-op. You have to use the audio callback or queue audio with SDL_QueueAudio(), but not both.

You should not call SDL_LockAudio() on the device before clearing the queue; SDL handles locking internally for this function.

This function always succeeds and thus returns void.

Parameters

  dev | The device ID of which to clear the audio queue.

See also
  SDL_QueueAudio
  SDL_GetQueuedAudioSize

Definition at line 573 of file SDL_audio.c.

References SDL_AudioDevice::buffer_queue_head, SDL_AudioDevice::buffer_queue_tail, free_audio_queue(), get_audio_device(), SDL_AudioDriver::impl, SDL_AudioDriverImpl::LockDevice, NULL, SDL_AudioDevice::queued_bytes, SDLCALL, and SDL_AudioDriverImpl::UnlockDevice.

{
SDL_AudioDevice *device = get_audio_device(devid);
SDL_AudioBufferQueue *buffer = NULL;
if (!device) {
return; /* nothing to do. */
}
/* Blank out the device and release the mutex. Free it afterwards. */
current_audio.impl.LockDevice(device);
buffer = device->buffer_queue_head;
device->buffer_queue_tail = NULL;
device->buffer_queue_head = NULL;
device->queued_bytes = 0;
current_audio.impl.UnlockDevice(device);
free_audio_queue(buffer);
}
current_audio
static SDL_AudioDriver current_audio
Definition: SDL_audio.c:33
SDL_AudioDriverImpl::UnlockDevice
void(* UnlockDevice)(_THIS)
Definition: SDL_sysaudio.h:81
SDL_AudioDevice::queued_bytes
Uint32 queued_bytes
Definition: SDL_sysaudio.h:181
SDL_AudioDevice::buffer_queue_head
SDL_AudioBufferQueue * buffer_queue_head
Definition: SDL_sysaudio.h:178
SDL_AudioDevice::buffer_queue_tail
SDL_AudioBufferQueue * buffer_queue_tail
Definition: SDL_sysaudio.h:179
SDL_AudioBufferQueue
Definition: SDL_sysaudio.h:61
SDL_AudioDriverImpl::LockDevice
void(* LockDevice)(_THIS)
Definition: SDL_sysaudio.h:80
NULL
#define NULL
Definition: begin_code.h:143
free_audio_queue
static void free_audio_queue(SDL_AudioBufferQueue *buffer)
Definition: SDL_audio.c:423
SDL_AudioDriver::impl
SDL_AudioDriverImpl impl
Definition: SDL_sysaudio.h:120
SDL_AudioDevice
Definition: SDL_sysaudio.h:143
buffer
GLuint buffer
Definition: SDL_opengl_glext.h:533
get_audio_device
static SDL_AudioDevice * get_audio_device(SDL_AudioDeviceID id)
Definition: SDL_audio.c:150

void SDL_CloseAudio | ( | void |  | ) |

This function shuts down audio processing and closes the audio device.

Definition at line 1339 of file SDL_audio.c.

References SDL_CloseAudioDevice().

{
SDL_CloseAudioDevice(1);
}
SDL_CloseAudioDevice
void SDL_CloseAudioDevice(SDL_AudioDeviceID devid)
Definition: SDL_audio.c:1329

void SDL_CloseAudioDevice | ( | SDL_AudioDeviceID | dev | ) |

Definition at line 1329 of file SDL_audio.c.

References close_audio_device(), get_audio_device(), and NULL.

Referenced by open_audio_device(), SDL_AudioQuit(), and SDL_CloseAudio().

{
SDL_AudioDevice *device = get_audio_device(devid);
if (device) {
close_audio_device(device);
open_devices[devid - 1] = NULL;
}
}
open_devices
static SDL_AudioDevice * open_devices[16]
Definition: SDL_audio.c:34
NULL
#define NULL
Definition: begin_code.h:143
SDL_AudioDevice
Definition: SDL_sysaudio.h:143
get_audio_device
static SDL_AudioDevice * get_audio_device(SDL_AudioDeviceID id)
Definition: SDL_audio.c:150
close_audio_device
static void close_audio_device(SDL_AudioDevice *device)
Definition: SDL_audio.c:873

int SDL_ConvertAudio | ( | SDL_AudioCVT * | cvt | ) |

Once you have initialized the `cvt` structure using SDL_BuildAudioCVT(), created an audio buffer `cvt->buf`, and filled it with `cvt->len` bytes of audio data in the source format, this function will convert it in-place to the desired format.

The data conversion may expand the size of the audio data, so the buffer `cvt->buf` should be allocated after the `cvt` structure is initialized by SDL_BuildAudioCVT(), and should be `cvt->len*cvt->len_mult` bytes long.

Definition at line 814 of file SDL_audiocvt.c.

References SDL_AudioCVT::buf, SDL_AudioCVT::filter_index, SDL_AudioCVT::filters, SDL_AudioCVT::len, SDL_AudioCVT::len_cvt, NULL, SDL_SetError, and SDL_AudioCVT::src_format.

{
/* !!! FIXME: (cvt) should be const; stack-copy it here. */
/* !!! FIXME: (actually, we can't...len_cvt needs to be updated. Grr.) */
/* Make sure there's data to convert */
if (cvt->buf == NULL) {
SDL_SetError("No buffer allocated for conversion");
return (-1);
}
/* Return okay if no conversion is necessary */
cvt->len_cvt = cvt->len;
if (cvt->filters[0] == NULL) {
return (0);
}
/* Set up the conversion and go! */
cvt->filter_index = 0;
cvt->filters[0] (cvt, cvt->src_format);
return (0);
}
SDL_AudioCVT::len
int len
Definition: SDL_audio.h:207
SDL_AudioCVT::buf
Uint8 * buf
Definition: SDL_audio.h:206
SDL_AudioCVT::filter_index
int filter_index
Definition: SDL_audio.h:212
SDL_AudioCVT::filters
SDL_AudioFilter filters[10]
Definition: SDL_audio.h:211
SDL_AudioCVT::src_format
SDL_AudioFormat src_format
Definition: SDL_audio.h:203
SDL_AudioCVT::len_cvt
int len_cvt
Definition: SDL_audio.h:208
NULL
#define NULL
Definition: begin_code.h:143
SDL_SetError
#define SDL_SetError
Definition: SDL_dynapi_overrides.h:36

void SDL_FreeWAV | ( | Uint8 * | audio_buf | ) |

This function frees data previously allocated with SDL_LoadWAV_RW()

Definition at line 602 of file SDL_wave.c.

References SDL_free().

{
SDL_free(audio_buf);
}
SDL_free
void SDL_free(void *mem)

const char* SDL_GetAudioDeviceName | ( | int | index,
|  | int | iscapture
| ) |  |

Get the human-readable name of a specific audio device. Must be a value between 0 and (number of audio devices-1). Only valid after a successfully initializing the audio subsystem. The values returned by this function reflect the latest call to SDL_GetNumAudioDevices(); recall that function to redetect available hardware.

The string returned by this function is UTF-8 encoded, read-only, and managed internally. You are not to free it. If you need to keep the string for any length of time, you should make your own copy of it, as it will be invalid next time any of several other SDL functions is called.

Definition at line 833 of file SDL_audio.c.

References SDL_AudioDriver::detectionLock, SDL_AudioDriverImpl::HasCaptureSupport, i, SDL_AudioDriver::impl, SDL_AudioDriver::inputDeviceCount, SDL_AudioDriver::inputDevices, SDL_AudioDeviceItem::next, NULL, SDL_AudioDriver::outputDeviceCount, SDL_AudioDriver::outputDevices, retval, SDL_assert, SDL_INIT_AUDIO, SDL_LockMutex, SDL_SetError, SDL_UnlockMutex, and SDL_WasInit.

