---
name: "ALLEGRO_AUDIO_STREAM"
section: "3alleg5"
platform: "linux"
package: "allegro5-doc"
version: "2:5.2.10.1+dfsg-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/ALLEGRO_AUDIO_STREAM/3alleg5"
---

# ALLEGRO\_AUDIO\_STREAM(3alleg5)

Allegro 5 API

## 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(3alleg5) 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\_MIXER(3alleg5), which, eventually, reaches an ALLEGRO\_VOICE(3alleg5) 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(3alleg5), 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(3alleg5). An ALLEGRO\_EVENT\_AUDIO\_STREAM\_FRAGMENT(3alleg5) event is generated whenever a new fragment is ready. When you receive an event, use al\_get\_audio\_stream\_fragment(3alleg5) 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(3alleg5).

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(3alleg5) when you’re finished with supplying data to the stream.

It is often a good idea to prefill the audio stream with data before ALLEGRO\_EVENT\_AUDIO\_STREAM\_FRAGMENT(3alleg5) events arrive. Here is a snippet that will fill the stream buffers with silence:

-

  ```
  ALLEGRO_AUDIO_STREAM *stream = al_create_audio_stream(num_buffers,
     samples_per_buffer, freq, depth, channel_conf);
  void *buf;
  while ((buf = al_get_audio_stream_fragment(stream))) {
     al_fill_silence(buf, samples_per_buffer, depth, channel_conf);
     al_set_audio_stream_fragment(stream, buf);
  }
  ```

If the stream is created by al\_load\_audio\_stream(3alleg5) or al\_play\_audio\_stream(3alleg5) then it will also generate an ALLEGRO\_EVENT\_AUDIO\_STREAM\_FINISHED(3alleg5) event if it reaches the end of the file and is not set to loop.