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Module Sdlmixer


module Sdlmixer: sig .. end
Simple multi-channel audio mixer
exception SDLmixer_exception of string
Exception used to report errors

General API


val version : unit -> Sdl.version
Get the version of the dynamically linked SDL_mixer library

type format =
| AUDIO_FORMAT_U8 (*Unsigned 8-bit samples*)
| AUDIO_FORMAT_S8 (*Signed 8-bit samples*)
| AUDIO_FORMAT_U16LSB (*Unsigned 16-bit samples*)
| AUDIO_FORMAT_S16LSB (*Signed 16-bit samples*)
| AUDIO_FORMAT_U16MSB (*As above, but big-endian byte order*)
| AUDIO_FORMAT_S16MSB (*As above, but big-endian byte order*)
| AUDIO_FORMAT_U16SYS (*Unsigned, native audio byte ordering*)
| AUDIO_FORMAT_S16SYS (*Signed, native audio byte ordering*)
Audio format flags

type channels =
| MONO
| STEREO 
val open_audio : ?freq:int ->
       ?format:format ->
       ?chunksize:int -> ?channels:channels -> unit -> unit
open_audio frequency format chunksize channels () opens the mixer with a certain audio format. 
val close_audio : unit -> unit
Close the mixer, halting all playing audio

type specs = {
   frequency : int;
   format : format;
   channels : channels;
} 
val query_specs : unit -> specs
Find out what the actual audio device parameters are.
Raises SDLmixer_exception if the audio has not been opened

Samples


type chunk 
val loadWAV : string -> chunk
Load a wave file
val loadWAV_from_mem : string -> chunk
val load_string : string -> chunk
Load a wave file of the mixer format from a memory buffer
val volume_chunk : chunk -> float
val setvolume_chunk : chunk -> float -> unit
val free_chunk : chunk -> unit
Free an audio chunk previously loaded

Channels


type channel = int 
val all_channels : channel
A special value for representing all channels (-1 actually).
val num_channels : unit -> int
Returns the number of channels currently allocated
val allocate_channels : int -> int
Dynamically change the number of channels managed by the mixer. If decreasing the number of channels, the upper channels are stopped.
Returns the new number of allocated channels
val play_channel : ?channel:channel ->
       ?loops:int -> ?ticks:float -> chunk -> unit
play_channel channel loops ticks chunk Play an audio chunk.

channel : channel to play on. If not specified, play on the first free channel.
loops : number of times to play the chunk. If -1, loop infinitely (~65000 times).
ticks : if specified, play for at most 'ticks' seconds.
val play_sound : chunk -> unit
Play an audio chunk. Same as above, without the optional parameters
val fadein_channel : ?channel:channel ->
       ?loops:int -> ?ticks:float -> chunk -> float -> unit
fadein_channel channel loops ticks chunck ms : same as play_channel but fades in a over ms seconds.
val volume_channel : channel -> float
Returns the original volume of a specific channel, chunk or music
Returns float between 0 and 1.
val setvolume_channel : channel -> float -> unit
Sets the volume for specified channel or chunk. Volume is a float between 0 and 1. If lower than 0, nothing is done. If greater than 1, volume is set to 1
val pause_channel : channel -> unit
val resume_channel : channel -> unit
val halt_channel : channel -> unit
val expire_channel : channel -> float option -> unit
expire_channel channel ticks Change the expiration delay for a particular channel. The sample will stop playing after the 'ticks' seconds have elapsed, or remove the expiration if 'ticks' is None
val fadeout_channel : channel -> float -> unit
fadeout_channel channel ticks Halt a channel, fading it out progressively till it's silent The ms parameter indicates the number of seconds the fading will take.
val playing_channel : channel -> bool
val num_playing_channel : unit -> int
val paused_channel : channel -> bool
val num_paused_channel : unit -> int

type fade_status =
| NO_FADING
| FADING_OUT
| FADING_IN
The different fading types supported
val fading_channel : channel -> fade_status
Query the fading status of a channel

Groups


type group = int 
val default_group : group
The group tag used to represent the group of all the channels. Used to remove a group tag
val reserve_channels : int -> int
Reserve the first channels (0 -> n-1) for the application, i.e. don't allocate them dynamically to the next sample if no channel is specified (see Sdlmixer.play_channel).
Returns the number of reserved channels
val group_channel : channel -> group -> unit
Attach a group tag to a channel. A group tag can be assigned to several mixer channels, to form groups of channels. If group is default_group, the tag is removed.
val group_channels : from_c:channel -> to_c:channel -> group -> unit
Same as above but for a range of channels.
val group_count : group -> int
Returns the number of channels in a group. This is also a subtle way to get the total number of channels when group is default_group.
val group_available : group -> channel
Finds the first available channel in a group of channels
Raises Not_found if none are available.
val group_oldest : group -> channel
Finds the "oldest" sample playing in a group of channels
val group_newer : group -> channel
Finds the "most recent" (i.e. last) sample playing in a group of channels
val fadeout_group : group -> float -> unit
fadeout_group group ticks Halt a group of channel, fading it out progressively till it's silent The ms parameter indicates the number of seconds the fading will take.
val halt_group : group -> unit

Music


type music

type music_kind =
| NONE
| CMD
| WAV
| MOD
| MID
| OGG
| MP3
The different music types supported
val load_music : string -> music
Load a music file (.mod .s3m .it .xm .ogg)
val free_music : music -> unit
Free music previously loaded
val play_music : ?loops:int -> music -> unit
Play a music chunk.

loops : number of times to play through the music
val fadein_music : ?loops:int -> music -> float -> unit
fadein_music chunck loops music ms : fade in music over ms seconds, same semantics as the play_music function
val volume_music : music -> float
val setvolume_music : music -> float -> unit
val pause_music : unit -> unit
val resume_music : unit -> unit
val rewind_music : unit -> unit
val set_music_cmd : string -> unit
Stop music and set external music playback command
val unset_music_cmd : unit -> unit
Turn off using an external command for music, returning to the internal music playing functionality
val halt_music : unit -> unit
val fadeout_music : float -> unit
fadeout_music ticks Halt the music, fading it out progressively till it's silent. The ms parameter indicates the number of seconds the fading will take.
val music_type : music option -> music_kind
Find out the music format of a mixer music, or the currently playing music, if parameter is None.
val playing_music : unit -> bool
val paused_music : unit -> bool
val fading_music : unit -> fade_status
Query the fading status of a music