{
const char *retval = NULL;
if (!SDL_WasInit(SDL_INIT_AUDIO)) {
SDL_SetError("Audio subsystem is not initialized");
return NULL;
}
if ((iscapture) && (!current_audio.impl.HasCaptureSupport)) {
SDL_SetError("No capture support");
return NULL;
}
if (index >= 0) {
SDL_AudioDeviceItem *item;
int i;
SDL_LockMutex(current_audio.detectionLock);
item = iscapture ? current_audio.inputDevices : current_audio.outputDevices;
i = iscapture ? current_audio.inputDeviceCount : current_audio.outputDeviceCount;
if (index < i) {
for (i--; i > index; i--, item = item->next) {
SDL_assert(item != NULL);
}
SDL_assert(item != NULL);
retval = item->name;
}
SDL_UnlockMutex(current_audio.detectionLock);
}
if (retval == NULL) {
SDL_SetError("No such device");
}
return retval;
}
SDL_LockMutex
#define SDL_LockMutex
Definition: SDL_dynapi_overrides.h:266
SDL_AudioDeviceItem
Definition: SDL_sysaudio.h:98
SDL_AudioDeviceItem::next
struct SDL_AudioDeviceItem * next
Definition: SDL_sysaudio.h:101
SDL_AudioDriverImpl::HasCaptureSupport
int HasCaptureSupport
Definition: SDL_sysaudio.h:91
SDL_AudioDriver::inputDeviceCount
int inputDeviceCount
Definition: SDL_sysaudio.h:127
current_audio
static SDL_AudioDriver current_audio
Definition: SDL_audio.c:33
SDL_AudioDriver::detectionLock
SDL_mutex * detectionLock
Definition: SDL_sysaudio.h:123
retval
SDL_bool retval
Definition: testgamecontroller.c:65
index
GLuint index
Definition: SDL_opengl_glext.h:660
SDL_AudioDriver::outputDevices
SDL_AudioDeviceItem * outputDevices
Definition: SDL_sysaudio.h:128
i
return Display return Display Bool Bool int int int return Display XEvent Bool(*) XPointer return Display return Display Drawable _Xconst char unsigned int unsigned int return Display Pixmap Pixmap XColor XColor unsigned int unsigned int return Display _Xconst char char int char return Display Visual unsigned int int int char unsigned int unsigned int in i)
Definition: SDL_x11sym.h:42
SDL_assert
#define SDL_assert(condition)
Definition: SDL_assert.h:167
NULL
#define NULL
Definition: begin_code.h:143
SDL_SetError
#define SDL_SetError
Definition: SDL_dynapi_overrides.h:36
SDL_INIT_AUDIO
#define SDL_INIT_AUDIO
Definition: SDL.h:76
SDL_AudioDriver::impl
SDL_AudioDriverImpl impl
Definition: SDL_sysaudio.h:120
SDL_AudioDriver::outputDeviceCount
int outputDeviceCount
Definition: SDL_sysaudio.h:126
SDL_UnlockMutex
#define SDL_UnlockMutex
Definition: SDL_dynapi_overrides.h:268
SDL_WasInit
#define SDL_WasInit
Definition: SDL_dynapi_overrides.h:63
SDL_AudioDriver::inputDevices
SDL_AudioDeviceItem * inputDevices
Definition: SDL_sysaudio.h:129

SDL_AudioStatus SDL_GetAudioDeviceStatus | ( | SDL_AudioDeviceID | dev | ) |

Definition at line 1257 of file SDL_audio.c.

References SDL_AudioDevice::enabled, get_audio_device(), SDL_AudioDevice::paused, SDL_AUDIO_PAUSED, SDL_AUDIO_PLAYING, and SDL_AUDIO_STOPPED.

Referenced by SDL_GetAudioStatus().

{
SDL_AudioDevice *device = get_audio_device(devid);
SDL_AudioStatus status = SDL_AUDIO_STOPPED;
if (device && device->enabled) {
if (device->paused) {
status = SDL_AUDIO_PAUSED;
} else {
status = SDL_AUDIO_PLAYING;
}
}
return status;
}
SDL_AudioStatus
SDL_AudioStatus
Definition: SDL_audio.h:368
SDL_AUDIO_PAUSED
Definition: SDL_audio.h:372
SDL_AUDIO_STOPPED
Definition: SDL_audio.h:370
SDL_AudioDevice
Definition: SDL_sysaudio.h:143
SDL_AudioDevice::paused
int paused
Definition: SDL_sysaudio.h:164
SDL_AUDIO_PLAYING
Definition: SDL_audio.h:371
SDL_AudioDevice::enabled
int enabled
Definition: SDL_sysaudio.h:162
get_audio_device
static SDL_AudioDevice * get_audio_device(SDL_AudioDeviceID id)
Definition: SDL_audio.c:150

const char* SDL_GetAudioDriver | ( | int | index | ) |

Definition at line 702 of file SDL_audio.c.

References AudioBootStrap::name, NULL, and SDL_GetNumAudioDrivers().

{
if (index >= 0 && index < SDL_GetNumAudioDrivers()) {
return bootstrap[index]->name;
}
return NULL;
}
SDL_GetNumAudioDrivers
int SDL_GetNumAudioDrivers(void)
Definition: SDL_audio.c:696
AudioBootStrap::name
const char * name
Definition: SDL_sysaudio.h:191
index
GLuint index
Definition: SDL_opengl_glext.h:660
bootstrap
static const AudioBootStrap *const bootstrap[]
Definition: SDL_audio.c:76
NULL
#define NULL
Definition: begin_code.h:143

SDL_AudioStatus SDL_GetAudioStatus | ( | void |  | ) |

Definition at line 1273 of file SDL_audio.c.

References SDL_GetAudioDeviceStatus().

{
return SDL_GetAudioDeviceStatus(1);
}
SDL_GetAudioDeviceStatus
SDL_AudioStatus SDL_GetAudioDeviceStatus(SDL_AudioDeviceID devid)
Definition: SDL_audio.c:1257

const char* SDL_GetCurrentAudioDriver | ( | void |  | ) |

This function returns the name of the current audio driver, or NULL if no driver has been initialized.

Definition at line 772 of file SDL_audio.c.

References SDL_AudioDriver::name.

{
return current_audio.name;
}
SDL_AudioDriver::name
const char * name
Definition: SDL_sysaudio.h:114
current_audio
static SDL_AudioDriver current_audio
Definition: SDL_audio.c:33

int SDL_GetNumAudioDevices | ( | int | iscapture | ) |

Get the number of available devices exposed by the current driver. Only valid after a successfully initializing the audio subsystem. Returns -1 if an explicit list of devices can't be determined; this is not an error. For example, if SDL is set up to talk to a remote audio server, it can't list every one available on the Internet, but it will still allow a specific host to be specified to SDL_OpenAudioDevice().

In many common cases, when this function returns a value <= 0, it can still successfully open the default device (NULL for first argument of SDL_OpenAudioDevice()).

Definition at line 807 of file SDL_audio.c.

References SDL_AudioDriver::captureDevicesRemoved, clean_out_device_list(), SDL_AudioDriver::detectionLock, SDL_AudioDriver::inputDeviceCount, SDL_AudioDriver::inputDevices, SDL_AudioDriver::outputDeviceCount, SDL_AudioDriver::outputDevices, SDL_AudioDriver::outputDevicesRemoved, retval, SDL_FALSE, SDL_INIT_AUDIO, SDL_LockMutex, SDL_UnlockMutex, and SDL_WasInit.

