IupAudio
Creates an audio player. Plays one sound file through the default output device; several elements play at the same time and are mixed. It is not a visual element. Each element should be destroyed using IupDestroy.
Decodes WAV, FLAC, MP3 and Ogg Vorbis files.
In WebAssembly the page must be a secure context, and output is silent until the first click or key press when the page was not opened from a user gesture.
Initialization and Usage
The IupMediaOpen function must be called after
IupOpen. The "iupmedia.h" file must also be included in
the source code. The program must be linked to the media library
(iupmedia). In Go it needs the media build tag.
int IupMediaOpen(void);Returns: IUP_NOERROR, IUP_OPENED when already open, or IUP_ERROR when IupOpen was not called.
Creation
Ihandle* IupAudio(void);Returns: the identifier of the created element, or NULL if an error occurs.
Attributes
FILE (non-inheritable): Path of the file to play. Setting it stops the current playback and loads the new file, rewound to the start. If the file cannot be loaded, ERROR_CB is called and FILE returns NULL. NULL unloads the file.
PLAY (write-only): Starts playback, or resumes it after PAUSE. Ignored when no file is loaded.
PAUSE (write-only): Pauses playback keeping the current position.
STOP (write-only): Stops playback and rewinds to the start.
STATE (read-only): Returns "PLAYING", "PAUSED" or "STOPPED".
VOLUME (non-inheritable): Playback volume from 0 (silent) to 100. Default: "100".
PAN (non-inheritable): Stereo balance from -100 (left) to 100 (right). Default: "0".
PITCH (non-inheritable): Playback speed factor, greater than 0. Changes both speed and pitch. Default: "1.0".
LOOP (non-inheritable): Restarts from the beginning when the end is reached. Can be "YES" or "NO". Default: "NO". While "YES", PLAYEND_CB is not called.
POSITION (non-inheritable): Playback position in seconds, as a floating point number. Setting it seeks.
DURATION (read-only): Length of the loaded file in seconds, as a floating point number, or "0" when unknown.
CHANNELS, SAMPLERATE (read-only): Channel count and sample rate in Hz of the loaded file.
Callbacks
PLAYEND_CB: Called when playback reaches the end of the file. Not called after STOP, nor while LOOP is "YES".
int function(Ihandle *ih);ih: identifier of the element that activated the event.
Returns: IUP_CLOSE will be processed.
ERROR_CB: Called when a file cannot be loaded.
int function(Ihandle *ih, const char *message);ih: identifier of the element that activated the
event.
message: description of the failure.
Returns: IUP_CLOSE will be processed.
Both callbacks are called from the main loop.