SDL_mixer.h
author Ryan C. Gordon <icculus@icculus.org>
Sun, 09 Mar 2008 06:35:09 +0000
changeset 384 51d7d7729faf
parent 382 50501e45c57b
child 386 695494546b3c
permissions -rw-r--r--
MUS_FLAC was stuck in the middle of the Mix_MusicType enum, instead of the end,
which would break binary compatibility.

Fixes Bugzilla #565.
     1 /*
     2     SDL_mixer:  An audio mixer library based on the SDL library
     3     Copyright (C) 1997-2004 Sam Lantinga
     4 
     5     This library is free software; you can redistribute it and/or
     6     modify it under the terms of the GNU Library General Public
     7     License as published by the Free Software Foundation; either
     8     version 2 of the License, or (at your option) any later version.
     9 
    10     This library is distributed in the hope that it will be useful,
    11     but WITHOUT ANY WARRANTY; without even the implied warranty of
    12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    13     Library General Public License for more details.
    14 
    15     You should have received a copy of the GNU Library General Public
    16     License along with this library; if not, write to the Free
    17     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
    18 
    19     Sam Lantinga
    20     slouken@libsdl.org
    21 */
    22 
    23 /* $Id$ */
    24 
    25 #ifndef _SDL_MIXER_H
    26 #define _SDL_MIXER_H
    27 
    28 #include "SDL_types.h"
    29 #include "SDL_rwops.h"
    30 #include "SDL_audio.h"
    31 #include "SDL_endian.h"
    32 #include "SDL_version.h"
    33 #include "begin_code.h"
    34 
    35 /* Set up for C function definitions, even when using C++ */
    36 #ifdef __cplusplus
    37 extern "C" {
    38 #endif
    39 
    40 /* Printable format: "%d.%d.%d", MAJOR, MINOR, PATCHLEVEL
    41 */
    42 #define SDL_MIXER_MAJOR_VERSION	1
    43 #define SDL_MIXER_MINOR_VERSION	2
    44 #define SDL_MIXER_PATCHLEVEL	8
    45 
    46 /* This macro can be used to fill a version structure with the compile-time
    47  * version of the SDL_mixer library.
    48  */
    49 #define SDL_MIXER_VERSION(X)						\
    50 {									\
    51 	(X)->major = SDL_MIXER_MAJOR_VERSION;				\
    52 	(X)->minor = SDL_MIXER_MINOR_VERSION;				\
    53 	(X)->patch = SDL_MIXER_PATCHLEVEL;				\
    54 }
    55 
    56 /* Backwards compatibility */
    57 #define MIX_MAJOR_VERSION	SDL_MIXER_MAJOR_VERSION
    58 #define MIX_MINOR_VERSION	SDL_MIXER_MINOR_VERSION
    59 #define MIX_PATCHLEVEL		SDL_MIXER_PATCHLEVEL
    60 #define MIX_VERSION(X)		SDL_MIXER_VERSION(X)
    61 
    62 /* This function gets the version of the dynamically linked SDL_mixer library.
    63    it should NOT be used to fill a version structure, instead you should
    64    use the SDL_MIXER_VERSION() macro.