{
int retval = 0;
if (!SDL_WasInit(SDL_INIT_AUDIO)) {
return -1;
}
SDL_LockMutex(current_audio.detectionLock);
if (iscapture && current_audio.captureDevicesRemoved) {
clean_out_device_list(&current_audio.inputDevices, &current_audio.inputDeviceCount, &current_audio.captureDevicesRemoved);
}
if (!iscapture && current_audio.outputDevicesRemoved) {
clean_out_device_list(&current_audio.outputDevices, &current_audio.outputDeviceCount, &current_audio.outputDevicesRemoved);
current_audio.outputDevicesRemoved = SDL_FALSE;
}
retval = iscapture ? current_audio.inputDeviceCount : current_audio.outputDeviceCount;
SDL_UnlockMutex(current_audio.detectionLock);
return retval;
}
SDL_LockMutex
#define SDL_LockMutex
Definition: SDL_dynapi_overrides.h:266
SDL_AudioDriver::captureDevicesRemoved
SDL_bool captureDevicesRemoved
Definition: SDL_sysaudio.h:124
clean_out_device_list
static void clean_out_device_list(SDL_AudioDeviceItem **devices, int *devCount, SDL_bool *removedFlag)
Definition: SDL_audio.c:779
SDL_AudioDriver::inputDeviceCount
int inputDeviceCount
Definition: SDL_sysaudio.h:127
current_audio
static SDL_AudioDriver current_audio
Definition: SDL_audio.c:33
SDL_AudioDriver::detectionLock
SDL_mutex * detectionLock
Definition: SDL_sysaudio.h:123
retval
SDL_bool retval
Definition: testgamecontroller.c:65
SDL_AudioDriver::outputDevices
SDL_AudioDeviceItem * outputDevices
Definition: SDL_sysaudio.h:128
SDL_AudioDriver::outputDevicesRemoved
SDL_bool outputDevicesRemoved
Definition: SDL_sysaudio.h:125
SDL_INIT_AUDIO
#define SDL_INIT_AUDIO
Definition: SDL.h:76
SDL_AudioDriver::outputDeviceCount
int outputDeviceCount
Definition: SDL_sysaudio.h:126
SDL_FALSE
Definition: SDL_stdinc.h:128
SDL_UnlockMutex
#define SDL_UnlockMutex
Definition: SDL_dynapi_overrides.h:268
SDL_WasInit
#define SDL_WasInit
Definition: SDL_dynapi_overrides.h:63
SDL_AudioDriver::inputDevices
SDL_AudioDeviceItem * inputDevices
Definition: SDL_sysaudio.h:129

int SDL_GetNumAudioDrivers | ( | void |  | ) |

Definition at line 696 of file SDL_audio.c.

References SDL_arraysize.

Referenced by SDL_GetAudioDriver().

{
return SDL_arraysize(bootstrap) - 1;
}
bootstrap
static const AudioBootStrap *const bootstrap[]
Definition: SDL_audio.c:76
SDL_arraysize
#define SDL_arraysize(array)
Definition: SDL_stdinc.h:93

Uint32 SDL_GetQueuedAudioSize | ( | SDL_AudioDeviceID | dev | ) |

Get the number of bytes of still-queued audio.

This is the number of bytes that have been queued for playback with SDL_QueueAudio(), but have not yet been sent to the hardware.

Once we've sent it to the hardware, this function can not decide the exact byte boundary of what has been played. It's possible that we just gave the hardware several kilobytes right before you called this function, but it hasn't played any of it yet, or maybe half of it, etc.

You may not queue audio on a device that is using an application-supplied callback; calling this function on such a device always returns 0. You have to use the audio callback or queue audio with SDL_QueueAudio(), but not both.

You should not call SDL_LockAudio() on the device before querying; SDL handles locking internally for this function.

Parameters

  dev | The device ID of which we will query queued audio size.

Returns
  Number of bytes (not samples!) of queued audio.

See also
  SDL_QueueAudio
  SDL_ClearQueuedAudio

Definition at line 557 of file SDL_audio.c.

References SDL_AudioSpec::callback, get_audio_device(), SDL_AudioDriverImpl::GetPendingBytes, SDL_AudioDriver::impl, SDL_AudioDriverImpl::LockDevice, SDL_AudioDevice::queued_bytes, retval, SDL_BufferQueueDrainCallback(), SDL_AudioDevice::spec, and SDL_AudioDriverImpl::UnlockDevice.

{
Uint32 retval = 0;
SDL_AudioDevice *device = get_audio_device(devid);
/* Nothing to do unless we're set up for queueing. */
if (device && (device->spec.callback == SDL_BufferQueueDrainCallback)) {
current_audio.impl.LockDevice(device);
retval = device->queued_bytes + current_audio.impl.GetPendingBytes(device);
current_audio.impl.UnlockDevice(device);
}
return retval;
}
Uint32
uint32_t Uint32
An unsigned 32-bit integer type.
Definition: SDL_stdinc.h:155
SDL_AudioDevice::spec
SDL_AudioSpec spec
Definition: SDL_sysaudio.h:150
current_audio
static SDL_AudioDriver current_audio
Definition: SDL_audio.c:33
SDL_AudioDriverImpl::UnlockDevice
void(* UnlockDevice)(_THIS)
Definition: SDL_sysaudio.h:81
SDL_AudioDevice::queued_bytes
Uint32 queued_bytes
Definition: SDL_sysaudio.h:181
retval
SDL_bool retval
Definition: testgamecontroller.c:65
SDL_AudioSpec::callback
SDL_AudioCallback callback
Definition: SDL_audio.h:177
SDL_AudioDriverImpl::LockDevice
void(* LockDevice)(_THIS)
Definition: SDL_sysaudio.h:80
SDL_AudioDriver::impl
SDL_AudioDriverImpl impl
Definition: SDL_sysaudio.h:120
SDL_AudioDevice
Definition: SDL_sysaudio.h:143
SDL_AudioDriverImpl::GetPendingBytes
int(* GetPendingBytes)(_THIS)
Definition: SDL_sysaudio.h:76
SDL_BufferQueueDrainCallback
static void SDL_BufferQueueDrainCallback(void *userdata, Uint8 *stream, int _len)
Definition: SDL_audio.c:433
get_audio_device
static SDL_AudioDevice * get_audio_device(SDL_AudioDeviceID id)
Definition: SDL_audio.c:150

SDL_AudioSpec* SDL_LoadWAV_RW | ( | SDL_RWops * | src,
|  | int | freesrc,
|  | SDL_AudioSpec * | spec,
|  | Uint8 ** | audio_buf,
|  | Uint32 * | audio_len
| ) |  |

This function loads a WAVE from the data source, automatically freeing that source if `freesrc` is non-zero. For example, to load a WAVE file, you could do:

SDL_LoadWAV_RW(SDL_RWFromFile("sample.wav", "rb"), 1, ...);

If this function succeeds, it returns the given SDL_AudioSpec, filled with the audio data format of the wave data, and sets `*audio_buf` to a malloc()'d buffer containing the audio data, and sets `*audio_len` to the length of that audio buffer, in bytes. You need to free the audio buffer with SDL_FreeWAV() when you are done with it.

This function returns NULL and sets the SDL error message if the wave file cannot be opened, uses an unknown data format, or is corrupt. Currently raw and MS-ADPCM WAVE files are supported.

Definition at line 407 of file SDL_wave.c.

References AUDIO_F32, AUDIO_S16, AUDIO_S32, AUDIO_U8, BEXT, WaveFMT::bitspersample, WaveFMT::channels, SDL_AudioSpec::channels, DATA, Chunk::data, done, WaveFMT::encoding, FACT, FMT, SDL_AudioSpec::format, SDL_AudioSpec::freq, WaveFMT::frequency, IEEE_FLOAT_CODE, IMA_ADPCM_CODE, IMA_ADPCM_decode(), InitIMA_ADPCM(), InitMS_ADPCM(), JUNK, Chunk::length, LIST, Chunk::magic, MP3_CODE, MS_ADPCM_CODE, MS_ADPCM_decode(), NULL, PCM_CODE, ReadChunk(), RIFF, RW_SEEK_CUR, SDL_AudioSpec::samples, SDL_AUDIO_BITSIZE, SDL_free(), SDL_memset, SDL_ReadLE32, SDL_RWclose, SDL_RWseek, SDL_SetError, SDL_SwapLE16, SDL_SwapLE32, SDL_zero, and WAVE.

