External PCM plugin SDK

Overview

// global functions

int
snd_pcm_parse_control_id(
    snd_config_t* conf,
    snd_ctl_elem_id_t* ctl_id,
    int* cardp,
    int* cchannelsp,
    int* hwctlp
);

// macros

#define SND_PCM_PLUGIN_DEFINE_FUNC(plugin)
#define SND_PCM_PLUGIN_ENTRY(name)
#define SND_PCM_PLUGIN_SYMBOL(name)

Detailed Documentation

Global Functions

int
snd_pcm_parse_control_id(
    snd_config_t* conf,
    snd_ctl_elem_id_t* ctl_id,
    int* cardp,
    int* cchannelsp,
    int* hwctlp
)

Parse control element id from the config.

This function parses the given config tree to retrieve the control element id and the card index. It’s used by softvol. External PCM plugins can use this function for creating or assigining their controls.

cchannelsp and hwctlp arguments are optional. Set NULL if not necessary.

Parameters:

conf the config tree to parse
ctl_id the pointer to store the resultant control element id
cardp the pointer to store the card index
cchannelsp the pointer to store the number of channels (optional)
hwctlp the pointer to store the h/w control flag (optional)

Returns:

0 if successful, or a negative error code

Macros

#define SND_PCM_PLUGIN_DEFINE_FUNC(plugin)

Define the plugin

#define SND_PCM_PLUGIN_ENTRY(name)

Define the object entry for external PCM plugins

#define SND_PCM_PLUGIN_SYMBOL(name)

Define the symbols of the given plugin with versions