    65  */
    66 extern DECLSPEC const SDL_version * SDLCALL Mix_Linked_Version(void);
    67 
    68 
    69 /* The default mixer has 8 simultaneous mixing channels */
    70 #ifndef MIX_CHANNELS
    71 #define MIX_CHANNELS	8
    72 #endif
    73 
    74 /* Good default values for a PC soundcard */
    75 #define MIX_DEFAULT_FREQUENCY	22050
    76 #if SDL_BYTEORDER == SDL_LIL_ENDIAN
    77 #define MIX_DEFAULT_FORMAT	AUDIO_S16LSB
    78 #else
    79 #define MIX_DEFAULT_FORMAT	AUDIO_S16MSB
    80 #endif
    81 #define MIX_DEFAULT_CHANNELS	2
    82 #define MIX_MAX_VOLUME		128	/* Volume of a chunk */
    83 
    84 /* The internal format for an audio chunk */
    85 typedef struct Mix_Chunk {
    86 	int allocated;
    87 	Uint8 *abuf;
    88 	Uint32 alen;
    89 	Uint8 volume;		/* Per-sample volume, 0-128 */
    90 } Mix_Chunk;
    91 
    92 /* The different fading types supported */
    93 typedef enum {
    94 	MIX_NO_FADING,
    95 	MIX_FADING_OUT,
    96 	MIX_FADING_IN
    97 } Mix_Fading;
    98 
    99 typedef enum {
   100 	MUS_NONE,
   101 	MUS_CMD,
   102 	MUS_WAV,
   103 	MUS_MOD,
   104 	MUS_MID,
   105 	MUS_OGG,
   106 	MUS_MP3,
   107 	MUS_MP3_MAD,
   108 	MUS_FLAC,
   109 } Mix_MusicType;
   110 
   111 /* The internal format for a music chunk interpreted via mikmod */
   112 typedef struct _Mix_Music Mix_Music;
   113 
   114 /* Open the mixer with a certain audio format */
   115 extern DECLSPEC int SDLCALL Mix_OpenAudio(int frequency, Uint16 format, int channels,
   116 							int chunksize);
   117 
   118 /* Dynamically change the number of channels managed by the mixer.
   119    If decreasing the number of channels, the upper channels are
   120    stopped.
   121    This function returns the new number of allocated channels.
   122  */
   123 extern DECLSPEC int SDLCALL Mix_AllocateChannels(int numchans);
   124 
   125 /* Find out what the actual audio device parameters are.
   126    This function returns 1 if the audio has been opened, 0 otherwise.
   127  */
   128 extern DECLSPEC int SDLCALL Mix_QuerySpec(int *frequency,Uint16 *format,int *channels);
   129 
   130 /* Load a wave file or a music (.mod .s3m .it .xm) file */
   131 extern DECLSPEC Mix_Chunk * SDLCALL Mix_LoadWAV_RW(SDL_RWops *src, int freesrc);
   132 #define Mix_LoadWAV(file)	Mix_LoadWAV_RW(SDL_RWFromFile(file, "rb"), 1)
   133 extern DECLSPEC Mix_Music * SDLCALL Mix_LoadMUS(const char *file);
   134 
   135 /* Load a music file from an SDL_RWop object (Ogg and MikMod specific currently)
   136    Matt Campbell (matt@campbellhome.dhs.org) April 2000 */
   137 extern DECLSPEC Mix_Music * SDLCALL Mix_LoadMUS_RW(SDL_RWops *rw);
   138 
   139 /* Load a wave file of the mixer format from a memory buffer */
   140 extern DECLSPEC Mix_Chunk * SDLCALL Mix_QuickLoad_WAV(Uint8 *mem);
   141 
   142 /* Load raw audio data of the mixer format from a memory buffer */
   143 extern DECLSPEC Mix_Chunk * SDLCALL Mix_QuickLoad_RAW(Uint8 *mem, Uint32 len);
   144 
   145 /* Free an audio chunk previously loaded */
   146 extern DECLSPEC void SDLCALL Mix_FreeChunk(Mix_Chunk *chunk);
   147 extern DECLSPEC void SDLCALL Mix_FreeMusic(Mix_Music *music);
   148 
   149 /* Find out the music format of a mixer music, or the currently playing
   150    music, if 'music' is NULL.
   151 */
   152 extern DECLSPEC Mix_MusicType SDLCALL Mix_GetMusicType(const Mix_Music *music);
   153 
   154 /* Set a function that is called after all mixing is performed.
   155    This can be used to provide real-time visual display of the audio stream
   156    or add a custom mixer filter for the stream data.
