fade: Switch to modular mixer API.
[paraslash.git] / mix.h
1 /**
2 * Opaque structure which corresponds to an instance of a mixer.
3 *
4 * A pointer to a structure of this type is returned by ->open(). This pointer
5 * must be passed to most other methods of \ref struct mixer.
6 */
7 struct mixer_handle;
8
9 /**
10 * Operations provided by each mixer plugin.
11 */
12 struct mixer {
13 /** Called on startup, must fill in all other members. */
14 void (*init)(struct mixer *self);
15 /** Return a handle that can be passed to other methods. */
16 int (*open)(const char *dev, struct mixer_handle **handle);
17 /** Returns a string of all valid mixer channels. */
18 char *(*get_channels)(struct mixer_handle *handle);
19 /** Select the channel for subsequent get/set operations. */
20 int (*set_channel)(struct mixer_handle *handle,
21 const char *mixer_channel);
22 /** Return the (normalized) current value of the selected channel. */
23 int (*get)(struct mixer_handle *handle);
24 /** Change the value of the selected channel. */
25 int (*set)(struct mixer_handle *handle, int val);
26 /** Free all ressources associated with the given handle. */
27 void (*close)(struct mixer_handle **handle);
28 };