{
int was_error;
Chunk chunk;
int lenread;
int IEEE_float_encoded, MS_ADPCM_encoded, IMA_ADPCM_encoded;
int samplesize;
/* WAV magic header */
Uint32 RIFFchunk;
Uint32 wavelen = 0;
Uint32 WAVEmagic;
Uint32 headerDiff = 0;
/* FMT chunk */
WaveFMT *format = NULL;
SDL_zero(chunk);
/* Make sure we are passed a valid data source */
was_error = 0;
if (src == NULL) {
was_error = 1;
goto done;
}
/* Check the magic header */
RIFFchunk = SDL_ReadLE32(src);
wavelen = SDL_ReadLE32(src);
if (wavelen == WAVE) { /* The RIFFchunk has already been read */
WAVEmagic = wavelen;
wavelen = RIFFchunk;
RIFFchunk = RIFF;
} else {
WAVEmagic = SDL_ReadLE32(src);
}
if ((RIFFchunk != RIFF) || (WAVEmagic != WAVE)) {
SDL_SetError("Unrecognized file type (not WAVE)");
was_error = 1;
goto done;
}
headerDiff += sizeof(Uint32); /* for WAVE */
/* Read the audio data format chunk */
chunk.data = NULL;
do {
SDL_free(chunk.data);
chunk.data = NULL;
lenread = ReadChunk(src, &chunk);
if (lenread < 0) {
was_error = 1;
goto done;
}
/* 2 Uint32's for chunk header+len, plus the lenread */
headerDiff += lenread + 2 * sizeof(Uint32);
} while ((chunk.magic == FACT) || (chunk.magic == LIST) || (chunk.magic == BEXT) || (chunk.magic == JUNK));
/* Decode the audio data format */
format = (WaveFMT *) chunk.data;
if (chunk.magic != FMT) {
SDL_SetError("Complex WAVE files not supported");
was_error = 1;
goto done;
}
IEEE_float_encoded = MS_ADPCM_encoded = IMA_ADPCM_encoded = 0;
switch (SDL_SwapLE16(format->encoding)) {
case PCM_CODE:
/* We can understand this */
break;
case IEEE_FLOAT_CODE:
IEEE_float_encoded = 1;
/* We can understand this */
break;
case MS_ADPCM_CODE:
/* Try to understand this */
if (InitMS_ADPCM(format) < 0) {
was_error = 1;
goto done;
}
MS_ADPCM_encoded = 1;
break;
case IMA_ADPCM_CODE:
/* Try to understand this */
if (InitIMA_ADPCM(format) < 0) {
was_error = 1;
goto done;
}
IMA_ADPCM_encoded = 1;
break;
case MP3_CODE:
SDL_SetError("MPEG Layer 3 data not supported");
was_error = 1;
goto done;
default:
SDL_SetError("Unknown WAVE data format: 0x%.4x",
SDL_SwapLE16(format->encoding));
was_error = 1;
goto done;
}
SDL_memset(spec, 0, (sizeof *spec));
spec->freq = SDL_SwapLE32(format->frequency);
if (IEEE_float_encoded) {
if ((SDL_SwapLE16(format->bitspersample)) != 32) {
was_error = 1;
} else {
spec->format = AUDIO_F32;
}
} else {
switch (SDL_SwapLE16(format->bitspersample)) {
case 4:
if (MS_ADPCM_encoded || IMA_ADPCM_encoded) {
spec->format = AUDIO_S16;
} else {
was_error = 1;
}
break;
case 8:
spec->format = AUDIO_U8;
break;
case 16:
spec->format = AUDIO_S16;
break;
case 32:
spec->format = AUDIO_S32;
break;
default:
was_error = 1;
break;
}
}
if (was_error) {
SDL_SetError("Unknown %d-bit PCM data format",
SDL_SwapLE16(format->bitspersample));
goto done;
}
spec->channels = (Uint8) SDL_SwapLE16(format->channels);
spec->samples = 4096; /* Good default buffer size */
/* Read the audio data chunk */
*audio_buf = NULL;
do {
SDL_free(*audio_buf);
*audio_buf = NULL;
lenread = ReadChunk(src, &chunk);
if (lenread < 0) {
was_error = 1;
goto done;
}
*audio_len = lenread;
*audio_buf = chunk.data;
if (chunk.magic != DATA)
headerDiff += lenread + 2 * sizeof(Uint32);
} while (chunk.magic != DATA);
headerDiff += 2 * sizeof(Uint32); /* for the data chunk and len */
if (MS_ADPCM_encoded) {
if (MS_ADPCM_decode(audio_buf, audio_len) < 0) {
was_error = 1;
goto done;
}
}
if (IMA_ADPCM_encoded) {
if (IMA_ADPCM_decode(audio_buf, audio_len) < 0) {
was_error = 1;
goto done;
}
}
/* Don't return a buffer that isn't a multiple of samplesize */
samplesize = ((SDL_AUDIO_BITSIZE(spec->format)) / 8) * spec->channels;
*audio_len &= ~(samplesize - 1);
done:
SDL_free(format);
if (src) {
if (freesrc) {
SDL_RWclose(src);
} else {
/* seek to the end of the file (given by the RIFF chunk) */
SDL_RWseek(src, wavelen - chunk.length - headerDiff, RW_SEEK_CUR);
}
}
if (was_error) {
spec = NULL;
}
return (spec);
}
InitIMA_ADPCM
static int InitIMA_ADPCM(WaveFMT *format)
Definition: SDL_wave.c:232
format
GLint GLint GLsizei GLsizei GLsizei GLint GLenum format
Definition: SDL_opengl.h:1565
PCM_CODE
#define PCM_CODE
Definition: SDL_wave.h:36
RIFF
#define RIFF
Definition: SDL_wave.h:28
LIST
#define LIST
Definition: SDL_wave.h:31
Uint32
uint32_t Uint32
An unsigned 32-bit integer type.
Definition: SDL_stdinc.h:155
WaveFMT
Definition: SDL_wave.h:45
MP3_CODE
#define MP3_CODE
Definition: SDL_wave.h:40
Chunk
Definition: SDL_wave.h:60
SDL_ReadLE32
#define SDL_ReadLE32
Definition: SDL_dynapi_overrides.h:365
Chunk::length
Uint32 length
Definition: SDL_wave.h:63
SDL_AudioSpec::samples
Uint16 samples
Definition: SDL_audio.h:174
WaveFMT::encoding
Uint16 encoding
Definition: SDL_wave.h:51
MS_ADPCM_decode
static int MS_ADPCM_decode(Uint8 **audio_buf, Uint32 *audio_len)
Definition: SDL_wave.c:119
WaveFMT::channels
Uint16 channels
Definition: SDL_wave.h:52
FMT
#define FMT
Definition: SDL_wave.h:34
SDL_RWseek
#define SDL_RWseek(ctx, offset, whence)
Definition: SDL_rwops.h:185
AUDIO_U8
#define AUDIO_U8
Definition: SDL_audio.h:89
SDL_AudioSpec::freq
int freq
Definition: SDL_audio.h:170
DATA
#define DATA
Definition: SDL_wave.h:35
FACT
#define FACT
Definition: SDL_wave.h:30
SDL_AudioSpec::channels
Uint8 channels
Definition: SDL_audio.h:172
IMA_ADPCM_decode
static int IMA_ADPCM_decode(Uint8 **audio_buf, Uint32 *audio_len)
Definition: SDL_wave.c:338
Uint8
uint8_t Uint8
An unsigned 8-bit integer type.
Definition: SDL_stdinc.h:139
SDL_free
void SDL_free(void *mem)
SDL_AUDIO_BITSIZE
#define SDL_AUDIO_BITSIZE(x)
Definition: SDL_audio.h:75
SDL_SwapLE32
#define SDL_SwapLE32(X)
Definition: SDL_endian.h:212
done
int done
Definition: checkkeys.c:28
AUDIO_S32
#define AUDIO_S32
Definition: SDL_audio.h:105
WAVE
#define WAVE
Definition: SDL_wave.h:29
JUNK
#define JUNK
Definition: SDL_wave.h:33
SDL_zero
#define SDL_zero(x)
Definition: SDL_stdinc.h:355
Chunk::data
Uint8 * data
Definition: SDL_wave.h:64
NULL
#define NULL
Definition: begin_code.h:143
IEEE_FLOAT_CODE
#define IEEE_FLOAT_CODE
Definition: SDL_wave.h:38
SDL_RWclose
#define SDL_RWclose(ctx)
Definition: SDL_rwops.h:189
IMA_ADPCM_CODE
#define IMA_ADPCM_CODE
Definition: SDL_wave.h:39
SDL_SetError
#define SDL_SetError
Definition: SDL_dynapi_overrides.h:36
SDL_AudioSpec::format
SDL_AudioFormat format
Definition: SDL_audio.h:171
InitMS_ADPCM
static int InitMS_ADPCM(WaveFMT *format)
Definition: SDL_wave.c:49
Chunk::magic
Uint32 magic
Definition: SDL_wave.h:62
AUDIO_S16
#define AUDIO_S16
Definition: SDL_audio.h:96
WaveFMT::frequency
Uint32 frequency
Definition: SDL_wave.h:53
RW_SEEK_CUR
#define RW_SEEK_CUR
Definition: SDL_rwops.h:175
WaveFMT::bitspersample
Uint16 bitspersample
Definition: SDL_wave.h:56
AUDIO_F32
#define AUDIO_F32
Definition: SDL_audio.h:114
SDL_SwapLE16
#define SDL_SwapLE16(X)
Definition: SDL_endian.h:211
BEXT
#define BEXT
Definition: SDL_wave.h:32
SDL_memset
#define SDL_memset
Definition: SDL_dynapi_overrides.h:392
ReadChunk
static int ReadChunk(SDL_RWops *src, Chunk *chunk)
Definition: SDL_wave.c:608
MS_ADPCM_CODE
#define MS_ADPCM_CODE
Definition: SDL_wave.h:37

void SDL_LockAudio | ( | void |  | ) |

Definition at line 1307 of file SDL_audio.c.