   157 */
   158 extern DECLSPEC void SDLCALL Mix_SetPostMix(void (*mix_func)
   159                              (void *udata, Uint8 *stream, int len), void *arg);
   160 
   161 /* Add your own music player or additional mixer function.
   162    If 'mix_func' is NULL, the default music player is re-enabled.
   163  */
   164 extern DECLSPEC void SDLCALL Mix_HookMusic(void (*mix_func)
   165                           (void *udata, Uint8 *stream, int len), void *arg);
   166 
   167 /* Add your own callback when the music has finished playing.
   168    This callback is only called if the music finishes naturally.
   169  */
   170 extern DECLSPEC void SDLCALL Mix_HookMusicFinished(void (*music_finished)(void));
   171 
   172 /* Get a pointer to the user data for the current music hook */
   173 extern DECLSPEC void * SDLCALL Mix_GetMusicHookData(void);
   174 
   175 /*
   176  * Add your own callback when a channel has finished playing. NULL
   177  *  to disable callback. The callback may be called from the mixer's audio 
   178  *  callback or it could be called as a result of Mix_HaltChannel(), etc.
   179  *  do not call SDL_LockAudio() from this callback; you will either be 
   180  *  inside the audio callback, or SDL_mixer will explicitly lock the audio
   181  *  before calling your callback.
   182  */
   183 extern DECLSPEC void SDLCALL Mix_ChannelFinished(void (*channel_finished)(int channel));
   184 
   185 
   186 /* Special Effects API by ryan c. gordon. (icculus@icculus.org) */
   187 
   188 #define MIX_CHANNEL_POST  -2
   189 
   190 /* This is the format of a special effect callback:
   191  *
   192  *   myeffect(int chan, void *stream, int len, void *udata);
   193  *
   194  * (chan) is the channel number that your effect is affecting. (stream) is
   195  *  the buffer of data to work upon. (len) is the size of (stream), and
   196  *  (udata) is a user-defined bit of data, which you pass as the last arg of
   197  *  Mix_RegisterEffect(), and is passed back unmolested to your callback.
   198  *  Your effect changes the contents of (stream) based on whatever parameters
   199  *  are significant, or just leaves it be, if you prefer. You can do whatever
   200  *  you like to the buffer, though, and it will continue in its changed state
   201  *  down the mixing pipeline, through any other effect functions, then finally
   202  *  to be mixed with the rest of the channels and music for the final output
   203  *  stream.
   204  *
   205  * DO NOT EVER call SDL_LockAudio() from your callback function!
   206  */
   207 typedef void (*Mix_EffectFunc_t)(int chan, void *stream, int len, void *udata);
   208 
   209 /*
   210  * This is a callback that signifies that a channel has finished all its
   211  *  loops and has completed playback. This gets called if the buffer
   212  *  plays out normally, or if you call Mix_HaltChannel(), implicitly stop
   213  *  a channel via Mix_AllocateChannels(), or unregister a callback while
   214  *  it's still playing.
   215  *
   216  * DO NOT EVER call SDL_LockAudio() from your callback function!
   217  */
   218 typedef void (*Mix_EffectDone_t)(int chan, void *udata);
   219 
   220 
   221 /* Register a special effect function. At mixing time, the channel data is
   222  *  copied into a buffer and passed through each registered effect function.
   223  *  After it passes through all the functions, it is mixed into the final
   224  *  output stream. The copy to buffer is performed once, then each effect
   225  *  function performs on the output of the previous effect. Understand that
   226  *  this extra copy to a buffer is not performed if there are no effects
   227  *  registered for a given chunk, which saves CPU cycles, and any given
   228  *  effect will be extra cycles, too, so it is crucial that your code run
   229  *  fast. Also note that the data that your function is given is in the
   230  *  format of the sound device, and not the format you gave to Mix_OpenAudio(),
   231  *  although they may in reality be the same. This is an unfortunate but
   232  *  necessary speed concern. Use Mix_QuerySpec() to determine if you can
   233  *  handle the data before you register your effect, and take appropriate
   234  *  actions.
