/*

     SDL - Simple DirectMedia Layer

     Copyright (C) 1997-2009 Sam Lantinga

     This library is free software; you can redistribute it and/or

     modify it under the terms of the GNU Lesser General Public

     License as published by the Free Software Foundation; either

     version 2.1 of the License, or (at your option) any later version.

     This library is distributed in the hope that it will be useful,

     but WITHOUT ANY WARRANTY; without even the implied warranty of

     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

     Lesser General Public License for more details.

     You should have received a copy of the GNU Lesser General Public

     License along with this library; if not, write to the Free Software

     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

     Sam Lantinga

     slouken@libsdl.org

 */

 /**

  *  \file SDL_audio.h

  *  

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

  */

 #ifndef _SDL_audio_h

 #define _SDL_audio_h

 #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"

 /* Set up for C function definitions, even when using C++ */

 #ifdef __cplusplus

 /* *INDENT-OFF* */

 extern "C" {

 /* *INDENT-ON* */

 #endif

 /**

  *  \brief Audio format flags.

  *  

  *  These are what the 16 bits in SDL_AudioFormat currently mean...

  *  (Unspecified bits are always zero).

  *  

  *  \verbatim

     ++-----------------------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

     \endverbatim

  *  

  *  There are macros in SDL 1.3 and later to query these bits.

  */

 typedef Uint16 SDL_AudioFormat;

 /**

  *  \name 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))

 /** 

  *  \name Audio format flags

  *

  *  Defaults to LSB byte order.

  */

 /*@{*/

 #define AUDIO_U8	0x0008  /**< Unsigned 8-bit samples */

 #define AUDIO_S8	0x8008  /**< Signed 8-bit samples */

 #define AUDIO_U16LSB	0x0010  /**< Unsigned 16-bit samples */

 #define AUDIO_S16LSB	0x8010  /**< Signed 16-bit samples */

 #define AUDIO_U16MSB	0x1010  /**< As above, but big-endian byte order */

 #define AUDIO_S16MSB	0x9010  /**< As above, but big-endian byte order */

 #define AUDIO_U16	AUDIO_U16LSB

 #define AUDIO_S16	AUDIO_S16LSB

 /*@}*/

 /**

  *  \name int32 support

  *  

  *  New to SDL 1.3.

  */

 /*@{*/

 #define AUDIO_S32LSB	0x8020  /**< 32-bit integer samples */

 #define AUDIO_S32MSB	0x9020  /**< As above, but big-endian byte order */

 #define AUDIO_S32	AUDIO_S32LSB

 /*@}*/

 /**

  *  \name float32 support

  *  

  *  New to SDL 1.3.

  */

 /*@{*/

 #define AUDIO_F32LSB	0x8120  /**< 32-bit floating point samples */

 #define AUDIO_F32MSB	0x9120  /**< As above, but big-endian byte order */

 #define AUDIO_F32	AUDIO_F32LSB

 /*@}*/

 /**

  *  \name Native audio byte ordering

  */

 /*@{*/

 #if SDL_BYTEORDER == SDL_LIL_ENDIAN

 #define AUDIO_U16SYS	AUDIO_U16LSB

 #define AUDIO_S16SYS	AUDIO_S16LSB

 #define AUDIO_S32SYS	AUDIO_S32LSB

 #define AUDIO_F32SYS	AUDIO_F32LSB

 #else

 #define AUDIO_U16SYS	AUDIO_U16MSB

 #define AUDIO_S16SYS	AUDIO_S16MSB

 #define AUDIO_S32SYS	AUDIO_S32MSB

 #define AUDIO_F32SYS	AUDIO_F32MSB

 #endif

 /*@}*/

 /** 

  *  \name 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)

 /*@}*/

 /*@}*//*Audio flags*/

 /**

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

  *

  *  \param userdata An application-specific parameter saved in

  *                  the SDL_AudioSpec structure

  *  \param stream A pointer to the audio data buffer.

  *  \param 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.

  */

 typedef void (SDLCALL * SDL_AudioCallback) (void *userdata, Uint8 * stream,

                                             int len);

 /**

  *  The calculated values in this structure are calculated by SDL_OpenAudio().

