Information about mixer routes
typedef struct snd_mixer_routes_s
{
    snd_mixer_eid_t eid;
    int32_t     routes, routes_size, routes_over;
    uint8_t     zero[4];            /* alignment -- zero fill */
    snd_mixer_eid_t *proutes;
    void        *pzero;             /* align pointers on 64-bits;
                                       point to NULL */
    uint8_t     reserved[128];      /* must be filled with zeroes */
}       snd_mixer_routes_t;
The snd_mixer_routes_t structure describes all of the routes in a mixer. You can fill this structure by calling snd_mixer_routes().
The members of the snd_mixer_routes_t structure include:
If proutes isn't NULL, snd_mixer_routes() stores the route IDs in the array.
QNX Neutrino