References SDL_LockAudioDevice().

{
SDL_LockAudioDevice(1);
}
SDL_LockAudioDevice
void SDL_LockAudioDevice(SDL_AudioDeviceID devid)
Definition: SDL_audio.c:1297

void SDL_LockAudioDevice | ( | SDL_AudioDeviceID | dev | ) |

Definition at line 1297 of file SDL_audio.c.

References get_audio_device(), SDL_AudioDriver::impl, and SDL_AudioDriverImpl::LockDevice.

Referenced by SDL_LockAudio().

{
/* Obtain a lock on the mixing buffers */
SDL_AudioDevice *device = get_audio_device(devid);
if (device) {
current_audio.impl.LockDevice(device);
}
}
current_audio
static SDL_AudioDriver current_audio
Definition: SDL_audio.c:33
SDL_AudioDriverImpl::LockDevice
void(* LockDevice)(_THIS)
Definition: SDL_sysaudio.h:80
SDL_AudioDriver::impl
SDL_AudioDriverImpl impl
Definition: SDL_sysaudio.h:120
SDL_AudioDevice
Definition: SDL_sysaudio.h:143
get_audio_device
static SDL_AudioDevice * get_audio_device(SDL_AudioDeviceID id)
Definition: SDL_audio.c:150

void SDL_MixAudio | ( | Uint8 * | dst,
|  | const Uint8 * | src,
|  | Uint32 | len,
|  | int | volume
| ) |  |

This takes two audio buffers of the playing audio format and mixes them, performing addition, volume adjustment, and overflow clipping. The volume ranges from 0 - 128, and should be set to SDL_MIX_MAXVOLUME for full audio volume. Note this does not change hardware volume. This is provided for convenience – you can mix your own audio data.

Definition at line 1440 of file SDL_audio.c.

References SDL_AudioDevice::convert, SDL_AudioSpec::format, get_audio_device(), SDL_AudioCVT::needed, NULL, SDL_MixAudioFormat, SDL_AudioDevice::spec, and SDL_AudioCVT::src_format.

{
/* Mix the user-level audio format */
SDL_AudioDevice *device = get_audio_device(1);
if (device != NULL) {
SDL_AudioFormat format;
if (device->convert.needed) {
format = device->convert.src_format;
} else {
format = device->spec.format;
}
SDL_MixAudioFormat(dst, src, format, len, volume);
}
}
dst
GLenum GLenum dst
Definition: SDL_opengl_glext.h:1737
format
GLint GLint GLsizei GLsizei GLsizei GLint GLenum format
Definition: SDL_opengl.h:1565
SDL_MixAudioFormat
#define SDL_MixAudioFormat
Definition: SDL_dynapi_overrides.h:97
SDL_AudioDevice::spec
SDL_AudioSpec spec
Definition: SDL_sysaudio.h:150
SDL_AudioFormat
Uint16 SDL_AudioFormat
Audio format flags.
Definition: SDL_audio.h:64
len
GLenum GLsizei len
Definition: SDL_opengl_glext.h:2926
SDL_AudioCVT::needed
int needed
Definition: SDL_audio.h:202
SDL_AudioCVT::src_format
SDL_AudioFormat src_format
Definition: SDL_audio.h:203
NULL
#define NULL
Definition: begin_code.h:143
SDL_AudioDevice
Definition: SDL_sysaudio.h:143
SDL_AudioSpec::format
SDL_AudioFormat format
Definition: SDL_audio.h:171
SDL_AudioDevice::convert
SDL_AudioCVT convert
Definition: SDL_sysaudio.h:153
src
GLenum src
Definition: SDL_opengl_glext.h:1737
get_audio_device
static SDL_AudioDevice * get_audio_device(SDL_AudioDeviceID id)
Definition: SDL_audio.c:150

void SDL_MixAudioFormat | ( | Uint8 * | dst,
|  | const Uint8 * | src,
|  | SDL_AudioFormat | format,
|  | Uint32 | len,
|  | int | volume
| ) |  |

This works like SDL_MixAudio(), but you specify the audio format instead of using the format of audio device 1. Thus it can be used when no audio device is open at all.

Definition at line 90 of file SDL_mixer.c.

References ADJUST_VOLUME, ADJUST_VOLUME_U8, AUDIO_F32LSB, AUDIO_F32MSB, AUDIO_S16LSB, AUDIO_S16MSB, AUDIO_S32LSB, AUDIO_S32MSB, AUDIO_S8, AUDIO_U8, F, mix8, SDL_MIX_MAXVOLUME, SDL_SetError, SDL_SwapBE32, SDL_SwapFloatBE, SDL_SwapFloatLE, and SDL_SwapLE32.

