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mixer.h
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/*
MIXERLIB: An audio mixer library based on the SDL library
Copyright (C) 1997-1999 Sam Lantinga
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the Free
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
Sam Lantinga
5635-34 Springhouse Dr.
Pleasanton, CA 94588 (USA)
slouken@devolution.com
*/
#ifndef _MIXER_H_
#define _MIXER_H_
#include <SDL/SDL_types.h>
#include <SDL/SDL_rwops.h>
#include <SDL/SDL_audio.h>
#include <SDL/begin_code.h>
/* The default mixer has 8 simultaneous mixing channels */
#ifndef MIX_CHANNELS
#define MIX_CHANNELS 8
#endif
/* Good default values for a PC soundcard */
#define MIX_DEFAULT_FREQUENCY 22050
#define MIX_DEFAULT_FORMAT AUDIO_S16
#define MIX_DEFAULT_CHANNELS 2
#define MIX_MAX_VOLUME 128 /* Volume of a chunk */
/* The internal format for an audio chunk */
typedef struct {
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int allocated;
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Uint8 *abuf;
Uint32 alen;
Uint8 volume; /* Per-sample volume, 0-128 */
} Mix_Chunk;
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/* The different fading types supported */
typedef enum {
MIX_NO_FADING,
MIX_FADING_OUT,
MIX_FADING_IN
} Mix_Fading;
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/* The internal format for a music chunk interpreted via mikmod */
typedef struct _Mix_Music Mix_Music;
/* Open the mixer with a certain audio format */
extern int Mix_OpenAudio(int frequency, Uint16 format, int channels,
int chunksize);
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/* Dynamically change the number of channels managed by the mixer.
If decreasing the number of channels, the upper channels are
stopped.
This function returns the new number of allocated channels.
*/
extern int Mix_AllocateChannels(int numchans);
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/* Find out what the actual audio device parameters are.
This function returns 1 if the audio has been opened, 0 otherwise.
*/
extern int Mix_QuerySpec(int *frequency, Uint16 *format, int *channels);
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/* Load a wave file or a music (.mod .s3m .it .xm) file */
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extern Mix_Chunk *Mix_LoadWAV_RW(SDL_RWops *src, int freesrc);
#define Mix_LoadWAV(file) Mix_LoadWAV_RW(SDL_RWFromFile(file, "rb"), 1)
extern Mix_Music *Mix_LoadMUS(const char *file);
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/* Load a wave file of the mixer format from a memory buffer */
extern Mix_Chunk *Mix_QuickLoad_WAV(Uint8 *mem);
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/* Free an audio chunk previously loaded */
extern void Mix_FreeChunk(Mix_Chunk *chunk);
extern void Mix_FreeMusic(Mix_Music *music);
/* Add your own music player or additional mixer function.
If 'mix_func' is NULL, the default music player is re-enabled.
*/
extern void Mix_HookMusic(void (*mix_func)(void *udata, Uint8 *stream, int len),
void *arg);
/* Get a pointer to the user data for the current music hook */
extern void *Mix_GetMusicHookData(void);
/* Reserve the first channels (0 -> n-1) for the application, i.e. don't allocate
them dynamically to the next sample if requested with a -1 value below.
Returns the number of reserved channels.
*/
extern int Mix_ReserveChannels(int num);
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/* Channel grouping functions */
/* Attach a tag to a channel. A tag can be assigned to several mixer
channels, to form groups of channels.
If 'tag' is -1, the tag is removed (actually -1 is the tag used to
represent the group of all the channels).
Returns true if everything was OK.
*/
extern int Mix_GroupChannel(int which, int tag);
/* Assign several consecutive channels to a group */
extern int Mix_GroupChannels(int from, int to, int tag);
/* Finds the first available channel in a group of channels */
extern int Mix_GroupAvailable(int tag);
/* Returns the number of channels in a group. This is also a subtle
way to get the total number of channels when 'tag' is -1
*/
extern int Mix_GroupCount(int tag);
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/* Play an audio chunk on a specific channel.
If the specified channel is -1, play on the first free channel.
If 'loops' is greater than zero, loop the sound that many times.
If 'loops' is -1, loop inifinitely (~65000 times).
Returns which channel was used to play the sound.
*/
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#define Mix_PlayChannel(channel,chunk,loops) Mix_PlayChannelTimed(channel,chunk,loops,-1)
/* The same as above, but the sound is played at most 'ticks' milliseconds */
extern int Mix_PlayChannelTimed(int channel, Mix_Chunk *chunk, int loops, int ticks);
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extern int Mix_PlayMusic(Mix_Music *music, int loops);
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/* Fade in music or a channel over "ms" milliseconds, same semantics as the "Play" functions */
extern int Mix_FadeInMusic(Mix_Music *music, int loops, int ms);
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#define Mix_FadeInChannel(channel,chunk,loops,ms) Mix_FadeInChannelTimed(channel,chunk,loops,ms,-1)
extern int Mix_FadeInChannelTimed(int channel, Mix_Chunk *chunk, int loops, int ms, int ticks);
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/* Set the volume in the range of 0-128 of a specific channel or chunk.
If the specified channel is -1, set volume for all channels.
Returns the original volume.
If the specified volume is -1, just return the current volume.
*/
extern int Mix_Volume(int channel, int volume);
extern int Mix_VolumeChunk(Mix_Chunk *chunk, int volume);
extern int Mix_VolumeMusic(int volume);
/* Halt playing of a particular channel */
extern int Mix_HaltChannel(int channel);
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extern int Mix_HaltGroup(int tag);
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extern int Mix_HaltMusic(void);
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/* Change the expiration delay for a particular channel.
The sample will stop playing after the 'ticks' milliseconds have elapsed,
or remove the expiration if 'ticks' is -1
*/
extern int Mix_ExpireChannel(int channel, int ticks);
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/* Halt a channel, fading it out progressively till it's silent
The ms parameter indicates the number of milliseconds the fading
will take.
*/
extern int Mix_FadeOutChannel(int which, int ms);
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extern int Mix_FadeOutGroup(int tag, int ms);
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extern int Mix_FadeOutMusic(int ms);
/* Query the fading status of a channel */
extern Mix_Fading Mix_FadingMusic(void);
extern Mix_Fading Mix_FadingChannel(int which);
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/* Pause/Resume a particular channel */
extern void Mix_Pause(int channel);
extern void Mix_Resume(int channel);
/* Pause/Resume the music stream */
extern void Mix_PauseMusic(void);
extern void Mix_ResumeMusic(void);
extern void Mix_RewindMusic(void);
/* Check the status of a specific channel.
If the specified channel is -1, check all channels.
*/
extern int Mix_Playing(int channel);
extern int Mix_PlayingMusic(void);
/* Stop music and set external music playback command */
extern int Mix_SetMusicCMD(const char *command);
/* Close the mixer, halting all playing audio */
extern void Mix_CloseAudio(void);
/* We'll use SDL for reporting errors */
#define Mix_SetError SDL_SetError
#define Mix_GetError SDL_GetError
#include <SDL/close_code.h>
#endif /* _MIXER_H_ */