   235  * You may also specify a callback (Mix_EffectDone_t) that is called when
   236  *  the channel finishes playing. This gives you a more fine-grained control
   237  *  than Mix_ChannelFinished(), in case you need to free effect-specific
   238  *  resources, etc. If you don't need this, you can specify NULL.
   239  * You may set the callbacks before or after calling Mix_PlayChannel().
   240  * Things like Mix_SetPanning() are just internal special effect functions,
   241  *  so if you are using that, you've already incurred the overhead of a copy
   242  *  to a separate buffer, and that these effects will be in the queue with
   243  *  any functions you've registered. The list of registered effects for a
   244  *  channel is reset when a chunk finishes playing, so you need to explicitly
   245  *  set them with each call to Mix_PlayChannel*().
   246  * You may also register a special effect function that is to be run after
   247  *  final mixing occurs. The rules for these callbacks are identical to those
   248  *  in Mix_RegisterEffect, but they are run after all the channels and the
   249  *  music have been mixed into a single stream, whereas channel-specific
   250  *  effects run on a given channel before any other mixing occurs. These
   251  *  global effect callbacks are call "posteffects". Posteffects only have
   252  *  their Mix_EffectDone_t function called when they are unregistered (since
   253  *  the main output stream is never "done" in the same sense as a channel).
   254  *  You must unregister them manually when you've had enough. Your callback
   255  *  will be told that the channel being mixed is (MIX_CHANNEL_POST) if the
   256  *  processing is considered a posteffect.
   257  *
   258  * After all these effects have finished processing, the callback registered
   259  *  through Mix_SetPostMix() runs, and then the stream goes to the audio
   260  *  device. 
   261  *
   262  * DO NOT EVER call SDL_LockAudio() from your callback function!
   263  *
   264  * returns zero if error (no such channel), nonzero if added.
   265  *  Error messages can be retrieved from Mix_GetError().
   266  */
   267 extern DECLSPEC int SDLCALL Mix_RegisterEffect(int chan, Mix_EffectFunc_t f,
   268 					Mix_EffectDone_t d, void *arg);
   269 
   270 
   271 /* You may not need to call this explicitly, unless you need to stop an
   272  *  effect from processing in the middle of a chunk's playback.
   273  * Posteffects are never implicitly unregistered as they are for channels,
   274  *  but they may be explicitly unregistered through this function by
   275  *  specifying MIX_CHANNEL_POST for a channel.
   276  * returns zero if error (no such channel or effect), nonzero if removed.
   277  *  Error messages can be retrieved from Mix_GetError().
   278  */
   279 extern DECLSPEC int SDLCALL Mix_UnregisterEffect(int channel, Mix_EffectFunc_t f);
   280 
   281 
   282 /* You may not need to call this explicitly, unless you need to stop all
   283  *  effects from processing in the middle of a chunk's playback. Note that
   284  *  this will also shut off some internal effect processing, since
   285  *  Mix_SetPanning() and others may use this API under the hood. This is
   286  *  called internally when a channel completes playback.
   287  * Posteffects are never implicitly unregistered as they are for channels,
   288  *  but they may be explicitly unregistered through this function by
   289  *  specifying MIX_CHANNEL_POST for a channel.
   290  * returns zero if error (no such channel), nonzero if all effects removed.
   291  *  Error messages can be retrieved from Mix_GetError().
   292  */
   293 extern DECLSPEC int SDLCALL Mix_UnregisterAllEffects(int channel);
   294 
   295 
   296 #define MIX_EFFECTSMAXSPEED  "MIX_EFFECTSMAXSPEED"
   297 
   298 /*
   299  * These are the internally-defined mixing effects. They use the same API that
   300  *  effects defined in the application use, but are provided here as a
   301  *  convenience. Some effects can reduce their quality or use more memory in
   302  *  the name of speed; to enable this, make sure the environment variable
   303  *  MIX_EFFECTSMAXSPEED (see above) is defined before you call
   304  *  Mix_OpenAudio().