{
if (volume == 0) {
return;
}
switch (format) {
case AUDIO_U8:
{
#if defined(__GNUC__) && defined(__M68000__) && !defined(__mcoldfire__) && defined(SDL_ASSEMBLY_ROUTINES)
SDL_MixAudio_m68k_U8((char *) dst, (char *) src,
(unsigned long) len, (long) volume,
(char *) mix8);
#else
Uint8 src_sample;
while (len--) {
src_sample = *src;
ADJUST_VOLUME_U8(src_sample, volume);
*dst = mix8[*dst + src_sample];
++dst;
++src;
}
#endif
}
break;
case AUDIO_S8:
{
Sint8 *dst8, *src8;
Sint8 src_sample;
int dst_sample;
const int max_audioval = ((1 << (8 - 1)) - 1);
const int min_audioval = -(1 << (8 - 1));
src8 = (Sint8 *) src;
dst8 = (Sint8 *) dst;
while (len--) {
src_sample = *src8;
ADJUST_VOLUME(src_sample, volume);
dst_sample = *dst8 + src_sample;
if (dst_sample > max_audioval) {
*dst8 = max_audioval;
} else if (dst_sample < min_audioval) {
*dst8 = min_audioval;
} else {
*dst8 = dst_sample;
}
++dst8;
++src8;
}
}
break;
case AUDIO_S16LSB:
{
Sint16 src1, src2;
int dst_sample;
const int max_audioval = ((1 << (16 - 1)) - 1);
const int min_audioval = -(1 << (16 - 1));
len /= 2;
while (len--) {
src1 = ((src[1]) << 8 | src[0]);
ADJUST_VOLUME(src1, volume);
src2 = ((dst[1]) << 8 | dst[0]);
src += 2;
dst_sample = src1 + src2;
if (dst_sample > max_audioval) {
dst_sample = max_audioval;
} else if (dst_sample < min_audioval) {
dst_sample = min_audioval;
}
dst[0] = dst_sample & 0xFF;
dst_sample >>= 8;
dst[1] = dst_sample & 0xFF;
dst += 2;
}
}
break;
case AUDIO_S16MSB:
{
#if defined(__GNUC__) && defined(__M68000__) && !defined(__mcoldfire__) && defined(SDL_ASSEMBLY_ROUTINES)
SDL_MixAudio_m68k_S16MSB((short *) dst, (short *) src,
(unsigned long) len, (long) volume);
#else
Sint16 src1, src2;
int dst_sample;
const int max_audioval = ((1 << (16 - 1)) - 1);
const int min_audioval = -(1 << (16 - 1));
len /= 2;
while (len--) {
src1 = ((src[0]) << 8 | src[1]);
ADJUST_VOLUME(src1, volume);
src2 = ((dst[0]) << 8 | dst[1]);
src += 2;
dst_sample = src1 + src2;
if (dst_sample > max_audioval) {
dst_sample = max_audioval;
} else if (dst_sample < min_audioval) {
dst_sample = min_audioval;
}
dst[1] = dst_sample & 0xFF;
dst_sample >>= 8;
dst[0] = dst_sample & 0xFF;
dst += 2;
}
#endif
}
break;
case AUDIO_S32LSB:
{
const Uint32 *src32 = (Uint32 *) src;
Uint32 *dst32 = (Uint32 *) dst;
Sint64 src1, src2;
Sint64 dst_sample;
const Sint64 max_audioval = ((((Sint64) 1) << (32 - 1)) - 1);
const Sint64 min_audioval = -(((Sint64) 1) << (32 - 1));
len /= 4;
while (len--) {
src1 = (Sint64) ((Sint32) SDL_SwapLE32(*src32));
src32++;
ADJUST_VOLUME(src1, volume);
src2 = (Sint64) ((Sint32) SDL_SwapLE32(*dst32));
dst_sample = src1 + src2;
if (dst_sample > max_audioval) {
dst_sample = max_audioval;
} else if (dst_sample < min_audioval) {
dst_sample = min_audioval;
}
*(dst32++) = SDL_SwapLE32((Uint32) ((Sint32) dst_sample));
}
}
break;
case AUDIO_S32MSB:
{
const Uint32 *src32 = (Uint32 *) src;
Uint32 *dst32 = (Uint32 *) dst;
Sint64 src1, src2;
Sint64 dst_sample;
const Sint64 max_audioval = ((((Sint64) 1) << (32 - 1)) - 1);
const Sint64 min_audioval = -(((Sint64) 1) << (32 - 1));
len /= 4;
while (len--) {
src1 = (Sint64) ((Sint32) SDL_SwapBE32(*src32));
src32++;
ADJUST_VOLUME(src1, volume);
src2 = (Sint64) ((Sint32) SDL_SwapBE32(*dst32));
dst_sample = src1 + src2;
if (dst_sample > max_audioval) {
dst_sample = max_audioval;
} else if (dst_sample < min_audioval) {
dst_sample = min_audioval;
}
*(dst32++) = SDL_SwapBE32((Uint32) ((Sint32) dst_sample));
}
}
break;
case AUDIO_F32LSB:
{
const float fmaxvolume = 1.0f / ((float) SDL_MIX_MAXVOLUME);
const float fvolume = (float) volume;
const float *src32 = (float *) src;
float *dst32 = (float *) dst;
float src1, src2;
double dst_sample;
/* !!! FIXME: are these right? */
const double max_audioval = 3.402823466e+38F;
const double min_audioval = -3.402823466e+38F;
len /= 4;
while (len--) {
src1 = ((SDL_SwapFloatLE(*src32) * fvolume) * fmaxvolume);
src2 = SDL_SwapFloatLE(*dst32);
src32++;
dst_sample = ((double) src1) + ((double) src2);
if (dst_sample > max_audioval) {
dst_sample = max_audioval;
} else if (dst_sample < min_audioval) {
dst_sample = min_audioval;
}
*(dst32++) = SDL_SwapFloatLE((float) dst_sample);
}
}
break;
case AUDIO_F32MSB:
{
const float fmaxvolume = 1.0f / ((float) SDL_MIX_MAXVOLUME);
const float fvolume = (float) volume;
const float *src32 = (float *) src;
float *dst32 = (float *) dst;
float src1, src2;
double dst_sample;
/* !!! FIXME: are these right? */
const double max_audioval = 3.402823466e+38F;
const double min_audioval = -3.402823466e+38F;
len /= 4;
while (len--) {
src1 = ((SDL_SwapFloatBE(*src32) * fvolume) * fmaxvolume);
src2 = SDL_SwapFloatBE(*dst32);
src32++;
dst_sample = ((double) src1) + ((double) src2);
if (dst_sample > max_audioval) {
dst_sample = max_audioval;
} else if (dst_sample < min_audioval) {
dst_sample = min_audioval;
}
*(dst32++) = SDL_SwapFloatBE((float) dst_sample);
}
}
break;
default: /* If this happens... FIXME! */
SDL_SetError("SDL_MixAudio(): unknown audio format");
return;
}
}
SDL_MIX_MAXVOLUME
#define SDL_MIX_MAXVOLUME
Definition: SDL_audio.h:461
dst
GLenum GLenum dst
Definition: SDL_opengl_glext.h:1737
ADJUST_VOLUME
#define ADJUST_VOLUME(s, v)
Definition: SDL_mixer.c:85
format
GLint GLint GLsizei GLsizei GLsizei GLint GLenum format
Definition: SDL_opengl.h:1565
SDL_SwapFloatBE
#define SDL_SwapFloatBE(X)
Definition: SDL_endian.h:218
AUDIO_S32MSB
#define AUDIO_S32MSB
Definition: SDL_audio.h:104
Uint32
uint32_t Uint32
An unsigned 32-bit integer type.
Definition: SDL_stdinc.h:155
SDL_SwapFloatLE
#define SDL_SwapFloatLE(X)
Definition: SDL_endian.h:214
len
GLenum GLsizei len
Definition: SDL_opengl_glext.h:2926
SDL_SwapBE32
#define SDL_SwapBE32(X)
Definition: SDL_endian.h:216
AUDIO_F32MSB
#define AUDIO_F32MSB
Definition: SDL_audio.h:113
mix8
static const Uint8 mix8[]
Definition: SDL_mixer.c:34
AUDIO_U8
#define AUDIO_U8
Definition: SDL_audio.h:89
Sint8
int8_t Sint8
A signed 8-bit integer type.
Definition: SDL_stdinc.h:135
Uint8
uint8_t Uint8
An unsigned 8-bit integer type.
Definition: SDL_stdinc.h:139
ADJUST_VOLUME_U8
#define ADJUST_VOLUME_U8(s, v)
Definition: SDL_mixer.c:86
SDL_SwapLE32
#define SDL_SwapLE32(X)
Definition: SDL_endian.h:212
AUDIO_F32LSB
#define AUDIO_F32LSB
Definition: SDL_audio.h:112
AUDIO_S32LSB
#define AUDIO_S32LSB
Definition: SDL_audio.h:103
Sint32
int32_t Sint32
A signed 32-bit integer type.
Definition: SDL_stdinc.h:151
SDL_SetError
#define SDL_SetError
Definition: SDL_dynapi_overrides.h:36
AUDIO_S16MSB
#define AUDIO_S16MSB
Definition: SDL_audio.h:94
AUDIO_S16LSB
#define AUDIO_S16LSB
Definition: SDL_audio.h:92
F
#define F(x, y, z)
Definition: SDL_test_md5.c:73
Sint64
int64_t Sint64
A signed 64-bit integer type.
Definition: SDL_stdinc.h:160
AUDIO_S8
#define AUDIO_S8
Definition: SDL_audio.h:90
src
GLenum src
Definition: SDL_opengl_glext.h:1737
Sint16
int16_t Sint16
A signed 16-bit integer type.
Definition: SDL_stdinc.h:143

int SDL_OpenAudio | ( | SDL_AudioSpec * | desired,
|  | SDL_AudioSpec * | obtained
| ) |  |

This function opens the audio device with the desired parameters, and returns 0 if successful, placing the actual hardware parameters in the structure pointed to by `obtained`. If `obtained` is NULL, the audio data passed to the callback function will be guaranteed to be in the requested format, and will be automatically converted to the hardware audio format if necessary. This function returns -1 if it failed to open the audio device, or couldn't set up the audio thread.

