<code>
typedef struct oss_audioinfo
{
  int dev;                      /* Audio device number */
  char name[64];
  int busy;                     /* 0, OPEN_READ, OPEN_WRITE or OPEN_READWRITE */
  int pid;
  int caps;                     /* DSP_CAP_INPUT, DSP_CAP_OUTPUT */
  int iformats, oformats;
  int magic;                    /* Reserved for internal use */
  char cmd[64];                 /* Command using the device (if known) */
  int card_number;
  int port_number;
  int mixer_dev;
  int real_device;              /* This is the right /dev/dsp# device to open */
  int enabled;                  /* 1=enabled, 0=device not ready at this moment */
  int flags;                    /* For internal use only - no practical meaning */
  int min_rate, max_rate;       /* Sample rate limits */
  int min_channels, max_channels;       /* Number of channels supported */
  int binding;                  /* DSP_BIND_FRONT, etc. 0 means undefined */
  int rate_source;
  char handle[32];
  int nrates, rates[20];        /* Please read the manual before using these */
  oss_longname_t song_name;     /* Song name (if given) */
  oss_label_t label_name;       /* Device label (if given) */
  int filler[195];
} oss_audioinfo;
</code>

This ioctl is meant to go straight to the hardware, reporting only what's supported natively by the hardware.  That rules out emulating SNDCTL_DSP_GETCAPS/GETFMTS, because they both depend on the intermediate channel interface.  Mailed netchild & ariff for advice.

| field |  TODO  |
| **dev** | unit number? |
| **name** | device_get_desc() |
| **busy** | examine read and write channel flags for CHN_F_BUSY |
| **pid** | XXX -- this depends on the channel opened; with virtual channels, multiple processes may have a single HW device |
| **caps** | XXX -- need way to get to driver capabilties, formats, etc. w/o touching channel interface |
| **iformats** | XXX -- same caveat as caps |
| **ofortmats** | XXX -- same caveat as caps |
| **cmd** | XXX -- see pid |
| **card_number** | set to -1 for now (not very useful; OSS docs recommend not using this field) |
| **song_name** | write SNDCTL_{GET,SET}SONG first |
| **label** | write SNDCTL_{GET,SET}LABEL first |
| **port_number** |  |
| **mixer_dev** |  |
| **real_device** | unit number -- corresponds to /dev/dspN |
| **devnode** | cdev->si_name |
| **enabled** | device_t dev->state >= DS_ATTACHED |
| **min_rate, max_rate** | XXX -- same caveat as caps |
| **min_channels, max_channels** | 1 = mono, 2 = stereo, etc.; XXX -- same caveat as caps |
| **binding** | not officially part of OSS; see SNDCTL_DSP_BIND_CHANNEL |
| **rate_source** | sample rate group?  unsure. |
| **handle** | constant identifier -- (ex: PCI slot number, etc.)  think about this later |
| **nrates, rates** | not exported by card drivers; would need to touch them all |