   305  */
   306 
   307 
   308 /* Set the panning of a channel. The left and right channels are specified
   309  *  as integers between 0 and 255, quietest to loudest, respectively.
   310  *
   311  * Technically, this is just individual volume control for a sample with
   312  *  two (stereo) channels, so it can be used for more than just panning.
   313  *  If you want real panning, call it like this:
   314  *
   315  *   Mix_SetPanning(channel, left, 255 - left);
   316  *
   317  * ...which isn't so hard.
   318  *
   319  * Setting (channel) to MIX_CHANNEL_POST registers this as a posteffect, and
   320  *  the panning will be done to the final mixed stream before passing it on
   321  *  to the audio device.
   322  *
   323  * This uses the Mix_RegisterEffect() API internally, and returns without
   324  *  registering the effect function if the audio device is not configured
   325  *  for stereo output. Setting both (left) and (right) to 255 causes this
   326  *  effect to be unregistered, since that is the data's normal state.
   327  *
   328  * returns zero if error (no such channel or Mix_RegisterEffect() fails),
   329  *  nonzero if panning effect enabled. Note that an audio device in mono
   330  *  mode is a no-op, but this call will return successful in that case.
   331  *  Error messages can be retrieved from Mix_GetError().
   332  */
   333 extern DECLSPEC int SDLCALL Mix_SetPanning(int channel, Uint8 left, Uint8 right);
   334 
   335 
   336 /* Set the position of a channel. (angle) is an integer from 0 to 360, that
   337  *  specifies the location of the sound in relation to the listener. (angle)
   338  *  will be reduced as neccesary (540 becomes 180 degrees, -100 becomes 260).
   339  *  Angle 0 is due north, and rotates clockwise as the value increases.
   340  *  For efficiency, the precision of this effect may be limited (angles 1
   341  *  through 7 might all produce the same effect, 8 through 15 are equal, etc).
   342  *  (distance) is an integer between 0 and 255 that specifies the space
   343  *  between the sound and the listener. The larger the number, the further
   344  *  away the sound is. Using 255 does not guarantee that the channel will be
   345  *  culled from the mixing process or be completely silent. For efficiency,
   346  *  the precision of this effect may be limited (distance 0 through 5 might
   347  *  all produce the same effect, 6 through 10 are equal, etc). Setting (angle)
   348  *  and (distance) to 0 unregisters this effect, since the data would be
   349  *  unchanged.
   350  *
   351  * If you need more precise positional audio, consider using OpenAL for
   352  *  spatialized effects instead of SDL_mixer. This is only meant to be a
   353  *  basic effect for simple "3D" games.
   354  *
   355  * If the audio device is configured for mono output, then you won't get
   356  *  any effectiveness from the angle; however, distance attenuation on the
   357  *  channel will still occur. While this effect will function with stereo
   358  *  voices, it makes more sense to use voices with only one channel of sound,
   359  *  so when they are mixed through this effect, the positioning will sound
   360  *  correct. You can convert them to mono through SDL before giving them to
   361  *  the mixer in the first place if you like.
   362  *
   363  * Setting (channel) to MIX_CHANNEL_POST registers this as a posteffect, and
   364  *  the positioning will be done to the final mixed stream before passing it
   365  *  on to the audio device.
   366  *
   367  * This is a convenience wrapper over Mix_SetDistance() and Mix_SetPanning().
   368  *
   369  * returns zero if error (no such channel or Mix_RegisterEffect() fails),
   370  *  nonzero if position effect is enabled.
   371  *  Error messages can be retrieved from Mix_GetError().