When filling in the desired audio spec structure,

- `desired->freq` should be the desired audio frequency in samples-per- second.
- `desired->format` should be the desired audio format.
- `desired->samples` is the desired size of the audio buffer, in samples. This number should be a power of two, and may be adjusted by the audio driver to a value more suitable for the hardware. Good values seem to range between 512 and 8096 inclusive, depending on the application and CPU speed. Smaller values yield faster response time, but can lead to underflow if the application is doing heavy processing and cannot fill the audio buffer in time. A stereo sample consists of both right and left channels in LR ordering. Note that the number of samples is directly related to time by the following formula:
  ms = (samples*1000)/freq
- `desired->size` is the size in bytes of the audio buffer, and is calculated by SDL_OpenAudio().
- `desired->silence` is the value used to set the buffer to silence, and is calculated by SDL_OpenAudio().
- `desired->callback` should be set to a function that will be called when the audio device is ready for more data. It is passed a pointer to the audio buffer, and the length in bytes of the audio buffer. This function usually runs in a separate thread, and so you should protect data structures that it accesses by calling SDL_LockAudio() and SDL_UnlockAudio() in your code. Alternately, you may pass a NULL pointer here, and call SDL_QueueAudio() with some frequency, to queue more audio samples to be played.
- `desired->userdata` is passed as the first parameter to your callback function. If you passed a NULL callback, this value is ignored.

The audio device starts out playing silence when it's opened, and should be enabled for playing by calling `SDL_PauseAudio(0)` when you are ready for your audio callback function to be called. Since the audio driver may modify the requested size of the audio buffer, you should allocate any local mixing buffers after you open the audio device.

Definition at line 1219 of file SDL_audio.c.

References NULL, open_audio_device(), SDL_assert, SDL_AUDIO_ALLOW_ANY_CHANGE, SDL_INIT_AUDIO, SDL_InitSubSystem, SDL_SetError, and SDL_WasInit.

{
SDL_AudioDeviceID id = 0;
/* Start up the audio driver, if necessary. This is legacy behaviour! */
if (!SDL_WasInit(SDL_INIT_AUDIO)) {
if (SDL_InitSubSystem(SDL_INIT_AUDIO) < 0) {
return -1;
}
}
/* SDL_OpenAudio() is legacy and can only act on Device ID #1. */
if (open_devices[0] != NULL) {
SDL_SetError("Audio device is already opened");
return -1;
}
if (obtained) {
id = open_audio_device(NULL, 0, desired, obtained,
SDL_AUDIO_ALLOW_ANY_CHANGE, 1);
} else {
id = open_audio_device(NULL, 0, desired, NULL, 0, 1);
}
SDL_assert((id == 0) || (id == 1));
return (id == 0) ? -1 : 0;
}
open_devices
static SDL_AudioDevice * open_devices[16]
Definition: SDL_audio.c:34
SDL_InitSubSystem
#define SDL_InitSubSystem
Definition: SDL_dynapi_overrides.h:61
SDL_AUDIO_ALLOW_ANY_CHANGE
#define SDL_AUDIO_ALLOW_ANY_CHANGE
Definition: SDL_audio.h:143
SDL_assert
#define SDL_assert(condition)
Definition: SDL_assert.h:167
NULL
#define NULL
Definition: begin_code.h:143
SDL_SetError
#define SDL_SetError
Definition: SDL_dynapi_overrides.h:36
open_audio_device
static SDL_AudioDeviceID open_audio_device(const char *devname, int iscapture, const SDL_AudioSpec *desired, SDL_AudioSpec *obtained, int allowed_changes, int min_id)
Definition: SDL_audio.c:962
SDL_INIT_AUDIO
#define SDL_INIT_AUDIO
Definition: SDL.h:76
SDL_AudioDeviceID
Uint32 SDL_AudioDeviceID
Definition: SDL_audio.h:303
SDL_WasInit
#define SDL_WasInit
Definition: SDL_dynapi_overrides.h:63

SDL_AudioDeviceID SDL_OpenAudioDevice | ( | const char * | device,
|  | int | iscapture,
|  | const SDL_AudioSpec * | desired,
|  | SDL_AudioSpec * | obtained,
|  | int | allowed_changes
| ) |  |

Open a specific audio device. Passing in a device name of NULL requests the most reasonable default (and is equivalent to calling SDL_OpenAudio()).

The device name is a UTF-8 string reported by SDL_GetAudioDeviceName(), but some drivers allow arbitrary and driver-specific strings, such as a hostname/IP address for a remote audio server, or a filename in the diskaudio driver.

Returns
  0 on error, a valid device ID that is >= 2 on success.

SDL_OpenAudio(), unlike this function, always acts on device ID 1.

Definition at line 1248 of file SDL_audio.c.

References open_audio_device().

{
return open_audio_device(device, iscapture, desired, obtained,
allowed_changes, 2);
}
open_audio_device
static SDL_AudioDeviceID open_audio_device(const char *devname, int iscapture, const SDL_AudioSpec *desired, SDL_AudioSpec *obtained, int allowed_changes, int min_id)
Definition: SDL_audio.c:962

void SDL_PauseAudio | ( | int | pause_on | ) |

Definition at line 1290 of file SDL_audio.c.

References SDL_PauseAudioDevice().

{
SDL_PauseAudioDevice(1, pause_on);
}
SDL_PauseAudioDevice
void SDL_PauseAudioDevice(SDL_AudioDeviceID devid, int pause_on)
Definition: SDL_audio.c:1279

void SDL_PauseAudioDevice | ( | SDL_AudioDeviceID | dev,
|  | int | pause_on
| ) |  |

Definition at line 1279 of file SDL_audio.c.

References get_audio_device(), SDL_AudioDriver::impl, SDL_AudioDriverImpl::LockDevice, SDL_AudioDevice::paused, and SDL_AudioDriverImpl::UnlockDevice.

Referenced by SDL_PauseAudio().

{
SDL_AudioDevice *device = get_audio_device(devid);
if (device) {
current_audio.impl.LockDevice(device);
device->paused = pause_on;
current_audio.impl.UnlockDevice(device);
}
}
current_audio
static SDL_AudioDriver current_audio
Definition: SDL_audio.c:33
SDL_AudioDriverImpl::UnlockDevice
void(* UnlockDevice)(_THIS)
Definition: SDL_sysaudio.h:81
SDL_AudioDriverImpl::LockDevice
void(* LockDevice)(_THIS)
Definition: SDL_sysaudio.h:80
SDL_AudioDriver::impl
SDL_AudioDriverImpl impl
Definition: SDL_sysaudio.h:120
SDL_AudioDevice
Definition: SDL_sysaudio.h:143
SDL_AudioDevice::paused
int paused
Definition: SDL_sysaudio.h:164
get_audio_device
static SDL_AudioDevice * get_audio_device(SDL_AudioDeviceID id)
Definition: SDL_audio.c:150

int SDL_QueueAudio | ( | SDL_AudioDeviceID | dev,
|  | const void * | data,
|  | Uint32 | len
| ) |  |

Queue more audio on non-callback devices.

SDL offers two ways to feed audio to the device: you can either supply a callback that SDL triggers with some frequency to obtain more audio (pull method), or you can supply no callback, and then SDL will expect you to supply data at regular intervals (push method) with this function.

There are no limits on the amount of data you can queue, short of exhaustion of address space. Queued data will drain to the device as necessary without further intervention from you. If the device needs audio but there is not enough queued, it will play silence to make up the difference. This means you will have skips in your audio playback if you aren't routinely queueing sufficient data.

This function copies the supplied data, so you are safe to free it when the function returns. This function is thread-safe, but queueing to the same device from two threads at once does not promise which buffer will be queued first.

You may not queue audio on a device that is using an application-supplied callback; doing so returns an error. You have to use the audio callback or queue audio with this function, but not both.

You should not call SDL_LockAudio() on the device before queueing; SDL handles locking internally for this function.

Parameters

  dev | The device ID to which we will queue audio.
  data | The data to queue to the device for later playback.
  len | The number of bytes (not samples!) to which (data) points.

Returns
  zero on success, -1 on error.

See also
  SDL_GetQueuedAudioSize
  SDL_ClearQueuedAudio

Definition at line 475 of file SDL_audio.c.

