DragonFly On-Line Manual Pages
ALLEGRO_AUDIO_STREAM(3) ALLEGRO_AUDIO_STREAM(3)
NAME
ALLEGRO_AUDIO_STREAM - Allegro 5 API
SYNOPSIS
#include <allegro5/allegro_audio.h>
typedef struct ALLEGRO_AUDIO_STREAM ALLEGRO_AUDIO_STREAM;
DESCRIPTION
An ALLEGRO_AUDIO_STREAM object is used to stream generated audio to the
sound device, in real-time. This is done by reading from a buffer,
which is split into a number of fragments. Whenever a fragment has
finished playing, the user can refill it with new data.
As with ALLEGRO_SAMPLE_INSTANCE(3) objects, streams store information
necessary for playback, so you may not play the same stream multiple
times simultaneously. Streams also need to be attached to an
ALLEGRO_VOICE(3) object, or to an ALLEGRO_MIXER(3) object which,
eventually, reaches an ALLEGRO_VOICE object.
While playing, you must periodically fill fragments with new audio
data. To know when a new fragment is ready to be filled, you can
either directly check with al_get_available_audio_stream_fragments(3),
or listen to events from the stream.
You can register an audio stream event source to an event queue; see
al_get_audio_stream_event_source(3). An
ALLEGRO_EVENT_AUDIO_STREAM_FRAGMENT event is generated whenever a new
fragment is ready. When you receive an event, use
al_get_audio_stream_fragment(3) to obtain a pointer to the fragment to
be filled. The size and format are determined by the parameters passed
to al_create_audio_stream(3).
If you're late with supplying new data, the stream will be silent until
new data is provided. You must call al_drain_audio_stream(3) when
you're finished with supplying data to the stream.
If the stream is created by al_load_audio_stream(3) then it can also
generate an ALLEGRO_EVENT_AUDIO_STREAM_FINISHED event if it reaches the
end of the file and is not set to loop.
Allegro reference manual ALLEGRO_AUDIO_STREAM(3)