   372  */
   373 extern DECLSPEC int SDLCALL Mix_SetPosition(int channel, Sint16 angle, Uint8 distance);
   374 
   375 
   376 /* Set the "distance" of a channel. (distance) is an integer from 0 to 255
   377  *  that specifies the location of the sound in relation to the listener.
   378  *  Distance 0 is overlapping the listener, and 255 is as far away as possible
   379  *  A distance of 255 does not guarantee silence; in such a case, you might
   380  *  want to try changing the chunk's volume, or just cull the sample from the
   381  *  mixing process with Mix_HaltChannel().
   382  * For efficiency, the precision of this effect may be limited (distances 1
   383  *  through 7 might all produce the same effect, 8 through 15 are equal, etc).
   384  *  (distance) is an integer between 0 and 255 that specifies the space
   385  *  between the sound and the listener. The larger the number, the further
   386  *  away the sound is.
   387  * Setting (distance) to 0 unregisters this effect, since the data would be
   388  *  unchanged.
   389  * If you need more precise positional audio, consider using OpenAL for
   390  *  spatialized effects instead of SDL_mixer. This is only meant to be a
   391  *  basic effect for simple "3D" games.
   392  *
   393  * Setting (channel) to MIX_CHANNEL_POST registers this as a posteffect, and
   394  *  the distance attenuation will be done to the final mixed stream before
   395  *  passing it on to the audio device.
   396  *
   397  * This uses the Mix_RegisterEffect() API internally.
   398  *
   399  * returns zero if error (no such channel or Mix_RegisterEffect() fails),
   400  *  nonzero if position effect is enabled.
   401  *  Error messages can be retrieved from Mix_GetError().
   402  */
   403 extern DECLSPEC int SDLCALL Mix_SetDistance(int channel, Uint8 distance);
   404 
   405 
   406 /*
   407  * !!! FIXME : Haven't implemented, since the effect goes past the
   408  *              end of the sound buffer. Will have to think about this.
   409  *               --ryan.
   410  */
   411 #if 0
   412 /* Causes an echo effect to be mixed into a sound. (echo) is the amount
   413  *  of echo to mix. 0 is no echo, 255 is infinite (and probably not
   414  *  what you want).
   415  *
   416  * Setting (channel) to MIX_CHANNEL_POST registers this as a posteffect, and
   417  *  the reverbing will be done to the final mixed stream before passing it on
   418  *  to the audio device.
   419  *
   420  * This uses the Mix_RegisterEffect() API internally. If you specify an echo
   421  *  of zero, the effect is unregistered, as the data is already in that state.
   422  *
   423  * returns zero if error (no such channel or Mix_RegisterEffect() fails),
   424  *  nonzero if reversing effect is enabled.
   425  *  Error messages can be retrieved from Mix_GetError().
   426  */
   427 extern no_parse_DECLSPEC int SDLCALL Mix_SetReverb(int channel, Uint8 echo);
   428 #endif
   429 
   430 /* Causes a channel to reverse its stereo. This is handy if the user has his
   431  *  speakers hooked up backwards, or you would like to have a minor bit of
   432  *  psychedelia in your sound code.  :)  Calling this function with (flip)
   433  *  set to non-zero reverses the chunks's usual channels. If (flip) is zero,
   434  *  the effect is unregistered.
   435  *
   436  * This uses the Mix_RegisterEffect() API internally, and thus is probably
   437  *  more CPU intensive than having the user just plug in his speakers
   438  *  correctly. Mix_SetReverseStereo() returns without registering the effect
   439  *  function if the audio device is not configured for stereo output.
   440  *
   441  * If you specify MIX_CHANNEL_POST for (channel), then this the effect is used
   442  *  on the final mixed stream before sending it on to the audio device (a
   443  *  posteffect).
   444  *
   445  * returns zero if error (no such channel or Mix_RegisterEffect() fails),
   446  *  nonzero if reversing effect is enabled. Note that an audio device in mono
   447  *  mode is a no-op, but this call will return successful in that case.