  */

 typedef struct SDL_AudioSpec

 {

     int freq;                   /**< DSP frequency -- samples per second */

     SDL_AudioFormat format;     /**< Audio data format */

     Uint8 channels;             /**< Number of channels: 1 mono, 2 stereo */

     Uint8 silence;              /**< Audio buffer silence value (calculated) */

     Uint16 samples;             /**< Audio buffer size in samples (power of 2) */

     Uint16 padding;             /**< Necessary for some compile environments */

     Uint32 size;                /**< Audio buffer size in bytes (calculated) */

     SDL_AudioCallback callback;

     void *userdata;

 } SDL_AudioSpec;

 struct SDL_AudioCVT;

 typedef void (SDLCALL * SDL_AudioFilter) (struct SDL_AudioCVT * cvt,

                                           SDL_AudioFormat format);

 /**

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

  */

 typedef struct SDL_AudioCVT

 {

     int needed;                 /**< Set to 1 if conversion possible */

     SDL_AudioFormat src_format; /**< Source audio format */

     SDL_AudioFormat dst_format; /**< Target audio format */

     double rate_incr;           /**< Rate conversion increment */

     Uint8 *buf;                 /**< Buffer to hold entire audio data */

     int len;                    /**< Length of original audio buffer */

     int len_cvt;                /**< Length of converted audio buffer */

     int len_mult;               /**< buffer must be len*len_mult big */

     double len_ratio;           /**< Given len, final size is len*len_ratio */

     SDL_AudioFilter filters[10];        /**< Filter list */

     int filter_index;           /**< Current audio conversion function */

 } SDL_AudioCVT;

 /* Function prototypes */

 /**

  *  \name Driver discovery functions

  *  

  *  These functions return the list of built in audio drivers, in the

  *  order that they are normally initialized by default.

  */

 /*@{*/

 extern DECLSPEC int SDLCALL SDL_GetNumAudioDrivers(void);

 extern DECLSPEC const char *SDLCALL SDL_GetAudioDriver(int index);

 /*@}*/

 /**

  *  \name Initialization and cleanup

  *  

  *  \internal 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().

  */

 /*@{*/

 extern DECLSPEC int SDLCALL SDL_AudioInit(const char *driver_name);

 extern DECLSPEC void SDLCALL SDL_AudioQuit(void);

 /*@}*/

 /**

  *  This function returns the name of the current audio driver, or NULL

  *  if no driver has been initialized.

  */

 extern DECLSPEC const char *SDLCALL SDL_GetCurrentAudioDriver(void);

 /**

  *  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 \c obtained.  If \c 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,

  *    - \c desired->freq should be the desired audio frequency in samples-per-

  *      second.

  *    - \c desired->format should be the desired audio format.

  *    - \c 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:  \code ms = (samples*1000)/freq \endcode

  *    - \c desired->size is the size in bytes of the audio buffer, and is

  *      calculated by SDL_OpenAudio().

  *    - \c desired->silence is the value used to set the buffer to silence,

  *      and is calculated by SDL_OpenAudio().

  *    - \c 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.

  *    - \c desired->userdata is passed as the first parameter to your callback

  *      function.

  *  

  *  The audio device starts out playing silence when it's opened, and should

  *  be enabled for playing by calling \c 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.

  */

 extern DECLSPEC int SDLCALL SDL_OpenAudio(SDL_AudioSpec * desired,

                                           SDL_AudioSpec * obtained);

 /**

  *  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.

  */

 typedef Uint32 SDL_AudioDeviceID;

 /**

  *  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()).

  */

 extern DECLSPEC int SDLCALL SDL_GetNumAudioDevices(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.

  */

 extern DECLSPEC const char *SDLCALL SDL_GetAudioDeviceName(int index,

                                                            int iscapture);

 /**

  *  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.

  *  

  *  \return 0 on error, a valid device ID that is >= 2 on success.

  *  

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

  */

 extern DECLSPEC SDL_AudioDeviceID SDLCALL SDL_OpenAudioDevice(const char

                                                               *device,

                                                               int iscapture,

                                                               const

                                                               SDL_AudioSpec *

                                                               desired,

                                                               SDL_AudioSpec *

                                                               obtained,

                                                               int

                                                               allowed_changes);

 /**

  *  \name Audio state

  *  

  *  Get the current audio state.

  */

 /*@{*/

 typedef enum

 {

     SDL_AUDIO_STOPPED = 0,

     SDL_AUDIO_PLAYING,

     SDL_AUDIO_PAUSED

 } SDL_AudioStatus;

 extern DECLSPEC SDL_AudioStatus SDLCALL SDL_GetAudioStatus(void);

 extern DECLSPEC SDL_AudioStatus SDLCALL

 SDL_GetAudioDeviceStatus(SDL_AudioDeviceID dev);

 /*@}*//*Audio State*/

 /**

  *  \name 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.

