Audio options:
  QEMU_AUDIO_DAC_FIXED_SETTINGS: boolean, default = 1
    Use fixed settings for host DAC
  QEMU_AUDIO_DAC_FIXED_FREQ: integer, default = 44100
    Frequency for fixed host DAC
  QEMU_AUDIO_DAC_FIXED_FMT: format, default = S16, (one of: U8 S8 U16 S16 U32 S32)
    Format for fixed host DAC
  QEMU_AUDIO_DAC_FIXED_CHANNELS: integer, default = 2
    Number of channels for fixed DAC (1 - mono, 2 - stereo)
  QEMU_AUDIO_DAC_VOICES: integer, default = 1
    Number of voices for DAC
  QEMU_AUDIO_ADC_FIXED_SETTINGS: boolean, default = 1
    Use fixed settings for host ADC
  QEMU_AUDIO_ADC_FIXED_FREQ: integer, default = 44100
    Frequency for fixed host ADC
  QEMU_AUDIO_ADC_FIXED_FMT: format, default = S16, (one of: U8 S8 U16 S16 U32 S32)
    Format for fixed host ADC
  QEMU_AUDIO_ADC_FIXED_CHANNELS: integer, default = 2
    Number of channels for fixed ADC (1 - mono, 2 - stereo)
  QEMU_AUDIO_ADC_VOICES: integer, default = 1
    Number of voices for ADC
  QEMU_AUDIO_TIMER_PERIOD: integer, default = 250
    Timer period in HZ (0 - use lowest possible)
  QEMU_AUDIO_PLIVE: boolean, default = 0
    (undocumented)
  QEMU_AUDIO_LOG_TO_MONITOR: boolean, default = 0
    print logging messages to monitor instead of stderr

Available drivers:
Name: dsound
Description: DirectSound http://wikipedia.org/wiki/DirectSound
Theoretically supports many playback voices
One capture voice
Options:
  QEMU_DSOUND_LOCK_RETRIES: integer, default = 1
    Number of times to attempt locking the buffer
  QEMU_DSOUND_RESTOURE_RETRIES: integer, default = 1
    Number of times to attempt restoring the buffer
  QEMU_DSOUND_GETSTATUS_RETRIES: integer, default = 1
    Number of times to attempt getting status of the buffer
  QEMU_DSOUND_SET_PRIMARY: boolean, default = 0
    Set the parameters of primary buffer
  QEMU_DSOUND_LATENCY_MILLIS: integer, default = 10
    (undocumented)
  QEMU_DSOUND_PRIMARY_FREQ: integer, default = 44100
    Primary buffer frequency
  QEMU_DSOUND_PRIMARY_CHANNELS: integer, default = 2
    Primary buffer number of channels (1 - mono, 2 - stereo)
  QEMU_DSOUND_PRIMARY_FMT: format, default = S16, (one of: U8 S8 U16 S16 U32 S32)
    Primary buffer format
  QEMU_DSOUND_BUFSIZE_OUT: integer, default = 16384
    (undocumented)
  QEMU_DSOUND_BUFSIZE_IN: integer, default = 16384
    (undocumented)

Name: sdl
Description: SDL http://www.libsdl.org
One playback voice
Does not support capture
Options:
  QEMU_SDL_SAMPLES: integer, default = 1024
    Size of SDL buffer in samples

Name: fmod
Description: FMOD 3.xx http://www.fmod.org
Theoretically supports many playback voices
Theoretically supports many capture voices
Options:
  QEMU_FMOD_DRV: string, default = (not set)
    FMOD driver
  QEMU_FMOD_FREQ: integer, default = 44100
    Default frequency
  QEMU_FMOD_SAMPLES: integer, default = 4096
    Buffer size in samples
  QEMU_FMOD_CHANNELS: integer, default = 2
    Number of default channels (1 - mono, 2 - stereo)
  QEMU_FMOD_BUFSIZE: integer, default = 0
    (undocumented)

Name: none
Description: Timer based audio emulation
Theoretically supports many playback voices
Theoretically supports many capture voices
No options

Name: wav
Description: WAV renderer http://wikipedia.org/wiki/WAV
One playback voice
Does not support capture
Options:
  QEMU_WAV_FREQUENCY: integer, default = 44100
    Frequency
  QEMU_WAV_FORMAT: format, default = S16, (one of: U8 S8 U16 S16 U32 S32)
    Format
  QEMU_WAV_DAC_FIXED_CHANNELS: integer, default = 2
    Number of channels (1 - mono, 2 - stereo)
  QEMU_WAV_PATH: string, default = qemu.wav
    Path to wave file

Options are settable through environment variables.
Example:
  set QEMU_AUDIO_DRV=wav
  set QEMU_WAV_PATH=c:\tune.wav
  qemu ...