   448  *  Error messages can be retrieved from Mix_GetError().
   449  */
   450 extern DECLSPEC int SDLCALL Mix_SetReverseStereo(int channel, int flip);
   451 
   452 /* end of effects API. --ryan. */
   453 
   454 
   455 /* Reserve the first channels (0 -> n-1) for the application, i.e. don't allocate
   456    them dynamically to the next sample if requested with a -1 value below.
   457    Returns the number of reserved channels.
   458  */
   459 extern DECLSPEC int SDLCALL Mix_ReserveChannels(int num);
   460 
   461 /* Channel grouping functions */
   462 
   463 /* Attach a tag to a channel. A tag can be assigned to several mixer
   464    channels, to form groups of channels.
   465    If 'tag' is -1, the tag is removed (actually -1 is the tag used to
   466    represent the group of all the channels).
   467    Returns true if everything was OK.
   468  */
   469 extern DECLSPEC int SDLCALL Mix_GroupChannel(int which, int tag);
   470 /* Assign several consecutive channels to a group */
   471 extern DECLSPEC int SDLCALL Mix_GroupChannels(int from, int to, int tag);
   472 /* Finds the first available channel in a group of channels,
   473    returning -1 if none are available.
   474  */
   475 extern DECLSPEC int SDLCALL Mix_GroupAvailable(int tag);
   476 /* Returns the number of channels in a group. This is also a subtle
   477    way to get the total number of channels when 'tag' is -1
   478  */
   479 extern DECLSPEC int SDLCALL Mix_GroupCount(int tag);
   480 /* Finds the "oldest" sample playing in a group of channels */
   481 extern DECLSPEC int SDLCALL Mix_GroupOldest(int tag);
   482 /* Finds the "most recent" (i.e. last) sample playing in a group of channels */
   483 extern DECLSPEC int SDLCALL Mix_GroupNewer(int tag);
   484 
   485 /* Play an audio chunk on a specific channel.
   486    If the specified channel is -1, play on the first free channel.
   487    If 'loops' is greater than zero, loop the sound that many times.
   488    If 'loops' is -1, loop inifinitely (~65000 times).
   489    Returns which channel was used to play the sound.
   490 */
   491 #define Mix_PlayChannel(channel,chunk,loops) Mix_PlayChannelTimed(channel,chunk,loops,-1)
   492 /* The same as above, but the sound is played at most 'ticks' milliseconds */
   493 extern DECLSPEC int SDLCALL Mix_PlayChannelTimed(int channel, Mix_Chunk *chunk, int loops, int ticks);
   494 extern DECLSPEC int SDLCALL Mix_PlayMusic(Mix_Music *music, int loops);
   495 
   496 /* Fade in music or a channel over "ms" milliseconds, same semantics as the "Play" functions */
   497 extern DECLSPEC int SDLCALL Mix_FadeInMusic(Mix_Music *music, int loops, int ms);
   498 extern DECLSPEC int SDLCALL Mix_FadeInMusicPos(Mix_Music *music, int loops, int ms, double position);
   499 #define Mix_FadeInChannel(channel,chunk,loops,ms) Mix_FadeInChannelTimed(channel,chunk,loops,ms,-1)
   500 extern DECLSPEC int SDLCALL Mix_FadeInChannelTimed(int channel, Mix_Chunk *chunk, int loops, int ms, int ticks);
   501 
   502 /* Set the volume in the range of 0-128 of a specific channel or chunk.
   503    If the specified channel is -1, set volume for all channels.
   504    Returns the original volume.
   505    If the specified volume is -1, just return the current volume.
   506 */
   507 extern DECLSPEC int SDLCALL Mix_Volume(int channel, int volume);
   508 extern DECLSPEC int SDLCALL Mix_VolumeChunk(Mix_Chunk *chunk, int volume);
   509 extern DECLSPEC int SDLCALL Mix_VolumeMusic(int volume);
   510 
   511 /* Halt playing of a particular channel */
   512 extern DECLSPEC int SDLCALL Mix_HaltChannel(int channel);
   513 extern DECLSPEC int SDLCALL Mix_HaltGroup(int tag);
   514 extern DECLSPEC int SDLCALL Mix_HaltMusic(void);
   515 
   516 /* Change the expiration delay for a particular channel.