  */

 /*@{*/

 extern DECLSPEC void SDLCALL SDL_PauseAudio(int pause_on);

 extern DECLSPEC void SDLCALL SDL_PauseAudioDevice(SDL_AudioDeviceID dev,

                                                   int pause_on);

 /*@}*//*Pause audio functions*/

 /**

  *  This function loads a WAVE from the data source, automatically freeing

  *  that source if \c freesrc is non-zero.  For example, to load a WAVE file,

  *  you could do:

  *  \code

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

  *  \endcode

  *

  *  If this function succeeds, it returns the given SDL_AudioSpec,

  *  filled with the audio data format of the wave data, and sets

  *  \c *audio_buf to a malloc()'d buffer containing the audio data,

  *  and sets \c *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.

  */

 extern DECLSPEC SDL_AudioSpec *SDLCALL SDL_LoadWAV_RW(SDL_RWops * src,

                                                       int freesrc,

                                                       SDL_AudioSpec * spec,

                                                       Uint8 ** audio_buf,

                                                       Uint32 * audio_len);

 /** 

  *  Loads a WAV from a file.

  *  Compatibility convenience function.

  */

 #define SDL_LoadWAV(file, spec, audio_buf, audio_len) \

 	SDL_LoadWAV_RW(SDL_RWFromFile(file, "rb"),1, spec,audio_buf,audio_len)

 /**

  *  This function frees data previously allocated with SDL_LoadWAV_RW()

  */

 extern DECLSPEC void SDLCALL SDL_FreeWAV(Uint8 * audio_buf);

 /**

  *  This function takes a source format and rate and a destination format

  *  and rate, and initializes the \c cvt structure with information needed

  *  by SDL_ConvertAudio() to convert a buffer of audio data from one format

  *  to the other.

  *  

  *  \return -1 if the format conversion is not supported, 0 if there's

  *  no conversion needed, or 1 if the audio filter is set up.

  */

 extern DECLSPEC int SDLCALL 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);

 /**

  *  Once you have initialized the \c cvt structure using SDL_BuildAudioCVT(),

  *  created an audio buffer \c cvt->buf, and filled it with \c 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

  *  \c cvt->buf should be allocated after the \c cvt structure is initialized by

  *  SDL_BuildAudioCVT(), and should be \c cvt->len*cvt->len_mult bytes long.

  */

 extern DECLSPEC int SDLCALL SDL_ConvertAudio(SDL_AudioCVT * cvt);

 #define SDL_MIX_MAXVOLUME 128

 /**

  *  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.

  */

 extern DECLSPEC void SDLCALL SDL_MixAudio(Uint8 * dst, const Uint8 * src,

                                           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.

  */

 extern DECLSPEC void SDLCALL SDL_MixAudioFormat(Uint8 * dst,

                                                 const Uint8 * src,

                                                 SDL_AudioFormat format,

                                                 Uint32 len, int volume);

 /**

  *  \name 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.

  */

 /*@{*/

 extern DECLSPEC void SDLCALL SDL_LockAudio(void);

 extern DECLSPEC void SDLCALL SDL_LockAudioDevice(SDL_AudioDeviceID dev);

 extern DECLSPEC void SDLCALL SDL_UnlockAudio(void);

 extern DECLSPEC void SDLCALL SDL_UnlockAudioDevice(SDL_AudioDeviceID dev);

 /*@}*//*Audio lock functions*/

 /**

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

  */

 extern DECLSPEC void SDLCALL SDL_CloseAudio(void);

 extern DECLSPEC void SDLCALL SDL_CloseAudioDevice(SDL_AudioDeviceID dev);

 /**

  * \return 1 if audio device is still functioning, zero if not, -1 on error.

  */

 extern DECLSPEC int SDLCALL SDL_AudioDeviceConnected(SDL_AudioDeviceID dev);

 /* Ends C function definitions when using C++ */

 #ifdef __cplusplus

 /* *INDENT-OFF* */

 }

 /* *INDENT-ON* */

 #endif

 #include "close_code.h"

 #endif /* _SDL_audio_h */

 /* vi: set ts=4 sw=4 expandtab: */