References SDL_AudioDevice::buffer_queue_head, SDL_AudioDevice::buffer_queue_pool, SDL_AudioDevice::buffer_queue_tail, SDL_AudioSpec::callback, SDL_AudioBufferQueue::data, SDL_AudioBufferQueue::datalen, free_audio_queue(), get_audio_device(), SDL_AudioDriver::impl, SDL_AudioDriverImpl::LockDevice, SDL_AudioBufferQueue::next, NULL, SDL_AudioDevice::queued_bytes, SDL_assert, SDL_AUDIOBUFFERQUEUE_PACKETLEN, SDL_BufferQueueDrainCallback(), SDL_malloc, SDL_memcpy, SDL_min, SDL_OutOfMemory, SDL_SetError, SDL_AudioDevice::spec, SDL_AudioBufferQueue::startpos, and SDL_AudioDriverImpl::UnlockDevice.

{
SDL_AudioDevice *device = get_audio_device(devid);
const Uint8 *data = (const Uint8 *) _data;
SDL_AudioBufferQueue *orighead;
SDL_AudioBufferQueue *origtail;
Uint32 origlen;
Uint32 datalen;
if (!device) {
return -1; /* get_audio_device() will have set the error state */
}
if (device->spec.callback != SDL_BufferQueueDrainCallback) {
return SDL_SetError("Audio device has a callback, queueing not allowed");
}
current_audio.impl.LockDevice(device);
orighead = device->buffer_queue_head;
origtail = device->buffer_queue_tail;
origlen = origtail ? origtail->datalen : 0;
while (len > 0) {
SDL_AudioBufferQueue *packet = device->buffer_queue_tail;
SDL_assert(!packet || (packet->datalen <= SDL_AUDIOBUFFERQUEUE_PACKETLEN));
if (!packet || (packet->datalen >= SDL_AUDIOBUFFERQUEUE_PACKETLEN)) {
/* tail packet missing or completely full; we need a new packet. */
packet = device->buffer_queue_pool;
if (packet != NULL) {
/* we have one available in the pool. */
device->buffer_queue_pool = packet->next;
} else {
/* Have to allocate a new one! */
packet = (SDL_AudioBufferQueue *) SDL_malloc(sizeof (SDL_AudioBufferQueue));
if (packet == NULL) {
/* uhoh, reset so we've queued nothing new, free what we can. */
if (!origtail) {
packet = device->buffer_queue_head; /* whole queue. */
} else {
packet = origtail->next; /* what we added to existing queue. */
origtail->next = NULL;
origtail->datalen = origlen;
}
device->buffer_queue_head = orighead;
device->buffer_queue_tail = origtail;
device->buffer_queue_pool = NULL;
current_audio.impl.UnlockDevice(device);
free_audio_queue(packet); /* give back what we can. */
return SDL_OutOfMemory();
}
}
packet->datalen = 0;
packet->startpos = 0;
packet->next = NULL;
SDL_assert((device->buffer_queue_head != NULL) == (device->queued_bytes != 0));
if (device->buffer_queue_tail == NULL) {
device->buffer_queue_head = packet;
} else {
device->buffer_queue_tail->next = packet;
}
device->buffer_queue_tail = packet;
}
datalen = SDL_min(len, SDL_AUDIOBUFFERQUEUE_PACKETLEN - packet->datalen);
SDL_memcpy(packet->data + packet->datalen, data, datalen);
data += datalen;
len -= datalen;
packet->datalen += datalen;
device->queued_bytes += datalen;
}
current_audio.impl.UnlockDevice(device);
return 0;
}
SDL_AudioBufferQueue::datalen
Uint32 datalen
Definition: SDL_sysaudio.h:64
SDL_min
#define SDL_min(x, y)
Definition: SDL_stdinc.h:345
Uint32
uint32_t Uint32
An unsigned 32-bit integer type.
Definition: SDL_stdinc.h:155
data
GLint GLenum GLsizei GLsizei GLsizei GLint GLsizei const GLvoid * data
Definition: SDL_opengl.h:1967
SDL_AudioDevice::buffer_queue_pool
SDL_AudioBufferQueue * buffer_queue_pool
Definition: SDL_sysaudio.h:180
SDL_AudioDevice::spec
SDL_AudioSpec spec
Definition: SDL_sysaudio.h:150
current_audio
static SDL_AudioDriver current_audio
Definition: SDL_audio.c:33
SDL_AudioDriverImpl::UnlockDevice
void(* UnlockDevice)(_THIS)
Definition: SDL_sysaudio.h:81
len
GLenum GLsizei len
Definition: SDL_opengl_glext.h:2926
SDL_AudioDevice::queued_bytes
Uint32 queued_bytes
Definition: SDL_sysaudio.h:181
SDL_AudioDevice::buffer_queue_head
SDL_AudioBufferQueue * buffer_queue_head
Definition: SDL_sysaudio.h:178
SDL_AudioDevice::buffer_queue_tail
SDL_AudioBufferQueue * buffer_queue_tail
Definition: SDL_sysaudio.h:179
SDL_memcpy
#define SDL_memcpy
Definition: SDL_dynapi_overrides.h:393
SDL_AudioBufferQueue
Definition: SDL_sysaudio.h:61
SDL_AudioBufferQueue::next
struct SDL_AudioBufferQueue * next
Definition: SDL_sysaudio.h:66
Uint8
uint8_t Uint8
An unsigned 8-bit integer type.
Definition: SDL_stdinc.h:139
SDL_AudioSpec::callback
SDL_AudioCallback callback
Definition: SDL_audio.h:177
SDL_AudioDriverImpl::LockDevice
void(* LockDevice)(_THIS)
Definition: SDL_sysaudio.h:80
SDL_assert
#define SDL_assert(condition)
Definition: SDL_assert.h:167
NULL
#define NULL
Definition: begin_code.h:143
SDL_OutOfMemory
#define SDL_OutOfMemory()
Definition: SDL_error.h:52
free_audio_queue
static void free_audio_queue(SDL_AudioBufferQueue *buffer)
Definition: SDL_audio.c:423
SDL_SetError
#define SDL_SetError
Definition: SDL_dynapi_overrides.h:36
SDL_AudioDriver::impl
SDL_AudioDriverImpl impl
Definition: SDL_sysaudio.h:120
SDL_AudioDevice
Definition: SDL_sysaudio.h:143
SDL_AudioBufferQueue::startpos
Uint32 startpos
Definition: SDL_sysaudio.h:65
SDL_AudioBufferQueue::data
Uint8 data[SDL_AUDIOBUFFERQUEUE_PACKETLEN]
Definition: SDL_sysaudio.h:63
SDL_malloc
#define SDL_malloc
Definition: SDL_dynapi_overrides.h:380
SDL_AUDIOBUFFERQUEUE_PACKETLEN
#define SDL_AUDIOBUFFERQUEUE_PACKETLEN
Definition: SDL_sysaudio.h:58
SDL_BufferQueueDrainCallback
static void SDL_BufferQueueDrainCallback(void *userdata, Uint8 *stream, int _len)
Definition: SDL_audio.c:433
get_audio_device
static SDL_AudioDevice * get_audio_device(SDL_AudioDeviceID id)
Definition: SDL_audio.c:150

void SDL_UnlockAudio | ( | void |  | ) |

Definition at line 1323 of file SDL_audio.c.

References SDL_UnlockAudioDevice().

{
SDL_UnlockAudioDevice(1);
}
SDL_UnlockAudioDevice
void SDL_UnlockAudioDevice(SDL_AudioDeviceID devid)
Definition: SDL_audio.c:1313

void SDL_UnlockAudioDevice | ( | SDL_AudioDeviceID | dev | ) |

Definition at line 1313 of file SDL_audio.c.

References get_audio_device(), SDL_AudioDriver::impl, and SDL_AudioDriverImpl::UnlockDevice.

Referenced by SDL_UnlockAudio().

{
/* Obtain a lock on the mixing buffers */
SDL_AudioDevice *device = get_audio_device(devid);
if (device) {
current_audio.impl.UnlockDevice(device);
}
}
current_audio
static SDL_AudioDriver current_audio
Definition: SDL_audio.c:33
SDL_AudioDriverImpl::UnlockDevice
void(* UnlockDevice)(_THIS)
Definition: SDL_sysaudio.h:81
SDL_AudioDriver::impl
SDL_AudioDriverImpl impl
Definition: SDL_sysaudio.h:120
SDL_AudioDevice
Definition: SDL_sysaudio.h:143
get_audio_device
static SDL_AudioDevice * get_audio_device(SDL_AudioDeviceID id)
Definition: SDL_audio.c:150