   517    The sample will stop playing after the 'ticks' milliseconds have elapsed,
   518    or remove the expiration if 'ticks' is -1
   519 */
   520 extern DECLSPEC int SDLCALL Mix_ExpireChannel(int channel, int ticks);
   521 
   522 /* Halt a channel, fading it out progressively till it's silent
   523    The ms parameter indicates the number of milliseconds the fading
   524    will take.
   525  */
   526 extern DECLSPEC int SDLCALL Mix_FadeOutChannel(int which, int ms);
   527 extern DECLSPEC int SDLCALL Mix_FadeOutGroup(int tag, int ms);
   528 extern DECLSPEC int SDLCALL Mix_FadeOutMusic(int ms);
   529 
   530 /* Query the fading status of a channel */
   531 extern DECLSPEC Mix_Fading SDLCALL Mix_FadingMusic(void);
   532 extern DECLSPEC Mix_Fading SDLCALL Mix_FadingChannel(int which);
   533 
   534 /* Pause/Resume a particular channel */
   535 extern DECLSPEC void SDLCALL Mix_Pause(int channel);
   536 extern DECLSPEC void SDLCALL Mix_Resume(int channel);
   537 extern DECLSPEC int SDLCALL Mix_Paused(int channel);
   538 
   539 /* Pause/Resume the music stream */
   540 extern DECLSPEC void SDLCALL Mix_PauseMusic(void);
   541 extern DECLSPEC void SDLCALL Mix_ResumeMusic(void);
   542 extern DECLSPEC void SDLCALL Mix_RewindMusic(void);
   543 extern DECLSPEC int SDLCALL Mix_PausedMusic(void);
   544 
   545 /* Set the current position in the music stream.
   546    This returns 0 if successful, or -1 if it failed or isn't implemented.
   547    This function is only implemented for MOD music formats (set pattern
   548    order number) and for OGG music (set position in seconds), at the
   549    moment.
   550 */
   551 extern DECLSPEC int SDLCALL Mix_SetMusicPosition(double position);
   552 
   553 /* Check the status of a specific channel.
   554    If the specified channel is -1, check all channels.
   555 */
   556 extern DECLSPEC int SDLCALL Mix_Playing(int channel);
   557 extern DECLSPEC int SDLCALL Mix_PlayingMusic(void);
   558 
   559 /* Stop music and set external music playback command */
   560 extern DECLSPEC int SDLCALL Mix_SetMusicCMD(const char *command);
   561 
   562 /* Synchro value is set by MikMod from modules while playing */
   563 extern DECLSPEC int SDLCALL Mix_SetSynchroValue(int value);
   564 extern DECLSPEC int SDLCALL Mix_GetSynchroValue(void);
   565 
   566 /* Get the Mix_Chunk currently associated with a mixer channel
   567     Returns NULL if it's an invalid channel, or there's no chunk associated.
   568 */
   569 extern DECLSPEC Mix_Chunk * SDLCALL Mix_GetChunk(int channel);
   570 
   571 /* Close the mixer, halting all playing audio */
   572 extern DECLSPEC void SDLCALL Mix_CloseAudio(void);
   573 
   574 /* We'll use SDL for reporting errors */
   575 #define Mix_SetError	SDL_SetError
   576 #define Mix_GetError	SDL_GetError
   577 
   578 /* Ends C function definitions when using C++ */
   579 #ifdef __cplusplus
   580 }
   581 #endif
   582 #include "close_code.h"
   583 
   584 #endif /* _SDL_MIXER_H */