#ifndef __USBAUDIO_URB_H
  #define __USBAUDIO_URB_H
  
  void snd_usb_init_substream(struct snd_usb_stream *as,
  			    int stream,
  			    struct audioformat *fp);
  
  int snd_usb_init_substream_urbs(struct snd_usb_substream *subs,
  				unsigned int period_bytes,
  				unsigned int rate,
  				unsigned int frame_bits);
  
  void snd_usb_release_substream_urbs(struct snd_usb_substream *subs, int force);
  
  int snd_usb_substream_prepare(struct snd_usb_substream *subs,
  			      struct snd_pcm_runtime *runtime);
  
  int snd_usb_substream_playback_trigger(struct snd_pcm_substream *substream, int cmd);
  int snd_usb_substream_capture_trigger(struct snd_pcm_substream *substream, int cmd);
  
  #endif /* __USBAUDIO_URB_H */